Heat transfer and performance analysis of SAH having new transverse finned absorber of lateral gaps and central holes

摘要

An experimental work is presented on the performance of solar air heater (SAH) has new designed absorber of finned transverse plate of lateral gaps and central holes. Moreover, a complete heat transfer analysis of the radiation and convection and SAH thermal performance are presented and discussed. The performance of this transverse SAH (TR_SAH) is compared with identical conventional flat plate SAH (FP_SAH) for single (SP) and double-pass (DP) airflow and air mass flow rates (AMFR) of 0.025, 0.05, and 0.075 kg/s. The experimental study is performed under hot climate conditions of Upper Egypt. The findings show that for all studied cases, TR_SAH has higher energy gain, output air temperature, thermal efficiency, and Nusselt number on the absorber plate, thermal-hydraulic performance parameter, and pressure drop compared to FP_SAH. The energy loss and radiation and convection Nusselt number on the TR_SAH glass plate is lower than that of FP_SAH. The maximum TR_SAH energy efficiency of value of about 89% is achieved in the case of DP airflow and high AMFR of 0.075 kg/s, with an enhancement of 24.2% compared to FP_SAH. The higher TR_SAH efficiency at these conditions reflects the optimal TR_SAH absorber design especially at high AMFR and using DP airflow. Despite TR_SAH air pumping power is greater than FP_SAH but it has a negligible effect on net energy gain.