A device and method for measuring residual amount of coal seam gas

Abstract

The present invention provides a device for measuring the amount of residual gas in a coal seam. The device for measuring the amount of residual gas in a coal seam comprises: a coal sample tank device, a gas circulation system, a displacement detection device and a control system. The coal sample in the coal sample tank device is heated by a heater, and the desorbed gas passes through the gas circulation device and flows into the cylinder of the displacement detection device. The PLC controls the rotation of the motor by receiving signals from the temperature sensor and the pressure sensor, and can obtain displacement data. The device for measuring the amount of residual gas in a coal seam of the present invention has a simple structure, high reliability, and fewer pipelines, which simplifies the experimental process, speeds up the gas measurement speed of the coal sample, and facilitates the collection of gas samples to provide them to the chromatograph for analysis, and the device has a long service life. The present invention also provides a method for measuring the amount of residual gas in a coal seam.

Description

Technical Field

[0001] The invention relates to the technical field of coal seam gas content determination, and in particular to a coal seam gas residual amount determination device and determination method. Background Art

[0002] After the coal sample is collected underground, put into the coal sample tank, sealed, and the desorption amount is measured, it needs to be taken to the ground to measure its gas residue. At present, the existing coal sample gas residue test device and method have problems such as water vapor in the collected gas, low accuracy of gas residue test results, complex test system and short service life.

[0003] For example, the invention with patent application number 201510625834.6 discloses an automated coal seam desorbable gas content direct determination device, which realizes the determination of desorbable gas content on the ground and in coal mines respectively through two subsystems, namely, an automated ground gas desorption system and an automated underground gas desorption system; each subsystem adopts a drainage weighing method to determine the desorbable gas content; the automated ground gas desorption system includes an explosion-proof electronic balance, a gas collecting barrel, a water inlet pipeline, an electromagnetic valve, a sensor, etc.; the automated underground gas desorption system includes an explosion-proof electronic balance, a gas collecting barrel, an air inlet pipeline, a drainage pipeline, a sensor, etc.; during the determination process, the gas replaces the water in the gas collecting barrel, causing the mass of the water in the gas collecting barrel to change, and the gas volume can be calculated by the reduced water mass and density formula; the pipelines in the ground device are all controlled by electromagnetic valves, and the ground and underground data are automatically collected by sensors, and the computer terminal of the ground device summarizes and processes them to obtain the final desorbable gas content determination result.

[0004] The utility model with patent application number 201020580897.7 discloses a device for directly measuring gas content, including an underground coal core sampling system for drilling coal cores underground, a coal sample crushing system for crushing coal samples, a gas desorption parameter measuring system for measuring the gas desorption amount of coal samples underground and on the ground, a weighing system for weighing coal samples, an environmental parameter measuring system for measuring ambient temperature and air pressure, and a timing system; the underground coal core sampling system includes a coal seam drilling sampling device and a coal sample barrel, the coal sample crushing system includes a crusher that can crush coal samples, and the environmental parameter measuring system includes a thermometer and an atmospheric pressure gauge.

[0005] The disadvantages of the above two patent applications are that the system is complex and must be filled with water before use. The measurement process is also relatively complicated. Some of the gas dissolves in water, causing errors in the measurement results; if the operation is improper, the collected gas will contain water vapor.

