Gas extraction flow and concentration integrated monitoring device based on ultrasonic principle

Abstract

The invention discloses a gas extraction flow and concentration integrated monitoring device based on an ultrasonic principle. The gas extraction flow and concentration integrated monitoring device comprises a main pipe, an auxiliary pipe, a transducer group I, a transducer group II, a control circuit board, a carbon dioxide temperature and humidity integrated detection probe and a liquid crystal display screen, a circuit and a display screen are installed on a middle box body, a top through hole is in butt joint with an auxiliary pipe, and the auxiliary pipe is provided with a gas diffusion channel to form a static gas sample. The gas flow velocity is measured through the transducer group I, the methane concentration is measured through the transducer group II, and the temperature, the humidity and the carbon dioxide concentration are collected in real time by the probe; the control circuit board integrates modules such as a single-chip microcomputer minimum system and the like, drives components and processes data, a linear interpolation method correction model is built in to eliminate environmental interference, and a display screen displays multiple parameters in real time. The system is high in integration degree and strong in environmental interference resistance, can realize accurate and real-time synchronous monitoring of gas flow, methane concentration, gas temperature and humidity and carbon dioxide concentration, and reduces equipment deployment and operation and maintenance cost.

Description

Technical Field

[0001] This invention relates to the field of mine gas extraction and monitoring technology, and in particular to an integrated monitoring device for gas extraction flow rate and concentration based on ultrasonic principles. Background Technology

[0002] Mine gas drainage is a core component of safe coal mine production. Real-time and accurate monitoring of flow rate and methane concentration parameters during gas drainage is crucial for assessing drainage efficiency, controlling gas leakage risks, and ensuring safe underground operations. With increasing coal mining depth and intensity, the volume of underground gas emissions and the complexity of drainage systems have significantly increased, placing higher demands on the environmental adaptability, measurement accuracy, and integration level of gas monitoring devices.

[0003] Currently, traditional instruments used for gas drainage monitoring in coal mines generally adopt a separate design for flow monitoring and concentration monitoring devices, and the core measuring components are mostly contact sensors. This existing technology has the following technical drawbacks: First, it has poor resistance to adverse environments. The underground gas drainage environment is characterized by high dust, high humidity, and strong vibration. The sensitive elements of traditional contact sensors are in direct contact with the gas flow, making them susceptible to dust blockage, corrosion from humid gases, or damage from vibration. This leads to shortened sensor lifespan, frequent measurement drift, and the need for frequent shutdowns for maintenance, severely affecting the continuity of monitoring.

[0004] Secondly, accuracy is poor in special operating sections. Traditional concentration monitoring devices are mostly installed directly inside the main extraction pipeline. The gas flow velocity in the main pipeline fluctuates greatly, especially in special operating sections such as the start-up and shutdown of the extraction pump and the adjustment of pipeline valves. The high-speed flow field will interfere with the sensor's stable detection of gas components, resulting in significant deviations in the measured methane concentration. At the same time, if the flow monitoring device does not take into account the influence of uneven flow field distribution, flow calculation errors are also prone to occur in areas with uneven flow velocity in the pipeline cross-section.

[0005] Third, the integrated monitoring capability is poor. Flow and concentration need to be measured separately by two independent devices. The signal acquisition and data processing systems of the two devices are independent of each other. This not only requires multiple installation interfaces on the extraction pipeline, increasing the risk of pipeline leakage, but also requires the deployment of multiple sets of data transmission lines, resulting in low system integration and complex on-site wiring.

[0006] Fourth, the cost is high and the monitoring data is lagging. The split design requires the separate purchase, installation and calibration of two sets of equipment, resulting in high equipment purchase and construction costs. At the same time, the data processing speed of traditional equipment is slow, and some of it relies on manual periodic reading or offline analysis. It is impossible to transmit monitoring data to the mine monitoring center in real time. When the gas concentration is abnormal or the flow rate changes suddenly, it is difficult to trigger an early warning in time, which poses a safety hazard.

