A Review of Linear Fresnel Collector Receivers used in Solar Thermal Technology

Abstract

Linear Fresnel collectors (LFC) have, among the four technologies of concentrating solar power (CSP), the simpler technology. They have a one axis sun tracking, plane mirrors and a fix receiver. All these elements make them the most suitable for small scales CSP plants adapted to rural area of the Sub-Saharan region. The receiver is an important part of the LFC. There is a wide variety of receivers that differ in the shape of the absorber: mono-tube, multi-tube, plane. The shape of the secondary concentrator or its absence allows to categorize the receivers in a butterfly, compound parabolic concentrator, segmented parabolic secondary concentrator or trapezoidal receiver. Vacuum mono-tube receivers have heat losses between 200 W/m and 270 W/m at an absorber temperature of 350°C. A mono tube receiver at partial vacuum losses more than 350 W/m at 350°C. The lowest heat losses of a multi-tube receiver with a trapezoidal secondary concentrator can reach 500 W/m at an absorber temperature of 350°C. This paper discusses a comparative study of existing receiver designs in order to find the most suitable for rural areas in the sub-Saharan region, i.e. easy to design by hand and low cost. Although they do not have the best thermal performance, trapezoidal receivers with a black-painted copper multi-tube absorber and a glass cover seem to be the most suitable.