Online monitoring instrument for hydrogen sulfide gas in pipeline

Abstract

The utility model relates to the technical field of pipeline pressurized gas detection, in particular to a pipeline hydrogen sulfide gas online monitor which comprises a gas mixing cabin, the gas mixing cabin is respectively connected with a first pipeline, a second pipeline and a third pipeline, and the first pipeline, the second pipeline and the third pipeline are respectively provided with a control valve. The gas mixing cabin is connected with pipeline gas through a first pipeline, connected with oxygen-containing gas through a second pipeline, connected with the gas decompression cabin through a third pipeline and further connected with a fourth pipeline, the other end of the fourth pipeline is connected with the vacuumizing assembly, and the fourth pipeline is connected with a check valve b; the gas decompression chamber is connected with a circulating pipeline, and an H2S sensor is arranged on the circulating pipeline. The device is optimized in structure, small in size, safe, reliable, energy-saving and environment-friendly, and can remotely monitor the hydrogen sulfide gas under pressure in the pipeline in real time.

Description

Technical Field

[0001] The utility model relates to the technical field of pipeline pressurized gas detection, in particular to an online pipeline hydrogen sulfide gas monitor. Background Art

[0002] Oil and gas wells in oil fields contain H 2 S is a toxic gas. If it leaks, it will not only affect the production of the enterprise but also cause harm to personal safety. In order to ensure the safety of production and personnel, enterprises need to regularly test the gas in the oil and gas well pipelines.

[0003] At present, the commonly used method is for workers to wear protective clothing and carry special containers to the wellheads of various oil and gas wells to collect samples for testing. Due to factors such as frequent sampling, long distances and complex environments, manual sampling is not only inefficient, time-consuming and costly, but also poses the risk of gas leakage and endangering the safety of personnel.

[0004] In the prior art, the above-mentioned problem can be solved by using a remote online method to detect the gas in the oil wellhead pipeline. For example, the Chinese patent with the authorization announcement number CN117948075B developed by the applicant discloses an integrated fluid control device for multi-scenario applications, which can realize the remote automatic collection of oil well pipeline gas. However, the oil well pipeline gas collected remotely and automatically has a high pressure, and the H 2 The S sensor is only suitable for working in a normal pressure environment. Gases with higher pressure cannot be directly regulated by H 2 S sensor for detection.

[0005] In response to the above problems, the applicant has developed a Chinese patent with the authorization announcement number CN221628139U, which discloses an intelligent crude oil wellhead pipeline hydrogen sulfide online detector. The detection unit of the detector can reduce the pressure of the pipeline gas, thereby detecting H2S in the reduced-pressure pipeline gas. 2 S detection solves H 2 The S sensor cannot detect the high-pressure pipeline gas, so as to perform real-time remote monitoring of hydrogen sulfide in the pipeline pressurized gas.

[0006] The applicant has made further improvements and optimizations to the above detector, mainly focusing on the following shortcomings: First, in the detector, the pipeline gas containing hydrogen sulfide is directly injected into the functional cabin, and the functional cabin is 2 If the concentration of hydrogen sulfide in the functional compartment is too high, when H 2When the S sensor a is turned on and off, electric sparks may occur due to the electric start and stop, and there is a risk of igniting an explosion of high-concentration hydrogen sulfide. Although the probability of such an accident is very low, prevention is still necessary; second, the overall size of the detector is large, the space occupied and the manufacturing cost are large; third, there is no restriction on the pipeline gas entering the detector, and there is a certain risk of excessive pressure. Utility Model Content

[0007] The utility model is an improvement on the prior art, and provides an online monitoring instrument for pipeline hydrogen sulfide gas.

[0008] In order to solve the above technical problems, the utility model provides the following technical solutions:

[0009] A pipeline hydrogen sulfide gas online monitor comprises a gas mixing chamber, the gas mixing chamber is connected to a first pipeline, a second pipeline and a third pipeline respectively, the first pipeline, the second pipeline and the third pipeline are respectively provided with control valves, the gas mixing chamber is connected to the pipeline gas through the first pipeline, the gas mixing chamber is connected to the oxygen-containing gas through the second pipeline, the gas mixing chamber is connected to the gas decompression chamber through the third pipeline, the gas mixing chamber is also connected to a fourth pipeline, the other end of the fourth pipeline is connected to a vacuum pumping component, the fourth pipeline is connected to a check valve b, the gas decompression chamber is connected to a circulation pipeline, the circulation pipeline is provided with H 2 S sensor, the gas mixing cabin is provided with a pressure sensor a, and the gas decompression cabin is provided with a pressure sensor b.

