Energy Flux Distribution and Thermal Performance of Linear Fresnel Collector System in Cold Region

摘要

In this paper, on the base of principle of linear Fresnel reflective collector, a three-dimensional framework of linear Fresnel reflector field (LFR), compound parabolic collector (CPC) and the absorber tube with selective absorption coating and glass tube were established, together with calculating optical efficiency of the vacuum tube collector at different incident angles of the linear Fresnel system in the cold region. As revealed by the findings, the angle of light was in the range of 0 style="font-family:Verdana;">° style="font-family:Verdana;">- 60 style="font-family:Verdana;">° style="font-family:Verdana;">, and the optical efficiency amounted to be the lowest at the incident angle of 15°. When the incident angle was 75 style="font-family:Verdana;">° style="font-family:Verdana;">, the optical efficiency displayed an obvious reduction, and as the incident angle was 0 style="font-family:Verdana;">° style="font-family:Verdana;">, the distribution of the energy flow in the tube was more standardized. Because of the incidence of the end loss, some tube length is unable to flow in the direction. For the purpose of performing the experiment the thermal performance of linear Fresnel system in the cold region, introduction of the thermal transfer factor was made, together with the analysis of the measured data under the condition of no loss of the receiver. The maximum theoretical efficiency of the system amounted to 68%, and the optical loss was approximately the total solar radiation at 32%.