Study On Heat Insulation And Cooling Effect Of Solid Waste Foundation Mixed Heat Insulation Materials On Roadway With High Ground Temperature

With the exhaustion of shallow coal resources in China,coal mining has gradually shifted to deeper areas.In deep shafts,heat dissipation from high ground temperature surrounding rocks is the main cause of heat damage in mines.High ground temperature roadways affect the underground ventilation environment to a large extent due to long ventilation lines and large exposed areas,which not only increase the temperature of ventilation airflow directly through heat exchange,but also affect the cooling effect of other cooling measures.With the development of thermal insulation materials,the use of thermal insulation materials for thermal insulation and cooling in high ground temperature roadways has become a new technology for heat damage prevention and control.In this thesis,mining thermal insulation materials were developed by orthogonal method using solid waste materials such as foam and ceramic pellets,and the cooling effect of thermal insulation materials was studied by using a home-made thermal insulation and cooling simulation device for high ground temperature roadways.The thesis summarises the basic performance requirements of mining insulation materials and uses them as criteria for selecting suitable test materials.Solid waste materials such as foam granules,ceramic granules and basalt fibres were selected for the development of mining thermal insulation materials by means of component modification,and orthogonal tests were carried out to optimise the material ratios.The thermal insulation mechanism of the insulation material was also analysed from the characteristics of the solid waste material.In order to investigate the effect of thermal insulation,a high ground temperature roadway thermal insulation and cooling simulation device was developed independently,which was used as the basis for conducting a roadway rock heating test to investigate the effect of thermal insulation materials and wind speed on the thermal insulation and cooling effect.The effect of the developed thermal insulation materials and wind speed on the thermal insulation and cooling effect was investigated by comparing the temperature rise process and the internal wind flow temperature before and after spraying the solid waste-based mixed thermal insulation materials in the roadway at different wind speeds.The conclusions show that both sprayed insulation materials and increased air speed can reduce the airflow temperature and enhance the cooling effect.Numerical simulations were carried out using FLUENT software to build a high ground temperature tunnel model,and the temperature distribution characteristics of the high ground temperature tunnel before and after the large-scale application of thermal insulation materials were analysed by comparing the overall temperature distribution,coating temperature and wind flow outlet temperature,which proved the good cooling effect brought by the implementation of thermal insulation methods.The effects of various factors(coating thermal conductivity,coating thickness,wind speed,wind temperature,original rock temperature,thermal conductivity of surrounding rock)on the thermal insulation and cooling effect of the roadway were further investigated,and on this basis,the change law of convective heat transfer coefficient of high ground temperature roadway after the application of thermal insulation materials was summarized and analyzed,which has important application value for the thermal insulation and cooling of high ground temperature roadway in mines.The research results of this thesis can provide a new application material for mine thermal insulation and cooling technology,and provide a technical basis for wind temperature prediction and thermal damage prevention and control technology for insulated roadways.There are 49 figures,20 tables and 92 references in this thesis.