Performance assessment of a novel system using parabolic trough solar collectors for combined cooling, heating, and power production

In this study, performance assessment of a novel system based on parabolic trough solar collectors and an organic Rankine cycle for combined cooling, heating and power (CCHP) is presented. In this system, a portion of the waste heat is used for heating through a heat exchanger and the other portion is used for cooling through a single-effect absorption chiller. This study considers three modes of operation: a solar mode, which is characterized by a low-solar radiation; a solar and storage mode, which is characterized by a high-solar radiation; and a storage mode, which is the operation of the system at night time through a thermal storage tank subsystem. To assess the performance improvement of the present system, three further cases are considered: electrical power, cooling-cogeneration, and heating-cogeneration. This system is designed to produce 500 kW of electricity. Different output parameters - efficiency, net electrical power, and electrical to heating and cooling ratios - are examined in this study. This study reveals that the maximum electrical efficiency for the solar mode is 15%, for the solar and storage mode is 7%, and for the storage mode is 6.5%. Alternatively, when CCHP is used, the efficiency increases significantly. The maximum CCHP efficiency for the solar mode is 94%, for the solar and storage mode is 47%, and for the storage mode is 42%. Furthermore, this study shows that the electrical to cooling ratio is sensitive to the change in the ORC pump inlet temperature. Therefore, the variation in this temperature could be used as a good control for the amount of the cooling power needed.