Real-time monitoring method of coal mine shaft frozen wall temperature based on fiber Bragg grating sensing

Abstract

The present invention discloses a method for real-time monitoring of the frozen wall temperature of a coal mine shaft based on fiber grating sensing. A seamless steel pipe is used as the sensor carrier of the fiber grating sensor. Frozen holes are used as measuring points to lay out fiber grating sensing devices and connect them in series with the increase of drilling depth. The grating fiber demodulation equipment is connected to transmit the signal to the computer system to collect and process monitoring data, and to monitor the temperature of the frozen wall in real time. . The monitoring accuracy of the present invention is significantly better than traditional monitoring methods, reducing monitoring errors, avoiding and reducing possible wrong construction decisions; strong anti-interference ability, passive work, no power supply and no electrical signals and electronic devices, avoiding local temperature disturbances, It effectively avoids noise data and has good monitoring stability; it adopts computer technology and has high real-time performance, which can meet the requirements of different aspects and provide guidance for the construction of shaft shaft freezing method in coal mines.

Description

technical field [0001] The invention relates to the technical field of coal mine shaft construction monitoring, in particular to a method for real-time monitoring of the frozen wall temperature of a coal mine shaft based on optical fiber grating sensing. Background technique [0002] When the coal mine vertical shaft shaft is constructed in an unstable topsoil layer or isolating groundwater, special construction methods are generally adopted to pass smoothly. At present, the freezing method is widely used. The freezing method has a long history and is relatively mature in theory and practice. When the freezing method is used for construction, the excavation of the shaft of the coal mine shaft must be excavated at an appropriate time. When the frozen wall has formed but has not been frozen within the range of the shaft, the stability of the frozen wall is better, which is the best choice for the excavation time of the shaft. Otherwise, it may be unfavorable to the excavation...

AI Technical Summary

Problems solved by technology

However, in the current wellbore freezing construction, the method of arranging temperature measuring holes around the freezing holes and estimating the thickness of the frozen wall according to the monitored temperature of the temperature measuring holes has many disadvantages: 1. It can only reflect the local area of ​​the frozen wall The development situation, there are a lot of blind spots, which cannot reflect the development of the entire frozen wall; second, when the frozen wall has not yet formed an intersection circle, there will be a large error in judging the situation of the frozen wall through the data of the temperature measuring hole; third, currently using The traditional frozen wall temperature measurement equipment mainly includes copper-constantan thermocouple strings arranged in the temperature measurement hole, thermistor-type digital single-point thermometers, etc., which have disadvantages such as difficult maintenance technology, easy damage, and difficult online real-time monitoring.

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