GB2203495A - A jet propulsion unit and adaptations thereof - Google Patents

Abstract

A jet propulsion unit comprises an air compressor 1 delivering compressed air into a chamber 3 in which a steam generator 4 is positioned and heated by said compressed air, which finally leaves said chamber through a nozzle 11 and exerts a reactive thrust. The steam from said generator is fed to a turbine 5, which is the driving means of said air compressor, exhausting into a condenser 6 from which condensate liquid is pumped by pump 8 back into said steam generator. A ducted fan 14 may be driven by a shaft 15. Also an engine 17, such as a two or four stroke rotary valve, compression ignition oil engine may be provided. A gearbox 13 may be provided for power take-off purposes and an electric motor may be provided for starting. Various other adaptations are described. <IMAGE>

Description

A JET PROPULSION UNIT AND ADAPTATIONS THEREOF Thermal engines employing the working cycle disclosed in my patent specification GB 2086483B generate power by steam or mixed steam and compressed "primary" fluid formation at a critical temperature level, utilizing the heat of compressed primary fluid to vaporize a liquid secondary medium. Such engines have the advantage that, under continuous working conditions, no additional heat input is necessary.

This working cycle is used by the engines constituting my present invention.

With this invention, air or a similar fluid is compressed by a rotary or a rotary cum jet type compressor system and thereafter heats a flash steam boiler before further utilization, for example in driving a turbine or producing a propulsive thrust reaction. Steam generated by the flash boiler drives the heating fluid compressor or its rotary part, through a condensing engine coupled to said compressor or rotary portion, in the basic apparatus, but an auxiliary compressor driving means may be provided.

In a ducted fan jet propulsion unit embodiment of this invention, the main or/and the auxiliary heating fluid compressor driving means also drives a propulsive fan or the rotation of said fan is effected by a separate engine, such as a rotary vane power unit working according to my aforementioned patent specification.

Adaptations of jet propulsion units in accord with the invention include closed or open circuit turbine engines, air compression plants and combined such devices.

According to a basic aspect of the invention, a jet propulsion unit primarily comprises an axial flow rotary or rotary cum jet type heating air compressor, a connected chamber receiving the compressed heating air from said compresosr and containing a flash steam boiler heated by said compressed air, a means fed with high pressure steam by said flash boiler to drive said compressor or its rotary part, an exit for the spent compressed heating air directed through said chamber, and a condensing provision for the low pressure steam exhausting from said compressor or rotary part driving means.

According to another aspect of the invention, a jet propulsion unit of the kind described above includes a fan displacing propulsive air and driven, when so acting, for example by the steam boiler heating air compressor driving means or a separate engine.

According to a third aspect of the invention, an auxiliary driving means is provided to help rotate the steam boiler heating fluid compressor or its rotary part or/and the air displacing fan described above.

According to a fourth aspect of the invention, the basic jet propulsion unit described above is adapted to function exclusively or partly as a fluid compression plant, a heating, refrigeration or freezing or gas liquefaction plant or a gas or air pump.

According to a final aspect of the invention, a jet propulsion unit as defined anywhere above includes a mechanical power generating means fed with the spent compressed heating medium leaving the steam boiler containing chamber or provision.

The invention will now be described more precisely with reference to the accompanying drawings, in which: Fig. iisadiagrammatic axial part-section of a thermal engine according to the invention.

Fig. 2 is a diagrammatic axial part-section of a detail modification relating to Fig. 1.

Referring to Fig. 1, the engine illustrated comprises an axial flow multistage rotary air compressor 1 acting to draw ambient air through an entraining tube 2 extending forward from its (said compressor's) air intake, to compress said air and deliver it into a cylindrical chamber 3 (extending rearward from said compressor's air delivery end) in which a flash steam boiler 4 is positioned and heated by said compressed air, a turbine 5 fed with high pressure steam by said boiler and driving said air compressor 1, viz. its rotor, a condenser 6 constructed in the form of jacket around said tube 2 and cooled by the air drawn through said tube, receiving through a pipe 7 the exhaust steam from said turbine, a pump 8 feeding condensate liquid from condenser 6 via a drain sump 9 into the rear end of boiler 4, a regulator 10 for controlling the supply of condensate to said pump, and an exit nozzle 11, with which the rear end of chamber 3 is provided, for the used boiler heating air.