[0010] Since pipeline gas is extracted from oil wells and does not contain oxygen, most electrochemical sensors in the prior art require oxygen to participate in the reaction. 2 The S sensor also requires oxygen during detection. Therefore, more than 3% oxygen needs to be added when detecting hydrogen sulfide. In the above structure, the gas mixing chamber mixes the pipeline gas entering it with oxygen-containing gas (preferably air) to meet the H2S detection requirement. 2 S sensor detection conditions;

[0011] The control valve on the third pipeline controls the mixed gas entering the gas decompression chamber. When the gas decompression chamber reaches normal pressure, the control valve on the third pipeline is closed, so that the gas in the gas decompression chamber meets H 2 S sensor detection conditions;

[0012] In addition, the vacuuming component can evacuate and reduce the negative pressure of the gas mixing chamber and the gas decompression chamber. The purpose of vacuuming is to remove the residual gas in the gas mixing chamber and the gas decompression chamber to ensure the accuracy of real-time gas detection data; reducing the negative pressure has two purposes: first, reducing the negative pressure in the gas mixing chamber: the pipeline gas does not contain oxygen, H 2The S sensor cannot detect normally. The oxygen content in the air is about 21%. It can be solved by injecting external air into the gas mixing chamber. Since the external air is at normal pressure, it is necessary to reduce the gas mixing chamber to negative pressure in advance to allow air to enter. Second, the gas decompression chamber reduces the negative pressure: H 2 The S sensor is not pressure-resistant and needs to work in a normal pressure environment. After the gas decompression chamber is reduced to negative pressure, the pressure of the gas to be tested sent into the gas mixing chamber will drop after entering. As the gas continues to enter, the pressure gradually rises to normal pressure, making it easier to detect.

[0013] The output end of the vacuum pumping component is connected to a fifth pipeline, and a check valve c is connected to the fifth pipeline.

[0014] The output end of the fifth pipeline is connected to the pipeline gas. The above structure can return the extracted gas to the pipeline gas to avoid polluting the external air.

[0015] The vacuum pumping assembly comprises a piston chamber, which is respectively connected to the fourth pipeline and the fifth pipeline. A piston is slidably arranged in the piston chamber, and the piston is connected to a push-pull power mechanism.

[0016] The push-pull power mechanism comprises a push-pull electromagnet, which is arranged outside the piston cavity. A push-pull rod of the push-pull electromagnet passes through the piston cavity and is fixedly connected to the piston.

[0017] The vacuum assembly includes a vacuum pump.

[0018] The control valve on the first pipeline is a solenoid valve a, and the first pipeline is also provided with a check valve a. The solenoid valve a controls the pipeline gas entering the gas mixing chamber, and the check valve a controls the one-way flow of the gas and prevents backflow under special circumstances.

[0019] The first pipeline is provided with a flow limiting valve, which not only controls the size of the gas flow, but can also be preset to prevent the gas flow from being too large, thereby preventing the gas pressure entering the mixing chamber from exceeding a specified value.

[0020] The control valve on the second pipeline is a solenoid valve b, which controls the external air entering the gas mixing cabin.

[0021] The control valve on the third pipeline is a solenoid valve c, and the solenoid valve c controls the mixed gas entering the gas decompression chamber.

[0022] The circulation pipeline is provided with an air pump, a check valve d and a solenoid valve d. The solenoid valve d and the check valve d prevent H from being released during the process of exhaust gas cleaning, negative pressure reduction and gas entering the gas decompression chamber. 2 S sensor undervoltage or overvoltage.

[0023] The beneficial effects achieved by the utility model are:

[0024] In the present utility model, H 2 The S sensor and the gas mixing chamber are set up in two modules to avoid H 2 The S sensor contacts the hydrogen sulfide gas with a high concentration, thereby avoiding gas explosion caused by electric sparks. Compared with the prior art, the utility model is safer.

