WO2012042407A2 - Solar energy production - Google Patents

Abstract

The system described collects solar radiation and produces electrical energy or mechanical energy that may be converted to electrical. The mechanical version has the capability to store energy for later use using compressed air. The system comprises: a) A field of reception reflection concentration and absorption of solar radiation based on the parabolic trough paradigm. It uses a rotating catenary reflector with receiver fixed to it or a dynamically tilted catenary type reflector or a fixed catenary reflector with rotating ( splitted ) collector. The main idea is to have a very cheap system for very big installations. b) A concentrated photo voltaic collector or a heat engine for the transformation of the temperature differential to mechanical energy. That engine makes use of a novel expansion compression element. The element may be used in compressed air motors ( e.g. for air cars and other utilities), compressors, Stirling - Ericsson engines, solar compressors - refrigerators, compressed air generators - UPS systems. By a devised method the element is applied to convert legacy engines ( gasoline, Diesel, compressors) to being pro-pulsed by compressed air at high efficiency By another any fixed displacement motor may be equipped with efficient variable power functionality and variable power regenerative breaking. The last method is used inside the solar heat engine in order to couple the compressor and expander part of the heat engine at variable power ratio being able to generate compressed air or consume it depending on needs.

Description

Solar energy generation

Logical structure and claimed priorities

The instant system is formed of a group of inventions divided previously in two applications forming a generic inventive system and concept that I try to implement. Priority is claimed from applications applied to the Greek office: a) GR20100100470 2010/08/27 System for the reception reflection concentration and absorption of solar radiation, b) GR20100100533 2010/09/27 Part of a reciprocating engine corresponding to the cylinder and piston, piston less , oil less, frictionless. Both of them should be meant incorporated by reference.

Besides the above applications new developments and problems in the application

GR20100100533 leaded to an application for a patent of addition ( not applied ) that is incorporated and merged with GR20100100533 into the current application. That application should have had the title: c) Motor part for the "isothermal" compression expansion, method for variable horsepower and variable regenerative breaking, method for the conversion of legacy engines to work by compressed air, uses in air motors, compressors, thermal engines of Stirling Ericsson type and solar systems.

The first application will not receive significant new disclosure, instead deeper explanations will be done on some aspects in order to help whoever wants to apply the ideas to do it better. On both parts of the patent ( the optical one and the engine one ) further review of prior art will be presented. Sources for my research was the Google search engine, the service

patents.***.com and some sites that reveal collectively many "solar" patents. Besides that the every day research added to prior art. It must be noted that the Greek office redirected the examination of GR20100100470 to the EPO for lack of examiner time. So the examination could be done only once relaying on the current text that includes GR20100100470. During the description I will strictly differentiate new and old claims and/or disclosures.

Scope of the invention.

The invention seeks to construct a solar energy farm of a small or medium and scalable size. Both photo voltaic and thermo-solar solutions may be used, in any case concentration is the big economizer. So for the field of reception we opt to uses concentrators. Thermo-solar plants of that kind are labeled as csp concentrated solar power systems. According to wikipedia under http://en.wikipedia.org/wiki/Concentrated_solar_power the main technologies are:

Parabolic trough Fresnel reflectors Dish Stirling Solar power tower

The solution we opt for the development of a solar energy generating station are based on the above basic idea: Use a flexible surface without supports in order to be able to deploy that surface on a field without acting on all the field. Any movement mechanism is in one place and doesn't complicate the construction in the entire field. Start: Translation of last version accepted by the Greek Office of GR20100100470 the original figure numbers are in brackets the new ones are created by adding 47000.

System for the reception reflection concentration and absorption of solar radiation

The invention refers to Concentrated Solar Power (thermal, photo-voltaic,chemical, or other).

Concentrated solar power techniques use mirrors or lenses to concentrate the solar radiation (light) in order to convert it into energy via thermal photo voltaic chemical or other process.

Concentration of light is obtained with parabolic mirrors or with heliostats versus the focus of the mirrors or using lenses (usually fresnel ones) or using arrays of plane of quasi-plane mirrors that move and concentrate the solar radiation ( fresnel linear reflectors - LFR ).

The above systems require specially manufactured parabolic mirrors ( or parabolic supports to adapt flexible reflective surfaces). Moreover the mirrors or lenses must move in order to track the sun ( plane version included). Similar systems have been constructed by Augustine Mouchot that in 1860 started to research the possibility to convert solar energy into mechanical and in 1878 exhibited during the International Paris exhibition the biggest engine of it's epoch for the production of steam using the sun. The above engine was critically studied later by Allessandro Annibale Battaglia. Battaglia deposited a patent request in 1884 with the name "Multiple solar collector". The most notorious ancestor of modern systems was constructed in the Meadi desert in Egypt ( 20 km from Cairo ) in 1912 from Frank Shuman ( 1862-1918 ) for the supply of a steam engine that was pumping water from the underground. Giovanni Francia believing that only with plane surfaces could be implemented big installations constructed between 1960 and 1965 installations with linear plane reflectors of the Fresnel type. [ I will dare to say ( in view of current developments) that afterwards "he lost the right way" and continued with 3D concentrating systems as that in patent US3466119 ( with the excessive cost that they imply )]

Further developments contain the patent of Peter Le Lievre 2007/1057923 A1 that refers to the system CLFR. Other prior art is the Italian patent 1021227 7/2/1975. A great resource for the story of the use of solar radiation is the Italian "center for the history of solar energy" from where I got aware of the aspects of the universal solar itinerary (http://www.ases.it/pub/silvi-fresnel.pdf ). The instant invention is based on the parabolic through example. That kind of paradigm makes use of a bi dimensional parabola that in one instance has it's axis pointed towards the sun and it's surface perpendicular to the earth surface. The parabola is translated along a line that is perpendicular to the surface of the parabola and parallel to the earth surface. In such a way is created a three-dimensional linear parabolic surface.

In this case sun tracking is done in one dimension and we have two angles: a) the angle that sun has with the horizon ( elevation ) and b) the angle that the solar rays projected on the earth surface have with the horizontal line that is perpendicular to the length of the linear parabola. The vertical angle that the sun makes with the horizon is tracked. The other angle isn't but cause of the linearity the focus of the reflected radiation is translated along the length of the linear parabola and so we have losses only at the edges ( the concentration is obtained on the focus line but a little bit translated). In any case we have losses resulting from the smaller phenomenical length (surface ) that the linear parabola shows to the sun compared to the full length that it would show if the tracking was done also rotating along a vertical axis the whole parabola.

Besides the aforementioned instance where the linear parabola has the direction east-west we have the possibility of a north-south direction. In this case the parabola at solar noon has it's bottom in the lowest position. The parabolic linear paradigm diminishes the tracking in one direction simplifying the mechanical construction ( instead of having to track 2 directions ).

Cause of the linearity along the length of the parabola we can have big dimensions in that direction. The basic drawback is that cause of the limited tracking we loose some energy that could be retained if the system was rotating along a vertical axis.

In any case the need for tracking in one direction puts limits on the size of the system and complicates the construction of fields of reception of huge dimensions.

The instant invention explores another direction:

We make use of flexible surfaces under field of forces that may give them their parabolic shape. The tracking problem is resolved in two different modes:

a) fixed reflectors with a focus that moves and is tracked in position and growth ( the growth is caused cause of the loss of focus ). b) dynamic modeling of the surfaces applying to them variable forces. The basic strategic idea that is behind the invention is the cost lowering in the big field and the transport of the complication of the tracking into a smaller field lowering in such a way the construction cost of an installation for the concentration of solar radiation. The basic improvement is the lowering of the costs per concentrated KW.

The invention In order to create a linear parabola makes use of a flexible surface ( for example reflective aluminum sheet) that in one instance has a rectangular parallelogram shape and is tied to two parallel and equal horizontal supports ( that may be at the same or different height selecting in such a way a different part of the parabola).

In the example of figure 47001 [1] the supports have an east-west direction ( we have also the possibility of the north-south direction). When the surface is hanged in such a way gets the catenary shape cause of the earth's gravitational field. The catenary shape is similar and non discernible from the parabolic one for the points that are at low angular positions from the base of the parabola. Compare the two equations ( χ^Λ2 and (cosh(x)-1 )/(cosh(1 )-1 ) ) for values of x from 0 to 1 ( angle less than 45 degrees with respect to the tangent to the lowest point of the curve ) ( figure 47011 [11]). So we use as modeling force the gravity and we have a quasi-parabola. When the sun is at 90 degrees ( if we where at the equator where the invention would be more effective ) our linear parabola concentrates all the reflected rays into her linear focus.

Using software to simulate the rays reflected from a bi dimensional parabola when is lighted by a light source at different angles we see that except for the 90 degrees position the rays do not converge ( or traverse ) a point, instead the focus grows and there is a minimal segment that concentrates all the reflected rays ( figures 47003 to 47009 [3 to 9]). The rays aren't uniformly distributed on that line ( surface ) and so the peripheral zones have less radiation ( energy ). The concentration of solar radiation is done in a line ( line in the bi dimensional section - but surface in the reality ) that moves roughly in a cycle with center the lowest point of the parabola ( base ) and radius the distance of the focus from the base. The tracking may be calculated with geometrical precision or may be calculated dynamically using software that maximizes in real time the temperature related to the position.

In figure 47002 [2] we see a system where the collector has one degree of freedom. We may have two degrees of freedom hanging the collector from two steel wire ropes ( or better said from more than two along the length of the parabola ). In such a way we can position the collector in any position ( figures 47013 47014 [13 14]).

To understand what happens exactly in a system that is setup to concentrate the sun rays when the sun is vertical let's study it geometrically.

Let's suppose we have two mirrors like in figure 47015 [15] that are inclined to the earth surface and when the sun rays fall vertically then they are concentrated into the point A.

We want to study the orbit of point A by changing the angle of the reflected rays.

If we change the angle of incidence of rays H1 and H2 then the reflected rays will have an equal angle variation. Which is the geometric field of points that have the same change of angle from points K1 and K2 ? We will start from the theorem that in the circle the angle formed with vertex a point that is on it and an arc on the circle is the half of the angle that the center of the circle makes with the same arc. Looking at figure 47021 [21] we see that if the point A moves on the circle that passes from the points K1 K2 and A then if we take the position A' then the angle A-K2- A' is the same with the angle A-K1-A because the angle K1-A-K2 is equal ( because looks to the same arc ) with the angle K1-A-K2. So considering the triangles K1-A-K2 and K1-A-K2 their angles differ of the same quantity ( while one diminishes the other augments by the same amount). So the focus of the radiation changes position on the circle that passes from the points K1-A-K2. Because in the case of the invention and referring to figure 47020 [20] we do not have only the points K1 and K2 but a sequence of couples of points we can draw the centered circle that passes from the point K0 and A ( that has as center the mid point between A and K0 ) and the circle that passes from the points K1-A-K2. The reflected radiation will stay between those two circles. We may design the circles for pairs of points either for the flat case or for the parabolic one ( the drawing changes a little bit because the points change in height ). Various parameters define the economical figures of the whole system and so determine the elements that have to be taken into consideration during the construction.

a) The cost of the reflective surface per surface unit ( including the supports and the land - that we consider negligible), b) The cost of the absorbing surface per surface unit (including supports and mechanisms). We have to know also the energy that the sun gives at different angles during the year per surface unit in our zone.

Having the above parameters we can optimize a given budget between the cost of reflective surface and absorbing surface in order to maximize the energy.

If we use a thermodynamic mechanism of conversion of the electromagnetic radiation into heat first and mechanical work after then we have to maximize the resulting work that depends also on the temperature at which is collected the radiation ( entropy considerations ) and that is related with the concentration of solar radiation at the point of absorption.

A little bit more analytically to be understood: If we select a very small surface of absorption of solar radiation then we will have a small cost in that part of the budget. But we will be unable to collect the maximum possible energy during all the day cause of the fact that the focus of the concentration will grow above the size of the absorption surface. If we select a very big surface then we will be able to absorb for more hours all the radiation or big part of it but maybe we'd had to use that budget instead to augment the reflection surface in order to collect more energy for less hours. There is also the thermodynamic part: If we can concentrate a lot the radiation then we can augment a lot the temperature.

By increasing the temperature grows the maximum thermodynamic efficiency that depends on ( (T2-T1 )/T2 ). But with the growth of the temperature we have bigger losses due to the radiation cause of black body radiation ( and thermal losses ). So the losses due to the black body radiation may be bigger than the growth of the relation (T2-T1 )/T2 and so it may be

counterproductive the over concentration of radiation. These are optimizations that must be done when a final system will be constructed but cannot be resolved actually because they depend on many variable parameters like the cost of materials thermal losses, kind of absorption surface ( thermodynamic solar evacuated tube, photo voltaic, chemical etc).

The ideal tracking orbit may be calculated geometrically but it may prove more effective to calculate it dynamically ( using temperature sensors and PC software and finding by try and trial the best trajectory). This approach will implicitly take into consideration also the last minimal aspect of the final installation. A more complex alternative solution ( figure 47010 [10] and figure 47012 [12] ) is to modify the field of forces in order to oblige the "parabola" to track the sun changing it's axis ( and eventually changing the distance between the support lines making use of mechanism like those used in solar tents ( figure 47010 [10]). Tracking may be implemented applying equal horizontal forces ( or also in other direction ) that will be applied to the ideal surface unit of the reflective material. In such a way the field of forces applied to the ideal surface unit will have a different direction then the vertical. This will change artificially the direction and the intensity of the field of forces that are applied to the surface, resulting in a change of the axis of the catenary ( quasi-parabola). Moreover depending on the intensity and direction of the above forces the catenary may become a perfect parabola like in the case of bridges that are suspended via metal ropes. To obtain the application of the above forces it may be necessary to have the reflective surface formed from many strips to allow the steel wires to pass through in order to by able to change the direction of the parabola. Because the force that is applied to every ideal piece is equal it may be used a unique wire with pulleys. Tracking may be done dynamically during the day ( making use of a motor and software ) or more simply in a fixed way making use of fixed weights ( with the possibility of 3 or 4 changes during the year ). In this case the tracking is "latitude tracking" in order to set the axis of the parabola a little bit lower than the maximum of solar noon in order to maximize the received energy or the produced one with the use of a given budget ( The two solutions are applied in different cases. The first for a direction of the linear parabola from north to south and the second for a direction from east to west).

If for example ( in the case east west ) the direction of the parabola is set to look at 15 degrees lower than the epoch maximum then for 30 degrees of movement of the sun the collection surface will be limited to the extension that the focus has at an angle of 15 degrees.

The duration of 30 degrees may well correspond to the 40% or 50% of the solar energy that may be collected with a parabolic through system that tracks the sun with a rotating parabola.

