Laser-Doppler-effect-based feed depth measuring system for drilling rod of coal mine gas drilling machine

Abstract

The invention relates to a laser-Doppler-effect-based feed depth measuring system for a drilling rod of a coal mine gas drilling machine. The laser-Doppler-effect-based feed depth measuring system comprises an optical path module, a frequency shift detection processing module, a component connecting module and a coal rock fixing module. The optical path module is packaged in a cylindrical outer case and is arranged at the outer side of the system. The frequency shift detection processing module is packaged in the cylindrical outer case and is aligned at a drilling rod surface. The component connecting module is connected to the optical path module outer case and the frequency shift detection processing module outer case. The coal rock fixing module is connected with the optical path moduleouter case and is suspended and fixed right above the coal rock outer end the drilling rod. For the drilling rod withdrawing process, scattered light generated by laser irradiation on a moving drilling rod is collected based on laser Doppler effect, a Doppler frequency shift of the laser is measured, and the real-time length of the drilling rod is calculated. The withdrawing length of the drilling rod is equivalent to the feeding depth of the drilling rod, so that the interference of factors like downhole complex illumination, irregular work, water flows, and dust is avoided; the reliabilityand accuracy of the measurement are improved; and the safety of coal mining is guaranteed.

Description

technical field [0001] The invention relates to the technical field of coal mine equipment detection, in particular to a coal mine gas drilling rig drill pipe feed depth measurement system based on the laser Doppler effect. 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. Whether the borehole reaches the specified depth is related to the effect of gas drainage and the safety of coal min...

AI Technical Summary

Problems solved by technology

[0005] In order to solve the deficiencies in the prior art, the object of the present invention is to provide a coal mine gas drilling rig drill pipe feed depth measurement system based on the laser Doppler effect, which mainly uses the principle of laser Doppler interference to collect laser radiation to the moving drill pipe The scattered light generated on the surface avoids the influence of complex lighting downhole; by measuring the Doppler frequency shift of the laser, the real-time speed during the extraction process of the drill pipe is automatically measured, and after data processing such as integration, the real-time length of the extracted drill pipe is calculated. , to avoid the impact of irregular operations; to measure the process of coal mine gas drilling rig exiting the drill pipe, the exit length of the drill pipe is equivalent to the depth of the drill pipe feed, avoiding the impact of harsh environments such as water flow and dust on the system during drilling; Real-time contact measurement based on laser Doppler effect avoids interference caused by other factors, improves measurement reliability and accuracy, eliminates misreporting and misreporting depth caused by external and human factors, and ensures coal mining safety

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