Thermal management of high concentrator solar cell using new designs of stepwise varying width microchannel cooling scheme

Abstract

High concentrator photovoltaic (HCPV) system are generally exposed to high solar concentration ratios and reach high temperatures. An advanced cooling technique is compulsory to attain the highest net output power along with the safe operation of the system components. Different designs of stepwise varying width microchannel heat sink are investigated in this study. The main purpose of this study is to investigate the influence of the channel geometry of longitudinal rectangular internal fins and different water inlet mass flow rates on the performance of an HCPV system. A three-dimensional thermal model is developed and used to compare the performance of four different designs of stepwise varying width microchannel heat sinks. These designs are compared with the conventional multichannel heat sink design. The results show that the heat sink design and the coolant mass flow rate have a significant impact on the cell temperature, electrical cell efficiency, system thermal efficiency, electrical exergy efficiency, thermal exergy efficiency, total exergy efficiency and thermal resistance of the heat sinks. For instance, using one of the proposed stepwise varying width microchannel heat sink at solar concentration ratio of 1000 suns and increasing the coolant flowrate from 25 to 1000 g/min decreased the solar cell temperature from around 71.7° C to 40° C with solar cell temperature non-uniformity decreased from 15.5 °C to 9 °C respectively.