| The occurrence of haze and other extreme weather can cause asthma,bronchitis and other respiratory diseases,causing serious harm and impact on people’s physical and mental health,so that people realize the importance of air quality for life and work.The composition of particulate matter in the air is more complex,the common indicators are PM10,PM2.5,PM1,these particles can cross action through a variety of ways,increase the degree of air pollution,and then affect the air quality of indoor environment.Filter materials in air purifiers can better purify fine particle pollutants and improve indoor air quality,so it is of practical significance to develop filter materials with excellent performance to solve particulate pollution.In this thesis,metal-organic skeleton material-textile cloth composite filter membrane（Zn/Co-MOF）was prepared by solution method,and its purification performance of PM10,PM2.5,PM1 in indoor air was studied.A numerical model was established to simulate the pressure field and velocity field under the influence of different inlet wind speeds.It provides theoretical reference for the development of new air filter material and air purifier.The main research contents are as follows:（1）At room temperature,bimetallic organic skeleton Zn/Co-MOF filter membrane was synthesized by solution method,and the mass ratio of zinc and cobalt metal was 1:3,and in the synthesis process of sodium carboxymethyl cellulose as a stabilizer,sodium carboxymethyl cellulose acts as the"molecular bridge"between fiber and crystal particles,so as to make the synthetic crystal skeleton stability is better.The morphology and crystal structure of the materials were characterized by SEM,XRD and BET.（2）Conduct an experimental study on particulate matter purification performance of Zn/Co-MOF filter material,and test the influence of wind speed,initial concentration and number of filter film layers on material purification performance.The results show that:A.The comparison test results of purification performance between fiber filter membrane and Zn/Co-MOF filter membrane show that the purification rate of particulate matter in air is69.6%by fiber filter membrane,and 97.2%by Zn/Co-MOF filter membrane.Zn/Co-MOF material has excellent adsorption performance.B.Zn/Co-MOF filter membrane purification test results show that the filtering efficiency of Zn/Co-MOF material for particles with different particle sizes is high.The filtering efficiency decreases with the increase of wind speed and increases with the increase of initial concentration of particles,and increases with the increase of thickness.When the wind speed is 1cm/s,the particle concentration is 120μg/m3 and the filter membrane is three layers,the purification efficiency of particulate matter is the highest,and the purification efficiency of PM1,PM2.5and PM10 are 97.2%,97.1%and 96.9%,respectively.When the number of membrane layers is three,the purification efficiency of particulate matter in the air is the highest.（3）Gambit software is used to establish the geometric model of air purification device and conduct mesh division.Porous media model is used to simulate filtration materials.Fluent software is used to conduct numerical simulation of flow field under different inlet wind speeds.The pressure field shows that the pressure increases gradually with the direction of fluid flow and reaches the maximum value in the porous medium region.After passing through the porous media region,the pressure plummets and then increases along the direction of fluid flow.And with the gradual increase of inlet wind speed,the change range of pressure gradient in the pipeline also increases,resulting in more chaotic air flow in the air duct.Look from the velocity field:speed is gradually increasing in the area before,in front of the porous medium in the area to peak,and began a downward trend,speed reduced to a minimum,through porous media in the region continue to increase gradually,and a peak at the exit,and due to the effect of resistance of the porous medium and export airflow superposition effect caused by eddy current phenomenon.The porous medium material in the middle area increases the filtration resistance,makes the airflow speed decrease suddenly,and the pressure also decreases to a certain extent,and there is a certain eddy current phenomenon in the front and rear areas.This is because the fine particles in the airflow here are absorbed and intercepted,which is consistent with the data of the actual purification experiment.The purification device reduces the concentration of fine particulate matter from 127μg/m3 to 3.6μg/m3,and the purification efficiency is as high as97.2%,indicating that the purification device has a good purification effect on particulate matter in the air. |
