有风环境下太阳能吸热器混合对流热损失特性

Combined Convection Heat Loss Characteristics of Solar Receiver Under Windy Environment

采用三维数值模拟方法研究了太阳能吸热器在有风环境下的混合对流热损失特性,得到了吸热器腔体内部的温度分布和采光口截面的速度分布以及对流热损失大小与倾角、风向的关系曲线。结果表明,与无风环境下太阳能吸热器对流热损失随倾角增加而单调减小的规律不同,有风环境下,太阳能吸热器混合对流热损失同时受到环境风和倾角的共同影响,且规律较为复杂。当风向背对采光口时,吸热器混合对流热损失在不同倾角下随风向的变化较小,但当风向正对采光口时,吸热器混合对流热损失随风向的变化较为剧烈,受到倾角的影响也较为显著。

A three-dimensional numerical simulation has been carried out to capture the combined convection heat loss characteristics of solar receiver under windy environment. Temperature contours inside the cavity, velocity contours on the aperture plane, and the variation of combined convection heat loss versus wind direction and tilt angle have been obtained. Different from the discipline that the convection heat loss decreases monotonically with the increasing of tilt angle under no-wind environment, the combined convection heat loss of solar receiver in windy environment is affected by both the wind and the tilt angle, and is more complex. When the wind flows toward the back of receiver, the combined convection heat loss varies little with the wind direction for the receiver at different tilt angles, but when the wind flows toward the aperture of receiver, the combined convection heat loss changes dramatically with the wind direction, and the tilt angle shows more significant impact on it.