Radiation performance of a cavity receiver for a parabolic dish solar concentrator system

Abstract

Abstract. The radiation performance of a modified cavity receiver for a low-cost concentrating solar power plant is studied. The optical phenomenon taking place is modelled by using a ray tracing technique based on a finite element approach. This design is also compared to a flat receiver. Corrections for sunlight and optical errors of the parabolic dish are included. Its efficiency is analysed by varying some geometrical parameters of the receiver, maximizing the total power absorbed. It is found that the flux density on the cavity walls is less than on the flat receiver walls, hence decreasing heat losses. Also, in order to reach a maximum radiation performance the receiver is to be placed closer to the concentrator from the focal position. However, the aperture does not improve notably its efficiency, although it has an important role in the convection heat losses as shown in previous works. Finally by varying the cavity diameter it is possible to improve the efficiency when it is well adjusted to the radiation performance of the concentrator on the focal point.

Convective Heat Loss Analysis of a Cavity Receiver for a Solar Concentrator

“…Cavity receivers are usually developed with the aim to reduce convective and radiation thermal losses. This paper extends the work in [6]. The purpose is to analyse the convective heat loss from two different receiver types under different operating conditions of wind and inclination.…”

“…This flux is obtained from [6]. In the following the assumptions used for constructing the temperature field are detailed for every receiver.…”