Assessment of a high-performance geothermal-based multigeneration system for production of power, cooling, and hydrogen: Thermodynamic and exergoeconomic evaluation

Abstract

The novel multi-generation system is developed to produce power, cooling, and hydrogen. The present work is suggested to employ the geothermal energy to start a Kalina cycle and then with regard to the high temperature of the saturated liquid leaving the Kalina cycle separator, the absorption refrigeration system is employed for providing cooling as a subsystem. Also, an electrolyzer and the power production capacity of the cycle have been utilized to produce hydrogen. The proposed system is evaluated thermodynamically and exergoeconomically, and a parametric study was performed for the following parameters: geothermal heat source temperature (THS,in), the temperature difference in vapor generator 1 (ΔTPP,vg1), the pressure of vapor generator 1 (Pvg1), condenser temperature (Tcon), evaporator temperature (Teva) and ammonia concentration (YB). The governing equations are coded in the EES software. In the base case, the results display that the proposed system is capable of producing 258.6 kW of cooling, and in this case, the thermal and exergy efficiencies and the unit cost of multigeneration are 22.28%, 21.37% and 29.29 $/GJ, respectively. Also, increasing the evaporator temperature does not have a significant effect on power production capacity. Moreover, condenser 1 has the most exergy destruction rate of 65.03 kW.