Multi-coal seam combined extraction separate source metering device and method

Abstract

The application discloses a kind of multi-coal seam joint extraction sub-source metering device, belong to coal mine gas extraction technical field, including extraction pipeline, metering unit, sealing unit, liquid injection unit and monitoring substation, further discloses a kind of multi-coal seam joint extraction sub-source metering method, the technical framework of independent metering of multi-coal seam sub-source is used in the application, the acquisition and real-time transmission of multi-coal seam joint extraction parameter are realized, effectively solve the industry pain point that traditional mixed extraction data cannot be traced to each single coal seam;Spring+capsule is used simultaneously in combination mode, capsule liquid injection expansion blocks borehole, the elastic force of strong compression spring itself will make capsule and hole wall close, better sealing, so that monitoring data is more accurate.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of coal mine gas extraction, and particularly provides a multi-coal seam combined extraction source separation metering device and method. BACKGROUND

[0002] With the continuous exploitation of coal resources, gas accidents have gradually become one of the main hidden dangers in the safety production of coal mines. Coal mine gas extraction is one of the core technical means of gas control in China, and gas extraction up to standard is a fundamental measure to ensure the safety production of mines. In this process, reliable gas extraction metering data is the key basis for evaluating the extraction up to standard. Coal mine gas extraction pipe network monitoring is the main tool for gas extraction metering. By monitoring the gas flow, concentration, temperature and pressure of the extraction pipeline in real time, gas extraction metering information is obtained, and the evaluation and analysis of coal seam gas extraction effect and extraction up to standard are realized. The most important thing in gas extraction metering is the monitoring of gas flow and concentration, which directly determines the accuracy of gas extraction up to standard evaluation.

[0003] At present, the gas extraction metering means mostly installs gas flow meters and concentration sensors on the extraction main pipeline to monitor the overall gas extraction parameters of the pre-extraction borehole, but in the process of coal seam group gas extraction, when a single extraction borehole penetrates multiple coal seams, the existing technology can only monitor the comprehensive parameters of the mixed gas of the coal seam group at the hole mouth. Because the gas in each coal seam in the borehole is mixed in the extraction pipe, it is impossible to accurately distinguish the key parameters such as extraction flow and concentration of each coal seam, which greatly affects the accuracy of the evaluation of extraction up to standard of each coal seam. SUMMARY

[0004] To solve the above problems, the present application provides a multi-coal seam combined extraction source separation metering device and method, which aims to solve the technical problem that the real extraction parameters of each coal seam cannot be accurately identified and metered in the process of multi-coal seam combined extraction, thereby causing distorted evaluation of extraction effect. The device and method can realize synchronous, independent and accurate metering of the gas extraction parameters (such as flow and concentration) of each coal seam in multi-coal seam combined extraction, thereby achieving the purpose of multi-coal seam combined extraction source separation metering.

[0005] To achieve the above purpose, the technical solution adopted by the present application is as follows: a multi-coal seam combined extraction source separation metering device, comprising an extraction pipeline, a metering unit, a hole sealing unit, a liquid injection unit and a monitoring substation, the extraction pipeline comprises an auxiliary ball head, a PVC screen pipe and a PVC extraction pipe, one end of the PVC screen pipe is equipped with a PVC extraction pipe arranged at the hole mouth of the borehole, the other end of the PVC screen pipe is equipped with an auxiliary ball head, and the PVC screen pipe penetrates all coal seams, the PVC screen pipes are connected through the metering unit between adjacent PVC screen pipes and between the PVC screen pipe and the PVC extraction pipe, and the hole sealing unit is arranged on the outside of the PVC extraction pipe.

[0006] The quantity of the metering unit corresponds to the quantity of the target coal layers, the metering unit comprises a drainage pipe connecting device, a flow acquisition device and a concentration sensor, the drainage pipe connecting device is assembled to the outer wall of adjacent PVC screen pipes, and the flow acquisition device and the concentration sensor are both assembled inside the drainage pipe connecting device, the flow acquisition device is assembled between adjacent PVC screen pipes, and the probe of the concentration sensor is arranged inside the PVC screen pipe.

