PREDICTION OF HEATFLOW FROM SURROUNDING ROCK INTO MINE AIRWAYS - A FINITE-ELEMENT STUDY

This paper reports the results of a finite element study of the geothe rmal heatflow into dry mine airways. For isotropic and unsteady state conditions the heatflow into mine airways is studied for a range of su rface heat transfer coefficients between rock and air, and age of the airway. Dimensionless temperature gradient values are presented in tab les for different values Of Boit and Fourier numbers and the results a re compared with Starfield tables and Gibson algorithm. It is found th at Starfield tables have consistently over-predicted the G values with errors ranging from 2% to 10%. The differences between results obtain ed from the finite element study and the G values calculated from Gibs on's approximation method are mapped. The small error values over a la rge range of Fourier and Biot numbers confirm the suitability of Gibso n's algorithm to rapidly calculate G values for estimating the heat tr ansfer from surrounding rock to mine air.