风量罩罩体对通风系统产生的阻力影响及基于CFD模拟的阻力分析

Impact of Air Volume Hood on Ventilation System Resistance and Resistance Analysis Based on CFD

目前风量罩广泛应用于暖通空调行业,但在测量过程中存在测量结果不准确的问题。文章通过实验发现,在实际测量过程中风量罩罩体会对通风系统产生静压影响,阻碍系统出风。同时发现在风量较小、安装孔径较小的孔板时,在风洞出口处罩上风量罩前后风量的大小并没有发生多大改变;而在风量较大、采用孔径较大的孔板后,安装风量罩前后风量大小发生了很大的改变。因此,基于CFD模拟分析可得出结论:当风量较小、采用较小孔径孔板对管道内流体产生的阻力远大于风量罩对管道内流体产生的阻力,此时风量罩影响较小;但是,当风量较大、采用较大孔板对管道内流体产生的阻力与风量罩对管道内流体产生的阻力近似相等时,风量罩对风洞系统出风量产生的影响是不可忽略的,需要修正及解决。

The air volume hood is widely used in the air volume HVAC industry,but there is a problem of inaccurate measurement results during the measurement process.It was found through experiments that during the actual measurement process,the air volume hood will affect the static pressure of the ventilation system and hinder the air from the system.At the same time,it was found that when the orifice with a small air volume and a small aperture was installed,the air volume before and after the air volume cover was covered at the wind tunnel exit did not change much.However,when the air volume is large and the orifice plate with a large aperture is used,the air volume before and after the air volume cover is installed has changed greatly.Further,based on the CFD,it is concluded that when the air volume is small and the orifice with a smaller aperture produces a much greater resistance to the fluid in the pipe than the air volume hood's resistance to the fluid in the pipe,the air volume hood has a smaller impact.However,when the air volume is large,the resistance generated by the larger orifice plate to the fluid in the pipeline is approximately equal to the resistance generated by the air volume cover to the fluid in the pipeline.At this time,the influence of the air volume hood on the air volume of the wind tunnel system cannot be ignored and needs to be corrected and resolved.