[0006] The invention with patent application number 201210189150.2 discloses a gas residual quantity determination system, which includes a grindable sealed tank, a vacuum sensor, a measuring cylinder, a differential pressure sensor, a degassing bottle and a vacuum pump. The upper edge of the degassing bottle is aligned with the lower part of the measuring cylinder, and the two are connected through a U-shaped tube with a solenoid valve. The lower part of the measuring cylinder is provided with a differential pressure sensor, and the upper part of the measuring cylinder is connected to the vacuum pump through a pipeline, and the pipeline is provided with a solenoid valve. The upper part of the degassing bottle is connected to a four-way, and the other three ports of the four-way are respectively connected to the vacuum sensor and two solenoid valves, one of which is connected to a gas collecting bag, and the other is connected to the grindable sealed tank through a cooling and filtering device. The differential pressure sensor, vacuum sensor, vacuum pump and solenoid valve are all connected to a computer through a data line. The disadvantage of the gas residual quantity determination system is that the system is complex, and water must be filled in the system for use. Salt must be added to the water, which has a corrosive effect on the solenoid valve and the pipeline. A part of the gas dissolves in water, causing errors in the measurement results; if the operation is improper, the collected gas will also contain water vapor. Summary of the invention

[0007] In order to solve the above technical problems, the present invention provides a coal seam gas residual content measuring device with simple structure, strong reliability, few pipelines, no water vapor mixed in the gas, and capable of obtaining high-accuracy coal sample gas residual content test results.

[0008] In order to achieve the above-mentioned object, the present invention adopts the following technical scheme: a coal seam gas residual amount measuring device, comprising: a coal sample tank device, a gas circulation system, a displacement detection device and a control system;

[0009] The coal sample tank device comprises a coal sample tank, an electric heater and a temperature sensor, wherein the electric heater and the temperature sensor are respectively installed outside the coal sample tank, the electric heater is used to heat the coal sample tank, and the temperature sensor is used to detect the temperature of the coal sample tank;

[0010] The gas circulation system comprises a coal sample tank solenoid valve, a cooling and filter, a cooling and filter solenoid valve, and a four-way valve which are sequentially connected through pipelines; the coal sample tank solenoid valve is connected to the coal sample tank device through a pipeline, and the four-way valve is also connected to a pressure sensor, an exhaust port solenoid valve, and a displacement detection device through pipelines respectively, and the other end of the exhaust port solenoid valve is connected to an exhaust pipe, and the end of the exhaust pipe is an exhaust port;

[0011] The displacement detection device includes a cylinder, an electric cylinder, a motor, a motor controller and a reducer. A cylinder air inlet is provided at one end of the cylinder, and the cylinder air inlet is connected to the four-way valve through a pipeline. A cylinder air outlet is provided at the other end of the cylinder. A piston is provided in the cylinder, and the piston is fixed at one end of a piston rod. The other end of the piston rod extends out of the cylinder air outlet and is connected to the electric cylinder. The electric cylinder is also connected to the reducer and the motor in sequence. The motor controller controls the motor, and the electric cylinder is used to drive the piston rod to reciprocate.

[0012] The control system includes a PLC, a control panel, and a host computer. The PLC is interconnected with the control panel and the host computer; the PLC is respectively connected with an electric heater, a temperature sensor, a coal sample tank solenoid valve, a cooling and filter solenoid valve, an exhaust port solenoid valve, a pressure sensor, and a motor controller; the PLC receives signals from the temperature sensor and the pressure sensor, and controls the operation of the electric heater, the coal sample tank solenoid valve, the cooling and filter solenoid valve, the exhaust port solenoid valve, and the motor controller.

[0013] Furthermore, the motor is a DC servo motor, the DC servo motor is equipped with an encoder, the encoder is connected to a PLC, and the PLC receives a signal from the encoder.

[0014] Furthermore, the displacement detection device also includes a moving slider and a displacement sensor. The moving slider is fixed on the piston rod, and a through hole parallel to the piston rod is arranged on the moving slider; the slide rod of the displacement sensor is arranged in a parallel position relative to the piston rod, and the moving slider is mounted on the slide rod of the displacement sensor through the through hole, and can move up and down relative to the slide rod; the displacement sensor is connected to the PLC, and the PLC receives the displacement data signal emitted by the displacement sensor.

[0015] Furthermore, the displacement sensor is a magnetostrictive displacement sensor.

