CA2262980A1 - Internal combustion engine with extended working cycle - Google Patents
Internal combustion engine with extended working cycle Download PDFInfo
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- CA2262980A1 CA2262980A1 CA002262980A CA2262980A CA2262980A1 CA 2262980 A1 CA2262980 A1 CA 2262980A1 CA 002262980 A CA002262980 A CA 002262980A CA 2262980 A CA2262980 A CA 2262980A CA 2262980 A1 CA2262980 A1 CA 2262980A1
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B75/00—Other engines
- F02B75/02—Engines characterised by their cycles, e.g. six-stroke
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B47/00—Methods of operating engines involving adding non-fuel substances or anti-knock agents to combustion air, fuel, or fuel-air mixtures of engines
- F02B47/02—Methods of operating engines involving adding non-fuel substances or anti-knock agents to combustion air, fuel, or fuel-air mixtures of engines the substances being water or steam
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M25/00—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture
- F02M25/022—Adding fuel and water emulsion, water or steam
- F02M25/0227—Control aspects; Arrangement of sensors; Diagnostics; Actuators
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M25/00—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture
- F02M25/022—Adding fuel and water emulsion, water or steam
- F02M25/025—Adding water
- F02M25/03—Adding water into the cylinder or the pre-combustion chamber
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M25/00—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture
- F02M25/022—Adding fuel and water emulsion, water or steam
- F02M25/032—Producing and adding steam
- F02M25/038—Producing and adding steam into the cylinder or the pre-combustion chamber
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B75/00—Other engines
- F02B75/02—Engines characterised by their cycles, e.g. six-stroke
- F02B2075/022—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle
- F02B2075/025—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle two
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B3/00—Engines characterised by air compression and subsequent fuel addition
- F02B3/06—Engines characterised by air compression and subsequent fuel addition with compression ignition
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/12—Improving ICE efficiencies
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Output Control And Ontrol Of Special Type Engine (AREA)
- Combustion Methods Of Internal-Combustion Engines (AREA)
- Characterised By The Charging Evacuation (AREA)
Abstract
An internal combustion engine with reciprocating or rotary pistons and cylinders includes a working or combustion chamber (1) with cylinders (2) and one or more pistons located therein, an inlet pipe for gas feeding (4) with intake valves (5) to the combustion chamber, an exhaust pipe (7) with discharge valves (6) from the combustion chamber, a first fuel feeding unit for supplying primary conventional fuel through a carburettor (8) or an injector (20) and secondary fuel through injectors, a second feeding unit (10) for supplying through an injector a fluid designed to extend the engine working cycle, and at least one ignition device (9) for igniting the fuel supplied to said combustion chamber (1).
Description
W098/06935 PCT~P97/04343 Internal combuQtion engine having an extended operating cycle The invention relates to internal combustion engines according to the precharacterizing clause of Claim 1.
Such internal combustion engines play a major role in modern industry. While internal combustion engines, for example steam turbines and nuclear reactors combined with turbines, make up a considerable proportion of electrical power generation, they are limited to large installations and represent only a small portion of the installed power capacity.
Environmental activists are very strongly in favour of the Stirling engine, but, although this is regarded as favourable from the thermodynamic stand point, at the moment it cannot compete with the engines mentioned above in terms of mechanical efficiency or power density.
Present-day internal combustion engines can be operated only within a very narrow range of power density, efficiency and engine life. They are heavily dependent on engine size (power, cylinder volume), engine speed, fuel type and the materials used. Piston engines with self-ignition (diesel) or external ignition by means of spark plugs (Otto-cycle engines) or turbine engines (Rankine, Brayton or mixed cycle) or a combination of these are preferably used depending on the application, for example motor vehicle propulsion, boat propulsion, aircraft propulsion, drives for electrical power generation, pump drives or the like.
Each type of machine has its own, narrow operating envelopes and its preferred operational envelopes.
Extension of these operating conditions or of the operational envelope has been the subject of extensive investigations and developments since the invention of ~ W098/06935 PCT~P97/04343 internal combustion engines. In this case, progress has been achieved on the basis of further developments in the materials used, improved combustion control, more effective fuels, weight reductions, better engine cooling, streamlined flow paths, improved valve control and, recently, computer-aided engine control. Seen overall, however, development progress with regard to increased power density, efficiency and engine life has remained relatively modest. The maximum efficiency of commercial engines, at the moment, is about 44% at
Such internal combustion engines play a major role in modern industry. While internal combustion engines, for example steam turbines and nuclear reactors combined with turbines, make up a considerable proportion of electrical power generation, they are limited to large installations and represent only a small portion of the installed power capacity.
Environmental activists are very strongly in favour of the Stirling engine, but, although this is regarded as favourable from the thermodynamic stand point, at the moment it cannot compete with the engines mentioned above in terms of mechanical efficiency or power density.
Present-day internal combustion engines can be operated only within a very narrow range of power density, efficiency and engine life. They are heavily dependent on engine size (power, cylinder volume), engine speed, fuel type and the materials used. Piston engines with self-ignition (diesel) or external ignition by means of spark plugs (Otto-cycle engines) or turbine engines (Rankine, Brayton or mixed cycle) or a combination of these are preferably used depending on the application, for example motor vehicle propulsion, boat propulsion, aircraft propulsion, drives for electrical power generation, pump drives or the like.
Each type of machine has its own, narrow operating envelopes and its preferred operational envelopes.
Extension of these operating conditions or of the operational envelope has been the subject of extensive investigations and developments since the invention of ~ W098/06935 PCT~P97/04343 internal combustion engines. In this case, progress has been achieved on the basis of further developments in the materials used, improved combustion control, more effective fuels, weight reductions, better engine cooling, streamlined flow paths, improved valve control and, recently, computer-aided engine control. Seen overall, however, development progress with regard to increased power density, efficiency and engine life has remained relatively modest. The maximum efficiency of commercial engines, at the moment, is about 44% at
2 300 rpm or 8.2 MJ/kWh or 144 g Gasoil/Hph or 192 g Gasoil/kWh (10200 cal/g - 42.707 J/g). Maximum efficiencies which can be achieved at the moment with slow-running engines (for example Sulzer two-stroke diesel at 76 rpm) are in the order of magnitude of 50%.
The use of water in conjunction with ethanol was investigated, with limited success, by Gunnermann (WO
91/07579). Gunnermann used aqueous alcohols with 40 and 60% water dilution. He found that an expensive and complex platinum catalytic converter was required inside the combustion chamber in order to assist the initiation of combustion, in that the hydrogen bonds in the fuel mixture were activated. Gunnermann incorrectly interpreted the high fuel efficiency as additional release of heat, which was caused by dissociated water. A simple heat balance shows that this does not occur since the heat released from the combination of hydrogen and oxygen is equal to the heat which is absorbed in the dissociation. Only the Pt value allows ignition in mixtures which would otherwise be too damp for ignition. However, Gunnermann's engine had problems with regard to its stability, reliability and costs, and was limited to a water:fuel ratio of 1.5:1.
The use of a cycle extension fluid has been practised to a limited extent in gas turbines. The W098/06935 PCT~P97/04343 injection of steam into the combustion chamber, which was originally intended in order to reduce soot formation and to promote the combustion process, resulted in increased power emission from the turbine, and an improvement in efficiency. Further investigations by a large number of inventors lead to the so-called SAGT or Steam Augmented Gas Turbine. The SAGT operates with steam injection downstream of the combustion chamber. In this way, the temperature after combustion can be raised to a considerably higher level than the expansion turbine can withstand, and steam injection reduces the temperature back to a level which is acceptable for the expansion turbine, and converts the heat into a large volume. The SAGT has been improved further and a "CHENG point" has been defined at which the efficiency of the SAGT reaches a maximum by injecting exactly the amount of saturated steam which can be produced by heat recovery from the exhaust gases. However, the CHENG point does not correspond to stoichiometric combustion, since excess oxygen is present.
A further step was taken by Urbach & Knauss, who brought the SAGT to stoichiometric combustion conditions, and accepted a higher power density at the expense of slightly reduced efficiency. Urbach &
Knauss achieved this by operating a first combustion chamber at high pressure, followed by steam injection with subsequent expansion to an intermediate pressure.
In this way, the combustion gases were cooled both by steam injection and by partial expansion. A second combustion chamber consumed the remaining oxygen, and this was followed by steam injection and final expansion. However, Urbach & Knauss did not go beyond this development stage.
The cycle extension fluid can advantageously be used as a carrier for chemicals which promote - W098/06935 PCT~P97/04343 combustion. Additives of peroxides to the fuel were already known from Lindstrom (WO 88/03550) in order to reduce the content of CO and HC residues in the exhaust gases. The addition of peroxides to the cycle extension fluid eliminates mixing, storage and shelf-life problems with fuels which are otherwise doped with peroxide.
DE 21 27 957 B2 discloses a system for the injection of an anti-knock fluid, which may be water, in order to reduce the combustion temperature. The fluid is injected before the compression stage, so that compression energy can be saved and the risk of premature ignition (knocking) is reduced by decreasing the temperatures after compression (that is say before ignition). This contains no reference to the possible introduction of more fuel into the same cycle or to isochoric combustion. Such an engine is a conventional internal combustion engine, irrespective of stratified charging, turbo charging, an Otto-cycle, diesel cycle or comparable cycle, or whether secondary or multiple fuel injectors are present.