Similar considerations may be done when instead of having a single piece of parabola we have pieces of different parabolas with the same focus ( set up horizontally ) and a mobile absorber. Similar is also the case when instead of using parabolic forms we make use of many rectangular surfaces set at different angles and regulated to have their focus at a certain line ( for a certain angle of reception of solar radiation). This would be a fixed LFR system ( linear Fresnel reflector). Having fixed surfaces the loss of focus is similar to the parabolic case and we may do the same thoughts ( this was my first approach ). The above systems in all their versions may be constructed in adjacent parallel banks that work collectively and make use of the same supports ( each one with the nearby ) saving one support. The system must be protected peripherally from the wind with walls or other surfaces that may be also flexible but that are able to cut the continuous flow of wind under the reflective surfaces. The instant invention lowers a lot the cost of the field of reception reflection and concentration of solar radiation allowing the construction of very big surfaces with minimal work and materials. For example making use of aluminum rolls we may have a system 40m X 250m with a total surface of 10,000 sq m and 10MW collected radiation with basic cost only the reflective material surface. The above cost could be of the order of magnitude of 100.000 Euro. The efficiency of the system is lower than that of the systems that track ( except for the case were we track using wires - but this has a little bit bigger cost ).

But the cost is much much lower than the degradation of efficiency.

The tracking that uses the wires is also simple and easily applicable while only a motor is requested for the whole system. Another version of the same system based on the principle of using flexible surfaces that isn't much useful for big constructions but for smaller ( experimental auxiliary use - that I had used without understanding it's autonomous existence ) is the use of a horizontal rectangular support frame ( preferably ) for the hanging of the flexible surface with the surface hanged from the opposite sides connecting the absorption system at the center and at the height of the focus line with the possibility of translation of the absorption system along that line. The frame is at a certain height and has the possibility to rotate ( it has wheels and may be rotated by hand or has a motor at it's center in order to be rotated). The system tracks the sun in order to have the lowest line of the parabola to have the direction that have the solar rays when projected on the earth surface. In such a way the solar radiation is concentrated always on the linear focus ( and on it's extension when he sun lowers too much). The absorption system may track the concentrated reflected rays on the focus line having the possibility to get translated along the focus line.

Not to be treated as claims [Claims]

47001 [1] A system formed by a reflector and a receiver. The reflector is formed by a flexible (or formed from inflexible pieces but flexibly connected between them "flexible by strips") reflective surface having preferably rectangular form (any form may work) anchored from two sides with linear horizontal supports (preferably parallel) ( the supports may not be horizontal instead they may decline from north to south if the morphology supports it )

at the same or different height and free from the other two sides having thus it's form modeled by the gravitational force and becoming a linear 3D catenary similar to a linear parabola

concentrating the solar radiation on the second part of the system that is a mobile receiver moving circularly (on the 2D section) with center the bottom of the parabola and tracking the linear focus of the reflected radiation) (figure 2).

47002 [2] Apparatus according to claim 1 where the form of the surface is modeled not only by the gravitational force but also by other forces (applied with wires - cables or by other means) that have as effect to change the direction and intensity of the total force exerted to each ideal piece of the surface in a uniform manner in such a way that the flexible surface reacts as being in a uniform gravitational field with different direction and intensity thus getting the form of a catenary or parabola with a different axis (inclined with respect to the perpendicular). In this way the solar position may be tracked in one direction. If tracking is effected in real time modality then the receiver may also be kept fixed ( or almost fixed ) (figure 47010 [10]).

47003 [3] The system in claim 1 or 2 where the mobile receiver is split into two parts moving in different manner and subject to the conditions of receiving all the reflected radiation while minimizing the total receiving surface. The movement of the receivers is roughly described as done by two arms with one edge fixed at the focus of the parabola while to track the diverging angle the arms grow equally in size and diverge in angle between them (figures 7,8,9).

47004 [4] A system composed from a fixed array of linear parabolic or flat rectangular areas prearranged in such a way as to have the sun rays to pass trough a linear focus (or a limited flat area in the case of flat rectangular areas) given a specific incident angle of parallel rays and a tracking system as described in the previous cases ( single receiver or splitted one) (figure 47011 [11]). In the case of parabolic through surfaces these may have that form or they may get that form from the gravity force of by forces as in claim 2.

47005 [5] Multiple systems of the above claims where each linear reflector is situated nearby the previous one while over each one there is the receiver. In that case the receivers move all together ( or they are fixed and the surfaces move under them ).

47006 [6] The system of claim 1 where the receiver is fixed to be on the focus line of the linear parabolic surface ( and may move along that line for a defined interval ) and the system with the two horizontal linear supports tracks the sun by horizontal rotation in such a way that the concentrated solar reflection is focused always on the linear focus of the linear parabolic surface.

End: Translation of last version accepted by the Greek Office of GR20100100470

Further prior art for solar concentrator.

Prior art that is most relative and "problematic" as to the claims of novelty ( besides what is already cited in GR20100100470 ) is:

US4173397. Solar concentrator 1997/11/30.

This patent makes use of rods extended in parallelism in order to support a tensioned reflective sheet that will get a parabolic or other concentrating configuration ( any form may be created )

Another implementation makes use of bars used as weights that in the case they are of equal weight and equally spaced will give a catenary form. The variation of the weight of the bars may be used to deform the form. This second implementation isn't claimed.

No explanation is given as to how we have to move the collector. A little bit of confusion exists between parabola and catenary and no reference to the similarity between catenary and parabola is made neither seems to be made implicitly. No disclosure of the fact that the sheet alone will get the catenary form without any weight.

US5851309. Directing and concentrating solar energy collectors 1996/04/26.

This patent exploits fully the concept of catenary, by having flexible surfaces with movable ends and fixed receiver. The author knows about the similarity between catenary and parabola and exploits the fact ( but that similarity and the exact behavior or solar rays aren't disclosed ). The patent uses both a static solution and a tracking one on one dimension. Tracking is done by changing the height of the supports of the catenary and it's length. The patent doesn't explain how exactly the concentration changes cause of the sun movement neither which is the way to keep at maximum level the energy reception. Because due to the needs of the patent no concentrated concentration is necessary this may be the reason that such particulars aren't taken care of. Instead the process is resolved in a brute force manner using a microprocessor that by trial and error maximizes the result ( this has advantages too - but doesn't instruct on how to do it without microprocessor - neither gives a deep understanding of the argument ).

This may be the reason too that the catenary configuration is unknown or disregarded.

What is important in the patent is the idea of limiting the radiation in the collector direction by perpendicular reflectors (fig 3A). This was absolutely important due to the small reception field. Besides other the system of vertical or horizontal plane strips of reflectors is exploited (fig 24a and 24b). The strips instead to be absolutely plane can be a little bit curved and in a circular or linear arrangement. Other prior art I know is that of Tho X. Bui in his article: "The solar catenary reflector" published in the make magazine volume 21 January 2010.

This article is actually reachable by: http://www.make-digital.com/make/vol21/?pg=45#pg45 The article doesn't explain too much but it is clear that Tho X. Bui has a complete understanding of the catenary concept and of it's economical advantages. The site of X. Bui is actually reachable by: http://thoxbui.com/catenaryreflector/home.html and explains in a complete manner the whole concept. I kept a hard copy of that site at 2011-08-21 18:06 and it seems to me that the site hasn't changed from when I first saw it in about February 2011.

There is explained too a special solution: the asymmetrical catenary reflector ACRe. The distribution of the radiation is calculated and some solutions explained.

From what has been described it is clear that the "method of using a catenary in order to concentrate radiation" is known and so non patentable. The discovery of catenary properties by me has been independent and unaware of what was previously known so it has leaded to some different results and approaches. I do not know of other prior art so close to what is claimed by GR20100100470 as the previously mentioned material. The above prior art is sufficient to oblige me to defend the claims of GR20100100470 point by point.

Claim 1 of GR20100100470. Here a rotating receiver is devised and nowhere in the above prior art such an arrangement is explained or indicated. The choice of the rotating receiver is a result of the knowledge got by the exact space that the reflected radiation occupies and that is explained by the the geometric demonstration for both the plane Fresnel reflector bank and the catenary reflector.

The description of Tho X. Bui doesn't describe how to move exactly the collector in order to collect the solar radiation. The same is true for US4173397 and US5851309.

Claim 2 of GR20100100470

This arrangement was found nowhere and is a cheap way of keeping concentration high ( at least for a number of degrees ). It is felt that for very big installations may be very important to the cost containment and to have fixed non rotating fields disposed in adjacent banks.

Claim 3 of GR20100100470 has the same reason as the asymmetrical reflector devised by Tho

X. Bui. The solution adopted is different and more complicated than what devised by Tho X. Bui .

Anyway is different and novel with respect to the cited prior art ( but I don't feel that is of great importance).

Claim 4 of GR20100100470 Refers both to Fresnel linear reflectors and parabolic linear reflectors or catenary linear reflectors. At a second thought I will have to divide that claim in different parts because Fresnel linear reflectors have been used a lot and parabolic too. So it may not be impossible to find prior art for them with the described receiver. Any way the flattened catenary reflector ( the exact analog of a parabolic flattened reflector ) should be novel and use full.

Claim 5 of GR20100100470 Refers to a composite system.

Claim 6 that instructs to rotate horizontally the whole catenary MAY SEEM OBVIOUS ( when it has been disclosed - but not before ).

From by personal experience, I con stated that while I have been thinking for months on the argument It wasn't obvious neither for me ( I didn't claimed it right away).

But also for Tho X Bui is not obvious ( according to it's site) because instead of stating it ( the simple solution ) he states in: http://thoxbui.com/catenaryreflector/designs.html

"The basic design for a catenary trough would be a rectangular frame, built sufficiently over-sized so that stray solar rays won't accidentally burn it. It should be tilted so that it faces the sun. It can be rotate to track the sun through the day." So the solution proposed be Tho X Bui is the solution adopted by the Italian patent 1021227 1975/02/07.

But the originality of claim 6 ( with respect to the cited prior art ) is that it isn't necessary at all to tilt the axis of the catenary from the horizontal.

The claim is novel because cause of the fact that catenary reflector techniques are both disregarded and unknown, usually parabolic flexible reflectors are used. So in those

implementations it is possible to rotate along the horizontal longitudinal axis and prior art doesn't implement more then that because there is no need. More over the vertical rotation seems both difficult and of no added value. The rotation along the vertical axis of the whole catenary system at my knowledge hasn't been implemented at all. The catenary has the problem that when not tilted by other means has it's axis perpendicular to the earth. So we cannot rotate it along it's length. Just to state my defensive thought with an example: While it may be obvious that laying horizontally a big linear mirror down and afterwards concentrate the reflected radiation with a parabolic linear mirror that looks upside down, this action isn't so obvious because while obvious in a way, is disregarded by everybody as a "stupid" solution. But in case is proved that this solution isn't so ""stupid" as was generally though and that by using it other problems are solved, that in the specific case ( just to carry it a little bit further the example ) could be the protection of the parabolic reflective surface and of the concentrator system from the weather and dust, and simplification of the cleaning by doing it on a simple plane surface, then the invention of this solution has both novelty and non obviousness because while it was easy to think about the disposition the advantages and uses weren't obvious. On a so worked field as solar concentrators, obviousness is demonstrated by the fact that a so obvious thing has been implemented by somebody. Why should an obvious thing so interesting like that and so simple to implement not be implemented by somebody ?

The only answer is "because it isn't obvious the utility of it".

I think that this it the case of claim 6 of GR20100100470 unless a catenary reflector rotating along a vertical axis is described somewhere or implemented with a certified date before the claimed one ( it may be - but I haven't found it until now - the probable place to search for it is in researches done around 1970 to 1980 inside articles - because I do not have access to that source of material I cannot access it).

When the axis of the catenary isn't tilted the receiver must be translated with respect to the reflector along the focus line by a displacement depending from the elevation angle of the sun. So to avoid to tilt the whole catenary a mobile receiver must be used ( or energy will be lost ).

Figure description

Figure 47001 , shows a reflective surface (47013) hanged from two parallel supports (47011 ) and getting the catenary form. The sun rays have the direction indicated by the arrow (47012) while the focus line is depicted by the dotted line (47014)

Figure 47002, is like 47001 with added a solar energy collector. The collector (47014) may rotate in order to collect the moving line of focus. An hydraulic cylinder with piston moves the collector. Figures 47003,47004,47005,47006,47007,47008,47009 are snapshot of a simulation that shows us how the focus of a parabolic reflector looses it's focus. The angle of incident radiation is measured from the vertical and the direction of incident radiation is shown by the big arrow at the right of the image. So figure 47003 is for 0 degrees, figure 47004 for 10 degrees. In that figure the focus instead of a point becames a small segment and has moved. In figure 47005 the focus grows again and moves more the angle is 20 degrees. In figure 47006 the focus grows and the angle is 30 degrees.

In figure 47007 ( 40 degrees ) we can note that the length of the central segment that collects all the radiation may be exchanged by the two small segments depicted that are of smaller length ( added together ) then the big length. In figure 47008 ( 50 degrees ) the small lines go further away from the central one Figure 47009 is at 60 degrees inclination.

Figure 47010 depicts a catenary reflector tied with strings in order to be able to tilt. The strings that are on the left part of the catenary aren't depicted but must be present. Figure 47011 depicts a fixed array of plane reflectors that when the incident radiation is at an angle of 0 degrees has the focus depicted. If the reflectors are plane then the focus will be a segment of the same dimension as the reflectors while if the reflectors are segments of parabolas or catenaries having as focus the depicted point then the focus will be a point. When the angle of the incident radiation is modified then the behavior is very similar to the parabolic case depicted in figures 47003 to 47009.

Re Description

Here I will explain better the old text, in some parts that seem to be a little bit obscure. Some new disclosure will be made and this will be stated clearly when it happens.

About figure 47010 and 47012 and claim 2 of GR20100100470.

Let's state an example: The whole surface ( say 40m x 100m ) is formed from 25 strips of reflective surface wide 40cm and long 40m. Now we have to incline each hanged strip.

In order to do that we have to apply to the strip a uniform horizontal force ( uniform with respect to the length and weight of the strip - the strip is of uniform weight along it's length). To do that we can attach to the borders of the strip some pulleys where to have a wire pulling. Instead of pulleys that would increase the cost we can attach some U shaped wire that extends past the border of the surface in order to have the wire use it as a pulley. A nylon wire should do the job.

The U shaped attachment must be put on the reflective surface at regular intervals ( say every 40 cm ). So for the whole 40m of the reflective strip there will be 100-1 attachments.

Instead of having independent weights pulling for every 40cm we may use the same wire going back and forth because the tension will be equal along all the wire. If a big number of attachments is selected then the form will approximate very well the catenary at the cost of high number of wires etc. Instead if a very small number of attachments is selected the form of the catenary will be like a "catenary polygon" ( Such form of "catenary polygon" may be desirable when we need distributed concentration as in the case of photo voltaic cells). So the optimal number of attachments is something to find in the real field and that depends on the flexibility of the material used. Instead of a U shaped attachment for each strip of reflective surface, we can connect adjacent strips that are kept at a distance ( say 10cm ) to leave the wind pass through, with some kind of rods and use the rod as a pulley passing through it a nylon wire.

