Performance investigation of a novel hybrid system for simultaneous production of cooling, heating, and electricity

Abstract

A novel hybrid system (a regenerative gas turbine cycle with a heat exchanger integrated with Kalina and ejector refrigeration cycles) is developed for the simultaneous production of cooling, heating, and electricity. The laws of thermodynamics are applied to investigate the system performance from energetic and exergetic standpoints. A parametric study is presented for studying the effects of some key parameters on four criteria of electrical efficiency (ηelec), thermal efficiency (ηth), primary energy ratio (PER), and exergetic efficiency (ηex). The key parameters include compressor pressure ratio, gas turbine inlet temperature, ammonia mass fraction in basic ammonia/water mixture, vapor generator pressure, the pinch-point temperature difference of the heat exchanger (which connects Kalina and ejector sub-cycles), and evaporator temperature. Results of the modeling procedure at the base conditions areηelec = 37.87%, ηth=36.55%, PER=74.42% andηex = 38.85%; also, the produced cooling, heating, and power are 164.7 kW, 836.85 kW, and 1038 kW, respectively. The combustion chamber and evaporator has also the highest and lowest contribution in total exergy destruction (with exergy destruction rates of 939.2 kW and 0.034 kW), respectively. The parametric study shows that compressor pressure ratio and heat exchanger pinch-point temperature difference have the highest and lowest impacts on the performance criteria, respectively.