DE 43 01 887 A1 states, in particular, that the addition of water or some other secondary fluid is based on the use of waste heat from the traditional method for vaporization, leading to a general reduction in temperatures and thus to a reduction in the contamination with, for example, NOx. In this case, the water must either be preheated or converted into steam by reusing waste heat from the exhaust gases (which is possible within very narrow limits with gas turbines, but is in practice impossible with piston engines owing to the very high pressures and the time available for injection), or the water has to be applied in liquid form to hot surfaces within the cylinder, but without taking any heat from the burnt fuel/air mixture (also, only a very small amount).
.
- W098/06935 PCT~P97/04343 This shows that no consideration was given to the possibility of injecting more fuel per cycle.
The use of more than one fuel injector in a combustion chamber is known in the prior art, but always for purposes other than that in the present invention. Multiple injectors are typically used for pistons with very large bores, in which the aim is to reduce the size of the mixing region. According to the present invention, the reason for optionally using multiple fuel injectors is that a step-by-step combustion sequence may be desirable, which is difficult or impossible to achieve and/or to control if a single injector is used. According to the invention, different fuels may be used in different injectors so that, for example, combustion is initiated by using a high-quality fuel in the first injector, with this being followed by combustion of lower-quality fuels, or fuels mixed with water or with other chemicals, in the other injectors. The invention relates to the use of the injectors.
US 54 00 746 A discloses the use of hydrogen peroxide as an additive to conventional fuel in order to reduce the peak combustion temperature. This is necessary here since it has not been recognized that it is possible to improve the efficiency of combustion by the injection of sufficient fuel and by the timing of injection of water. This known method leads to the flame being extinguished when water is injected. The only option is oxygen enrichment or oxygen addition by the use of hydrogen peroxide. This does not cover the teaching of using additional oxygen, which is available in order to inject more fuel and to obtain more power from each cycle.
In contrast, the object of the invention is to expand the range of power density, efficiency and - 5a -DE 29 25 091 A1 discloses an open-circuit internal combustion engine, in which the combustion air is isothermically compressed within a compressor, is burnt with injected fuel, and the combustion gases are isothermically expanded before they are released isothermically. Water is injected in such a manner and in such quantities that it is evaporated during the compression of the combustion air. Injected water is not used for decreasing the combustion temperature and for increasing the amount of fuel, which is transformed by air unit; rather, water is injected concerning the amount and the manner as part of the compression cycle so that partial isothermic compression will be obtained. This is followed by an adiabatic isotropic compression up to extremely high pressure values so that the heat generated by compression will reach temperatures of more than 800~ C. Then, combustion will be carried through continuously during the expansion phase so that an approximate isothermic expansion will be obtained, whereby this part of compression corresponds to the Carnot portion of the cycle.
BE17834.DOC
1.2.991:01PM
W098/06935 PCT~P97/04343 engine life beyond the levels of conventional motors and engines.
This is achieved according to the invention, in the case of an internal combustion engine of this generic type, by the features in the characterizing part of Claim 1, and by a method having the features in the characterizing part of Claim 9. Further refinements of the invention are the subject matter of the dependent claims.
In principle, the proposal in the present invention is to use water or some other fluid which is chemically inert or can be decomposed endothermically, and to pass said fluid into the combustion chamber or chambers in order to make a greater amount of fuel available per cycle and thus to improve the operating power of internal combustion engines. The fluid used for this purpose is a secondary fluid, which is called a cycle extension fluid (CEF). This fluid makes it possible to use a similar or higher fuel/air ratio without any disadvantageous effects on the temperature/pressure graph for the engine, which is the critical factor for long engine life. In this case, high temperature is exchanged for increased pressure and/or increased volume, in that an additional substance is vaporized and/or endothermically decomposed. This substance is preferably water, since any required amounts of water are available, it is easy to handle, and presents no environmental problems whatsoever. However, other fluid additives may also be used for specific applications.
While the use of combustion air enriched with oxygen, or even of pure oxygen, or the use of secondary, oxidizing substances, such as nitro or peroxy components gives only limited advantages since, owing to the temperature limits, only a small portion W098/06935 PCT~P97/04343 of the oxidizing substance can be utilized and stoichiometric operation is precluded, the use of a CEF
achieves a major improvement since, in comparison with conventional applications, up to five times the amount of energy can be converted per cycle. An engine operating with pure oxygen can be operated without any NOX emission and with easily controllable CO2 output, which can be cleaned in a simple manner for subsequent industrial use.
According to the invention, water is injected in liquid or gaseous form into the combustion chamber in order to increase the pressure and/or the volume while the rise in the temperature of the operating fluid is slowed down, or the temperature is stabilized or reduced. This allows higher fuel/air ratios, which would otherwise lead to excessively high temperatures in the operating fluid, to the detriment of long machine life. In this case, gas, solid material or a liquid other than water may also be injected into the combustion chamber, in order to achieve the same effect as water. Such a medium should either vaporize and convert heat into a large volume or high pressure, or should result in endothermic dissociation in order to achieve a large volume or partial pressure of decomposition products. In the case of a gas turbine, the combustion takes place isobarically, and the fluid produces a large volume. In the case of a piston engine, combustion takes place partially isochorically, and the fluid produces a high pressure.
The amounts of water injected may be up to twenty times the amount of fuel used. This means that a large water reservoir or a system for recovering water from the exhaust gases is used. Since the exhaust gases are considerably cooler than was previously the case, this can be achieved using very simple means, preferably by cooling close to the dew point using dried exhaust ~ W098/06935 PCT~P97/04343 gases in a heat exchanger, followed by wet washing with further cooling in the washing water cycle. Recovered water holds a large amount of residual impurities, which can be introduced into the cycle once again, and can be burnt.
This technique allows very high power densities to be achieved since more energy can be introduced into an operating cycle for an equivalent or lower theoretical cycle efficiency, to be precise with a comparatively equivalent or better overall efficiency for conversion into mechanical energy. In the case of an engine with spark-plug ignition, a small range of materials may be used in order to achieve power densities which at the moment can be achieved, for example, only in expensive racing-car engines, with engine lives which far exceed those of conventional designs. This technique also makes it possible for engines with self-ignition to achieve equivalent or higher power densities than engines with external ignition, since the upper temperature limit is raised. In the case of gas turbines, this technique makes it possible to increase the power densities by a factor of 5 or more, since the upper temperature limit is raised (WO 94/28285). In the case of steam-augmented gas turbines, SAGT, improved efficiency can be achieved and, with engines according to Urbach & Knauss, increased power density can be achieved. The latter engines have brought the conditions for SAGT turbines up to stoichiometric combustion, but options for operating at reduced temperatures (in order to achieve the advantage of lengthened engine life) are not recognized, nor is the potential for operation with oxygen augmentation or pure oxygen exploited. Limiting the peak temperature when using fluids is important from the environmental aspect, in terms of reducing NOX emissions.
W098/06935 PCT~P97/04343 g Minor added amounts of water with, for example, 0.01~ H2~2~ O3, organic peroxides or other oxidizing substances are sufficient to clean residual CO and residual HC from the exhaust gases. The addition of peroxides to the water base overcomes storage and shelf-life problems of fuels doped with peroxide in some other way. Minor additions of H2O2 or O3 can be achieved simply by on-line electrolysis of water.
Stronger concentrations of peroxide can be used in order further to increase the power density, in that a portion of the oxidizing substance is supplied.
Engines can be operated with air enriched with oxygen or even with pure oxygen. The latter would result in no NOX whatsoever being formed, and in the exhaust gases being composed exclusively of CO2 and water. Water can be condensed and recycled, and CO2 can be used for industrial processes or for addition to the air in greenhouses or the like.
Water can also be mixed with water-soluble fuels or fuels which can be dispersed in water. The ignition process is achieved by a concentrated fuel charge, and the fuel diluted with water can then be burnt in an aqueous environment. This application is limited by the situation in which all the fuel is supplied in an aqueous base, this being equivalent to Gunnermann's proposal, which proposed aqueous alcohols in 40 and 60~
aqueous solution and required an expensive platinum catalytic converter in the combustion chamber in order to assist the initiation of combustion, in that the hydrogen bonds in the fuel mixture were activated. The high fuel efficiency for additional release of heat, which was caused by dissociated water, was not identified by Gunnermann. A simple heat balance shows that this is not true, since the heat released from the hydrogen/oxygen combination is equal to the heat absorbed in the dissociation. The Pt allows only one - W098/06935 PCT~P97/04343 ignition in mixtures which would otherwise be too wet for ignition. In this case, Gunnermann's engine ran into stability, reliability and cost problems, and was limited to a water:fuel ratio of 3:2, while considerably higher levels could be achieved with the present invention.
The invention results in the capability to operate an internal combustion engine of this generic type in a region of power density, efficiency and machine life which until now has not been feasible. This is achieved in that a fluid which extends the cycle is added, and either the amount of fuel added per cycle is increased or the cycle is modified towards higher pressures.
The invention is explained in the following text with reference to exemplary embodiments in conjunction with the drawing, in which:
Figures lA - lC show schematic illustrations of basic design embodiments of an internal combustion engine according to the invention, Figures 2 - 7 show various applications of P/V graphs (A) and T/V graphs (B) for machines according to Figures lA - lC, and 30 Figure 8 shows a specific embodiment of the invention, relating to the provision of the cycle extension fluid.
