Simulation assessment of the absorber tube of a solar parabolic trough collector using two types of spiral indentations

Abstract

Abstract Effective solar energy usage and solar energy gathering have grown in prominence due to the dearth of fossil fuels in recent years. In the current research, the absorber tube of a parabolic trough solar collector having two types of indentations has been considered and numerically simulated. For these studies, a steady heat flux has been considered on the tube. Fluid flow in the tube is subjected to turbulence and for which, the k-RNG turbulence model is utilized. It is revealed that the Nusselt number for absorber tubes with trapezoidal indentations is found to be 72.11, indicating superior thermal efficiency compared to 65.59 for rectangular indentations. However, trapezoidal indentations also result in a higher friction factor leading to a pressure drop of 247.21 Pa than rectangular indentations having a pressure drop of 159.81 Pa. The selection of either rectangular or trapezoidal indentations is contingent upon the particular demands of the application, including factors such as effectiveness, cost, and operational limitations. In situations when it is crucial to minimize energy consumption for fluid flow, the use of a rectangular indentation may be more advantageous. However, if other variables like as heat transfer efficiency take precedence and the extra energy expenditure for pumping can be rationalized, then the trapezoidal indentation may be the preferable option.