effect of covering aperture of conical cavity receiver on thermal performance of parabolic dish collector: experimental and numerical investigations

In this study, the effect of covering the aperture area of a conical cavity receiver with an ultra-white glass on operational parameters of a parabolic dish collector (pdc) was numerically and experimentally investigated under climate conditions of tehran (35.44° n latitude and 51.10° longitude). the main components of the experimental setup include a dish reflector, a conical cavity receiver, heat transfer fluid (htf), hydraulic and cooling cycle, and a sun tracker. for this purpose, a conical cavity receiver with an ultra-white glass cover on its aperture was numerically modeled in fortran software. during the evaluation, environmental parameters including ambient temperature, solar radiation, and wind speed were considered as inputs of the model. the results revealed fair agreement between the numerical and experimental data with the maximum error of approximately 4.63 % and 7.89 % for receivers with and without the glass cover on the aperture, respectively. for a steady-state analysis, the mean values of useful energy (q̇u) absorbed by the receiver were calculated as 1,253.25 w and 987.68 w, while thermal efficiency (ηth) of the receiver was calculated as 52.61 % and 40.69 % for receivers with and without glass cover, respectively. the results revealed that both ηth and q̇u followed a similar trend of the variations in the htf’s temperature between the inlet and outlet of the receiver. also, the overall heat loss coefficient (ul) and the collector heat removal factor (f𝑟𝑟) were calculated as 420.76 w/m2°c and 0.62 for the conical cavity receiver with the glass cover.