[0007] The hole sealing unit comprises a lower fixed tray, an upper sliding tray, a strong compression spring and a hydraulic expansion capsule, the lower fixed tray and the upper sliding tray are sleeved and assembled to the outer wall of the PVC drainage pipe, the strong compression spring is fixedly installed between the lower fixed tray and the upper sliding tray, and the hydraulic expansion capsule is covered outside the strong compression spring.

[0008] The liquid injection unit is used for injecting liquid into the hydraulic expansion capsule.

[0009] The monitoring substation is used for powering the metering unit and receiving and displaying the parameter data monitored by the metering unit.

[0010] Further, recessed grooves are formed at both ends of the drainage pipe connecting device, a quick plug connector is fixedly installed in the recessed grooves through a loose joint spiral wire, the quick plug connector is sleeved outside the PVC screen pipe, and a sealing ring is assembled between the quick plug connector and the PVC screen pipe.

[0011] The flow acquisition device comprises a throttling element, an upper end face pressure tapping hole, a lower end face pressure tapping hole, a pressure guide pipe and a differential pressure transmitter, the throttling element is assembled between adjacent PVC screen pipes, the upper end face pressure tapping hole and the lower end face pressure tapping hole are respectively formed in the PVC screen pipes on the two sides of the throttling element, the differential pressure transmitter is fixedly installed on the drainage pipe connecting device, two pressure guide pipes are assembled on the differential pressure transmitter, and the pressure guide pipes are arranged in the upper end face pressure tapping hole and the lower end face pressure tapping hole.

[0012] Further, the metering unit further comprises an explosion-proof junction box, a temperature sensor and a pressure sensor, and the explosion-proof junction box, the temperature sensor and the pressure sensor are all assembled inside the drainage pipe connecting device, and the probes of the temperature sensor and the pressure sensor are arranged inside the PVC screen pipe.

[0013] Further, the outer wall of the lower fixed tray and the upper sliding tray is provided with a limiting recessed groove, the limiting recessed groove is provided with a quick plug connector and a sealing ring on the inner side, a hollow pipe is fixedly installed at the inner end of the lower fixed tray, and the upper sliding tray is movably assembled on the hollow pipe.

[0014] Further, the outside of the strong compression spring is provided with a telescopic shell, the hydraulic expansion capsule is coaxially covered and fixed outside the telescopic shell, and the two ends of the hydraulic expansion capsule are respectively sealed connected with the lower fixed tray and the upper sliding tray.

[0015] Further, the liquid injection unit comprises a hole sealing liquid injection pump, a liquid injection pressure gauge, a gas pipe through plug and a one-way stop valve, the liquid injection pressure gauge is assembled on the hole sealing liquid injection pump, the output end of the hole sealing liquid injection pump is provided with a capsule liquid injection pipe, the gas pipe through plug is arranged in the drilling hole, the one-way stop valve is arranged at the end of the capsule liquid injection pipe, and the capsule liquid injection pipe is communicated with the hydraulic expansion capsule through the gas pipe through plug.

[0016] Further, the monitoring substation comprises an explosion-proof power supply, an armored cable, an RS-485 signal line and a digital display meter, the explosion-proof power supply provides power for the metering unit through the armored cable arranged in a parallel mode, and the gas extraction parameters collected by the metering unit are transmitted to the digital display meter through the RS-485 signal line for display.

[0017] A multi-coal seam combined extraction sub-source metering method adopts the multi-coal seam combined extraction sub-source metering device, and specifically comprises the following steps.

[0018] Step 1, first, a through-hole drilling hole passing through all coal seams is constructed according to design, the drilling hole is stopped after passing through the last layer of coal seam by 1 m, and the first layer of coal seam to the last layer of coal seam at the hole bottom is sequentially numbered as M1, M2, …, M N The number of coal seam layers is determined to determine the group number N of metering units, and N≥2;

[0019] Step 2, the extraction pipeline and the metering unit are installed according to the occurrence of coal and rock strata, the PVC screen pipe passes through all coal seams, and is connected with the metering unit through the quick plug connector on the extraction pipe connecting device at the rear of the corresponding coal seam, and the N groups of metering units are arranged one by one from the rear of the first layer of coal seam at the hole bottom to the rear of the Nth layer of coal seam along the hole opening direction;

