A downhole gas collector

Abstract

The present invention discloses a downhole gas collector, comprising a plate body and a gas channel arranged in the plate body, a plurality of gas parameter detection sensors are arranged on the gas channel, the gas channel comprises a plurality of holes arranged at intervals, adjacent holes are connected through a plurality of open chambers, a sealing ring is installed in each open chamber, and a channel for gas to enter and exit from the side is enclosed by the sensing end face of the gas parameter detection sensor and the inner wall of the open chamber; a frustum-shaped baffle is arranged in each open chamber, the bottom end of the frustum-shaped baffle is connected to the bottom wall of the open chamber, and the top of the frustum-shaped baffle is lower than the top wall of the hole and higher than the axis of the hole. The present invention can not only realize the accurate detection of multiple indicators by using a gas collector as small as possible, but also completely avoid the gas being trapped in the space / gas chamber below the sensor, and also has the advantages of fast response time and good sensitivity.

Description

Technical Field

[0001] The invention relates to an instrument for detecting underground gas component concentration, and in particular to an underground gas collector. Background Art

[0002] In the process of underground gas component concentration detection, ensuring rapid response of detection has always been the focus and difficulty of research in this field. At present, there are two main aspects to ensure rapid response of detection: one is to optimize signal conversion, such as the underground explosion gas detector for mine safety disclosed in document CN201203580Y, which is mainly composed of a light source, an absorption chamber, a detector, a microprocessor, and an amplifier. The light source, the absorption chamber and the detector are connected to form a gas detection sensor, and the signal amplifier is respectively connected to the detector A / D converter, and the CPU microprocessor is respectively connected to the pulse drive, A / D converter, LCD and RS232 interface. This scheme uses the change of the absorption rate of gas to light of a specific wavelength with the concentration to detect the concentration of gas in the environment, and finally achieves the effect of fast response time; the second is to optimize the sensor / collector structure, such as the gas detection chamber disclosed in document CN201828541U, It includes a sealing block and a sensor with a hole-shaped air chamber vertically provided, and a gas channel connected to the air chamber horizontally provided on the sealing block. Gas connectors are connected to both ends of the gas channel. The sensor is installed above the air chamber. An air guide plate is provided in the air chamber. The cross-section of the air guide plate is cross-shaped, so that after the airflow enters the gas channel, it changes direction when it encounters the air guide plate and flows toward the sensor, and then returns from the sensor surface and flows out from the other end of the airflow channel. This solution changes the direction of the airflow so that the airflow flows directly to the sensor, so that the sensor will not have the problem of slow response and instability. However, this solution is only suitable for occasions with large air flow and for installing a single sensor. The gas connector, sealing body, air guide plate, and air chamber together constitute a gas collector, which is a sensor configured with a gas collector, and it is easy for gas to be retained in the space below the sensor.

[0003] When actually detecting the composition and concentration of underground gas, since multiple sensors are needed to detect the concentration of gas, the above-mentioned solution has many disadvantages, such as high cost of the required instruments and large space occupied. In this regard, ideally, the smallest underground gas collector possible should be used to achieve accurate detection of multiple indicators, but currently no gas collector can meet this requirement. Summary of the invention

[0004] The object of the present invention is to provide a downhole gas collector, which can at least realize accurate detection of multiple indicators using the smallest possible downhole gas collector, while avoiding gas retention in the space / gas chamber below the sensor.

[0005] To achieve the aforementioned purpose, the present invention provides a downhole gas collector, comprising a plate body and a gas channel arranged in the plate body, a plurality of gas parameter detection sensors are arranged on the gas channel, a plurality of probes of each gas parameter detection sensor are arranged circumferentially and are located on the same circumference of the sensing end face, and is characterized in that: the gas channel comprises a plurality of spaced-apart channels, adjacent channels are connected through a plurality of open chambers, the inner wall of each open chamber has a step, an annular groove for installing a sealing ring is arranged on the step, the gas parameter detection sensor is installed at the step, the axis of each open chamber is perpendicular to the sensing end of the gas parameter detection sensor, the sensing end face of the gas parameter detection sensor and the inner wall of the open chamber jointly enclose a channel for gas entry and exit from the side; a frustum-shaped baffle body is arranged in each open chamber, the bottom end of the frustum-shaped baffle body is connected to the bottom wall of the open chamber, and the top of the frustum-shaped baffle body is lower than the top wall of the channel and higher than the axis of the channel.

[0006] In order to further improve the accuracy and sensitivity of the detection results of each sensor, the top of the frustum-shaped baffle body is a hemispherical structure.