[0007] In summary, existing gas extraction monitoring technologies suffer from problems such as weak resistance to environmental interference, insufficient measurement accuracy, low integration, high cost, and data lag, making it difficult to meet the needs of modern coal mines for efficient, accurate, and real-time monitoring of the gas extraction process. There is an urgent need to develop an integrated monitoring technology solution that can overcome the above-mentioned defects. Summary of the Invention

[0008] To address the aforementioned technical issues, this invention provides an integrated monitoring device for gas extraction flow and concentration based on ultrasonic principles. It has excellent resistance to environmental interference and can achieve accurate, real-time, and synchronous monitoring of gas flow, methane concentration, gas temperature and humidity, and carbon dioxide concentration, thereby reducing equipment deployment and maintenance costs.

[0009] The technical solution adopted by the present invention to solve its technical problem is: an integrated monitoring device for gas extraction flow and concentration based on ultrasonic principle, including a main pipe, a secondary pipe, transducer group I, transducer group II, an LCD screen, a control circuit board, and an integrated carbon dioxide temperature and humidity detection probe. The main pipe is equipped with flanges at both ends for connecting to mine gas extraction pipelines; a housing for installing an LCD screen and control circuit board is located in the middle of the main pipe body. The outer wall of the main pipe is provided with two through holes for connecting to the secondary pipe; one of the two through holes is designated as the inlet hole, which is closer to the direction of airflow from the main pipe, and the other is designated as the outlet hole. The airflow in the main pipe enters the secondary pipe through the inlet hole and exits from the secondary pipe through the outlet hole. The main pipe is provided with a transducer channel I; the secondary pipe is provided with a transducer channel II and a gas diffusion channel; the transducer group I is installed in the transducer channel I of the main pipe for measuring the gas flow rate; the transducer group II is installed in the transducer channel II of the secondary pipe for measuring the methane concentration. The integrated carbon dioxide temperature and humidity detection probe is installed inside the main pipe to detect the carbon dioxide concentration, temperature, and humidity of the gas inside the main pipe. The transducer group I, transducer group II, LCD screen, and integrated carbon dioxide temperature and humidity detection probe are all electrically connected to the control circuit board.

[0010] Furthermore, the control circuit board includes a microcontroller minimum system module, a flow detection module, a methane concentration detection module, and a parameter display module; the microcontroller minimum system module is used for signal output and data processing; the flow detection module is electrically connected to transducer group I, and is used to drive transducer group I to emit ultrasonic waves and receive its feedback signals; the methane concentration detection module is electrically connected to transducer group II and a carbon dioxide temperature and humidity integrated detection probe, respectively, and is used to drive transducer group II to emit ultrasonic waves, receive its feedback signals, and collect carbon dioxide temperature and humidity data; the parameter display module is electrically connected to an LCD screen, and is used to drive the LCD screen to display the monitoring parameters; The flow detection module of the control circuit board includes an ultrasonic pulse signal driving circuit, a switch switching circuit, and an ultrasonic receiving circuit; the ultrasonic pulse signal driving circuit is used to generate ultrasonic pulse signals to drive transducer group I; the ultrasonic receiving circuit is used to receive the ultrasonic signals fed back by transducer group I and convert them into electrical signals. The methane concentration detection module of the control circuit board includes an ultrasonic continuous signal driving circuit, an ultrasonic receiving circuit, and a temperature, humidity, and carbon dioxide detection circuit. The ultrasonic continuous signal driving circuit is used to generate a continuous ultrasonic signal to drive transducer group II. The ultrasonic receiving circuit is used to receive the ultrasonic signal fed back from transducer group II and convert it into an electrical signal. The temperature, humidity, and carbon dioxide detection circuit is used to collect the detection data of the integrated carbon dioxide, temperature, and humidity detection probe.

[0011] Furthermore, the transducer channel I on the main pipe is at a 45° angle to the airflow direction inside the main pipe.

[0012] Furthermore, the secondary pipe is detachably connected to the main pipe.