[0020] Step 3, the hole sealing unit is installed behind the hole opening metering unit, after the installation is completed, the hole sealing liquid injection pump is started, liquid is injected into each hydraulic expansion capsule through the capsule liquid injection pipe, after the hydraulic expansion capsule is expanded, the upper sliding tray is pushed to slide, so that the strong compression spring is in a stretched state, and after the liquid injection pressure reaches the set threshold value, the dynamic sealing of the multi-coal seam gas extraction drilling hole is realized;

[0021] Step 4, after the hole sealing is completed, the metering unit is powered by the explosion-proof power supply, the RS-485 signal line is connected with the digital display meter, the gas extraction parameters of the metering unit are displayed through the digital display meter, and the gas extraction parameters of each coal seam displayed by the digital display meter are monitored and recorded in real time;

[0022] Step 5, the multi-coal seam combined extraction separate source metering pipeline belongs to a series pipeline, the flow and concentration data monitored by the first layer coal seam metering unit close to the hole bottom are the real extraction data of the M1 coal seam, the real data of the second layer coal seam M2 is equal to the data monitored by the second metering unit minus the data monitored by the first metering unit, and so on, the real data of the Nth layer coal seam is equal to the data monitored by the Nth metering unit minus the data monitored by the N-1th metering unit, and the calculation formula is as follows:

[0023] Q M1 =Q1,η M1 =η1

[0024] Q M2 =Q2-Q1,η M2 =η2-η1

[0025] …

[0026] Q MN =Q N -Q N-1 ,η MN =η N -η N-1

[0027] Wherein:

[0028] Q M1 , Q M2 … Q MN are the gas flow of each coal seam;

[0029] η M1 , η M2 … η MN are the gas concentration of each coal seam.

[0030] The beneficial effects of using the present application are:

[0031] The present application adopts a multi-coal seam separate source independent metering technical framework, realizes the collection and real-time transmission of multi-coal seam combined extraction parameters for the first time, effectively solves the industry pain point that the traditional mixed extraction data cannot be traced back to each single coal seam; at the same time, the combination of "spring + capsule" is adopted, the capsule is expanded and blocked by liquid injection, the elastic force of the strong compression spring will make the capsule close to the hole wall, the sealing performance is good, so that the monitoring data is more accurate. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 It is the overall equipment structure schematic diagram of the embodiment one of the present application

[0033] Figure 2 It is the metering unit structure schematic diagram of the embodiment one of the present application

[0034] Figure 3The schematic diagram of the hole sealing unit structure of the first embodiment of the present application

[0035] Figure 4 The schematic diagram of the hole sealing unit tray profile result of the first embodiment of the present application

[0036] Figure 5 The schematic diagram of the overall equipment structure of the third embodiment of the present application

[0037] Figure 6 The schematic diagram of the wireless metering unit structure of the third embodiment of the present application

[0038] Figure 7 The schematic diagram of the overall equipment structure of the fourth embodiment of the present application.

[0039] The reference signs include: extraction pipeline 1, auxiliary ball head 11, PVC screen pipe 12, PVC extraction pipe 13, metering unit 2, extraction pipe connecting device 21, concave groove 211, quick plug 212, sealing ring 213, flow acquisition device 22, throttling member 221, upper end face pressure tapping hole 222, lower end face pressure tapping hole 223, pressure guide pipe 224, differential pressure transmitter 225, concentration sensor 23, explosion-proof junction box 24, temperature sensor 25, pressure sensor 26, hole sealing unit 3, lower fixed tray 31, upper sliding tray 32, limiting concave groove 33, strong compression spring 34, telescopic shell 341, hydraulic expansion capsule 35, hollow pipe 36, wiring channel 37, liquid injection channel 38, liquid injection unit 4, hole sealing liquid injection pump 41, liquid injection pressure gauge 42, capsule liquid injection pipe 43, tracheal straight plug 44, one-way stop valve 45, monitoring substation 5, explosion-proof power supply 51, armored cable 52, RS-485 signal line 53, digital display meter 54, explosion-proof battery pack 61, wireless communication sending end 62, wireless communication receiving end 63, digital display differential pressure meter 64, display screen 65. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0041] Embodiment one

[0042] Reference Figures 1 to 4The utility model provides a kind of multi-coal seam joint extraction source metering device, including extraction pipeline 1, metering unit 2, sealing unit 3, liquid injection unit 4 and monitoring substation 5, extraction pipeline 1 includes auxiliary ball head 11, PVC screen pipe 12 and PVC extraction pipe 13, one end of PVC screen pipe 12 is equipped with the PVC extraction pipe 13 arranged at borehole orifice, the other end of PVC screen pipe 12 is equipped with auxiliary ball head 11, and PVC screen pipe 12 penetrates all coal seams, adjacent PVC screen pipe 12, PVC screen pipe 12 and PVC extraction pipe 13 are connected by metering unit 2, sealing unit 3 is equipped with the outside of PVC extraction pipe 13.

