Analysis And Improvement Of Thermal Bridge Of Building Envelope Based On A Prefabricated Building

In the context of the global shortage of resources and the increasing awareness of environmental protection,how to save energy as much as possible while ensuring economic development has received widespread attention from the society.Building energy consumption is an important part of China’s energy consumption.The reduction of building energy consumption caused by the heat bridge effect has always been the focus of research.On the one hand,the development of energy saving and green has put forward higher requirements for the accurate analysis of building performance.On the other hand,new technologies such as assembly have led to new building structures,and the thermal bridge structure has become more complex and diverse.Quantitative analysis and improvement research on the thermal bridge of the protection structure becomes necessary.Based on a prefabricated building,this paper first identifies three typical thermal bridges: balcony,air conditioning panel and bay window.The thermal bridge of the bay window is unique to the project.Through the finite element analysis,the temperature field and heat flow changes were analyzed,and the improvement potential of the thermal bridge thermal insulation of the enclosure was further analyzed by the calculation of the equivalent heat transfer coefficient.The results showed that the corresponding heat insulation method was adopted.After that,the thermal insulation performance of the envelope structure has been improved,and the equivalent heat transfer coefficients of the balcony,air-conditioning panel and bay window have been reduced by 21.98%,15.74% and 29.55%,respectively.This data can also be used in subsequent energy analysis..On this basis,this paper further establishes the energy consumption analysis model of the prefabricated building,and conducts dynamic energy simulation research for the following three aspects: 1)The impact of thermal bridge on building energy consumption.The results show that the existence of thermal bridge has a significant impact on the building heating energy consumption in winter,which increases energy consumption by 10.16%;2)the energy saving potential of thermal bridge thermal insulation improvement.The results show that the heat-dissipation measures have obvious energy-saving effects.The heat-breaking heat of the bay window reduces the energy consumption by 6.17%.The heat loss of the other two thermal bridges further reduces the annual energy consumption by 1.17%;3)Heat The change in energy consumption of the bridge level.The analysis shows that with the increase of the degree of thermal bridge,the energy consumption of building energy is basically proportional,the average rate of change is 2.77;4)the analysis of the influencing factors of heatblocking energy-saving potential of thermal bridge.Studies have shown that climatic conditions,insulation forms,equipment operating shifts,etc.have a greater impact on energy-saving effects.In this paper,the thermal performance of the thermal bridge of the enclosure is analyzed from two aspects: heat transfer analysis of thermal bridge components to dynamic energy simulation of buildings.The research results can provide reference for energy-saving design of building envelopes.