Evaluation of a Solar Combined Heating and Power Water- Ammonia Cycle based on Energy, Exergy and Exergoenvironmental analyses

This work proposes and models a new cogeneration to produce the power and heating simultaneously from the energy, exergy and environmental impact concepts. The ammonia- water is applied as the working fluid and parabolic trough collectors are selected to provide the required energy of system by absorbing the solar insolation. In order to specify the required energy in bottoming cycle, an auxiliary boiler is installed in solar subsystem consuming natural gas. Energy modelling indicates that the energy efficiency of 36.82% for the desired system. According to the exergy analysis, the total product exergy is 2195 kW. Key parameters namely, the vapour generator pinch temperature difference, mass flow rate, ammonia concentration and turbine inlet and outlet pressures are investigated on the energy and environmental impact of system. Parametric study indicates that the increment of inlet and outlet pressure, mass flow rate and ammonia concentration have positive effect on the environmental impact of system.