| With the changing of people's life,people pay more attention to the indoor air quality and the need is higher.So the nation has come on a series of related standard to ensure the air quality in public places.The average value per day of particles in the indoor air should be equal to or less than 0.15mg/m3.The PM10 in output t of central air conditioning system should be equal to or less than 0.08mg/m3。It's the most valid way to use filter filtrate the indoor particles pollutant from outside.In the time,the maintenance and cleaning expenses are cut down.But there is no clearly node or comparable data of how to choose the air conditioning system's filter in the public building.According to the data of the provinces and the cities of our country,it shows the filter efficiency is low,the density of the pollutant indoor could not reach the standard and the result is that the person indoor feel uncomfortable,the work efficiency is low leading to economic loss.The issue is about the analysis of the particles' density and size distribution of goose pagoda road of beilin district in Xi'an from October 2007 to September 2008. During the measure of 12 months,the value of PMio range from 0.119 to 0.408mg/m3, the day average value is 0.237 mg/m3,higher than the national code second class 158%, the air quality is low degree pollution.According to the particles' density and size distribution this area,there is a suggestion of how to choose and design the filter in the air conditioning system:the new input filter should attain the level of G3(80%-90%); In consideration of the efficiency of two class filters closely should not differ too much, or else the ex-filter couldn't protect the next one,so the first filter in the mixing section should attain the level of F5(40%-60%),the second filter should attain the level of F6(60%-80%).Simulate three kinds of the fresh air and return air distribution mode using the software Fluent,Analysis the air flow distribution before the filter which is the important factor that influence the efficiency of filter.It's found that when the return air from the sideway,the velocity of the mixed air distribute average.This mode is better.It is the most valid method of controlling the indoor particle to use the filter.But the domestic public building suffer the second pollution caused by the air conditioning system,the problem of the unqualified installation and the lower efficiency of filter is widely happened.The issue aim at the design and choose of filter while in the atmosphere of Xi'an city. |
