Study On Key Parameters Design Of External Envelope Structure Of Passive Building In Hot Summer And Cold Winter Area

With the proposal of’2030 Carbon Peak 2060 Carbon Neutralization Goal’,China vigorously promotes and develops passive buildings to accelerate the development of building energy conservation.Due to the late start of passive building research in hot summer and cold winter areas,there are few studies on the design of envelope parameters,resulting in the slow development of passive buildings in the region.Based on the above reasons,this paper took a passive building in Hangzhou as the reference object,studied the thermal parameters of the external enclosure structure of the passive building in hot summer and cold winter areas in the view of energy consumption,carbon emission and economy.Primarily,it analyzed the climate characteristics of Hangzhou;in2020,the air conditioning system power consumption of a passive building in the region was monitored and the indoor thermal disturbance parameters during building operation were recorded;according to the building physical parameters and operating conditions,the passive building thermal model was established;then the power consumption of air conditioning system was simulated and compared with the measured value to verify the accuracy of the model.Subsequently,based on the verified model,the influence of heat transfer coefficient of external wall,roof,floor,external window and solar heat gain coefficient of external window on building energy consumption was simulated and analyzed.Orthogonal test was designed based on the above parameters to simulate the building energy consumption under each test scheme;the sensitivity analysis of energy consumption influence parameters was carried out by standardized regression coefficient method,and the total energy consumption prediction model of heating,cooling and heating and cooling was established.It was determined that the external wall of passive building in hot summer and cold winter area should be the focus of energy saving,followed by roof and outer window.Then,taken expanded polystyrene board,rock wool board and graphite polystyrene board as the objects,the energy saving effect,carbon emission and economy of each external wall insulation material were simulated and analyzed.The least square method was used to fit their thickness and carbon emissions,cost,investment payback period equations.It was found that when 122.7 mm EPS was used as external wall insulation in passive buildings in hot summer and cold winter areas,the building energy saving rate was 43.15%,the life cycle cost and carbon emissions of insulation materials were-219.34 yuan/m² and-616.60 kg CO₂e/m²,respectively,which had the best energy saving and emission reduction effect.The energy saving effect,carbon emission and economy of vacuum insulation board as roof insulation were simulated and analyzed,and the equations of thickness,energy consumption and life cycle cost were fitted.The results showed that when the STP of 32.18 mm was used for roof insulation,the energy consumption of heating and refrigeration was 17.39（kw·h）/（m²·a）,the carbon dioxide emission reduced in the operation stage was 41.19 kg/（m²·a）,and the life cycle cost was-496.73 CNY/m²,which was the optimal thickness.Eventually,the energy consumption of building models under different window types was simulated and compared to obtain the window type with low energy consumption.Compared the energy consumption of buildings with different window-wall ratios,it was found that passive buildings in hot summer and cold winter areas should choose three-layer glass+LOW-E+argon windows in the east,and the window-wall ratio was 0.25.south should choose three layer glass+LOW-E window,window wall ratio was 0.45;westward window should choose three layer glass+（green）LOW-E window,window wall ratio was 0.25;north should choose three layers of glass+（green）LOW-E window,to meet the requirements of lighting as far as possible to reduce the window wall ratio;a simplified building model was established to analyze the shading effect in different directions,it was found that the energy saving rate of the westward outward shading in summer was the highest,reaching 32.15%,followed by 18.63%in the east,18.62%in the west and 14.87%in the north.