[0016] The present invention also discloses a method for determining the residual amount of coal seam gas, comprising the following steps:

[0017] Step 1, put the coal sample into the coal sample tank, close the coal sample tank solenoid valve through the control panel, and connect the coal sample tank with the coal sample tank solenoid valve pipeline;

[0018] Step 2: The control system controls the electric heater to heat the coal sample tank. When the temperature in the coal sample tank reaches a preset temperature range and then maintains a constant temperature, the cooling and filter solenoid valves are closed, the exhaust port solenoid valve is opened, and the motor is started to push the piston in the cylinder to the cylinder air inlet end, and the gas in the cylinder is discharged through the exhaust port.

[0019] Step 3, the control system closes the exhaust port solenoid valve, opens the coal sample tank solenoid valve and the cooling and filter solenoid valves, and then the motor pulls the piston rod to move toward the cylinder outlet end to form a vacuum in the cylinder, thereby allowing the gas in the coal sample tank to enter the cylinder; when the piston rod is fully extended out of the cylinder and reaches the limited position of the piston, the motor controller controls the motor to stop; when the motor stop time reaches the preset time, the motor controller controls the motor to slowly push the piston rod toward the cylinder inlet end, and when the pressure sensor data is the preset pressure, the motor stops, and the PLC obtains the displacement data of the piston from the limited position to the preset pressure position, calculates the gas residual amount based on the displacement data and stores it in the host computer, which can be retrieved and / or output at any time;

[0020] Step 4, close the cooling and filter solenoid valves, open the exhaust port solenoid valve, and the gas is discharged from the exhaust port to the air bag or chromatograph.

[0021] Furthermore, the displacement data of the piston from the limited position to the preset pressure position is obtained by an encoder configured by the DC servo motor.

[0022] Furthermore, the displacement data of the piston from the limited position to the preset pressure position is obtained by a displacement sensor.

[0023] Furthermore, the preset temperature is 50° C. to 90° C., and the preset time is 5 min to 5 h.

[0024] Furthermore, the preset pressure is 0.1 MPa.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The coal seam gas residual amount measuring device of the present invention has a simple structure, high reliability, and few pipelines, which simplifies the experimental process and speeds up the gas measurement speed of coal samples.

[0027] 2. It is not necessary to fill the system with water to prevent some gas components (such as carbon dioxide, hydrogen sulfide, etc.) from dissolving in water, which makes the gas undetectable or the measured value too low. It completely avoids the mixing of water vapor in the collected gas, which causes the wrong judgment of the gas composition, and avoids the reading error caused by manual reading of the water column height, which greatly reduces the system error. There is no liquid corrosion to the system pipeline, solenoid valve, and other components, which makes the device highly reliable and has a long service life.

[0028] 3. Since the system has no vacuum pump, the noise is low; automatic control is realized, and the experimental process is almost unattended, which greatly reduces the labor intensity of the staff.

[0029] 4. The device can be used to measure the residual gas amount of coal samples before crushing, and can also be used to measure the residual gas amount of coal samples after crushing. It is also convenient for collecting gas samples so as to provide them to the chromatograph for analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is the principle diagram of the coal seam gas residual quantity measuring device with the motor equipped with an encoder;

[0031] Figure 2 This is the control system principle diagram of the coal seam gas residual quantity measuring device with the motor equipped with an encoder;

[0032] Figure 3 This is the principle diagram of the coal seam gas residual quantity measuring device with displacement sensor;

[0033] Figure 4 It is a schematic diagram of the control system of a coal seam gas residual quantity measuring device with a displacement sensor.

[0034] In the figure: 1. coal sample tank, 2. coal sample tank solenoid valve, 3. cooling and filter, 4. cooling and filter solenoid valve, 5. pressure sensor, 6. exhaust port solenoid valve, 7. exhaust port, 8. cylinder, 9. cylinder air inlet, 10. piston, 11. piston rod, 12. four-way, 13. cylinder air outlet, 15. electric cylinder, 16. motor, 17. reducer, 18. encoder, 19. motor controller, 21. PLC, 30. moving slider, 31. displacement sensor, 100. temperature sensor, 101. electric heater, 102. control panel, 103. shell, 200. host computer. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] like Figure 1 and Figure 2 As shown, a coal seam gas residual amount measuring device of the present invention comprises: a coal sample tank device, a gas circulation system, a displacement detection device and a control system.