The top half of the figure also includes circumferential heat conducting fins 12 disposed on the outer surface of tube 2 inside condenser 6, and these fins, which are an optional feature, might, by extension at regular points so as not to obstruct the flow of exhaust steam into said condenser, help support the outer wall of said latter device against external air pressure.

The steam turbine 5 further provides, through a gearbox 13, power to drive ancillary equipment such as an electric generator, and condensate pump 8.

The compressed air exhausted through exit nozzle 11 is utilized, as required, either to exert a reactive thrust, as in a jet propulsion unit installation, to drive a power generator, for example a turbine, in a heat-exchanger conducting remaining heat from said air; for refrigeration or freezing purposes, remotely as in an air compressor plant, or in combinations of these ways, or is e.g. merely pumped air or partly or entirely liquefied.

A mechanical power generator operated by the compressed air leaving nozzle 11 may function as an auxiliary engine helping to drive for example air compressor 1 or, in a purely mechanical power producing plant, as the main power output engine.

In closed system and pumping plants the primary fluid feeding compressor 1 may be another medium, for example respectively an inert gas or natural gas, or may be steam exhausting from turbine 5 in particular installations to be fully described later.

A ducted fan 14 driven by steam turbine 5 through an extension shaft 15 and displacing extra propulsion air rearwards is included in a refined jet propulsion unit version of the basic plant, additional cooling fins 16 exposed to said displaced air stream possibly helping to cool condenser 6 in this engine. Alternatively, such a fan is driven by for example a turbine constituting an auxiliary engine, rotated by the compressed air leaving nozzle 11 or by both such a turbine and steam turbine 5 or by a separate engine 17, a long shaft passing through a hollow turbine (5) and air compressor (1) shaft or shafts being the connecting means of said fan and its driver in the first instance.

Preferably the separate engine 17 is an adapted two or four-stroke internal combustion rotary vane compression ignition oil engine working according to the same thermodynamic cycle as that disclosed in my aforementioned patent specification, "secondary fluid" liquid being supplied to said engine instead of fuel and a condensing provision for the produced (exhaust) steam being incorporated. Such a condensing means may consist of a vessel into which the exhaust mixture (secondary fluid steam and used primary fluid) leaving said engine is expanded adiabatically and its steam content condensed, both said primary fluid, which is compressed in the engine and provides the heat to vaporize the liquid secondary fluid injected into it, and said condensate being continuously recycled in this design, which is the preferred operating method and construction of this engine.The primary fluid is air or another gas in this case and the exhaust mixture could exit from this engine via a common exhaust/inlet port into the condenser vessel. In another system the primary fluid used is recycled exhaust steam.

The condensate feed to boiler 4 is carried out in chosen examples, by an automatic injector operated by high pressure steam supplied to said injector by said boiler, instead of by pump 8, or by an exhaust injector.

Optionally the basic power plant (Fig. 1) functions exclusively as a steam turbine engine, surplus power being taken off from turbine 5 e.g. through gear-box 13, or a combined method of working including an auxiliary engine driven by waste boiler heating air is used.

It may be advantageous to employ a condenser cooled by the air expanded through nozzle 11 instead of or in combination with condenser 6 to liquefy the exhaust steam of turbine 5.

Referring now also to Fig. 2, the nozzle 11 bears the same reference numeral in both figures and in said Fig. 2 communicates at its outlet with a jet or tail pipe 18 and the air expanded through said nozzle expands further through said pipe and serves as the coolant of a condenser jacket 19 provided around said pipe and fed with the exhaust steam from turbine 5 (Fig. 1). The condensate liquid drains from jacket 19 into a sump 20 before its passage to pump 8 (Fig. 1) and the spent cooling air is finally ejected from the outlet end of pipe 18, e.g. to exert thrust. If condenser 19 is used in combination with the similar device 6, only a portion of the exhaust steam of turbine 5 is passed to each said condenser.

A reservoir or liquid 21 Fig. 1 maintains the level of secondary fluid in the steam condenser(s) and a constant flow of such liquid to pump 8 and incorporates a filler 21a.

If desired, the condensers 6 and 19 may be replaced by such devices of, for example, coiled tube or multitubular design.

An embodied mechanical power generator or heat-exchanger could to advantage be positioned to receive, in the Fig. 2 plant arrangement, the (hot) air exhausting via tail pipe 18.