[0013] Furthermore, the transducer group I includes ultrasonic transducer A and ultrasonic transducer B, both of which have ultrasonic transmission and reception functions; the switch switching circuit in the flow detection module is used to switch the transmission and reception modes of ultrasonic transducer A and ultrasonic transducer B. The transducer group II includes an ultrasonic transducer C and an ultrasonic transducer D. The ultrasonic transducer C is used to emit ultrasonic waves, and the ultrasonic transducer D is used to receive ultrasonic waves.

[0014] Furthermore, the integrated carbon dioxide temperature and humidity detection probe is installed on the inner wall of the main pipe near the inlet hole.

[0015] Furthermore, the specific method by which the integrated monitoring device measures the gas flow velocity through the transducer group I is as follows: Step-a1: Under the control of the microcontroller minimum system module, the switching circuit first sets ultrasonic transducer A to transmit mode and ultrasonic transducer B to receive mode. The ultrasonic pulse signal driving circuit drives ultrasonic transducer A to transmit ultrasonic waves. After transducer B receives the ultrasonic waves, the ultrasonic receiving circuit transmits the signal to the microcontroller minimum system module. The microcontroller minimum system module records the downstream propagation time t of the ultrasonic waves. s ; Step-a2: Subsequently, the switching circuit switches to transducer B in transmit mode and transducer A in receive mode, repeating the signal transmission and reception process of Step-a1. The microcontroller minimum system module records the ultrasonic backflow propagation time t. n ; Step-a3: The microcontroller minimum system module calls the preset parameters: the inner diameter D of the main pipe, the ultrasonic propagation length L between transducers A and B in transducer group I, and the angle θ between transducer channel I and the airflow direction; then substitute them into the formula. The instantaneous flow velocity of the gas gas is obtained; In the formula, v is the instantaneous velocity of the gas flow, in m / s; D is the inner diameter of the main pipe, in m; L is the ultrasonic propagation length of transducer group I, in m; and t s The time for ultrasonic waves to propagate downstream is measured in seconds (s); t n θ is the ultrasonic wave propagation time in the reverse direction, measured in seconds; θ is the angle between transducer channel I and the airflow direction, measured in rad.

[0016] Furthermore, the specific method by which the integrated monitoring device measures methane concentration through transducer group II is as follows: Step-b1: The ultrasonic continuous signal driving circuit drives the ultrasonic transducer C to emit ultrasonic waves of a fixed frequency. After receiving the ultrasonic waves, the ultrasonic transducer D transmits the signal to the ultrasonic receiving circuit of the methane concentration detection module. Step-b2: The methane concentration detection module compares the received ultrasonic signal with the internally preset reference signal to obtain the phase difference φ between the two, and transmits φ to the microcontroller minimum system module; Step-b3: The microcontroller minimum system module incorporates a temperature, humidity, and carbon dioxide correction mathematical model. This model, based on linear interpolation, is used to eliminate the interference of temperature, humidity, and carbon dioxide concentration on the methane concentration measurement results. The microcontroller minimum system module reads the current temperature T from the integrated carbon dioxide and temperature / humidity detection probe in real time. x Humidity H x and carbon dioxide concentration y; and call the preset constant, then substitute it into the formula: ; Obtain the methane concentration in the gas sample to be measured; In the formula, x is the methane concentration in the gas sample to be measured, in %; K1, K2, and K3 are corrected gas constants, corresponding to the propagation characteristic coefficients of ultrasound in pure air, 100% methane, and 100% carbon dioxide, respectively; L is the propagation distance between ultrasonic transducer groups II, in meters; T0 is the reference temperature under standard conditions, in K; H0 is the reference relative humidity under standard conditions, in %; T x The temperature of the gas sample is collected in real time by the integrated carbon dioxide temperature and humidity detection probe, and the unit is K; H. xy is the relative humidity of the current gas sample collected in real time by the integrated carbon dioxide temperature and humidity detection probe, in units of %; y is the carbon dioxide concentration in the current gas sample collected in real time by the integrated carbon dioxide temperature and humidity detection probe, in units of %; θ is a parameter related to the ultrasonic phase difference, which is derived from the phase difference φ measured by ultrasonic transducer group II and combined with the ultrasonic frequency f.

