Coal mine gas extraction method

Abstract

The invention discloses a coal mine gas extraction method. The coal mine gas extraction method comprises the following steps that a gas source is divided into a high concentration gas source and a lowconcentration gas source, the gas concentration in the high concentration gas source is larger than or equal to 25%, and the gas concentration in the low concentration gas source is less than 25%; ahigh concentration gas extraction system is used for extracting the high concentration gas source, and when the gas concentration is less than 25%, extraction parameters are adjusted to increase the gas concentration; when the gas concentration cannot be increased to be larger than or equal to 25%, a low concentration gas extraction system is used for extracting, the low concentration gas extraction system is adopted to extract the low concentration gas source and the high concentration gas source which does not meet the high concentration gas extraction conditions; and meanwhile, an air distribution system is started to dilute the gas concentration to be less than 3%. According to the coal mine gas extraction method, the purpose is to provide the coal mine gas extraction method, the gas concentration serves as the central control parameters, the high concentration extraction system and the low concentration extraction system are adopted to replace a traditional high negative pressureextraction system and a traditional low negative pressure extraction system, the extraction gas concentration is avoided being located in an explosion zone, and the intrinsic safety of the gas extraction in coal mine is realized.

Description

technical field [0001] The invention relates to the field of coal mines, in particular to a method for extracting coal mine gas. Background technique [0002] At present, the relatively serious situation of coal mine gas disaster accidents in my country has not been changed, and major gas accidents are not uncommon, and vigorously promoting coal seam gas drainage is an effective measure and method to reduce the burden of mine ventilation and dilute gas, make up for its shortcomings, and prevent major gas accidents ; In addition, mine gas is also a resource, and the extracted gas can be used to "turn harm into treasure" and reduce pollution to the atmospheric environment. [0003] Such as figure 1 As shown, gas is a kind of explosive gas, and the concentration range of gas in the air that can cause an explosion after meeting fire is 5% to 16%; when the gas concentration is 9.5%, its explosive power is the greatest (oxygen and gas complete reaction); when the gas concentratio...

AI Technical Summary

Problems solved by technology

Due to the complex and changeable drainage conditions, it is not easy to manage and achieve the effect with the same set of pipelines. In order to ensure the safety of coal mine production and improve the drainage effect, China's coal mine gas drainage system often has two or more sets. Drainage systems, such as high negative pressure system and low negative pressure system, the high negative pressure system is used to drain the coal seam drilling gas and cross-bed drilling gas in the original rock zone, and the low negative pressure system is used to drain coal mining work Gas buried in pipes at corners of the surface, gas in goafs in high-level boreholes, and gas pumped in roadways; however, the requirements for negative pressure in the drainage conditions of each system vary greatly. For gas drainage with high negative pressure, due to coal (rock) Due to the difference between layer overlay and gas occurrence, as well as the impact between gas drainage and coal seam mining, the requirements for negative pressure are also different, such as gas pre-extraction and extraction while digging (or extraction while mining). The pressure difference is relatively large; for low negative pressure gas drainage, the negative pressure of gas drainage in different locations such as the upper corner and the top drainage roadway (bottom drainage roadway) also has a large difference. In actual coal mine applications, the two systems require The negative pressure is very unstable, and there is no strict negative pressure limit; the construction of these two systems is mainly based on the need to reduce the impact of gas gushing on coal mine safety production, without considering the problem from the safety point of view of the gas drainage system, and there is no Define the most important indicator of drainage - gas concentration. Both systems generally have drainage conditions in the explosive range of gas concentration. The pipeline of the drainage system may be filled with gas whose concentration is within the explosive range; gas filled with explosive gas The pipeline system is a major source of danger that threatens the safety of coal mines. Pipeline gas explosion accidents have occurred in China and other countries

In addition, the drainage of such a partial pressure system is not conducive to increasing the gas drainage concentration and reducing the drainage effect

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