Refrigerative exhaust steam condensing may be resorted to, a two stage system in which the liquefaction of the exhaust steam of turbine 5 is actually accomplished in a separate refrigeratively cooled condenser receiving partially cooled such steam, for instance from condenser 6 Fig. 1, preferably-being used and waste heat energy from the second condensing stage refrigerator perhaps with this system being utilized to (further) heat, through a suitably placed radiator, the compressed air fed into e.g. chamber 3 or expanding through nozzle 11.

Possibly the condensers 6 and 19 can be arranged to function as a two stage'unit, the exhaust steam from turbine 5 finally being condensed to a liquid state in either of said condensers or in a separate refrigerated (third) stage unit.

The low pressure steam exhausting from turbine 5 Fig. 1 is directed into entraining tube 2 and is compressed by compressor 1 and then utilized to heat boiler 4 in another version of the basic engine described, the said steam thereafter being expanded through nozzle 11 for example and passed into condenser 6 by an appropriate pipe connection. In a variation of this system of working, both exhaust steam and air is compressed in compressor 1 and used to heat boiler 4, the mixed steam and air efflux thereafter being expanded (through nozzle 11 and a connecting channel) into e.g. condenser 6 in which said steam is condensed and from which condenser said air is passed through a vent 22 into tube 2 and recycled. No vacuum would exist in condenser 6 and this is a disadvantage of this latter working method.

The condensers 6 and 19 normally require a vacuum pump not shown, to maintain their vacuum against air leakage into the compressor driving plant.

A powerful starter engine; such as an electric motor or the engine 17 Fig. 1, may drive the air compressor 1 when starting the main plant's working cycle, using for instance shaft 15 or gear-box 13.

Such a starter engine could also act as a reserve driving means for air compressor 1 in the event of the failure of said compressor's main driver; the coupling of said starter engine to said shaft 15 or gear-box best being through a freewheeling device allowing the rotation of said air compressor's rotor independently of said starter engine once, during the starting phase of the main plant, the steam turbine 5 is working. Electric heaters 23 help raise steam in boiler 4 during said starting phase.

Instead of the single assembly 3, 4, 11 Fig. 1, a plurality, such as a ring, of said units may be provided, perhaps feeding waste compressed air to a single auxiliary turbine power generator.

Fuel can be burned in the compressed air ejected through nozzle 11 Fig. 1 to increase the energy of this fluid.

The liquid fed to boiler 4 is a fuel, such as kerosene, in a particular arrangement, the exhaust steam (fuel vapour) from turbine 5 being diverted, when required, through a bypass into a combustor or a jet pipe also receiving the compressed air exhausted by nozzle 11 and burnt therein, e.g. to increase the thrust of a jet propulsion unit example. Such fuel could moreover be sprayed in its liquid form into said combustor or pipe and ignited and burnt therein.

The means for compressing the boiler heating fluid supplied to chamber 3 Fig. 1, in a further example, is a jet type compressor operated e.g. by compressed air derived from air compressor 1 or from a rotary vane or screw type air compressor or Roots blower similarly driven.

Although this invention is disclosed whereby the driving means of air compressor 1 Fig. 1 is a steam turbine, the use of any kind of steam engine as said means is contemplated. For example, a rotary vane steam engine or a gear-wheel motor (an adapted such pump) comprising a compound or multiple expansion steam engine and consisting of a series of two or more progressively larger capacity such motors having a single output shaft and through which series of motors the steam generated by boiler 4 would expand successively, could drive said air compressor 1.

A supply of liquid to reservoir 21 Fig. 1 is needed to compensate for any loss of said fluid by steam leakage from the air compressor driving main engine and the combustion of fuel exhaust steam.

The exit nozzle 11 may be adjustable to permit the construction or dilation of its orifice, e.g. to regulate produced thrust.

The thermal insulation of air compressor 1 Fig. 1, chamber 3 and all other assemblies likely to suffer an unwanted heat loss to the ambient atmosphere is necessary if the plant is to function at maximum efficiency and, to obtain a high primary air compression, said air compressor may comprise more than one rotor spool.

Because the air compressor driving means works, in the basic design, according to a condensing cycle, the operating range of an aircraft or other transportation apparatus installed with the power plant disclosed, would be virtually unlimited. Since the need to carry large quantities of liquid secondary fluid is thus avoided, the complete installation would also be substantially lighter than a design employing a non-condensing said air compressor driver. This is not to say however, that the compressor driver is unable to work as a non-condensing unit.

