GB690739A - Improvements in or relating to power generating plants - Google Patents

Abstract

690,739. Semi-rotary pumps and engines; gas turbine plant. ABBEY, A. (Soc. De Constructions Mecano-Thermiques). Nov. 2, 1949, No. 28111/49. Classes 110(ii) and 110(iii) [Also in Group XXVII] In a power plant comprising a main useful power prime mover and an auxiliary prime mover, the auxiliary prime mover is fed with high-pressure gases in. which fuel is burnt and the main prime mover with medium-pressure gases formed partly by the exhaust gases of the auxiliary prime mover and partly by compressed air in which fuel is burnt. The auxiliary prime mover drives a compressor supplying air to both of the prime movers. In the arrangement shown, Fig. 1, an internal combustion engine 2 drives an air compressor 3 delivering high pressure compressed air to a combustion chamber 7. Another air compressor 9 driven by an auxiliary prime mover 11 also supplies air to the combustion chamber 7. The combustion gases from the chamber 7 are expanded in the prime mover 11, then reheated in a combustion chamber 17 and expanded in the useful power turbine 21. The combustion chamber 17 is also supplied with combustion air at the required pressure by the compressor 9. Another arrangement, Fig. 3, comprises a prime mover compressor unit 23 which consists of a low pressure compressor 25, a high pressure compressor 55, an auxiliary prime mover 63 and an internal combustion engine 101, all of which are of the free piston oscillating vane type. The compressor 25 consists of eight chambers, two of which 37, Fig. 4, are used to compress air for supercharging the internal combustion engine 101, another two of which 39 are used for the initial compression of the air supplied to the medium pressure combustion chamber 85 and the remaining four 45 are used for the initial compression of the air supplied to the high pressure combustion chamber 69. The high pressure compressor 55 also has eight chambers which are divided into two sets of four and used for the final compression of the air supplied to the combustion chambers 69, 85. The air may be cooled during compression by injecting atomised water into the compression chambers and intercoolers may be provided between the two compressors. The high pressure air from the compressor 55 passes through the cooling jacket of the auxiliary prime mover 63 and jackets 65, 68 surrounding the hot gas supply pipe 67 and combustion chamber 69 to a heat exchanger 73 where it is further heated by the exhaust gases from the internal combustion engine 101. Fuel is burnt in this air in the combustion chamber 69 the gases from which drive the auxiliary prime mover 63. The exhaust gases from this prime mover pass through a pipe 81 into the combustion chamber 85 which is also supplied with combustion air from the compressor 55 through a pipe 89. This combustion air is preheated in jackets 86, 92 surrounding the pipe 93 leading from the combustion chamber 85 to the turbine 95 and the combustion chamber 85. The exhaust gases from the internal combustion engine after leaving the heat exchanger 73 pass into a low pressure stage of this turbine. In a modification, the combustion chamber 69, 85 are surrounded by jackets. The jacket surrounding the chamber 69 is used to generate steam for use in a steam turbine connected to the shaft of the gas turbine 95. The jacket surrounding the chamber 85 is used to reheat the steam passing through this turbine. The condensate leaving the condenser of the steam turbine may be heated in bled steam feed water heaters before passing to the jacket surrounding the chamber 69. Part of this condensate may be extracted from between the heaters and used to cool the internal combustion engine and the pipe leading to the heat exchanger 73. The steam resulting from this arrangement is used in a low pressure stage of the steam turbine. Preferably, the steam pressure in the jackets of the chambers 69, 85 are the same as the gas pressures in the chambers. Modifications in which the air supplied to the chamber 85 is preheated by the exhaust of the internal combustion engine, in which the air supplied to the chamber 69 is heated in the cooling jacket of this engine and in which the air and water are preheated by the exhaust gases of the turbine 95, are also described.