漏斗状储热水箱边界斜度对热量损失的影响

The effect of boundary slope of funnel-shaped heat storage tank on heat loss

为了研究太阳能跨季节蓄热过程中,漏斗状储热水箱的侧壁倾角对其内部自然对流换热情况的影响,文章采用Fluent软件对漏斗状储热水箱内非稳态自然对流换热情况进行了三维数值模拟。模拟结果表明:水箱侧壁倾角对漏斗状储热水箱内部的自然对流换热过程有一定的阻碍作用,水箱侧壁倾角θ越小,阻碍能力越大,但对流换热过程与水箱侧壁倾角之间并没有呈现出线性递增关系,此外,存在使壁面平均Nu数达到峰值点的水箱侧壁倾角;比表面积对漏斗状储热水箱的散热量有一定的影响,比表面积越大,漏斗状储热水箱的散热量越大;当水箱侧壁倾角θ为45°时,漏斗状储热水箱的储热效果最佳。

Aiming to the problem of the trans-seasonal solar heat storage, the heat transfer of the funnel-shaped heat storage tank is numerically studied especially for the effect of the wall slope of the tank. The Fluent software was used to conduct the three-dimensional simulation for the unsteady natural convection heat transfer in the funnel-shaped tank. The numerical results have revealed that there is a close relationship between the all angle θ and the heat transfer of the tank, while there is not a linear relationship between them. As the θ is equal to some value, the average Nusselt number on the tank wall reaches the maximum, and then declines gradually. On the other hand, it has identified that the specific surface area of the tank also affects the heat loss.The higher specific surface area promotes the heat loss of the tank. In generally, the tank of θ=45 °gave the best thermal performance in terms of the trans-seasonal solar energy storage.