[0017] The beneficial effects of this invention; 1. This invention, through a modular design of the main and auxiliary pipes, simultaneously achieves real-time monitoring of key parameters such as instantaneous gas flow rate, cumulative gas flow rate, methane concentration, carbon dioxide concentration, and gas temperature and humidity. Unlike existing technologies, it eliminates the need for separate deployments of flow monitors, methane concentration meters, temperature and humidity sensors, and carbon dioxide detectors. This improves system integration, reduces the number of installation interfaces on the extraction pipeline, and lowers the risk of gas leakage due to poor sealing of multiple interfaces. Simultaneously, it eliminates the need for independent wiring between multiple devices, reducing on-site construction complexity and adapting to the narrow pipeline installation environment in coal mines.

[0018] 2. The present invention features a gas diffusion channel in the secondary pipe to form a static gas sample, avoiding interference from the high-speed flow field in the main pipe on concentration measurement. Combined with a temperature, humidity, and carbon dioxide correction model, it effectively improves the accuracy of methane concentration measurement. The main pipe transducer channel I is at a 45° angle to the airflow, and transducer group I measures the flow velocity using the ultrasonic time-of-flight method, improving the accuracy of gas flow velocity measurement and effectively solving the measurement deviation caused by flow field and environmental parameters in traditional devices. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0020] Figure 2 This is a top view used to illustrate the main structure in this invention.

[0021] Figure 3 This is a side view used to illustrate the main structure in this invention.

[0022] Figure 4 This is a front view used to illustrate the secondary pipe structure in this invention.

[0023] Figure 5 This is a side view used to illustrate the secondary tube structure in this invention.

[0024] Figure 6 This is the bottom view used to illustrate the secondary pipe structure in this invention.

[0025] Figure 7 This is the operational logic diagram of the present invention.

[0026] In the diagram: 1. Main pipe; 2. Secondary pipe; 3. Transducer group I; 4. Transducer group II; 5. LCD screen; 7. Carbon dioxide temperature and humidity integrated detection probe; 8. Transducer channel I; 9. Housing; 10. Transducer channel II; 11. Gas diffusion channel; 12. Flange; 13. Through hole. Detailed Implementation

[0027] The present invention will be further described in detail below with reference to the accompanying drawings.

[0028] This invention discloses an integrated monitoring device for gas extraction flow rate and concentration based on ultrasonic principles.

[0029] Reference Figure 1-7 A gas extraction flow and concentration integrated monitoring device based on ultrasonic principle includes a main pipe 1, a secondary pipe 2, a transducer group I 3, a transducer group II 4, an LCD screen 5, a control circuit board and a carbon dioxide temperature and humidity integrated detection probe 7. Flanges 12 are welded to both ends of the main pipe 1 for sealing connection with the mine gas extraction pipeline, enabling the flow of gas gas within the main pipe 1. A housing for mounting the LCD display screen 5 and control circuit board is located in the middle of the main pipe 1.

[0030] Two through holes 13 are spaced apart on the top of the outer wall of the main pipe 1 along the airflow direction for connecting to the secondary pipe 2; one of the two through holes 13 is designated as the inlet hole, which is closer to the airflow direction of the main pipe 1, and the other is designated as the outlet hole. The airflow in the main pipe 1 enters the secondary pipe 2 through the inlet hole and is discharged back to the main pipe 1 from the secondary pipe 2 through the outlet hole; the secondary pipe 2 and the main pipe 1 are detachably connected by screws.

[0031] The main pipe 1 is provided with a transducer channel I8, which is at a 45° angle to the airflow direction inside the main pipe 1; the secondary pipe 2 is provided with a transducer channel II10 and a gas diffusion channel 11; the aperture of the gas diffusion channel is smaller than the inner diameter of the secondary pipe 2, which is used to slow down the flow velocity of the gas gas in the secondary pipe 2 and form a static gas sample to be tested.

