Patent GB-564947-A (GB)
Title: Thermal power plant
Filed: 1943-06-07
Abstract: 564,947. Elastic fluid turbines. AKT.-GES. FUR TECHNISCHE STUDIEN. June 7, 1943, No. 9098. Convention date, June 26, 1942. [Class 110 (iii)] The invention deals with regulating means for a thermal power plant comprising one or more turbines 4 driving a compressor 1, which compresses the gaseous working fluid, a supply of heat from an external source 3, and a further turbine or turbines 6 which drives a compressor 9, or another machine, the speeds of the turbines 4-and 6 being independent of one another. The turbine 4 is preferably driven at a constant, or only slightly varying speed, but the turbine 6 may operate over a wide speed range. The ratio between the highest and lowest pressures within the plant circuit remains practically constant. Fig. 1 shows one arrangement wherein gas is compressed in a compressor 1 and passes through a heat exchanger 2, a furnace 3, a turbine 4 driving the compressor 1, a further turbine 6, driving a compressor 9, the gas returning through the heat exchanger 2, a pre-cooler 8 to the compressor. A pressure governor 10 has a piston 11 which is influenced by pressures in a venturi nozzle 12 in the suction pipe of the compressor 9, and actuates a distributing valve 13 to raise or lower a servo piston 14. The latter operates a valve 15 which, on being displaced downwards, allows gas to flow from a high-pressure reservoir 16 into the circuit at 17, whilst on being moved upwards, it allows gas from the circuit to pass into a low-pressure reservoir 18. The piston 11 may be raised by a spring if the quantity of gas delivered by the compressor 9 is small. If the speed of turbine 4 rises, a governor 19 raises a rod 20 and a valve 21 causing a piston 22 to move downwards so that gas byepasses the turbine 4 and flows from a point 24 through a pipe 24<2> into a pipe 5 leading to the turbine 6. If the speed of the turbine 4 falls, the parts move in opposite directions, the valve 23 is raised and gas byepasses the turbine 6 until equilibrium is restored. Instead of byepassing either turbine 4 or 6, gas may be arranged to byepass certain stages of either turbine. The heater 3 may be partly, or entirely byepassed by adjusting valves 28, 29 and using pipes 241, 24<2> or 27<1>, 24<2>. Fig. 2 shows a plant in which gas leaving a heater 40 is divided in a chamber 30 to flow through turbines 33 and 34 in parallel. The position of the governor 19 changing causes the piston 22 to move a throttle valve 36 to throttle the supply of gas passing to either pipe 21 or 32. In a further modification, a piston having its surfaces connected to the venturi 12, is coupled through links to the speed governor on the turbine driving the compressor 1, and also to the servo system controlling the flow to or from the gas circuit of gas in the highpressure and low-pressure reservoirs. Fig. 5 shows an arrangement in which means for temporarily preventing a supply or withdrawal of gas are influenced by the suction and delivery pressures, pN and pH respectively, of the working gas compressor. The piston 51 is under influence on its opposite sides, of pressures in the venturi nozzle, and is linked to a beam 73 resting on pivot points 76, 77. If pH/pN>aN/aH , the beam is turned counter-clockwise around the point 76, and the rod 64 is raised, i.e. the same effect is caused as when the speed of the gas compressor increases. If pH/pN<bN/bH , the beam is turned clockwise around the point 77, and the rod 64 moves downwards. In between these limits, the beam 73 remains stationary, and a point 63 becomes the fixed fulcrum for a lever 54 controlling the servo system and thus the high- and low-pressure reservoir supplies.