Авіаційно-космічна техніка та технологія (Aug 2017)
COMPUTER SIMULATION OF WASTE HEAT RECOVERY GAS TURBINE UNIT INTAKE AIR COOLING SYSTEM WITH PRODUCING OF CONDENSATE
Abstract
The heat-humidity processes in the two-stage air cooler of combined type with water stage of precooling air to the temperature above 15 °C and refrigerant stage of further deep cooling air to the temperature about 10 °C by utilizing the exhaust gas waste heat in the absorption lithium-bromide chiller as the high temperature cooling stage and refrigerant ejector chiller as the low temperature cooling stage of the combined thermotransformer for gas turbine intake air cooling has been analyzed for daily changing ambient air temperatures and corresponding heat loads on the stages as consequence. The processes of producing the condensate as a subproduct of gas turbine unit intake air two-stage cooling were simulated for two variants of design heat loads upon air cooler stages: for approximately equal heat loads upon the air cooler stages and for more than twice decreased heat load upon the high temperature cooling stage as compared with a heat load upon the low temperature cooling stage. The data about hourly amount of condensate extracted in each air cooler stage summed up over days and month and its temperature were calculated. The results of calculation have shown that the temperature of condensate received in the refrigerant low temperature cooling stage is about 11 °C and the temperatures of condensate received in the high temperature cooling stage with a chilled water temperature of 7 °C from absorption lithium-bromide chiller is about 15 °C that is the first one is lower by about 4 °C. It was also shown that the temperature of condensate from both stages of a combined twostage air cooler remained nearly unchangeable during July. A conclusion about separate rejecting condensate from high and low temperature cooling stages of air cooler was made. The reserves of refrigeration capacity of absorption lithium-bromide chiller and refrigerant ejector chiller due to daily changeable heat loads were analyzed from the point of their use for cooling of condensate to the temperature of about 7 °C and its application as a coolant for high temperature cooling stage of gas turbine intake air cooler.
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