GB2200409A - Fluid jet device - Google Patents

Abstract

A device for producing a jet of fluid comprises a manifold 1 (Fig. 1) for conveying air, compressed by a main, jet-type, compressor (not shown), to a heat exchanger 2 from which the heated compressed air passes to a jet pipe 5 having thrust vectoring exits 15 (Figure 2). The heat for the heat exchanger 2 is provided by the compression of air supplied by pipe 8 and which has been used previously to cool the main compressor. The cooling air is compressed by a jet pump 3 driven by main working fluid extracted via line 7. Cooling fluid exits the heat exchanger via line 12 and is returned to the main compressor. By-pass cooling fluid may be conveyed by line 13 and valve 14 into the airstream entering the main compressor. The main compressor is driven by working fluid extracted via line 10. Baffles 11 guide the compressed cooling air through the heat exchanger 2 over pipes through which the main working fluid flows. Compressor 3 can be replaced by a mechanical compressor (e.g. centrifugal) driven electrically, by an engine or by a turbine driven by air entrained by the main compressor. The use of gas turbines, gas generators, alternative forms or heat exchanger, and thrust reversal means are referred to. Jet pipe 5 may exhaust into a chamber 17 (Figure 3) and "vacuum chamber" 18 having a jacket 19 into which cooled air expands via vents 20 before being conveyed by pipe 21 back to the main air compressor. <IMAGE>

Description

IMPROVEMENTS IN THERMAL ENGINES AND RELATED APPARATUS Thermal engines basically similar to those to be described employ a reactor to heat their working fluid, the heating medium of said fluid afterwards being utilized to cool the compression means of the working fluid before recycling through said reactor. The reactor may be an atomic unit or a plant of some other kind.

In a modification of such thermal engines the reactor functions to heat the working fluid only by the compression of its own working medium, no additional heat generated by atomic reaction or other means being applied to said fluid.

My invention is primarily for a thermal engine of the latter kind and in which the compression of the working medium, which is a gas or air, of the reactor is effected by specific means. A method of obtaining a lifting thrust reaction in a jet propulsion unit embodiment is also described.

The invention concerns a modification of the thermal engines disclosed in my United Kingdom patent specification No. 1318282.

In accord with the invention, a thermal engine, for example a jet propulsion unit a gas turbine engine or a gas generator unit including reactor means functioning to convey heat from its working fluid under compression back to said working fluid during its expansion, characterized by the fact that the working medium of said reactor means is itself compressed by a mechanical or a non-mechanical fluid compression provision, viz of novel sort.

According to a feature of this invention, the reactor working medium compression provision is a centrifugal turbo-compressor variously driven According to a second feature of this invention, the reactor working medium compression provision is a jet type compressor powered by a portion of the engine's working fluid.

According to a third feature of this invention, the reactor working medium compression provision is a gas generator unit of various possible design.

According to a fourth feature of this invention, in a jet propulsion unit configuration the engine's working fluid is exhausted, when required, through an adapted thrust reversal means producing a lifting thrust.

The invention may be applied to a variety of kinds of jet propulsion units inclusive of lift-thrust engines, turbo-fan engines and the like, and togas turbine engines and gas generator units.

The object of the invention is to provide a reactor means most suitable for use with the thermal engines defined.

Some actual embodiments will now be described with particular reference to the accompanying drawings, in which Fig. 1 is a diagrammatic axial part-section of a portion of a reactor powered jet propulsion unit according to the invention.

Fig. 2 is a diagrammatic cross-section taken on line AA of Fig. 1.

Fig. 3 is a diagrammatic general arrangement of a modification of the jet propulsion unit shown in Figs. 1 and 2, but drawn to a smaller scale.

Referring to Figs. 1 and 2, in the first example, air compressed by the unit's jet air compressor (not shown in the drawings), i.e. said unit's main such device, is directed through a manifold 1 into the hot tubes of a multitubular heat-exchanger 2 which, in combination with another jet air compressor 3 and the air cooling system of the air compressor first mentioned, comprises the unit's reactor. The compressed air passed into the tubes of heat-exchanger 2 is heated therein and then conveyed from their outlets, or mostly so, by a second manifold 4 into å jet pipe 5 from the open rear end of which said heated compressed air is normally ejected to exert a forward thrust reaction.

The tubes of the heat-exchanger 2 are themselves heated externally by compressed air delivered to the outer chamber of said heat-exchanger by air compressor 3, which is powered by some of the heated compressed air leaving said tubes and fed to its power nozzle by a scoop 6 positioned in manifold 4 and a pipe 7 and also receives the low pressure used cooling air exhausting from the cooling system of the unit's main air compressor through a pipe 8, the latter air compressor being powered by a further portion of the heated compressed air from said tubes directed to it by a second scoop 9 placed in said manifold, and a connected conduit 10.

