Model of underground gasification furnace and furnace building and gasification method

Abstract

The invention discloses a model of an underground gasification furnace and a furnace building and gasification method. The model of the gasification furnace comprises a plurality of gasification unitfurnaces, the gasification unit furnace comprises three gas outlet wells, and the three gas outlet wells extend downwards to the coal seam of a mine area; the three gas outlet wells are arranged in atriangle, and two gas inlet wells are arranged outside the two gas outlet wells at the bottom end of the triangle. The two gas inlet gas wells are connected with the two gas outlet wells to form two gasification channels at the outer side of the bottom end of the triangle. A gas inlet well is arranged outside the gas outlet well at the top end of the triangle, and the one gas inlet well is connected with the gas outlet wells at the top of the triangle to form a gasification channel outside the top end of the triangle. The gas outlet gas wells at the top end of the triangle are respectively communicated with the two gas outlet gas wells at the bottom end of the triangle; according to the invention, the pass-through connection of the plurality of unit gasification furnaces is achieved without using a high-pressure pass-through mode, and the problems that the production period is long and the gasification furnace unstably operates during the connection process.

Description

technical field [0001] The invention relates to an underground gasification furnace type and a furnace construction and gasification method. Background technique [0002] Underground coal gasification is mainly divided into four steps, namely furnace building, ignition, gasification, and furnace shutdown. The construction of the gasifier is an important basis for realizing the rapid start-up, rapid production and long-term stable operation of the gasifier. At present, the underground coal gasifiers used at home and abroad are all evolved from the gasification unit based on the CRIP process, which is characterized by a gas injection well for injecting gasification agent and a production well for recovering the generated coal gas ; The injection well is generally a directional horizontal drilling; the gasification process mainly occurs in the channel of the horizontal drilling. The disadvantage of this gasification unit is that if large-scale production is carried out, multi...

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Problems solved by technology

The main reason for the above problems is the problem of high-pressure penetration: in order to prevent the problem of ignition failure caused by too much water in multiple directional hole channels in the existing furnace type, when a gasifier is constructed, the gasification units are not completely connected after being combined. , there is a certain length of coal seam in the middle for partition to prevent coal seam water from pooling together

Therefore, it is necessary to penetrate the partitioned coal seam with high pressure after ignition, which will easily cause damage to the roof and floor of the coal seam, and problems such as gas loss in the gasifier and groundwater ingress will occur, which will affect the stability of gasification operation.

[0004] In addition, there are also the problems of long production period and unstable gas production; the long production period means that the system needs multiple gasification units to operate at the same time to reach the designed production capacity, and the existing furnace type requires a single gasification unit to be started separately , the start-up time is long, leading to the problem of long production cycle

[0005] The instability of gas production is due to the continuous gasification of gasifiers, which means that after the operation of a gasifier is completed, the next gasifier must go through the process of fracturing and ignition. , will inevitably lead to instability due to gas composition and gas volume

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