Research On Thermal Performance Of Load-bearing And Thermal Insulation Integrated Floor And Wall Panels

Because of the excellent seismic performance and the high industrialization level of prefabricated steel structrue buildings,developing prefabricated steel structure has become one of the most important national policies.Normally,prefabricated steel structure buildings are composed of four parts: structural system,containment system,built-in system and pipeline equipment system.In order to improve the integration level of steel prefabricated structure assembly building,one kind of load-bearing thermal insulation integrated system is proposed.The system devides buildings into multiple components such as wallboards,floors and stairs,which are prefabricated in the factory.The wallboard is the integration of load-bearing and thermal insulation.The floor is the lattice floor slab includes insulation layer.The system achieves the realization of the integration of the structure system,containment system,built-in system and pipeline equipment system.In order to study its thermal performance,so as to provides theoretical basis for engineering application,the thesis is supported by the National Key Research and Development Program（SQ2020YFF0426523）,and the combination of practice and theory is adopted to study the system.Three specimens were designed with the thickness of insulation layer as variable,then carried out the Calibration hot-box test for the three specimens.Finally the average thermal resistance and heat transfer coefficient are obtained.The results show that the heat transfer coefficient decreases as the thickness increases.But the relationship between the thickness of foamed concrete and the heat transfer coefficient is not linear.In order to compare the thermal performance of different kind of thermal insulation material,a kind of A-Level fire-proof material is put forward.The research content its advantages and disadvantages,then we get its heat conductivity coefficient through Guarded hot-plate apparatus.A formula for calculating the average thermal resistance of integrated wallboard is presented.According to the traditional method,one kind of one-dimensional simplified calculation method is obtained,the calculation model is established,the calculation formula is derived.The finite element model is established by using ABAQUS software,the law of temperature transfer under three-dimensional heat transfer condition is analyzed,the heat transfer coefficient of the specimens is obtained.Compare the results obtained by various methods,the reaults show that one-dimensional calculation method has high precision.It provides theoretical supports for practical engineering.The thermal performance of load-bearing thermal insulation integrated system is studied by using the same method.The final results show that there is thermal bridge effect in the part of the wall panel with C-shaped steel keel,which has great influence on the thermal performance of wall panels.In order to satisfy the energy requirements of floor,it is an effective practice to lay at least 70 mm polystyrene panels on the floor surface.The thesis carried out a systematic study on load-bearing thermal insulation integrated system,fills the gap in the thermal insulation field,provides theoretical support for practical engineering.