Research On High-performance Exterior Wall Self-insulation System In Hot Summer And Cold Winter Area Based On Sintered Shale Products

The external thermal insulation system of building envelope in hot summer and cold winter area is mainly used,which has good thermal insulation performance,but there are some problems such as poor durability and fire resistance.The system with self-insulation block as the main material can avoid the above disadvantages,but the related research and application are relatively scarce.In particular,few studies have focused on the influence of hole structure on the heat transfer characteristics of blocks.In this paper,by analyzing the heat transfer mechanism of self-insulation block,the method of combining numerical simulation and experiment is used to optimize the pore structure of the block.The traditional sintered shale is selected as the base material frame,and the ultra-light foam concrete is used as the core material to prepare the sintered shale composite self-insulation block.The thermal performance of the wall meets the requirements of building energy saving by 75%,and further explores the adaptability of the self-insulation wall system in the hot summer and cold winter area,and clarifies the technical optimization measures and supporting material selection scheme of the system.The main research contents and results are as follows:1)Self-insulation block pass design and theoretical analysis.In this paper,self-insulation blocks with nine kinds of holes are designed.The influence factors and heat transfer characteristics of the nine kinds of holes are analyzed by ANSYS simulation software.The heat transfer law of the block is obtained:the thermal resistance of the block increases first and then decreases with the increase of the cavity size ratio.It is positively correlated with the thermal extension line coefficient and the thickness of the core material,and negatively correlated with the thermal conductivity of the matrix material and the core material.The relationship between the linear coefficient and the thermal extension is:R?=R_t×（0.28×L_i/L₁+0.7）;then,the stress distribution characteristics and compressive properties of the block are studied by numerical simulation.Finally,on the basis of the above,the multi-objective optimization of the key parameters of the block is carried out,and the best block type is W3type.2)Optimization design of ultra-light foam concrete.In this paper,the thermal conductivity 0.08 W/（m·K）is taken as the design goal,and the effects of gel material,fly ash,foaming agent and water-cement ratio on the performance of ultra-light foam concrete under different foaming methods are investigated.The results show that the optimal ratio of ultra-lightweight foamed concrete prepared by chemical foaming method is A3B4C4,that is,fly ash content 25%,foaming agent 11.7%and water-cement ratio 0.55.The measured thermal conductivity is 0.056～0.062 W/（m·K）;using sulphoaluminate cement as gel material,ultra-light foam concrete was prepared by physical foaming method.The foam content was 8%～9%,and the measured thermal conductivity was 0.066～0.072 W/（m·K）.The physical properties and production costs of ultra-lightweight foamed concrete in the two foaming methods are analyzed,and the physical foaming method is recommended for engineering applications.3)Preparation and performance test of sintered shale composite self-insulation block.Filling the optimized ultra-lightweight foam concrete in the reserved hole of W3 block,the high-performance sintered shale self-insulation block is compounded.The heat transfer coefficient of the wall specimen is 0.69 W/（m·K）by the hot box method.The average compressive strength of the single block is 4.78 Mpa,and the strength grade reaches MU5.4)Study on the adaptability of self-insulation wall system in hot summer and cold winter zone.In this paper,De ST energy consumption simulation software is used to establish an office building based on self-insulation wall system.By analyzing the influence of window type,external wall material,roof material type and thickness on building energy consumption,it is concluded that the energy saving rate of envelope structure increases with the decrease of heat transfer coefficient,among which the energy saving rate of wall material is the highest,and the energy consumption per unit area is reduced by 9.61 KWh per year,followed by window type,and finally the type and thickness of roof material.Then,considering the selection of supporting materials for the self-insulation wall system,the influence of composite bricks and masonry mortar on the thermal performance of the sintered shale composite self-insulation wall system is theoretically calculated:using the composite brick masonry wall designed in this paper,it is 36.23%lower than the traditional porous brick;the self-insulation wall using 5 mm vitrified microsphere masonry mortar is 26.08%lower than that of 20 mm cement masonry mortar.Finally,the material cost and carbon emission of the self-insulating block were analyzed in detail,and it was concluded that the economic benefit of the sintered shale composite self-insulating block was increased by 43.7%and the carbon emission was reduced by 8.36%,which is better than the comprehensive benefit of the concrete benzene plate composite block in the current market.