DOI: 10.5176/2251-189X_SEES15.47
Authors: Mayank Maheshwari and Dr.Onkar Singh
Abstract:
Gas and steam combined cycle has Brayton cycle and Rankine cycle as topping and bottoming cycles respectively. Gas based topping cycle has flue gases leaving at high temperature which are utilized in heat recovery steam generator for steam generation. The steam thus generated is used for running steam turbine in bottoming cycle. It is seen that the heat recovery steam generator offers reasonable heat recovery from flue gases but the further scope of heat recovery is possible as the temperature variation profile of gas does not match with that of steam generation. The use of ammonia in place of steam as working fluid offers a good matching of temperature profile of flue gas and ammonia and thus has capability to offer effective utilization of waste heat. The significance of present work is to analyze the effect of ammonia mass fraction, cycle pressure ratio and turbine inlet temperature in Kalina cycle used in combined cycle. The results show that upon increasing the ammonia mass fraction the efficiency of the cycle decreases up to ammonia mass concentration of 0.7 but beyond that the efficiency starts increasing. It also indicates that by utilizing the solar heating, there occurs a heat gain up to 5{6e6090cdd558c53a8bc18225ef4499fead9160abd3419ad4f137e902b483c465} as compared to the cycle arrangement without solar heating for any given operating parameters.
Keywords: Kalina cycle, Ammonia mass fraction, Gibbs free energy
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