Performance evaluation of a jet impingement bifacial photovoltaic thermal solar air collector (JIBPVT)

Abstract

Jet impingement is a promising cooling mechanism to increase the rate of heat transfer in solar collector. However, the investigation on the effects of impinging air jet on the energetic, thermo-electro-hydraulic, exergetic and economic performance of a bifacial PVT with different packing factors are entirely unclear. This study demonstrates a Jet Impingement Bifacial Photovoltaic Thermal Solar Air Collector (JIBPVT). Jet plate reflectors with different geometric configurations are proposed to enhance the cooling and light absorption at the rear part of the bifacial PV module. Performance evaluation for JIBPVT has been carried out by two methods, which are modeling simulation and experimental work. In the modeling part, a one-dimensional steady-state analytical heat flow model is formed to develop the energy balance equations between each component of the system. After the energy balance equations of the collector is developed, a comprehensive analysis is carried out by the simulation using MATLAB. In the experimental part, a prototype is built to obtain the experimental data from the field. The location for the experiment is in the laboratory of Solar Energy Research Institute, National University of Malaysia, Bangi, Selangor, Malaysia. The experiment was conducted for seven months. After the completion of data collection, the modeling data is validated with the published results and experimental data, and the data validation shows a good agreement between them. The relationship between the energetic, thermoelectro- hydraulic, exergetic and economic performance with each of the variable design and operating parameters was investigated. The results demonstrated that higher packing factor of bifacial PV module increases the absorption of solar irradiation and electricity generation, which leads to higher thermal and electrical outputs. Besides, larger spacing between jet holes on jet plate reflector decreases jet interferences and crossflow effects, resulting in a higher heat transfer rate. Hence, the optimum design of the proposed system is JIBVPT with packing factor of 0.66 and 36-holes jet plate reflector. The maximum thermal, electrical, and total energy efficiencies of JIBPVT are 64.45, 11.15, and 93.8%, respectively. At Re = 9929 and Re = 5667, respectively, the maximum thermal energy gain and electrical energy output are reached. JIBPVT has the greatest thermal, electro, and thermo-electro-hydraulic efficiencies of 57.3, 10.36, and 83.93% , respectively. The highest exergy efficiency of JIBPVT with packing factors of 0.66 and 36-hole jet plate reflector was 11.88% under solar irradiance of 900 W/m2, and mass flow rate of 0.025 kg/s. The highest exergy input, exergy destruction and improvement potential of the proposed system are 402.81 W, 345.62 W and 304.78 W, respectively. Furthermore, the CBR and CBRX variations of JIBPVT vary from 0.0946 to 0.311 and 0.742 to 2.826, respectively, with an average of 0.2 and 1.44. Moreover, by adopting JIBPVT to manufacture energy rather of fossil fuels, yearly carbon dioxide emissions may be decreased by around 1.45 and 0.18 tons, saving RM84.22 and RM10.65 annually in terms of energetic and exergetic, respectively. In addition, the proposed JIBPVT outperformed the other systems in literature reviews. By comparing to JIPVT and BPVT analytically, JIBPVT has a better performance among these air-based PVT. As a consequence, JIBPVT is an extremely efficient solar collector with a high thermal and electrical output.