The air compressor 3 acts to compress the low pressure used cooling air supplied to it by pipe 8 and pass said compressed fluid, which is the heating medium of the tubes of heat-exchanger 2, into the one end of this last device's outer chamber. The compressed air, which is at a high temperature, is guided by three baffles 11 alternately upwards and downwards over said tubes, giving up most of its heat to them, and, except for a portion of this spent air which is bypassed, for example to atmosphere, finally leaves the other end of said outer chamber through a pipe 12 and is expanded back in a cold state into the cooling system, which may consist of both stage and interstage coolers, of the main air compressor.

The compressed air volume bypassed from heat-exchanger 2, in the present instance is led from the outlet end of said assembly's outer chamber through a pipe 13 having a regulating valve 14 into the air stream entering the unit's main air compressor and recycled, but said air might first be utilized to drive an auxiliary power generator, such as an air turbine. This air bypassing is essential because air compressor 3 is operated by fluid, which increases the quantity of working medium circulating in the reactor, from manifold 4. Instead of jet air compressor 3, a mechanical unit, for example a centrifugal air compressor electrically or auxiliary engine driven, may compress the reactor's working medium, in which case said air bypassing is unnecessary.

Alternatively, a mechanical air compression means replacing the jet unit 3 can be driven by an air turbine placed in the air entraining system of the main air compressor and rotated by the air entrained by said air compressor, through a countershaft and gears (gear-wheels), or in embodiments incorporating a gas turbine fed with the heated compressed air leaving manifold 4, by such a turbine. Another arrangement consists of a gas turbine (which may be an auxiliary such unit) driven centrifugal air compressor operated by a heated compressed air quantity diverted from manifold 4 to it through, for example, scoop 6 and pipe 7.However a gas generator unit of any suitable design, such as a said unit in accord with this invention, may optionally compress the reactor's working medium, which may be super-heated e.g. by electrical or combustion gas heating means, immediately before or after its compression.

An example in which the reactor has a separate reaction chamber could include a heating provision in said chamber, the heat-exchanger 2 in this case receiving hot compressed air from said reaction chamber, for heating its tubes.

A heat-exchanger of a different kind can be used in lieu of the assembly 2, which consists of a cylindrical outer tube/chamber through which multiple smaller diameter tubes pass longitudinally, for example a coiled tube unit.

A plurality of heat-exchangers is provided in place of the single assembly 2, either with individual air compressors or all supplied with compressed air by the air compressor 3 or such a device replacing it, in a further construction.

If desired, the jet pipe 5 may embody a conventional thrust reversal means of the kind in common use with existing turbo-jet and turbo-fan engines.

In such a means the heated compressed air ejected through pipe 5 would, when said means is in operational use, be bypassed through an aperture or apertures exposed by the eyelid(s) of a valve then reciprocally obstructing the normal exit of said pipe, and located at e.g. said pipe's one or both sides, and deflected by curved vanes in a forward direction.

In the embodiment illustrated an arrangement identical to a thrust reversal means of said kind, except that curved vanes 15 disposed longitudinally across a single aperture 16 provided in the near-side of jet pipe 5 deflect the heated compressed air, when required to exert a lifting thrust, downwards, is incorporated, but both sides of said jet pipe may, where necessary, be equipped with such an aperture and vane provision through which said air would be bypassed for said purpose.

The method whereby the air feeding the reactor is compressed by jet compressor 3 Fig. 1 has the advantage of simplicity and in the respect that starting the main air compressor would automatically start said reactor air compressor thus avoiding the need for a separate starting means for this device.

The use of a gas generator unit of a particular kind (a hot tube or chamber unit) as the reactor's working medium compressor is disclosed in my aforesaid U.K. patent specification. With my present invention nevertheless, novel such units in accord with said present invention or as disclosed in my U.K. patent specification No. 946,443 may compress the reactor's working medium feeding heat-exchanger 2 or an associated separate reaction chamber.

A further modification has a working medium heating or/and superheating provision in its separate reaction chamber assembly or in heat-exchanger 2 and employs a turbo-air compressor in which its driving turbine is interposed in pipeline 12 and driven by the compressed air expanding through said pipe into the cooling system of the main air compressor of the engine, to compress the air feeding said separate chamber or said heat-exchanger.

Conversely, the jet air compressor 3 is powered by some of said compressed air, but the method described with reference to Fig. 1 is the preferred manner of operating said air compressor 3.

