Experimental and theoretical analysis on a linear Fresnel reflector solar collector prototype with V-shaped cavity receiver

摘要

A linear Fresnel reflector (LFR) solar collector with modified V-shaped cavity receiver was investigated both experimentally and theoretically in this paper. Simplified ray tracing technique was employed to optimize the optical design of the LFR system. The Monte Carlo ray tracing method was used to predict the optical performance of the proposed LFR system. A 2D mathematical model was developed to investigate the effect of receiver surface temperature on the overall heat transfer coefficient which reflects the thermal performance of the modified linear cavity receiver. CFD simulation was carried out for the modified cavity receiver treated at various surface temperatures within a range of 90-150℃, by taking into account the conductive, convective and radiative heat losses. Experimental results show that the overall heat loss coefficient varied from 6.25 to 7.52 W/m~2 K for the tested surface temperature range, with an average deviation of about 12% when compared with simulation results. Also, at higher surface temperatures, heat loss through radiative mode was predominant and the system stagnation was found to be about 260℃ with optimal operating temperature of about 121℃. The thermal efficiency decreased from 45% to 37% as the average surface temperature increased from 90℃ to 150℃.