Effects of double windows on optical and thermal performance of solar receivers under concentrated irradiation. (15th May 2019)

• Record Type: Journal Article
• Authors: Li, Xiao-Lei; Xia, Xin-Lin; Li, Zhen-Huan; Chen, Xue
• Is Part Of: Solar energy. Volume 184(2019)
• Page Start: 331
• Page End: 344
• Publication Date: 2019-05-15
• Subjects: Double window -- Solar receiver -- Optical and thermal performance -- Concentrated irradiation -- Monte-Carlo Ray Tracing; Solar energy -- Periodicals; Solar engines -- Periodicals; 621.47
• DOI: 10.1016/j.solener.2019.04.016
• Languages: English
• ISSNs: 0038-092X

Abstract

Highlights: Evaluation of a novel double-windowed pressurized volumetric receiver (DW-PVR). A numerical model combining MCRTM and FVM to predict optical and thermal performance. A lower temperature field occurring at the outer window of DW-PVR. DW-PVR showing advantages with greater windows distance and smaller cavity size. Abstract: To fulfill the working condition at high pressure and temperature, a double-windowed pressurized volumetric receiver (DW-PVR) was proposed in this work. A computation model combining Monte-Carlo Ray Tracing method (MCRTM) and Finite Volume method (FVM) was established to evaluate the temperature field, energy losses, and efficiencies of the receiver. The model also includes a gray-band approximation to consider the spectral properties of windows. The performance of receiver with two windows and with single one (SW-PVR) was compared with each other. Based on the model, effects of five influential factors were fully studied. It is found that the total efficiency is improved by increasing cavity size, inner window thickness, emissivity of inner surfaces and distance between windows. Compared with SW-PVR, the DW-PVR gets a higher thermal efficiency at the expense of a lower optical efficiency. With a relatively large distance between windows and relatively small cavity size, the total efficiency of DW-PVR can be higher than that for SW-PVR. The peak temperature of the outer window in DW-PVR is 38.6–82.6 K lower than that in SW-PVR. The present work can provide a deeper understanding of characteristics of DW-PVRs.