入口高度和热流对太阳能热烟囱系统内流动换热的影响

EFFECT OF ENTRANCE HEIGHT AND HEAT FLUX ON FLOW AND HEAT TRANSFER IN SOLAR CHIMNEY

对从太阳能热烟囱系统抽象出的流动和换热模型进行了数值模拟。数值结果表明,随着底部加热热流密度的增加,系统内的空气流量增加;当集热棚高度变化时,流经系统的空气流量和系统出力存在最大值;在本文计算采用的几何和物理条件下,入口高度约为20m时系统的空气流量取得最大值;系统内部的压力差随着集热棚高度的增加而减小。

A numerical study has been carried out on the flow in a two-dimensional solar chimney with fixed heat flux on its bottom. The numerical results indicated that the mass flux is an increasing function of the heat flux at the bottom. The mass flux through the system and the output of the system each has a maximum as the entrance height of the collector varying. The entrance height is about 20 m when the mass flux reaches its maximum in calculated condition of this study. Driving force of the system is a decreasing function of the entrance height of the collector.