[0007] As a preferred solution, the angle between the inclined wall of the frustum-shaped baffle body and the axis of the frustum-shaped baffle body is 42-60°.

[0008] In order to further improve the accuracy and sensitivity of the detection results of each sensor, the cross section of the channel is elliptical.

[0009] As a more preferred solution, the diameter of the hemispherical structure at the top of the frustum-shaped baffle body is smaller than the cross-sectional length of the channel.

[0010] To ensure the accuracy and sensitivity of the detection results of the last sensor, ribs are arranged horizontally in the last open cavity, and the bottom wall of the ribs is higher than the top of the conical baffle in the open cavity or the bottom wall of the ribs is flush with the top of the conical baffle in the open cavity, and along the gas flow direction, there is a gap between the ribs and the conical baffle in the open cavity, and there is also a gap between the top wall of the ribs and the sensing end face of the gas parameter detection sensor.

[0011] In order to further reduce the resistance of the gas in the gas channel and prevent the formation of backflow, the hole is directly opposite to the arc-shaped side wall of the inner wall of the open cavity.

[0012] As a preferred embodiment, the gas channel includes an air intake channel, a first open cavity, a first channel, a second open cavity, a second channel, a third open cavity, a third channel, a fourth open cavity, a fourth channel, a fifth open cavity, and an exhaust channel connected in sequence.

[0013] As a preferred solution, the plate body is made by 3D printing technology, and its material is engineering plastic.

[0014] In order to increase the service life of the gas collector, the bottom wall of the plate body is fixed on the bracket, and a pressure plate is arranged above the plate body. The pressure plate is connected to the plate body through fasteners and presses the gas parameter detection sensor.

[0015] Beneficial effects:

[0016] 1. The solution of the present invention can not only realize the accurate detection of multiple indicators by using the smallest possible gas collector, but also can install at least five gas parameter detection sensors on a 20mm*15mm gas collector, and can completely avoid gas stagnation in the space / gas chamber below the sensor;

[0017] 2. The solution of the present invention has high detection sensitivity and can achieve response in a short time;

[0018] 3. The gas channel in the gas collector provided by the present invention has no joints, the inner wall roughness of the entire gas channel is uniform, and the resistance of the gas flowing therein is small;

[0019] 4. The gas collector provided by the present invention has a small size, a simple structure and a low manufacturing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the external structure of the downhole gas collector in the embodiment;

[0021] Figure 2 Schematic diagram of the external structure of the downhole gas collector in the embodiment (excluding the pressure plate 6);

[0022] Figure 3 This is a cross-sectional schematic diagram of a downhole gas collector in an embodiment;

[0023] Figure 4 Schematic diagram of the external structure of the plate body of the downhole gas collector in the embodiment;

[0024] Figure 5 Schematic diagram of the cross section of a plate body of a downhole gas collector in an embodiment;

[0025] Figure 6 for Figure 4 Enlarged view of area A in the middle. DETAILED DESCRIPTION

[0026] The present invention will be further described below in conjunction with the accompanying drawings and embodiments. Example

[0027] like Figures 1 to 6As shown, a downhole gas collector includes a plate body 1 and a gas channel arranged in the plate body 1. Five gas parameter detection sensors are arranged on the gas channel to detect the concentration of each gas component. The probes of each gas parameter detection sensor are arranged in a circumferential direction and are located on the same circumference of the sensing end face. Among them, the gas channel includes a plurality of holes 4 arranged at intervals, and the adjacent holes 4 are connected through a plurality of open chambers. The inner wall of each open chamber has a step 2, and an annular groove 9 for installing a sealing ring 26 is arranged on the step 2. The gas parameter detection sensor is installed at the step 2. The axis of each open chamber is perpendicular to the sensing end of the gas parameter detection sensor. The sensing end face of the gas parameter detection sensor and the inner wall of the open chamber jointly enclose a channel for gas to enter and exit from the side; a frustum-shaped baffle 3 is arranged in each open chamber, and the bottom end of the frustum-shaped baffle 3 is connected to the bottom wall of the open chamber, and the top of the frustum-shaped baffle 3 is lower than the top wall of the hole 4 and higher than the axis of the hole 4.

[0028] In this embodiment, the top of the frustum-shaped blocker 3 is a hemispherical structure; the angle between the inclined wall of the frustum-shaped blocker 3 and the axis of the frustum-shaped blocker 3 is 52°; the cross section of the channel 4 is elliptical; the diameter of the hemispherical structure at the top of the frustum-shaped blocker 3 is smaller than the cross-sectional length of the channel 4. In the application scheme of this embodiment, the radial cross-sectional length of the channel 4 is 6 mm and the height is 3 mm, the diameter of the hemispherical structure at the top of the frustum-shaped blocker 3 is 2 mm, and the height of the frustum-shaped blocker 3 is 2.5 mm.

