Online detection system for tetrahydrothiophene and hydrogen sulfide in natural gas

Abstract

The utility model relates to the technical field of natural gas detection, in particular to an online detection system for tetrahydrothiophene and hydrogen sulfide in natural gas. An inlet of the three-way electromagnetic valve is communicated with a natural gas source outlet; an inlet of the balance pipeline is communicated with a first outlet of the three-way electromagnetic valve; an inlet of the detection pipeline is communicated with a second outlet of the three-way electromagnetic valve, and the detection pipeline is sequentially communicated with a tetrahydrothiophene sensor and a hydrogen sulfide sensor in the flowing direction of the natural gas; the purging pipeline is used for purging residual natural gas in the detection pipeline before and after detection; the waste gas filtering device is used for filtering tetrahydrothiophene and hydrogen sulfide in the natural gas, and an outlet of the balance pipeline and an outlet of the hydrogen sulfide sensor are respectively communicated with an inlet of the waste gas filtering device. The device realizes simultaneous detection of the content of tetrahydrothiophene and hydrogen sulfide and intermittent measurement, avoids sensor poisoning, and prolongs the service life of the system.

Description

Technical Field

[0001] This utility model relates to the field of natural gas detection technology, and in particular to an online detection system for tetrahydrothiophene and hydrogen sulfide in natural gas. Background Art

[0002] Natural gas, as a clean energy source, offers convenience and relative safety, greatly improving the home environment and enhancing the quality of life. However, natural gas is colorless and odorless, making leaks difficult to detect and posing a safety hazard. Therefore, odorants (usually tetrahydrothiophene or other sulfides) are mixed into natural gas during transportation to give it a distinctive, unpleasant warning odor, making leaks detectable.

[0003] In existing technologies, handheld, diffusion, and pipeline methods are commonly used to detect the content of tetrahydrothiophene and hydrogen sulfide in natural gas. However, existing detection methods have the following technical problems:

[0004] 1. The same testing instrument or system can only detect the concentration of a certain content.

[0005] 2. Tetrahydrothiophene and hydrogen sulfide sensors are prone to methane poisoning if they are kept in the pipeline under test for a long time. Utility Model Content

[0006] To address at least one of the aforementioned technical problems, this invention proposes an online detection system for tetrahydrothiophene and hydrogen sulfide in natural gas, which solves the problems of not being able to simultaneously detect the content of tetrahydrothiophene and hydrogen sulfide, not being able to perform intermittent measurements, and avoiding sensor poisoning.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] An online detection system for tetrahydrothiophene and hydrogen sulfide in natural gas includes:

[0009] Natural gas source, used to provide the natural gas to be tested;

[0010] A three-way solenoid valve, the three-way solenoid valve having an inlet and a first outlet and a second outlet respectively connected to the inlet, the inlet being connected to the natural gas source outlet;

[0011] A balancing pipeline is used to balance the pressure and flow of the natural gas pipeline, and the inlet of the balancing pipeline is connected to the first outlet of the three-way solenoid valve.

[0012] A detection pipeline is used to detect the content of tetrahydrothiophene and hydrogen sulfide in natural gas. The inlet of the detection pipeline is connected to the second outlet of the three-way solenoid valve. A tetrahydrothiophene sensor and a hydrogen sulfide sensor are sequentially connected along the natural gas flow direction on the detection pipeline. The tetrahydrothiophene sensor is used to detect the tetrahydrothiophene content of the natural gas in the detection pipeline, and the hydrogen sulfide sensor is used to detect the hydrogen sulfide content of the natural gas in the detection pipeline.

[0013] A purging pipeline is used to purge residual natural gas from the detection pipeline before and after detection.

[0014] An exhaust gas filtration device is used to filter tetrahydrothiophene and hydrogen sulfide in natural gas. The outlet of the balance pipeline and the outlet of the hydrogen sulfide sensor are respectively connected to the inlet of the exhaust gas filtration device.

[0015] Preferably, the purging line includes an air pump and a second solenoid valve connected to the outlet of the air pump, the outlet of the second solenoid valve being connected to the inlet of the tetrahydrothiophene sensor.

