Study Influence Of Connector And Splicing Form On Thermal Performance Of Prefabricated Sandwich Insulation Wall

With the acceleration of industrialization of buildings,prefabricated buildings using prefabricated sandwich insulation walls are being widely promoted.However,the large number of connectors used in the production process of the sandwich insulation wall and the gaps generated during the splicing process are prone to thermal bridge effects,which affect the overall thermal performance of the wall and cause deviations in the calculation of the heat transfer of the wall.At present,most researches on sandwich insulation walls focus on the shear resistance of connectors,the thermal performance of the wall itself,and the waterproof performance of the splicing joints.Therefore,to study the thermal bridge effect of connectors and splicing joints,to obtain the influence of connectors and splicing joints on the thermal performance of the prefabricated sandwich insulation wall,and to correct the heat transfer coefficient,is the key to accurately calculate the wall’s heat transfer.According to the above problems,this paper takes the sandwich insulation wall with different types of connectors and different splicing forms as the research object,using the COMSOL Mutiphysics software to calculate the heat transfer of the wall,and the influence of thermal bridge effect produced by connectors and splices on the wall is studied,the wall heat transfer coefficient is corrected,the following conclusions are obtained:The influence of different types of connectors on the heat transfer coefficient of prefabricated sandwich insulation wall:(1)The thermal bridge effect of sandwich insulation walls using FRP connectors can be ignored.The heat transfer coefficient correction rate of the wall using truss connectors,plate and pin connectors is about 4%,3%～16%.The influence of horizontal seam on the thermal performance of prefabricated sandwich insulation wall:(1)When the gap created by the prefabricated sandwich insulation wall spliced with the floor slab is made of unfilled,filled with polyurethane and rock wool,the effect of thermal bridge effect on the heat transfer coefficient of the wall can be ignored.When the cement mortar is filled,the correction rate of the wall heat transfer coefficient caused by the bridge effect reaches about 10%.(2)No matter what kind of material is filled in the gap created by splicing the prefabricated sandwich insulation wall with the balcony board,the correction rate of the wall heat transfer coefficient caused by the thermal bridge effect reaches about35%～90%.There is a risk of condensation on the wall in the severe cold zone A,so it needs to be insulated,and the wall in the rest of the area will not be dew.(3)It is recommended to fill in the gap with polyurethane first,then unfilled and finally cement mortar.Influence of vertical seam on thermal performance of prefabricated sandwich insulation wall:(1)For the prefabricated sandwich insulation wall with in-line structure,when the splicing joints are filled with polyurethane 、 rock wool and no padding,the thermal bridge effect may not be considered.When the joints are filled with concrete,the correction rate of the wall heat transfer coefficient caused by the thermal bridge effect is about 17%～37%.(2)For T-shaped prefabricated sandwich insulation walls,when the splicing joints are filled with polyurethane、rock wool and no padding,the effect of thermal bridge effect on the heat transfer coefficient of the wall can be ignored.When filling concrete,the correction rate of the wall heat transfer coefficient caused by the thermal bridge effect is about 24%～49%.(3)For the L-shaped prefabricated sandwich insulation wall,when the insulation layer materials are XPS,EPS,PU,the correction rate of the wall heat transfer coefficient caused by the thermal bridge effect is about 9%.(4)In order to prevent condensation on the wall,it is recommended that insulation materials be the first choice,followed by no filling,instead of filling concrete directly.Through the above-mentioned theoretical analysis and numerical calculation,the influence of connectors and splicing forms on the thermal performance of the prefabricated sandwich insulation wall is obtained,and the heat transfer coefficient of the prefabricated sandwich insulation wall is corrected,which provides a reference for practical engineering applications.