Optimization Design For Blocking Thermal Bridge Of Embedded Exterior Wall Of Low Energy Assembly House

The exterior wall thermal insulation forms of prefabricated residence in severe cold area mainly include external insulation,internal insulation and other composite insulation.When the exterior wall adopts composite thermal insulation form,the thermal bridge of prefabricated exterior wall panel and structural connection node will also increase the average heat transfer coefficient of external wall,affect the heat transfer of external wall,and increase the building energy consumption.The existing research on building thermal bridge mainly adopts one-dimensional calculation method.However,for the complex thermal bridge temperature field of the connection nodes during the installation of prefabricated external wall panel of prefabricated residence,it is impossible to analyze and study the complex twodimensional heat transfer problem by using one-dimensional calculation method,which can improve the accuracy.Therefore,attention should be paid to the research on heat transfer of thermal bridge by two-dimensional and other methods.The embedded external wall installation method of prefabricated residence makes the interior space corner of the building without prominent column structure,and the plane layout is more flexible,which increases the internal space use area.However,structural thermal bridges such as beams and columns increase the building energy consumption.In this paper,combined with the climate conditions in winter in Harbin,and taking the typical unit wall of prefabricated residential embedded external wall as the basic model,this paper selects the thermal bridge of precast external wall panel and central column connection node,prefabricated external wall panel and beam connection node thermal bridge,prefabricated external window and prefabricated external wall panel connection node thermal bridge to study,and the temperature distribution map,heat transfer coefficient of thermal bridge line,and the average of external wall are selected The heat transfer coefficient is used to analyze the influence of heat bridge between prefabricated exterior wall panel and structure joint on external wall heat transfer.PTemp twodimensional heat transfer calculation software is used to simulate and analyze.The analysis process is divided into three steps: theoretical analysis,simulation analysis and optimization design.In the theoretical analysis part,firstly,the related theories of external wall heat transfer are analyzed.In the simulation analysis and optimization design part,taking the basic model as a typical example,this paper analyzes the embedded external wall broken bridge structure of prefabricated residence in severe cold area.The p Temp software is used to carry out two-dimensional simulation analysis on the broken bridge structure of the central column,the beam broken bridge structure and the external window connection broken bridge structure.The influence of different types of broken bridge structure on the average heat transfer coefficient of the external wall is compared and summarized The optimized scheme design and improvement measures are put forward.Finally,the optimal design scheme and improvement measures are selected according to the simulation results.Finally,an economic and reasonable structural optimization scheme for embedded external wall of prefabricated residential buildings with low energy consumption suitable for severe cold regions is obtained.