In the embodiment according to Figure lA, one or more combustion chambers 1 having cylinders 2 and a corresponding number of pistons 3 are fed with supply gas by a line 4 via inlet valves 5. The exhaust gases produced from the combustion are dissipated via outlet W098/06935 PCT~P97/04343 valves 6, through an exhaust gas line 7. Fuel is introduced to the combustion chamber 1 via a carburettor 8, and the gas/fuel mixture in the combustion chamber 1 is ignited by means of an ignition apparatus 9. A cycle extension fluid, for example water, steam or the like, is introduced to the combustion chamber 1 via an injector 10. Furthermore, fuel is fed into the combustion chamber 1 via secondary injectors 11. The cycle extension fluid is supplied from a fluid reservoir 12, for example via a mixing chamber 13 in which fuel 14 and peroxide 15 can be mixed with one another, with the aid of a fluid pump 16 and via a heat exchanger 17 which may optionally be positioned in the exhaust gas line 7 to the injector 10. The cycle extension fluid may optionally be taken from fluid collecting apparatus 18, positioned in the exhaust gas line 7, instead of from the reservoir or the supply apparatus 12. An oxygen enrichment apparatus 19 or an oxygen storage tank may be positioned in the supply gas line 4, via which apparatus the supply gas can be enriched with oxygen.
The embodiment according to Figure lB differs from that according to Figure lA essentially in that there is no carburettor and in that a primary fuel injector is provided instead of an ignition apparatus 9.
This embodiment relates to an internal combustion engine with self-ignition.
Figure lC shows an embodiment of the invention which represents a turbine internal combustion engine in which supply gas is introduced into compressor turbine stages 21, 22 via the line 4, which could optionally be coupled to an intermediate cooler 23.
The combustion chambers are denoted by 24, and the cylinders by 25. Fuel is introduced into the combustion chambers 24 via fuel injectors 26. The exhaust gases from the combustion chambers are emitted W098/06935 PCT~P97/04343 via expansion turbine stages 27, 28 to the exhaust gasline 29, and from there to a heat exchanger 30, which is connected to a fluid collecting apparatus 32, which collects CEF which can be recycled, and passes it to a mixing chamber 33. Fuel 35 and peroxide 36 can be mixed in the mixing chamber 33. Furthermore, a CEF
reservoir or a supply apparatus 37 is provided, via which CEF is supplied to the mixing chamber 33. The CEF is compressed by a fluid pump 34, is preheated via heat exchangers 23 and 30, and is injected in a distributed manner via injectors 31 into the combustion chamber or chambers.
Exemplary embodiments 1 to 13 of different internal combustion piston engines are explained in the following text with reference to graphs which show pressure/volume cycles and temperature/volume cycles.
Curve (1) uses solid lines to show in each case one cycle of an internal combustion piston engine which is designed in a known manner and operates in stoichiometric conditions. Curve (2) and curve (3) use dashed and then dotted lines to show a cycle of an internal combustion piston engine according to the invention, in normal operation and in over expansion operation, and curve (4) uses dashed-dotted lines to show a conventional, sub-stoichiometric operating cycle of an internal combustion piston engine with stratified charging of a known type.
Example 1:
Figure 2A shows the pressure/volume graph, and Figure 2B the temperature/volume graph of a known piston engine with external ignition. Curve 1 applies to operation in conventional stoichiometric conditions.
Curve 2 shows a cycle of the piston engine which has been improved by injection of a cycle extension fluid according to the invention, in which case this fluid is injected in order to reduce the peak temperature which ~ W098/06935 PCT~P97/04343 is reached during the combustion expansion cycle, and nevertheless to achieve a correspondingly high pressure in the cylinders. An equivalent or lower thermodynamic efficiency, but a better mechanical efficiency, are thus achieved, which leads to an equivalent or higher efficiency, equivalent or higher engine power density, and equivalent or longer engine life. The operating conditions can be chosen such that either smaller, more effective or longer-life engines are achieved.
Example 2:
The engine in Example 1 is operated in a (partial) Atkinson cycle (overexpansion) in order to utilize the higher cylinder pressure which is available after conventional expansion. Cycle 1 is unchanged from Example 1. Cycles 2+3 show operation of the conventional piston engine with external ignition, which is modified according to the invention to use the Atkinson cycle. This leads to the cycle having a higher or equivalent thermodynamic efficiency and a higher or equivalent mechanical efficiency, which results in an equivalent or higher engine efficiency, equivalent or higher engine power density, and equivalent or longer engine life. Once again, the operating conditions can be chosen such that either smaller, more efficient, or longer-life engines are achieved.
Example 3:
A conventional piston engine with external ignition is operated sub-stoichiometrically in stratified charging conditions, improved by cycle extension fluid injection, and optionally improved by conditional fuel injection (Figure lA), in which case the cycle extension fluid is injected in order to maintain or to reduce the peak temperature which is reached during the combustion/expansion cycle, and nevertheless to achieve a correspondingly high pressure in the cylinders. The - W098/06935 PCT~P97/04343 optional additional fuel injection is used to increase the heat supplied and thus to increase the cylinder pressure; both are limited by stoichiometric conditions. In graphs 2A and 2B, the pressure/volume cycles and temperature/volume cycles 4 apply to a conventional piston engine with external ignition, which is operated sub-stoichiometrically in stratified charging conditions. The cycles 2 are modified according to the invention and are limited by stoichiometric conditions. This results in the cycle having an equivalent or lower thermodynamic efficiency, but a better mechanical efficiency, which leads to an equivalent or higher engine efficiency, equivalent or higher engine power density, and equivalent or longer engine life. The operating conditions can be chosen such that either smaller, more powerful or longer-life engines are achieved.
Example 4:
The piston engine according to Example 3 is operated using the (partial) Atkinson cycle (overexpansion) in order to utilize the advantages of the higher cylinder pressure available after expansion. The cycles 4 according to Figures 2A and 2B are based on a conventional piston engine with external ignition, which is operated sub-stoichiometrically in stratified charging conditions. Cycles 2 and 3 result from a modification of the invention using the Atkinson cycle, in which case the cycle is limited by stoichiometric conditions. This results in the cycle having higher or equivalent thermodynamic efficiency and a better or equivalent mechanical efficiency, equivalent or higher engine efficiency, equivalent or higher engine power density, and equivalent or longer engine life. The operating conditions can once again be chosen such that either smaller, more effective or longer-life engines are achieved.
W098/06935 PCT~P97/04343 Example 5:
A conventional piston engine with self-ignition is operated sub-stoichiometrically, is enhanced by cycle extension fluid injection and is optionally improved by additional fuel injection according to Figure lB, in which case cycle extension fluid is injected in order to reduce the peak temperature occurring during the combustion/expansion cycle and, nevertheless, to achieve a correspondingly high pressure in the cylinders. Additional fuel injection is optionally carried out in order to increase the heat supplied and thus the cylinder pressure; this is limited by stoichiometric conditions. The graphs in Figures 3A
and 3B show the pressure/volume cycles and temperature/volume cycles 4 of a conventional piston engine with self-ignition, which is operated with excess air. The cycles 1 in Figures 3A and 3B relate to a piston engine with external ignition, which is operated sub-stoichiometrically and in which the operating temperature is excessively high. The cycles 2 result from an embodiment of the invention which is limited by stoichiometric conditions. This leads to the cycle having an equivalent or lower thermodynamic efficiency but a better mechanical efficiency, which results in an equivalent or higher engine power, equivalent or higher engine power density, and equivalent or longer engine life. The operating conditions can be chosen such that either smaller, more effective or longer-life engines are achieved.
Example 6:
The piston engine according to Example 5 is operated using the (partial) Atkinson cycle (overexpansion) in order to utilize the advantage of higher cylinder pressure after conventional expansion. In the graphs in Figures 3A and 3B, the cycles 4 are based on a conventional piston engine with self-ignition, which is operated sub-stoichiometrically. The cycles 1 relate - W098/06935 PCT~P97/04343 to a conventional piston engine with self-ignition, which is operated stoichiometrically, and which leads to an excessively high operating temperature. The cycles 2 and 3 relate to piston engines which are modified according to the invention to use the Atkinson cycle and are limited by stoichiometric conditions.
This results in the cycle having a higher or equivalent thermodynamic efficiency and a better or equivalent mechanical efficiency, which leads to an equivalent or higher engine efficiency, equivalent or higher engine power density, and equivalent or longer engine life.
The operating conditions can be chosen such that either smaller, more efficient or longer-life engines are achieved.
Example 7:
A conventional gas or fuel turbine or steam-augmented gas or fuel turbine is always operated sub-stoichiometrically, is augmented by injection of cycle extension fluid and is assisted by additional fuel injection at high pressure, in which case the cycle extension fluid is injected in order to reduce the peak temperature reached downstream of the combustion chambers and to increase the fluid volume flowing into the next combustion chambers. This process is optionally repeated, and is finally limited by stoichiometric conditions. Such a turbine, as is illustrated in Figure lC is operated such that the temperatures of the fluid reaching the expansion turbine are reduced. Figures 4A and 4E relate to the cycles 1 of a conventional gas or fuel turbine which is operated sub-stoichiometrically, and the cycles 2 to a conventional gas or fuel turbine which is operated stoichiometrically and results in excessively high operating temperatures. The cycles 3 relate to a turbine which is modified according to the invention and is limited by stoichiometric conditions. This leads to the cycle having an equivalent or lower - W098/06935 PCT~P97/04343 thermodynamic efficiency and an equivalent or better mechanical efficiency, to an equivalent or higher turbine efficiency, equivalent or higher turbine power density and equivalent or longer turbine life. The operating conditions can be chosen such that either smaller, more effective or longer-life engines are achieved.