When there are parallel banks of catenaries then the same wire may serve to pull the same point in the catenaries in all catenaries passing along all the banks of catenaries. In that case an initial tensioning and fixing of the position of the wire should be done.

By pulling that wire we act on all catenaries ( on the same point in the shape of the catenary ). It may seem too much complicated to install all those wires and pulleys in order to have the catenary track the sun. So the system may seem useless in practice.

But a single person is able to install a so described system of an aperture of 40m while it would be completely impossible for a single person to install a fixed parabola of 40m wide and to rotate it. While the catenary tilts and it's axis gets rotated, the line of focus moves a little bit. The catenary becomes narrower and it's focus goes lower ( figure 10). To understand what happens get a rod keep it horizontally and attach at it's ends a chain. Make the chain so long as to have the focus of the catenary on the rod. By reference to figure 1 the rod is the horizontal segment AB and the catenary the part of the drawn catenary that goes from A to B. This means that where the chain is attached the inclination of the chain with respect to the rod is 45 degrees. Now rotate the rod a little bit ( say 10 degrees ) using as axis a horizontal line vertical to the rod . Now change direction and look that system with the head tilted by 10 degrees. So now the rod seems horizontal. What has happened ? .

Looking at figure 1 and supposing the rod AB has become CD we can note that CD is longer than AB so in order to have the same physical situation ( that has as a condition that the length of the rod is constant ) we must make the image smaller. Besides the image must be made smaller also due to the fact that catenary segment CD with respect to catenary segment AB differ by the difference between catenary segments AC and BD. So because catenary segment AC is smaller than catenary segment BD, catenary segment CD is longer than catenary segment AB.

By looking catenary segment CD we note that the focus has moved moving on the rod to the left. But the image must be made smaller. Now we have to see if the ratio of change of length of AB related to CD is more or less then the change in catenary length of catenary segment AB related to catenary segment CD. The answer the the above question will determine if the second condition ( catenary length constant - independent from rod length constant ) so if finally the focus goes up or down or doesn't move.

By calculation with a spreadsheet it has been calculated that the change of the ratio of the length of the catenary to the length of the rod has the subsequent values for the given angle of inclination according to figure 10. What is exactly calculated is the ratio between the length of the catenary and the length of the rod in figure 10 while rotating the rod. It must be understood that in order to have the same physical situation the resulting image must be reduced. What is calculated is if that reduction get's us to the same factor between length of rod ( physically fixed ) and length of reflective surface ( physically fixed too). In order to be happy we'd have to have that ratio constant. But it isn't like that .

0 5 10 12 14 16 18 20 22 24 26 28 30 40 50 60 70 80 1 ,000 0,999 0,996 0,994 0,991 0,989 0,986 0,983 0,979 0,975 0,971 0,967 0,962 0,936 0,905 0,873 0,840 0,808

That means that in order to keep the the focus on the rod the length of the catenary must be diminished by the above factor for each different incident angle. If not the length of the catenary being bigger the rod should leave the focus and go upper to get more catenary length. That means that with respect to the rod the focus lowers. It is felt that inclinations above 45 degrees are very difficult to track with a tilting catenary. Small variations of the length of the catenary under 3% are to be neglected while over 28 degrees the catenary could be adjusted a little bit by rolling the reflector ( or just rolling some wires that are attached to the supports supporting the reflective surface). What seems valid is that the rotating receiver tracks very well the focus because goes as half the angle and lowers. So no adjustment of the focus by rolling and unrolling is necessary at all. The above argument needs some more simulation.

New Disclosures About claim 6 of GR20100100470 by using the underlying ideas contained in patent US5851309 Directing and concentrating solar energy collectors 1996/04/26 we can modify our horizontal rotating catenary reflector by eliminating the translational capability of the receiver, fixing it, and adding to the system a vertical reflector at the end that the reflected solar rays go away. The solution described in order to eliminate the translational movement of the receiver is neither claimed neither disclosed in the above patent.

End>

In order to avoid to use surfaces of excessive weight in order to alleviate the wind effect, by using the example of a surface of 40m wide X 100m long we may use narrow strips of 0,40cm each and long 40m ( 250 to make 100m ) and interleave between the surfaces from 10cm to 30cm in order to let the wind flow between the surfaces without pressing them too much. The surfaces may connect between them along the length line with some elastic material or wire in order to have a resistance to local variation of wind.

If that connection is continuous from the start to the end of the catenary and a non tilting catenary is constructed then that line of connection may be kept tensioned by attaching the first and last wire or connection to a fixed support of catenary form that is disposed at the start and end of the linear catenary. So a tension along the length of the catenary will keep resistance to the wind.

At the same way when a not tilting catenary is used besides fixing it's two sides it's bottom line

( the point of the catenary where x=0,y=0 ) may be fixed in order to limit the wind effect.

This fixing may be done by a support along that line but also by sandwiching the surface between two stainless steel wires tensioned at the start and end of the catenary.

The whole catenary may be constructed by the use of steel wires ( figure 20)

Just as an example to show the idea: Two metallic "T" (201 ) with width 4m and height 1 m are used. Only the upper line of the T is used. The upper line will be used to connect the 3 long wires

(204) . The central one will support the collector system (202), while the other two the hanged reflective surface (203) ( in strips ). The vertical part of the T is necessary only to put a weight

(205) in order to keep the T vertically aligned. Connected the two T with the 3 long wires ( in figure 20 only half of the construction is shown) ( the wires have about the length of the catenary through 40m ).

Now we can attach the holding wire (206) to the T to the top center from the opposite side from where were attached the 3 wires. Doing the same to the other T we have two holding wires and by them the system may be tensioned. Once tensioned we can put on it the reflectors and the receiver. The holding wires may be translated on two parallel guides (200) distant a little bit more the the length of the catenary ( at least the length of the diagonal of the catenary through). These parallel guides should have preferably an east west direction. So at solar noon when the catenary would be perpendicular to the supports and the sun would be focused on the collector.

The length of at least one of the two holding wires (206) is variable and connected to an automatic tensioner (207) and so the system may be rotated under steady tension from a specified maximum angle e.g. -45 to 0 to 45 degrees in order to track the sun. Many systems disposed in parallelism ( figure 3 ) and having at least a distance from left side to left side of width_of_T/cos(maximum_angle) so in our case about 5,65m are able to rotate from -45 to 45 degrees tracking all together the sun. Cause of the catenary form assumed by the tree long wires the resulting system isn't exactly a linear catenary through as described before. Instead is a catenary catenary through. But because the catenary formed by the three wires is wide and the tree catenaries are of the same dimension the concentration isn't affected by the deformation of the system. The installation work on the field is only on the two sides of the catenary to put the two parallel supports that serve the translating of the holding wires . It must be noted that because the lateral long wires that hold the reflective surface may be pulled but the weight of the reflective surfaces towards the central wire, it may be necessary to put between the two lateral wires at constant intervals spacing rods in order to keep that wires at constant horizontal distance. A variation to the above system that tries to keep the height of the whole system low while being able to have a huge width is the solution that cuts the catenary into pieces, like a Fresnel catenary through. The section ( along the length ) of such a system is as described

( bidimensional image )

At first we set where we want the focus to be ( e.g. on a cartesian plot X=0 Y=Y0) . Then we create the central catenary segment AB ( the half of it ) that has that focus (figure 47030). That catenary segment has Y=0 when X=0. We draw a line from the focus to the symmetrical two ends of that catenary segment. Suppose that line intersects the X axis at (+/-)X1 ( that point is a little bit displaced from the end of the catenary segment). We draw a catenary segment (CD) that has as focus the predefined focus and that starts from point X=X1 , Y=0. That segment is just a

magnification of the continuation of the previous catenary segment. In order to define the length of the segment, it is better to set as a condition for that segment to have a predefined length ( equal for all segments ).

So all the pieces will be equal. Bu calculating the X length of the segment ant the final height the process of forming the requested catenary from the reflective surface is just to append the specific length of material to the specific two ends. Also that whole system may be created by wires with some modifications and so the rotating flattened catenary may have a big width while protected from the wind effects cause of it's limited height.

By the rotation of it all the radiation received by the area covered by the receiver is reflected to the line of focus. In some constructions it may be necessary to use towed cables, but any particulars of the implementation is well known art, so it isn't of interest to disclose further.

This keeps the installation costs low and dependent on the perimeter of the system instead of it's surface.

It isn't felt that complicating the system to go over indicatively 45 degrees will give any significant energy advantage to the system while it will complicate things by making the holding wires too long and over tensioned. The above description isn't technically accurate and the figures are very rough and inaccurate, but are meant to give the main idea of how to make the system. Many variations are possible and or desirable but aren't the essence of the subject.

Here ends the description of the collector part of the application.

The solar rays are concentrated on a collector and we may use various solutions to use the concentrated radiation:

a) We may use cooled photo-voltaic cells ( also by using special photo voltaic cells ). b) Collect the energy via evacuated tube system and a heat transfer liquid and a heat circuit. In the heat process such energy must be consumed at a rate that maximizes thermodynamic efficiency by taking into account the black body radiation, thermal losses, and the optimum temperature related to the Carnot efficiency. So the heat transfer liquid must circulate at a rate capable of transferring the consumed heat without big drops in temperature. By using a heat transfer liquid the heat may be captured also for later use by using heat deposits.

Such heat may be used later in a steam engine, a steam turbine, or a Stirling Ericsson or similar type of thermal engine.

c) Instead of that the energy may be consumed directly at the collector by making it the hot part of a thermal engine ( Stirling or Ericsson or other type). In that case energy will be generated on board ( on the receiver ) and energy will be transferred by hydraulic or electrical means.

d) The collector may contain a steam generator and steam may be directed to a steam engine or turbine.

Besides the photo-voltaic solution, the solution we opt especially for is the use of a Stirling type or Ericsson type of heat engine instead of using bulky and non scalable steam turbines.

Here the decision is dictated from the strategic choice to be able to make small and medium installations that may be scalable and constructed with simple materials that may be provided locally also in underdeveloped countries without the need of high or too precise technology. While the working principles of such type of engines are well known and fully disclosed, I think that some important parts of them are not understood and this has the direct result that such engines are generally of low efficiency and/or work only with great temperature differential. By choosing such a type of engine instead of a steam turbine, we must resolve any such inefficiencies in a manner that renders our solution as efficient as a steam turbine.

Besides that the problem of energy accumulation, is resolved also by compressed air deposits. While it may not appear immediately, a thermal engine may be constructed by an efficient "isothermal compressor" that compresses air at ambient temperature and accumulates it into a deposit while expels the generated heat into the external ambient and by an efficient "isothermal expander" ( compressed air motor ) that expands hot air while gets high temperature heat from a hot source. In order to convert the cold compressed air into hot compressed air and the hot expanded air into cold expanded air a re-generator is used between the cold compressed air entering the expander and the hot expanded air leaving the expander.

So the cycle closes and leaves a net surplus of mechanical energy. The expander part of the system may be used also as a compressed air UPS and more generally as a power generating unit ( if a generator is coupled to the expander ). Obviously such and expander may also be used as a compressed air engine to be used in compressed air cars. So the invention itself scatters into more fields and an efficient solution would have many use full applications.

The argument of efficient compressor and efficient motor have already been analyzed in the application GR20100100533 a revised text of it is bellow

Start of revised description of GR20100100533

Motivation and needs Cylinders and pistons are known from centuries ago and it doesn't seem that we can do any important improvements. I will narrate the background and the needs that drove me here in order to explain the reasons that obliged me to opt for the instant solution but also to explain it's importance. In order to construct an Ericsson cycle engine ( something like a Stirling engine) for the generation of mechanical work from the transport of heat from high to lower temperature, I separated the subsequent steps ( this is full prior art nothing new):

a) Compression of a fluid ( air ) expelling the generated heat to the low temperature heat deposit. During the compression we give mechanical energy ( in the case of a perfect gas we don't have any change in the gas internal energy and so all the mechanical energy is converted to heat). b) Use of a re generator to change the temperature of the compressed fluid to a higher one ( in connection with step d ).

c) Decompression of the above fluid maintaining it's temperature high using heat from the high temperature deposit.

d) Use of the re generator to lower the temperature of the fluid ( steps b and d may be replaced with adiabatic compressions or expansions). We want to use the above engine when we have a low temperature of T1 =300 K ( degrees Kelvin) and a high temperature of T2=450 K ( degrees Kelvin ). ( Roughly 30C and 180C ). Cause of the thermodynamic theory the maximum efficiency that could have such a thermodynamic engine is (T2-T1 )/T2 ( 33% ).

In our example the compression of the fluid ( step a) starts from an initial volume and pressure and sub multiple of the initial volume and a same multiple of the initial pressure ( assumption of a perfect gas behavior ). During the compression we give mechanical energy. When the fluid changes temperature if this happens isochorically ( at constant volume ) then it's pressure changes by a ratio T2/T1 ( case P*V=n*R*T). So all the process of the decompression will give us exactly the energy that we gave during the compression multiplied by the ratio (T2/T1 ).

So we give a mechanical energy E and we get a mechanical energy E*(T2/T1 ). Obviously we have also thermal energy that takes part in the process so we have the conservation of energy but this doesn't interest us now. Conversely when in the process we have losses the plan changes: In our previous example if we give energy 100 and we loose 20% then at the end we will have a compressed fluid with "stored energy" 80 ( at that temperature ).

When we change the temperature of the fluid from 300K to 450K then if the decompression happens isothermally at the final temperature will give us the initial energy multiplied with 450/300 and so will give us 80*(450/300)=120. If we decompress the fluid with efficiency 80% then we will have a mechanical energy output of 120*80%=96. So we gave initially 100 units of mechanical energy and we got finally 96. So our engine doesn't work, the movement isn't auto generated, and we cannot get surplus energy from the process for any other use. Especially when we have low temperature differences ( E.g. geothermal source of heat ) to have an engine that works and that is able to give back energy is very important to eliminate the losses to a minimum.

I checked personally the efficiency of various commercial motors and the results are

disappointing. Table 1 shows some data that refer to various air motors and turbine motors ( the table has been constructed with the data that the constructors have furnished). An exception may be done for the Di Pietro Air motor ( US Patent 6868822 ) ( this motor is used in air pro pulsed vehicles ). Under certain circumstances the above motor is very efficient ( but not under all circumstances ). The reason for the disappointing data are determined by two factors: a) The effect of friction that is proportional to the square of the speed and begins to matter at high rpm . b) The limited heat flow from the ambient due to the low surface of contact of the fluid with the cylinder and the piston and so with the ambient. So the instant invention had to solve the above two problems. The thought went at first to a very short and very large cylinder. So the surface of contact of the fluid with the containing vessel would be high. Afterwards I had to eliminate friction. So I went to tie the periphery of the cylinder and the piston making use of the elasticity of the materials to get the movement without friction. Eliminating the friction there is no need for lubricant ( that may create problems at high temperatures). We eliminated also leaks because everything is hermetically sealed.

