Alpine Region Msw Landfill Gas Migration Law

This paper introduced the brief status of alpine region of our country on basis of literatures about landfill gas home and abroad. The research of landfill gas migration condition of the alpine region has important projects and also the social meaning. This article unified research content of crosswise scientific research topic, "Qiqihar City life Trash Management and Processing", chosen the the Qiqihar city landfill as the object and proposed the main research content of this topic. The research work can hopefully provide the technical basis for the operational guidance of Qiqihar city landfill and the collection use of landfill gas as reference for the landfill of other alpine region city.In the article, theory model and the relevant control equations of porous media rubbish migration in gas of life landfill were established. Considering the effects of the solution method, consideration of the penetration rates, porosity, pore rate and temperature, combining with the actual situation of Qiqihar city numerical simulation, we get the main conclusions as follows:(1) The Qiqihar home scrap's ingredient composition changes with the different inhabited area, however, the proportion of food residues is very high and has a good degradability. The gas production rate of 103.46L3/kg was obtained by the sample element analysis and industry analysis of typical of the city's garbage.(2) Qiqihar city under the weather from 1971 to 2000 statistics shows that the annual average temperature of 2.3℃, extreme maximum temperature of 41.6℃, extreme minimum temperature of-42.2℃, frozen for an average of 195 days. The maximum depth of the frozen layer is 4.8m in Qiqihar city. The temperature can significantly affects landfill gas thickness of solid waste landfill, and affects the landfill gas production rate. According to calculation, the city's garbage landfill waste body mass source term is (1.0～2.7)×10-7kg/(m3·s).(3) The results of the numerical simulation of domestic rubbish landfill in Qiqihar show that:on the isotropy and anisotropy permeability coefficient conditions, the pressure and the flow field of the rubbish is different. As the landfill rubbish is anisotropy, the value of Kh/Kv changes from 3.0 to 37.5. The pressure increases gradually at the depth direction in the landfill, the most change of the pressure is 7683.1 Pa. There are some differences in the calculated pressure as the rubbish is isotropy, the difference between the isotropy and anisotropy rubbish is 501.2Pa.(4) Without changing the gas production rate, change the garbage's porosity from 0.67 to 0.50, the pressure of the landfill changes not obviously, the maximum change is 56.1 Pa. As the gas production rate decreases, the pressure of the same depth is also reduced. The smaller the gas production rate, the pressure changes in the landfill is smaller. When the gas production rate changes from 1.0×10-7kg/(m3·s) to 2.7×10-7kg/(m3·s), the maximum pressure change is 732Pa.(5) The outside temperature will affect the temperature of the cover and the garbage body, which cause the temperature dropped and the garbage body is divided into landfill gas and no gas in two parts. When the gas production rate and the garbage's porosity are constant, changes the thickness of the freezing level from 1.0m to 4.8m, the pressure of the landfill decreases, the maximum change is 65.8Pa.When the thickness of freezing layer and the garbage's porosity are constant, changes the gas production rate from 1.0×10-7kg/(m3·s) to 2.7×10-7kg/(m3·s), the pressure of landfill increase gradually, the maximum change is 674.9Pa. (6) When the thickness of freezing layer and gas production rate are constant, we change the garbage's porosity from 0.67 to 0.50, the pressure of the landfill changes not obviously, the maximum change is 37.9Pa. When we use the largest gas production rate we get the flow rate is 0.762m3/s; the corresponding hierarchical case, the flow rate is 0.683m3/s.(7) When we design landfill gas collection system of the alpine region, we should consider the temperature effect to strength and security of the pipe, to avoid gas gathering pipeline leaks and damage in the low temperature, to ensure the safety and reliability of gas gathering system.The results not only provide a reliable basis for the Qiqihar city landfill gas collection and management, but also provide reference for other alpine region of solid waste sanitary landfill operation and management.