Study On The Influence Of Thermal Bridge On Heat Transfer Characteristics Of Prefabricated Wall

China's economic and social development is undergoing transformation and upgrading.Prefabricated buildings,which improve production efficiency and quality,shorten construction period and reduce resource consumption,should be developed.Low energy consumption buildings which fully exploit the potential of building energy conservation should be born.In this paper,numerical simulation is used to study and analyze the heat transfer characteristics of sandwich insulation wall structure of prefabricated + low-energy buildings.In this paper,numerical simulation software is used to analyze the heat transfer characteristics of the heat bridge between the prefabricated wall and the connecting nodes of the wall.Qualitative illustrates the thermal bridge of prefabricated wall had a great effect on heat transfer characteristics.Then the heat transfer characteristics of the heat bridge of the prefabricated wall are studied and analyzed.The prefabricated wall structure is decomposed and the prefabricated unit module wall model is established.The influence factors of thermal bridge effect on thermal resistance of prefabricated wall are analyzed.The factors that determine the thermal bridge's influence on the heat transfer characteristics of the assembled wall,such as the diameter and spacing of the steel bars,the thickness and material of the insulation layer,the diameter of the wire mesh and the size of the mesh,are approximately reduced to different thermal resistance correction coefficients.By means of numerical simulation,the influence law of the above influencing factors on the heat transfer characteristics of the wall is analyzed,and the corresponding thermal resistance correction coefficient of each influencing factor is calculated on this basis.Four sets of models were established to verify the thermal resistance correction coefficient obtained by numerical simulation.The error is limited to 6%,and the correction coefficient of thermal resistance can provide a basis for calculating the thermal resistance of prefabricated wall considering thermal bridge effect.Finally,a practical project case is used to calculate the thermal resistance of the prefabricated wall considering the thermal bridge effect.Compared with the case without considering the thermal bridge effect,the difference can be more than 70%.This paper provides a theoretical basis for the influence of thermal bridge on heat transfer characteristics of prefabricated wall.It provides a method for calculating the thermal resistance of prefabricated wall with heat bridge and a basis for engineering application.