Energy, Vol.34, No.9, 1364-1371, 2009
Study of a deaerator location in triple-pressure reheat combined power cycle
Deaerator is an essential open feed water heater in the steam bottoming cycle to improve the efficiency and also to remove the dissolved gasses from the feed water. Heat recovery steam generator (HRSG) plays a key role on the performance of the combined cycle (CC). In this work, attention has been focused to improve the performance of a triple pressure (TP) CC with a deaerator location. In this work, two options for deaerator location, one at condenser (deaerator-condenser) and the other in between low pressure (LP) and intermediate pressure (IP) heaters have been studied to increase the heat recovery from the gas turbine exhaust. The compressor pressure ratio is not fixed initially and evaluated from HRSG inlet condition. The LP and IP in HRSG have been evaluated from the local flue gas temperature to get the minimum possible temperature difference in the heaters. The results show that the deaerator placed in between the LP and IP heaters, gives high efficiency compared to a deaerator-condenser arrangement. The optimum conditions for the HRSG, deaerator and steam reheater are evaluated through the thermodynamic study. The results are validated by comparing with the published results. (C) 2009 Elsevier Ltd. All rights reserved.
Keywords:Exergy analysis;Gas turbine;Heat recovery steam generator;Steam cycle;Thermodynamic analysis