[0043] Auxiliary ball head 11 is installed at the front end of the extraction pipeline, and the streamlined spherical structure effectively reduces the resistance between the pipeline and the inner wall of the extraction hole, and the auxiliary ball head 11 can smoothly enter the PVC screen pipe 12 into the extraction hole.

[0044] PVC screen pipe 12 is the main drainage channel for coal seam gas, and is arranged to penetrate all coal seams, PVC extraction pipe 13 is arranged at the orifice and connected with sealing unit 3, and adjacent PVC screen pipes 12 and PVC screen pipe 12 and PVC extraction pipe 13 are connected by sleeve type.

[0045] PVC screen pipe 12 is uniformly provided with air holes on the surface, and is connected with negative pressure equipment outside, and gas is extracted by negative pressure, so that gas in each coal seam can flow into the corresponding PVC screen pipe 12 under the action of negative pressure.

[0046] The number of metering units 2 corresponds to the number of target coal seams, and the metering unit 2 includes extraction pipe connecting device 21, flow acquisition device 22 and concentration sensor 23, the extraction pipe connecting device 21 is arranged on the outer wall of adjacent PVC screen pipes 12, and the flow acquisition device 22 and the concentration sensor 23 are arranged inside the extraction pipe connecting device 21, the flow acquisition device 22 is arranged between adjacent PVC screen pipes 12, and the probe of the concentration sensor 23 is arranged inside the PVC screen pipe 12.

[0047] Specifically, recessed grooves 211 are provided at both ends of the extraction pipe connecting device 21, quick connectors 212 are fixedly installed in the recessed grooves 211 by loose joint spiral wires, the quick connectors 212 are sleeved outside the PVC screen pipe 12, and sealing rings 213 are arranged between the quick connectors 212 and the PVC screen pipe 12 to realize sealed connection between adjacent extraction pipe sections.

[0048] The flow collecting device 22 comprises a throttling element 221, an upper end face pressure tapping hole 222, a lower end face pressure tapping hole 223, a pressure guide pipe 224 and a differential pressure transmitter 225. The throttling element 221 is assembled between adjacent PVC screen pipes 12. The upper end face pressure tapping hole 222 and the lower end face pressure tapping hole 223 are respectively arranged on the PVC screen pipes 12 on both sides of the throttling element 221. The differential pressure transmitter 225 is fixedly installed on the extraction pipe connecting device 21. Two pressure guide pipes 224 are assembled on the differential pressure transmitter 225, and the pressure guide pipes 224 are arranged in the upper end face pressure tapping hole 222 and the lower end face pressure tapping hole 223. The pressure data generated before and after the flow passing through the throttling element 221 is collected.

[0049] The throttling element 221 can be a orifice plate throttling element, i.e. an orifice plate flowmeter. In addition, it can also include a wedge throttling element, a nozzle throttling element and a V-shaped cone throttling element, etc. The calculation method of the orifice plate flowmeter is as follows:

[0050] ;

[0051] Wherein:

[0052] Q is the gas flow;

[0053] Kb is the orifice plate flowmeter coefficient;

[0054] b is the gas concentration correction coefficient;

[0055] h is the static pressure difference on both sides of the orifice plate;

[0056] is the pressure correction coefficient;

[0057] is the temperature correction coefficient.

[0058] The pressure data is obtained through the upper end face pressure tapping hole 222 and the lower end face pressure tapping hole 223, and is transmitted to the differential pressure transmitter 225 through the pressure guide pipe 224 to be converted into an electric signal. The electric signal is transmitted to the orifice monitoring substation through the RS-485 signal line 53 for centralized display.