Implementation

So the instant invention replaces the cylinder and the piston with two preferably subtle preferably circular plane metallic surfaces (1) that are set each on top of the other without leaving space between them and these are sealed hermetically at their periphery.

At the center of the surfaces there is a reinforcement and attachment (2) for a connecting rod (3) from where the forces will be transferred ( figure 53302 [2] ). The remaining parts of the engine where this system of cylinder-piston belongs remain the same ( input output connections, valves, spark plug, and what else).

Another implementation is that of figure 53303 [3] where we have rectangular surfaces (1 ) with a circular finishing, reinforcement and attachment (2) for a connecting rod (3) that in that case is a vertical blade. The invention doesn't depend on it's shape ( if the surface will be circular, elliptical, rectangular, or of another shape) neither on how many input outputs will have, neither on how exactly will be shaped the subtle surface in order to suffer the repeated deformations during it's function. These are implementation details, that need long term checks and

experiments inside a factory. The basic characteristic of the instant invention is that we make use of two opposed metallic surfaces that have an input output that are sealed hermetically at their periphery where the inside volume is zero at minimal volume state. Getting in ( or expanding ) inside the system a fluid under pressure the two surfaces due to their elasticity change and deform and via attachments that are in the symmetry region ( the symmetry region may be a point or a line - depending on the shape of the surface) we may transfer the forces of expansion or compression of the fluid and so the energy of the physical process may be transferred.

The volume changes from almost null until a certain value avoiding the friction but remaining in the elastic region of the material in order to avoid a permanent deformation.

Obviously the metallic surface being a good conductor of heat, transfers the thermal energy of the phenomenon that is important too.

Previous state of art

There is similarity with membrane compressors and pumps which make use of a soft elastic membrane inside a fixed volume space divided in two regions by the membrane and where the volume of the two regions is modified by the reciprocation of the membrane ( figure 53304 [4]). Some times membrane pumps use also a metallic membrane. In this case the membrane has only the function of separation while the forces are transferred from a working liquid.

Conversely the instant invention makes use of hard material that according to the usual model is rigid and the system has a null volume when it is in the state of minimal volume.

Moreover there is only one volume. The forces are transferred using the same material making use of an attachment that is on the plate and using the hardness of the plate.

The rod works both for compression and decompression ( so in compression and tension of the material ). Like a part of a thermodynamic machine have been used ( Stirling type motor ) rubber surfaces with metallic center for the same reasons of the instant invention ( figure 7 A. Der Minassians and S. R. Sanders, "Multi- Phase Stirling Engines ", 6th International Energy

Conversion Engineering Conference and Exhibit (IECEC), July 28-30, 2008)

(see also : http://www.redrok.eom/engine.htm#rubber. The Rubber Engine Project. Brayton piston engine generator. I have experimented with a form of piston engine suggested to me by Gene Townsend called a rubber diaphragm piston Brayton engine. This rubber engine essentially is built from flat cone of silicon rubber backed by a shaped metal plate. This type of piston is completely sealed, a very desirable quality. I haven't had enough time to work on this engine to completion so I can't report on the how well it works. Gene suggests this construction technique would work better as a steam Rankine engine. )

When the material is very elastic ( rubber nylon ) it works well only in tension and not in compression. Moreover an elastic material cannot support big forces as may suffer and transfer the metal. So when we use an elastic material we need to introduce also a metallic part having so a more complex system with more failure points. The elastic material gives us the easy solution because it deforms a lot having as a result to have a big reciprocation, while we cannot see immediately how much may be deformed a metallic material ( ideally the mean person thinks that a metallic material is in deformable using usual forces - but the forces of compressed fluids aren't usual ). Using a metallic surface we have smaller deformations and so a more complex mechanical construction. But when instead of using a connecting rod and a crankshaft we make use of a free piston then the entity of the deformation looses it's importance and the problem is over. Maybe this is the reason that this technique hasn't been used ( according to what I am able to know actually ) until now. But the elastic material ( rubber or so ) lacks a very important property of metals: the thermal conductivity that is crucial to the correct function of thermodynamic cycles where there is transport of heat ( non adiabatic cycles ). The metal offers us the transport of the heat that is substantial to any thermodynamic cycle. The use of all the surface of the piston as a thermal conductor may make the difference between an efficient and an inefficient thermal engine. That capability of thermal conduction is exacerbated in the linear model of piston that uses rectangular plates, because the ratio between surface and volume is bigger then that of the circular case. The linear model multiplies the capacity of thermal transport up to the point that is necessary for each case. Non metallic material has an other shortcoming: It doesn't support high temperatures. So it isn't adaptable to a Diesel engine etc. So the metallic choice is the only choice for engines where high temperatures are involved.

Problems that are resolved by the instant invention

The problems solved by the instant invention are the lubrication, the compression losses, the fluid leaks, the friction, and the maximization of the surface of heat transport from and to the outside.

When a motor makes use of the usual cylinder and piston cause of the rings there is friction especially at high speeds. Cause of the friction there is need for a lubrication system to mitigate the friction. But the lubrication may be a source of inefficiencies cause of the limits that imposes on temperatures and on the need to cool the lubricant.

Friction and losses of compression or leaks are contrary each to the other.

To defeat the losses and leaks the piston and the rings must be in hard contact with the cylinder, but if the contact is tight the friction is high. On the contrary if the contact is loose there may be losses and leaks. The instant invention abolishes the friction because there aren't zones that generate friction. The system changes volume making use of the elasticity of the materials and we pay attention to keep it between the elastic limits of the materials in order to avoid any permanent deformation, loss of energy, and in the long run destruction of the material.

This means at least theoretically that the piston may arrive at very high speeds without having it's efficiency diminished by friction ( Another source of friction will be especially at very high rpm

( above 10000 rpm ) will be the generated sound. That effect may be eliminated by using air evacuated engines ). Another problem that is resolved is peculiar to air motors and to

compressors. When a fluid is compressed or expanded it is necessary to have a big surface to transfer the heat of the process. Such a big contact surface of the piston and the cylinder with the inside fluid may be obtained only with great modifications to a usual cylinder-piston.

The inability to transfer the necessary heat of the process has direct negative impact on the efficiency of the air-motor or compressor.

Practical aspects

While theoretically it may seem that such a system could work there are practical questions: a) How much will reciprocate the system under a certain pressure ?

b) At which pressure the system goes over the elastic limit and starts to deform permanently arriving finally to crack and break ?

c) What is the exact shape that it must have especially at the periphery and at the center that are the more forced regions ?

With some calculations that refer to the characteristics of various materials it seems that the maximum reciprocation for a plate of 30cm of diameter could be about 1 cm or 2cm without suffering from a permanent deformation table 2.

With some finite element analysis calculations done on a PC, have been checked the regions that suffer most and has been devised a shape that seems to work acceptably. ( thicker at the periphery and at the center ) figure 53305 [5].

The material may be steel or titanium or special aluminum alloys.

The material must have a great ratio of elongation to tension until the limit of elastic deformation.

Various materials with their characteristics are considered in the table of material choice table 2. To obtain the same results the surfaces may be also of other shape like rectangular and their shape not exactly plane but modulated in order to support the deformation especially at the periphery.

Various implementations of the system

a) A rough implementation (figure 53302 [2]) of the system may be constructed from two plane subtle equal metallic surfaces (1 ). The system of the two surfaces (1 ) must have a input-output (14) for the transfer of the working fluid ( it may have separate input and output ).

In the center of the two surfaces there is an reinforced attachment for the connective rod.

b) Another implementation of the system may be constructed from two subtle surfaces with a specially shaped surface that is able to support the deformations that happens during the work cycle figure 53305 [5].

c) Another implementation of the system (figure 53303 [3]) may be constructed from two subtle rectangular surfaces (1 ). In this case in the center of the two surfaces there is a blade for the force transport (3) (connecting rod).

d) In another implementation the system may be constructed from a subtle surface and a thicker one that we will call base and that cause of the thickness only the subtle surface will have a noticeable deformation and reciprocation figure 53307 [7].

In that case we diminish the reciprocation to the half of the previous cases.

e) Another implementation of the system may be constructed with many pairs of case a b c or d that will have a common input output and their volumes will communicate so that a fluid entering from the common input will be distributed in all pairs figure 53306 [6].

f) We can have also a thick base with two subtle surfaces from both sides. The result is depicted in figure 53308 [8]. In that case the base may be a base for other functions ( it may have the input output valves etc). The present invention is simple to construct and may be used as part of a Diesel engine, a gasoline engine, a compressor, a pump, an air motor, and as part of a Brayton or Stirling motor, and also in other uses. What has been described so far is sufficient to allow a person knowledgeable in the field to construct the invention.

While it should be sufficiently clear how to use the above system in existing engines or for the construction of new ones I will describe the use of the system in classical cases.

This is to show the utility of the system in specific cases and to give ideas of uses that I do not know.

Construction of an air motor using the invention

Let's take a reciprocating air motor that makes use of cylinders and pistons. Substituting the cylinder-piston with our system we have two surfaces each on the other without volume between them and tied to a solid system that seems in deformable.

In figure 53301 [1] the compressed air starts from the deposit of compressed air (10) using the input pipe (11 ) enters the timed entrance valve (13) which may be a rotary one, an

electromechanical one or whatever. Using a flexible tube (14) the compressed air enters between the two plates (1 ).

Applies forces to the plates that have an order of magnitude of tones and so that great forces bend the flat system. This movement transports the force and so the energy of the physical process of expansion. The movement is transported via the connecting rod (3) to the crankshaft (20) that rotates. This is exactly the opposite of what is happening in truck leaf springs. In truck leaf springs the spring is flattened by the force of the weight of the truck ( inside the elastic limits ). When the plates arrive to the maximum deformation that is defined from the point of attachment of the connecting rod to the crankshaft (21 ) then the timed valve (13) connects the passage (14) with the exit (12) and the system decompresses and returns to the flat state while the crankshaft (2) continues to rotate.

We have so an oil-free engine because there is no need for lubrication.

We do not have any friction during the deformation of the system under the condition to stay under the elastic limit of the materials (avoiding so a permanent deformation).

We don't have any leaks because the system is hermetically closed from the outside world and connects to it only via the valves.

The system of the instant invention is especially suitable for the construction of a motor that during its cycle needs to expel or receive heat from the outside world ( a Brayton or Stirling engine, a vehicle air motor, a compressor, an general use air motor etc ).

When we need to transfer heat to or from the outside world the external surface of the plates may be modified like the surface of a compressor cylinder in order to augment the heat transfer capacity, or the system may be in contact with a heat transfer fluid.

Moreover we may extend ( figures 53309 [9], 53310 [10]) the circular surfaces after the point of seal (16) in order to put on that extensions cooling or heating elements (15). In that figures we see the plates (1 ) the point the sealing point (16) and the section of heating cooling tubes (15) that are circularly placed on the plates and allow the circulation of the heat transfer fluid.

The reciprocating air motors ( or air expanders ) have two valves one for the input of the compressed air and one for the output or a unified one (13). The valves may be controlled electronically or mechanical or instead of valves there may exist a rotative air switch that is controlled from the crankshaft. At the beginning of the first cycle the input valve gets opened and in the ideal case stays open until the ratio between the volume of the compressed air that gets into the cylinder and the maximum volume is the same with the ratio between input pressure and desired output pressure. Supposing that we have an isothermal expansion the final exit pressure will be the same as the desired pressure ( that will be usually set to the atmospheric one).

In that case we do not have losses due to the exit of air to a pressure greater than the

atmospheric one. If we need more power then we may input more compressed air but in that case we will have a loss of efficiency. When the expansion cycle completes then with the beginning of the second cycle the output valve opens and the air is released outside. At the end of the second cycle the output valve closes and the input valve opens cause of the start of the first cycle.

Construction of a compressor

To construct a compressor we take the air motor of the previous case and we work it in the inverse manner. If the valve is a rotative switch then the system works immediately.

If there are valves controlled from the crankshaft if we want we may simplify the system replacing the valves with check valves ( with opposite direction each to the other ).

When the crankshaft is rotated it will create a reciprocating force via the connecting rod and we will have an air suction and afterwards a quasi isothermal compression ( cause of the big surface of contact of the cylpiston with the contained fluid). The compressor is also a pump. For the cooling elements is valid what has been said for the compressor.

Construction of a Diesel Engine

To construct a Diesel engine with the instant invention we need two valves exactly like in a usual Diesel engine, with the same elements and timings.

Obviously we can also use rotary valves (for example: U.S. Patent 4,944,261 , issued July 31 , 1990 "Spherical Rotary Valve Assembly for an Internal Combustion Engine").

The input valve inputs the fuel-air mixture and that enters the chamber by suction at the start of the first cycle. At the start of the second cycle the input valve closes and compression starts. By putting the crankshaft at the required distance the system arrives to a minimal non null volume ( that has been defined by the regulation of the reciprocation of the crankshaft and the distance of it from the cylpiston ) so the fuel ignites. After the ignition starts the third cycle where we get the energy of the phenomenon and when the cycle finishes the fourth cycle starts with the opening of the output valve. When the fourth cycle completes the output valve gets closed and starting the first cycle the input valve opens to let the fuel mixture enter the chamber. The expansion in that case will be adiabatic. When the expansion is adiabatic the big surface of contact isn't necessary so here the use of the invention may be useful only for the possibility of rotating at very high speed cause of the lack of friction.

Construction of gasoline engine

If we need a gasoline motor using the previous engine there will be on the plates one more hole for the spark plug that will be timed accordingly.

Construction of an external combustion engine.

Four stroke engines have a loss of power related to their weight cause of the 4 cycles that are used. Two stroke motors have problems with the purity of the cycle and the mixture of fuel mixture and combustion gases. A lighter engine may be constructed using only two cycles and having an outer combustion chamber ( one for all cylinders).

The combustion happens in the external chamber in controllable and continuous manner in order to keep a specified pressure in that chamber. So we generate compressed combustion gases in an outer combustion chamber. Afterwards we use the air motor to create motion.

As a difference with the compressed air motor we must say that cause of the high temperature of the combustion gases and laking a high temperature heat reservoir the expansion is adiabatic and not isothermal. This is a kind of Brayton motor.

Construction of an electro compressor.

The compressor that we mentioned in a previous paragraph instead of working with a connecting rod and a rotating electrical motor, may reciprocate by making use of an electrical coil a permanent magnet and alternating current. Similar kind of compressors already exist and make use of a diaphragm. The counter indication for the use of diaphragm is the low pressure that may be obtained.

