Experimental study of the thermal performance of heat storage-integrated solar receiver for parabolic dish collectors.

Abstract

Parabolic dish collectors (PDC) efficiently produce hot fluids for medium-temperature applications. Thermal energy storage employs phase change material (PCM) due to its high energy storage density. This experimental research proposes a solar receiver for the PDC with a circular flow path surrounded by PCM-filled metallic tubes. The selected PCM is a eutectic mixture of KNO3 and NaNO3 (60%:40% by wt). At a peak solar radiation of about 950 W/m2, the receiver surface reached a maximum of 300°C. The modified receiver is tested outdoors with water as a heat transfer fluid (HTF). The energy efficiency of the proposed receiver is about 63.6%, 66.8%, and 75.4% for the HTF at 0.111kg/s, 0.125kg/s, and 0.138kg/s, respectively. The receiver's exergy efficiency is recorded at about 8.11% at 0.138kg/s. The receiver with a maximum reduction of CO2 emission is about 1.16 tons recorded at 0.138kg/s. The exergetic sustainability is analyzed using key indicators, like the waste exergy ratio, improvement potential, and sustainability index. The proposed receiver design with PCM effectively produces maximum thermal performance with a PDC.