Analysis of Major Factors Influencing Heat Accumulating Process of Loose Coal in Mine

摘要

Coal self-ignite is one of primary calamity of underground mine. It has threatened severely selfignite production safety of mine, and hinders development According to the theory of thermodynamics and heat transfer, the heat accumulating process of loose coal self-ignite is analyzed, and the equation of heat transfer is deduced, and the requirement of coal temperature raised during coal self-ignite is known. The major effect factors of heat accumulating have temperature, void-age, float coal thickness, ianeway airflow and air leak intensity. The higher temperature is the bigger heat liberation intensity is, the bigger temperature difference between coal and rock of surround is; it is more disadvantages for heat accumulating of coal. The float coal thickness is material basis of heat production and thermal storage, as it is bigger than the least float coal thickness, coal self-ignite is possible. The voidage determines air leak intensity and thermal conductivity. The air leak intensity affects both heat liberation intensity and convection heat elimination. Coal self-ignite is possible as air leak intensity is less than upper limit air leak intensity and bigger than the minimum value, which it can offer enough oxygen concentration. The result can perfect the theory of coal self-ignite in low temperature, and it can promote development of coal self-ignite control technology.