The freon substances seem to be useful secondary fluid liquids for steam generation in boiler 4 Fig. 1, but water or carbon-dioxide may be used for said purpose.

The usecf the air cooled condensers 6 and 19 or the like, does not preclude the practicability of the utilization of other condensing means, such as water cooled similar units, to condense the exhaust steam of turbine 5 Fig. 1.

Whereas in the concept providing for the use of the medium expanding through nozzle 11 for refrigeration or freezing purposes, the expansion of said fluid is necessary to obtain the low temperature required; where said medium is utilized in a heat-exchanger for heating purposes, it would be at high pressure and high temperature, the expansion and further use of the said fluid leaving a heatexchanger of said kind, for refrigeration or freezing, being practical.

In a final configuration, the steam exhausting from turbine 5 or an equivalent driver is utilized for purposes such as water or room heating, in a steam heated water boiler or heater, which may or may not also act as a condenser for said steam. In the former case, condenser 6 Fig. 1 for example, is omitted. In the latter case, condenser 6 for instance, is fed with the waste steam from said water boiler or heater.

Claims (26)

1. A jet propulsion unit or an adaptation thereof working at least primarily according to the thermodynamic cycle disclosed in my British patent specification GB 2086483B and comprising an axial flow rotary or rotary cum jet type primary heating fluid compressor, a connected chamber or chambers receiving primary fluid compressed by said compressor and containing or each containing a flash steam generator heated by said compressed primary fluid, a means fed with high pressure steam by said flash steam generator(s) for driving said compressor or its rotary part, an exit or exits releasing the spent compressed primary fluid directed through said chamber(s), and a condensing provision acting to liquefy the low pressure steam exhausting from said compressor or rotary part driving means, said pressurized steam being formed from a secondary liquid medium, usually condensate derived from said condensing provision, supplied to said steam generators(s).

2. A thermal plant as in Claim 1, optionally including an electric heater provision or provisions acting to further heat the compressed primary fluid directed through the steam generator cdntaining chamber(s), when starting said plant's working cycle, thus helping to raise steam in the steam generator(s).

3. A thermal plant as in Claim 1 or 2, including an exhaust steam condensing provision cooled by the working medium entrained by the primary fluid compressor, by the spent primary fluid expanded through the exit(s) of the steam generator containing chamber(s), by refrigerative means or by a combination of these methods.

4. A thermal plant as in Claim 1, 2 or 3, including steam generator containing chamber exit(s) arranged as a nozzle or nozzles or such nozzle(s) combined with jet or tail pipe(s) optionally incorporating the or an exhaust steam condensing provision.

5. A thermal plant as in any previous Claim, including an auxiliary mechanical power generator or a heat-exchange means fed with the spent primary fluid exiting from the steam generator containing chamber(s).

6. A thermal plant as in any previous Claim, including a steam generator secondary fluid feed pump or injector, an exhaust steam condenser vacuum-pump, a reservoir of the secondary liquid fluid fed to the steam generator(s) and a means for regulating the supply of said secondary liquid medium.

7. A thermal plant as in any previous Claim,including a means, such as an electric motor, for driving the primary fluid compressor or its rotary part during the working cycle starting period of said plant or upon the failure of said compressor's main driver.

8. A thermal plant as in any previous Claim, including a rotary cum jet type primary fluid compressor in which the motive fluid of its, said compressor's jet type portion is obtained from a rotary axial flow compressor or from a rotary vane, screw type or Roots such unit driven by means similar to those used to drive the purely mechanical such fluid compressor.

9. A thermal plant as in any previous Claim, including a primary fluid compressor or rotary part driver comprising a steam turbine, a rotary vane steam engine or a gear-wheel steam motor preferably having a plurality of expansion stages.

10. A thermal plant as in any previous Claim, including the use of the exhaust steam of the driver or main driver of the primary fluid compressor or its rotary part or a mixture of said steam and another gas medium, as said plant's primary fluid, the condenser vacuum pump being omitted in the latter working method.

11. A thermal plant as in any previous Claim, including a primary fluid compressor or rotary part thereof driven partially by the auxiliary mechanical power generator.

12. A thermal plant as in any previous Claim, including the use of the primary fluid compressor or rotary part driver or main driver or /and a power generator, which may be the auxiliary power generator driven by the spent steam generator heating high pressure primary fluid, for mechanical power production for remote utilization.

