Numerical Study of Natural Convection Heat Loss of Heat Pipe Receiver for Dish/Stirling System

Abstract

The receiver of dish/Stirling solar thermal power system is a critical component which must absorb incoming concentrated solar energy and deliver thermal power to the engine working fluid at high-flux from 40 to 80 W/cm2 and temperatures of 650–850°C. The heat loss of the receiver has serious influence upon the system performance. In this paper, a numerical study on the major convection heat loss from a heat pipe receiver of dish/stirling system is presented. The influence of the operating temperature, the inclination angle and aperture size on the total heat loss from the receiver was investigated. The effect of the temperature varying from 650 to 850 on heat loss of the receiver was simulated. The inclination angle ranges between 0° and 90° to estimate the influence of inclination upon convection heat loss of the heat pipe receiver. The receiver aperture is always optimized to be just large enough to admit most of the concentrated sunlight, but small enough to limit radiation and convection heat loss. The effect of aperture diameter to the heat loss is also investigated. The results indicate that the natural convection heat loss is decrease monotonically with the increase of the inclination angle; the aperture diameter is a critical parameter in design of a solar receiver. The investigation conclusions can be used as reference information for the heat pipe receiver design and application.