THERMAL EVALUATION OF CAVITY RECEIVER USING WATER/PG AS THE SOLAR WORKING FLUID

In this study, a parabolic dish concentrator with a cavity receiver was investigated. Water/ Propylene Glycol (PG) was used as the solar heat transfer fluid. Thermal numerical modelling was developed for prediction of the cavity receiver performance. The water/PG in different volume fractions (VF) of the PG was examined consist of 0%, 25%, 50%, and 55%. The working fluid inlet temperature is investigated in ranging 0°C to 100°C. The results revealed that the thermal efficiency and the cavity heat gain decreased by increasing the GP volume fraction. The pressure drop and pumping work demand decreased by increasing the working fluid inlet temperature as well as decreasing the PG volume fraction in the pure water. Consequently, the pure water had the lowest amount of the pressure drop among the investigated working fluids. The cavity surface temperature increased by increasing the working fluid inlet temperature as well as increasing the PG volume fraction in the pure water. Consequently, the application of the higher amount of PG is recommended for the Bryton cycle.