Thermal Analysis Of Low Energy Energy Building Components Of Light Steel Structure In Cold Area

With the deepening of industrialization in China,the state's support for prefab building is increasing.At present,most of the prefabricated applications are in residential buildings,which are mainly assembled with concrete components.However,temporary buildings like vulcan mountain and thor mountain not only need to be built quickly,but also can be disassembled at any time.The abandoned prefabricated components can also be reused.Therefore,for this kind of temporary construction,the application of prefabricated modules to light steel structure system is a good choice.Two hospitals adopted modular light steel structure system,This construction system is framed by light steel structure,and adopts factory standardized production and on-site integrated installation,the factory site integration installation,greatly shorten the construction cycle,and can remove and moving at any time,without any pollution to the environment,abandoned light steel components can also be reused,belongs to the true sense of green building.As a kind of high-end carrier,the modular building of steel structure has introduced the design concept of ultra-low energy consumption and zero energy consumption to meet the requirements of the sustainable development of the future construction industry.In recent years,in order to realize the efficient use of energy and reduce excessive emissions of greenhouse gases such as carbon dioxide,various countries have introduced policies one after another.Green buildings,passive buildings,near-zero energy buildings,even zero-energy buildings,and production capacity buildings have emerged one after another.It is believed that the combination of light steel structure modularization and ultra-low energy consumption will become a new research focus in the future construction field.But as a result of light steel structure building in light steel keel component too much,and the coefficient of thermal conductivity of light steel and its surrounding the heat preservation material differs very big,will produce severe thermal bridge effect,it has violated the ultra low energy consumption building in the principle of "thermal bridge",So in this paper,a set of standardized methods for the envelope of light steel structure buildings with ultra-low energy consumption modules is developed,including the external system approach,ground system approach,roofing system approach,no heat bridge design through wall tube,realized the light steel structure modular construction of low energy consumption,The annual heating demand of light steelstructure buildings with different number of modules and the proportion of energy consumption of each part of the envelopment structure in cold areas are also calculated.Firstly,the steady state thermal analysis of each envelope structure in light-steel structure building is carried out by ANSYS finite element analysis software,so as to understand the parts of the light-steel structure building which are prone to generate heat Bridges.To accurately calculate the palisade structure under the annual dynamic energy consumption,the article will solar radiation,wind speed and other outdoor environmental factors into consideration,and puts forward the methods of dealing with the boundary conditions and measured hourly outside wall through the experiment in vitro transient wall temperature and software simulation,the results of ANSYS software is verified the correctness of the transient simulation boundary conditions when the processing,provide the basis for later energy consumption calculation.Then,the article respectively using ANSYS simulation software of prefabricated light steel structure building outside wall,l-type corner,roof,Corner of the ground,window and wall tube parts of the bridge prone to heat the transient simulation and calculate the annual energy consumption level,at the same time to maximize reduce thermal bridge of additional heat consumption for calculating target,calculate the optimum thickness of palisade structure heat insulation layer,give cold areas prefabricated light steel structure building to realize ultra-low energy consumption when the heat transfer coefficient of enclosure structure recommended value.In addition,because the transient simulation time of ANSYS is too long,this paper proposes a new calculation method,comprehensive heating hour method,to replace the transient simulation,which can be easily used by designers.But it is important to note that due to the regenerative ability of the soil,and its impact on the initial conditions for the calculation results,and for soil,the temperature of each layer is different,so for the ground during the transient simulation is relatively complex,and the ground position is different,the comprehensive degree of heating,count method is not applicable.Finally,on the basis of above research results,based on the theory of heat transfer calculation is given standard module HuaQing steel structure building the thermal bridge parts and proportion,the palisade structure of energy consumption and energy consumption proportion and standard modular homes in heating demand,and calculate the to reach the level of cold region ultra-low energy consumption in heating demand standard required minimum number of modular light steel structure building.