Construction of a compressed air electrical generator

The air motor that we described previously instead of making use of a connecting rod and be connected to an alternator, may reciprocate a permanent magnet inside a coil ( or reciprocate a permanent magnet inside the cut of a toroidal solenoid ) that will generate alternating current ( and current if there is a circuit ). I do not know of electrical generators that use compressed air as the propulsive force ( at least commercially available now ).

For static applications where volume and weight isn't a problem compressed air is a very viable energy storage medium at a very affordable price. A so simple electrical generator may push on the use of compressed air energy storage.

Construction of an engine with variable crankshaft eccentricity The cylpiston has a null volume and a maximum volume that is imposed from the characteristics of the material that constitutes the plates and the safety factor that we want to keep. Using a crankshaft with the capability to variate the eccentricity, and distance between the center of the crankshaft and the cylpiston by the same amount we may have an engine that works always at the maximum efficiency independently of the input pressure and load applied.

Variations

The base of the construction of the cylpiston is the surface of the material that contains the pressure of the fluid and the use of the material elasticity to get and transfer the forces.

Getting two such surfaces we create a cylpiston.

We may apply various modifications based on the same line of thought:

a) We may use surfaces that aren't plane in the internal surface but are one specular respect to the other so that the internal volume is null when minimum but there exists a bigger surface for the transfer of heat to and from the outside.

b) We may make use of surfaces that have external nerves for the transfer of forces from the periphery to the center.

c) We can add lamina to the external surface in order to transfer faster the heat.

d) We can modulate the thickness of the plate from the periphery to the center in order to obtain the maximum durability ( minimal material stress ).

e) We can design the plate ( or the surface if it isn't circular ) in order to have at rest a bended form between the minimal and maximum volume. With this technique the plate ( or surface ) will work in both compression and tension and will have a doubled reciprocation or using the same reciprocation create less stress on the material having so more longevity.

f) We may design the surfaces to be rectangular instead of circular, in that case we will have a force that will be got along the material length using a blade ( instead of connecting rod). The rectangular case augments the surface of contact in relation to the volume of the fluid but creates some engineering problems on the small sides of the cylpiston.

g) We may use more cylpistons each on top of the other with the lower hole of the first communicating hermetically with the upper hole of the lower one constructing so a multi cylpiston. We may use for input output the lower hole of the lowest cylpiston (while the upper hole of the upper cylpiston is closed) or use as input the lower hole of the lower piston and as output the upper hole of the upper piston. So the reciprocation will be multiplied. Conversely using two surfaces of different thickness a thicker one and a thin one the tick one will stay almost undeformed so the cylpiston will have half the reciprocation of a normal one.

Conclusions

The invention is simple to construct, has no wearing parts ( if the right engineering is done and the elastic limits are respected) and simplifies the construction of air engines, Stirling engines, Brayton engines, simple air compressors etc.

A very big engine may be constructed with the above techniques in a cheap and fast way.

Suppose for example we construct an engine of diameter 1 m. Then the area of the plates will be roughly 1sqm. By using compressed air at 10 bar the volume inside the engine will be the volume of a cone so 1/3*area*height. Supposing to have an elongation of 2cm from each side of the plates we have a total elongation of 4cm. The work done at each expansion is proportional to Ln(Pr)*P*V ( where Pr is the pressure ratio from input to output. Let's suppose that ln(Pr)=2). So the P*V is about 2*(1/10(m^A3))*10*Bar= 200.000N/m^A2 * m^A3 = 200.000J.

Having the engine working at 10Hz so at 600 rpm then the power is 2.000.000 W. So 2600 Hp. Like a train locomotive. Not bad at all.

It may not be impossible to have the engine working at 3000 rpm that means at 50Hz so in that case the power will be 10.000.000 W that is 10MW.

End of revised description of GR20100100533

More prior art

Prior Art for GR20100100533:

Some prior art has been found on some versions of GR20100100533.

US2611236: The need for the design of the engine described in the above patent are exactly the same needs that I had. The difference is only in the kind of starting point. The above mentioned patent starts from something that is ready "the bellow" and that is designed to be compressed and expanded. While the GR20100100533 starts from something that isn't designed for such a work. GR20100100533 extends the design to a bellow type but this is not the main part. The form of bellows is different because in the case of GR20100100533 the central hole is very small because we need to use the maximum surface in order to expand efficiently ( using the surface for heat transmission). Moreover the minimum internal volume in GR20100100533 should be ideally zero - as stated in the application - and this can be accomplished only by having a very small hole at the center.

It isn't so clear if US2611236 covers as prior art GR20100100533 due to the differences both of start point and design. There is also another patent ( that I lost it's number ) that has a bellow inside another bellow. Other prior art is US4122756: Here it is clear that this kind of bellow is totally different of that of GR20100100533 . Also US4170166: Here too the bellows have a different use. US3974744 is another different implementation. US4179893 describes a "bellows solar engine". Anyway it is felt that "bellow" type of construction isn't of great importance too for the same reasons that the main design of GR20100100533 has proved to be not very efficient if not flawed.

Problems of application 2010100533 and related solutions

Application 2010100533 tries to resolve some problems of reciprocating engines. The main characteristic is the great surface of contact of the compressed or expanded fluid with the "outside world", the absence of friction lubrication and the use of material elasticity to avoid friction. During the application some problems arise and modifications are necessary.

The essential problem is that the mechanical application of force at the center of the surface creates a depression in that point having as result to have a non null internal volume despite of the fact that the rod is completely pressed. Using as a paradigm a circular cyl-piston then around the central point we have a torroidal swell a torroidal inflated zone that contains fluid wherein the internal volume should be null. This defect ( that is present both during expansion and

compression, but it is easier to uderstand it thinking of the compession phase ) diminishes the efficiency of the system by leaving dead spaces. Two different solutions arise to resolve the problem: The first one is to stay within the initial design trying to resolve the problem.

In that case we have the subsequent solutions:

a) Change the construction of plates in order to have them to bend spherically in only one direction and not in the other. This may be effected by attachment or inclusion ( by melting ) into the internal part of the plate of carbon fibers disposed radially. Carbon fibers must have their direction of resistance to tension along the diameter of the plate.

This use of carbon fibers creates the asymmetrical elasticity of the plate.

So (figure 4) when the plate (400) gets inflated the fibers (401 ) do not generate resistance, instead when the surface is inflated and gets pressed at it's center the center would have the tendency to go bellow the rest of the surface, but cause of the thickness of the plate this would elongate the fibers. Cause of the resistance of the fibers the surface is obliged to depress all together. In case the system is linear ( an elongated paralellogram (402) ) then the construction is simpler and carbon fibers are disposed only in one direction perpendicular to the length of the system.

b) Instead of carbon fibers we could make thicker the surface and cut that thickness on the external surface up to a predetermined depth along circular concentric paths for the circular case or along the length of the system for the linear case in order to let the surface to bend

assymetrically ( figure 5 ).

c) Instead to use a single surface we may use the system described in figure 53306. In the circular case we have many circular plates with a small hole into their center. We put the first plate and over it another one. We weld the two plates at their periphery ( e.g. using laser welding ). We put over another plate and we weld it to the previous around the hole. We put another one and weld it with the previous one around the periphery etc.

At the end there is a bellow where the torroidal inflated zone disappears because each plate presses the adjacent one and the torroidal inflated zone is depressed. We continue to have the problem in the upper and lower part that is percentually much lower ( and we can put there thick plane plates ). Any way there are serious losses due to the friction and crashing ( and noise) between torroidal inflated zones when the bellows are compressed. The construction described may be created also in a linear arrangement.

d) We may use only one flexible surface ( and a thicker one bellow ).

When we put the rod in the position of minimal volume, and we have choosen the thickness of the plate, then we inflate the system to the highest pressure and the plate gets a form with a torroidal inflated zone. Under the torroidal inflated zone we model the thick plate in order to have the exact matching form. So when to the system is applied the maximum pressure and the rod is in the minimal volume position, the volume inside the system is null.

e) On and below the plates on their external surface we put some thick plates. So the cyl-piston when the system is in the state of minimal volume has the plane form. In that case too we have losses cause of friction and crashing between plate and thick plate roughly at ½ of the radius. From the group of described solutions the only one that merits to dedicate it a claim is case a. That solution must be said that is a little bit difficult at least for the low technological level of constructions that I want to be dependent on.

In view of the next solution case a) has the special characteristic that when the system is under vacuum and the transmission of forces is done magnetically ( linear generator or linear motor ) it has minimal friction and losses ( given that vacuum is made where the cyl-piston is in order to avoid noise and acoustic losses ). The second group of solutions is based on the idea of pressing on the whole surface hydraulically. So using only one surface we create a closed box containing hydraulic liquid and with that liquid we press the surface on it's whole area.

Alternatively we put both plates in a closed box and we compress hydraulically. To compress the hydraulic liquid we use the usual solution of a hydraulic cylinder and piston.

One could ask: If we use a cylinder and a piston why do we have to use also the cyl-piston ; We do not have to forget that the whole invention is about having big surfaces of contact between compressing or expanding fluid with the "outside world". This is obtained using the big surface of the cyl-piston. But the hydraulic solution has some very interesting aspects that keep it interesting also in case we had a simple alternative solution. One of the problems of using the elasticity of the plates is that the reciprocation is small and so the mechanical construction becomes a little bit complex and big forces are applied to it ( this is valid only for mechanical constructions using shafts - the magnetic transmission doesn't have such problems).

By using hydraulic liquids that have the function of a lever too, we may convert a reciprocation of the plate as small as 1 mm to a reciprocation of a piston in a cylinder by 10cm avoiding so mechanical complications. By using hydraulic liquids also a reciprocation of 0, 1 mm may be used that would be totally impossible to be used mechanically. By using hydraulic liquids we may easily transmit the forces or reciprocation to the cylinders and pistons of a legacy engine and convert such an engine and the associated vehicle ( if any ) to work using compressed air without the need to change the engine and the vehicle. By using the hydraulic liquid we may easily get mechanical energy from a thermo solar system without the use of rods shafts etc.

Generally the hydraulic transmission of energy seems very flexible. The use of hydraulic liquid restores friction into the system but it seems that it is worth the value.

The basic thought regarding the invention is that when we compress or expand fluids in order to make minimal work during the compression or get the maximum work from the expansion we must be able to absorb the heat generated during the compression or furnish the heat in order to keep the fluid at constant temperature during the expansion so both compression and expansion should be isothermal. The heat that is generated or that we must provide is roughly the work that we do during compression or the work that we get during expansion ( supposing that the fluid may be approximated by an "ideal gas". See the section "Energy storage using compressed air and some secrets". In order to be able to absorb or provide the above heat, the quantity and volume of fluid must be small related to the surfaces that exchange such heat.

This isn't accomplished into a normal cylinder ( especially if it is big ) and so in that case the process is more adiabatic then isothermal. So the air must be compressed or expanded between two big surfaces that are very near each to the other ( e.g. at a mean distance of 4mm ). The expression "very near" has to do with the temperatures of the process it's frequency ( cycles per time unit ) and the speed of heat transmission from the surfaces to the fluid.

The surfaces should have in their external surfaces a mechanism in order to transfer the absorbed or provided heat. As has already been said the conversion consist into getting out of the system the rod and the point of force application and to have the object into a box where we have hydraulic liquid. Instead of having two plates we may have only one and so resemble a membrane compressor. The basic idea is that there should be a state of the plate ( membrane ) where the volume of the compressed or expanded fluid is null and another state where that volume is maximum. The volume of the fluid and of the hydraulic "incompressible" liquid have a constant sum because they are inside a fixed volume ( inside a box of constant internal volume ). The difference from a membrane compressor or a pump is that the hydraulic system used to transfer forces is external and independent. The invention has very big surfaces related to the volume ( that means that the ratio between volume and surface is 1 cm or less ) and that the transmission of forces is done by hydraulic liquid ( this isn't true for all membrane compressors ) and that there is a state where the volume of the fluid is null.

In case the invented element is used as a motor I don't know any preexisting example.

The exact description of an implementation of the construction is (figure 1 and 2):

We have a short cylindrical or rectangular box (1 ) or elliptical or of a similar shape with thick walls ( thick with respect to the fact that the internal volume doesn't change when the maximum pressure is applied to the system). Internally to the box, over it's bottom, we put a subtle preferably metallic sheet (4) of the same peripheral shape as the internal bottom of the box. So the metallic sheet covers completely the bottom of the box. The sheet must be so subtle as to be bended by the pressures involved but not so subtle as to break or be deformed permanently. So during the phenomenon the metallic sheet (4) gets bended without going over the elastic limits of the material. This means that during the deformation we do not have losses cause of friction. Instead of the metallic sheet we may use a membrane of high resistance ( e.g. including carbon fibers ) and preferably with good thermal conductivity. Obviously any elastic membrane could be used but the pressures and temperatures involving the phenomena and the need for high thermal conduction aren't sustained well by such material. The metallic sheet ( or membrane ) is clamped at the periphery with the bottom of the box in a completely tight manner ( e.g. by soldering ) or with a metallic anullus.

In the steady state there is null volume between the metallic plate and the bottom.

The base of the box has an input hole (2) from where we may input fluid under pressure

( compressed air, steam etc ) between the base of the box and the metallic sheet (4) that must bend. In the base there is also a hole for exhaust (3). These two holes are provided with valves and may be unified into one valve of input output. Over the metallic sheet (4) there is hydraulic liquid (5) ( if the temperatures are too high the hydraulic liquid may be substituted by other substance - e.g. metal of low melting temperature in liquid state. The box is closed from it's upper part with a cover that has a hole (7) from where a tube comes out (8) that contains hydraulic liquid too. That tube transfers using the pressure of the hydraulic liquid the forces to the outside world (9). When we use the system as a motor we introduce via the input (2) fluid under pressure between the base of the box and the metallic plate ( or membrane ), cause of it's subtlety the plate bends and get's inflated letting fluid to enter between the base and the plate. So the pressure is transmitted from the fluid under pressure to the plate to the hydraulic liquid and the volume of the hydraulic liquid inside the box diminishes cause of the bended plate that takes off available volume. So the hydraulic liquid is obliged to exit from the box via the hole (7) that is on the cover of the box and move into the tube (8) in order to act via pressure to a device (9) that is at the other end of the tube ( we may also abolish the tube and connect directly the device to the hole (7) or incorporate the device in the main box (1 ).

The result has as follows: The fluid under pressure expands in contact with a big surface ( the base of the box and the metallic plate )

By having a great surface of contact with the "outside world", they will be able to receive the necessary heat from it ( getting as a matter of fact that the base has the means in order to transfer the heat - heating circuit , coolers heaters etc ) in order to limit the drop of temperature to an acceptable level in order to avoid a drop in the produced mechanical energy.

