三角形小翼强化立式太阳能热气流电站的流动传热特性

Triangular winglet strengthen heat transfer characteristics of solar chimney power plants with vertical collectors

采用数值计算方法研究设置在电站系统中空气流道内集热面上的三角形小翼对立式太阳能热气流发电系统非稳态自然对流流动及传热的强化作用,分析了肋对数、肋倾角、布置方式对系统进出口气流的温升、速度差的影响,并结合场协同原理对其强化太阳能热发电系统传热的效果进行评价。结果表明:空气流经三角形小翼时温度梯度增大,换热增强,系统进出口气流温度差、速度差大幅增大;随着肋对数的增加,气流受到的扰动作用增强,速度与温度梯度的协同角减小,但相应也使气流的流动阻力增大,能量损失增大,肋倾角取45°时系统进出口气流速度差最大;三角形小翼成对布置在竖直矩形通道内时,叉排布置效果优于顺排。

In this paper,triangular winglets strengthening the unsteady natural convection flow and heat transfer,which were set up on the collector surface in the solar chimney power plant system,was researched with numerical methods.The number of ribs,rib inclination and arrangement influence on the temperature and velocity difference of the airflow between the inlet and outlet were analyzed.And heat effects of the triangular winglets were evaluated combining with the principle of field synergy.The results show that:With air flowed through the triangular winglets,the temperature gradient increases,the heat transfer is enhanced,the temperature and velocity difference of the airflow between the inlet and outlet increases sharply.As the number of ribs increased,the synergy angle between velocity and temperature gradient decreased because the disturbed effect enhanced,but energy loss increased as the flow friction increased,and when rib inclination is 45°,the velocity difference between inlet and outlet is the largest.With triangular winglets arranged in the vertical rectangular channel,staggered arrangement is better than the aligned.