[0029] In this embodiment, a rib 5 is transversely arranged in the last open cavity, with both ends of the rib 5 connected. The bottom wall of the rib 5 is higher than the top of the conical baffle 3 in the open cavity (the height difference is 2 mm), and along the gas flow direction, there is a gap of 10 mm between the rib 4 and the conical baffle 3 in the open cavity, and there is a gap of 3 mm between the top wall of the rib 5 and the sensing end face of the gas parameter detection sensor.

[0030] In this embodiment, the hole 4 is directly opposite to the arc-shaped side wall of the inner wall of the open cavity; the gas channel includes an intake channel 10, a first open cavity 11, a first hole 12, a second open cavity 13, a second hole 14, a third open cavity 15, a third hole 16, a fourth open cavity 17, a fourth hole 18, a fifth open cavity 19, and an exhaust channel 20 connected in sequence. Among them, the cross-sections of the first open cavity 11, the second open cavity 13, the fourth open cavity 17, and the fifth open cavity 19 are all circular, and the cross-section of the third open cavity 15 is hexagonal, and the wall surface corresponding to one side is an arc-shaped wall surface. Among them, a carbon dioxide sensor 21 is installed in the first open cavity 11, an oxygen sensor 22 is installed in the second open cavity 13, a methane sensor 23 is installed in the third open cavity 15, a carbon monoxide sensor 21 is installed in the fourth open cavity 17, and an ethylene sensor 25 is installed in the fifth open cavity 19.

[0031] In this embodiment, the plate body 1 is made of engineering plastic by using a 3D printing process. The plate body 1 , the frustum-shaped baffle body 3 , and the ribs 5 are integrally formed.

[0032] In this embodiment, the bottom wall of the plate body 1 is fixed on the bracket 8, and a pressing plate 6 is arranged above the plate body 1. The pressing plate 6 is connected to the plate body 1 through a fastener 7 and presses the gas parameter detection sensor.

[0033] Comparative Example

[0034] The main structure and dimensions of the underground gas collector refer to the aforementioned embodiment, and the difference between the underground gas collector and the aforementioned embodiment lies in that each open cavity does not contain a frustum-shaped baffle 3, and the last open cavity does not have a rib 5.

[0035] Referring to the specifications of AQ1052-2008 "General Technical Requirements for Carbon Dioxide Sensors for Coal Mines", AQ6211-2008 "Non-dispersive Infrared Methane Sensors for Coal Mines", AQ6205-2006 "Electrochemical Carbon Monoxide Sensors for Coal Mines", AQ 447-1995 "Technical Requirements for Electrochemical Oxygen Sensors for Coal Mines", and NBT10546-2021 "Ethylene Sensors for Coal Mines", the sensor response time of the downhole gas collectors in the embodiments and comparative embodiments was tested.

[0036] Carbon dioxide detection: When the gas flow rate is 500ml / min, carbon dioxide of a specific concentration (2.5% volume percentage concentration) is passed into the gas collector in the embodiment, and the results show that the response time of the carbon dioxide sensor is 19S; when the gas flow rate is 300ml / min, carbon dioxide of a specific concentration (2.5% volume percentage concentration) is passed into the gas collector in the embodiment, and the results show that the response time of the carbon dioxide sensor is 25S; when the gas flow rate is 250ml / min, carbon dioxide of a specific concentration (2.5% volume percentage concentration) is passed into the gas collector in the embodiment, and the results show that the response time of the carbon dioxide sensor is 27S ; When the gas flow rate was 500 ml / min, carbon dioxide of a specific concentration (2.5% volume percentage concentration) was passed into the gas collector in the comparative example, and the results showed that the response time of the carbon dioxide sensor was 28S; when the gas flow rate was 300 ml / min, carbon dioxide of a specific concentration (2.5% volume percentage concentration) was passed into the gas collector in the comparative example, and the results showed that the response time of the carbon dioxide sensor was 31S; when the gas flow rate was 250 ml / min, carbon dioxide of a specific concentration (2.5% volume percentage concentration) was passed into the gas collector in the comparative example, and the results showed that the response time of the carbon dioxide sensor was 35S.

