Compound Circular Reflector of a Novel Design for Evacuated Tubular Collectors

Abstract

A new type of the reflectors for evacuated tubular collectors (ETC) which we referred to as a Compound Circular Reflector (CCR) was designed. The reflectors allow reducing the number of tubes per collector area due to increasing the center-to-center distance of tubes, i.e. the pitch of tubes, so that the weight and cost of the collectors coupled with the reflectors decrease. The reflectors also improve collector efficiency. In comparison with a collector coupled with the planar reflectors, the collector coupled with CCRs accomplished following purposes: The weight per collector area decreases by 20% and the collector efficiency increases by about 7 percentage points as well as the cost of production per collector area decreases by 33%. Therefore the cost-effectiveness of the collectors is markedly improved.