Example 8:
All the Examples 1-7 can be operated with an operating fluid enriched with oxygen, in order that the stoichiometric point is shifted towards higher fuel injection levels. This is combined with increased cycle extension fluid injections, in order to keep the combustion temperatures below the limits which are important for long engine life. This results in the cycle having a similar thermodynamic efficiency as well as a better or equivalent mechanical efficiency, an equivalent or higher engine efficiency, equivalent or higher engine power density, and equivalent or longer engine life. The operating conditions can be chosen such that either smaller, more efficient or longer-life engines are achieved.
Example 9:
This example represents a limiting case of the Example 8 based on one of the Examples 1-7, in which case pure oxygen is used as the operating medium in conjunction with repeated fuel injections and cycle extension fluid injections (CEF injections), in order to keep the combustion temperatures below the limits which are critical for a long engine life. The graphs 5A and 5B
relate to the cycles 4 of a conventional piston engine with external ignition, which is operated sub-stoichiometrically in stratified charging conditions.The cycles 1 relate to a conventional piston engine with external ignition, which is operated stoichiometrically with pure oxygen and which reaches - W098/06935 PCT~P97/04343 excessively high operating temperatures. The cycles 2 relate to a modification according to the invention, in which operation is carried out with pure oxygen and is limited by stoichiometric conditions. The cycles 2+3 represent operation which is modified according to the invention and operates with pure oxygen using the Atkinson cycle, in which case, once again, limiting occurs as a result of stoichiometric conditions.
In Figures 6A and 6B, the cycles (4) relate to a conventional piston engine with self-ignition, which is operated sub-stoichiometrically. The cycles (1) relate to a conventional piston engine with self-ignition, which is operated stoichiometrically with pure oxygen, which leads to an excessively high operating temperature. The cycles (2) relate to an engine which is modified according to the invention and which is operated with pure oxygen, limited by stoichiometric conditions. The cycles (2) + (3) relate to an engine which has been modified according to the invention and is operated with pure oxygen using the Atkinson cycle, limited by stoichiometric conditions.
The graphs in Figures 7A and 7B show the cycles (1) which are based on a conventional gas or fuel turbine which is operated sub-stoichiometrically. The cycles (2) relate to a conventional gas or fuel turbine, which is operated stoichiometrically with pure oxygen, which results in excessively high operating temperatures.
The cycles (3) are based on gas or fuel turbines which are modified according to the invention and are operated with pure oxygen, limited by stoichiometric conditions.
This leads to the cycle having a similar thermodynamic efficiency and a higher or equivalent mechanical efficiency, which leads to an equivalent or higher engine efficiency, equivalent or higher engine power ....
-- W098/06935 PCT~P97/04343 density, and equivalent or longer engine life. The operating conditions can be chosen such that either smaller, more effective or longer-life engines are achieved.
Example 10:
All the Examples 1-9 are operated with the addition of small amounts of, for example 0.01% H2O2, O3, organic peroxides or other oxidizing substances in the cycle extension fluid, in order to clean the exhaust gases.
If water is added as the cycle extension fluid, small amounts of H2O2 or O3 additives may be achieved simply by on-line (through-flow) electrolysis of water.
Example 11:
All the abovementioned Examples 1-10 are operated with a large amount of H202, O3, organic peroxides or other oxidizing substances being added to the cycle extension fluid, in order to increase the power density further, in that a portion of the oxidizing substance is added to the cycle.
Example 12:
All the Examples 1-11 described above are operated such that the cycle extension fluid can also be mixed with aqueous fuels or fuels which can be dispersed.
Ignition is carried out by a concentrated fuel charge, and the diluted fuel then burns in an environment of cycle extension fluid. This application is limited by the situation in which all the fuel is supplied to a cycle extension fluid base.
Example 13:
All the Examples 1-12 are provided with a recovery system for cycle extension fluid in the exhaust gas line. There are three reasons for such recovery.
Concentration of the cycle extension fluid is linked to bonding of a major portion of materials in the form of - W098/06935 PCT~P97/04343 particles and water-soluble impurities. A major portion of this is destroyed in the combustion process by feeding it back into the cycle, as a result of which additional heat is obtained and the exhaust gases are cleaned. A second reason is that the flow of the cycle extension fluid can be up to 20 times greater than the fuel flow. If one considers use in a car whose diesel oil consumption is 3 l/100 km, the engine would consume up to 60 l/100 km of cycle extension fluid. Even in the case of water, which is available all the time and is cheap, the water reservoir could be replaced by a conventional water recovery unit, just for volume and weight reasons. A third reason is the costs when expensive cycle extension fluids are used.
Figure 8 shows a typical exemplary embodiment for recovery of the CEF. This comprises a circulation pump 105, which causes the cycle extension fluid to circulate through an air cooler 106, which is followed by direct injection of the cycle extension fluid 107 into the exhaust gases 101 in a gas washer 102, in which case direct contact condensation is achieved.
The condensed cycle extension fluid is then separated in a settling tank and/or a cyclone 103. The cycle extension fluid is fed back to the storage tank 104, which is provided with an overflow 110 and an outlet 111. Exhaust gases 101 can optionally be precooled in a heat exchanger 109, which once again heats the exhaust gases 108 emitted from the cycle extension fluid.
The use of water in conjunction with ethanol was investigated, with limited success, by Gunnermann (WO
91/07579). Gunnermann used aqueous alcohols with 40 and 60% water dilution. He found that an expensive and complex platinum catalytic converter was required inside the combustion chamber in order to assist the initiation of combustion, in that the hydrogen bonds in the fuel mixture were activated. Gunnermann incorrectly interpreted the high fuel efficiency as additional release of heat, which was caused by dissociated water. A simple heat balance shows that this does not occur since the heat released from the combination of hydrogen and oxygen is equal to the heat which is absorbed in the dissociation. Only the Pt value allows ignition in mixtures which would otherwise be too damp for ignition. However, Gunnermann's engine had problems with regard to its stability, reliability and costs, and was limited to a water:fuel ratio of 1.5:1.
The use of a cycle extension fluid has been practised to a limited extent in gas turbines. The W098/06935 PCT~P97/04343 injection of steam into the combustion chamber, which was originally intended in order to reduce soot formation and to promote the combustion process, resulted in increased power emission from the turbine, and an improvement in efficiency. Further investigations by a large number of inventors lead to the so-called SAGT or Steam Augmented Gas Turbine. The SAGT operates with steam injection downstream of the combustion chamber. In this way, the temperature after combustion can be raised to a considerably higher level than the expansion turbine can withstand, and steam injection reduces the temperature back to a level which is acceptable for the expansion turbine, and converts the heat into a large volume. The SAGT has been improved further and a "CHENG point" has been defined at which the efficiency of the SAGT reaches a maximum by injecting exactly the amount of saturated steam which can be produced by heat recovery from the exhaust gases. However, the CHENG point does not correspond to stoichiometric combustion, since excess oxygen is present.
A further step was taken by Urbach & Knauss, who brought the SAGT to stoichiometric combustion conditions, and accepted a higher power density at the expense of slightly reduced efficiency. Urbach &
Knauss achieved this by operating a first combustion chamber at high pressure, followed by steam injection with subsequent expansion to an intermediate pressure.
In this way, the combustion gases were cooled both by steam injection and by partial expansion. A second combustion chamber consumed the remaining oxygen, and this was followed by steam injection and final expansion. However, Urbach & Knauss did not go beyond this development stage.
The cycle extension fluid can advantageously be used as a carrier for chemicals which promote - W098/06935 PCT~P97/04343 combustion. Additives of peroxides to the fuel were already known from Lindstrom (WO 88/03550) in order to reduce the content of CO and HC residues in the exhaust gases. The addition of peroxides to the cycle extension fluid eliminates mixing, storage and shelf-life problems with fuels which are otherwise doped with peroxide.
DE 21 27 957 B2 discloses a system for the injection of an anti-knock fluid, which may be water, in order to reduce the combustion temperature. The fluid is injected before the compression stage, so that compression energy can be saved and the risk of premature ignition (knocking) is reduced by decreasing the temperatures after compression (that is say before ignition). This contains no reference to the possible introduction of more fuel into the same cycle or to isochoric combustion. Such an engine is a conventional internal combustion engine, irrespective of stratified charging, turbo charging, an Otto-cycle, diesel cycle or comparable cycle, or whether secondary or multiple fuel injectors are present.
DE 43 01 887 A1 states, in particular, that the addition of water or some other secondary fluid is based on the use of waste heat from the traditional method for vaporization, leading to a general reduction in temperatures and thus to a reduction in the contamination with, for example, NOx. In this case, the water must either be preheated or converted into steam by reusing waste heat from the exhaust gases (which is possible within very narrow limits with gas turbines, but is in practice impossible with piston engines owing to the very high pressures and the time available for injection), or the water has to be applied in liquid form to hot surfaces within the cylinder, but without taking any heat from the burnt fuel/air mixture (also, only a very small amount).
.
- W098/06935 PCT~P97/04343 This shows that no consideration was given to the possibility of injecting more fuel per cycle.
