Abstract: The present invention discloses systems and methods of measuring environmental information in a mine tunnel. The system may comprise an ultrasonic anemometer, a multi-parameter monitor, a data acquisition module, a central control platform, a data communication module, a flexible manipulator, a power conversion module, a display and alarm module, and a computer. The multi-parameter monitor may comprise at least one of an infrared detector, a CH4 detector, a CO gas sensor, an O2 gas sensor, a CO2 gas sensor, and a temperature and humidity sensor. The system may also measure the airflow in large sections of a mine tunnel through the flexible manipulator. The method may be able to remote measure the underground environment and airflow during normal production of the mine, which helps improve the abilities of mine disaster response and relief while ensuring the safety of emergency rescue personnel.

Abstract: A method for producing metal aluminum by molten salt electrolysis of aluminum oxide is provided. The method for producing metal aluminum by molten salt electrolysis of aluminum oxide uses an electrolytic cell. The electrolytic cell is divided into an anode chamber and a cathode chamber, and is filled with melts such as anolyte, catholyte and an alloy medium. The electrolytic cell is powered on to operate and an aluminum oxide raw material is added to the anode chamber to obtain high-purity metal aluminum in the cathode chamber. The disclosure provides an aluminum electrolysis method having the advantages of strong electrolysis operation adaptability, large selectivity of electrolysis materials and raw materials, being energy saving and environmentally friendly, and being capable of directly producing refined aluminum or high-purity aluminum.

Abstract: The present disclosure includes a method of testing for gas and temperature distribution in a goaf, wherein the test device comprises a cable coupled to a cable dragging machine, the cable including a test end configured to be buried in the goaf; a gas temperature tester configured to test a gas for composition and temperature; and a gas pump configured to continuously pump gas from the test end and transmit it to the gas temperature tester. In some examples, the method comprises placing the test end of the cable in the goaf. According to some examples, the method comprises starting the cable dragging machine and starting the gas pump simultaneously with starting the cable dragging machine. The method may comprise withdrawing the cable, via the cable dragging machine, at a constant speed and analyzing, via the gas temperature tester, the composition and temperature of the gas.

Abstract: The present disclosure includes a test device for gas and temperature distribution in a goaf, comprising a gas temperature tester configured to analyze gas detection signals and temperature detection signals. In some examples, the test device comprises a gas pump coupled to the gas temperature tester and a connector coupled to the gas pump at an end opposite the gas temperature tester. The test device may comprise a wire spool rotatably coupled to the connector and a cable configured to wind on the wire spool. According to some examples, the cable comprises a test end located on a first end of the wire spool and buried in the goaf. The cable may comprise an output end located on a second end of the wire spool, the second end opposite the first end.

Abstract: An on-line multi-component gas analysis system based on a spectral absorption technology includes a housing, wherein the housing includes an air inlet hole and an air outlet hole which are respectively connected with an air inlet pipe and an air outlet pipe, and the housing includes a dust removal and dehumidification device, a micro vacuum pump, an electronic flowmeter, and a plurality of different gas sensors; the dust removal and dehumidification device, which is configured to perform dust removal and dehumidification treatment on a gas entering from the air inlet hole; the micro vacuum pump, one end of which being connected with the dust removal and dehumidification device through a pipeline, and the other end of which being connected with the electronic flowmeter; and the plurality of different gas sensors. The disclosure includes an analysis method based on the on-line multi-component gas analysis system based on a spectral absorption technology.

Abstract: The disclosure includes an air quantity analyzer for use in underground coal mines, comprising an explosion-proof enclosure. According to some embodiments, the air quantity analyzer for use in underground coal mines comprises a gas pipeline inside of the explosion-proof enclosure, the gas pipeline coupled to a mechanical component selected from the group consisting of an air sampler, a gas pool, and combinations thereof, a detection device inside of the explosion-proof enclosure, the detection device having a vacuum pump, wherein the vacuum pump is coupled to the gas pipeline, and a central processor inside of the explosion-proof enclosure and electrically coupled to the vacuum pump of the detection device, the central processor electrically coupled to an electric component selected from the group consisting of a light source, a detector, a power conversion module, a display and alarm module, a data communication module, and combinations thereof.