[0032] Transducer group I3 is fixedly installed in transducer channel I8 of main pipe 1 and is used to measure gas flow rate. Transducer group I3 includes ultrasonic transducer A and ultrasonic transducer B. Both ultrasonic transducer A and ultrasonic transducer B have ultrasonic transmission and reception functions. The switch switching circuit in the flow detection module is used to switch the transmission and reception modes of ultrasonic transducer A and ultrasonic transducer B. Transducer group II4 is installed in transducer channel II10 of secondary pipe 2 and is used to measure methane concentration. Transducer group II4 includes ultrasonic transducer C and ultrasonic transducer D. Ultrasonic transducer C is used to emit ultrasonic waves and ultrasonic transducer D is used to receive ultrasonic waves.

[0033] The carbon dioxide temperature and humidity integrated detection probe 7 is installed inside the main pipe 1 to detect the carbon dioxide concentration, temperature and humidity of the gas inside the main pipe 1; the carbon dioxide temperature and humidity integrated detection probe 7 is installed inside the main pipe 1 near the inlet hole on the inner wall.

[0034] Transducer group I 3, transducer group II 4, LCD display 5, and carbon dioxide temperature and humidity integrated detection probe 7 are all electrically connected to the control circuit board.

[0035] The control circuit board includes a microcontroller minimum system module, a flow detection module, a methane concentration detection module, and a parameter display module. The microcontroller minimum system module is used for signal output and data processing. The flow detection module is electrically connected to transducer group I3 and is used to drive transducer group I3 to emit ultrasonic waves and receive its feedback signals. The methane concentration detection module is electrically connected to transducer group II4 and the integrated carbon dioxide temperature and humidity detection probe 7, respectively, and is used to drive transducer group II4 to emit ultrasonic waves, receive its feedback signals, and collect carbon dioxide temperature and humidity data. The parameter display module is electrically connected to the LCD screen 5 and is used to drive the LCD screen 5 to display the monitoring parameters. The flow detection module of the control circuit board includes an ultrasonic pulse signal driving circuit, a switch switching circuit, and an ultrasonic receiving circuit; the ultrasonic pulse signal driving circuit is used to generate ultrasonic pulse signals to drive transducer group I3; the ultrasonic receiving circuit is used to receive the ultrasonic signals fed back by transducer group I3 and convert them into electrical signals. The methane concentration detection module of the control circuit board includes an ultrasonic continuous signal driving circuit, an ultrasonic receiving circuit, and a temperature, humidity, and carbon dioxide detection circuit. The ultrasonic continuous signal driving circuit is used to generate a continuous ultrasonic signal to drive transducer group II4. The ultrasonic receiving circuit is used to receive the ultrasonic signal fed back by transducer group II4 and convert it into an electrical signal. The temperature, humidity, and carbon dioxide detection circuit is used to collect the detection data of the integrated carbon dioxide, temperature, and humidity detection probe 7.

[0036] The specific method by which this integrated monitoring device measures gas flow velocity through transducer group I3 is as follows: Step-a1: Under the control of the microcontroller minimum system module, the switching circuit first sets ultrasonic transducer A to transmit mode and ultrasonic transducer B to receive mode. The ultrasonic pulse signal driving circuit drives ultrasonic transducer A to transmit ultrasonic waves. After transducer B receives the ultrasonic waves, the ultrasonic receiving circuit transmits the signal to the microcontroller minimum system module. The microcontroller minimum system module records the downstream propagation time t of the ultrasonic waves. s ; Step-a2: After an interval of 0.1s-0.5s, the switching circuit switches to transducer B in transmit mode and transducer A in receive mode, repeating the signal transmission and reception process of Step-a1. The microcontroller minimum system module records the ultrasonic backflow propagation time t.n ; Step-a3: The microcontroller minimum system module calls the preset parameters: the inner diameter D of the main pipe 1, the ultrasonic propagation length L between transducers A and B in transducer group I3, and the angle θ between transducer channel I8 and the airflow direction; then substitute them into the formula. The instantaneous flow velocity of the gas gas is obtained; In the formula, v is the instantaneous velocity of the gas flow, in m / s; D is the inner diameter of main pipe 1, in m; L is the ultrasonic propagation length of transducer group I3, in m; and t s The time for ultrasonic waves to propagate downstream is measured in seconds (s); t n θ is the ultrasonic wave propagation time in the reverse direction, in seconds; θ is the angle between transducer channel I8 and the airflow direction, in rad.