[0059] Specifically, the metering unit 2 further comprises an explosion-proof junction box 24, a temperature sensor 25 and a pressure sensor 26, and the explosion-proof junction box 24, the temperature sensor 25 and the pressure sensor 26 are all assembled in the interior of the extraction pipe connecting device 21. The probes of the temperature sensor 25 and the pressure sensor 26 are arranged in the interior of the PVC screen pipe 12.

[0060] After the concentration sensor 23, the temperature sensor 25 and the pressure sensor 26 monitor the data, the data is directly transmitted to the orifice monitoring substation through the RS-485 signal line 53 for centralized display.

[0061] The hole sealing unit 3 comprises a lower fixed tray 31, an upper sliding tray 32, a strong compression spring 34 and a hydraulic expansion capsule 35, the lower fixed tray 31 and the upper sliding tray 32 are sleeved and assembled to the outer wall of the PVC extraction pipe 13, the strong compression spring 34 is fixedly installed between the lower fixed tray 31 and the upper sliding tray 32, and the hydraulic expansion capsule 35 is covered outside the strong compression spring 34.

[0062] Specifically, the outer wall of the lower fixed tray 31 and the upper sliding tray 32 is provided with a limiting concave groove 33, and the inner side of the limiting concave groove 33 is assembled with a quick plug 212 and a sealing ring 213, the inner end of the lower fixed tray 31 is fixedly installed with a hollow pipe 36, and the upper sliding tray 32 is movably assembled on the hollow pipe 36.

[0063] The outer wall of the PVC extraction pipe 13 is provided with an annular groove, and the lower fixed tray 31, the upper sliding tray 32, the limiting concave groove 33 and the hollow pipe 36 are located in the annular groove, thereby limiting the position of the hole sealing unit 3 and limiting the movement range of the upper sliding tray 32.

[0064] Specifically, the outer part of the strong compression spring 34 is provided with a telescopic shell 341, the hydraulic expansion capsule 35 is coaxially covered and fixed outside the telescopic shell 341, and the two ends of the hydraulic expansion capsule 35 are respectively sealingly connected with the lower fixed tray 31 and the upper sliding tray 32.

[0065] The strong compression spring 34 is coaxially covered and fixed outside the hollow pipe, and the two ends thereof are connected with the lower fixed tray 31 and the upper sliding tray 32 by means of buckling, and the telescopic shell 341 can be telescopic with the telescopic of the strong compression spring 34.

[0066] The strong compression spring 34 is initially in a free state, at this time, the upper sliding tray 32 is located at the middle position of the annular groove, as the injection pressure becomes larger, the hydraulic expansion capsule 35 begins to expand, the upper sliding tray 32 drives the strong compression spring 34 to begin to slide outward, at this time, the strong compression spring 34 is in a stretched state, once the hydraulic expansion capsule 35 shrinks, the spring will instantaneously release the elastic force, the compression capsule wall expands outward, maintains the sealing force on the borehole wall, keeps the contact pressure of the capsule and the hole wall, and ensures the sealing continuity.

[0067] The liquid injection unit 4 is used for injecting liquid into the hydraulic expansion capsule 35.

[0068] Specifically, the liquid injection unit 4 comprises a hole sealing liquid injection pump 41, a liquid injection pressure gauge 42, a tracheal straight plug 44 and a one-way stop valve 45, the liquid injection pressure gauge 42 is assembled on the hole sealing liquid injection pump 41, the output end of the hole sealing liquid injection pump 41 is assembled with a capsule liquid injection pipe 43, the tracheal straight plug 44 is arranged in the borehole orifice, the one-way stop valve 45 is arranged at the end of the capsule liquid injection pipe 43, and the capsule liquid injection pipe 43 communicates with the hydraulic expansion capsule 35 through the tracheal straight plug 44.

[0069] The one-way stop valve 45 is used to control the flow direction of the liquid injection and maintain the pressure.

[0070] The monitoring substation 5 is used to power the metering unit 2 and receive and display the parameter data monitored by the metering unit 2.

[0071] Specifically, the monitoring substation 5 includes an explosion-proof power supply 51, an armored cable 52, an RS-485 signal line 53, and a digital display meter 54. The explosion-proof power supply 51 provides power to the metering unit 2 through the armored cable 52 arranged in parallel. The gas extraction parameters collected by the metering unit 2 are transmitted to the digital display meter 54 through the RS-485 signal line 53 for display, realizing centralized monitoring and display of parameters.