[0037] The coal sample tank device includes a coal sample tank 1, an electric heater 101 and a temperature sensor 100. The electric heater 101 and the temperature sensor 100 are respectively installed on the outside of the coal sample tank 1. The electric heater 101 is used to heat the coal sample tank 1, and the temperature sensor 100 is used to detect the temperature of the coal sample tank 1. When detecting the residual amount of coal seam gas, after the coal sample is collected underground, loaded into the coal sample tank 1, sealed, and the desorption amount is measured, the un-crushed or crushed coal sample is placed in the coal sample tank 1. When testing, heating the coal sample tank 1 can speed up the process of gas desorption in the coal sample, thereby speeding up the gas measurement speed of the coal sample.

[0038] The gas circulation system includes a coal sample tank solenoid valve 2, a cooling and filter 3, a cooling and filter solenoid valve 4, and a four-way valve 12 which are sequentially connected through pipelines; the coal sample tank solenoid valve 2 is connected to the coal sample tank 1 device through pipelines, and the four-way valve 12 is also connected to the pressure sensor 5, the exhaust port solenoid valve 6, and the displacement detection device through pipelines, and the other end of the exhaust port solenoid valve 6 is connected to the exhaust pipe through the pipeline, and the end of the exhaust pipe is the exhaust port 7. The entire gas circulation system is connected by a sealed pipeline, wherein when the coal sample tank solenoid valve 2 is opened, the gas flows through the cooling and filter 3 through the pipeline; when the cooling and filter solenoid valve 4 is opened, the gas enters the four-way valve 12; when the exhaust port solenoid valve 6 is opened, the gas flows out from the exhaust port 7 at the end of the exhaust pipe through the exhaust pipe.

[0039] The displacement detection device includes a cylinder 8, an electric cylinder 15, a motor 16, a motor controller 19 and a reducer 17. A cylinder air inlet 9 is provided at one end of the cylinder 8, and the cylinder air inlet 9 is connected to a four-way 12 through a pipeline. A cylinder air outlet 13 is provided at the other end of the cylinder 8. A piston 10 is provided in the cylinder 8, and the piston 10 is fixed at one end of a piston rod 11. The other end of the piston rod 11 extends out of the cylinder air outlet 13 and is connected to the electric cylinder 15. The electric cylinder 15 is also connected to the reducer 17 and the motor 16 in sequence. The motor controller 19 controls the motor 16, and the electric cylinder 15 is used to drive the piston rod 11 to reciprocate. Gas flows into the cylinder body of the cylinder 8 through the four-way 12, the pipeline, and the cylinder air inlet 9. When the motor 16 rotates, the electric cylinder 15 is driven by the reducer 17 to pull the piston rod 11 to move toward the cylinder outlet 13 end, and the air pressure in the cylinder 8 will become smaller and smaller; when the motor 16 rotates in the opposite direction, the electric cylinder 15 pushes the piston rod 11 to move toward the cylinder inlet 9 end. At this time, the exhaust port solenoid valve 6 is closed, and the gas pressure in the cylinder 8 becomes larger and larger. When the gas pressure reaches a predetermined value, the displacement data of the piston 10 can be detected. The entire detection device does not need to be filled with water, water vapor will not be generated, and gas will not be dissolved in water to affect the accuracy of the detection result.

