Research On Thermal Performance Of Thermal Insulation Glazed Hollow Bead Concrete Hollow Shear Walls

In order to adapt to the situation and the development requirements of building energy efficiency and building industrialization in our country, the group put forward to a new type of self-insulation structure system, which is thermal insulation glazed hollow bead concrete hollow shear wall structure system. The system makes full use of the excellent heat preservation and heat insulation properties of thermal insulation glazed hollow bead concrete, as well as the characteristics of light weight and small stiffness of hollow shear wall. On the one hand, it saves the construction resources; on the other hand, it improves the seismic performance and thermal performance of the wall. The system can effectively reduce the cost of whole life cycle of the construction and it has important research significance. As part of system study of the system, this paper mainly focus on the thermal performance of the system. Through the experimental study of thermal performance of thermal insulation glazed hollow bead concrete hollow shear wall, thermal analysis of numerical simulation and theoretical calculation, heat preservation and heat insulation properties of the shear wall and its change rule under different influencing factors are confirmed,which provides the basis for the system design. The main work is as follows:(1) Experimental study of thermal performance of hollow shear wall. With thermal insulation glazed hollow bead concrete hollow shear wall as the research object, the heat flow meter method is used for the thermal performance test of 2 slices of full scale specimen. The heat transfer mechanism and coefficient of heat transfer of plain concrete hollow wall under different environmental temperature and reinforced concrete hollow shear wall are analyzed to provide a reference basis for further thermal analysis of numerical simulation. The results show that when the distribution of steel reinforcement ratio of thermal insulation glazed hollow bead concrete hollow shear wall meets the specification requirement of minimum reinforcement ratio, heat transfer coefficient is 1.332W/(m2?K), which satisfies the coefficient of heat transfer limit when building system coefficient is 0.40 or less in hot summer and cold winter area. The impact range for of thermal insulation glazed hollow bead concrete hollow shear wall is small with the existence of reinforcement, the coefficient of heat transfer is only reduced by 5.1% when it is not worthy to be reinforced. The impact of factors such as temperature, environment temperature is lower than 3% on heat preservation and heat insulation properties of the wall.(2) Numerical simulation of the hollow shear wall thermal performance.Using ANSYS FLUENT software to do thermal analysis of numerical simulation for thermal insulation glazed hollow bead concrete hollow shear wall and comparing it with the test case. The results show that simulation resultsbasically match the testing results. Thermal analysis of numerical simulation using ANSYS FLUENT software can fairly reflect the wall heat transfer process of the specimens. On this basis, a new thermal analysis model is made, which is built under different parameters to compare and analyze the thermal performance of thermal insulation glazed hollow bead concrete hollow shear wall. The results show that setting the air layer between shear wall cannot significantly improve heat preservation and heat insulation properties of the wall,but when the air layer between the inner surface pasted low radiation coefficient of material or filled in thermal insulation material, heat preservation and heat insulation properties of the wall is significantly improved, and the effect is better when filled with thermal insulation material. The heat transfer coefficient is0.752W/(m2?K), which meets the value limit of heat transfer coefficient in hot summer and cold winter area, and basically meets the value limit of heat transfer coefficient when the building is higher than 9 layers in cold area. Steel has certain effect on heat preservation and heat insulation properties of the shear wall. When the distribution of longitudinal steel reinforcement ratio is 0.26%,0.67% and 1.37%, heat transfer coefficient increases 5.0%, 6.6%, 8.8%compared with the wall not worthy to be reinforced. Under the condition of normal reinforcement, the steel will not have great influence on heat preservation and heat insulation properties of thermal insulation glazed hollow bead concrete hollow shear wall structure.(3) Heat transfer coefficient calculation and analysis of the hollow shearwall. Using the current suggested specification formula to calculate the heat transfer coefficient of thermal insulation glazed hollow bead concrete hollow shear wall, then comparing and analyzing with the simulation values as well as the test results. The results show that using specification proposed formula to calculate the heat transfer coefficient is in good agreement with the experiment and simulation results, so heat transfer coefficient calculation of thermal insulation glazed hollow bead concrete hollow shear wall can reference to specification recommended formula. With the air layer development of hollow shear wall, heat transfer coefficient is 72% lower than the ordinary concrete wall,the thermal resistance between the air layer increases significantly, and the thicker of the air layer, the better of heat preservation and heat insulation properties of the wall.