Feasibility of a hybrid BIPV/T and thermal wheel system for exhaust air heat recovery: Energy and exergy assessment and multi-objective optimization

In this paper, a numerical study is conducted to examine the energy and exergy performance and multi-objective optimization of a novel exhaust air heat recovery system made up of a building integrated photovoltaic/thermal (BIPV/T) collector and a thermal wheel (TW) system. The innovative BIPV/T-TW system is capable of pre-heating/pre-cooling the ambient fresh air in winter/summer and also producing electricity. Comparisons are carried out on the basis of energy and exergy by considering three different exhaust air heat recovery systems including the BIPV/T-TW system, the conventional BIPV/T collector, and the convectional TW system. It is observed that the BIPV/T-TW system has the best energy performance among the considered systems in all months of the year, while its exergy performance is lower than the BIPV/T system. Then, the multi-objective optimization technique is utilized to obtain the optimal values of geometric and operating parameters in order to maximize the annual useful energy and exergy obtained from the BIPV/T-TW system. It is found that annual useful energy and exergy gained by the optimized system is 196.31 MWh and 30.15 MWh, which is 563.8% and 1394.1% higher than the un-optimized system, respectively.