Investigation Of The Thermal Performance Of Organic Liquids And Therminol Oils On The Energy Efficiency And Exergy Of The Flat Plate Solar Collector

The flat plate solar collector as a heat exchanger is responsible for absorbing the radiant energy of the sun and transferring heat to the working fluid. Water and air are among the most common fluids that flow as the working fluid among these collectors. Considering that efficiency is one of the most important criteria in the evaluation of these collectors, in this study, four fluids from the group of organic liquids and therminol oils were selected and their thermal performance was investigated on the efficiency of a flat plate solar collector. The results obtained in this article show that organic liquids are more efficient compared to therminol oils and have better performance in absorbing heat from the collector and transferring it to the working fluid, and the reason for this is the lower specific heat of organic liquids. It is raised at working temperature. Also, with the increase in the intensity of solar radiation, the energy efficiency and exergy of the collector will decrease and the amount of heat transferred from the working fluid to the collector will increase, and with the increase of the ambient temperature, the exergy efficiency and useful exergy of the collector will decrease. The average values of energy efficiency and exergy due to the choice of working fluid in this design show that organic liquids can be the best working fluid in these type of collectors after water.