Patent GB-668068-A (GB)
Title: Combined gas and steam power plants
IPC: F01K23/10
Filed: 1948-06-15
Abstract: 668,068. Gas turbine plant. AKTIEBOLAGET DE LAVALS ANGTURBIN. June 15, 1948. [July 1, 1947; Jan. 20, 1948; Feb. 26, 1948] Nos. 16058/48, 16059/48 and 16060/48. Class 110(iii). In a combined gas and steam power plant comprising a gas power section containing at least one compressor and a combustion chamber feeding a rotary gas power engine of the continuous flow type and a steam power section containing a boiler unit comprising boiler and economizer supplying steam to a turbine, a condenser and a feed pump, the exhaust gases from the last power engine reckoned in the direction of flow of the motive fluid are supplied direct to the boiler unit and are subsequently led, within the boiler unit, into contact with a regenerator for the gas power section. In the plant shown, Fig. 1, a compressor 10 supplies air through a regenerator 32 located in a boiler unit 18 to a combustion chamber 14, the combustion products from which pass to a turbine 12 driving the compressor. The exhaust gases from the turbine 12 pass through ducts 16 to the boiler unit 18 which supplies steam to the turbine 22. The turbine exhaust steam is condensed in a condenser 24 and then pumped back to the boiler. The gas and steam turbines 12, 22 are coupled to the opposite ends of an electric generator 30. To obtain additional heat for peak loads, a fuel oil burner 28 is provided. A two-way valve 34 is provided to enable the regenerator to be byepassed so as to increase the heat available for steam generation at higher loads. In a modification, a second gas turbine and associated combustion chamber is arranged in parallel with the gas turbine 12 after the regenerator 32. This turbine drives the output shaft through gearing in association with the steam turbine and the turbine 12 is used solely for driving the compressor 10. The steam turbine 22 may also be divided into two parts one part forming an ahead turbine and the other an astern turbine. When the astern turbine is in operation the second gas turbine is rendered inoperative by closing a valve in the compressed air supply to its combustion chamber. In a further modification, Fig. 3, two gas turbines 12, 36 arranged in series with a reheating combustion chamber 38 between them are used. The high pressure turbine 12 is used to drive the two-stage compressor 10 and the low pressure turbine 36 is coupled to the output shaft. In this arrangement the regenerator 32 is placed between two sections of the economizer 62. The position of this regenerator is stated to be that at which the temperature difference between the feed water and the flue gases is maintained substantially constant. In a further modification the tubes of the regenerator are intercalated with the economizer tubes. A further heat exchanger 68, 70 may be used for generating low temperature steam or for producing warm water. It is also stated that the steam turbine may be of the double rotation type disposed between two co-axial electric generators and direct-coupled to the inner shaft ends of said generators, each of the outer shaft ends of said generators being directcoupled to a gas turbine. Specification 630,000 is referred to. The Specification as open to inspection under Sect. 91 comprises also combined steam and gas turbine power plants in which the regenerator 32 is omitted and in which the compressor and its driving turbine are coupled through gearing to the output shaft. A further arrangement in which the compressor is not coupled direct to the turbine but is driven from the gearing connecting the steam and gas turbines is also described. In both of the latter arrangements, a valve is provided between the compressor and gas power plant combustion chamber so that when the reverse steam turbine is in operation, compressed air is diverted from the combustion chamber of the gas power plant to the boiler where it is used as combustion air for the boiler 28. This subject-matter does not appear in the Specification as accepted.