Effects of Receiver Parameters on Solar Flux Distribution for Triangle Cavity Receiver in the Fixed Linear-Focus Fresnel Lens Solar Concentrator

The objective of the study is to investigate and optimize the solar flux uniformity of a fixed linear-focus Fresnel lens solar concentrator using a triangle cavity receiver. The effects of receiver parameters including the vertical distance from the cavity opening plane to the Fresnel lens f, receiver internal surface absorptivity alpha(ab), end reflection plane reflectivity rho(r), solar declination angle delta and solar angle omega on the uniformity factor (UF) of a triangle cavity receiver were carried out. The effects of receiver parameters are evaluated with a significance test of critical factors. The results showed that the increase in f and delta would result in an increase in the UF. The average UF with f = 600, 625, 650, 675 and 700 mm, respectively, are 0.5030, 0.5858, 0.6337, 0.6576 and 0.6784 for omega in range of 0-60 degrees. Moreover, the UF increases as alpha(ab) decreases when other receiver parameters are constant for the delta of 0-8 degrees. The rho(r) has a limited effect on the UF until delta becomes relatively larger and omega becomes relatively smaller. Furthermore, omega effects are most significant on the UF, followed by delta, f and alpha(ab). Setting a suitable f is the most economical and effective way to improve the UF.