Abstract: An acoustic while drilling receiving transducer array adopts a full-digital structure and a non-oil-filled rubber encapsulation arrangement mode, and the full-digital device of the acoustic while drilling receiving transducer array includes first modules, configured to carry out acoustic-to-electric conversion on weakly received acoustic signals of strata; second modules, configured to carry out amplification, filtering, gain control and digital-to-analog conversion on the weakly received acoustic signals; and a third module, configured to control interfaces of the device and convert external input and output signals.

Abstract: An acoustic while drilling receiving transducer array adopts a full-digital structure and a non-oil-filled rubber encapsulation arrangement mode, and the full-digital device of the acoustic while drilling receiving transducer array includes first modules, configured to carry out acoustic-to-electric conversion on weakly received acoustic signals of strata; second modules, configured to carry out amplification, filtering, gain control and digital-to-analog conversion on the weakly received acoustic signals; and a third module, configured to control interfaces of the device and convert external input and output signals.

Abstract: An electrode-type near-bit wireless short-distance transmission modulation method includes the steps of by a near-bit measuring tool, measuring parameters, and acquiring parameter information, and packing the parameter information into a data packet, and transmitting the data packet to a transmission processor part; by the transmission processor part, performing binary frequency shift keying modulation on the data packet, and according to a set transmission power and driving source power, passing the modulated data packet through an amplifying circuit and a driving circuit, and then loading the modulated data packet to positive and negative electrodes of a transmitter; and by the positive and negative electrodes of the transmitter, transmitting the modulated data packet passed through the amplifying circuit and the driving circuit to a receiver, so as to realize electrode-type wireless short-distance transmission modulation.

Abstract: A sonic logging broadband impedance matching transformer modular design method and a module are related to sonic logging. The method includes the steps: obtaining component values of a multimodal equivalent circuit of a piezoelectric transducer by fitting actual impedance data of the piezoelectric transducer through a nonlinear regression method; selecting a T-type network structure composed of a matching capacitor and a matching inductor as a piezoelectric transducer impedance matching network structure; and presetting a to-be-matched frequency band and a reflection coefficient, and taking the multimodal equivalent circuit of the transducer as an artificial circuit load to optimize parameters of the piezoelectric transducer impedance matching network structure and a boosting transformer together so as to obtain final optimized parameters of the piezoelectric transducer impedance matching network structure and the transformer.

Abstract: In a method for acquiring data of azimuthal acoustic LWD, when an acoustic LWD instrument rotates with a drilling tool at a certain depth, data is acquired by adopting an azimuthal equal-interval mode: a well circumference is divided into m sectors by azimuthal intervals ??, when a toolface angle of the acoustic LWD instrument is located in the kth sector, an acoustic transmitting source is controlled to transmit an acoustic signal, and an acoustic receiver measures the acoustic signal, digitizes it and then stores it as data in the kth sector; and the data is acquired for each sector in turn, and after the data is acquired in each sector for N times, the data acquisition at the current depth is completed. Meanwhile, as the drilling tool rotates and drills, the instrument acquires acoustic data at different depths and processes it to achieve azimuthal acoustic imaging.

Abstract: A sonic logging broadband impedance matching transformer modular design method and a module are related to sonic logging. The method includes the steps: obtaining component values of a multimodal equivalent circuit of a piezoelectric transducer by fitting actual impedance data of the piezoelectric transducer through a nonlinear regression method; selecting a T-type network structure composed of a matching capacitor and a matching inductor as a piezoelectric transducer impedance matching network structure; and presetting a to-be-matched frequency band and a reflection coefficient, and taking the multimodal equivalent circuit of the transducer as an artificial circuit load to optimize parameters of the piezoelectric transducer impedance matching network structure and a boosting transformer together so as to obtain final optimized parameters of the piezoelectric transducer impedance matching network structure and the transformer.

Abstract: An apparatus for measuring gravity acceleration of a drilling tool comprises sensors and a measurement circuit. The sensor comprises a three-axis gravity accelerometer, a reference measurement sensor and a temperature sensor. The three-axis gravity accelerometer measures acceleration component signals in three mutually orthogonal directions, and the reference measurement sensor generates a signal that varies with rotation and is not affected by vibration or shock to serve as a reference signal. The temperature sensor measures the temperature in the apparatus to compensate the temperature effect of the gravity accelerometers. The measurement circuit acquires output signals of the sensors and performs cross-correlation processing on the accelerometer components using the reference signal to extract gravity acceleration signals so as to eliminate centrifugal acceleration, vibration, shock and other interferences generated by rotation.

