Modeling and comparative analysis of jet impingement cooling and conventional channel cooling for photovoltaic strings

A cooling technique for photovoltaic (PV) string based on jet impingement device is proposed in this study to eliminate non-uniform cooling across the surface of the PV panel. Non- uniformity on the PV panel arises due to the uneven solar flux distribution and temperature variations across the cell. This study identifies water jet impingement cooling as a promising solution to provide uniform cooling of PV panels for the climatic data of Middle Eastern region. The complete cooling model incorporates optical, radiation, thermal, electrical and jet cooling model for the overall performance analysis of the PV system. Jet impingement cooling model for PV string is developed in this paper to carry out the heat transfer analysis for single and multiple jet nozzles to predict the cell temperature, power output and conversion efficiency of PV strings. Detailed thermal model based on energy balance approach is also developed to assess the effect of cell temperature on the PV string using average heat transfer correlations. Finally, a comparative analysis is carried out for rectangular channel heat exchanger and jet cooling of PV strings subjected to the conditions of Dhahran. The results reveal that the jet cooling has higher efficiency, minimum cell temperature and temperature uniformity.