Prevention and control of heat disaster in the hot

Prevention and control of heat disaster in coal mines

1 the air temperature of underground mining face and Electromechanical chamber should comply with the provisions of the current "coal mine safety regulations"

2 during the design of new, reconstructed and expanded mines, the identified temperature prediction method shall be adopted according to the geological report of mine exploration and the relevant data provided by the construction unit, and the mine temperature prediction meter shall take the same sample calculation under the specified state conditioning conditions, temperature, humidity and strain rate. Cooling measures shall be taken at the over temperature place

3 comprehensive cooling measures should be taken for mines with temperature exceeding the limit

4 adopt non-human refrigeration to comprehensively integrate producers and consumers. According to the specific conditions of the mine, comprehensive measures such as using natural cold sources, increasing the air supply or increasing the local wind speed at the concentration of operators, downward ventilation or co flow ventilation, which are conducive to cooling, avoiding underground heat sources, isolating or reducing heat sources to the inlet air for heat dissipation, draining or blocking hot water, personal protection, etc. should be taken

5 using artificial cooling should be based on the geological conditions of the mine, development and mining system, roadway layout, mine ventilation system, cooling and cooling range, mining depth, cooling load, mine water inflow and water quality and temperature, return air volume and temperature, degree of mining mechanization, heat source and experience of Mines with similar conditions. After technical and economic demonstration, local cooling measures such as underground mobile air conditioning or compressed air cooling should be selected Ground centralized air conditioning system, ground and underground combined air conditioning system and other cooling methods

6 underground air treatment shall comply with the following provisions:

(1) underground air treatment equipment and facilities shall comprehensively adopt direct evaporation type, water-cooled surface type, spray cooler or spray chamber according to the air conditioning system and the amount of air to be treated, cooling load, etc

(2) underground air treatment can be centralized or treated separately at each cooling location

(3) when the amount of air to be treated is large, the cooling load is large, or the temperature difference of natural air in long and narrow space is greater than 10 ℃, it is difficult to achieve the effect or uneconomical to use a single air treatment equipment or facilities, it is appropriate to adopt a comprehensive air treatment method

(4) the treatment air volume of air treatment equipment should be determined according to the cooling load and air supply temperature difference, but it should not be greater than the air volume at the roadway where 2024-T3 alloy is successfully developed later. For the heading face, the treatment air volume shall not exceed 70% of the air volume supplied by the full negative pressure of the face

7 the condensate heat removal method of the refrigerator should be determined according to the cooling method, condensation heat, water quality and quantity of water source, water temperature, mine return air volume and temperature, mining depth and other factors, and should comply with the following provisions:

(1) when the condensation heat is removed from the ground, the cooling tower or natural water body can be used

(2) when the cooling mode of underground centralized air conditioning system is adopted, if the water quality, quantity and temperature of the well water are appropriate or treated appropriately, the well water should be preferentially used to remove the condensation heat; When the underground water is not applicable, the technical and economic comparison shall be carried out to determine the discharge methods, such as removing the condensation heat from the mine return air and discharging the condenser circulating cooling water to the ground for cooling treatment

(3) when using return air to remove condensation heat underground, the wet bulb temperature of return air flow should not be higher than 29 ℃

8 the selection of refrigerant should meet the requirements of fire prevention, non explosion, accounting for 95% of the world's total production and sales, non-toxic, high condensation temperature, low condensation pressure, low price, environmental protection, etc

9 the standby coefficient of the cooling load of the refrigerator can be taken as 110 ~ 120, and the number of refrigeration equipment should not be less than 2. When the cooling load is large, large refrigerator should be selected

10 when the refrigeration station is set on the ground, the design and layout of the refrigeration room should comply with the relevant provisions of the current national standard code for design of heating ventilation and air conditioning (GB 50019). The distance between the refrigerating machine room and the air intake wellhead should not be less than 50m, and it is below the dominant wind direction in summer

11 when the refrigeration station is located underground, the location and layout of the refrigeration chamber should be conducive to cooling and the removal of condensation heat, and meet the requirements of equipment handling, installation, maintenance, operation and safety

12 when the well depth is greater than 600m, the cooling capacity transmission of the ground central air conditioning system must have a coupling device. The selection of coupling mode should consider factors such as safety, energy saving, high efficiency and convenient maintenance and management. After technical and economic demonstration, shell and tube high and low pressure heat exchangers, water energy recovery devices, multi cavity hot pressure converters and other equipment should be selected

13 the water supply pipe of the cooling capacity transmission pipe should be insulated. Whether the return pipe is insulated shall be determined according to the ambient temperature where the return pipe is located. The transmission of cooling capacity shall comply with the following provisions:

(1) the thermal insulation material and structure of the pipeline shall be fireproof, moisture-proof, gas-proof and non-toxic, so as to avoid the generation of cold bridges, and the temperature rise shall not be higher than 06 ℃/1000M

(2) the pipeline can be laid in the form of wall hanging, overhead or trench, and the cold transmission pipe should not be arranged in the return air lane

(3) low temperature refrigerant should use calcium chloride solution, glycol solution or glycerol solution according to the source of raw materials, corrosivity, water solubility, refrigerant temperature and price, and the concentration of the solution should be determined according to the refrigerant temperature

14 the pipes of the cooling system and cooling water system in the mine refrigeration system should be calculated for hydraulic balance. The design of hydraulic system shall comply with the relevant provisions of the current national standards code for design of building water supply and drainage GB 50015 and code for design of heating, ventilation and air conditioning GB 50019