Abstract: A near-bit wireless constant current short-distance transmission device has an emission part and a receiving part. The emission part modulates a signal and then wirelessly transmits the modulated signal to the receiving part. The emission part transmits an emission signal into a stratum according to a set rated emission constant current value, and dynamically monitors and adjusts the rated emission constant current value of the emission signal to obtain stable emission power.

Abstract: A near-bit wireless constant current short-distance transmission device has an emission part and a receiving part. The emission part modulates a signal and then wirelessly transmits the modulated signal to the receiving part. The emission part transmits an emission signal into a stratum according to a set rated emission constant current value, and dynamically monitors and adjusts the rated emission constant current value of the emission signal to obtain stable emission power.

Abstract: In a method for synchronizing acoustic asynchronous serial signals while drilling, communication and high-voltage signal isolation between a transmitting terminal and a receiving master control board are realized in an asynchronous serial communication way. The receiving master control board serving as a master control terminal configures parameters for the transmitting terminal in the asynchronous serial communication way and controls the excitation of a sound source. The transmitting terminal is a synchronous sound source excitation signal initiator; signal synchronization is realized under an asynchronous communication condition due to the coordination of the transmitting terminal and the receiving master control board; the transmitting terminal includes a plurality of transmitting boards, and asynchronous serial communication between each of the transmitting boards and the receiving master control board is realized through two data lines R+ and R.

Abstract: In a method for synchronizing acoustic asynchronous serial signals while drilling, communication and high-voltage signal isolation between a transmitting terminal and a receiving master control board are realized in an asynchronous serial communication way. The receiving master control board serving as a master control terminal configures parameters for the transmitting terminal in the asynchronous serial communication way and controls the excitation of a sound source. The transmitting terminal is a synchronous sound source excitation signal initiator; signal synchronization is realized under an asynchronous communication condition due to the coordination of the transmitting terminal and the receiving master control board; the transmitting terminal includes a plurality of transmitting boards, and asynchronous serial communication between each of the transmitting boards and the receiving master control board is realized through two data lines R+ and R.

Abstract: The disclosure relates to the field of drilling tool attitude measurement, and particularly to a dynamic testing device suitable for a drilling tool attitude measurement module. The dynamic testing device may comprise a test fixture for attitude measurement module, an azimuth rotation device for adjusting an azimuth angle, an inclination angle swing device for adjusting an inclination angle, and a toolface angle rotation device for driving the test fixture for attitude measurement module to rotate, and a rotation speed measurement device for measuring a rotation speed and a self-rotation angle of the test fixture for attitude measurement module in a rotating state. The testing device has characteristics of large bearing weight, high rotation speed which is measurable and controllable, convenient for mounting and fixing a tested module, etc. It can simulate conditions of downhole rotation of a drilling tool, and be used for dynamic testing of the attitude measurement module.

Abstract: A near-bit constant-power wireless short-distance transmission apparatus includes a transmitting portion and a receiving portion. The transmitting portion is connected to a near-bit measurement sub while the receiving portion is connected to a measurement while drilling system. The transmitting portion processes data received by the bit measurement sub and then transmits it to the receiving portion. The receiving portion further processes the information and then transmits it to the measurement while drilling system. An insulating sub is inserted in the transmitting portion and separates the transmitting portion into a transmitting positive pole and a transmitting negative pole, which become electrically isolated from each other. Another insulating sub is inserted in the receiving portion and separates the receiving portion into a receiving positive pole and a receiving negative pole, which become electrically isolated from each other.

Abstract: An azimuthal acoustic LWD apparatus is sequentially provided with a centralizer, a transmitting circuit, transmitting transducers, an acoustic insulator, a receiving transducer array, ultrasonic transducers and a receiving circuit on a drill collar. The azimuthal acoustic LWD apparatus is capable of operating in a dipole mode or a unipole mode, to cover all the sectors around a wellbore by adopting a fixed time interval measurement mode or an alternating time interval measurement mode according to a relationship of an interval between measurement times and a rotation speed of the apparatus, thereby achieving azimuthal acoustic LWD. This apparatus overcomes problems that the fixed time interval measurement mode may not cover all the sectors and further may not achieve azimuthal acoustic imaging in a case where the rotation speed and the interval between measurement times are under certain conditions.