[0037] When the gas flow rate is 300ml / min, the gas (O 2 , CH 4 ,CO,C 2 H 4 , 50% full-scale concentration of each gas) were respectively introduced into the gas collector in the embodiment. The results showed that each sensor met the response time (T 90 ) requirement, that is, each gas is detected; when the gas flow rate is 300ml / min, use gas (O 2 , CH 4 ,CO,C 2 H 4 , 50% full-scale concentration of each gas) were respectively introduced into the gas collector in the comparative embodiment. The results showed that each sensor did not meet the response time (T 90 )Require.

[0038] Referring to the specification requirements of AQ 447-1995 "Technical Requirements for Electrochemical Oxygen Sensors for Coal Mines", the underground gas collectors in the embodiment and the comparative embodiment were tested. The basic error test results show that the concentration value measurement error measured by the oxygen sensor of the gas collector in the embodiment can meet the specification requirements, while the concentration value measurement error measured by the oxygen sensor of the gas collector in the comparative embodiment cannot meet the specification requirements.

[0039] By using the gas collector in the embodiment, not only can accurate detection of multiple indicators be achieved by using the smallest possible gas collector, at least five gas parameter detection sensors can be installed on a 20mm*15mm gas collector, and gas retention in the space / air chamber below the sensor can be completely avoided; by using the gas collector in the embodiment, the detection sensitivity is high, a response can be achieved in a short time, and regulatory requirements can be met at the same time; the gas channel in the gas collector has no joints, the roughness of the inner wall of the entire gas channel is uniform, the resistance of the gas flowing therein is small and there is no swirling airflow phenomenon, and it has a small size, a simple structure, and a low manufacturing cost.

Claims

1. A downhole gas collector, comprising a plate body (1) and a gas channel arranged in the plate body (1), a plurality of gas parameter detection sensors being arranged on the gas channel, a plurality of probes of each gas parameter detection sensor being arranged circumferentially and located on the same circumference of a sensing end face, characterized in that: The gas passage comprises a plurality of holes (4) arranged at intervals, adjacent holes (4) are connected via a plurality of open chambers, the inner wall of each open chamber has a step (2), an annular groove (9) for mounting a sealing ring (26) is arranged on the step (2), a gas parameter detection sensor is mounted on the step (2), the axis of each open chamber is perpendicular to the sensing end of the gas parameter detection sensor, and the sensing end surface of the gas parameter detection sensor and the inner wall of the open chamber jointly enclose a channel for gas to enter and exit from the side; a cone-shaped baffle (3) is arranged in each open chamber, the cone-shaped baffle (3) The bottom end of the baffle (3) is connected to the bottom wall of the open cavity, and the top of the cone-shaped baffle (3) is lower than the top wall of the hole (4) and higher than the axis of the hole (4); a rib (5) is arranged transversely in the last open cavity, the bottom wall of the rib (5) is higher than the top of the cone-shaped baffle (3) in the open cavity or the bottom wall of the rib (5) is flush with the top of the cone-shaped baffle (3) in the open cavity, and along the gas flow direction, there is a gap between the rib (5) and the cone-shaped baffle (3) in the open cavity, and there is also a gap between the top wall of the rib (5) and the sensing end face of the gas parameter detection sensor.

2. The downhole gas collector according to claim 1, characterized in that: The top of the frustum-shaped baffle (3) is a hemispherical structure.

3. The downhole gas collector according to claim 2, characterized in that: The angle between the inclined wall of the frustum-shaped blocking body (3) and the axis of the frustum-shaped blocking body (3) is 42-60°.

4. The downhole gas collector according to claim 3, characterized in that: The cross section of the hole (4) is elliptical.

5. The downhole gas collector according to claim 4, characterized in that: The diameter of the hemispherical structure at the top of the frustum-shaped baffle (3) is smaller than the cross-sectional length of the hole (4).

6. The downhole gas collector according to claim 5, characterized in that: The hole (4) is directly opposite to the arc-shaped side wall of the inner wall of the open cavity.

7. The downhole gas collector according to claim 6, characterized in that: The gas channel comprises an intake channel (10), a first open cavity (11), a first hole (12), a second open cavity (13), a second hole (14), a third open cavity (15), a third hole (16), a fourth open cavity (17), a fourth hole (18), a fifth open cavity (19), and an exhaust channel (20), which are connected in sequence.

8. The downhole gas collector according to claim 7, characterized in that: The plate body (1) is manufactured using a 3D printing process and is made of engineering plastic.

9. The downhole gas collector according to claim 8, characterized in that: The bottom wall of the plate body (1) is fixed on a bracket (8), and a pressure plate (6) is arranged above the plate body (1). The pressure plate (6) is connected to the plate body (1) via a fastener (7) and presses the gas parameter detection sensor.

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