[0072] The armored cable 52 is used to ensure the explosion-proof safety of the power supply line and the reliability of signal transmission.

[0073] The explosion-proof power supply 51 provides power to the explosion-proof junction box 24 in the metering unit 2 through the armored cable 52. The explosion-proof junction box 24 distributes the power to the corresponding differential pressure transmitter 225 and each sensor, respectively, to power the transmitter and the sensor.

[0074] The hydraulic expansion capsule 35 is provided with a wiring channel 37 and a liquid injection channel 38, respectively. The wiring channel 37 is used to pass through the armored cable 52, and the liquid injection channel 38 is used to communicate with the capsule liquid injection pipe 43.

[0075] Embodiment Two

[0076] A multi-coal seam combined extraction sub-source metering method, which adopts the multi-coal seam combined extraction sub-source metering device of embodiment one, specifically includes the following steps:

[0077] Step 1: First, according to the design, a through-hole drilling is constructed through all coal seams. The drilling is stopped after penetrating the last layer of coal seam by 1m. The first layer of coal seam at the bottom of the hole to the last layer of coal seam at the hole is numbered in turn, respectively M1, M2, …, M N The number of coal seam layers is determined to determine the number N≥2 of metering units 2;

[0078] Step 2: According to the occurrence of coal and rock strata, the extraction pipeline 1 and the metering unit 2 are installed correspondingly. The PVC screen pipe 12 penetrates all coal seams and is connected with the metering unit 2 through the quick connector 212 on the extraction pipe connecting device 21 at the rear of the corresponding coal seam. N sets of metering units 2 are arranged one by one from the rear of the first layer of coal seam at the bottom of the extraction drilling to the rear of the Nth layer of coal seam along the hole direction.

[0079] Step 3, install the sealing unit 3 behind the orifice metering unit 2, after installation, start the sealing liquid injection pump 41, inject liquid into each hydraulic expansion capsule 35 through the capsule liquid injection pipe 43, after the hydraulic expansion capsule 35 expands, push the upper sliding tray 32 to slide, so that the strong compression spring 34 is in a stretched state, after the injection pressure reaches the set threshold, realize the dynamic sealing of the multi-coal seam gas extraction borehole;

[0080] Step 4, after the sealing is completed, power the metering unit 2 through the explosion-proof power supply 51, connect the RS-485 signal line 53 with the digital display meter 54, display the gas extraction parameters of the metering unit 2 through the digital display meter 54, and monitor and record the coal seam gas extraction parameters displayed by the digital display meter 54 in real time;

[0081] Step 5, the multi-coal seam combined extraction sub-source metering pipeline belongs to a series pipeline, the flow rate and concentration data monitored by the metering unit of the first layer coal seam close to the borehole bottom are the real extraction data of the M1 coal seam, the real data of the second layer coal seam M2 is equal to the data monitored by the second metering unit minus the data monitored by the first metering unit, and so on, the real data of the Nth layer coal seam is equal to the data monitored by the Nth metering unit minus the data monitored by the N-1th metering unit, the calculation formula is as follows:

[0082] Q M1 =Q1,η M1 =η1

[0083] Q M2 =Q2-Q1,η M2 =η2-η1

[0084] …

[0085] Q MN =Q N -Q N-1 ,η MN =η N -η N-1

[0086] Wherein:

[0087] Q M1 , Q M2 … Q MN is the gas flow rate of each coal seam;

[0088] η M1 , η M2 … η MN is the gas concentration of each coal seam.

[0089] Example three

[0090] Referring to Figure 5 and Figure 6Different from example one, an explosion-proof battery pack 61 is installed on the metering unit 2, which is used to supply power to the differential pressure transmitter 225 and the concentration sensor 23 on the metering unit 2.

[0091] The flow acquisition device 22 and the concentration sensor 23 on the metering unit 2 are built-in wireless communication modules, and as preferred, the wireless communication module is selected as Zigbee communication.

[0092] The pressure data obtained by the upper and lower end face pressure tapping holes are transmitted to the corresponding differential pressure transmitter 225, which converts the measured differential pressure data into standard electrical signals. The differential pressure signals and the signals monitored by the concentration sensor 23 are transmitted to the wireless communication receiving end 63 in the orifice digital display meter 54 through the wireless communication sending end 62 for centralized display and monitoring.