The displacement of the metallic plate (4) may be small ( e.g. just 1 mm ) but cause off the great surface of the base of the box there will be a good volume displacement of hydraulic liquid getting out from the tube (8). Depending on the maximum displacement of the plate we can design the internal height of the box to be just a little higher. This must be done in order to minimize the volume of the hydraulic liquid to the minimum in order to avoid dissipation of energy during the minimal compression that is applied to the otherwise "uncompressible liquid".

For the same reason we have to keep low the length and the diameter of the tube (8) ( but keeping hydraulic friction at an acceptable level ).

When the plate is "inflated" it gets a specific form. To keep the volume of the liquid to the minimum we can make the cover of the box to have the same form as the "inflated" plate.

So when the plate is maximally inflated there will be ideally a null volume of hydraulic liquid between the plate and the cover. So the so described "isothermal air expander" works in the subsequent manner:

Using an input valve and the input (2) in the base of the box we release fluid under pressure between the base of the box and the plate. The quantity of fluid that is released is determined from the timing of the valve. The volume of fluid that enters is equal to the volume of fluid that exits so via the position of the piston connected at the end of the tube (8) we know how much volume has been admitted. In case of an electro-valve then there is a control circuit that is controlled by the position of the shaft that is rotated by the piston. This may be implemented by attaching to the shaft a circular surface that has a long circular hole illuminated by leds and detected by a photodiode ( like the mechanism that detects the position in the mechanical mouses for PC ). Instead we may use cams and a camshaft ( like in internal combustion engines ) or a rotary valve of input output. The electro-valve gives us the greatest flexibility. After the admission of pressurized fluid the input valve closes and the fluid starts to expand ( until that time the fluid was transferred at constant pressure from the outside to the inside). The expansion happens without big drop in temperature cause of the great surface of contact with the walls and has as result the expulsion of hydraulic liquid from the box and the creation of pressure and movement at the other side of the tube (8).

At the end of the tube (8) we may connect a hydraulic cylinder ( or an equivalent mechanism ) that may rotate an alternator an electrical generator or a vehicle shaft.

When the fluid is completely expanded and the the plate arrives to it's maximum volume then get's opened the output valve that is connected at hole (3) of the base of the box.

This valve is controlled by the same means as the input valve. The input and output valve may be unified in one rotary valve that get's it's movement from the shaft.

The piston after arriving to it's maximum position starts to go back ( by inertia of the shaft and flywheel, or by a spring or by other suitable means - multiphase motors) so it compresses the hydraulic liquid that presses the plate that expels the expanded fluid that is exhausted via the output hole (3) and the output valve.

When all the expanded fluid ( exhaust ) is expelled the output valve closes while the external piston ( or equivalent mechanism ) has arrived to the bottom dead center.

The input valve gets a control ( electrical, mechanical or positional ) to open again and releases again pressurized fluid between the base of the box and the plate having as result the restarting of the expansion cycle.

Inverting the functionality we may use the invention inside a compressor. Then the piston of the cylinder by going from the bottom dead center to the top dead center creates depression so the input valve ( that in that case is a check valve - going from the outside to the inside ) gets opened by the external pressure and the fluid to be compressed enters the compression chamber ( space between the base and the bended plate ). When the plate is bended completely and the piston has arrived to the top dead center and starts to go back then the input check valve closes automatically.

The fluid gets compressed and generates heat that is absorbed by the great surface of contact of it with the base of the box and the plate. The plate is in contact with the base of the box both at it's periphery and via the hydraulic liquid.

When the fluid reaches the pressure of the deposit that is connected to the output valve ( that is a check valve with direction from the inside to the outside ) then the output check valve opens automatically and the pressurized fluid gets transferred between the compression chamber and the compressed fluid deposit.

When the plate gets plane again and there is no more fluid between the base of the box and the plate then the piston has arrived to it's bottom dead center and starts to return to the top dead center. So the output check valve cause of pressure variation closes and just after that the input check valve opens automatically. So the compression cycle starts again by suction of fluid from the input etc. To increase the effective surface of contact of the plate with the fluid we can cover the internal of the plate ( and of the base of the box ) by material of high porosity and low thermal resistance ( e.g. active carbon with graphite ). It is obvious that such a measure will create a dead space ( non null minimal internal volume ) that diminishes the effectiveness of the system. It is a matter of experimentation ( the easy way ) or of theoretical calculations to find the thickness of that porosity in order to maximize the effectiveness.

Alternative implementations

The system described may be constructed in various ways.

Below I describe the most interesting ones:

A) Construction without box with the use of a gasket.

Instead of the box we may construct the system with a) two equal metallic thick plates of circular or rectangular form b) a subtle flexible metallic sheet or other type of membrane with the same form as the previous plates c) a gasket with the same perimetric form of the above having a thickness of at least the maximum displacement of the flexible plate.

We lay down at first one of the two thick plates ( with two holes), afterwards the subtle flexible metallic plate, afterwards the gasket and afterwards the second thick plate ( with one hole). By sealing the system we have the same result as with the box.

When the system is of rectangular and elongated form then the gasket should have a rounded internal perimeter in order to limit the elastic forces on the flexible plate.

B) Construction with two flexible sheets and gasket.

We use a thick metallic plate with one hole a gasket a flexible plate a second flexible plate a second gasket and a second thick metallic plate with a hole. Between the two flexible plates enters a small tube ( or two ) that serves for the input output. The flexible plates are opportunely plastically deformed to accept that tube/s and sealed by soldering or other method.

The thick metallic covers are semi holed at their periphery ( along the plane of the plates ) in order to allow the entering of such tube without compressing it. Both thick plates have a hole and a tube and both tubes get unified to a bigger one that contains hydraulic liquid and goes to the cylinder or other actuating mechanism.

C) Use of a cyl-piston imerged into hydraulic liquid.

By using a container of fixed internal volume with hydraulic liquid in it and contained in such container two equal plane flexible metallic surfaces one over the other ( with null volume between them ) and peripherally sealed ( e.g. by laser welding ) with one or two holes on the same or different surface for the input and output.

This is the same construction as the application GR 2010100533 but without the point for the application of force instead the surface is immersed into hydraulic liquid inside a container of fixed internal volume. In that case heat is transmitted mainly via the hydraulic liquid and so we must provide for means to heat and cool the hydraulic liquid.

In that case the heat is transferred via the hydraulic liquid and it must be provided a circuit and disposition for heating it. It is possible to have two holes (7) for the transport of hydraulic liquid. In that case inserting a check valve on one of them the liquid will be made to flow unidirectionally in the heat circuit.

D) Multi cyl-piston into hydraulic liquid

We can have a bellows immersed into hydraulic liquid, with an input output as described in figure 6 of GR 2010100533.

E) Construction of radiator type

We take elongated flexible metallic pieces ( e.g. 20cm x 5cm x 1 mm). We organize them in couples and dispose them vertically. We weld the long sides of each couple. On the upper small side we insert one or two small tubes and we deform plastically that part of the sheet in order to accept it. The small tube enters for about 1 cm inside vertically. We dispose e.g. 100 such couples vertically and in parallel between them and at a distance of 3mm between them.

The final system has a dimension of 5cm 20cm and wide (3+1 +1 )mm*100=500mm=50cm We make a rectangular pattern of 50cm ( +2cm ) 5cm ( +1 cm) and of height 2cm.

We put all 100 couples vertically inside the pattern ( 0,3 cm from the bottom ) and we pour liquid metal into the pattern. We insert all 100 small tubes into a bigger one we turn the system and we pour again. The whole system is like a radiator. By putting it into a box of similar internal size, when fluid under pressure is admitted then the flexible surfaces will bend diminishing the volume available to the hydraulic liquid. And so...

F) Construction with cylindrical surfaces

Take two metallic flexible surfaces of e.g. 10m of length and height of 0,5m.

We put both surfaces one on the other. We make a spiral cylindrical roll. The spiral will have a constant inter-distance. With the roll vertical we provide for the entrance of small tubes on the upper part between the two surfaces. The disposition of such tubes may be at regular distances. We weld on the long upper and bottom sides the two surfaces and also on the vertical sides. We check that the system is completely sealed. The whole system is put inside a cylinder of same size where there is inside hydraulic liquid. And so when fluid under pressure is admitted between the two surfaces then the hydraulic liquid is forced to exit the cylindrical container.

Method for the functioning of the system in order to have variable power and regenerative breaking while retaining maximum efficiency

During the expansion of gases in order to generate mechanical energy it is important to maintain the maximum efficiency. So the input valve must admit such a volume of pressurized fluid as to determine the pressure of exhaust gases to be the same as the output circuit pressure ( e.g. this may be the atmospheric pressure for a compressed air motor ).

There are two methods in order to obtain variable power while having the capability of variable power and speed.

A) If the system is connected to a crankshaft, then we construct such crank in order to provide a variable eccentricity ( by using a screw that moves the point of application of such force on the shaft ). The position of the cylinder must be changed too ( this movement may be done hydraulically by variating some dead volume hydraulic liquid inside the cylinder.

While such construction isn't difficult it is a little bit complicated in the coupling of the cylinder position and the crank eccentricity. Besides that I do not feel it could be novel so it isn't claimed.

B) By opting for the fixed crank eccentricity we have that during the rotation the piston displaces a constant volume of hydraulic liquid. Cause of that we must introduce a constant quantity of pressurized fluid ( at a determined pressure ) in order to have at the end of the expansion the required pressure at the output circuit. This obliges us to have a constant developed energy per cycle ( given that the input pressure is constant). If we want to diminish the power we have to diminish the volume of admitted fluid but in such a way at a certain point before to reach the top dead center the pressure will arrive at the level of the output circuit pressure. If the expansion continues the pressure will diminish further and there will be a breaking action. When the piston will reach the top dead center and the output valve opens then we will have the mix of fluids under different pressure with an increase in entropy and subsequent losses. To avoid such problem the output valve must be regulated to open at the moment that the pressure inside the box reaches the pressure of the output circuit. We may also have a different check valve with direction of flow from the output circuit to the expansion chamber. Or the output valve may be a check valve anyway that is controlled also via mechanical or electric commands to be opened when the condition under which the check valve opens isn't satisfied.

By opening at that point during the cycle and increasing the volume of the expansion chamber more fluid will get into the chamber from the output circuit ( e.g. fresh air will enter the chamber from the outside ). This fluid will be expelled from the chamber during the expulsion cycle along with the fluid that got expanded .

Alternatively we may let the piston break from the point of equal pressure until the top dead center and accelerate from the top dead center until the same point and let the output valve open at that point. Any way it seems that in that case we will have some thermodynamic losses so the first solution is better. The above method allows us to have a variable power without sacrificing the efficiency of the motor. A part of the cycle becomes useless ( and generates some frictional mechanical and hydraulic losses ).

With one more modification on the system it is possible to let it produce negative mechanical energy. Suppose we diminish so much admitted fluid quantity to arrive to admit null fluid volume at the start of the cycle. So just from the beginning of the cycle according to what has already been described the output valve is already open and so during the way from the bottom dead center to the upper dead center fluid at low pressure is admitted into the chamber from the output circuit. When we arrive to the maximum volume at the top dead center the output valve is open and the low pressure fluid starts to be transferred from the chamber to the output circuit.

Instead to keep the output valve open until the reaching of the bottom dead center and having so all the low pressure fluid expelled from the chamber to the output circuit we may close that valve at any position between top dead center to bottom dead center. So in such a way at a certain point in the cycle the low pressure fluid starts to be compressed ( and so regenerative breaking is accomplished ). When the pressure of the fluid under compression reaches the pressure of the input circuit we open the input valve and so the compressed fluid inside the chamber is transferred from the chamber to the compressed fluid deposit.

In order to have such a function we may have a second input check valve that has a flow direction from inside the chamber to the input circuit. Or the input valve may be a any way a check valve that is controlled also mechanically or electrically or by other means to open when it is in the condition of counterflow. So if we do not admit at the start of the cycle fluid under pressure and we command the output valve to close before the cycle reaches the bottom dead center then the motor works as a regenerative break. Obviously by changing the position of closure of the output valve we modify the break power.

This means that if the output valve closes exactly at 180 degrees from the cycle start then we have the compression of the maximum quantity of air and so the maximum break power.

If we command the valve to close after the 180 degrees position at 200 degrees of 250 or later then the break power is lower and a lower quantity of fluid is compressed per cycle.

To augment the braking action over the maximum that is obtained when the output valve closes at

180 degrees we can have a variable flow hydraulic valve that limits the flow of oil to the cylinder so we may also have a total block of the motor ( it may be use full to have a kind of ABS in that case in order to avoid such condition in case the motor is mounted on a vehicle).

So the best solution is the subsequent:

We have one input check valve and one output check valve controllable also by mechanical or electric or other means in order to get opened under conditions of counter flow. The input valve is commanded to stay open from the start of the cycle ( starting from the bottom dead center ) for a number of degrees of the total 360 degrees of the cycle.

The degrees that the valve stays open at the start of the cycle determines the mechanical energy that we will have as a result of the expansion. The output valve stays open starting from the mid of the cycle ( 180 degrees ) until some degrees. Afterwards the output valve closes until the end of the cycle ( 360 ). The degrees that the output valve stays closed ( from degrees X>=180 and

X<360 ) determines the energy received during regenerative breaking.

While motor action and breaking could work at the same time it hasn't any sense.

So if we want the motor action then we have that input degrees > 0 while output degrees =0 and if we want regenerative breaking then input degrees=0 and output degrees>0 .

The above method of functioning of a compressed fluid motor is completely generic and independent from it's implementation.

But prior art exists: according to document "acdm 151-200.pdf found in

www.aircaraccess.com/pdf/acdm%20151 -200.pdf on page 156 lines 2,3,4 explains that such a check valve has been set for the variable power regulation of the Mekarski Compressed-Air Tramway Motor.

Besides that bad news for me there are also other bad news:

It is known that regenerative breaking has been employed in tramway According to:

http://www.aqpl43.dsl.pipex.eom/MUSEUM/TRANSPORT/comprair/comprair.htm#so

in the HARDIE COMPRESSED-AIR LOCOMOTIVE.

No details have been found on the actual implementation but given that check valves have been installed different from admission valves it is logical to suppose that such regenerative breaking has been used with two valves and not a unified one.

So my claims will be limited to the unified valve that in it's more versatile form is controlled by a microprocessor and the whole process will be just described by microprocessor software.

The exact method of accomplishing the variable window of opening or closing of the input and output valves isn't of great importance and various solutions may be implemented that are obvious. The solution using a microprocessor is obvious enough that I consider it as disclosed. The opt-electrical solution mentioned earlier may be modified by using a second fixed disk where its aperture is variable by rotation cause of a half circle besides it. So when the light passes from both apertures the command is sent.

