Characteristics of coal and rock thermal properties in Yongchuan mine

Coal and rock thermal physical parameters are basic data for mine cooling fire prevention and control Coal and rock density, specific heat, heat conductivity coefficient, thermal diffusivity, original temperature, temperature gradient in present mining area of Yongchuan coal mine were measured through in situ underground measurement and laboratory tests. Results of the tests show that:at the level -400 m of coal mine, the density, specific heat, coefficient of thermal conductivity and thermal diffusivity of coal samples are within the normal range; at the level -357 m to -438 m, the thermophysical parameters, such as the coal density, specific heat, coefficient of thermal conductivity, do not change with the elevation, at the level -400 m, the original temperature of coal and rock is about 35~36℃; below the zone of constant temperature in the mine, the geothermal gradient is 2.32/100 m above℃ the level -400 m and 2.65/100 m below℃ the level -400 m, tends to increase slightly, but still in the range of the normal geothermal gradient. Incombination with the geological exploration data, the measured value of the original temperature of coal and rock is smaller than the theoretically calculated value, but the error is not more than 3%, so the precision meets the demands of engineering.