内置式PV-Trombe墙自然通风的数值研究

提出了一种新的内置式PV-Trombe墙模型,并通过CFD方法对自然通风进行了数值模拟。分析了太阳辐射和流道宽度对气流模式和通风量的影响。结果表明,太阳辐射、流道宽度和高度对通风量的影响非常明显。通风量随太阳辐射强度和高度的增加而增大。当流道宽度从0.1m增加到0.4m时,通风量呈单调递增趋势,然而当宽度增加到0.5m时,流道顶部区域的空气出现回流并且通风量开始减小。对于3m高的模型,最大通风量出现在流道宽度等于0.4m时。流道宽度是影响流道内空气自然对流的流动形态的主要因素,当流道宽度尺寸在0.1~0.4m之间时,流道内的空气为层流热分层流动。当宽度超过0.5m后,流道上部区域出现的回流使得热分层流动消失,空气从层流向湍流转变。

Numerical analysis of Natural Ventilation in Built-in Photovoltaic-Trombe Wall

The natural ventilation in a novel built-in photovoltaic-Trombe wall (BiPV-TW) was numerically simulated by CFD method. The effect of solar radiation, channel width and height on the air flow pattern and ventilation rate was analyzed. Results show that the solar radiation, channel width and height influenced the ventilation rate remarkably. As the solar radiation and BiPV-TW height increased,the ventilation rate increased. As the channel width increasing from 0.1 m to 0.4 m, the ventilation rate monotonously increased. However, when the channel width exceeded 0.5 m, the reverse flow was formed in the top zone and the ventilation rate decreased. A maximum air volume flow rate was achieved when the channel width was approximately equal to 0.4 m in a 3 m height model. The channel width was the dominant factor that influenced the flow pattern in the channel. When the channel width was smaller than 0.4 m, the airflow was thermally stratified laminar flow. When the channel width exceeded 0.5 m, thermally stratified flow disappeared due to the reverse flow formed in the top zone and the laminar flow became turbulent.