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. (C) 2012 Elsevier Ltd. All rights reserved.