Evaluation and optimisation of receiver height in a compound parabolic collector with low acceptance angle

This research presents the method of finding an optimised location of a tubular receiver for a compound parabolic collector (CPC) with 6° acceptance angle. Due to low acceptance angle, reflected rays concentrate below the focus of a parabola. Graphical ray tracing (GRT) approach is implemented to execute the optical analysis with and without manufacturing error in the collector. It is performed on collector–receiver combinations by varying receiver height below the focus and they are compared on the basis of utilised area and projection ratios. The ideal cases of collector–receiver combinations which contribute high utilisation and projection ratio are selected and verified with the camera target method (CTM) performed on the actual set-up. It is built for water heater application to validate the results obtained from GRT and CTM. The thermal performance of CPC at various receiver heights is compared by thermal efficiency and therefore the optimum receiver height is concluded.