[0016] Preferably, the online detection system further includes a delivery pipeline connecting the outlet of the natural gas source and the inlet of the three-way solenoid valve, wherein the delivery pipeline is sequentially connected to a pressure reducing valve, a flow regulating valve and a first solenoid valve along the natural gas flow direction.

[0017] Preferably, the online detection system further includes a control system, which is connected to the first solenoid valve, the second solenoid valve, the three-way solenoid valve, the air pump, the tetrahydrothiophene sensor, and the hydrogen sulfide sensor.

[0018] Preferably, the control system includes a main control circuit board, an analog signal transmission module connected to the main control circuit board, and a communication module connected to the main control circuit board.

[0019] Preferably, the online detection system further includes a display screen connected to the control system for displaying the detection results of the tetrahydrothiophene sensor and the hydrogen sulfide sensor.

[0020] Preferably, the online detection system further includes an alarm device connected to the control system, which is used to issue an alarm signal when the detection value of the tetrahydrothiophene sensor and / or hydrogen sulfide sensor exceeds a set threshold.

[0021] Preferably, the waste gas filtration device is an activated carbon adsorption chamber.

[0022] Preferably, the online detection system further includes an explosion-proof housing.

[0023] Preferably, the air pump is one of a miniature diaphragm air pump, a small vortex air pump, or an electromagnetic air pump; the three-way solenoid valve is a diversion type three-way solenoid valve; and the natural gas source is a natural gas pipeline.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. In this embodiment, a balancing pipeline is set up. Before detection, natural gas enters the balancing pipeline through the normally open channel of the three-way solenoid valve to form a natural gas passage, thereby solving the problem of unbalanced gas pressure and flow caused by the closure of the natural gas passage. This avoids the impact of excessively high or low natural gas pressure and flow on the detection results of the tetrahydrothiophene sensor and the hydrogen sulfide sensor.

[0026] 2. This invention detects the content of tetrahydrothiophene and hydrogen sulfide in natural gas by setting up a detection pipeline, avoiding interference from hydrogen sulfide mixed in the natural gas on the tetrahydrothiophene detection results. Simultaneously, by setting up a purging pipeline, the detection pipeline can be pre-purged before detection to remove any small amounts of natural gas that may be present in the pipeline, improving the accuracy of subsequent tetrahydrothiophene and hydrogen sulfide detection results; after detection, the detection pipeline is purged again to prevent residual natural gas in the detection pipeline from poisoning the tetrahydrothiophene and hydrogen sulfide sensors. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of an online detection system for tetrahydrothiophene and hydrogen sulfide in natural gas.

[0028] In the diagram: 1. Natural gas source; 2. Pressure reducing valve; 3. Flow regulating valve; 4. First solenoid valve; 5. Three-way solenoid valve; 6. Second solenoid valve; 7. Gas pump; 8. Tetrahydrothiophene sensor; 9. Hydrogen sulfide sensor; 10. Sensor circuit board; 11. Main control circuit board; 12. Display screen; 13. Analog signal transmission module; 14. Communication module; 15. Exhaust gas filtration device; 16. Detection pipeline; 17. Balancing pipeline; 18. Gas chamber; 19. Explosion-proof enclosure. DETAILED DESCRIPTION

[0029] To enable those skilled in the art to better understand the technical solutions in this utility model, the technical solutions in the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments in this utility model, and not all of the embodiments in this utility model.

[0030] Please refer to Figure 1 As shown, an online detection system for tetrahydrothiophene and hydrogen sulfide in natural gas includes:

[0031] Natural gas source 1, used to provide the natural gas to be tested;

[0032] Three-way solenoid valve 5, the three-way solenoid valve 5 has an inlet and a first outlet and a second outlet respectively connected to the inlet, the inlet being connected to the outlet of natural gas source 1;

[0033] The balancing pipeline 17 is used to balance the pressure and flow of the natural gas pipeline. The inlet of the balancing pipeline 17 is connected to the first outlet of the three-way solenoid valve 5.

[0034] The detection pipeline 16 is used to detect the content of tetrahydrothiophene and hydrogen sulfide in natural gas. The inlet of the detection pipeline 16 is connected to the second outlet of the three-way solenoid valve 5. A tetrahydrothiophene sensor 8 and a hydrogen sulfide sensor 9 are connected sequentially along the natural gas flow direction on the detection pipeline 16. The tetrahydrothiophene sensor 8 is used to detect the tetrahydrothiophene content of the natural gas in the detection pipeline 16, and the hydrogen sulfide sensor 9 is used to detect the hydrogen sulfide content of the natural gas in the detection pipeline 16.

