Study On Indoor Air Quality Evaluation And Ventilation Improvement Of Gymnasium

Life lies in exercise,and good living habits are the premise of health.As more and more people go to the gym,it becomes very important to exercise in a clean environment.Because the gym has a large flow of people every day and the air in the room is not circulating,the indoor air quality problem is becoming more and more serious.Based on this situation,the author selects a gym in Shenyang.Through subjective and objective investigation and research,as well as the application of grey system theory,this thesis adopts the method of numerical simulation to analyze the indoor air quality of the gym,and puts forward the ventilation optimization measures to improve the indoor air environment of the gym.Firstly,the data test of indoor air parameters(Temperature,Humidity,Wind speed,Formaldehyde,VOC,CO₂,PM_2.5)and subjective questionnaire survey of indoor personnel were carried out in this gym in winter,transition season and summer.The field test data show that the temperature and humidity in the gym basically meet the standard requirements;There are a few dead corners in the indoor air distribution;The concentration of volatile organic compounds in indoor air exceeds the standard seriously,the maximum value is 1.28mg/m³,and the exceeding standard rate of test points is 85.4%;In the peak period of personnel,the maximum concentration of indoor carbon dioxide reaches 2567ppm,and the over standard rate of test points reaches 73.3%;A small amount of formaldehyde in the room exceeds the standard at the measuring points;Indoor inhalable particles with a particle size of 2.5mm did not significantly exceed the standard.The results of the questionnaire survey showed that the individual’s rejection rate of indoor air quality reached 10.5%,which generally reflected that there was peculiar smell in the venues;Personnel are prone to discomfort symptoms such as"fatigue"and"nausea".Compared with geographical location,lighting and other conditions,people pay more attention to the indoor air quality of the gym.In order to make the subjective evaluation closely related to the objective data,the grey system theory is introduced in this thesis.Through grey correlation analysis,the main factors affecting indoor air quality of gym and causing discomfort symptoms were found According to the grey evaluation system,the indoor air quality of the gym is determined as light pollution level,and the pollution is the most serious in summer.Secondly,the indoor air environment of the gym is simulated and analyzed by using the numerical simulation method of computational fluid dynamics and the results of grey correlation analysis,and the ventilation optimization scheme is formulated.The simulation results show that setting the fresh air speed to 1.38m/s and the supply air temperature to 293K before the gym is officially opened,and 8-minute early ventilation for the venue can reduce the concentration of volatile organic compounds to 0.47mg/m³ in summer,and effectively reduce the impact of indoor pollutants on air quality during operation;During the peak period,the three ventilation methods of increasing the fresh air volume,adding the exhaust outlet at the accumulation of pollutants and increasing the fresh air volume at the same time can effectively reduce the carbon dioxide concentration and indoor temperature,but there are differences in the improvement of indoor air environment.It is calculated that the indoor air environment of the gym after ventilation optimization can accommodate up to 119 people to exercise at the same time,an increase of 30 people compared with before.Finally,the energy consumption under different ventilation conditions is calculated.When pre ventilation is carried out before the gym opens,the power consumption of the system increases by 58kwh;In the peak period of gym staff,the ventilation mode of adding exhaust outlet has the lowest energy consumption of the space-time regulation system,and the ventilation mode of increasing fresh air volume has the highest energy consumption of the space-time regulation system.