The use of more than one fuel injector in a combustion chamber is known in the prior art, but always for purposes other than that in the present invention. Multiple injectors are typically used for pistons with very large bores, in which the aim is to reduce the size of the mixing region. According to the present invention, the reason for optionally using multiple fuel injectors is that a step-by-step combustion sequence may be desirable, which is difficult or impossible to achieve and/or to control if a single injector is used. According to the invention, different fuels may be used in different injectors so that, for example, combustion is initiated by using a high-quality fuel in the first injector, with this being followed by combustion of lower-quality fuels, or fuels mixed with water or with other chemicals, in the other injectors. The invention relates to the use of the injectors.
US 54 00 746 A discloses the use of hydrogen peroxide as an additive to conventional fuel in order to reduce the peak combustion temperature. This is necessary here since it has not been recognized that it is possible to improve the efficiency of combustion by the injection of sufficient fuel and by the timing of injection of water. This known method leads to the flame being extinguished when water is injected. The only option is oxygen enrichment or oxygen addition by the use of hydrogen peroxide. This does not cover the teaching of using additional oxygen, which is available in order to inject more fuel and to obtain more power from each cycle.
In contrast, the object of the invention is to expand the range of power density, efficiency and - 5a -DE 29 25 091 A1 discloses an open-circuit internal combustion engine, in which the combustion air is isothermically compressed within a compressor, is burnt with injected fuel, and the combustion gases are isothermically expanded before they are released isothermically. Water is injected in such a manner and in such quantities that it is evaporated during the compression of the combustion air. Injected water is not used for decreasing the combustion temperature and for increasing the amount of fuel, which is transformed by air unit; rather, water is injected concerning the amount and the manner as part of the compression cycle so that partial isothermic compression will be obtained. This is followed by an adiabatic isotropic compression up to extremely high pressure values so that the heat generated by compression will reach temperatures of more than 800~ C. Then, combustion will be carried through continuously during the expansion phase so that an approximate isothermic expansion will be obtained, whereby this part of compression corresponds to the Carnot portion of the cycle.
BE17834.DOC
1.2.991:01PM
W098/06935 PCT~P97/04343 engine life beyond the levels of conventional motors and engines.
This is achieved according to the invention, in the case of an internal combustion engine of this generic type, by the features in the characterizing part of Claim 1, and by a method having the features in the characterizing part of Claim 9. Further refinements of the invention are the subject matter of the dependent claims.
In principle, the proposal in the present invention is to use water or some other fluid which is chemically inert or can be decomposed endothermically, and to pass said fluid into the combustion chamber or chambers in order to make a greater amount of fuel available per cycle and thus to improve the operating power of internal combustion engines. The fluid used for this purpose is a secondary fluid, which is called a cycle extension fluid (CEF). This fluid makes it possible to use a similar or higher fuel/air ratio without any disadvantageous effects on the temperature/pressure graph for the engine, which is the critical factor for long engine life. In this case, high temperature is exchanged for increased pressure and/or increased volume, in that an additional substance is vaporized and/or endothermically decomposed. This substance is preferably water, since any required amounts of water are available, it is easy to handle, and presents no environmental problems whatsoever. However, other fluid additives may also be used for specific applications.
While the use of combustion air enriched with oxygen, or even of pure oxygen, or the use of secondary, oxidizing substances, such as nitro or peroxy components gives only limited advantages since, owing to the temperature limits, only a small portion W098/06935 PCT~P97/04343 of the oxidizing substance can be utilized and stoichiometric operation is precluded, the use of a CEF
achieves a major improvement since, in comparison with conventional applications, up to five times the amount of energy can be converted per cycle. An engine operating with pure oxygen can be operated without any NOX emission and with easily controllable CO2 output, which can be cleaned in a simple manner for subsequent industrial use.
According to the invention, water is injected in liquid or gaseous form into the combustion chamber in order to increase the pressure and/or the volume while the rise in the temperature of the operating fluid is slowed down, or the temperature is stabilized or reduced. This allows higher fuel/air ratios, which would otherwise lead to excessively high temperatures in the operating fluid, to the detriment of long machine life. In this case, gas, solid material or a liquid other than water may also be injected into the combustion chamber, in order to achieve the same effect as water. Such a medium should either vaporize and convert heat into a large volume or high pressure, or should result in endothermic dissociation in order to achieve a large volume or partial pressure of decomposition products. In the case of a gas turbine, the combustion takes place isobarically, and the fluid produces a large volume. In the case of a piston engine, combustion takes place partially isochorically, and the fluid produces a high pressure.
The amounts of water injected may be up to twenty times the amount of fuel used. This means that a large water reservoir or a system for recovering water from the exhaust gases is used. Since the exhaust gases are considerably cooler than was previously the case, this can be achieved using very simple means, preferably by cooling close to the dew point using dried exhaust ~ W098/06935 PCT~P97/04343 gases in a heat exchanger, followed by wet washing with further cooling in the washing water cycle. Recovered water holds a large amount of residual impurities, which can be introduced into the cycle once again, and can be burnt.
This technique allows very high power densities to be achieved since more energy can be introduced into an operating cycle for an equivalent or lower theoretical cycle efficiency, to be precise with a comparatively equivalent or better overall efficiency for conversion into mechanical energy. In the case of an engine with spark-plug ignition, a small range of materials may be used in order to achieve power densities which at the moment can be achieved, for example, only in expensive racing-car engines, with engine lives which far exceed those of conventional designs. This technique also makes it possible for engines with self-ignition to achieve equivalent or higher power densities than engines with external ignition, since the upper temperature limit is raised. In the case of gas turbines, this technique makes it possible to increase the power densities by a factor of 5 or more, since the upper temperature limit is raised (WO 94/28285). In the case of steam-augmented gas turbines, SAGT, improved efficiency can be achieved and, with engines according to Urbach & Knauss, increased power density can be achieved. The latter engines have brought the conditions for SAGT turbines up to stoichiometric combustion, but options for operating at reduced temperatures (in order to achieve the advantage of lengthened engine life) are not recognized, nor is the potential for operation with oxygen augmentation or pure oxygen exploited. Limiting the peak temperature when using fluids is important from the environmental aspect, in terms of reducing NOX emissions.
W098/06935 PCT~P97/04343 g Minor added amounts of water with, for example, 0.01~ H2~2~ O3, organic peroxides or other oxidizing substances are sufficient to clean residual CO and residual HC from the exhaust gases. The addition of peroxides to the water base overcomes storage and shelf-life problems of fuels doped with peroxide in some other way. Minor additions of H2O2 or O3 can be achieved simply by on-line electrolysis of water.
Stronger concentrations of peroxide can be used in order further to increase the power density, in that a portion of the oxidizing substance is supplied.
Engines can be operated with air enriched with oxygen or even with pure oxygen. The latter would result in no NOX whatsoever being formed, and in the exhaust gases being composed exclusively of CO2 and water. Water can be condensed and recycled, and CO2 can be used for industrial processes or for addition to the air in greenhouses or the like.
Water can also be mixed with water-soluble fuels or fuels which can be dispersed in water. The ignition process is achieved by a concentrated fuel charge, and the fuel diluted with water can then be burnt in an aqueous environment. This application is limited by the situation in which all the fuel is supplied in an aqueous base, this being equivalent to Gunnermann's proposal, which proposed aqueous alcohols in 40 and 60~
aqueous solution and required an expensive platinum catalytic converter in the combustion chamber in order to assist the initiation of combustion, in that the hydrogen bonds in the fuel mixture were activated. The high fuel efficiency for additional release of heat, which was caused by dissociated water, was not identified by Gunnermann. A simple heat balance shows that this is not true, since the heat released from the hydrogen/oxygen combination is equal to the heat absorbed in the dissociation. The Pt allows only one - W098/06935 PCT~P97/04343 ignition in mixtures which would otherwise be too wet for ignition. In this case, Gunnermann's engine ran into stability, reliability and cost problems, and was limited to a water:fuel ratio of 3:2, while considerably higher levels could be achieved with the present invention.
The invention results in the capability to operate an internal combustion engine of this generic type in a region of power density, efficiency and machine life which until now has not been feasible. This is achieved in that a fluid which extends the cycle is added, and either the amount of fuel added per cycle is increased or the cycle is modified towards higher pressures.
The invention is explained in the following text with reference to exemplary embodiments in conjunction with the drawing, in which:
Figures lA - lC show schematic illustrations of basic design embodiments of an internal combustion engine according to the invention, Figures 2 - 7 show various applications of P/V graphs (A) and T/V graphs (B) for machines according to Figures lA - lC, and 30 Figure 8 shows a specific embodiment of the invention, relating to the provision of the cycle extension fluid.
In the embodiment according to Figure lA, one or more combustion chambers 1 having cylinders 2 and a corresponding number of pistons 3 are fed with supply gas by a line 4 via inlet valves 5. The exhaust gases produced from the combustion are dissipated via outlet W098/06935 PCT~P97/04343 valves 6, through an exhaust gas line 7. Fuel is introduced to the combustion chamber 1 via a carburettor 8, and the gas/fuel mixture in the combustion chamber 1 is ignited by means of an ignition apparatus 9. A cycle extension fluid, for example water, steam or the like, is introduced to the combustion chamber 1 via an injector 10. Furthermore, fuel is fed into the combustion chamber 1 via secondary injectors 11. The cycle extension fluid is supplied from a fluid reservoir 12, for example via a mixing chamber 13 in which fuel 14 and peroxide 15 can be mixed with one another, with the aid of a fluid pump 16 and via a heat exchanger 17 which may optionally be positioned in the exhaust gas line 7 to the injector 10. The cycle extension fluid may optionally be taken from fluid collecting apparatus 18, positioned in the exhaust gas line 7, instead of from the reservoir or the supply apparatus 12. An oxygen enrichment apparatus 19 or an oxygen storage tank may be positioned in the supply gas line 4, via which apparatus the supply gas can be enriched with oxygen.