[0035] The purging pipeline is used to purge residual natural gas in the detection pipeline 16 before and after detection.

[0036] The exhaust gas filter 15 is used to filter tetrahydrothiophene and hydrogen sulfide in natural gas. The outlet of the balance pipeline 17 and the outlet of the hydrogen sulfide sensor 9 are respectively connected to the inlet of the exhaust gas filter 15.

[0037] In this embodiment, a balancing pipeline 17 is provided. Before detection, natural gas enters the balancing pipeline 17 through the normally open channel of the three-way solenoid valve 5 to form a natural gas passage, thereby solving the problem of unbalanced gas pressure and flow caused by the closure of the natural gas passage. This avoids the impact of excessively high or low natural gas pressure and flow on the detection results of the tetrahydrothiophene sensor 8 and the hydrogen sulfide sensor 9.

[0038] Specifically, excessively high pressure may damage the pipeline and affect the detection accuracy of the sensors, while excessively low pressure may prevent natural gas from passing through the sensors at a stable flow rate or cause local gas stagnation or flow cessation, thus making the sensor results unable to accurately reflect the actual tetrahydrothiophene and hydrogen sulfide content in the natural gas. Appropriate flow rates ensure sufficient contact time between the tetrahydrothiophene sensor 8 and the hydrogen sulfide sensor 9 and the natural gas, guaranteeing detection sensitivity.

[0039] By setting up detection pipeline 16 to detect the content of tetrahydrothiophene and hydrogen sulfide in natural gas, the interference of some hydrogen sulfide mixed in the natural gas on the tetrahydrothiophene detection results is avoided. At the same time, by setting up a purging pipeline, detection pipeline 16 can be pre-purged before detection to remove any small amount of natural gas that may be present in detection pipeline 16, thereby improving the accuracy of subsequent tetrahydrothiophene and hydrogen sulfide detection results; after detection, detection pipeline 16 is purged again to prevent residual natural gas in detection pipeline 16 from poisoning the tetrahydrothiophene sensor 8 and hydrogen sulfide sensor 9.

[0040] Specifically, the tetrahydrothiophene sensor 8 and the hydrogen sulfide sensor 9 are exposed to natural gas for extended periods. The presence of substances such as tetrahydrothiophene and hydrogen sulfide in natural gas causes the sensitive elements of the sensors to become oversaturated, reducing the detection accuracy and lifespan of the sensors.

[0041] Furthermore, the zero point of the sensor may drift when exposed to a natural gas environment for an extended period. This is because the sensor may be affected by adsorption and interference from various components in the natural gas. Even in the absence of the target gas component, the sensor may output a non-zero signal, altering the sensor's zero-point baseline.

[0042] The purging pipeline in this embodiment includes an air pump 7 and a second solenoid valve 6 connected to the outlet of the air pump 7. The outlet of the second solenoid valve 6 is connected to the inlet of the tetrahydrothiophene sensor 8.

[0043] Specifically, by controlling the second solenoid valve 6 and the air pump 7, the detection pipeline 16 is purged before and after the detection to remove residual natural gas from the detection pipeline 16. The air pump 7 can be any one of a miniature diaphragm air pump, a small vortex air pump, or an electromagnetic air pump.

[0044] It should be noted that in this embodiment, the three-way solenoid valve 5 is a diversion type three-way solenoid valve, and the natural gas source 1 is a natural gas pipeline.

[0045] In order to ensure that the natural gas in the pipeline has a stable pressure and flow rate, a delivery pipeline is installed between the outlet of the natural gas source 1 and the inlet of the three-way solenoid valve 5 in this embodiment.

[0046] Specifically, the pipeline is sequentially connected to a pressure reducing valve 2, a flow regulating valve 3, and a first solenoid valve 4 along the natural gas flow direction. It should be noted that during installation, the pressure reducing valve 2 and the flow regulating valve 3 are used to adjust the natural gas pressure and flow rate to a suitable range, while the first solenoid valve 4 facilitates the control of the natural gas flow. This creates favorable, stable, and controllable gas intake conditions for the detection system.