Advantages of the expansion element

The need to develop that expansion element was the very low efficiency of existing air motors and compressors. That efficiency has two ways to be measured:

a) Efficiency compared to an adiabatic cycle, b) Efficiency compared to an isothermal cycle. When we expand a fluid we may expand it adiabatically so the temperature of the fluid will decrease during the expansion or we may expand it isothermally providing to the fluid heat at a constant temperature during the expansion ( between these extremes there are the polytropic expansions ). The mechanical energy obtained in each case is completely different. The maximum energy is obtained during isothermal expansion. So in air motors we may measure efficiency in two different ways:

The table of efficiencies of air motors that is found in application GR2010100533 shows that efficiencies related to the isothermal model are very low around 30%. Based on the adiabatic model we have efficiencies that are over 100% cause of the fact that the expansion is never completely adiabatic. All commercial air motors I know of do not take into consideration that important factor that is described into the section "Energy storage via compressed air and some secrets". It may be that in the applications where they are used it's more important their size then their efficiency. We have to say that neither turbines take into consideration that factor because expansion in turbines is essentially adiabatic ( with the exception of heating turbines ).

The invented element is simple and is the basic part of a motor where a fluid is expanded essentially isothermally by receiving heat from the outside using huge surfaces of contact and obtaining high efficiency. The motor is based only on heat to take from the outside and not on heat stored somewhere ( like in Mekarski tramway motors etc ).

The hydraulic system of energy transmission has low frictional losses at low frequencies ( at high frequencies the system has bigger losses ).

Used inside a compressor the element creates a different and more effective compressor because it limits the temperature during compression cause of big surfaces of heat transmission. This means that we can make the ratio between volume and area so big as to limit the losses to a predefined limit. There is obviously a limit over which it is better to accept the losses then to make bigger and bigger the system. It is know that legacy compressors work essentially in an adiabatic manner either turbine compressors or scroll compressors ( at a lesser extent due to the surface of contact ). These compressors try to limit that inefficiency by introducing multiple stages of compression. The maximum isothermal efficiencies found are about 60% to 70% and no technical sheet states that figure probably because it isn't of interest.

Possible uses.

Use in a compressed air motor

With one or more expansion elements and cylinders that are connected to a crankshaft we may have an air motor. If the elements are more than one then they may work in different phases. So the motor will be a multiphase motor. If the cylinders are double acting then they may be half in number than the expansion elements. The expansion elements will function in different phases and counter phases will be connected to the same cylinder on opposite ports.

Use in a compressor

With one or more compression elements equipped with check valves and with hydraulic cylinders connected to a crankshaft we may have a compressor ( as already described ). If the elements are more than one is valid what is valid for the motor.

Use in a Stirling type A engine

The compression expansion element may be used as part of a Stirling engine. In that case are necessary at least 2 elements with two cylinders connected to a crankshaft at a phase difference of 90 degrees ( in the right direction - look at Stirling engines ). The input output holes are unified into one hole and without valves. The two elements have those two holes connected between them with a re-generator in the middle. One element is held at low temperature while the other one at high. By adding 2 more compression expansion elements we may use the second port of the double acting cylinders and make a Stirling Engine of two phases. Such engine should be able to start in any position ( figure to add later ). It is a good choice to select as working fluid one with high coefficient of thermal transmission ( e.g. Helium ).

Use in conditioning cooling systems

A Stirling Engine is a cooling system too if inverted ( another motor moves the shaft ).

Use in an Ericsson type of engine.

The initial idea was to produce an engine that could be used as part of a solar energy conversion installation by use of the temperature differential. The motor (figure 11 ) that I will describe is an Ericsson engine ( second type of cycle - not the Brayton one ).

The motor is the analog of a double turbine ( turbo charger ) where we compress a fluid that get's compressed heated and expanded ( there are some differences regarding the adiabatic of the process). The motor (figure 11 ) is comprised of: A fluid compressor (30), An air motor ( fluid expander ) (31 ), A regenerator ( 36+37). The compressor (30) may be of any type including the type described previously that contains one or more of the described compression-expansion elements and hydraulic cylinders. Such compressor must have a high isothermal efficiency ( around 90% ). The air motor or expander (31 ) may be any such motor including the type described previously ( with one or more compression expansion elements with a hydraulic cylinder connected and attached to a shaft). Such motor should be of high isothermal efficiency ( around 90% ) and should be able to heat the expanded fluid during the expansion using a heat reservoir.

The request for high efficiencies are required in order to be able to work the engine also under low temperature differences. Neither for the compressor neither for the expander I know any such commercially available equipment ( with efficiencies around 90%) ( if not I wouldn't invent I would just implement ). The process is well known and fully disclosed anywhere.

We compress the working fluid ( it may be air, helium, hydrogen, steam or other organic vapors ) and we expel the generated heat to the cold reservoir that we use ( it may be the air, the sea, a lake, the subsoil etc). This happens via passages 32 and 33 and via a liquid of heat transport or via other way of expelling heat. The cycle is almost isothermal ( dictated by the high efficiency requested ). If the working fluid is air then the cycle may be an open cycle so the compression may be completely separated locally and temporarily from the expansion cycle. We may compress air when the external temperature is cold ( at night usually ) or compress air under the sea while the expansion happens at shore.

Obviously the compression and expansion cycles may be connected on the same shaft (38) ( the normal case for a Stirling engine ).

The connection shaft may be mechanical but also electrical ( I mean the connection of the electric motor of the compressor with the generator of the expander ).

The biggest energy result may be obtained when we render the compression and expansion cycles independent each from the other. The pressurized fluid ( usually air ) is stored into deposits of high pressure for later use.

b) We expand the working fluid taking from the high temperature heat resevoir heat at high temperature. This may be obtained with the "contact" of the expanding element with the source of heat ( e.g. by positioning it at the point of concentration of solar radiation and having so the base of the box heated by radiation ) or by heating it with a heating circuit.

In any case the expansion element is heated and so the expanding fluid is expanded isothermally at high temperature. So such fluid enters at high pressure and high temperature ( see why later ) and exits at low pressure and at the same high temperature that it entered ( rougly ).

c) The working fluid exits from the compressor or the compressed air deposit it was stored while the working fluid exits the expander these two flows via a regenarator exchange heat at all temperatures so when the pressurized fluid enters the expander has got the high temperature while when the working fluid at low pressure exits the regenerator and before entering the compressor has the low temperature ( minus some losses due to the regenerator ).

The regenerator may be implemented as two concentric metallic tubes ( the external (36) may also be non metallic for example a glass one or a metallic with internal insulation ). From the internal (37) will flow the high pressure fluid while between them will flow the low pressure fluid. By having a sufficient length the tubes will allow to the hot and cold working fluids to exchange their heat at all temperature values having as a result what has already been described. There will be a thermal loss from the high to the low temperature due to the transmission of heat via the tubes. That transmission may be limited by cutting the internal tube and interposing low thermal conductivity joins ( as glass or ceramic joins ).

What happens exactly: The compressed fluid ( e.g. air ) exits from the high pressure deposit (41 ) at a predefined pressure. It enters into the re-generator (36+37). Into the re-generator it's temperature is increased ( due to the exchange of heat with the fluid that exits the expander ) and cause of the fact that inside that tube there is a uniform pressure the fluid is expanded while pressure is constant.

The expander if the fluid was expanded by the same ratio but at low temperature would provide us with the exact energy necessary to compress the same quantity. But now a bigger volume of fluid at the same pressure enters the expander. So there will be a surplus of energy depending on that initial expansion of volume. The volume is multiplied roughly by the ratio T2/T1 ( high / low ). The result is that if we put on the same shaft (38) the compressor and the expander we will get greater mechanical energy that what we need for the compressor and so we can transfer that surplus from the shaft at point (39) to a point of use (40).

In case we use an open cycle, depending on the needs of energy we may consume less compressed air than that we produce per time unit or the inverse. This may be obtained by changing the ratio of transmission between expander and compressor. Instead of that we may use the technique and method of valve timing to obtain the same result while having a 1 :1 mechanical coupling ratio.

So we have an easy way to store energy or to produce more energy than what could be done normally. The available Stirling engines and generally thermal engines start to work only with high temperature differentials ( ambient temperature 30C to 300C - 500C ). From the above rule exceptions are some "low temperature differential Stirling engines". If we note them we will see that they make use of the basic idea of a big surface of heat transmission with the working fluid. The motor herein described ( the Stirling version ) should start to work with temperature differences as low as 100C ( maybe also lower ). The exact characteristics may vary depending on the kind of cylinders the hydraulic liquid the general frictional losses and the working fluid. Exact measurements will be added when the construction and experimentation is over.

Use for the propulsion of vehicles

The expansion compression element may be used on the roof of vehicles as a system of expansion of compressed air for the propulsion of the vehicle ( or if such a big surface isn't needed we may use the existing radiator or it's space ). It is good if the base and cover of the box have lamels as the car radiators. They could have also provisions for the absorption of solar radiation ( covering with black substances especially devised ).

In case of a new vehicle ( bicycle, motor bike, car , truck ) an hydraulic cylinder connected to a crankshaft that moves the vehicle is sufficient ( such shaft may the wheels shaft).

We may also connect more than one expansion elements. Cause of the fact that hydraulic cylinders of double action are readily available, with one cylinder of double action and two expansion systems we have a double phase motor. The double phase motor may start from any position but not with guaranteed minimal torque (the same is true for two single action cylinders). By using tree single acting cylinders the engine is able to start in any position with guaranteed minimal torque ( three phase motor ).

By using two double acting cylinders and 4 independent expansion elements we have a 4 phase motor. This is the best solution. The 4 phases motor ( like the 3 phases motor ) is able to start from any position with guaranteed minimum torque. The phases are at 90 degrees between them. By using the regenerative breaking and the hydraulic break the system is complete. To distribute the compressed air to the expander elements we may also use a unique rotary valve for the input and output of air.

If the invention is used in a existing vehicle then the existing cylinders are converted to receive the pressure and motion from the expander elements.

Cause of the diversity of motors it isn't possible to explain all cases, so an example will be given and the experienced mechanic should be able to adapt it to the actual case.

By using the example of a 4 cylinder 4 stroke engine the conversion changes it in 2 stroke engine. We lock the valves in their closed position by the cams. We take of the spark and we use the same hole to connect the tube that transfers the hydraulic liquid from the expansion elements. We may choose to use the hole used by a valve in that case we will take off that valve and put the hydraulic power tube.

In such types of engines the pistons move in the same way by couples ( but when working in 4 stroke function they are in opposite strokes ). So we need two different expansion elements at opposite phase ( 180 degrees of difference ). We connect hydraulically the cylinders that move in the same way. So the expansion system pushes two cylinders together. The expansion systems work at opposite phases. If we could change the crankshaft that has two phases with a crankshaft that has 4 phases then it would be the ideal solution. We would have 4 expansion elements and a 4 phase engine ( with guaranteed minimal torque) in any position.

By using hydraulic valves we may use only some cylinders while disabling the others.

Problems of the solution: The solution isn't ideal. It is probable that we will have a limitation on the rotations per minute of the engine due to the hydraulic friction. A newly constructed vehicle is much better ( There are hydraulic cylinders that work at 8000 rpm's).

But in any case the conversion of existing vehicles provides the possibility to move at low speed using compressed air by using the existing fleet. If this is works out to be reliable it is very important in order to change from the economy of fuel to the economy of solar compressed air ( The Ericsson motor described connected to the solar field is a solar compressor ).

Size of the radiator ( oven )

A basic question during the construction of a compressed air car is what would have to be the size of the expansion system of our engine. The thoughts are:

a) We set a minimum percentage of temperature drop in order to have a lower bound to the efficiency of the compressed air motor. We may set e.g. that we want the mean temperature not to drop under 8% of the absolute temperature ( say it is 300K around 27C). This means that we will be able to develop a power that will not drop over the 8% ( without calculating frictional losses) of the value that would be obtained without that temperature drop during the expansion of air. Let's suppose that the temperature of the expansion element is just the external temperature. So the expansion of air generates a temperature differential between the walls to the central plane between the walls. The air near the walls gets the wall temperature while cause of expansion the air is colder at the point that is most distant from both walls. Heat is transferred across the air to such point. So because we set a mean 8% we may suppose that the air will be 16% colder at the central plane. If we work with a maximum displacement of 3mm while the mean air pressure is 100bar ( so the maximum is roughly 200bar ) then the heat transport depends on the conductivity coefficient of air at that temperature and pressure.

Such thermal conductivity for air at the pressure of 100 bar and temperature of 300K is a=0.03144 W / (m*K). By looking at the table bellow that implements the needed calculations we see that we need big surfaces. Also if we cover all the surface of the vehicle with a radiator we will need 5 such radiators. In practice there may be improvements due to the turbulent flow. Such improvements must be measured and quantified.

I have to note that air motors commercially available do not take into consideration such facts. ( Instead old solutions like the Mekarski compressed air locomotive had found ways to resolve such problems). This has as a consequence that their efficiency approximates the adiabatic one and not the isothermal one. These problems would arise especially during winter and in cold places.

Use in a thermosolar system for the production of energy.

The basic use for which has been developed the expanding element is the expansion system of a thermosolar system for the production of energy. In such case it may be used in it's rectangular elongated form ( in the case of linear concentration ) or in it's circular form ( in case of point concentration ). In this case the "box" should have on it's bottom special treatment in order to absorb and do not emit solar energy and heat. Such receptor should be in thermal isolation and in vacuum besides a glass inside another box. Expanding gases ( compressed air or steam ) after being preheated via the regenerator take the necessary heat at high temperature from the solar radiation that heats the bottom of the box and so press on the metallic flexible sheet that transfers the mechanical energy to another cylinder or system for the conversion of hydraulic energy to mechanical.

The air has been compressed via the same mechanism ( or via another one ) at low temperature (it is compressed at the same or different moments)

The difference of work between the compression at low temperature and the work during the expansion at high temperature is the work produced.

We must note here the great difference between the present solution and the one described in application GR2010100533. In the latest solution the system avoids mechanisms ( crankshafts, piston rods etc ) for the reception of forces in a mechanical way with a very great simplification of the whole construction. So we have a simple system of expansion of compressed air ( or steam ) exactly at the point of reception of radiation without thermal losses and the need to transport the heat. Instead of storing the energy in thermal form to use it later, we may store it ( the term store is wrong) in form of compressed air.

It must be noted that in some thermo solar systems the heat transfer liquid enters at a low temperature the circuit and exits at a higher one. In the heat exchanger for steam generation happens the opposite. So the heat is received at various temperatures lowering it's mechanical energy generation potential and augmenting the entropy losses. The same happens in the turbine space.

In our system what oscillates is the hydraulic liquid. The oscillation of the liquid may be converted directly to electrical energy with the use of a linear alternator or generator or with the use of a hydraulic cylinder connected to a rotary alternator or generator.

