Research On Energy Saving Technology Of Prefabricated Building Envelope Structure In Cold Region

With the continuous and rapid development of China's economic construction,the increasing demand for energy in the construction industry has become the focus of attention of the whole society.The assembly-type building is once again being promoted for use in buildings by means of its industrialized integrated production and construction methods.At the same time,energy-saving technologies are applied to the prefabricated building envelope structure,which can save energy during the entire life cycle of the building.It has certain theoretical significance and application value for the development of China's building energy conservation.This article takes the prefabricated concrete building in the cold area as the research object,and focuses on the energy-saving technology of the prefabricated building envelope structure.In order to further understand the thermal performance of the prefabricated building envelope structure,the existing assembly building and industrialization base in Xi'an area was investigated and the survey data was analyzed.The main problems in the prefabricated buildings in the Xi'an area are that the thermal performance of external protection structures can not meet the requirements of regional energy-saving design standards and green building evaluation standards,weak connection of key parts,application of energy-saving technologies,and low application rate.The corresponding energy-saving improvement measures were proposed for the problems,including the use of building thermal insulation integrated walls,the selection of high-quality thermal insulation materials,the optimization design of the weak part construction measures,and the integration of energy-saving technologies and prefabricated buildings.In order to further determine the thermal parameters of the prefabricated building envelope in cold areas to ensure that the indoor temperature of the building is within the comfort temperature range for the whole year,DeST-h is used to establish the basic model to simulate the heating and cooling load of the prefabricated building.It is concluded that the thickness of the three types of insulation materials for the wall of the envelope is 70mm,and that for the insulation of three kinds of insulation materials on the roof is 60mm.The window with the coated composite insulating glass is preferred for the outer window,and the ratio of the south to the window and wall is better.It is advisable to take 0.6.The east,west and north facing windows should minimize the setting of the window-to-wall ratio when meeting the specifications.In order to verify the scientificity of numerical simulation data,according to the conclusions of the numerical simulation study of the external structure of prefabricated buildings,the overall energy-saving optimization of the assembly-type residential engineering project in Xi'an was conducted,and the overall energy-saving optimization scheme was proposed to compare and analyze the energy of the original program.The consumption simulation results show that the overall energy efficiency optimization programs I,II and III have improved the energy efficiency of heat load by 40%,47%and 56%respectively compared to the original scheme,and the overall energy saving optimization scheme III has the best energy saving efficiency.The optimized energy-saving scheme can ensure that the thermal parameters and building energy consumption of the external structure of the prefabricated building meet the requirements of the green building evaluation standard.To sum up,the results of this study can provide reference for the energy-saving design of the external protective structure of fabricated buildings in cold regions and promote the further development of fabricated buildings in China.