[0040] The control system includes PLC21, control panel 102, and host computer 200. PLC21 is connected to control panel 102 and host computer 200; PLC21 is connected to electric heater 101, temperature sensor 100, coal sample tank solenoid valve 2, cooling and filter solenoid valve 4, exhaust port solenoid valve 6, pressure sensor 5, and motor controller 19 respectively; PLC21 receives signals from temperature sensor 100 and pressure sensor 5 to control the operation of electric heater 101, coal sample tank solenoid valve 2, cooling and filter solenoid valve 4, exhaust port solenoid valve 6, and motor controller 19. Automatic control is realized, and the experimental process is almost unattended, which greatly reduces the labor intensity of the staff.

[0041] Specifically, the control screen 102 is a touch screen.

[0042] Specifically, the coal sample tank 1 device further includes a shell 103, and the coal sample tank 1, the electric heater 101 and the temperature sensor 100 are arranged in the inner cavity of the shell 103. A heat preservation layer is arranged on the shell 103 to keep the coal sample tank 1 warm. When the electric heater 101 heats the coal sample tank 1, the heat loss is reduced, the electric energy is saved, and the staff is prevented from being scalded, thereby ensuring safety.

[0043] Specifically, the motor 16 is a DC servo motor, and the DC servo motor is equipped with an encoder 18, which is connected to the PLC 21, and the PLC 21 receives the signal from the encoder 18. According to the motor 16 running revolution data signal from the encoder 18, the displacement data of the piston rod 11 is calculated.

[0044] Specifically, Figure 3 and Figure 4 As shown, the motor 16 is a DC servo motor, but is not equipped with an encoder 18; then according to the coal seam gas residual amount measuring device of the present invention, the displacement detection device also includes a moving slider 30 and a displacement sensor 31, the moving slider 30 is fixed on the piston rod 11, and a through hole parallel to the piston rod 11 is set on the moving slider 30. When the electric cylinder 15 drives the piston rod 11 to move, the moving slider 30 on the piston rod 11 also moves. The slide bar of the displacement sensor 31 is set in a parallel position relative to the piston rod 11, and the bracket fixes the displacement sensor 31 on one side of the cylinder 8. The bracket is set according to the actual situation of the equipment site, for example, it can be set on the base, body of the motor 16, or on the outside of the cylinder body of the cylinder 8. The moving slider 30 is mounted on the slide bar of the displacement sensor 31 through the through hole, and can always move up and down smoothly relative to the slide bar. The displacement range of the piston rod 11 will not exceed the range of the displacement sensor 31. The displacement sensor 31 is connected to the PLC21, and the PLC21 receives the displacement data signal sent by the displacement sensor 31.

[0045] Specifically, the displacement sensor 31 is a magnetostrictive displacement sensor.

[0046] like Figure 1 and Figure 2 As shown, the present invention also discloses a method for measuring the amount of residual coal seam gas, which can be applied to the above-disclosed device for measuring the amount of residual coal seam gas, and the method comprises the following steps:

[0047] Step 1, put the coal sample into the coal sample tank 1, close the coal sample tank solenoid valve 2 through the control panel 102, and connect the coal sample tank 1 with the coal sample tank solenoid valve 2 through a pipeline;

[0048] Step 2, the control system controls the electric heater 101 to heat the coal sample tank 1. When the temperature in the coal sample tank 1 reaches a preset temperature range and then maintains a constant temperature, the cooling and filter solenoid valve 4 is closed, the exhaust port solenoid valve 6 is opened, and the motor 16 is started to push the piston 10 in the cylinder 8 to the end of the cylinder air inlet 9, and the gas in the cylinder 8 is discharged through the exhaust port 7;

