Numerical and Experimental Investigations of an Involute Shaped Solar Compound Parabolic Collector with Variable Concentration Ratio

Solar compound parabolic collector (CPC) systems are considered a viable solution for process and space heating applications in industrial and domestic sectors for low to intermediate temperature ranges. Many CPC profiles have been proposed with distinct optical and thermal characteristics. In this research, an involute-shaped CPC with a variable concentration ratio along its length is developed and analyzed in terms of its optical and thermal performance. The acceptance angle of the collector is linearly increased from 37.5° to 52.5° along its length with corresponding change in the concentration ratio from 4.58 to 5.87 respectively. Optical and thermal analyses are performed using TracePro and Ansys/Fluent software for stationary installation in both east-west (E-W) and north-south (N-S) orientations. The numerical results show about 16% enhancement in optical performance and 7.3% thermal performance of the collector installed in the E-W direction as compared to the N-S orientation. The experimental analysis also confirms that the performance of the developed collector is 4.75% better in E-W installation than in N-S orientation. The comparative analysis shows about a 3.7% deviation between theoretical and experimental results in E-W orientation. It is concluded that the optical and thermal performance of the collector with variable concentration ratio is better in E-W orientation compared to N-S.