[0093] According to the gas pressure data and gas concentration data displayed by the digital display meter 54, combined with the flow and concentration calculation formula in example two, the gas flow and gas concentration in each metering unit 2 can be accurately calculated, and the source metering of the gas extraction parameters of each coal seam is realized.

[0094] Example four

[0095] Reference Figure 7 Different from example one and example three, the pressures measured by the upper end face pressure tapping hole 222 and the lower end face pressure tapping hole 223 of the flow acquisition device 22 on the metering unit 2 are directly introduced to the orifice by using a pressure guide pipe 224. A digital differential pressure meter 64 is used to uniformly collect the differential pressure data of each metering unit at the orifice. The digital differential pressure meter 64 is built-in differential pressure transmitter 225, which converts the differential pressure data into electrical signals, and the differential pressure data of each metering unit is displayed on the display screen 65.

[0096] According to the gas pressure data and gas concentration data displayed by the display screen 65, combined with the flow and concentration calculation formula in example two, the gas flow and gas concentration in each metering unit 2 can be accurately calculated, and the source metering of the gas extraction parameters of each coal seam is realized.

[0097] The above is only the preferred embodiment of the present application. For those skilled in the art, according to the idea of the present application, many changes can be made in the specific implementation and application range, as long as these changes do not deviate from the concept of the present application, and they all belong to the protection scope of the present application.

Claims

1. A multi-coal seam combined extraction separate source metering device, characterized in that: Including extraction pipeline, metering unit, sealing unit, liquid injection unit and monitoring substation, the extraction pipeline includes auxiliary ball head, PVC screen pipe and PVC extraction pipe, one end of the PVC screen pipe is equipped with PVC extraction pipe arranged at the drilling hole, the other end of the PVC screen pipe is equipped with auxiliary ball head, and the PVC screen pipe penetrates all coal seams, the PVC screen pipe and the PVC extraction pipe are connected through the metering unit between adjacent PVC screen pipes, the sealing unit is equipped on the outer side of the PVC extraction pipe; The number of the metering unit corresponds to the number of target coal seams, the metering unit includes extraction pipe connecting device, flow acquisition device and concentration sensor, the extraction pipe connecting device is equipped on the outer wall of adjacent PVC screen pipes, and the flow acquisition device and the concentration sensor are both equipped inside the extraction pipe connecting device, the flow acquisition device is equipped between adjacent PVC screen pipes, and the probe of the concentration sensor is arranged on the inner side of the PVC screen pipe. The sealing unit includes lower fixed tray, upper sliding tray, strong compression spring and hydraulic expansion capsule, the lower fixed tray and the upper sliding tray are sleeved and equipped on the outer wall of the PVC extraction pipe, the strong compression spring is fixedly installed between the lower fixed tray and the upper sliding tray, and the hydraulic expansion capsule is covered on the outer side of the strong compression spring. The liquid injection unit is used for injecting liquid into the hydraulic expansion capsule. The monitoring substation is used for power supply of the metering unit and receiving and displaying parameter data monitored by the metering unit. Both ends of the extraction pipe connecting device are provided with recessed grooves, quick plug connectors are fixedly installed in the recessed grooves through loose joint screw wires, the quick plug connectors are sleeved on the outer side of the PVC screen pipe, and sealing rings are arranged between the quick plug connectors and the PVC screen pipe. The flow acquisition device includes a throttling element, an upper end face pressure tapping hole, a lower end face pressure tapping hole, a pressure guide pipe and a differential pressure transmitter, the throttling element is arranged between adjacent PVC screen pipes, the upper end face pressure tapping hole and the lower end face pressure tapping hole are arranged on the PVC screen pipes on both sides of the throttling element, the differential pressure transmitter is fixedly installed on the extraction pipe connecting device, two pressure guide pipes are arranged on the differential pressure transmitter, and the pressure guide pipes are arranged in the upper end face pressure tapping hole and the lower end face pressure tapping hole.

2. The multi-seam combined extraction separate source metering device according to claim 1, characterized in that: The metering unit further includes an explosion-proof junction box, a temperature sensor and a pressure sensor, and the explosion-proof junction box, the temperature sensor and the pressure sensor are all arranged inside the extraction pipe connecting device, and the probes of the temperature sensor and the pressure sensor are arranged on the inner side of the PVC screen pipe.

