Abstract
Abstract This study investigates the optimization of physical parameters in a parabolic trough collector receiver unit to improve its thermal and optical performance. The parameters include the transmissivity, reflectivity, absorptivity, emissivity and thermal conductivity of the outer cover and absorber pipe. This study utilizes a novel experimental design and a simulation model that accounts for the infrared reflectivity inside the receiver. The simulation results were validated by the experimental data, with a maximum deviation of 8%. The study analyses the effects of varying the physical parameters on the heat transfer fluid temperature, total plant efficiency, temperature profiles, temperature gradients and thermal stress. The study finds that increasing the reflectivity and decreasing the emissivity of the outer cover and the absorber pipe significantly enhance the performance, with maximum increases of 25.8% and 26.5% in total efficiency, respectively. The study also finds that increasing the thermal conductivity of the absorber pipe reduces the temperature gradients and thermal stress, with maximum decreases of 42.2% and 29%, respectively. This study provides valuable insights for optimizing the receiver design and operation in solar–thermal systems.