Preliminary investigation on photo-thermal performance of a novel embedded building integrated solar evacuated tube collector with compound parabolic concentrator

摘要

An embedded building integrated solar evacuated tube collector (EBIETC) with compound parabolic concentrator (CPC) is designed, which is applied to buildings to alleviate the problem of insufficient heat water supply. The surface structure of embedded building integrated CPC (EBICPC) is developed, which could capture solar radiation for at least 6h a day throughout the year based on altitude angle of solstices. The optical simulation of EBIETC is carried out under variation projection altitude angles. Its optical efficiency is evaluated by the method of mathematical fitting and the simulation results show that the peak of optical efficiency for beam radiation could reach at 72.2%, and the average optical efficiency is about 64.5% within the range of optimal projection altitude angle. Furthermore, the heat transfer model of EBIETC is built and its reliability is verified via an integrated photo-thermal experiment that the relative error between the experimental value and theoretical value is between -8.6% and 10.8%. The experimental results show that the maximum instantaneous thermal efficiency and average thermal efficiency of the EBIETC are 55.4% and 51.4% respectively. The meaningful research results could provide a certain technology reference for the photo-thermal design of solar collector in buildings.