Simulation And Experimental Research On Multiphase Flow In Mini Air Purifier

With the smog weather frequently happened,air pollution has attracted much attention,the sales of air purification products are increasing year by year,but in the market,the quality of products is uneven,there are still many problems.This paper focuses on ultra-fine and sub-micron particles to explore the multiphase flow in the mini air purifier.The main research contents are as follows:(1)The experimental results show that the purifier had the lowest filtration efficiency for 32 nm particles,the number of 100 nm particles accounted for the highest proportion before and after filtration,adding negative ion generators inside the purifier had a good complementary effect on the particle size,besides,the boundary conditions,single filtration efficiency and negative ion dust removal efficiency of the air purifier were measured by the experimental instrument,which provided input parameters and reference parameters for the following simulation experiments.(2)Simulation experiment of multiphase flow in the purifier,modeled and preprocessed the calculation domain according to the structure of the purifier,input the collected experimental data into Fluent for simulation experiment,it is found that the eddy current in the purifier makes the collision rate between particles and the inner wall up to 39%;the bias of the fan makes the inlet velocity unevenly distributed in the vertical direction,which leads to the uneven loss of the filter core,and causes the particles deposit at the bottom and the particles near the outlet trapping difficultly.(3)Optimum design of mini air purifier,pay attention to the purifying efficiency,wind resistance,cost,safety and operability of the purifier,through numerical simulation technology to achieve the simulation experiment of electrostatic precipitation and adding inner uncovered cylindrical filter paper,it is found that adding an electric field inside the purifier can effectively improve the efficiency of negative ion purification,but the marginal utility of increasing the voltage decreases with the increase of the voltage,adding a cylindrical cover-less filter paper inside the purifier costs low and operates conveniently,it can effectivelyimprove the collection efficiency and alleviate the problem of uneven inlet velocity,the resulting wind resistance is less than 1% at low wind speed and less than 7% at high wind speed,and it decreases with the increase of the thickness of filter paper,the overall scheme has the best effct when the thickness of filter paper is 3 mm.