Analyze of thermal performance and thermal stress and distribution on inverted solar cavity receiver

Abstract

Concentrated solar thermal is a beneficial tool to generate high quality heat and power with high efficiency. Air cavity receivers are used for achieve high temperature in solar applications. Conical inverted cavity receiver was studied numerically. Working fluid was considered air with laminar flow characteristics. Outer surface was subjected to constant heat flux and inner surface was insulated. The numerical model was validated with numerical and experimental data present in the literature. At the optical view point inverted cavity was compared with normal position one, inverted conical cavity receiver was beneficial. The proportion of used radiation from the receiver, which outer surface is expose to sunlight, is significantly higher than normal conical cavity. Inverted conical cavity receiver has 7.46% higher Nusselt number performs at the Reynolds number of 500. On the other hand, Nu has increased 28.89% when the Reynolds number was 2100. The centrifugal forces more influential at the outer surface, the speed of flow at the outer surface is 2 to 3 times higher than that for the inner surface. Heat distribution in inverted conical cavity receiver is significantly more uniform than conical cavity receiver with normal orientation.