Thermal Conductivity Simulation Test Of Porous Media And The Research On Heat Transfer Characteristics

Based on the theory of heat transfer in porous media, the use of different size ball to simulate the heat transfer in porous media material tests, by controlling the particle size and number of balls to change the pore structure of the porous medium. Designed heat transfer simulation in porous media under five different porosity conditions, to analyze porosity and specific surface area of the porous media influence thermal conductivity equivalent, using the equivalent resistance method to establish the binary heat transfer model, and then use flac3D underground roadway temperature distribution was simulated.Bring about changes in the porosity of the porous medium specific surface area of difference, by analyzing the effective thermal conductivity and porosity, surface area than the relationship between the effective thermal conductivity results show that with the increase in porosity and non-linear increase in the same surface area, After and porosity tends to a certain value, the closer the effective thermal conductivity. Equivalent thermal conductivity ratio increases with the surface area increases nonlinearly at the same porosity, but changed slightly when the porosity is closer to the thermal conductivity also relatively close. This method generated porous medium surface area, porosity and effective thermal conductivity value of prediction models have been well verified the validity of all further illustrate the match between the two, which later engineering studies guiding significance.Based on the heat transfer theory and Fourier's law of thermal conductivity, heat transfer experiments in porous media combine analog construct binary porous media heat transfer model to calculate the effective thermal conductivity to obtain effective thermal conductivity of porous media computing experience equation. The experimental results compared with the calculated values, calculated values and actual values match. A comprehensive analysis of porous media with different porosity and thermal conductivity than the equivalent changes in the conditions of lower surface area, surface area is small in porosity effect on thermal conductivity evident in the surface area of the larger porosity significant impact on thermal conductivity, when After more than a certain value equivalent thermal conductivity stabilized. By analyzing the porosity and surface area ratio on the effective thermal conductivity, gives the functional relationship between them expression.Roadway at different depths, rock porosity decreases with increasing depth, resulting in increased thermal conductivity, thermal conductivity increases with temperature diffusion significantly faster, and the temperature field of roadway surrounding area presented symmetry in the absence of seepage Distribution. Each detection point is obvious similarity laws, temperature increases non-linearly with time, and gradually reduce the rate of increase, when it reaches a certain value, temperature stabilized.Heat transfer simulations in porous media and use flac3D simulate the process, did not consider the underground seepage of fluid flow and temperature distribution, and this part of the study has yet to be deepened.