Another way to work the system is to transform the alternating current of liquid into direct current of liquid with the use of a check valve and two tubes with hydraulic liquid exiting from the box. So the flow will be unidirectional. We may insert in such circuit a "hydraulic generator" that is commercially available. It may be necessary to make such flow more steady with the use of some hydraulic capacitors. To understand exactly let's look at a electronic circuit of conversion of alternating current to direct stabilized. The rectification of the liquid flaw may also be used to impose to the liquid to flow inside the the solar collector. We may also use not absolute check valves but check valves that impose a non uniform flow during oscillation but that leave the liquid go back and forth but more forth then back.

By looking at the previous calculations we have arrived to the result that the system may exchange 1257,6 W/m^A2 . If the calculations are correct then with a simple surface we may transform only simple and not concentrated radiation ( except if the covering of the surface with active carbon etc changes the situation). So in the design of a concentrated solar system it is better to use working fluids with a bigger factor a ( see the previous table ) ( e.g. Helium that has 5 times such a ) and using inside the collector more then a surface ( more vertical surfaces - radiator type ). Compressed air energy storage and some "secrets"

City-wide compressed air energy systems have been built since 1870. Many tools work by using compressed air and the field is fully developed.

Some times a deposit of compressed air is called "compressed air battery". The title of the article speaks about storage of energy using compressed air. The term CAES has been coined to mean Compressed air energy storage.

Some people believe being mis-leaded from the above terms that compressing air ( and giving mechanical energy to such air in order to compress it ) we are able to store that energy into the compressed air. For that reason such a deposit may be called a "compressed air battery".

I have to note that such believing are completely wrong.

We may approximate the behavior of air and compressed air with an ideal gas. Then the energy that is stored into air in form of internal energy depends only on the degrees of freedom of the molecules on their number and on the temperature.

Such equation may be written as E=(f/2)*N*k*T where f are the degrees of freedom ( 3 for a mono-atomic gas, 5 for a diatomic etc ). N are the number of units ( atoms or molecules ), k is the Boltzmann constant, T is the absolute temperature ( expressed usually in degrees Kelvin ).

So one billion of molecules of air at the same temperature have the same internal energy independent from their volume and pressure. What is different is the entropy of the system.

A system where molecules are limited to a narrower space ( and so a greater pressure is developed ) has lower entropy while a system where molecules are limited in a bigger volume ( at lower pressure ) have bigger entropy.

This means that when we compress air ( isothermally ) we just give our precious mechanical energy and we waste it into heat developed during the compression. That heat is expelled into the ambient. But cause of the fact the process is roughly reversible we do not increase the entropy of the world. We convert our precious mechanical energy into heat ( having so an increase in entropy ) but we have been able at the same time to diminish the space where such air was stored so the entropy of that air has dropped. The total entropy variation ( in the ideal case ) is null. This means that by compressing air we extract entropy from it. We don't store any energy nowhere. Or better said: While compressing air we store the work given into heat stored in the ambient. This is one side of the process. The other side is that by using such low entropy compressed air we may use it as a "catalyst" ( just to use a chemical term ) to convert later thermal energy to mechanical one. So the compressed air is only the "catalyst" that has a predetermined "catalytic capability - the entropy" but we have to find the source for the heat to absorb and find the receptor of the produced mechanical energy. If we do not find a source of heat, we may anyway get that heat from the air itself and diminish it's temperature generating so mechanical work. But such process will leave us with very cold air that should be released into the ambient having so a non reversible entropy wasting process. In order to get the maximum mechanical energy ( in case we do not have a heat source different from the ambient ) we have to construct a motor that is designed in order to being able to absorb such heat. Such design has to do with the thermal conductivity of air and the surfaces involved into transferring the heat to such air. If the motor isn't designed in order to be able to absorb such heat and being able to transfer it to the expanding air then that motor will be unable to provide isothermal like efficiencies and will behave as an adiabatic expander. This will be much more visible when the motor works at maximum power and needs to absorb a heat equal to the power that it develops. In the ideal case the exhaust air is at ambient temperature and all power generated is absorbed as heat by the motor. I do not know any motor that is designed with such concepts in mind. So it is natural that the isothermal efficiencies of air motors are around 30%.

This subtle but simple particular drives us to loose great quantities of energy in the compressed air systems generating economical losses. So I will state that an air motor is as good as the system of heat absorption and transmission it has.

Inversely a good air compressor is as good as the heat expulsion systems it has.

So concluding I must say that the systems for the storage of energy using compressed air, do not store any energy. Do not have nothing to do with chemical batteries ( where there is stored energy in chemical form ).

The above reality has created an impression that compressed air isn't an efficient way of storing energy and that the "energy density" of compressed air related to it's weight is low, so a compressed air car has a low autonomy ( related to a predetermined deposit size ).

Such opinions are the result of a flawed design of air motors. By using a correct design we may obtain efficiencies of 80% or 90% ( related to a isothermal model). This increases the autonomy of a vehicle. We have to note that old tram air motors where designed in the correct manner by taking into consideration the heat factor. Newer designs probably have loosen the experience of the past.

Claims

Claims

1 ) An equivalent of a cylinder with piston used for the compression and expansion of fluids consisting of two thin flat surfaces of equal shape (preferably circular or rectangular) made preferably of metallic material of high elasticity, each on the other and hermetically sealed at the periphery ideally having null dead volume. The assembly has hole/s for input-output valves. The surfaces while being flat on the contact part may have on the other part structural nerves heat absorption or dissipation exchangers. There are attachments for rods and one or two may be added.

2) An object of claim 1 with the modification that one of the two surfaces is thick and/or not elastic and doesn't take part into the process of volume variation.

3) An assembly where many objects of claim 1 or 2 are pilled and sealed opportunely to create a multiple assembly with common input/output/input-output. Each pilled object communicates with the adjacent through two small holes of fluid inter exchange hermetically sealed. Such stack has bigger elongation during expansion while having the same acting force and being controlled by only one input output or input-output. Accordingly there are only two points for the application of forces.

4) Object of claim 1 to 3 with the modification that internal surfaces aren't flat but have some other shape in order to increase the surface of heat exchange. The internal shape of one surface is specular to the other. Ideally the dead volume should be null.

5) Object of claim 1 to 4 with the modification where the flexible surface/s are constructed in order to have an asymmetrical coefficient of bending having the easiest bending towards the outside direction ( when inflated ). Ideally this should impede completely to bend in the reverse manner. So during compression the minimal volume should be null.

6) Any object of claims 1 to 5 with the modification where the internal surface of the plates is treated by the addition of high thermal conductivity porous material (e.g. active carbon with graphite) in order to increase the effective surface of heat exchange.

7) Any construction having input/s output/s or (inputVoutput)s and one or more pairs of surfaces of any kind including those described in claims 1 to 6 sealed between them and assembled as a whole where each pair of surfaces at rest contains ideally null apparent volume ( "apparent" makes provision for the case of porous material) while using the input and output is possible to admit or suck compressed fluid between each pair. The pair assembly unifies all these pairs offering a sealed system with one or more input/output/input-output. The pair assembly is contained inside a fixed internal volume container along with hydraulic liquid. Part of the container may share some common part with some of the pair assembly surface/s. The container is equipped with at least a tube exiting from it and being in hydraulic continuity with the inside of the container. Such tube meant to act on a transducer converting hydraulic energy to mechanical or other ( e.g. Cylinder with piston - the transducer could be incorporated in the container eliminating the tube). Increasing the volume between the surfaces, the volume of hydraulic liquid inside the box diminishes equally, hydraulic liquid exits the container acting on the transducer.

8) Any of the objects of claims 1 to 6 equipped with points for the application of forces and with at least a connecting rod and so being an equivalent of a cylinder with piston.

9) An object of claim 7 equipped with a hydraulic cylinder (or equivalent transducer) being used so as an equivalent of a cylinder with piston.

10) An object of claim 8 or 9 where the object is used being "inflated" by internal or external pressurized or burning gases having the the elastic surface/s bended in the outside direction and being used for the production of mechanical work.

11 ) The object of claim 8 or 9 where the flexible surfaces in that assembly are being deformed by external mechanical force that has as effect the bending of surfaces sucking or admitting fluid and successively compressing and pumping it.

12) Any uni phase of multi phase engine using objects of claim 8 to 9.

(e.g. Stirling type A engine using at least 2 cylinders with piston or equivalent where at least one of them is an object of claim 8 or 9. The two cylinders are in phase difference preferably of 90 degrees and between the input-output of one cylinder and input-output of the other there is preferably a re-generator. The rods are connected to a crankshaft. If the cylinders are more then a pair then each pair may be in a different phase the delay between hot and cold cylinder must be in the same direction then the first pair. If the cylinders are double acting then the same cylinder may be used by objects of claim 8 or 9 when that objects are in opposite phase) The engine may be without crankshaft, instead a linear motor or alternator along with an object of claim 8 or 9 may constitute an electrical compressor or compressed air electricity generator.

13) Method for the efficient functioning of a motor, a compressor, or a motor-compressor, for the efficient variable power functioning of the engine, and the efficient regenerative breaking of it, where at least two check valves controllable to get opened in counter pressure too are connected (in counter flow direction) between high pressure container to the chamber and from the chamber to exhaust circuit. In order to function efficiently the quantity of admitted compressed fluid shouldn't be more than what is needed in order to have at the end of the expansion a predefined exhaust pressure ( usually the atmospheric one). So the input valve is commanded in counter pressure from the start of the cycle to the end of the admission part. The output valve works in counter pressure from the end of the expulsion cycle ( start of the compression part ) to the end of the cycle. Valve timing may be mechanical, electrical, hydraulical, cam guided, microprocessor controlled etc.

14) Method for the conversion of a legacy ( diesel or gasoline ) engine or compressor to work by compressed fluid ( usually compressed air ) where at least an object of claim 7 is used that transmits the developed forces to the existing cylinders of the engine via hydraulic liquid ( using an existing or new hole into the cylinder ). For each cylinder phase there must be a differently timed object of claim 7. The method of claim 13 may also be used on the objects of claim 7 having as result the variable power and regenerative breaking of the existing engine. Where the engine while having more than 2 cylinders has only two phases on the crankshaft then that may be replaced with one with as many phases as cylinders ( at least 3).

15) An assembly of expander (motor) and coupled compressor (they may be equal) where at least one object of the previous claims is used in at least one of them. The expander and compressor are mechanically electrically hydraulically coupled collocated or dislocated. They form an Ericsson engine compressing cold fluid expelling the heat to a cold heat reservoir and accumulating it into a deposit. The cold compressed fluid is heat regenerated with expanded hot fluid coming from the hot part of the engine. So at the expander arrives hot compressed fluid while at the compressor arrives cold expanded fluid. So the expanding inside the expander generates mechanical energy. That drives the coupled compressor to compress the fluid.

By assuming a mechanical coupling of compressor and expander, the ratio of coupling may be altered by the method of claim 13 leading to two possible cases: a) the compressor compresses more fluid than the expander expands. In that case the fluid needed is got from the ambient ( case where the fluid is air ). The cold compressed air reservoir fills up. b) the expander expands more compressed air than the compressor compresses. In that case the deposit empties.

16) Solar system for the production of electric energy using as system for the reception reflection and concentration of solar energy one of the solutions of claims 18 to 28 and a photovoltaic collector.

17) Solar system for the production of energy using a system for the reception reflection and concentration of solar energy of claims 18 to 28 and having directly on the reception part the hot part of one of the engines of claim 12 or 15 or any other such engine. Alternatively heat may be collected and stored using it at a later or same time to feed the engine with a hot heat flow.

18) System formed by a reflector and a receiver. The reflector is formed by a flexible (or formed from inflexible pieces but flexibly connected between them "flexible by strips") reflective surface having preferably rectangular form (any form may work) anchored from two sides with linear horizontal supports (preferably parallel) ( the supports may not be horizontal instead they may decline from north to south if the morphology supports it ) at the same or different height and free from the other two sides having thus it's form modeled by the gravitational force and becoming a linear 3D catenary similar to a linear parabola concentrating the solar radiation on the second part of the system that is a mobile receiver moving circularly (on the 2D section) with center the bottom of the parabola and tracking the linear focus of the reflected radiation) (figure 47002).

19) Apparatus according to claim 18 where the form of the surface is modeled not only by the gravitational force but also by other forces (applied with wires - cables or by other means) that have as effect to change the direction and intensity of the total force exerted to each ideal piece of the surface in a uniform manner in such a way that the flexible surface reacts as being in a uniform gravitational field with different direction and intensity thus getting the form of a catenary or parabola with a different axis (inclined with respect to the perpendicular). In this way the solar position may be tracked in one direction. If tracking is effected in real time modality then the receiver may also be kept fixed ( or almost fixed ) (figure 47010 ).

20) The system in claim 18 or 19 where the mobile receiver is split into two parts moving in different manner and subject to the conditions of receiving all the reflected radiation while minimizing the total receiving surface. The movement of the receivers is roughly described as done by two arms with one edge fixed at the focus of the parabola while to track the diverging angle the arms grow equally in size and diverge in angle between them (figures

47007,47008,47009). The exact angle aperture and arm grow is pre-calculated via simulation and applied by the use of programmable microprocessor or similar.

21 ) A system composed from a fixed array of linear catenary reflectors prearranged in such a way as to have the sun rays pass trough a linear focus (or a limited flat area in the case of flat rectangular areas) given a specific incident angle and a tracking system as described in the previous cases ( single receiver or splitted one) (figure 47011 47030). In the case of catenary through surfaces these may have that form or they may get that form from the gravity force of by forces as in claim 19.

22) A system as in claim 21 where instead of linear catenary there are flat reflectors.

23) Multiple systems of claims 18 to 22 where each linear reflector is situated adjacent to the previous one while over each one there is a receiver. In that case the receivers move all together or the receivers may be kept fixed and the surfaces move under them in the inverse manner - in order to generate the same relative motion.

24) System of claim 18 where the receiver is fixed with respect to the two horizontal supports and on the focus line of the linear catenary while it may move along that line for a defined interval. The whole system may rotate along a vertical axis tracking the sun and keeping concentrated the solar reflection along the linear focus of the catenary surface.

25) System of claim 18 where the catenary is flattened down being formed by pieces of confocusing catenaries. The system may rotate along a vertical axis (figure 47030)

26) Systems of claims 18 to 25 having the reflective surfaces in strips interleaved by space in order to let the wind pass through. The reflective surfaces may be tensioned in the longitudinal direction by connecting them with some material ( between the strip of space ) in order to tension the whole line starting from the beginning to the end of the catenary (many such tensioning lines may exist ).

27) The system of claims 18 to 26 where the supports for holding the reflective surfaces and the collector are wires, kept at fixed distance at the start, end, and in the middle (if necessary) by rods, the whole system if necessary is rotated along a vertical axis by means of wires sliding on two preferably parallel horizontal supports that have preferably an east west direction while the holding wires are elongated accordingly preferably by a mechanism of automatic tensioning

( e.g. a connected weight ).

28) Any of systems in claims 23 to 27 where the end of the catenary through is equipped with a vertical mirror thats sends back to the collector the radiation that would escape otherwise.