Research on Periodically Change of Airflow Temperature in Mine

Airflow temperature in mine changes with periodical change of surface air temperature, but its change pattern couldn't be expressed by quantitative calculation currently. by differential equation of round roadway and zero dimension of boundary condition, wall rock thermal field is expressed by superposition of two thermal fields; the two thermal fields is respectively effected by annual average wind temperature and air temperature fluctuation. The paper mainly analyses wind temperature fluctuation differential equation and its definite condition; and deduces the expression of temperature fluctuation amplitude and phasing degree at different point of roadway, while surface air temperature periodically fluctuating; by calculating and analyzing, we have the conclusion that amplitude of temperature fluctuation presents downtrend of negative exponent curve with roadway length increasing; phasing degree linearly lag with roadway length increasing. The research result is greatly significant for controlling thermal damage and forecasting wind temperature for seasonal hot mine.