[0037] The specific method by which this integrated monitoring device measures methane concentration using transducer group II4 is as follows: Step-b1: The ultrasonic continuous signal driving circuit drives the ultrasonic transducer C to emit ultrasonic waves of a fixed frequency. After receiving the ultrasonic waves, the ultrasonic transducer D transmits the signal to the ultrasonic receiving circuit of the methane concentration detection module. Step-b2: The methane concentration detection module compares the received ultrasonic signal with the internally preset reference signal (i.e., a standard sine wave signal of the same frequency) to obtain the phase difference φ between the two, and transmits φ to the microcontroller minimum system module. Step-b3: The microcontroller minimum system module incorporates a temperature, humidity, and carbon dioxide correction mathematical model. This model, based on linear interpolation, is used to eliminate the interference of temperature, humidity, and carbon dioxide concentration on the methane concentration measurement results. The microcontroller minimum system module reads the current temperature T from the integrated carbon dioxide and temperature / humidity detection probe 7 in real time. x Humidity H x and carbon dioxide concentration y; and call the preset constant, then substitute it into the formula: ; Obtain the methane concentration in the gas sample to be measured; In the formula, x is the methane concentration in the gas sample to be measured, in % (%). K1 is the laboratory-calibrated corrected gas constant, which corresponds to the propagation characteristic coefficient of ultrasound in pure air under standard conditions such as 0℃ and 1 standard atmosphere. It is pre-stored in the storage unit of the microcontroller minimum system module. K2 is a corrected gas constant calibrated in the laboratory, corresponding to the propagation characteristic coefficient of ultrasound in 100% volume concentration methane under standard conditions, and is pre-stored in the microcontroller's memory unit. K3 is a corrected gas constant calibrated in the laboratory, corresponding to the propagation characteristic coefficient of ultrasound in 100% volume concentration carbon dioxide under standard conditions, and is pre-stored in the microcontroller's memory unit. L is the propagation distance between ultrasonic transducers C and D in ultrasonic transducer group II4, in meters. T0 is the reference temperature under standard conditions, in K, and is the reference temperature for calibrating K1, K2, and K3. H0 is the reference relative humidity under standard conditions, expressed in %; it is the reference temperature for calibrating K1, K2, and K3. T x The temperature of the gas sample is collected in real time by the carbon dioxide temperature and humidity integrated detection probe 7, and the unit is K. H x The relative humidity of the current gas sample is collected in real time by the carbon dioxide temperature and humidity integrated detection probe 7. The carbon dioxide concentration in the current gas sample, measured in real time by the carbon dioxide temperature and humidity integrated detection probe 7, is expressed as % (%). The parameter θ, which is related to the ultrasonic phase difference, is derived from the phase difference φ measured by the transducer array and the ultrasonic frequency f. Specifically, it is... .

