Energy Conversion and Management, Vol.176, 39-54, 2018
Thermal and structure analyses of high concentrator solar cell under confined jet impingement cooling
The high solar light concentration onto the photovoltaic cell leads to extremely high cell temperature, which significantly decreases the cell efficiency and degrades its lifetime due to the thermal stresses. One of the main challenges of these types of solar cells is to propose an efficient cooling technique that allows the cells to operate under its recommended operating conditions. Therefore, the focus of this study was to develop a comprehensive three-dimensional model for the high concentrator photovoltaic/thermal (HCPV/T) system. This model comprises a thermal model for a triple-junction solar cell integrated with a thereto-fluid model for four distinct designs of confined jet impingement heat sinks. The results showed that the cell electrical efficiency increased with the coolant flow rate, and sufficient temperature uniformity can be achieved by the jet impingement configurations. Additionally, the use of jet impingement configurations consumed a slight pumping power less than 1% of the generated power in the solar cell. The maximum local temperature of uncooled solar cell was predicted to reach 1360 degrees C under solar concentration ratio of 1000 Suns. Under the same conditions, the single jet design reduced the maximum local temperature to about 65 degrees C with coolant mass flow rate of 50 g/min. It should be noted that the thermal stress substantially decreased with the increasing coolant mass flow rate. Exergetic analysis showed that the single jet design attained the maximum total exergy efficiency of 53.25% at the flow rate of 25 g/min.