Dynamic modelling, exergy assessment and optimisation of a novel solar-driven trigeneration system

In this paper, a solar-driven trigeneration cycle is investigated to produce electric power, refrigeration power and domestic hot water in a cascade organic Rankine cycle (ORC), absorption refrigerating accompanied by an ammonia turbine and a heat recovery cycle, respectively. A dynamic modelling is conducted to evaluate the amount of solar radiation absorbed by the parabolic trough collectors, their optical efficiency and operating fluid properties during the day using the code developed in MATLAB software. An exergy analysis is then performed. As a result, ORC heat exchanger and heat recovery heat exchanger are the major sources of the exergy destruction, respectively, destroying approximately 55.5% of total exergy fed to the system. Moreover, the mean energy and exergy efficiencies are calculated to be about 49.3% and 10.4%, respectively, during the day. Also, the parametric study and optimisation by genetic algorithm show 2.62% and 3.27% increase in the energy and exergy efficiencies, respectively.