[0038] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A gas extraction flow rate and concentration integrated monitoring device based on ultrasonic principle, characterized in that: Includes main pipe (1), secondary pipe (2), transducer group I (3), transducer group II (4), LCD screen (5), control circuit board and carbon dioxide temperature and humidity integrated detection probe (7); The main pipe (1) is provided with flanges (12) at both ends for connecting to the mine gas extraction pipeline; the main pipe (1) is provided with a box (9) in the middle for installing the LCD screen (5) and the control circuit board; The outer wall of the main pipe (1) is provided with two through holes (13) for connecting to the secondary pipe (2); one of the two through holes (13) is set as the inlet hole closer to the airflow direction of the main pipe (1), and the other is set as the outlet hole. The airflow in the main pipe (1) enters the secondary pipe (2) through the inlet hole and is discharged from the secondary pipe (2) through the outlet hole. The main pipe (1) is provided with a transducer channel I (8); the secondary pipe (2) is provided with a transducer channel II (10) and a gas diffusion channel (11); the transducer group I (3) is installed in the transducer channel I (8) of the main pipe (1) for measuring the gas flow rate; the transducer group II (4) is installed in the transducer channel II (10) of the secondary pipe (2) for measuring the methane concentration; The carbon dioxide temperature and humidity integrated detection probe (7) is installed inside the main pipe (1) and is used to detect the carbon dioxide concentration, temperature and humidity of the gas inside the main pipe (1); The transducer group I (3), transducer group II (4), liquid crystal display screen (5) and carbon dioxide temperature and humidity integrated detection probe (7) are all electrically connected to the control circuit board.

2. The integrated monitoring device for gas extraction flow rate and concentration based on ultrasonic principle according to claim 1, characterized in that: The control circuit board includes a single-chip microcomputer minimum system module, a flow detection module, a methane concentration detection module, and a parameter display module. The single-chip microcomputer minimum system module is used for signal output and data processing. The flow detection module is electrically connected to transducer group I (3) and is used to drive transducer group I (3) to emit ultrasonic waves and receive its feedback signals. The methane concentration detection module is electrically connected to transducer group II (4) and carbon dioxide temperature and humidity integrated detection probe (7) respectively and is used to drive transducer group II (4) to emit ultrasonic waves, receive its feedback signals, and collect carbon dioxide temperature and humidity data. The parameter display module is electrically connected to the liquid crystal display screen (5) and is used to drive the liquid crystal display screen (5) to display the monitoring parameters. The flow detection module of the control circuit board includes an ultrasonic pulse signal driving circuit, a switch switching circuit and an ultrasonic receiving circuit; the ultrasonic pulse signal driving circuit is used to generate ultrasonic pulse signals to drive transducer group I (3); the ultrasonic receiving circuit is used to receive the ultrasonic signals fed back by transducer group I (3) and convert them into electrical signals. The methane concentration detection module of the control circuit board includes an ultrasonic continuous signal driving circuit, an ultrasonic receiving circuit, and a temperature, humidity, and carbon dioxide detection circuit; the ultrasonic continuous signal driving circuit is used to generate an ultrasonic continuous signal to drive transducer group II (4); the ultrasonic receiving circuit is used to receive the ultrasonic signal fed back by transducer group II (4) and convert it into an electrical signal; the temperature, humidity, and carbon dioxide detection circuit is used to collect the detection data of the integrated carbon dioxide temperature and humidity detection probe (7).

3. The integrated monitoring device for gas extraction flow rate and concentration based on ultrasonic principle according to claim 2, characterized in that: The transducer channel I (8) on the main pipe (1) is at a 45° angle to the airflow direction inside the main pipe (1).

4. The integrated monitoring device for gas extraction flow rate and concentration based on ultrasonic principle according to claim 3, characterized in that: The secondary pipe (2) is detachably connected to the main pipe (1).

5. The integrated monitoring device for gas extraction flow and concentration based on ultrasonic principle according to claim 4, characterized in that: The transducer group I (3) includes ultrasonic transducer A and ultrasonic transducer B, both of which have ultrasonic transmission and reception functions; the switch switching circuit in the flow detection module is used to switch the transmission and reception modes of ultrasonic transducer A and ultrasonic transducer B. The transducer group II (4) includes an ultrasonic transducer C and an ultrasonic transducer D. The ultrasonic transducer C is used to emit ultrasonic waves, and the ultrasonic transducer D is used to receive ultrasonic waves.

6. The integrated monitoring device for gas extraction flow rate and concentration based on ultrasonic principle according to claim 5, characterized in that: The carbon dioxide temperature and humidity integrated detection probe (7) is installed inside the main tube (1) near the inlet hole on the inner wall.

