置换通风与冷却顶板空调系统CFD分析

Analysis of Displacement Ventilation and CFD in Air Condition System for Cooling Ceiling

冷却顶板只能除去显热负荷,无法除去湿负荷,置换通风的除湿能力受到送风量的限制,当整个制冷系统处于温度最低点时,冷却顶板表面温度可能会降到室内空气露点温度以下,而出现结露的危险。为了保证冷却顶板表面不结露特别是在湿负荷较高的状况下,作者提出了在冷却顶板表面形成干燥空气保护层的方案,同时以计算流体力学(CFD)的模型为基础,采用有限容积法对具有干燥空气保护层的冷却吊顶—置换通风系统的气流分布进行了模拟分析,表明该方案可以有效削减垂直温度梯度,提高舒适性,解决结露问题。

As the chilled beams can remove the heat,but the moisture and the removing humidity capability of the displacement ventilation is limited by the inlet air ventilation rate.When the temperature of the system working condition comes to the lowest point,the exterior temperature of the cooled surface may be lower than the dew point of the indoor air and the moisture will condense on the cooled surface.To avoid condensation on the cooled surface,in this paper the authors simulate and analyze the velocity distribution of the cooled ceiling and displacement ventilation air condition system with a dry air layer close to the cooled surface using the finite volume method based on the method of computational fluid dynamics(CFD),and draw the concludes that the approach can cut down the temperature difference and elevate the comfort,and therein the problem of appearing dew is settled as well.