Patent GB-1029840-A (GB)
Title: Improvements in thermal engins, for example gas turbine engines, jet propulsion units and engins powered by nuclear reactors
IPC: F02K7/12
Filed: 1961-10-25
Abstract: 1,029,840. Gas turbine and jet propulsion engines. H. A. KERSHAW. Aug. 9, 1962 [Oct. 25, 1961], No. 38150/61. Headings FIG and F1J. [Also in Division G6] In a thermal engine capable of operation when stationary or in motion, a jet type air compressor 1, Fig. 1, comprises a jet nozzle 2 which ejects combustion gases, fed through a conduit 6 from the combustion chamber 4, to entrain therewith air entering the compressor at 8. The resulting mixture passes into the chamber 4 to supply air for combustion of fuel, such as oil, supplied to a burner 10. A throttle valve 9, such as a butterfly valve, controls the flow of gas through the conduit 6 and thereby the supply of air for combustion. The valve 9 may be completely closed and the air compressed by ram effect. A cylinder 11 contains compressed air which is fed through a control valve 13 to a nozzle 14 for starting purposes; a compressor 16 driven by an air driven screw 15 replenishes the cylinder 11 during normal operation of the engine. The screw 15 may also drive ancillary equipment such as fuel pumps, ignition dynamos and the like. Alternative starting systems may comprise an electric motor driven rotary or piston type air compressor or a cartridge type gas generator. The chamber 4 is provided with cooling fins, two of which are shown at 4a and 4b. A jet ejector pump (not shown) driven by the jet efflux exhausting through the propulsion jet nozzle 5 may induce a flow of cooling air through a cowling arranged to direct this air over the combustion chamber cooling fins. The cooling may be obtained by a power driven fan or by the use of excess combustion air or a cooling jacket either exclusively or in combination with the method shown in Fig. 1 or that shown in Fig. 3 (not shown) in which the finned combustion chamber and part of the compressor are enclosed in a tubular chamber which is open at the combustion chamber end to allow air to be drawn over the combustion chamber and pass into the compressor through an additional port in the side of the compressor. In the embodiment of Fig. 3 the combustion gases are fed to a gas turbine and the jet compressor may be a multi stage unit powered partly by the exhaust gas of one or several stages of the gas turbine, the final stage of the compressor being powered by the combustion. In another embodiment, Fig. 2, a gas cooled nuclear reactor 24 for continuous thermo-nuclear reaction comprises a pressure chamber 25 containing a core of radio-active fuel such as uranium metal elements and a graphite moderator. Gas, such as carbon dioxide, is passed continuously by a jet compressor 26 into the chamber 25 where the temperature of the gas is increased and from where some of the gas is passed to the jet nozzle 34 for ejection, and the remainder is passed to a heat exchanger 20 for heating air supplied to a chamber 19 by a jet nozzle 23 supplied with some of the heated air through a conduit 22. The gas may pass from the heat exchanger 20 to a valve 29 either through a conduit 32 or a second heat exchanger 28, which preheats the entrained air. The valve 29 may restrict the gas flow to a diffuser 29a where it is expanded, thereby controlling the pressure of the gas and thus the mean temperature in the heat exchangers. The valve 29 may be replaced by a constricted orifice or by a small diameter delivery tube. Compressed carbon dioxide may be used as the motive fluid for starting the reactor 24, this gas being recoverable for re-use by an auxiliary compressor driven by an airscrew as previously mentioned.