Research On Liquid Carbon Dioxide Cooling System Of Heading Face

In China,the utilization of coal resources still accounts for a large proportion,while the coal that can be mined in the shallow part has been basically mined.Most of the coal is in deep rock formations.In order to obtain more coal resources,only deep mining can be carried out.Deep well mining is often accompanied by high temperature and heat damage,which has a great impact on mining.Therefore,in order to solve the problem of high temperature heat damage in deep wells,some cooling measures must be taken.For the whole mine to cool down,the cooling system has a series of problems such as large loss,high cost and unsatisfactory cooling effect.It is difficult to solve the heat damage problem in the local high temperature working place,especially in the coal mining face and the driving face.Therefore,it is an urgent need to study a cooling technology that is suitable for local high temperature working places in underground mines.In this paper,in view of the problems of local high temperature heat damage in mines,the thermal damage causes of the well face and the theoretical analysis of the main heat source and wet source are cut in.The theoretical analysis,mathematical calculation,numerical simulation and field test are combined to carry out the excavation work.The surface cooling technology is analyzed,combined with fluid thermodynamics,mine ventilation,heat transfer and other disciplines,aspen simulation,etc.,research on the cold load calculation of the mine,the circulation loop of the liquid carbon dioxide refrigeration process,and developed the cooling for the cooling of the heading face.device.The main content of the thesis research:(1)It Introduced some domestic and international research status on mine heat damage and refrigeration technology,and expounded the various hazards caused by deep well heat damage to underground workers and society,indicating the necessity and urgency of mine heat damage must be solved Sex.(2)Introducing the principle of liquid carbon dioxide refrigeration cycle system.Based on the four major systems of refrigeration cycle,heat exchanger,compressor,condenser and shut-off valve analyze the whole refrigeration cycle.The design of the cooling system for the driving face is carried out,and the basic theory of heat transfer is used to theoretically analyze the heat transfer calculation of the heat exchanger,and the calculation of the liquid carbon dioxide cooling system includes the calculation of the heat exchanger,the compressor and the condenser.(3)Using the simulation software aspen to simulate the whole liquid carbon dioxide cooling system,and establish a carbon dioxide refrigeration cycle system model,check the parameters of the heat exchanger,compressor and condenser calculated in the previous(4)calculation,and select the refrigeration cycle system.Type design and finalize the parameters.(5)Taking the drilling face of 31023 as an example,according to the actual heat damage problem,through the hot environment test of the roadway,several measuring points are arranged on the working face,and the temperature before and after the liquid carbon dioxide cooling system is measured.Based on the previous content,the Fluent numerical simulation is used to obtain the temperature distribution map of the roadway,and the temperature at the measuring point is recorded,and compared with the actual measured value.The liquid carbon dioxide cooling system can effectively dig the temperature of 31203 into the working surface.Reduce from 40? to below 25? to ensure a comfortable working environment.