Referring also to Fig. 3, under for instance space flight conditions, it would greatly increase the practical range of operation of a vehicle equipped with the engine if it was possible to recover and recycle the compressed hot air ejected (and expanded) through jet pipe 5. In said figure this is effected in a cylindrical chamber 17 into which pipe 5 exhausts its air through a connecting vacuum chamber 18 and in which said air is partially recompressed by the conversion of its momentum into fluid pressure and cooled by a jacket 19 into one end of which said cooled air finally expands through vents 20 provided in the downstream end of said chamber. The low pressure air, which isthe medium cooling chamber 17, leaves jacket 19 via a pipe 21 connected to its, said jacket's forward end and thereafter is recycled through the main air compressor of the engine.

The chamber 17 has a convergent/divergent inlet and, in a refined form, is equipped with external cooling fins circumferentially or longitudinally disposed to assist its cooling by jacket 19. With this arrangement, some of the total thrust produced by the ejection of compressed air through pipe 5 is unavoidably lost due to the counterthrust exerted by the partly recompressed air on the rear end of chamber 17, in the reverse direction.

This counterthrust is reduced by cooling the air exhausting into chamber 17, thus lowering the pressure of said air, the overall thrust reaction being forwards.

A multitubular or coiled tube heat-exchanger cools or supplements the cooling of the air recompressed in chamber 17 Fig. 3 in a variation of the working fluid recovery and recycling system described, such a heat-exchanger utilizing cooled air from said chamber as its coolant in a similar manner to that of jacket 19 and being incorporated in chamber 17, which may or may not embody vents 20 and said jacket, as is appropriate, in this case.

A gas generator unit embodiment including a heat-exchanger fed with the heated compressed air or gas produced by said unit and functioning partly or exclusively as a heat generator is practicable, as also is an air compressor adaptation of the jet propulsion unit described with reference to Fig. 1, and combined such designs.

Closed circuit engines can at least partly effect their (main) air or gas compression by ram action due to the momentum of the recycled said fluid, which may in all such plants be any desired or convenient medium.

In practice, the reactor compressor may be operated, in examples featuring additional heating of the reactor working medium, by such (compressed) fluid obtained from any convenient point in the reactor circuit.

The scoops 6 and 9 in gas turbine driving examples might alternatively be positioned downstream of their gas turbines, rather than as is shown in Fig. 1.

The outer chamber of heat-exchanger 2 Fig. 1 forms the reaction chamber of the reactor of the first example.

In examples having a closed main working fluid system, the use of an inert such fluid, for example carbon-dioxide, freon or nitrogen gases, may be preferable to obviate any possibility of an explosive reaction occurrence in their said systems.

To permit control of the action of the main air (or gas) compressors and that of e.g. reactor compressor 3 Fig. 1, of examples and the thrust or power developed by embodiments, all pipes and channels, such as pipes 7 and 8 and conduit 10 Fig. 1, carrying low or high pressure working fluid to said compressors or their driving means may be fitted with regulating valves preferably operated automatically by a governor or governors with a manual override.

A final embodiment includes a gas generator unit according to U.K. patent specification No. 1100903, except that power (motive) fluid to effect said mit's own air compression is obtained from any of the sources described for supplying such fluid to air compressor 3 Fig. 1 in the present specification, as the reactor air or gas compression means.

Either single or multiple or/and single or multistage reactor working medium compressors are employable.

Claims (12)

1. A reactor powered thermal engine, for example a jet propulsion unit. a gas turbine engine or a gas generator unit, including a reactor means primarily of a non-atomic kind and functioning to heat said engine's main working fluid exclusively by the compression of a gas or air working medium acting previously as the coolant of its, said engine's, main working fluid compressor provision, which is a jet type such device operated by a portion of said heated main working fluid and possibly embodies a main working fluid recycling capability. and the utilization of said compressed gas or air in a heat-exchange system for said purpose, said reactor working medium compression being effected, for instance, either by a centrifugal turbo-compressor or a single jet type compressor or by a gas generator unit.

2. A thermal engine as defined in Claim 1, including a centrifugal turbo-compressor driven electrically or by an auxiliary engine or an auxiliary or main gas turbine means, for compressing the reactor working medium, said auxiliary gas turbine provision being operated by either the entrained low pressure main working fluid or a portion of the heated and compressed such fluid or, in examples featuring the heating or/and superheating of the reactor working medium, by the spent high pressure said reactor medium exiting from the heat-exchange system, said heating or/and superheating of the reactor working medium being additional to the heating of said medium in the cooling means of the main working fluid compressor provision and by its own compression, said centrifugal turbo-compressor being of a single or multi-stage design and, in the appropriate instance, being driven by some of the heated main working fluid through an auxiliary gas turbine arrangement fed with said main fluid by a scoop device placed in said main fluid stream and connected by a conduit to said gas turbine assembly, or by any other chosen means.

