Thermal optimization and exergy efficiency of two new parabolic solar collectors using response surface methodology

Abstract

This research examined problems regarding enhancement of the thermal efficiency, performance examination and optimization of parabolic trough solar collector (PTSC) based on implementation of TiO₂ nanofluids and new design of two collectors. This new design aims to enhance efficiency of PTSC by increasing the amount of absorbed radiation or reducing the heat loss from the collector. This research examines the heat transfer performance of PTSC influence of different baffle types, including circular and trapezoidal shapes, integrated with turbulent nanofluid flow in the receiver tube. The inlet temperature of the heat transfer fluid was set at 120 °C, with the outlet temperature fluctuating between 250 °C to 450 °C. 3D computational fluid dynamics simulations using Ansys Fluent software and optimization process based on response surface methodology (RSM) using Design Expert analysis investigated entropy, thermal power, exergy efficiency, thermal efficiency and effective Prandtl number (Pr) for various solar panel configurations. The results illustrate the new design using circular collectors integrate with Nano particle increases the pressure drop but significantly improves the heat rate up to $q=1075.6w/m^2$. Also, the performance of exergy efficiency improved for the collector mounted circular baffle by $30.45\%$. Moreover, absorbed heat rate for solar concentrator collectors mounted circular baffles is $72.2\%$ more than the trapezoid baffles. Moreover, the maximum and minimum thermal efficiency for collector mounted circular baffle are 71.7221 and 53.8437 respectively, also, for trapezoid baffles are 69.5789 and 64.0418, respectively. Finally, the max rate of Re is $6.95\%$ for PTSC including trapezoidal baffles. Thermal power collector with circular baffle has performed up to 4 % more than trapezoidal baffles. The maximum thermal efficiency is $4.7\%$ for PTSC mounted circular baffles.