| At present,the energy consumption of buildings in China accounts for about 1/3 of the total energy consumption of the society,and building energy conservation is increasingly important.One of the important means for building energy conservation is to improve the building exterior-protected construction.With the development of the industry and the requirements of national policies,the industrialization of construction is an inexorable trend,and because of the improvement of energy-saving standards,single-material walls cannot meet the requirements of energy-saving standards.Prefabricated sandwich insulation composite wallboard has many advantages such as factory prefabrication,simplifying construction procedures,reducing on-site wet work,good thermal insulation,fire prevention,durability,mechanical strength,etc.Research on this kind of wallboard is of great significance to the development and application of building energy-saving technologies.In this thesis,through the combination of theoretical analysis,test and numerical simulation,a kind of prefabricated sandwich insulation wallboard with excellent thermal performance is developed.Then the simulation analysis of building energy consumption with different external wall systems and applicability comprehensive evaluation are carried out.Get the following main conclusions:(1)Through orthogonal test and analysis,a kind of lightweight concrete mix ratio for sandwich wall structure is obtained.The content of cement is 400 kg/m~3,the content of flyash is 70 kg/m~3,the content of water is 190 kg/m~3,the content of ceramsite is 220 kg/m~3,the content of pottery is 200 kg/m~3.The contents of fiberglass,polymer emulsion,air entraining agent,aerogel are 0.6%,10%,0.2%,1.5%of cement quality,respectively.The lightweight concrete has a dry density of 1101.8 kg/m~3,thermal conductivity of 0.421 W/(m·K),compressive strength and splitting tensile strength of 10.3 MPa and 1.68 MPa,respectively.(2)On the basis of the theoretical calculation to meet the minimum thickness of the insulation layer,the fuzzy comprehensive evaluation method based on the analytic hierarchy process(AHP)is used to determine the best scheme for the material and thickness of the insulation layer.This scheme is 50mm thick on both sides of the structural layer,and insulation material selection 100mm thick foam glass,The wall heat transfer coefficient is calculated to be 0.369 W/(m~2·K),thermal inertia index is 2.83.(3)Simulation of thermal performance of wallboards using fiber reinforced plastic(FRP)connectors and steel bar truss connectors demonstrate that steel bar truss connectors will produce obvious thermal bridges and have serious thermal defects.The prefabricated sandwich insulation composite wallboard developed in this thesis uses fiber reinforced plastic(FRP)connectors.The simulation results of the integrated heat transfer coefficient of the wallboard are 0.404 W/(m~2·K).(4)The structure and dimensions of the prefabricated sandwich insulation composite wallboard were designed and trial produced,and the thermal performance test was carried out.The complex heat transfer coefficient of wallboard was 0.398 W/(m~2·K),which was a difference of only 1.49%from that of the numerical simulation,verifies the consistency of both.And it is proved that the wallboard will not produce condensation on the surface when applied to buildings in Xuzhou(Cold area).(5)Taking the public building and residential building in Xuzhou as an example,through the applicability comprehensive evaluation,the energy consumption of different exterior wall systems is simulated and analyzed,which proved that the prefabricated sandwich insulation composite wallboard developed in this thesis has excellent building energy-saving effects.The applicability relative membership degree of wallboard developed in this thesis is compared with mineral wool external insulation ALC wallboard and XPS sandwich wallboard has been slightly improved.And it is proved that the prefabricated exterior wallboard system is worth popularizing. |
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