[0049] Step 3, the control system closes the exhaust port solenoid valve 6, opens the coal sample tank solenoid valve 2 and the cooling and filter solenoid valve 4, and then the motor 16 pulls the piston rod 11 to move toward the cylinder outlet 13 end, so that a vacuum is formed in the cylinder 8, and then the gas in the coal sample tank 1 enters the cylinder 8; when the piston rod 11 is fully extended out of the cylinder 8 and reaches the limited position of the piston 10, the motor controller 19 controls the motor 16 to stop; when the motor 16 stop time reaches the preset time, the motor controller 19 controls the motor 16 to slowly push the piston rod 11 toward the cylinder inlet 9 end, and when the pressure sensor 5 data is the preset pressure, the motor 16 stops and obtains the displacement data of the piston 10 from the limited position to the preset pressure position, and the displacement data of the piston 10 from the limited position to the preset pressure position is multiplied by the cross-sectional area of ​​the piston 10 to obtain the gas residual amount; the gas residual amount calculated according to the displacement data is stored in the host computer 200, and can be retrieved and / or output at any time;

[0050] Step 4, close the cooling and filter solenoid valve 4, open the exhaust port solenoid valve 6, the gas is discharged from the exhaust port 7 to the air bag, and then the air bag is connected to the chromatograph to analyze the gas; or the gas is directly discharged into the chromatograph and the gas analysis is directly performed.

[0051] Specifically, when the motor 16 is a DC servo motor and is equipped with an encoder 18, the displacement data of the piston 10 from a limited position to a preset pressure position is calculated based on the data signal provided by the encoder 18 equipped with the DC servo motor.

[0052] Specifically, Figure 3 and Figure 4As shown, when the motor 16 is a DC servo motor but is not equipped with an encoder 18 , the displacement data of the piston 10 from a limited position to a preset pressure position is obtained through a data signal sent by the displacement sensor 31 .

[0053] Specifically, the preset temperature is 50° C. to 90° C., the preset time is 5 min to 5 h, and the preset pressure is 0.1 Mpa.

[0054] Embodiment 1

[0055] like Figure 1 and Figure 2 As shown, a coal seam gas residual amount measuring device comprises a coal sample tank 1, a coal sample tank solenoid valve 2, a cooling and filter 3, a cooling and filter solenoid valve 4, and a four-way 12 which are sequentially connected by pipelines; the four-way 12 is also connected to a pressure sensor 5, an exhaust port solenoid valve 6, and a cylinder air inlet 9 through pipelines, the other end of the exhaust port solenoid valve 6 is connected to an exhaust pipe, and the end of the exhaust pipe is an exhaust port 7; the cylinder air inlet 9 is connected to a cylinder 8 by a pipeline, a piston 10 is arranged in the cylinder 8, and a cylinder air outlet 13 is arranged at the other end of the cylinder 8, and the piston 10 is fixed at On the piston rod 11, the piston rod 11 extends out of the cylinder air outlet 13 and is connected to the electric cylinder 15, the electric cylinder 15 is driven by a DC servo motor, and an electric heater 101 and a temperature sensor 100 are arranged on the outside of the coal sample tank 1; it also includes a control system, the control system is based on PLC21 and is respectively connected to the touch screen, electric heater 101, temperature sensor 100, coal sample tank solenoid valve 2, cooling and filter solenoid valve 4, exhaust port solenoid valve 6, pressure sensor 5, and motor controller 19; PLC21 is also interconnected with the host computer 200.

[0056] Wherein: the DC servo motor is equipped with an encoder 18, the encoder 18 is connected to the PLC 21, the PLC 21 receives the signal sent by the encoder 18, and the DC servo motor is connected to the reducer 17 to drive the electric cylinder 15 to perform reciprocating motion.

[0057] Embodiment 2

[0058] like Figure 3 and Figure 4 As shown, the difference from the first embodiment is that when the DC servo motor is not equipped with an encoder 18, a movable slider 30 is fixed on the piston rod 11, and a through hole parallel to the piston rod 11 is provided on the movable slider 30; the movable slider 30 is sleeved on the slide bar of the displacement sensor 31 through the through hole, and the displacement sensor 31 is fixed on the body. The DC servo motor is connected to the reducer 17, and the displacement sensor 31 is a magnetostrictive displacement sensor 31.

