Back analysis of geometry and physics parameters in burning area of coal field

Based on the symmetry characteristic,a 2-D heat conduction model was established,which was calculated with the finite difference method.The impermeable layer thickness and the thermal conductivity of the stratum were unknown parameters in the model.A back analysis model was established to determine the two parameters with the simplex method.It is to suppose a group of parameters firstly,and then put them into the forwards analysis heat exchange model to calculate the temperature data.Then contrast the on-the-spot survey temperature data and get the relative error.Based on the error,optimize the two parameters with the simplex method until the error reaches to the required value.Then on-the-spot survey data was closed to the data with the simulated proved by the back analysis method in the paper.The temperature field of the stratum was simulated with back analysis.