适用于孔板送风的孔板阻力特性研究

Study on resistance characteristics of perforated plate suitable for perforated ceiling air supply

为了提高孔板送风房间流场预测的准确性,采用数值模拟结合试验验证的方法,以局部阻力系数为评价指标,分别对不同开孔形状、孔板厚度、孔口直径、开孔率的孔板的阻力特性展开了研究。结果表明:开孔形状对局部阻力系数影响较小,随着当量直径的增大,局部阻力系数略微增加,5种常见开孔形状下的平均局部阻力系数最大值与最小值偏差为4.5%;随着孔板厚度的增大,局部阻力系数减小,孔板厚度在1~3 mm范围内,平均局部阻力系数最大值与最小值偏差为17.8%;随着孔口直径的增大,局部阻力系数增加,直径在4~10 mm范围内,平均局部阻力系数最大值与最小值偏差为15.1%;随着开孔率的降低,局部阻力系数显著提高,且两者之间存在幂函数的变化关系。通过对数据进行分析,得到了适用于开孔率范围为0.01~0.05的孔板局部阻力系数近似计算式,该式为孔板送风房间流场预测提供了一定的数据基础。

In order to improve the accuracy of flow field prediction in air supply room with orifice plate,by taking the local resistance coefficient as the evaluation index,the resistance characteristics of perforated plates with different opening shape,perforated plate thickness,hole diameter and opening rate were studied by combining numerical simulation with experimental verification.The results show that the shape of the opening has little effect on the local resistance coefficient.With the increase of the equivalent diameter,the local resistance coefficient increases slightly.The deviation between the maximum value and the minimum value of the average local resistance coefficient under the five common opening shapes is 4.5%.With the increase of perforated plate thickness,the local resistance coefficient decreases.In the range of 1 to 3 mm,the deviation between the maximum and minimum average local resistance coefficient is 17.8%.With the increase of opening diameter,the local resistance coefficient increases.In the range of 4 to 10 mm,the deviation between the maximum and minimum average local resistance coefficient is 15.1%.With the decrease of the opening ratio,the local resistance coefficient increases significantly,and there is a power function relationship between them.By analyzing the data,an approximate formula for calculating the local resistance coefficient of the perforated plate is obtained,which is suitable for the range of 0.01 to 0.05 opening rate.This formula provides a certain data basis for the prediction of the flow field in the perforated plate air supply room.