Thermal management of concentrator photovoltaic systems using new configurations of phase change material heat sinks

摘要

A new concentrator photovoltaic system integrated with phase change material heat sink is developed to achieve low and uniform temperature distribution along the solar cell. The developed system includes a phase change material enclosure with different over height ratios, defined as the ratio between the over height length of the phase change material heat sink to the solar cell length. Subsequently, four different over height ratios of 0, 20, 40, and 60 % along with three inclination angles of -45 degrees, 0 degrees and 45 degrees at solar concentration ratios of 5 and 10 are investigated. Thus, experimental and numerical investigations have been carried out to investigate the influence of the over height ratio and inclination angle of the phase change material heat sink on the temperature distribution along the solar cell. To assess the performance of the suggested designs of heat sinks, a compendious two-dimensional model of the concentrator photovoltaic cell layers combined with phase change material is developed and numerically simulated. The numerical results are further validated with experimental measurements. These measurements involve transient variation of liquid fraction and the evolution of the local temperature during melting of RT35HC phase change material carried out at different inclination angles of -45 degrees, 0 degrees and 45 degrees. Results indicate that the influence of varying the over height ratio depends on the inclination angle of PCM heat sink. It is found that at an inclination angle of -45 degrees and a concentration ratio of 5, the peak cell temperature reduces from 92 to 74 degrees C, and the temperature uniformity varies from 13.7 to 5.3 degrees C as the over height ratio rises from zero to 60 %. However, at an inclination angle of 45 only, a slight reduction in the peak cell temperature is observed along with a minor improvement of temperature uniformity. Results of the present work can assist in the selection of appropriate phase change material-heat sink design for the required types of solar concentrators.