Performance investigation of a solar-powered adsorption-based trigeneration system for cooling, electricity, and domestic hot water production

Abstract

In this paper, a theoretical investigation of a solar-powered adsorption-based trigeneration system under the climate conditions of Alexandria, Egypt has been performed. The system is intended to provide the required cooling, electricity and domestic hot water (DHW) loads for a building in Alexandria throughout the year. The system comprises commercial Photovoltaic/Thermal (PVT) and Evacuated tube thermal solar collectors (ETC) for electricity production and solar thermal energy capture. A single stage double-bed silica gel/water pair-based adsorption chiller is utilized for cooling production during the summer. During winter, the captured solar thermal energy is used to provide the required DHW needs. Four different configurations of ETC-only or PVT-only solar collectors in parallel or series connection, named Conf-1 to Conf-4, have been proposed to achieve the best system performance. A novel hybrid configuration Conf-5 from ETC and PVT collectors is proposed to combine the advantages of both collector types. System performance parameters such as average cyclic cooling capacity, coefficient of performance (COP), generated electric power and overall system efficiency have been estimated for all configurations under investigation. The results of the present study show that the month of August and February have the best system performance in summer and winter, respectively. Conf-3 with ETC-only in parallel connection has the best average cooling capacity and COP of about 7.66 kW and 0.382, respectively. The month of July has the maximum electrical power generation for all three configurations containing PVT collectors with total electrical energy generation of 81.7, 78.8 and 39.9 kWh/day for Conf-1, Conf-2 and Conf-5, respectively. The average overall system efficiency for all configurations in August are about 0.315, 0.303, 0.288, 0.285 and 0.313, respectively.