Influence Of Different Insulation Ways On Net Heating Quantity Of Wall Envelopes

Energy consumption of China is mainly in the three areas of construction,transportation and industry,and building energy consumption accounts for a third of the total energy consumption of the whole society.In the whole building energy consumption,through the building envelope heat loss accounts for about 70%,the heat loss through walls accounted for about 33% of the building envelope heat loss,so through the study of the thermal insulation of building envelope to reduce the heat loss of the interior,in turn,reduce the energy consumption of building heating has high research significance.The lower reaches of the Yangtze River region climate type is subtropical monsoon climate,in general,the weather is cold and wet,the outdoor minimum temperature is 0 ? in winter,and mostly low-rise and multilayer residential buildings in suburbs of the city and rural areas is still widely used brick structure with low cost,simple construction and no thermal insulation system,in order to maintain indoor comfortable thermal environment,usually need a lot of energy consumption.In this paper,the influence of different heat preservation methods on the winter energy saving of residential buildings in this area is studied from the internal and external thermal insulation forms of brick wall and the new type of self-insulation wall.Taking a five floors of residential building in Shanghai as an example,studying the conditions of building envelope absorb solar energy during the winter from the way of heat preservation,outdoor air temperature,continuous days of sunshine,analyzing the thermal insulation of residential buildings in the lower reaches of the Yangtze River from the angle of net heat of the wall.In this paper,two climatic conditions,three kinds of heat preservation methods and four different outdoor minimum air temperatures were simulated.The results show that the temperature of the internal insulated brick wall and the self-insulation wall is highly affected by the outdoor temperature,the diurnal variation is huge with an abrupt change in climate.The heating quantity during daytime of the internal insulated brick wall and the self-insulation wall is large,but at night,there is more heat dissipation,and the total heating quantity is decreased with the increase of sunshine days.Besides,the temperature fluctuation of external insulated brick wall is small,and the influence by the outdoor air temperature is also small,under the action of the outer insulation layer,the solar energy absorbed by the wall during the day is small,but the convective heat dissipation in the night is also less,and it is not related to the number of days of continuous sunshine.In conclusion,for the middle and lower reaches of the Yangtze River,new self-insulation walls are not conducive to building energy conservation.In areas with long and sunny days,the exterior insulation of brick walls is more conducive to building energy conservation in the region.For areas with few continuous sunny days,internal insulation is beneficial to reduce heating energy consumption.