Theoretical energy and exergy analysis of a combined cooling, heating and power system assisted by a low concentrated photovoltaic recuperator

Abstract

Supporting energy generation systems with photovoltaic thermal systems is one of the important issues discussed in the literature. With photovoltaic thermal systems, some of the solar energy is directly converted into electrical energy, and the waste heat generated in the photovoltaic module is used for different purposes (heat source, preheater, etc.). In this study, unlike the literature studies, the integration of the photovoltaic module into a recuperator and its use in a combined cooling, heating, and power generation system was investigated thermodynamically. The fossil-fueled energy generation system consists of a Brayton cycle, an organic Rankine cycle, and an absorption refrigeration cycle. The photovoltaic recuperator was placed in the organic Rankine cycle to enhance cooling, heating, and electricity generation. The thermodynamic analyses were performed for different concentration ratios, direct normal irradiation values, mass flow rates, module lengths, and fluid saturation pressures. For the photovoltaic recuperator use, depending on the parameter values, enhancements were achieved in the range of 0–141% for cooling capacity, 32–35.5% for heating capacity, and 1.6–2.1% for net power output. Thus, the overall energy efficiency of the system increased. However, the low contribution of the photovoltaic recuperator to exergy output and the high exergy destruction rate in the photovoltaic recuperator caused the overall exergy efficiency of the system to decrease. The results showed that the location of the photovoltaic recuperator in the combined cooling, heating, and power generation system provided enhancements in a greater number of system outputs, given the results of the literature studies.