Experimental Study On PM_2.5 Purification Characteristics Of Low Resistance And High Efficiency Filter Units In Building Healthy Environments

At this stage,China’s air pollution is gradually transitioning from total suspended particulate（TSP）,PM₁₀and SO₂pollution to composite air pollution formed by PM_2.5,O₃and NO₂.Since the end of 2011,many large-scale smog incidents across the country have attracted widespread attention at home and abroad.The concept of PM_2.5has been widely accepted by the public.Taking Hefei City as a key city,according to the relevant data released by the China Environmental Monitoring Station,the survey,statistics and evaluation of the environmental quality from 2015 to 2021 are carried out.The results showed that from 2015 to 2021,the annual average concentration of PM_2.5in Hefei decreased year by year,and the annual average concentration of PM_2.5dropped below 35μg/m3for the first time in 2020.In 2021,the annual average mass concentration of PM_2.5decreased by 12.28%year on year,and the level of fine particulate matter pollution in Hefei was controlled to some extent.In view of the problem of indoor purification in buildings in the post-epidemic era,an air cleaner that can replace various filter units is designed.11 kinds of different filter units were selected and divided into two groups:coarse-medium efficiency and high-medium efficiency and above.The PM_2.5purification performance of different filter units was analyzed through experiments（No.1 is G4clip carbon cloth filter unit,No.2 is G4 polyester filter unit,No.3 is F7 glass fiber filter unit,No.4 is F7 electrostatic meltblown cloth filter unit,No.5 is G4polyester+F7 glass fiber filter unit,No.6 is micro-electrostatic charge module+G4polyester filter unit）.The experiment tested the primary filtration efficiency,PM_2.5purification efficiency,resistance,clean air delivery volume（CADR）,cleaning energy efficiency（CEE）and applying space of different filter units.The second group of test materials is from No.7 to No.11(No.7 is high-medium efficiency glass fiber filter unit,No.8 is sub-high efficiency filter paper filter unit,No.9 is electrostatic structure precipitators（ESP）,No.10 is intense field dielectric（IFD）,No.11 is high-efficiency polymer tetra fluoroethylene（PTFE）filter unit and increased ozone concentration compared to the first set of tests.The results show that the gradient combination of G4 polyester+F7 glass fiber filter unit and the combination of micro-electrostatic charge module+G4 polyester filter unit can effectively improve the primary filtration efficiency and PM_2.5purification efficiency.Under the rated wind speed,the No.2 filter unit has the smallest resistance,the No.6 filter unit has the same resistance as the No.2 filter unit,and the No.5 filter unit has the largest resistance.Under the condition of maximum air volume,the CADR and CEE of No.2 filter unit are the smallest,and the CADR and CEE of No.4 filter unit are the largest.The CADR and CEE of No.2 filter unit were about 7.13%and 6.54%of that of No.4 filter unit,respectively.Compared with the No.2 filter unit,the CADR and CEE of the No.6 filter unit are increased by about150%and 247%,respectively.High-medium efficiency and above filter units can purify PM_2.5more effectively.The filtration efficiency of ESP and IFD is close to that of sub-high efficiency filter paper filter units and decreases with the increase of wind speed,while the filtration efficiency of fiber filter units efficiency is the opposite.Although cleaners with different filter units can quickly purify fine particles,the CADR and CEE of the IFD are the largest and the CADR and CEE of the high-medium efficiency glass fiber purifier are the smallest.Moreover,the CADR and CEE of the high-medium efficiency glass fiber purifier are about 48.34%and 51.43%of the IFD,respectively.This topic focuses on the air filter unit for purifying PM_2.5,studies the related technologies of filtration and purification of fine particulate matter in indoor closed environment,and provides basic data support for the research of low-resistance and high-efficiency filter unit.Figure[35]table[18]reference[134]...