The embodiment according to Figure lB differs from that according to Figure lA essentially in that there is no carburettor and in that a primary fuel injector is provided instead of an ignition apparatus 9.
This embodiment relates to an internal combustion engine with self-ignition.
Figure lC shows an embodiment of the invention which represents a turbine internal combustion engine in which supply gas is introduced into compressor turbine stages 21, 22 via the line 4, which could optionally be coupled to an intermediate cooler 23.
The combustion chambers are denoted by 24, and the cylinders by 25. Fuel is introduced into the combustion chambers 24 via fuel injectors 26. The exhaust gases from the combustion chambers are emitted W098/06935 PCT~P97/04343 via expansion turbine stages 27, 28 to the exhaust gasline 29, and from there to a heat exchanger 30, which is connected to a fluid collecting apparatus 32, which collects CEF which can be recycled, and passes it to a mixing chamber 33. Fuel 35 and peroxide 36 can be mixed in the mixing chamber 33. Furthermore, a CEF
reservoir or a supply apparatus 37 is provided, via which CEF is supplied to the mixing chamber 33. The CEF is compressed by a fluid pump 34, is preheated via heat exchangers 23 and 30, and is injected in a distributed manner via injectors 31 into the combustion chamber or chambers.
Exemplary embodiments 1 to 13 of different internal combustion piston engines are explained in the following text with reference to graphs which show pressure/volume cycles and temperature/volume cycles.
Curve (1) uses solid lines to show in each case one cycle of an internal combustion piston engine which is designed in a known manner and operates in stoichiometric conditions. Curve (2) and curve (3) use dashed and then dotted lines to show a cycle of an internal combustion piston engine according to the invention, in normal operation and in over expansion operation, and curve (4) uses dashed-dotted lines to show a conventional, sub-stoichiometric operating cycle of an internal combustion piston engine with stratified charging of a known type.
Example 1:
Figure 2A shows the pressure/volume graph, and Figure 2B the temperature/volume graph of a known piston engine with external ignition. Curve 1 applies to operation in conventional stoichiometric conditions.
Curve 2 shows a cycle of the piston engine which has been improved by injection of a cycle extension fluid according to the invention, in which case this fluid is injected in order to reduce the peak temperature which ~ W098/06935 PCT~P97/04343 is reached during the combustion expansion cycle, and nevertheless to achieve a correspondingly high pressure in the cylinders. An equivalent or lower thermodynamic efficiency, but a better mechanical efficiency, are thus achieved, which leads to an equivalent or higher efficiency, equivalent or higher engine power density, and equivalent or longer engine life. The operating conditions can be chosen such that either smaller, more effective or longer-life engines are achieved.
Example 2:
The engine in Example 1 is operated in a (partial) Atkinson cycle (overexpansion) in order to utilize the higher cylinder pressure which is available after conventional expansion. Cycle 1 is unchanged from Example 1. Cycles 2+3 show operation of the conventional piston engine with external ignition, which is modified according to the invention to use the Atkinson cycle. This leads to the cycle having a higher or equivalent thermodynamic efficiency and a higher or equivalent mechanical efficiency, which results in an equivalent or higher engine efficiency, equivalent or higher engine power density, and equivalent or longer engine life. Once again, the operating conditions can be chosen such that either smaller, more efficient, or longer-life engines are achieved.
Example 3:
A conventional piston engine with external ignition is operated sub-stoichiometrically in stratified charging conditions, improved by cycle extension fluid injection, and optionally improved by conditional fuel injection (Figure lA), in which case the cycle extension fluid is injected in order to maintain or to reduce the peak temperature which is reached during the combustion/expansion cycle, and nevertheless to achieve a correspondingly high pressure in the cylinders. The - W098/06935 PCT~P97/04343 optional additional fuel injection is used to increase the heat supplied and thus to increase the cylinder pressure; both are limited by stoichiometric conditions. In graphs 2A and 2B, the pressure/volume cycles and temperature/volume cycles 4 apply to a conventional piston engine with external ignition, which is operated sub-stoichiometrically in stratified charging conditions. The cycles 2 are modified according to the invention and are limited by stoichiometric conditions. This results in the cycle having an equivalent or lower thermodynamic efficiency, but a better mechanical efficiency, which leads to an equivalent or higher engine efficiency, equivalent or higher engine power density, and equivalent or longer engine life. The operating conditions can be chosen such that either smaller, more powerful or longer-life engines are achieved.
Example 4:
The piston engine according to Example 3 is operated using the (partial) Atkinson cycle (overexpansion) in order to utilize the advantages of the higher cylinder pressure available after expansion. The cycles 4 according to Figures 2A and 2B are based on a conventional piston engine with external ignition, which is operated sub-stoichiometrically in stratified charging conditions. Cycles 2 and 3 result from a modification of the invention using the Atkinson cycle, in which case the cycle is limited by stoichiometric conditions. This results in the cycle having higher or equivalent thermodynamic efficiency and a better or equivalent mechanical efficiency, equivalent or higher engine efficiency, equivalent or higher engine power density, and equivalent or longer engine life. The operating conditions can once again be chosen such that either smaller, more effective or longer-life engines are achieved.
W098/06935 PCT~P97/04343 Example 5:
A conventional piston engine with self-ignition is operated sub-stoichiometrically, is enhanced by cycle extension fluid injection and is optionally improved by additional fuel injection according to Figure lB, in which case cycle extension fluid is injected in order to reduce the peak temperature occurring during the combustion/expansion cycle and, nevertheless, to achieve a correspondingly high pressure in the cylinders. Additional fuel injection is optionally carried out in order to increase the heat supplied and thus the cylinder pressure; this is limited by stoichiometric conditions. The graphs in Figures 3A
and 3B show the pressure/volume cycles and temperature/volume cycles 4 of a conventional piston engine with self-ignition, which is operated with excess air. The cycles 1 in Figures 3A and 3B relate to a piston engine with external ignition, which is operated sub-stoichiometrically and in which the operating temperature is excessively high. The cycles 2 result from an embodiment of the invention which is limited by stoichiometric conditions. This leads to the cycle having an equivalent or lower thermodynamic efficiency but a better mechanical efficiency, which results in an equivalent or higher engine power, equivalent or higher engine power density, and equivalent or longer engine life. The operating conditions can be chosen such that either smaller, more effective or longer-life engines are achieved.
Example 6:
The piston engine according to Example 5 is operated using the (partial) Atkinson cycle (overexpansion) in order to utilize the advantage of higher cylinder pressure after conventional expansion. In the graphs in Figures 3A and 3B, the cycles 4 are based on a conventional piston engine with self-ignition, which is operated sub-stoichiometrically. The cycles 1 relate - W098/06935 PCT~P97/04343 to a conventional piston engine with self-ignition, which is operated stoichiometrically, and which leads to an excessively high operating temperature. The cycles 2 and 3 relate to piston engines which are modified according to the invention to use the Atkinson cycle and are limited by stoichiometric conditions.
This results in the cycle having a higher or equivalent thermodynamic efficiency and a better or equivalent mechanical efficiency, which leads to an equivalent or higher engine efficiency, equivalent or higher engine power density, and equivalent or longer engine life.
The operating conditions can be chosen such that either smaller, more efficient or longer-life engines are achieved.
Example 7:
A conventional gas or fuel turbine or steam-augmented gas or fuel turbine is always operated sub-stoichiometrically, is augmented by injection of cycle extension fluid and is assisted by additional fuel injection at high pressure, in which case the cycle extension fluid is injected in order to reduce the peak temperature reached downstream of the combustion chambers and to increase the fluid volume flowing into the next combustion chambers. This process is optionally repeated, and is finally limited by stoichiometric conditions. Such a turbine, as is illustrated in Figure lC is operated such that the temperatures of the fluid reaching the expansion turbine are reduced. Figures 4A and 4E relate to the cycles 1 of a conventional gas or fuel turbine which is operated sub-stoichiometrically, and the cycles 2 to a conventional gas or fuel turbine which is operated stoichiometrically and results in excessively high operating temperatures. The cycles 3 relate to a turbine which is modified according to the invention and is limited by stoichiometric conditions. This leads to the cycle having an equivalent or lower - W098/06935 PCT~P97/04343 thermodynamic efficiency and an equivalent or better mechanical efficiency, to an equivalent or higher turbine efficiency, equivalent or higher turbine power density and equivalent or longer turbine life. The operating conditions can be chosen such that either smaller, more effective or longer-life engines are achieved.
Example 8:
All the Examples 1-7 can be operated with an operating fluid enriched with oxygen, in order that the stoichiometric point is shifted towards higher fuel injection levels. This is combined with increased cycle extension fluid injections, in order to keep the combustion temperatures below the limits which are important for long engine life. This results in the cycle having a similar thermodynamic efficiency as well as a better or equivalent mechanical efficiency, an equivalent or higher engine efficiency, equivalent or higher engine power density, and equivalent or longer engine life. The operating conditions can be chosen such that either smaller, more efficient or longer-life engines are achieved.
