GB835245A - Method of carnot-izing steam cycles - Google Patents

Abstract

835,245. Power-generating systems; turbines. SONNEFELD, G. June 13, 1956 [June 13, 1955], No. 18269/56. Classes 110 (3) and 122 (3). Relates to means for increasing the thermal efficiency of a steam cycle and consists in a steam power plant having a main steam cycle and an additional steam cycle superimposed thereon, the additional cycle having a maximum pressure less than that of the main cycle and a minimum pressure greater than that of the main cycle and the exhaust heat of the additional cycle being used to preheat, evaporate and superheat the main cycle condensate when it is at the maximum pressure of that cycle. In the arrangement shown in Fig. 3, main cycle condensate from condenser Ko is pumped by pump Fp through feed water heaters Ph1, where it is heated by bled steam from turbines TN and TV, preheated, evaporated and superheated in preheater Ph2, evaporator B and superheater S, respectively, by the exhaust steam from turbine T, further superheated in superheater SF by flue-gases in chamber H, expanded in turbine TA, reheated in superheater SR and finally expanded in turbines T and TN which provide the plant output. In the superimposed additional cycle steam discharged from the compressor K is superheated by flue gases at SR with the exhaust steam from turbine TA, expanded in turbine T and passes with loss of heat through superheater S, evaporator B and preheater Ph2 to the compressor K. The turbine TV is supplied with steam from the T-K circuit upstream of the compressor K. In the arrangement shown in Fig. 4 compressed air from an air compressor KL, driven by an air turbine TL1, is heated by flue gases in a heater SA, expanded in the turbine TL1 and further expanded in a separate air turbine TL2 coupled to the turbine TA. In a modification, Fig. 6 (not shown), a vaporizing drum and steam circulating pump are added so that the further cycle may be shut off, if desired, e.g. for overhauling components thereof, and the plant operated on a normal steam cycle. Temperature-entropy diagrams of the cycles are shown and described.