Mine climate of mine air

Mine climate: the comprehensive effect of temperature, humidity and flow of mine air. These three parameters are also called the three elements of mine climate conditions.

Cooling and heating of mine air

With the continuous improvement of mining concentration and mechanization, the underground heat damage is becoming more and more serious, so air cooling measures must be taken.

In the cold winter mining area in the north, heating measures must be taken to prevent the shaft from freezing and causing accidents in shaft lifting and transportation.

Influence of microclimate on human thermal regulation. 1. temperature: temperature plays a major role in human thermal regulation; 2. Humidity: high humidity makes it difficult for sweat to evaporate and dissipate heat, which easily leads to the destruction of human thermal balance. 3. Wind speed: When the temperature is lower than the human body, the higher the wind speed, the more heat dissipation. When the temperature is higher than the human body, the human body gains convective heat. 4. Radiation: It is the surface temperature of the objects around the human body that affects the radiation heat dissipation of the human body. When the surface temperature of the surrounding objects is higher than that of the human body, the human body gains radiant heat.

The influence of microclimate on human body heat dissipation The main influencing factors of heat dissipation mode are convection heat dissipation, air temperature, wind speed, radiation heat dissipation, surface temperature of objects around human body, evaporation heat dissipation, air relative temperature, wind speed and factors affecting underground temperature.

The main factors affecting the change of underground temperature are: 1. Mine inlet air temperature; 2. Compression and expansion of underground airflow. 3. Heat dissipation of mechanical and electrical equipment. 4. Exothermic oxidation; 5. The human body emits heat and moisture; 6. Underground hot water for heat dissipation. 7. Heat exchange between surrounding rock and underground air.

Cataract Degree Adapted to Different Jobs: Dry Cataract Degree Comfortable Rest Degree Warm Cataract Degree Sitting Work 6 18 Medium Labor 8 25 Heavy Labor 10 30 Influence of Mine Climate on Human Thermal Balance

Metabolism is one of the basic processes of human life activities. The heat dissipation of human body is mainly carried out in three basic forms: convection between the surface of human skin and the outside world, radiation and sweat evaporation.

Convective heat dissipation depends on the temperature and flow rate of the surrounding air;

Radiation heat dissipation mainly depends on the ambient temperature;

Evaporation heat dissipation depends on the relative humidity and flow rate of the surrounding air.

Human thermal balance relationship:

qm-qw=qd+qz+qf+qch

QM-The heat generated by human body in metabolism depends on the amount of human activity;

QW-the heat consumed by human body in doing work, and the excess heat discharged by qm-qw human body;

Qd-the heat emitted by human body, which is negative below the surface temperature of human body; Otherwise it is positive;

Qz-the heat brought by sweat evaporation or exhaled water vapor;

Qf-radiation heat dissipation between human body and surrounding objects, which can be positive or negative;

QCH—— The human body is converted from heat, and it does not expel energy from the body; When the human body is in thermal equilibrium, QCH = 0；;

When the external environment affects the thermal balance of human body, the human body temperature increases QCH >: 0, and the human body temperature decreases QCH.

The three factors of mine climatic conditions are the main factors affecting human thermal balance.

Temperature: It plays a major role in human convection heat dissipation.

Relative humidity: it affects the effect of evaporation and heat dissipation of human body.

Wind speed: it affects the effect of convection heat dissipation and evaporation heat dissipation. The intensity of convective heat transfer increases with the increase of wind speed. At the same time, the effect of water exchange also increases with the increase of wind speed. In windy weather, cool clothes dry quickly.

Indicators for measuring mine climate conditions

1. Dry-bulb temperature Dry-bulb temperature is one of the indicators for evaluating mine climate conditions in China at present. Features: To a certain extent, it directly reflects the quality of mine climate conditions. The index is simple and easy to use. However, this index only reflects the influence of temperature on mine climate conditions, but does not reflect the comprehensive influence of climate conditions on human thermal balance.

2. Wet bulb temperature Wet bulb temperature can reflect the influence of air temperature and relative humidity on human thermal balance, which is more reasonable than dry bulb temperature. However, this index still cannot reflect the influence of wind speed on human thermal balance. 3. Equivalent temperature Equivalent temperature is defined as the ratio of enthalpy to specific heat of wet air. It is an index based on energy to evaluate the climatic conditions of mines.

4. Empathy temperature Empathy temperature (also called effective temperature) was put forward by American Society of Heating Engineers in 1923. This index is a calculation chart of empathy temperature based on the feelings of the subjects to the environment through experiments.

5.Katadukatadu is 19 16, which was put forward by L Hill and others in Britain. The degree of cataract was measured by cataract vision instrument. Catastrophe degree can be divided into dry catarrh degree and wet catarrh degree, which reflects the influence of temperature and wind speed on climate conditions, but does not reflect the influence of air humidity. In order to measure the comprehensive effect of temperature, humidity and wind speed, K D = 465,438+0.868 f/tw/m wet catarrh (Kw) is measured when a layer of wet gauze is wrapped on the catarrh storage ball, and the actual measurement and calculation methods are exactly the same as those of dry catarrh.

Safety standard for mine climatic conditions

At present, the dry bulb temperature is the index to evaluate the mine climate conditions in China. Article 53 of Mine Safety Regulations issued by the State Council 1982 stipulates that the maximum allowable dry-bulb temperature of mine air is 28℃.

The fresh air on the ground and the harmful gases and floating dust generated underground are the floors.

Fresh air: the air slightly polluted in the air intake roadway before the air is used in the mine roadway.

Dirty air: after passing through the air-using place, the air in the return air roadway is heavily polluted.

Common harmful gases in mine air: Co, NO2, SO2, NH3 and H2.