蒸发式冷凝器在空气流动下优化设计数值模拟

Optimal simulation of evaporative condenser under the condition of air flow

利用FLUENT软件对3种常用的管形蒸发式冷凝器在空气流动状态下进行了优化设计的数值模拟,比较分析了在不同入口风速下的压降变化规律;对来流速度大小与来流角进行了优化设计,得到最适宜的来流速度在2.4—3.3 m/s,入口来流角θ范围为-15°—15°;在不同空气流量下管排的纵向间距与横向间距之比(S/L)模拟结果表明,在一定空气流量下,不同管形管排的S/L存在着一个最佳值,使得单位压降下换热盘管的平均表面传热系数最大,而且随着流量的增加,最佳的比值呈减小趋势。为蒸发式冷凝器的优化设计提供了重要依据。

Optimal design in evaporative condenser with three different tubes was numerically simulated by software FLUENT under the condition of air flow. The pressure drop rule of different inlet velocity was analyzed, the optimal direction of air inlet is from -15° to 15°, the optimal velocity value is from 2.4 to 3.3 m/s. It shows that there exists an optimal value for the ratio of lengthways tube space to transverse tube space, and this optimal value decreases with the increase of air flow rate. The conclusions are useful for the design of evaporative condenser.