Numerical simulation of solar parabolic trough collector with twisted tape insertion shielded within inner cylindrical tube

In this study, the effects of variations in geometrical parameters of shielded twisted tape within the inner cylinder of the absorber tube on the performance enhancement of the parabolic trough collector (PTC) have been investigated. The objective is based on the prediction of the optimized value of geometrical parameters for the modified parabolic trough collector (MPTC) showing the best thermal performance among them. Numerical simulation techniques with Ansys-Aim2020R1 have been used for this investigation. It is desired to determine whether it is advantageous to use inner shielding around the inserts within the absorber tube; and if so, which geometrical parameter plays a crucial character in the prediction of the best possible thermal performance of the system. It was found that with a twisted tape thickness of 0.002 m, twisted tape gap of 0.001 m, inner cylinder center distance of 0.020 m, and the number of twists of the twisted tape of 50 turns the PTC has shown the best possible performance of the system. These findings reflect optimized geometrical parameters of the twisted tape insert shielded by an inner cylindrical tube. The thermal efficiency (η) of the MPTC was found to be 86.5% and approximately 2.063 times that of the conventional PTC. It is a novel endeavor regarding the approach of utilizing the shielding around the inserts within the absorber tube.