[0025] In the utility model, the gas after detection is directly sent back to the pipeline gas, and there is no need to set up a gas recovery tank, so that the utility model has an optimized structure and a small volume.

[0026] The first pipeline of the utility model is provided with a flow limiting valve, so as to prevent the pressure of the gas entering the gas mixing cabin from exceeding a specified value.

[0027] The application of the utility model in enterprise production will improve efficiency, ensure safe operation, avoid harm to the human body caused by leakage of toxic gases, and reduce the cost and risk of manual detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0029] Figure 1 It is a structural schematic diagram of the first embodiment of the utility model;

[0030] Figure 2 It is a structural schematic diagram of the vacuum pumping assembly in the first embodiment of the utility model (exhaust state);

[0031] Figure 3 It is a structural schematic diagram of the vacuum assembly in the first embodiment of the utility model (inhalation state);

[0032] Figure 4 It is a structural schematic diagram of the second embodiment of the present utility model.

[0033] In the figure: 1, solenoid valve a; 2, first pipeline; 3, check valve a; 4, flow limiting valve; 5, gas mixing chamber; 6, solenoid valve c; 7, third pipeline; 8, solenoid valve b; 9, gas decompression chamber; 10, circulation pipeline; 11, solenoid valve d; 12, H 2 S sensor; 13. air pump; 14. check valve d; 15. pressure sensor b; 16. pressure sensor a; 17. check valve b; 18. fourth pipeline; 19. pipeline gas; 20. fifth pipeline; 21. check valve c; 22. piston chamber; 23. push-pull electromagnet; 24. piston; 25. push-pull rod; 26. second pipeline; 27. vacuum pump. DETAILED DESCRIPTION

[0034] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0035] Embodiment 1:

[0036] like Figure 1 , Figure 2 , Figure 3 As shown, an online monitor for pipeline hydrogen sulfide gas includes a gas mixing chamber 5, the gas mixing chamber 5 is connected to a first pipeline 2, a second pipeline 26 and a third pipeline 7 respectively, the first pipeline 2, the second pipeline 26 and the third pipeline 7 are respectively provided with control valves, the gas mixing chamber 5 is connected to the pipeline gas 19 through the first pipeline 2, the gas mixing chamber 5 is connected to the oxygen-containing gas through the second pipeline 26, the gas mixing chamber 5 is connected to the gas decompression chamber 9 through the third pipeline 7, the gas mixing chamber 5 is also connected to a fourth pipeline 18, the other end of the fourth pipeline 18 is connected to a vacuum pumping component, the fourth pipeline 18 is connected to a check valve b17, the gas decompression chamber 9 is connected to a circulation pipeline 10, and the circulation pipeline 10 is provided with a H 2 S sensor 12, the gas mixing chamber 5 is provided with a pressure sensor a16, and the gas decompression chamber 9 is provided with a pressure sensor b15.

[0037] Since the pipeline gas 19 is extracted from the oil well and does not contain oxygen, most electrochemical sensors in the prior art require oxygen to participate in the reaction. 2 The S sensor 12 also requires oxygen to participate in the detection. Therefore, more than 3% of oxygen needs to be added when performing hydrogen sulfide detection. In the above structure, the gas mixing chamber 5 mixes the pipeline gas 19 introduced into it with the oxygen-containing gas (preferably air) to meet the H2S detection requirement. 2 S sensor 12 detection conditions;

[0038] The control valve on the third pipeline 7 controls the mixed gas entering the gas decompression chamber 9. When the interior of the gas decompression chamber 9 reaches normal pressure, the control valve on the third pipeline 7 is closed, so that the gas in the gas decompression chamber 9 meets H 2 S sensor 12 detection conditions;

