GB836135A - Improvements in and relating to gas turbine plant - Google Patents

Abstract

836,135. Gas turbine plant. POWER JETS (RESEARCH & DEVELOPMENT) Ltd. Jan. 16, 1958 [Jan. 18, 1957], No. 1971/57. Class 110(3). A gas turbine plant in which a compressor driven by a turbine supplies combustion air to the primary zone of a combustion chamber comprises a heat-exchanger arranged to heat air before entering the combustion chamber, a duct by-passing the heat-exchanger to connect the turbine exhaust directly with atmosphere and a duct connected to pass air directly from the compressor to the second entry which is so located that this air forms a cooling air stream and at least a part of the secondary combustion air. A compressor 1 discharges through a heatexchanger 2 to a first entry of a combustionchamber 3 feeding a turbine 4 driving the compressor. Primary combustion air enters through the first entry. Air from the compressor 1 also passes through a duct 7 to an annular channel 8 connected by ports in the combustion chamber wall to the space between the outer casing 9 and flame tube 11. These ports constitute the second entry to the combustion chamber. A flow control valve 10 is located in the duet 7. The turbine exhausts through the heatexchanger 2. A heat-exchanger by-pass duct 17 and valve 18 are also provided. The valve 10 may be operated either manually or automatically and preferably in dependence upon the pressure drop across the heat-exchanger. The valve 10 is progressively opened as the load is increased. The flow control valve 18 may be adjusted either manually or automatically. In a modification, Fig. 2 (not shown), the turbine is replaced by two turbines in series, the lowpressure turbine driving the compressor and the high-pressure turbine generating useful power.