3. The multi-seam combined extraction sub-source metering device according to claim 1, characterized in that: The outer wall of the lower fixed tray and the upper sliding tray is provided with a limiting recessed groove, and the limiting recessed groove is provided with a quick plug connector and a sealing ring on the inner side, a hollow pipe is fixedly installed on the inner end of the lower fixed tray, and the upper sliding tray is movably arranged on the hollow pipe.

4. The multi-seam combined extraction sub-source metering device according to claim 1, characterized in that: The outer side of the strong compression spring is provided with a telescopic shell, and the hydraulic expansion capsule is coaxially fixedly covered on the outer side of the telescopic shell, and the two ends of the hydraulic expansion capsule are sealingly connected with the lower fixed tray and the upper sliding tray respectively.

5. The multi-seam combined extraction sub-source metering device according to claim 1, characterized in that: The liquid injection unit comprises a hole sealing liquid injection pump, a liquid injection pressure gauge, a gas pipe through plug and a one-way stop valve, the liquid injection pressure gauge is assembled on the hole sealing liquid injection pump, the output end of the hole sealing liquid injection pump is provided with a capsule liquid injection pipe, the gas pipe through plug is arranged in the drilling hole, the one-way stop valve is arranged at the end of the capsule liquid injection pipe, and the capsule liquid injection pipe is communicated with the hydraulic expansion capsule through the gas pipe through plug.

6. The multi-seam combined extraction sub-source metering device according to claim 1, characterized in that: The monitoring substation comprises an explosion-proof power supply, an armored cable, an RS-485 signal line and a digital display meter, the explosion-proof power supply provides power for the metering unit through the armored cable arranged in parallel, and the gas extraction parameters collected by the metering unit are transmitted to the digital display meter through the RS-485 signal line for display.

7. A multi-coal seam combined extraction sub-source metering method, which adopts the multi-coal seam combined extraction sub-source metering device according to any one of claims 1 to 6, and specifically comprises the following steps: Step 1, first according to the design construction of a through all coal seam through layer drilling, drilling through the last layer of coal seam 1m after stop construction, to the hole bottom first layer of coal seam to the hole last layer of coal seam in turn are numbered, respectively, M1, M2... M N , according to the number of coal seam layer to determine the number of groups N≥2; Step 2, according to the coal and rock layer occurrence, install the extraction pipeline and the metering unit, the PVC screen pipe penetrates all the coal seams, and is connected with the metering unit through the quick plug connector on the extraction pipe connecting device after the corresponding coal seam, and N sets of metering units are arranged one by one from the first layer of coal seam after the bottom of the extraction drilling hole to the Nth layer of coal seam after the hole mouth; Step 3, install the hole sealing unit after the hole mouth metering unit, after installation, start the hole sealing liquid injection pump, inject liquid into each hydraulic expansion capsule through the capsule liquid injection pipe, after the hydraulic expansion capsule expands, push the upper sliding tray to slide, so that the strong compression spring is in a stretched state, after the liquid injection pressure reaches the set threshold value, the dynamic sealing of the multi-coal seam gas extraction drilling hole is realized; Step 4, after the hole sealing is completed, the metering unit is powered by the explosion-proof power supply, the RS-485 signal line is connected with the digital display meter, the gas extraction parameters of the metering unit are displayed through the digital display meter, and the gas extraction parameters of each coal seam displayed by the digital display meter are monitored and recorded in real time; Step 5, the multi-coal seam combined extraction sub-source metering pipeline belongs to a series pipeline, the flow and concentration data monitored by the metering unit of the first layer of coal seam close to the bottom of the hole are the real extraction data of the M1 coal seam, the real data of the second layer of coal seam M2 is equal to the data monitored by the second metering unit minus the data monitored by the first metering unit, and so on, the real data of the Nth layer of coal seam is equal to the data monitored by the Nth metering unit minus the data monitored by the N-1th metering unit, and the calculation formula is as follows: Q M1 =Q1,η M1 =η1 Q M2 = Q2 - Q1, η M2 = η2 - η1 …… Q MN =Q N -Q N-1 ,η MN =η N -η N-1 Wherein: Q M1 , Q M2 … Q MN is the gas flow rate of each coal seam; η M1 , η M2 … η MN is the gas concentration of each coal seam.

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