3. A thermal engine as defined in Claim 1, including a single or multi-stage jet type compressor means operated by a portion or portions of said engine's heated compressed main working fluid stream(s) derived from a scoop device means placed therein or, in examples featuring the additional heating or/and superheating of the reactor working medium, by a portion or portions of the spent high pressure said reactor medium exiting from the heat-exchange system, for compressing the reactor working medium, in a gas turbine engine example, said scoop device means being located either before or behind the gas turbine or main such machinery.

4. A thermal engine as defined in Claim 1, including a gas generator unit means in accord with my British patent specification number 946443 or, except in that its jet compressor provision is powered by some of said engine's high pressure main working fluid or, in examples featuring the additional heating of the reactor working medium, by a portion of the high pressure spent latter medium leaving the heatexchange system, in accord with my British patent specification number 1100903, for compressing the reactor working medium.

5. A jet propulsion unit as defined in any preceding Claim or Claims adapted to function or partly function as a gas, for example air, compressor plant.

6. A gas generator unit thermal engine as defined in any preceding Claim or Claims 1 to 4, adapted to function or partly function as a heat producing plant utilizing the heated and compressed main working fluid and heat-exchange means fed therewith, for said purpose.

7. A thermal engine adaptation as more particularly defined in either of the preceding Claims 5 and 6, arranged to function both as a gas compressor plant and as a heat generator.

8. A thermal engine, namely a jet propulsion unit, as defined in any of the preceding Claims 1 to 4, including, in its jet pipe, a thrust reversal facility or an adaptation thereof modified simply by the longitudinal disposal or placing of its gas deflectors and producing, when required, a lifting thrust reaction by directing the propulsion jet efflux normally exiting rearwards, downwards from apertures provided in one or both sides of said jet pipe.

9. A thermal engine, namely a jet propulsion unit as defined in any of the preceding Claims 1 to 4, modified to exert a reactive thrust whilst continuously recovering and re-cycling its main working fluid, said main fluid recovery being in a re-compression and cooling chamber means accepting expanded said fluid exhausting via a vacuum chamber thereinto through said engine's jet pipe, said re-compression chamber cooling being effected by either or both jacket and coiled tube or multi-tubular heat-exchanger means embodied in said re-compression chamber means and into which cooling device(s) partially re-compressed said main working fluid thereafter expands and acts as the coolant of said re-compression chamber provision which optionally incorporates external fins enhancing its cooling by said jacket, and its compressed fluid, which is only partially re-compressed therein, i.e. by the convers'oii of the momentum of the entering working fluid jet into pressure, and is wholly expanded through vents into said cooling device(s) before re-cycling through the engine, which develops an overall forward thrust due to the expulsion of said fluid jet and a reduced fluid pressure achieved in said re-compression chamber means by the cooling thereof.

10. A thermal engine as defined in any of the preceding Claims.

alternatively employing a thermodynamic working cycle including the application of additional heat to the reactor means' working medium, either in the form of heating of said medium in the reaction chamber(s) of said means or up-stream thereof or the later superheating of said reactor working medium or both said kinds of heat application.

11. A thermal engine as defined in any of the preceding Claims, including a reactor heat-exchange system consisting of one or more heat-exchanger devices, said device(s), where of multitubular design, incorporating internal baffles directing hot compressed reactor working medium repeatedly over the tubes thereof, where a jet type reactor working medium compressor means using a portion of said engine's main working fluid as its motive fluid is embodied, said device or devices having a bypass provision or provisions releasing high pressure excess spent said reactor medium therefrom, and optionally through an auxiliary power generator, to atmosphere or re-cycling with said main working fluid, said heat-exchange device(s), as appropriate, receiving compressed hot said reactor working medium from a gas generator unit means, which may be auxiliary in nature, of any preferred or alternative design, for example a such means in accord with the present invention, said heat-exchange system, where of a multiple unit configuration, receiving main working fluid under pressure from separate jet compressors or a common such fluid jet compressor means, said main and reactor working media being any required gas fluid or fluids, inclusive of air and inert gas such media.

12. A reactor powered thermal engine working according to a continuous cycle, designed, constructed and operating, i.e. substantially as hereinbefore described with reference to the accompanying drawings, including one or a plurality of reactor working medium compressors, a gas generator unit said reactor medium compressor or/and any of the modifications disclosed in said description, the "forward thrust" produced by the embodiment defined in preceding Claim 9, being exertable in any direction, depending on the said engine's attitude, and the action of all examples being controllable by the adjustment of valves provided, regulating the movement of fluid through the various supply and exit channels.