Thermal performance evaluation of a parabolic trough collector receiver: A numerical study of three heat exchanger configurations

In this study, a numerical investigation of the performance of a parabolic trough collector receiver is conducted using ANSYS Fluent software. Three receiver configurations (with U-tube, Helical tube, and UU-tube heat exchangers) are studied for different flow rates and inlet temperatures. The maximum outlet temperature is recorded for the lowest flow rate and inlet temperature. Thus, the helical configuration shows an outlet temperature enhancement of 5.03% compared to the UU configuration and 5.43% compared to the U configuration. The highest efficiencies of 92.1%, 84.7%, and 74.5% are recorded for the helical, UU, and the U configurations, respectively, at high flow rate and low inlet temperature. The temperature difference and distribution within the receiver are examined at three specific cross-sections. For the helical configuration, reductions in the transverse temperature gap of 77.34% and 66.91%, compared to the U-tube and UU-tube, respectively, are reported at the lowest flow rate. However, the helical configuration exhibits the highest overall receiver temperature gap, measuring 12.59% and 21.57% higher than those of the U and UU configurations, respectively. The investigated receiver configurations provide an effective approach for enhancing the thermal performance of PTC systems, leading to more efficient and durable designs.