Research On The Strategy Of Indoor Thermal Environment Of Natural Ventilation Office Building In Chengdu

The design principle of the hot summer and cold winter area in the code for thermal design of civil buildings is "must meet the requirements of heat prevention in summer,and give due consideration to the heat preservation in winter".Based on this principle,the author explores the strategy of building an indoor thermal environment for Chengdu office building in the hot summer and cold winter area A.Based on the concept of "passive priority,active optimization",the author analyzes and summarizes the optimal single passive technology of each component of natural ventilation office building in Chengdu,and analyzes the coupling of multiple optimal single passive technologies,on the basis of which a comprehensive optimization model is established.The indoor thermal environment parameters of the comprehensive optimization model,the basic model and the target office building(tianguxingu 6)are compared and analyzed.Finally,the optimization strategy of the indoor thermal environment of the natural ventilation office building in Chengdu is put forward.The improvement of indoor thermal environment of buildings is closely related to the local climate characteristics.On this basis,the author summarizes and analyzes the climate characteristics and thermal environment of major cities in hot summer and cold winter areas.The annual average temperature in Chengdu is 16.57℃;the average dry bulb temperature in the hottest month(July)is 25.81℃;the average dry bulb temperature in the coldest month(January)is 5.78℃;it is at a good level in major cities in hot summer and cold winter areas.The annual average relative humidity of Chengdu is 82%;the maximum value appears in August,which is 85.5%;the minimum value appears in May,which is 74.8%;in the hot summer and cold winter areas,the relative humidity is in a worse level.The author also summarizes and analyzes the intensity of direct solar radiation and atmospheric pressure over the years in this area.The author conducted a questionnaire survey on several office buildings in Chengdu,and measured the indoor thermal environment parameters of one office building(Tianfu Xingu 6)in winter and summer.The results of questionnaire survey on the evaluation of thermal environment satisfaction are as follows: 71.2% and 67.9% of the respondents think that the environment is humid and hot in summer and slightly stuffy due to air influenza;72.9% and77.9% of the respondents think that the environment is humid and cold,just and slightly uncomfortable due to air influenza in winter.The results of the investigation on the indoor temperature of the target office building(Tianfu Xingu 6)are as follows: the indoor average temperature is higher than the outdoor average temperature,the standard deviation is small,the range of the average temperature difference is small,and the data is relatively centralized;and the PMV-PPD value of the target office building is statistically analyzed,the average PMV value in summer is 0.8,the average PPD value is 22%;the average PMV value in winter is-2.04,the average PPD value is 77%;the control According to the 7 thermal sensation levels of PMV,the main thermal sensation of indoor personnel is slightly warm in summer and cool in winter.The author uses DeST-c software to establish the basic model of office building,and explores the optimal single passive technology of the basic model.When the window to wall ratio of the foundation model increases from 0.2 to 0.8,the average value of indoor air temperature keeps rising,and the temperature difference between the maximum and minimum value of indoor air temperature keeps expanding.However,the maximum value of annual temperature in the indoor room shows the phenomenon of West > East > South > north;the average value of annual indoor temperature shows the phenomenon of West > South > East >north;the minimum value of annual indoor temperature shows the phenomenon of South >West > East > north.It is found that in the natural ventilation office buildings in Chengdu,the lower the window wall ratio is,the more the low temperature hours are,and the higher the window wall ratio is,the more the high temperature hours are.According to this,the author thinks that the room temperature of the building model is hot in the west,cold in the north and unstable in the East,and the best in the south.The influence of wall thickness,concrete wall and brick concrete wall,wall insulation material,window glass and sunshade on indoor thermal environment are also analyzed.It is concluded that the indoor thermal environment of 240 mm concrete exterior wall with insulation material is polystyrene foam,and the optimization strategy of indoor thermal environment for building natural ventilation office buildings.In the comparative analysis of several common window glass materials,it is found that in the South and west direction of natural ventilation office buildings in this area,coated Low-E hollow glass(low permeable)is the best way to improve the indoor thermal environment;in the north and east direction of buildings,ordinary hollow glass should be used.In the analysis of sunshade technology,it is considered that the effect of external blinds on indoor thermal environment is better.The integrated optimization model is established by using the optimal single passive technology of each component,and the coupling analysis of various optimal technologies is carried out to continuously improve the integrated optimization model.It is found that the change rule of indoor air temperature of the comprehensive optimization model is the same as that of the measured indoor air temperature of the building,but the maximum and average values of the indoor air temperature of the former are obviously improved compared with the latter.Through the coupling effect of multiple single optimal technologies,the indoor temperature hours distribution tends to focus on the comfortable temperature range of indoor personnel.Although there are also occasional high temperature in summer and occasional low temperature in winter,the author believes that the overall optimization model has improved the indoor thermal environment of the building.