7. The integrated monitoring device for gas extraction flow and concentration based on ultrasonic principle according to claim 6, characterized in that: The specific method by which the integrated monitoring device measures the gas flow velocity through the transducer group I (3) is as follows: Step-a1: Under the control of the microcontroller minimum system module, the switching circuit first sets ultrasonic transducer A to transmit mode and ultrasonic transducer B to receive mode. The ultrasonic pulse signal driving circuit drives ultrasonic transducer A to transmit ultrasonic waves. After transducer B receives the ultrasonic waves, the ultrasonic receiving circuit transmits the signal to the microcontroller minimum system module. The microcontroller minimum system module records the downstream propagation time t of the ultrasonic waves. s ; Step-a2: Subsequently, the switching circuit switches to transducer B in transmit mode and transducer A in receive mode, repeating the signal transmission and reception process of Step-a1. The microcontroller minimum system module records the ultrasonic backflow propagation time t. n ; Step-a3: The microcontroller minimum system module calls the preset parameters: the inner diameter D of the main tube (1), the ultrasonic propagation length L between transducer A and transducer B in transducer group I (3), and the angle θ between transducer channel I (8) and the airflow direction; then substitute them into the formula The instantaneous flow velocity of the gas gas is obtained; In the formula, v is the instantaneous velocity of the gas flow, in m / s; D is the inner diameter of the main pipe (1), in m; L is the ultrasonic propagation length of transducer group I (3), in m; t s The time for ultrasonic waves to propagate downstream is measured in seconds (s); t n θ is the ultrasonic wave propagation time in reverse flow, in seconds; θ is the angle between transducer channel I (8) and the airflow direction, in rad.

8. The integrated monitoring device for gas extraction flow and concentration based on ultrasonic principle according to claim 6, characterized in that: The specific method for measuring methane concentration using the integrated monitoring device via transducer group II (4) is as follows: Step-b1: The ultrasonic continuous signal driving circuit drives the ultrasonic transducer C to emit ultrasonic waves of a fixed frequency. After receiving the ultrasonic waves, the ultrasonic transducer D transmits the signal to the ultrasonic receiving circuit of the methane concentration detection module. Step-b2: The methane concentration detection module compares the received ultrasonic signal with the internally preset reference signal to obtain the phase difference φ between the two, and transmits φ to the microcontroller minimum system module; Step-b3: The microcontroller minimum system module has a built-in temperature, humidity and carbon dioxide correction mathematical model. The temperature, humidity and carbon dioxide correction mathematical model is constructed based on the linear interpolation method to eliminate the interference of temperature, humidity and carbon dioxide concentration on the methane concentration measurement results. The microcontroller minimum system module reads the current temperature T collected in real time by the carbon dioxide temperature and humidity integrated detection probe (7). x Humidity H x and carbon dioxide concentration y; and call the preset constant, then substitute it into the formula: ; Obtain the methane concentration in the gas sample to be measured; In the formula, x is the methane concentration in the gas sample to be measured, in %; K1, K2, and K3 are corrected gas constants, corresponding to the propagation characteristic coefficients of ultrasound in pure air, 100% methane, and 100% carbon dioxide, respectively; L is the propagation distance between the ultrasonic transducer group II (4), in m; T0 is the reference temperature under standard conditions, in K; H0 is the reference relative humidity under standard conditions, in %; T x The current gas sample temperature is collected in real time by the carbon dioxide temperature and humidity integrated detection probe (7), and the unit is K; H x y is the relative humidity of the current gas sample collected in real time by the carbon dioxide temperature and humidity integrated detection probe (7), in units of %; y is the carbon dioxide concentration in the current gas sample collected in real time by the carbon dioxide temperature and humidity integrated detection probe (7), in units of %; θ is a parameter related to the ultrasonic phase difference, which is derived from the phase difference φ measured by the ultrasonic transducer group II (4) and combined with the ultrasonic frequency f.

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