| As an important energy source in China,coal plays a vital role in the rapid development of the national economy.In recent years,as the intensity of coal mining has increased and the level of mechanization has increased,the depth of coal mining has increased year by year.As a result,the number of high-temperature heat-damaged mines has increased year by year,and the problem of deep-hole heat damage has become more and more prominent,seriously affecting the efficient and safe production of coal mines.In the face of high temperature and heat damage in mining face,in recent decades,domestic and foreign scholars have done a lot of research on the formation mechanism of high temperature heat damage in mines and the technology of heat damage control.Different mines with different geological conditions and different degrees of heat damage have adopted different The cooling measures(including non-mechanical cooling and mechanical cooling)have good cooling effect in the early stage,and the thermal environment of the mining face has also been improved.But in the later stages of system operation,there are also many problems that need to be overcome.For example,the air carrying capacity is small,the cooling capacity of the refrigeration equipment is insufficient,the cold loss is serious,the heat exchange efficiency of the air cooler is low,and the cooling distribution of the working surface is uneven.In this thesis,in view of the high temperature heat damage existing in the coal mining face of the mine,firstly,according to the different heat sources of the working face,the heat dissipation of the working surface is calculated.The wind flow of the working face and the surrounding rock of the roadway and the thermal and wet exchange of the coal wall are analyzed.Taking a coal mining face as an example,the heat source analysis method,the airflow balance method and the enthalpy difference method are used to calculate the cooling load of the coal mining face to meet the cooling requirements.,a comparative analysis of their respective characteristics.According to the law of conservation of energy,given the thermodynamic parameters of wind flow and the parameters of surrounding rock roadway,established a differential equation for wind temperature and working surface length.The similar roadway model of coal mining face was established.The Fanning plate of ANSYS simulation software was used to simulate the variation of wind flow velocity field and temperature field of coal mining face and analyze it.Secondly,according to the distribution of workers at the working face,the concept of effective air-cooling space is proposed and the corresponding local cooling load is calculated.Aiming at the lack of overall cooling in the existing cooling mode,a new sub-zone cooling technology is proposed.The main air cooler of the inlet air duct is used to provide background airflow to the working surface,and the working surface wind temperature is 26? and 30? as the critical value.In the working surface wind temperature of 26??30?,the small air cooler is used to transport the cooling capacity;The working surface wind temperature is greater than 30?,and the atomization spray method is used to cool down.Determine the reasonable cooling range,quantity,air supply volume,air supply speed,and nozzle type,fog particle size,spray flow rate.After the sub-zone cooling system is put into the working face of a mine 401 1 05,the temperature of the dry-drying ball of the wind surface is measured on the site,and the technical effect of the cooling surface of the working face is verified,and the economic analysis is carried out.The results show that the cooling effect of the wind section cooling technology is good.In the local air cool ing space where workers work,the air temperature is maintained between 24? and 28? after cooling.Compared with the traditional cooling technology,the economic cost is lower.The performance ratio is higher,and it has certain practical significance and promotion value. |
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