[0039] In addition, the vacuuming component can evacuate and reduce the negative pressure of the gas mixing cabin 5 and the gas decompression cabin 9. The purpose of vacuuming is to remove the residual gas in the gas mixing cabin 5 and the gas decompression cabin 9 to ensure the accuracy of real-time gas detection data; reducing the negative pressure has two purposes: first, reducing the negative pressure of the gas mixing cabin 5: the pipeline gas 19 does not contain oxygen, H 2The S sensor 12 cannot detect normally. The oxygen content in the air is about 21%. It can be solved by injecting external air into the gas mixing cabin 5. Since the external air is at normal pressure, it is necessary to reduce the gas mixing cabin 5 to negative pressure in advance to allow air to enter. Second, the gas decompression cabin 9 reduces the negative pressure: H 2 The S sensor 12 is not pressure-resistant and needs to work in a normal pressure environment. After the gas decompression chamber 9 is reduced to a negative pressure, the pressure of the detected gas sent into the gas mixing chamber 5 will decrease after entering. As the gas continues to enter, the pressure gradually rises to normal pressure, thereby facilitating detection.

[0040] The output end of the vacuum pumping assembly is connected to the fifth pipeline 20, and a check valve c21 is connected to the fifth pipeline 20. The output end of the fifth pipeline 20 is connected to the pipeline gas 19. The above structure can return the extracted gas to the pipeline gas 19 to avoid polluting the external air.

[0041] The vacuum pumping assembly includes a piston chamber 22, which is connected to the fourth pipe 18 and the fifth pipe 20 respectively. A piston 24 is slidably arranged in the piston chamber 22, and the piston 24 is connected to a push-pull power mechanism.

[0042] The push-pull power mechanism includes a push-pull electromagnet 23, which is arranged outside the piston cavity 22. The push-pull rod 25 of the push-pull electromagnet 23 passes through the piston cavity 22 and is fixedly connected to the piston 24. The push-pull electromagnet 23 uses a push-pull electromagnet structure commonly used in the prior art, which adjusts the strength of the magnetism by using different electromagnetic coils and power supplies, and turns it into a push-pull action to achieve a linear reciprocating motion of the push-pull rod 25. The above structure is small in size and convenient for installation and use.

[0043] The push-pull power mechanism can also adopt other reciprocating linear power structures such as electric cylinders.

[0044] The control valve on the first pipeline 2 is a solenoid valve a1, and a check valve a3 is also provided on the first pipeline 2. The solenoid valve a1 controls the pipeline gas 19 entering the gas mixing chamber 5, and the check valve a3 controls the one-way flow of the gas and prevents backflow under special circumstances.

[0045] The first pipeline 2 is provided with a flow limiting valve 4, which not only controls the size of the gas flow, but can also be preset to prevent the gas flow from being too large, thereby preventing the gas pressure entering the mixing chamber from exceeding a specified value.

[0046] The control valve on the second pipeline 26 is a solenoid valve b8 , which controls the external air entering the gas mixing chamber 5 .

[0047] The control valve on the third pipeline 7 is a solenoid valve c6 , which controls the mixed gas entering the gas decompression chamber 9 .

[0048] The circulation pipeline 10 is provided with a check valve d14 and a solenoid valve d11, which prevent H from flowing into the exhaust gas during the process of cleaning the exhaust gas, reducing the negative pressure, and the gas entering the gas decompression chamber 9. 2 S sensor 12 is undervoltage or overvoltage.

[0049] In order to ensure that the detection data is accurate and real-time, and at the same time make each structural unit function normally, before collecting and detecting hydrogen sulfide gas, it is necessary to clear the residual waste gas in the gas mixing chamber 5 and the gas decompression chamber 9. Therefore, the work flow is divided into two parts:

[0050] (I) Exhaust gas cleaning and negative pressure reduction: According to the setting of the intelligent control program, the control circuit first opens the solenoid valve c6, and turns the push-pull electromagnet 23 on and off for many times. The piston 24 reciprocates under the drive of the push-pull electromagnet 23, that is, inhaling and exhausting air. Figure 2 , Figure 3 As shown, when the piston 24 inhales, the check valve c21 is closed and the check valve b17 is opened, and the gas in the gas decompression chamber 9 and the gas mixing chamber 5 is sucked into the piston chamber 22 by the piston 24 through the check valve b17. When the piston 24 exhausts, the check valve b17 is closed and the check valve c21 is opened, and the gas in the piston chamber 22 is pushed into the pipeline gas 19 through the check valve c21. The piston 24 performs repeated movements driven by the push-pull electromagnet 23. When the values ​​of the pressure sensors a16 and b15 in the gas decompression chamber 9 and the gas mixing chamber 5 drop to a specified negative pressure, the push-pull electromagnet 23 stops working, and the electromagnetic valve c6 is closed at the same time.

