Thermodynamic and thermoeconomic analysis of a novel ammonia-water mixture combined cooling, heating, and power (CCHP) cycle

Abstract

In this research, a new ammonia-water mixture CCHP system driven by a LTHS is proposed which is a modified version of a Kalina cycle. Feasibility investigation of the recommended system is studied based on thermodynamic and thermoeconomic balance equations for performance assessment of thermal systems. the energy efficiency, exergy efficiency, and overall unit product cost are computed 49.83%, 27.68%, and 198.3 $/GJ, respectively. Also, condenser 2 is characterized as the main contributor to irreversibility of the recommended trigeneration system by exergy destruction ratio of 32.03%. Moreover, a thorough sensitivity study is carried out to attain higher energy efficiency by raising the evaporation temperature and basic NH3 concentration or by reducing the separators pressure, heating unit temperature, and terminal temperature difference (TTD) of vapour generator. From exergy perspective, it is figured out that higher exergy efficiency may be achieved by raising the separator 1 pressure, and TTD of vapour generator or by reducing the separator 2 pressure, evaporation temperature, heating unit temperature, and basic NH3 concentration. Also, it is proven that the overall cost of the cycle can be peaked with evaporation temperature, while can be maximized with separator 1 pressure and basic ammonia concentration.