Significantly enhanced temperature uniformity and prolonging lifespan in a novel concentrated photovoltaic/liquid-flow ionic thermocell hybrid system through tapered-channel thermal management

The concentrated photovoltaic and liquid-flow ionic thermocell (CPV-LITC) hybrid system can effectively reduce the temperature of PV module while simultaneously enhancing the electrical power output. However, the temperature uniformity of PV would inevitably deteriorate as the convective heat transfer decreases along the direction of electrolyte flow within LITC. The maximum temperature deviation of PV can reach as high as 15.8 K, which may significantly threaten its electrical efficiency and operational lifespan. Herein, a novel CPV-LITC hybrid system with tapered-channel thermal management was proposed to enhance the temperature uniformity and operational lifespan of PV module. The effects of the tapered-channel structure, the channel inlet-to-outlet area ratio (Sin/Sout) and the direction of electrolyte flow on the temperature distribution and electrical power output of CPV-LITC hybrid system were systematically investigated through a three-dimensional transient numerical model. A photovoltaic lifespan evaluation model was introduced to comprehensively assess the impact of temperature uniformity on the lifespan of PV through long-term and seasonal analysis. Results show that compared to the Sin/Sout = 1:1 channel configuration, the average temperature of PV can be reduced by 6.5 K under the Sin/Sout = 3:1 condition, while its temperature uniformity and allowable concentration ratio improved by 7.9 % and 33.7 %, respectively. Under a typical meteorological year condition, the optimal tapered channel design can significantly extend the lifespan of PV modules by up to 19.6 %. The CPV-LITC system incorporating tapered-channel thermal management demonstrates notable advantages in cost-effectiveness, high electrical power output, and operational flexibility.