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

Abstract

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 αab, end reflection plane reflectivity ρr, solar declination angle δ and solar angle ω 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 δ 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 ω in range of 0–60°. Moreover, the UF increases as αab decreases when other receiver parameters are constant for the δ of 0–8°. The ρr has a limited effect on the UF until δ becomes relatively larger and ω becomes relatively smaller. Furthermore, ω effects are most significant on the UF, followed by δ, f and αab. Setting a suitable f is the most economical and effective way to improve the UF.

Optical Performance Comparison of Different Shapes of Cavity Receiver in the Fixed Line-Focus Solar Concentrating System

“…The proposed method carried out in this research has been validated against the experimental work in our previous works [3,4], see Figure 4. After designing an optical model and setting up the TracePro ® software, the results of both works were compared, and a good agreement was achieved.…”

“…The symmetry plane of the linear Fresnel lens and the cavity receiver inner wall form an intersection line, and ∆f represents the distance between the intersection line and the focal line. The energy flux distribution of the focus facula shows that the energy flux density in the main facula is much higher than that in the side facula [3,4]. The energy flux density of the focus facula is negatively related to the distance between the focal plane and the focal line.…”

“…According to the previous work of our team [3,4], the θ in FLSCS shown in Figure 1, is determined by the following formula:…”

“…Sustainability 2022, 13, x FOR PEER REVIEW 4 of 25 model and methodology can be extrapolated in other countries by modifying the design parameters and operating conditions. According to the previous work of our team [3,4], the θ in FLSCS shown in Figure 1, is determined by the following formula:…”

“…It is utilized to heat the HTF in the cavity receiver. Note that the FLSCS can provide a relatively high optical efficiency for a whole year running based on the lens element's simple periodic slip adjustment [3,4]. The cavity receiver is fixedly installed in the system, which causes its structural parameters to have a significant impact on the system's optical performance during the sun-tracking process of the solar concentrator.…”