Analysis Of The Influence Of Human Movement On The Airflow Field And Particle Distribution In Kitchen

Creating a healthy and comfortable living environment is an effective way to improve people’s quality of life and achieve"Healthy China".As the heart of a house,the kitchen is worthy of attention to its environmental quality.There is a strong correlation between the kitchen environment and the air quality in residential buildings.The cooking methods of Chinese food are mostly frying,frying,cooking,and frying,and the amount of soot particulate matter produced accounts for about 7%of the total indoor particle mass in residential buildings and 10%to 30%of the organic aerosol mass.The oil fume particles produced by cooking are mostly fine particles and ultra-fine particles,which are easy to adhere to a large number of viruses,bacteria and organic substances.They have strong toxicological properties and increase the risk of kitchen operators suffering from cardiovascular and cerebrovascular diseases,bronchitis,asthma,lung cancer,and other related respiratory diseases.In the context of the construction of a healthy China,the problem of air pollution in the kitchens of residential buildings needs to be solved urgently.This thesis mainly studies the theoretical analysis,numerical simulation and dimensional solution of the airflow field and particle distribution in the kitchen environment when people are walking.Through in-depth study of the residence time of particulate matter in indoor space,its own diffusion,migration,and distribution characteristics,the principle of cooking oil fume particulate matter generation in the kitchen is summarized;Based on the law of mass conservation,the diffusion and transport characteristics and force equations of kitchen oil fume particles were analyzed,and the moving mesh model was used to establish a Chinese cooking kitchen model with people walking.In order to reduce the computational cost and time,the computational domain is divided into dynamic grid area and static grid area;Analyze the common two-phase flow model for simulating indoor particle transport,and determine to use the RNGΚ-εmodel and the Lagrangian discrete model to simulate and analyze the airflow field and particle distribution in the kitchen respectively;Change the human factors and objective factors in the movement of people respectively,and simulate the changes of the kitchen airflow organization and the distribution of soot particles under different working conditions;The influence of personnel movement on the air flow field and particle distribution in the kitchen environment is further expressed,and the dimensionless analysis method is introduced to determine the dimensionless of relevant influencing factors.Through multiple linear regression analysis,the influence of personnel movement on the air flow field and particle distribution in the kitchen space can be visually displayed.The results show that the movement of people causes lateral airflow near the cooking table,and the velocity field of the kitchen has obvious velocity changes and disturbances.The disturbance area continues to expand with the movement of people,and changes with the change of the movement direction of the people.Lateral airflow will cause the fume diffusion under the hood of the range hood to be offset,making it difficult to control the fume.The faster the people move,the more obvious the disturbance of the airflow field,and the more unfavorable for the capture of soot particulate matter;The turbulent airflow caused by the movement of people has basically the same effect on the two particle sizes of PM₁and PM_2.5,and the impact of the two particle sizes is less than that of PM₁₀.Changes in other human factors and objective factors have an impact on the airflow field and particle distribution.For example,changes in personnel height affect the airflow field in the kitchen space,but are not factors that affect the capture rate of particulate matter;The change of the distance between the personnel and the cooking table has different effects on the change of the airflow in the kitchen,which is unfavorable for the discharge of soot particles.The closer the distance,the greater the impact;During the movement of people,the larger the exhaust air volume of the range hood,the more obvious the change of the air distribution in the kitchen;the change of the cooking source speed only has a significant effect on the flow field near the range hood exhaust hood.Finally,combining the above simulation data with the dimensionless factor formula,three dimensionless physical formulas are obtained,which quantify the effect of each influencing factor.The research results of this thesis provide technical support for solving the problem of kitchen air pollution and ensuring the health of personnel.