[0051] (II) Gas collection, mixing and detection: To make the pipeline gas 19 contain oxygen, it is convenient for H 2S sensor 12 detects that air needs to be mixed in. Since the pressure of pipeline gas 19 is greater than that of air, it is necessary to introduce external air into gas mixing cabin 5 in advance. Therefore, the control circuit first opens electromagnetic valve b8, and external air enters gas mixing cabin 5 in negative pressure state through electromagnetic valve b8. When the value of pressure sensor a16 rises to normal pressure, the control circuit closes electromagnetic valve b8. Then electromagnetic valve a1 is opened, and pressurized pipeline gas 19 enters gas mixing cabin 5 through electromagnetic valve a1, check valve a3 and flow limiting valve 4. Flow limiting valve 4 has been pre-set according to the air pressure of gas pipeline pressure gauge, so the airflow entering gas mixing cabin 5 is small. Since the diameter and volume of gas mixing cabin 5 are large, the pressure of entering gas is gradually rising. When the air pressure in gas mixing cabin 5 reaches the specified value, electromagnetic valve a1 is closed, and the air in gas mixing cabin 5 is also mixed with pipeline gas 19. At the same time, the control circuit opens the electromagnetic valve c6, and the gas in the gas mixing chamber 5 enters the gas decompression chamber 9 through the electromagnetic valve c6. The structural principle of the gas decompression chamber 9 is the same as that of the gas mixing chamber 5 and is also in a negative pressure state. After the gas enters, the pressure gradually rises. When the electromagnetic valve c6 reaches the normal pressure, the control circuit opens the electromagnetic valve d11, and turns on the air pump 13 and H at the same time. 2 S sensor 12, air pump 13 extracts gas from gas decompression chamber 9 through check valve d14 and transports it to H 2 S sensor 12, H 2 The S sensor 12 continuously detects hydrogen sulfide while the gas is circulating, and uploads the data through the remote transmission circuit; after the detection process is completed, the control circuit controls the air pump 13, H 2 The S sensor 12 and the solenoid valve d11 are closed successively, and the solenoid valve c6 is opened at the same time, and the push-pull electromagnet 23 is turned on and off for many times. The piston 24 is driven by the push-pull electromagnet 23 to inhale or exhaust, and the waste gas in the gas mixing chamber 5 and the gas decompression chamber 9 is injected back into the pipeline gas 19; when the pressure sensors a16 and b15 of the two chambers are respectively reduced to the specified pressure values, the control circuit will close the push-pull electromagnet 23 and the solenoid valve c6 successively, and the hydrogen sulfide gas detection work is completed.

[0052] The testing process performs two similar exhaust gas cleanings before and after the hydrogen sulfide test, with the goal of ensuring that the structural unit is working properly and that there is no residual gas present to enable accurate hydrogen sulfide testing.

[0053] Compared with the prior art with authorization announcement number CN221628139U, the utility model is safer and more reliable, specifically:

[0054] First, inject air into the gas mixing cabin 5, and then inject the pipeline gas 19 into the gas mixing cabin 5. Since the volume of the gas mixing cabin 5 has been determined and the negative pressure after the cabin is evacuated has been set, the injected external air is also controlled within a certain quantity range. The pipeline gas 19 containing hydrogen sulfide entering the gas mixing cabin 5 at a later stage is gradually increasing and is also continuously diluted. When the air pressure in the cabin reaches the set pressure, the gas stops entering, and at the same time, the mixing ratio of hydrogen sulfide gas and air is controlled within a safe range. The utility model injects air first and then injects hydrogen sulfide gas. Compared with the method of injecting hydrogen sulfide gas first and then air, the utility model can avoid the possibility of explosion caused by excessively high concentration of hydrogen sulfide mixed with air and encountering open flames;

[0055] H 2 The S sensor 12 and the gas mixing chamber 5 are arranged in two modules to avoid H 2 The S sensor 12 is exposed to high concentration of hydrogen sulfide gas to avoid gas explosion caused by electric sparks.

