NO2-absorption-characteristic-based drill rod feeding depth measuring system of coal gas drilling machine

Abstract

The invention relates to a NO2-absorption-characteristic-based drill rod feeding depth measuring system of a coal gas drilling machine. The system comprises a hole sealing module and a cavity ring-down NO2 concentration module. The hole sealing module includes a flat sealing plate, an annular sealing O ring, a small ventilating hole, a ring-down cavity leather hose connecting end, a sample gas leather hose connecting end, and a coal rock fixing member and the like and is used for sealing gas in a drilled hole and controlling inlet or outlet of NO2 gas. The cavity ring-down NO2 concentration module is used for measuring the diluted NO2 concentration. A high-oncentration NO2 sample gas, a flow control valve and a sample gas solenoid valve are used for inputting quantitative high concentration NO2 into the hole; an intake solenoid valve, a filter membrane, an inlet end and an outlet end are used for providing gas in the hole for the cavity. The system belongs to the field of the post-drilling measurement technique. With the cavity ring-down technique, the diluted NO2 concentration in the hole is measured and thus the depth of the hole is deduced, so that the influences of the complicated underground environment and collapsed hole are eliminated and the measurement accuracy is improved.

Description

technical field [0001] The invention relates to the technical field of coal mine detection, in particular to a coal mine gas drilling rig drill pipe feed depth measurement system based on NO2 absorption characteristics. Background technique [0002] Coal mine gas is an important factor related to coal mine safety, and gas outburst can easily cause mine accidents. For this reason, the National Coal Mine Safety Supervision Bureau summarized and put forward the policy of "exhausting first, then mining, monitoring and monitoring, and determining production by wind". Gas extraction has become a prerequisite for coal mining. At present, for gas extraction, the coal mine gas drilling rig is used to drive a certain length of drill pipe into the coal seam, and then pull out the drill pipe after reaching a specified depth, thereby forming a hole for gas extraction. The methane-dominated coalbed methane will expel the high concentration of methane through pores, accompanied by a small...

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Problems solved by technology

[0004] In order to solve the deficiencies of the prior art, the object of the present invention is to provide a coal mine gas drilling rig drill rod feed depth measurement system based on NO2 absorption characteristics, which belongs to the post-drilling measurement technology, and uses cavity ring-down technology to measure the diluted NO2 in the hole. NO2 concentration, and then calculate the depth of the hole, avoiding the influence of complex underground environment and hole collapse, improving measurement accuracy, eliminating misreporting and misreporting depth caused by external and human factors, and ensuring the safety of coal mining

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