[0059] Embodiment 3

[0060] like Figure 1 and Figure 2As shown, a method for measuring the residual amount of coal seam gas is implemented by a control system with PLC21 as the core after programming, including:

[0061] Step 1, first transport the coal sample tank 1 used for measuring gas content in the coal mine to the laboratory, close the coal sample tank solenoid valve 2 through the touch screen, and connect the coal sample tank 1 pipeline to the coal sample tank solenoid valve 2.

[0062] Step 2, heat the coal sample tank 1 through the electric heater 101, maintain a constant temperature when the temperature sensor 100 reaches 90°C, close the cooling and filter solenoid valve 4, open the exhaust port solenoid valve 6, and use the DC servo motor to push the piston rod 11 of the cylinder 8 to the end of the cylinder air inlet 9, and discharge the gas in the cylinder 8 through the exhaust port 7.

[0063] Step 3, close the exhaust port solenoid valve 6, open the coal sample tank solenoid valve 2 and the cooling and filter solenoid valve 4, and then pull the piston rod 11 outward by the DC servo motor to form a vacuum in the cylinder 8, so that the gas in the coal sample tank 1 enters the cylinder 8. When the piston rod 11 is fully extended out of the cylinder 8 and reaches the limited position of the piston 10, the motor controller 19 controls the DC servo motor to stop. After the DC servo motor stops for 2 hours, the piston rod 11 is slowly pushed inward by the DC servo motor. When the data of the pressure sensor 5 is 0.1Mpa, the DC servo motor stops and obtains the displacement data; wherein, the DC servo motor is equipped with an encoder 18 that provides a displacement data signal.

[0064] Step 4, close the cooling and filter solenoid valve 4, open the exhaust port solenoid valve 6, and the gas is discharged from the exhaust port 7 to the air bag or chromatograph. At the same time, the gas residual amount is calculated based on the displacement data and stored in the host computer 200 for review and / or output at any time.

[0065] Embodiment 4

[0066] like Figure 3 and Figure 4As shown, the difference from the third embodiment is that when the DC servo motor is not equipped with an encoder 18, step 3 is: after closing the exhaust port solenoid valve 6, opening the coal sample tank solenoid valve 2 and the cooling and filter solenoid valve 4, the DC servo motor pulls the piston rod 11 outward to form a vacuum in the cylinder 8, so that the gas in the coal sample tank 1 enters the cylinder 8. When the piston rod 11 is fully extended out of the cylinder 8 and reaches the limited position of the piston 10, the motor controller 19 controls the motor 16 to stop. After the DC servo motor stops for 30 minutes, the DC servo motor slowly pushes the piston rod 11 inward. When the data of the pressure sensor 5 is 0.1Mpa, the DC servo motor stops and obtains the displacement data from the displacement sensor 31, closes the cooling and filter solenoid valve 4, opens the exhaust port solenoid valve 6, and the gas is discharged from the exhaust port 7 to the air bag or chromatograph. At the same time, the gas residual amount is calculated according to the displacement data and stored in the host computer 200, which can be retrieved or / and output at any time.

