Analysis Of Personnel Safe Distance For The Transmission Of Droplet Pollutants

At the beginning of 2020,the novel coronavirus pneumonia spread all over the world has become one of the major security issues of concern to the world.According to a large number of clinical data and research data accumulated by scientists,these viruses,like ordinary viruses,are widely spread among people through droplets,contact,air and other means.The essential.Therefore,it is very necessary to study the influence of droplet pollutant transmission and its movement trajectory.This paper takes the air-conditioned room as the research object,compares various turbulence models,uses the ANSYS Fluent simulation software to simulate,and selects the RNG k-ε model as the turbulence model in this paper to simulate the velocity field and temperature field of the indoor airflow organization.Mathematical model of droplet pollutant movement was established using Eulerian-Lagrange method.Two situations are mainly considered: in the case of a single person,the influence of air supply mode and body posture on the transmission distance of droplet pollutants;in the case of two people,different standing positions,different distances,and different particle sizes of droplets affect the transmission of droplet pollutants.effect of distance.The simulation results under different working conditions were compared and analyzed by using the droplet pollutant concentration curves of each typical section,the number of droplet pollutants inhaled by healthy persons and the pollutant movement trajectory.By comparing the simulation results of different working conditions,it is shown that in the case of a single person,the movement trajectory and distribution of droplet aerosol particles are different with different air supply methods.Under the air supply mode,the droplets are distributed chaotically and spread all over the room.The top delivery and the lower back propagation distance are the farthest,but the head of the human body is strongly blown by the air supply port,which does not satisfy the comfort of the human body.The transmission safety distance of upper and lower return and replacement ventilation is similar,and the concentration is minimized at 1.2m in front of the human body.In the case of two people: increasing the air supply speed can reduce the residence time and movement distance of droplet aerosols in the room.Different standing positions of people,that is,the direction of the initial velocity of droplet aerosol particles and the form of airflow organization affect the movement trajectory of droplets and thus the concentration of pollutants near the infected person.Different particle size affects the height of droplets rising in the vertical direction and the advancing distance in the horizontal direction.When the distance between the two people is 0.5m and 1m,the healthy person is completely exposed to the polluted area;when the distance between the two people is between 1.0m and 1.5m,the amount of pollutants inhaled by the healthy person decreases with the increase of the distance between the two people.When the distance between the two people is more than 1.5m,the effect of the distance between the two people on the droplet trajectory is no longer important and has little significance.Therefore,in areas with high density of people,it is necessary to increase the air supply to control the spread of pollutants.In the low-density space area,keep a distance of1.5m between people as much as possible.