| With the continuous increase of mine depth and the gradual increase of ground temperature,it will cause the problem of increased working environment of personnel in the mine.When the local temperature exceeds a certain temperature,thermal damage will be formed.Thermal damage is an inevitable problem in the process of deep development of mine mining.Therefore,this paper aims at the problem of excessively high working environment of personnel in the mine,and proposes a new type of anisotropic material as the thermal insulation aggregate,cement as the cementing material,and isotropic material gold mine tailings and fly ash as admixtures.Insulating concrete is used as the basic material of the roadway heat insulation material to delay the heat release of surrounding rock and achieve the purpose of reducing the ambient temperature in the roadway.The new thermal insulation concrete mixed with isotropic materials such as fly ash,tailings slag and anisotropic materials can not only save raw materials and reduce costs,but also digest and utilize a large amount of solid waste in line with the national green,healthy and sustainable development.Claim.At the same time,it has the advantages of light weight and easy construction,can effectively improve the effect of heat preservation and heat insulation,and has good economic,energy saving and environmental protection benefits,and it is worth further research and promotion.The main research contents of this paper are as follows:(1)Firstly,the influence of the content of slag,fly ash and water-cement ratio of the isotropic material on the thermal conductivity and density of the new heat insulation concrete was analyzed through orthogonal test.The experimental study found that when the fly ash content was 40%,the slag content was 30%,and the water-cement ratio was 0.45,the thermal conductivity of the experimental material reached the minimum value of 0.7249 and the minimum density of 1783.The minimum value of thermal conductivity and density was the best mix ratio.(2)Secondly,experimental and theoretical studies on anisotropic materials are carried out based on the optimal mix ratio of orthogonal experiments.The anisotropic material and tunnel temperature gradient are arranged vertically in the isotropic(thermal insulation material)material,and the influence law of the thickness of anisotropic porous media on the thermal conductivity of the isotropic material(thermal insulation material)is analyzed.(3)The experimental study shows that the thermal conductivity decreases with the increase of the thickness of anisotropic material interlayer.When the interlayer is 10cm,the minimum thermal conductivity of the specimen is 0.1821.Through the establishment of a three-dimensional model of the roadway,the anisotropic materials of different thicknesses were put into the roadway as the concrete interlayer for numerical calculation and comprehensive analysis.It was found that the insulation effect was the best when the thickness of the anisotropic material interlayer was 8cm.(4)Finally,numerical simulation and theoretical research are carried out.By changing the Reynolds number at the entrance of the tunnel,the thermal insulation performance of three different types of thermal insulation materials,namely tailings concrete(without interlayer),interlayer with anisotropy and interlayer with anisotropic material and air interlayer,is calculated,and the theoretical comparison of the calculated results is carried out.(5)It is found that when Reynolds number Re=3.2×10~5?Re=12.8×10~5,the suitable working environment temperature can be obtained;When Reynolds number Re=3.2×10~5,the temperature at the exit of the roadway is higher;When Reynolds number Re=12.8×10~5,the temperature change in the roadway was not obvious.When the insulation material is combined with 6cm anisotropic material and 6cm air sandwich,the insulation effect is best.There are 38 figures,21 tables and 102references in this paper. |
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