Numerical Simulation Of Indoor Microbial Aerosols Propagation In Start-up Stage Of Air Conditioning

Due to the internal temperature and humidity conditions,central air conditioning system breeds microorganisms easily.In the air conditioning start-up phase,with the continuous air supply to the room,the residual air inside the dust carrying microbial aerosol particle will enter the room and affect human health.In response to this problem,this paper studies the propagation of microbial aerosol particle which entering the indoor space based on the way of particle movement and the specific data detected by predecessors.By analyzing the number of microbial aerosol particle which come into contact with people from different locations in the room,and comparing the distribution characteristics of the particle in different air flow forms,the paper provides a theoretical basis for further research to improve the indoor air quality of centric central air conditioning.Through the numerical simulation of the propagation of indoor microbial aerosol particle in the start-up phase of air conditioning,the main conclusions are as follows:(1)After 15 minutes of air conditioning running,the amount of suspended aerosol particle in the room is very small.At this time,the microbes carried by the particle from the duct have little effect on the human body.The change of microbial aerosol particle is consistent between 4 microns and 15 microns,while the 30 microns particle remained essentially unchanged after 5 minutes,and the main state is deposition on the ground.(2)In the comparison of three different sizes microbial aerosol particles,15 microns come into contact with people of the largest number each time period,thus the microorganisms carried by 15 microns aerosol particle is more harmful to the human body compared to the other two sizes particles.(3)Between the time at 20 second to 80 second of the air conditioning opening phase,people in the large concentration microbial aerosol particles.The maximum exposure of the three ways of simulating indoor aerosol particle contamination is at the 30 second time point,indicating that the indoor personnel in the high-density microbial aerosol particle environment at this time.If the particle carried high-risk bacteria,viruses,etc.at the time,the staff most likely to capture and infected.Due to purifier equipment participate in airflow organization by mechanical power,indoor microbial aerosol particle reduction speed is more quickly,so the maximum exposure of personnel completed to the other two cases is smaller.(4)In the three different forms of airflow,the staff who far away from the outlet capture the highest particle number compared to other locations in the air conditioning opening phase,while the staff in the middle of the room capture a least number of microbial aerosol particle throughout the process,and the staff at this location can be in a good air quality environment.In this paper,the microbial aerosol particle contaminants are simulated numerically in unsteady condition,and studied the distribution and diffusion characteristics in air conditioning room.By studying the distribution of microbial aerosols at different times and locations,it is helpful to remind the staff in the room to be far from the low air quality area avoiding excessively inhale harmful gases and damage the health.Through the analysis of different ways to remove indoor microbial aerosols contamination,this paper provides relevant operational basis for improving the indoor air quality in people's daily life.