Patent GB-676008-A (GB)
Title: Improvements in or relating to gas turbine plants
IPC: F01K21/04
Filed: 1949-02-24
Abstract: 676,008. Gas turbine plant, axial flow compressors. SOC. RATEAU, and ANXIONNAZ, R. Feb. 24, 1949 [Oct. 11, 1948; Dec. 10, 1948], Nos. 5109/49 and 5110/49. [A Specification was laid open to inspection under Sect. 91 of the Acts, Aug. 29, 1949.] Classes 110(i) and 110(iii) [Also in Group XII] In a gas turbine plant, in which water is added to the compressed air and is vaporized by the heat of compression in one or more evaporator saturators at least one of the evaporator saturators located after a compressor is provided with means for removing water from its base, and conveying it without heat exchange with the air within the compressor to heating means heated by the turbine exhaust gases and returning it to the evaporator saturator so that it flows from top to bottom in contact with the air delivered by the compressor. The heat extracted from the turbine exhaust for heating the injection water to the evaporator saturators may be controlled by thermostats to prevent condensation of steam in the turbine exhaust. Fig. 2 shows a plant with inter-stage evaporator saturators h 1 , h 2 , h 3 . These may be supplied with unheated water or the water may be heated in exchangers a 3 , a 2 , a 1 . In the former case, a further saturator may be located after the last compressor stage b\ and be supplied with water heated in an exhaust gas heat-exchanger after the preheater a. Thermostats w control valves u in lines which byepass the exchangers so that the exhaust gas temperature shall not fall to the dew point. Water from the evaporated saturator drains s gives up heat in exchanger q to the fresh water from pump n. In Fig. 3 fluid in a closed circuit is heated in an exchanger a 1  and gives up heat in exchangers p 1 , p 2 , P 3  to the injection water for the evaporator saturators h 1 , h 2 , h 3 . The heat taken up in exchangers p 1 , p 2 , is regulated by byepass valves u controlled by thermostats v responsive to the difference between the temperatures of the heated water and the air leaving the evaporator saturator. The heat taken up in exchanger p 3  is regulated by a valve u controlled by a thermostat w responsive to the temperature of the fluid returning to the exchanger a,. The evaporator saturators h 1 , h 2 , h 3 , Fig. 2, comprise an inlet manifold J, feeding a number of tubes J having a cylindrical or other cross-section open at their upper ends but covered by stationary caps k which compel the water to trickle from top to bottom outside the tubes. A separating screen may be set above the tubes to prevent carry over of water particles into the following compressor. In other forms of evaporator saturator described the water is passed directly into the air through atomizing nozzles or trickles on to vertical or sloped plates. In Fig. 5, water is heated in an inter-stage cooler s and in an exhaust heat -exchanger a<SP>1</SP> and is injected into a saturator h located after the compressor delivery. An additional interstage cooler s 1  may be provided In the plant shown in Fig. 6 an inter-cooler l between compressor stages b 1 , b 2  heats the injection water for a saturator h 1  between stages b 2 , b 3  and the water for a saturator h 2  between stages b 3 , b 4  is heated in an exchanger a 1 . Turbine-compressor arrangements.-In Figs. 2 and 3, turbines f 1 , f 2  which drive a generator g are in parallel with turbines f 3 , f 4 . L.P. turbine f 3  drives the H.P. compressor stages b 3 , b 4  and H.P. turbine f 4  drives the L.P. stages b', b<SP>2</SP>. In Fig. 5, the the first and second turbine stages f, drive compressor stages b 1 , b 2  and the last turbine stage f 2  drives a generator g. The turbine stages f, may be in parallel, both exhausting to stage f 2 . In Fig. 6, turbine stages f 1 , f 4  axe in parallel with stages f 2 , f 3  and both pairs exhaust to turbine f  5 . The first and second compressor stages b, b 2  are. driven by the intermediate turbine stages f 3 , f 4 . The third and fourth compressor stages are driven by the H.P. turbine stages f 1 , f 2 . In all the plants, reheating is provided before all following turbine stages. In the plant shown in Fig. 2, starting motors C, C' are provided for the two compressor-turbine sets b 1 , b 2 , f 4  and b 3 , b 4 , f 3 . As in Fig. 3, the motor C<SP>1</SP> may be omitted. The Specification as open to inspection under Sect. 91 of the Acts comprises also a number of modifications of the plants described above. In one of these the feed water to the evaporator saturators is not heated by the turbine exhaust gases whilst in another, the feed water is additionally heated by the compressed air between two of the compressors. A further modification describes a jet propulsion engine in which water is injected between the stages of an axial flow compressor. This subject-matter does not appear in the Specification as accepted.