Research On The Influence Of Air Interlayer And Rib Wall On The Heat Transfer Characteristics And Mechanical Properties Of Hollow Block

Building energy efficiency is not only an important measure to promote the production and utilization of green building materials,but also a trend of sustainable development in the world today.Improving the thermal insulation of multi-row-hole blocks is one of the ways to reduce the energy consumption of building envelopes at this stage,and there is a common problem in the process of optimizing the heat transfer coefficient of the blocks:It is not possible to balance the relationship between the thermal insulation and compression resistance of the block.Therefore,improving the thermal properties of blocks on the basis of satisfying the compressive properties of multi-row-hole blocks is an important issue that needs attention.This thesis uses a combination of numerical simulation and experimental research to study the thermal insulation performance and mechanical compression resistance of multi-row-hole blocks.As follows:1.The heat transfer and compressive strength of a typical multi-row hole block are simulated and analyzed.At the same time,the heat transfer coefficient and ultimate load are measured through experiments to verify the numerical simulation of the research object using ANSYS-FLUENT and ANSYS-MECHANICAL feasibility of calculation.2.Study the factors affecting the thermal performance and compressive performance of the block,and draw the following conclusions:Thermal performance:Under the condition of certain porosity,the effects of porosity,air layer arrangement,air layer length and rib wall thickness on the thermal insulation performance of the block are studied,and it is obtained that the heat transfer coefficient of the rectangular hole is the smallest;When the air interlayer arrangement is 1:2,the thermal insulation performance is the best;the heat transfer coefficient of the hollow block decreases with the increase of the air layer length;the heat transferred through the rib wall decreases with the increase of the thickness of the cross rib and increases with the increase of the thickness of the longitudinal rib.In terms of compressive performance:Under the condition of a certain porosity,the influence of the porosity,air layer arrangement and rib wall thickness on the compressive performance is studied,and it is obtained that the ultimate load of the circular hole is the largest,and the hole pattern is easier to produce with edges and corners;when the air interlayer arrangement is 1:1,the load distribution of the block is more uniform,and the ultimate load is the largest;the ultimate load of the block increases with the increase of the thickness of the rib wall.3.According to the specifications and research results,8 types of multi-row-hole blocks are designed and numerically simulated for heat transfer and compression.The Analytic Hierarchy Process is used to obtain the best overall performance in terms of thermal performance,compression resistance,and economy.The heat transfer coefficient of the second optimized block is 0.421 W/（m~2·k）and the compressive strength is7.432MPa,which meets the national 65%energy-saving requirements.