태양 추적형 Evacuated CPC 집열기의 열성능에 대한 연구

초록

A numerical study was performed to investigate the effect of using a sun tracking system on the thermal performance of the evacuated compound parabolic concentrator (CPC) collectors. The evacuated CPC collectors consist of a two-layered glass tube, a copper tube and a reflector. The collector has a copper tube as an absorber, a reflector inside a glass tube. The water is used as a working fluid. The length and the diameter of the glass tube are 1,700㎜ and 70㎜, respectively. The length and the diameter of the copper tube are 1,700㎜ and 25.4㎜, respectively. Ray tracing analysis is carried out in order to compared with absorbed heat flux on the absorber surface of the stationary and tracking collectors. The collected energy is calculated and compared with that on a fixed surface tilted at 35° towards the south. The results indicate that the collected solar energy of the sun tracking system is significantly larger than that of a stationary collector. The sun tracking evacuated CPC collectors show a better performance with an increase in the thermal efficiency of up to 14% compared with an identical stationary collector.