Thermal performance evaluation of single-evacuated tube compound parabolic concentrator (ET-CPC) with thermosyphon heat pipe solar collector using waste car engine oil (WCEO)

The thermal performance of a single-evacuated tube compound parabolic concentrating (ET-CPC) solar collector integrated with a thermosyphon heat pipe (THP) was experimentally analyzed using waste car engine oil as the heat transfer medium. The collector was designed and fabricated with an acceptance half-angle of 60° and a tilt angle of 45°, ensuring efficient thermal energy transfer while minimizing losses. The solar collector demonstrated high efficiency in utilizing both direct and diffuse radiation, the evaporator temperature reaches above 200°C, even under cloudy or rainy conditions. Under peak solar radiation, the maximum evaporator temperature reached 228.92°C, showcasing the system’s efficiency and adaptability to varying solar intensities. Performance was assessed across varying flow rates from 0.01 kg/s to 0.06 kg/s, with an optimal flow rate, achieving a maximum useful heat gain of 4,358.13 W with an average heat transfer rate of 7,086.81Wh and the maximum thermal efficiency of 45.52% at the flow rate of 0.05 kg/s. The effect of solar radiation on the thermal efficiency gradually increases with increase in the instantaneous efficiency of the collector. The designed solar collector has a thermally stable condition. Utilizing waste car engine oil (WCEO) as the heat transfer fluid (HTF) ensures efficient thermal energy transfer and storage, providing stable heat output and maintaining a consistent temperature. Results indicate the potential of the ET-CPC system for applications such as cooking, drying, and desalination, particularly in regions with intermittent solar radiation.