13. A thermal plant as in any previous Claim, including the use of the heat-exhange means or/and the exhaust steam of the primary fluid compressor or rotary part driver or main driver, to supply heat for remote utilization.

14. A thermal plant as in any previous Claim, including the use of the expanded spent primary fluid exited from the steam generator containing chamber(s) or leaving the heat-exchange means for refrigeration or freezing purposes.

15. A thermal plant as in any previous Claim, functioning at least principally as a jet propulsion unit and including a fan driven by the primary fluid compressor or rotary part driver or main driver, alternatively by the auxiliary mechanical power generator or both said driving means or by a separate engine, for displacing a further air volume for jet propulsion, this further air optionally also being utilized, by its direction over external cooling fins, to help cool the exhaust steam condenser otherwise cooled solely by the entrained air primary fluid.

16. A thermal plant as in Class 15, including a separate fan driver consisting of a two or four-stroke rotary vane engine working according to the thermodynamic cycle defined in my patent specification GB 2086483B.

17. A thermal plant, for example an air breathing jet propulsion unit or an engine incorporating an auxiliary turbo-power generator, as in any previous Claim, including a provision to burn fuel, when required, in the spent compressed air primary fluid leaving the steam generator containing chamber(s) to increase the total energy of said compressed air, said fuel optionally being the exhaust steam of the primary fluid (air) compressor or rotary part driver or main driver, said fuel combustion being effected in a combustion chamber provided or in an embodied tail or jet pipe system fed with said fuel and compressed air media.

18. A thermal plant as in any previous Claim, including a provision to liquefy the exhaust steam of the primary fluid compressor or rotary part driver or main driver in a water cooled condenser.

19. A thermal plant as in any Claim 1 to 17, including a primary fluid compressor or rotary part driver or main driver exhaust steam condensing provision having one or a plurality of working stages.

20. A thermal plant as in Class 19, including the utilization of the spent compressed primary fluid in a mechanical power generator or the heat-exchange means or for jet propulsion purposes subsequent to its direction through a nozzle and tail or jet pipe exit assembly incorporating the or a condensing provision fed with the or a portion of the exhaust steam of the primary fluid compressor or rotary part driver or main driver.

21. A thermal plant as in any previous Claim, including a single or multiple steam generator, containing chamber and spent compressed primary fluid exit assembly.

22. A thermal plant adaptation as in any previous Claim, arranged to function partly or exclusively to generate mechanical power, as a heat generator, as a cold gas producer, or as a gas compressor, pump ejector or liquefier.

23. A thermal plant as in any previous Claim, including a connection of the primary fluid compressor or rotary part driver or main driver power output shaft to a gearbox through which ancillary equipment is driven thereby and the starter engine may drive said compressor or its rotary part, optionally via a freewheeling device allowing said compressor or rotary part to rotate after said plant's starting period, independently of its drive by said starting engine which otherwise is connected directly to said power output shaft or thereto through said freewheeling device.

24. A thermal plant as in any previous Claim, including a provision to recover waste heat generated by the refrigerator or a refrigeratively cooled exhaust steam condenser by utilizing said waste heat to increase the temperature of the compressed primary fluid, either before or after its utilization to heat the steam generator.

25. A thermal plant as in any previous Claim, including a provision to continuously recycle either or both primary and secondary working fluid, where said primary fluid is mixed secondary fluid steam and another gas, the spend said mixture being directed into the condensing provision, from which, after the condensation of said spent mixture's steam content, the remaining gas finally vents into the primary fluid compressor's entraining tube, said condensing provision being of any chosen design, said entraining tube optionally embodying external circumferential heat conducting fins enhancing the condensation of exhaust steam by a jacket condenser encircling it and receiving said steam or spent mixture, ducted fan jet propulsion units having said fluid recycling provision, as in a condensing fully closed system turbo-fan such unit for example recycling both its primary and its secondary fluids separately or as said mixture, since no primary fluid may be ejected to exert a thrust reaction, said units possibly developing a propulsive thrust only by the air displacing action of their fans, thermal plants so arranged forming fully or partially closed system engines optionally employing an inert gas primary fluid in the former instance.

26. A jet propulsion unit or an adaptation thereof designed, constructed or operating substantially as hereinbefore described with reference to Figs. 1 and 2 of the accompanying drawings.