Study On Efficient Cooling Method Of Coal Face In High Temperature Mine

With the increase of mining depth and the influence of geothermal gradient,the thermal damage of working face is becoming more and more serious.In high temperature coal mining face,surrounding rock heat dissipation and mechanical and electrical equipment heat dissipation are important factors that cause thermal damage in working face.High temperature environment will cause serious harm to the physical and mental health of underground workers,and also seriously affect the safety of mine production.Therefore,it is necessary to carry out efficient cooling method research for high temperature heat damage of coal mining face.In this paper,the high temperature heat damage problem of 7302 working face in Zhaolou Coal Mine is taken as the research object.Through field observation,theoretical calculation and numerical simulation,the problems existing in the existing working face cooling system and cooling scheme are analyzed,and the optimization and improvement methods are put forward.Based on the change of wind flow thermal parameters in the original state,the heat source of the working face is divided into sections,and the heat dissipation of the heat source in each section is calculated,and the distribution law of the heat source of the working face is obtained.Through the observation and analysis of the operation of the equipment in the cooling system,it is found that the actual cooling capacity of the air cooler is low.The main reason is that the water supply pressure does not meet the design requirements,and there is a hydraulic imbalance in the cold water pipe network system.For the problem of low refrigerating capacity of air cooler,the hydraulic calculation of cold water pipe network in the working face is carried out,and the unfavorable pipe sections in the pipe network are determined.The pipe sections are optimized and improved according to the calculation method of economic pipe diameter,so as to increase the node water pressure of each air cooler in the working face and make it meet the design requirements.The experimental experimental system of flow regulation characteristics of balance valve is established,the variation law of valve flow is obtained,and the layout scheme of balance valve in pipeline is put forward.The cold water pipe network monitoring system is designed to realize the remote monitoring and control of pipe network flow.In view of the poor effect of the existing cooling scheme,the full-scale model of the working face is constructed by COMSOL software to simulate the cooling status.The simulation results are compared with the field observation results to verify the feasibility of the simulation.Based on the shortcomings of the existing cooling schemes,an improved cooling scheme is proposed and the simulation effect is analyzed.The layout length of the air duct behind the air cooler in the air inlet roadway and the reasonable layout of the air cooler over the working face are determined.After the field application of the improved cooling scheme,the ambient temperature of the working face has been significantly improved.