为了深入分析通道直径的影响,不同通道直径的速度矢量如图所示。可以发现,在入口质量流量恒定的情况下,通道直径越小,流体速度越快,越容易形成湍流,传热能力越强,努塞尔特数越大。然而,流速越高,通道压降越大。因此,在选择合适的 PCHE 通道直径时,应考虑热交换能力和压力损失。
To in-depth analyze the influence of channel diameter, the velocity vectors of the various channel diameters are shown in Figure. One can find that for a constant inlet mass flow rate, the smaller the channel diameter, the faster the fluid velocity, the easier it is to form turbulent flow, the stronger the heat transfer capacity, and the larger the Nusselt number. However, a higher flow rate would result in a greater channel pressure drop. Therefore, heat exchange ability and pressure loss should be considered when selecting the suitable channel diameter for a PCHE.