HEPA过滤器箱体内气流均匀性影响因素研究

Study on Influencing Factors of Air Flow Uniformity in HEPA Filter Housing

HEPA过滤器作为核电厂空气净化用的重要设备,内部气流均匀性将直接影响其使用寿命,进而影响空气净化效率。本文利用数值模拟的方法对HEPA过滤器内部气流流场进行模拟分析,对滤芯部分采用符合Darcy定理的多孔介质模型。在此基础上,通过改变过滤器模型上下壁面的倾斜角度、改变入口截面积,对过滤器的结构型式和入口风速进行敏感性分析。数值模拟结果表明,过滤器上下壁面的倾斜角度对过滤器内部气流均匀性的影响较小。入口风速对内部气流均匀性的影响较大,入口风速越小,过滤器内部均匀性越好。模拟分析结果表明,入口风速控制在10 m/s左右对于兼顾气流均匀性和设备尺寸有较好的效果。

The HEPA filter is an important equipment for air purification in nuclear power plant.The internal air flow uniformity will directly affect its service life,and thus affect the air purification efficiency.In this paper,the flow field in the HEPA filter is simulated and analyzed by numerical simulation,and the porous medium model in accordance with Darcy's theory is adopted for the filter element.On this basis,by changing the inclination angle of the upper and lower walls of the filter housing and changing the inlet cross-sectional area,the sensitivity of the filter structure and inlet wind speed is analyzed.The numerical simulation results show that the inclination angle of the upper and lower walls of the filter has little effect on the air flow uniformity in the filter.The inlet airflow velocity has a great impact on the internal air flow uniformity.The smaller the inlet airflow velocity is,the better the internal uniformity of the filter is.The simulation results show that controlling the inlet airflow velocity at about l0m/s has a good effect on considering the air flow uniformity and equipment size.