Numerical Early Warning Model Research of Landfill Gas Permeation and Diffusion Considering Flow-Temperature Coupling

Based on seepage mechanics in porous medium gas and heat transfer theory, numerical early warning model is established, which is on quantitative description of migration and release of landfill gas and penetration and diffusion of energy, and dynamic migration of landfill gas is also analyzed quantitatively. The results show that the gas pressure improved as the depth increased, and internal gas pressure in landfill maintained at 1~3 Kpa. The heat generated by the degradation of landfill gas is released, and its distribution range is between 10 m and 15 m, and it is also effected by biodegradation of waste and distribution of gas. The temperature is changed dramatically at the middle of landfill, which is in accordance with distribution law of gas pressure and temperature in the field monitoring. The numerical results which are reliable and practical are verified. It can provide technical support on the control of potential environmental pollution caused by landfill gas, the design of landfill gas collection system and development of gas resource.