[0067] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A device for measuring the residual amount of coal seam gas, characterized in that: include: Coal sample tank device, gas circulation system, displacement detection device and control system; The coal sample tank device comprises a coal sample tank, an electric heater and a temperature sensor, wherein the electric heater and the temperature sensor are respectively installed outside the coal sample tank, the electric heater is used to heat the coal sample tank, and the temperature sensor is used to detect the temperature of the coal sample tank; The gas circulation system comprises a coal sample tank solenoid valve, a cooling and filter, a cooling and filter solenoid valve, and a four-way valve which are sequentially connected through pipelines; the coal sample tank solenoid valve is connected to the coal sample tank device through a pipeline, and the four-way valve is also connected to a pressure sensor, an exhaust port solenoid valve, and a displacement detection device through pipelines respectively, and the other end of the exhaust port solenoid valve is connected to an exhaust pipe, and the end of the exhaust pipe is an exhaust port; The displacement detection device includes a cylinder, an electric cylinder, a motor, a motor controller and a reducer. A cylinder air inlet is provided at one end of the cylinder, and the cylinder air inlet is connected to the four-way valve through a pipeline. A cylinder air outlet is provided at the other end of the cylinder. A piston is provided in the cylinder, and the piston is fixed at one end of a piston rod. The other end of the piston rod extends out of the cylinder air outlet and is connected to the electric cylinder. The electric cylinder is also connected to the reducer and the motor in sequence. The motor controller controls the motor, and the electric cylinder is used to drive the piston rod to reciprocate. The control system includes a PLC, a control panel and a host computer, wherein the PLC is interconnected with the control panel and the host computer; the PLC is respectively connected with an electric heater, a temperature sensor, a coal sample tank solenoid valve, a cooling and filter solenoid valve, an exhaust port solenoid valve, a pressure sensor and a motor controller; the PLC receives signals from the temperature sensor and the pressure sensor to control the electric heater, the coal sample tank solenoid valve, the cooling and filter solenoid valve, the exhaust port solenoid valve and the motor controller to work; The motor is a DC servo motor, the DC servo motor is equipped with an encoder, the encoder is connected to a PLC, and the PLC receives a signal from the encoder; The displacement detection device also includes a moving slider and a displacement sensor. The moving slider is fixed on the piston rod, and a through hole parallel to the piston rod is arranged on the moving slider. The slide bar of the displacement sensor is arranged in a parallel position relative to the piston rod, and the moving slider is mounted on the slide bar of the displacement sensor through the through hole, and can move up and down relative to the slide bar. The displacement sensor is connected to the PLC, and the PLC receives the displacement data signal sent by the displacement sensor.

2. The device for measuring the residual amount of coal seam gas according to claim 1, characterized in that: The displacement sensor is a magnetostrictive displacement sensor.

3. A method for measuring the amount of residual coal seam gas based on the device for measuring the amount of residual coal seam gas according to claim 1, characterized in that: The steps include: Step 1, put the coal sample into the coal sample tank, close the coal sample tank solenoid valve through the control panel, and connect the coal sample tank with the coal sample tank solenoid valve pipeline; Step 2: The control system controls the electric heater to heat the coal sample tank. When the temperature in the coal sample tank reaches a preset temperature range and then maintains a constant temperature, the cooling and filter solenoid valves are closed, the exhaust port solenoid valve is opened, and the motor is started to push the piston in the cylinder to the cylinder air inlet end, and the gas in the cylinder is discharged through the exhaust port. Step 3, the control system closes the exhaust port solenoid valve, opens the coal sample tank solenoid valve and the cooling and filter solenoid valves, and then the motor pulls the piston rod to move toward the cylinder outlet end to form a vacuum in the cylinder, thereby allowing the gas in the coal sample tank to enter the cylinder; when the piston rod is fully extended out of the cylinder and reaches the limited position of the piston, the motor controller controls the motor to stop; when the motor stop time reaches the preset time, the motor controller controls the motor to slowly push the piston rod toward the cylinder inlet end, and when the pressure sensor data is the preset pressure, the motor stops, and the PLC obtains the displacement data of the piston from the limited position to the preset pressure position, calculates the gas residual amount based on the displacement data and stores it in the host computer, which can be retrieved and / or output at any time; Step 4, close the cooling and filter solenoid valves, open the exhaust port solenoid valve, and the gas is discharged from the exhaust port to the air bag or chromatograph.

4. The method for measuring the residual amount of coal seam gas according to any one of claim 3, characterized in that: The preset temperature is 50° C. to 90° C., and the preset time is 5 min to 5 h.

5. The method for measuring the residual amount of coal seam gas according to any one of claim 3, characterized in that: The preset pressure is 0.1 MPa.

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