Research On The Effect Of Air Conditioning And Ventilation In Isolation Wards Under The Epidemic Of COVID-19

The outbreak of the COVID-19 epidemic has caused an unprecedented impact and influence on the life safety of our people.Although the COVID-19 epidemic has been effectively controlled with the joint efforts of medical staff and all sectors of society in China,in order to prevent the COVID-19 epidemic spreading again,the optimization and improvement of the air conditioning and ventilation performance of infectious isolation wards is a problem worthy of study.It is necessary to comprehensively consider all aspects of the air-conditioning and ventilation design of infectious isolation wards to improve ventilation efficiency and optimize isolation effects,reduce indoor pollutant concentrations and prevent secondary pollution caused by virus spread.For infectious isolation wards,several requirements need to be met when designing indoor air conditioning and ventilation design:strengthening the purification effect of pollutants in the air,reducing the probability of infection of medical staff,providing a comfortable living environment for patients with infectious diseases,avoiding the formation of eddy currents or The dead ends of ventilation lead to insufficient ventilation,environmental protection requirements for energy saving.Based on these principles,the author discussed the design points of the simplified version of the isolation ward,and finally came to a conclusion,and analyzed the key points and measures of the air-conditioning and ventilation design of the infectious isolation ward.The following points should be paid attention to in the air-conditioning design of infectious isolation wards: infectious isolation wards need to meet good isolation measures to prevent viruses from escaping from the room,and need to maintain indoor and outdoor pressure gradients to meet indoor negative pressure.At the same time,if the conditions are met,a buffer room needs to be set up to reduce the probability of the virus being taken out of the room.It is necessary to improve the airflow organization of air conditioning and ventilation,increase the number of indoor ventilation,and consider the design of local exhaust in key parts to fully dilute the concentration of indoor pollutants,especially to ensure that the concentration of pollutants in the working area of medical staff is low enough to reduce the number of medical staff.Risk of infection at work.In this paper,Gambit software is used to establish a simple version of the isolation ward model,and the location of air-conditioning air supply and exhaust vents in infectious isolation wards is discussed.The influence of the change in the size of the return air outlet on the distribution of indoor pollutants,comparing the indoor ventilation conditions when the air supply and exhaust outlets of the wards are located at different positions in each scheme,and analyzing the pollutants in the working area of medical staff under various schemes Concentration,temperature,and wind speed influence,and through comparison,a better ventilation plan for infectious isolation wards is obtained.At the same time,this paper also analyzes the COVID-19 epidemic infection model summed up by Professor Jiang Yi from Tsinghua University.According to the simple version of the ward model built in this paper,by analyzing the ward situation and setting more appropriate parameters,the fresh air volume required by the ward is calculated.,and then compared with the fresh air volume scheme used in the Fluent simulation to obtain the appropriate parameters of the COVID-19 epidemic infection model in a small infectious isolation ward.Under this model,when the parameter A(The probability of being infected after receiving the virus: Because the human system is between 0 and 1,it reflects the body’s resistance to the virus.The stronger the immunity,the smaller it will be)is set to 0.015 and B(It reflects the spatial characteristics of the public area and the density of people.The more closed the space,the more concentrated the activities of the people,and the more frequent the gathering of people,the smaller it will be)is set to 0.01,it can The equivalent dilution factor of indoor pollutants is calculated to be K=1424.6,the per capita fresh air volume is142.56m~3/h,the number of air changes is 17.66 times/hour,and the air velocity of the air outlet is 0.37m/s,which can better deal with indoor pollutants and Ensure that the wind speed in the room and the patient’s face is suitable,meet certain comfort requirements,and provide certain data support for the reconstruction of hospital wards in the future.