Volume modeling method for coal bed underground combustion space areas

Abstract

The invention discloses a volume modeling method for coal bed underground combustion space areas. The volume modeling method includes: deducing temperature field control equation under the action of seepage by analyzing affection mechanisms from the seepage to the temperature fields on the basis of high temperature of the coal bed underground space areas and relative constant temperature of normal underground temperature fields according to the thermal conduction basic theory,; introducing Bessel function to deduce peripheral temperature field distribution equation of combustion passages, introducing finite element values to solve, inverting the distribution of the temperature fields under the action of seepage through finite element value software by the aid of field temperature detection data, and determining high-temperature affection boundary of the combustion passages; acquiring the coal bed temperature distribution matched with the field detection best by adjusting section size of the combustion space areas, inverting the shape and the size of the coal bed underground combustion space areas, and computing approximate volume of the combustion space areas. The volume modeling method for the coal bed underground combustion space areas is capable of determining the shape and the size of the coal bed underground combustion passages more accurately, and thermal source models of the combustion space areas of the combustion passages, which are provided by the volume modeling method, have a certain practical value when the volume modeling method is compared with other computing methods.

Description

technical field [0001] The invention belongs to the field of geological engineering, and in particular relates to a method for determining the shape and size of a stratum cavity area after coal seam combustion, and further determining the volume of the burn-out area. Background technique [0002] Underground combustion of coal seams is one of the research directions of coal mining in the world, and it is an important way to fundamentally solve a series of technical and environmental problems existing in traditional mining methods. In actual operation, due to the deep burial of the burn-up area and the complexity of geological conditions, it is difficult to accurately calculate the shape and size of the underground coal-burning area only relying on existing geological survey methods. Therefore, there is currently no effective method to calculate the volume of the underground burn-up zone, so as to solve such problems as how to further increase the combustion calorific value, ...

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Problems solved by technology

In addition, changes in the permeability coefficient and seepage velocity cause changes in the heat exchanged between the rock mass and the water flow, and also affect the distribution of the temperature field of the rock mass.

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