Example 9:
This example represents a limiting case of the Example 8 based on one of the Examples 1-7, in which case pure oxygen is used as the operating medium in conjunction with repeated fuel injections and cycle extension fluid injections (CEF injections), in order to keep the combustion temperatures below the limits which are critical for a long engine life. The graphs 5A and 5B
relate to the cycles 4 of a conventional piston engine with external ignition, which is operated sub-stoichiometrically in stratified charging conditions.The cycles 1 relate to a conventional piston engine with external ignition, which is operated stoichiometrically with pure oxygen and which reaches - W098/06935 PCT~P97/04343 excessively high operating temperatures. The cycles 2 relate to a modification according to the invention, in which operation is carried out with pure oxygen and is limited by stoichiometric conditions. The cycles 2+3 represent operation which is modified according to the invention and operates with pure oxygen using the Atkinson cycle, in which case, once again, limiting occurs as a result of stoichiometric conditions.
In Figures 6A and 6B, the cycles (4) relate to a conventional piston engine with self-ignition, which is operated sub-stoichiometrically. The cycles (1) relate to a conventional piston engine with self-ignition, which is operated stoichiometrically with pure oxygen, which leads to an excessively high operating temperature. The cycles (2) relate to an engine which is modified according to the invention and which is operated with pure oxygen, limited by stoichiometric conditions. The cycles (2) + (3) relate to an engine which has been modified according to the invention and is operated with pure oxygen using the Atkinson cycle, limited by stoichiometric conditions.
The graphs in Figures 7A and 7B show the cycles (1) which are based on a conventional gas or fuel turbine which is operated sub-stoichiometrically. The cycles (2) relate to a conventional gas or fuel turbine, which is operated stoichiometrically with pure oxygen, which results in excessively high operating temperatures.
The cycles (3) are based on gas or fuel turbines which are modified according to the invention and are operated with pure oxygen, limited by stoichiometric conditions.
This leads to the cycle having a similar thermodynamic efficiency and a higher or equivalent mechanical efficiency, which leads to an equivalent or higher engine efficiency, equivalent or higher engine power ....
-- W098/06935 PCT~P97/04343 density, and equivalent or longer engine life. The operating conditions can be chosen such that either smaller, more effective or longer-life engines are achieved.
Example 10:
All the Examples 1-9 are operated with the addition of small amounts of, for example 0.01% H2O2, O3, organic peroxides or other oxidizing substances in the cycle extension fluid, in order to clean the exhaust gases.
If water is added as the cycle extension fluid, small amounts of H2O2 or O3 additives may be achieved simply by on-line (through-flow) electrolysis of water.
Example 11:
All the abovementioned Examples 1-10 are operated with a large amount of H202, O3, organic peroxides or other oxidizing substances being added to the cycle extension fluid, in order to increase the power density further, in that a portion of the oxidizing substance is added to the cycle.
Example 12:
All the Examples 1-11 described above are operated such that the cycle extension fluid can also be mixed with aqueous fuels or fuels which can be dispersed.
Ignition is carried out by a concentrated fuel charge, and the diluted fuel then burns in an environment of cycle extension fluid. This application is limited by the situation in which all the fuel is supplied to a cycle extension fluid base.
Example 13:
All the Examples 1-12 are provided with a recovery system for cycle extension fluid in the exhaust gas line. There are three reasons for such recovery.
Concentration of the cycle extension fluid is linked to bonding of a major portion of materials in the form of - W098/06935 PCT~P97/04343 particles and water-soluble impurities. A major portion of this is destroyed in the combustion process by feeding it back into the cycle, as a result of which additional heat is obtained and the exhaust gases are cleaned. A second reason is that the flow of the cycle extension fluid can be up to 20 times greater than the fuel flow. If one considers use in a car whose diesel oil consumption is 3 l/100 km, the engine would consume up to 60 l/100 km of cycle extension fluid. Even in the case of water, which is available all the time and is cheap, the water reservoir could be replaced by a conventional water recovery unit, just for volume and weight reasons. A third reason is the costs when expensive cycle extension fluids are used.
Figure 8 shows a typical exemplary embodiment for recovery of the CEF. This comprises a circulation pump 105, which causes the cycle extension fluid to circulate through an air cooler 106, which is followed by direct injection of the cycle extension fluid 107 into the exhaust gases 101 in a gas washer 102, in which case direct contact condensation is achieved.
The condensed cycle extension fluid is then separated in a settling tank and/or a cyclone 103. The cycle extension fluid is fed back to the storage tank 104, which is provided with an overflow 110 and an outlet 111. Exhaust gases 101 can optionally be precooled in a heat exchanger 109, which once again heats the exhaust gases 108 emitted from the cycle extension fluid.
Claims (22)
1. Method for operating reciprocating internal combustion engines of the diesel engine or Otto-cycle engine type, or of a turbine engine, or combinations thereof, in which fuel is burnt in a combustion chamber to which the fuel is supplied via a feed gas inlet with an inlet valve or valves, and from which the combustion gases are carried away via a gas outlet with an outlet valve or valves, characterized in that, in addition to conventionally used fuel, a cycle extension fluid (CEF) in the form of water or some other fluid which is chemically inert or can be decomposedendothermically is injected into the combustion chamber in order to allow a greater quantity of fuel to be used per cycle, in which case, at the same time, the temperature and pressure remain linked to longer engine life, in that high temperature is exchanged for high pressure and/or high volume by the cycle extension fluid being vaporized or chemically decomposed, and that when using water as the cycle extension fluid the water injection values are between 1.5 times and 20 times the amount of the entire used fluid.
2. Method according to Claim 1, characterized in that the internal combustion engine has external ignition and is operated with conventional stoichiometric conditions, linked to injection of the cycle extension fluid, and in that the peak temperature which is reached during the combustion expansion cycle is reduced by injection of the cycle extension fluid, and a correspondingly high pressure is nevertheless achieved in the cylinders.
3. Method according to one of Claims 1 or 2, characterized in that the internal combustion engine is operated in sub-stoichiometric, stratified charging conditions, reinforced by the cycle extension fluid, and optionally with additional fuel injec-tion, in which case the cycle extension fluid is injected in order tomaintain or to reduce the peak temperature reached during the combustion expansion cycle, and nevertheless to achieve a corresponding pressure in the cylinders.
4. Method according to one of Claims 1 - 3, characterized in that cycle extension fluid is injected in a conventional piston engine with self-ignition which is operated sub-stoichiometrically, and in that additional fuel injection is optionally carried out, in which case the cycle extension fluid is injected in order to reduce the peak temperature reached during the combustion expansion cycle, and nevertheless to achieve a correspondingly high pressure in the cylinders.
5. Method according to Claim 2, 3 or 4, characterized in that optional additional fuel injection is carried out in order further to increase the energy supply and thus the cylinder pressure, limited by the stoichiometric conditions.
6. Method according to Claim 2, 3, 4 or 5, characterized in that Atkinson cylce (over-expansion) operation is used, and in that the higher cylinder pressure available after conventional expansion is utilized.
7. Method according to Claim 1 in conjunction with conventional gas or fuel turbines or gas or fuel turbines with steam assistance, which are always operated sub-stoichiometrically, characterized in that cycle extension fluid is injected and in that additional fuel is injected at high pressure, in which case the cycle extension fluid is injected in order to reduce the peak temperature reached downstream of the combustion chambers and to increase the fluid volume flowing into the next combustion chambers, this process is optionally repeated and, finally, is limited only by stoichiometric conditions.
8. Method according to one of Claims 1 - 7, characterized in that operation is carried out with operating fluid enriched with oxygen, so that the stoichiometric point is shifted to higher fuel injection levels, in which case increased cycle extensionfluid injection is optionally carried out in order to keep combustion temperatures below the limits that are critical to long engine life.
9. Method according to Claim 8, characterized in that pure oxygen in conjunctionwith repeated fuel injection and cycle fluid extension injection is used as the operating fluid, in order to keep the combustion temperatures below the limits that are critical to long engine life.
10. Method according to one of Claims 1 - 9, characterized in that a weak additive with, for example 0.01% H2O2, O3, organic peroxides or other oxidizing substances is/are added to the cycle extension fluid in order to clean the exhaust gases.
11. Method according to one of Claims 1 - 10, characterized in that a strong additive of H2O2, O3, organic peroxide or other oxidizing substances is/are added to the cycle extension fluid in order to improve the increase in the power density, in which case a portion of the oxidizing substance is introduced via the CEF as a carrier into the cycle.
12. Method according to one of Claims 1 - 11, characterized in that the cycle extension fluid has soluble or dispersing fuels added to it, in that ignition is carried out by a concentrated fuel charge, and in that the thinned fuel is then burnt in an environment of cycle extension fluid.
13. Method according to one of Claims 1 - 12, characterized in that a cycle extension fluid recovery system is used in the exhaust gas line, in which the cycle extension fluid is condensed, a major portion of the impurities which are in the form of particles and are soluble in fluid is rendered non-hazordous and a considerable por- tion of said impurities is destroyed in the combustion process by recovering them into the cycle.
