Study On Temperature Effect Of Thermal Bridge In Assembled Low Energy Buildings

With the development of building energy conservation work in China.Passive ultra-low-energy buildings have attracted people's attention because of their superior thermal insulation performance and good indoor thermal comfort environment.So combining the rapid construction characteristics of prefabricated buildings with the energy saving and comfortable advantages of ultra-low-energy buildings,It is necessary to explore a new type of prefabricated ultra-low-energy building combining prefabricated components to achieve a heat-free bridge.In this paper,the finite element simulation analysis of the temperature effect of the thermal bridge on the assembled ultra-low energy steel structure model house in Tangshan is carried out by using ANSYS finite element software.The thermal bridges studied include T-type and L-thermal bridge nodes in different insulation forms and preheated prefabricated siding window-hole thermal bridge node models with external insulation under four different conditions.The simulation includes temperature field and heat flux field.The heat transfer temperature field and heat flux field of the L-type and T-type joints of fabricated steel structures were studied.It was found that the steel structure at the joint seriously damaged the stability of heat transfer.There are obvious temperature fluctuation and heat flux fluctuation in the connection part of the two structures,which can cause condensation at the joints of the steel columns and damage the indoor environment.Therefore,special treatment is needed.Through the heat transfer simulation analysis of the hot bridge joint at the window opening of prefabricated exterior wall panel.It is pointed out that the energy saving effect of plug-in installation is obviously greater than that of embedded installation.And choose the window frame with better thermal insulation performance can significantly increase the temperature of the inner surface of the wall to avoid condensation phenomenon.And the window hole reinforcement material greatly increases the maximum heat flux at the window hole node,causing a certain degree of heat loss,which can be well solved by replacing it with materials with better insulation performance.In this paper,the thermal bridge parts of the steel structure residence with ultra-low energy consumption are simulated and analyzed,and the methods that can weaken theeffect of the thermal bridge and reduce the influence range of the thermal bridge are put forward,which can provide reference for future research.