[0056] In addition, the vacuum assembly plays three different roles at different stages of the process: first, vacuuming and reducing negative pressure; second, reducing the pressure of the gas mixing chamber 5; and third, injecting the detected waste gas back into the pipeline gas 19, thereby optimizing the structural links, reducing the failure rate, and reducing costs and increasing efficiency. The vacuum assembly adopts the structure of the piston 24 and the push-pull electromagnet 23. The piston 24 is in direct contact with the gas to prevent the gas from contacting the charged structure, thereby reducing safety risks.

[0057] Embodiment 2:

[0058] like Figure 4 As shown, the structure of the second embodiment is basically the same as that of the first embodiment, except that, in this embodiment, the vacuum pump assembly adopts a vacuum pump 27, the input end of the vacuum pump 27 is connected to the fourth pipeline 18, and the output end is connected to the fifth pipeline 20, and the vacuum pump 27 is used to perform the vacuum operation.

Claims

1. A pipeline hydrogen sulfide gas online monitor, characterized in that: The invention comprises a gas mixing chamber (5), the gas mixing chamber (5) being connected to a first pipeline (2), a second pipeline (26) and a third pipeline (7), respectively, control valves being arranged on the first pipeline (2), the second pipeline (26) and the third pipeline (7), respectively, the gas mixing chamber (5) being connected to pipeline gas (19) via the first pipeline (2), the gas mixing chamber (5) being connected to oxygen-containing gas via the second pipeline (26), the gas mixing chamber (5) being connected to a gas decompression chamber (9) via the third pipeline (7), the gas mixing chamber (5) being further connected to a fourth pipeline (18), the other end of the fourth pipeline (18) being connected to a vacuum pumping assembly, the fourth pipeline (18) being connected to a check valve b (17), the gas decompression chamber (9) being connected to a circulation pipeline (10), the circulation pipeline (10) being provided with an H2S sensor (12), the gas mixing chamber (5) being provided with a pressure sensor a (16), and the gas decompression chamber (9) being provided with a pressure sensor b (15).

2. The pipeline hydrogen sulfide gas online monitor according to claim 1, characterized in that: The output end of the vacuum pumping component is connected to a fifth pipeline (20), and a check valve c (21) is connected to the fifth pipeline (20).

3. The pipeline hydrogen sulfide gas online monitor according to claim 2, characterized in that: The output end of the fifth pipeline (20) is connected to the pipeline gas (19).

4. The pipeline hydrogen sulfide gas online monitor according to claim 2 or 3, characterized in that: The vacuum pumping assembly comprises a piston chamber (22), the piston chamber (22) being connected to the fourth pipe (18) and the fifth pipe (20) respectively, a piston (24) being slidably disposed in the piston chamber (22), and the piston (24) being connected to a push-pull power mechanism.

5. The pipeline hydrogen sulfide gas online monitor according to claim 4, characterized in that: The push-pull power mechanism comprises a push-pull electromagnet (23), which is arranged outside the piston cavity (22). A push-pull rod (25) of the push-pull electromagnet (23) passes through the piston cavity (22) and is fixedly connected to the piston (24).

6. The pipeline hydrogen sulfide gas online monitor according to claim 2 or 3, characterized in that: The vacuum extraction component comprises a vacuum pump (27).

7. The pipeline hydrogen sulfide gas online monitor according to claim 1, characterized in that: The control valve on the first pipeline (2) is a solenoid valve a (1), and a check valve a (3) is also provided on the first pipeline (2).

8. The pipeline hydrogen sulfide gas online monitor according to claim 1 or 7, characterized in that: A flow limiting valve (4) is provided on the first pipeline (2).

9. The pipeline hydrogen sulfide gas online monitor according to claim 1, characterized in that: The control valve on the second pipeline (26) is a solenoid valve b (8); the control valve on the third pipeline (7) is a solenoid valve c (6).

10. The pipeline hydrogen sulfide gas online monitor according to claim 1, characterized in that: The circulation pipeline (10) is provided with an air pump (13), a check valve d (14) and a solenoid valve d (11).

Images