14. Internal combustion engine with external ignition for carrying through the method according to any of Claims 1 - 13, comprising a) at least one operating or combustion chamber (1) having a reciprocatingly or rotatingly driven piston/cylinder system (2, 3), b) supply means (4, 8) for feeding primary fuel, such as gasoline, diesel, fuel gas or equivalent fuel by means of a carburretor (8), c) supply means (4) for feeding gas, such as air and/or corresponding type of gas supporting the combustion process, with an inlet valve or valves (5) into the combustion chamber (1), d) ignition means (9) for time-controlled igniting the compressed fuel/gas mixture into the combustion chamber (1), e) exhaust gas means (6, 7) with outlet means (6) and an exhaust gas line (7), characterized by f) supply means (12, 13, 16, 17, 10) for feeding a cycle extension fluid (CEF) in liquid, gaseous or mixed form into the combustion chamber (1) by means of an injector (10) which is designed in such a manner that when using water as CEF the water injection values are between 1.5 times and 20 times the amount of the entire used fuel, g) additional supply means (11) for feeding additional amounts of secondary fuelinto the combustion chamber (1) by means of secondary injectors (11), and h) a motor managing system for time-controlling the ignition and injection peri ods as well the injection amounts according to the actual load conditions.
15. Internal combustion engine with self-ignition for carrying through the method according to any of Claims 1 - 13, comprising a) at least one operating or combustion chamber (1) having a reciprocatingly or rotatingly driven piston/cylinder system (2, 3), b) supply means (4, 8) for feeding primary fuel, such as diesel fuel or equivalent fuel, c) supply means (4) for feeding gas, such as air and/or corresponding type of gas supporting the combustion process, with an inlet valve or valves (5) into the combustion chamber (1), d) exhaust gas means (6, 7) with outlet means (6) and an exhaust gas line (7), characterized by e) supply means (12, 13, 16, 17, 10) for feeding a cycle extension fluid (CEF) in liquid, gaseous or mixed form into the combustion chamber (1) by means of an injector (10) which is designed in such a manner that when using water as CEF the water injection values are between 1.5 fold and the 20 fold amount of the totally used fuel, f) an additional feeding means (11) for feeding additional amounts of secondary fuel into the combustion chamber (1) by means of secondary injectors (11), and g) a motor managing system for time-controlling the ignition and injection timesas well the injection amounts according to the actual load conditions.
16. Turbine combustion engine for carrying through the method according to any of Claims 1 - 13, comprising a) at least one combustion chamber (24), in which the compression is generated by one-stage or multi-stage rotating turbines (21, 22) and the expansion (energy recovering) is generated by means of one-stage or multi-stage rotating turbines (27, 28), b) first supply means (26) for feeding primary fuel in the form of gasoline, oil, gas or the like, by mixing means, c) supply means (4) for feeding gas, such as air and/or a corresponding gas supporting the combustion process, by means of adjustable inlet guide vanes into the first stage, separated from the combustion chamber by the compression turbine (21, 22), d) first ignition means (9) for igniting the compressed fuel gas mixture within the combustion chamber, e) exhaust gas means (29), separated from the combustion chamber by the expansion turbines (27, 28), characterized by f) supply means (37,33,34,23,30,31) for feeding a cycle extension fluid (CEF) in liquid, gaseous or mixed form into the combustion chamber (24) within or outside the combusion zone, by means of at least one injector, which is designed so that the water injection values are between 1.5 times and 20 times of the amount of the entire used fuel, and g) at least an additional combustion chamber (24) with supply means for feeding additional amounts of secondary fuel into the combustion chamber (26) through secondary injectors, with ignition means (9).
17. Combustion engine according to one of Claims 14,15 or 16, characterized in that the supply means (10, 31) for CEF is fed through an injection pump (16,34) from a CEF mixing chamber (13,33).
18. Combustion engine according to one of Claims 14 - 17, characterized in that CEF
is supplied from the CEF supply (12,37) through a mixing chamber (13,33) which is provided with peroxide (15,36) and fuel (14,35), and optionally through a heat exchanger (17,30).
is supplied from the CEF supply (12,37) through a mixing chamber (13,33) which is provided with peroxide (15,36) and fuel (14,35), and optionally through a heat exchanger (17,30).
19. Combustion engine according to one of Claims 14 - 18, characterized in that in the inlet (5) is provided at least with one compressor turbine (21,22), and the outlet (6) at least with one expansion turbine (27,28).
20. Combustion engine according to one of Claims 14 - 19, characterized in that for pre-heating the cycle extension fluid (CEF) a supply gas intermediate cooler (23) and/or a heat exchanger (17,30) is provided.
21. Combustion engine according to one of Claims 14 - 20, characterized in that additional fuel injectors (11) are provided within the combustion chamber (1) inorder to supply additional energy to the cycle.
22. Combustion engine according to one of Claims 14 - 21, characterized in that the air sucked into the gas inlet (4) is added with combustion air enriched by oxygen or with pure oxygen.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19632179A DE19632179A1 (en) | 1996-08-09 | 1996-08-09 | Internal combustion engine with extended duty cycle |
| DE19632179.4 | 1996-08-09 | ||
| PCT/EP1997/004343 WO1998006935A1 (en) | 1996-08-09 | 1997-08-08 | Internal combustion engine with extended working cycle |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2262980A1 true CA2262980A1 (en) | 1998-02-19 |
Family
ID=7802233
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002262980A Abandoned CA2262980A1 (en) | 1996-08-09 | 1997-08-08 | Internal combustion engine with extended working cycle |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP0917620B1 (en) |
| AT (1) | ATE193094T1 (en) |
| AU (1) | AU725076B2 (en) |
| CA (1) | CA2262980A1 (en) |
| DE (2) | DE19632179A1 (en) |
| WO (1) | WO1998006935A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113389624A (en) * | 2021-06-11 | 2021-09-14 | 重庆大学 | Wankel engine and high-temperature water spraying based tail gas waste heat recovery efficient engine structure |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102011107541B4 (en) * | 2011-07-11 | 2013-05-08 | Bruno Rettich | Increasing the efficiency of a stationary or mobile combustion engine by a closed combustion process |
| DE102016112735A1 (en) * | 2016-07-12 | 2018-01-18 | Ingo Kolsch | Method and device for improving the combustion process, in particular in an internal combustion engine |
| WO2022175718A1 (en) * | 2021-02-18 | 2022-08-25 | Al Mahmood Fouad | A process minimizes nitrogen oxides emitted from reciprocating internal combustion engine applications and maximizing efficiency. |
Family Cites Families (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2094565A5 (en) * | 1970-06-25 | 1972-02-04 | Loby Gilbert | |
| GB1531492A (en) * | 1975-10-14 | 1978-11-08 | Lindberg J | Pollution control |
| DE2925091A1 (en) * | 1979-06-21 | 1981-01-08 | Vinko Dipl Ing Mucic | Open cycle gas turbine engine - has water and fuel injected in stages to give isothermal compression and expansion |
| DE2926970A1 (en) * | 1979-07-04 | 1981-01-15 | Wilhelm Haeberle | Reciprocating IC engine with water injection - has regenerative heat exchanger in exhaust valve port to raise steam to increase output |
| US4508064A (en) * | 1981-11-12 | 1985-04-02 | Katsuji Baba | Internal combustion engine of hydrogen gas |
| JPS60166746A (en) * | 1984-02-09 | 1985-08-30 | Kuraray Co Ltd | Combustion of diesel internal-combustion engine |
| SE8502388L (en) | 1985-05-14 | 1986-11-15 | Arne Johannes Lindstrom | SET AND LIQUID COMPOSITION FOR OPTIMIZATION OF FUEL COMBUSTION TO ENGINES AND BOILERS |
| KR0140975B1 (en) | 1989-11-22 | 1998-07-01 | 더블유. 군너만 루돌프 | Aqueous fuel for internal combustion engine and method of combustion |
| DE4301887A1 (en) * | 1993-01-14 | 1994-07-21 | Struck Wilfried | Gas-steam-process for IC engine |
| US5329758A (en) | 1993-05-21 | 1994-07-19 | The United States Of America As Represented By The Secretary Of The Navy | Steam-augmented gas turbine |
| US5400746A (en) * | 1993-06-21 | 1995-03-28 | Odex, Inc. | Internal combustion |
| DE29512280U1 (en) * | 1995-07-29 | 1995-09-28 | Rau, Rupert, 72393 Burladingen | Device for driving a shaft |
-
1996
- 1996-08-09 DE DE19632179A patent/DE19632179A1/en not_active Ceased
-
1997
- 1997-08-08 WO PCT/EP1997/004343 patent/WO1998006935A1/en active IP Right Grant
- 1997-08-08 AU AU39431/97A patent/AU725076B2/en not_active Ceased
- 1997-08-08 CA CA002262980A patent/CA2262980A1/en not_active Abandoned
- 1997-08-08 DE DE59701732T patent/DE59701732D1/en not_active Expired - Fee Related
- 1997-08-08 AT AT97936696T patent/ATE193094T1/en not_active IP Right Cessation
- 1997-08-08 EP EP97936696A patent/EP0917620B1/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113389624A (en) * | 2021-06-11 | 2021-09-14 | 重庆大学 | Wankel engine and high-temperature water spraying based tail gas waste heat recovery efficient engine structure |
Also Published As
| Publication number | Publication date |
|---|---|
| AU3943197A (en) | 1998-03-06 |
| DE19632179A1 (en) | 1998-02-12 |
| ATE193094T1 (en) | 2000-06-15 |
| DE59701732D1 (en) | 2000-06-21 |
| WO1998006935A1 (en) | 1998-02-19 |
| AU725076B2 (en) | 2000-10-05 |
| EP0917620B1 (en) | 2000-05-17 |
| EP0917620A1 (en) | 1999-05-26 |
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