[0047] Please refer to Figure 1As shown, a control system is also provided in this embodiment to facilitate automatic control of the detection system. The control system is connected to the first solenoid valve 4, the second solenoid valve 6, the three-way solenoid valve 5, the air pump 7, the tetrahydrothiophene sensor 8, and the hydrogen sulfide sensor 9.

[0048] In this embodiment, the control system includes a main control circuit board 11, an analog signal transmission module 13 connected to the main control circuit board 11, and a communication module 14 connected to the main control circuit board 11. The tetrahydrothiophene sensor 8 and the hydrogen sulfide sensor 9 are connected to the main control circuit board 11 via a sensor circuit board 10.

[0049] It should be noted that the analog signal transmission module 13 in this embodiment uses a (4-20)mA module, which converts the signals output by the tetrahydrothiophene sensor 8 and the hydrogen sulfide sensor 9 into a standard 4-20mA current signal. This current signal has strong anti-interference capability because it is less affected by line resistance and electromagnetic interference during transmission, and can transmit the detected information more stably.

[0050] The communication module 14 uses a wireless 4G module. Its advantages include being unrestricted by distance, enabling real-time transmission of monitoring system data from different areas (whether urban or remote mountainous) to the remote monitoring center within the 4G network coverage area, and flexible installation location. Simultaneously, the high-speed characteristics of the 4G network ensure timely data updates, achieving real-time monitoring and rapid response, and also support remote control functions; it is easy to connect to IoT platforms, allowing it to work collaboratively with other wireless devices, improving system scalability and compatibility; furthermore, it significantly reduces wiring costs and maintenance difficulty, minimizing the risk of cable-related failures and maintenance workload, providing strong support for the stable and efficient operation of the natural gas monitoring system.

[0051] To facilitate real-time viewing of test data by staff, the online testing system in this embodiment also includes a display screen 12. The display screen 12 is connected to the control system, allowing staff to view the test results of the tetrahydrothiophene sensor 8 and the hydrogen sulfide sensor 9 in real time.

[0052] To alert staff that the concentration of tetrahydrothiophene and / or hydrogen sulfide exceeds the limit, the online detection system in this embodiment is also equipped with an alarm device.

[0053] Specifically, the alarm device is connected to the control system, and the staff can pre-set threshold values ​​for the detection values ​​of the tetrahydrothiophene sensor 8 and the hydrogen sulfide sensor 9. When the detection value of the tetrahydrothiophene sensor 8 and / or the hydrogen sulfide sensor 9 exceeds the set threshold, an alarm signal can be issued in a timely manner to remind the operator to take appropriate measures, such as investigating the cause of the abnormality or carrying out emergency handling.

[0054] The alarm devices described above can be configured with one or more combined alarm modes to ensure that warning signals can be sent to relevant personnel in a timely and effective manner.

[0055] Specifically, common alarm methods include audible alarms, such as emitting a sharp alarm sound or a buzzer at a specific frequency, which can attract the operator's attention in noisy environments.

[0056] Light alarms can alert to abnormal situations by flashing bright red or yellow lights, providing a direct visual reminder. They are especially suitable for scenarios with high noise levels or where staff are far from the alarm device but still within sight.

[0057] The vibration alarm function generates a vibration when the detected value exceeds the threshold, which can be promptly detected by personnel wearing relevant receiving devices (such as portable terminals worn by inspection personnel).

[0058] Of course, the alarm device can also be linked with the communication module 14 to send alarm information, such as SMS messages or pop-up reminders, to the designated management personnel's mobile phones or remote monitoring centers, thereby realizing multi-channel and all-round alarms and ensuring that the natural gas detection system can be quickly notified and dealt with when there are abnormalities in the content of tetrahydrothiophene and hydrogen sulfide.

[0059] To filter the tested natural gas, this embodiment includes an exhaust gas filtration device 15. Specifically, the exhaust gas filtration device 15 can be an activated carbon adsorption chamber. The activated carbon adsorption chamber can absorb tetrahydrothiophene and hydrogen sulfide from the natural gas, reducing their air pollution.

[0060] Since the online detection system in this embodiment is fixed, in order to avoid damage to the system from external factors, the online detection system in this embodiment also includes an explosion-proof housing 19.

[0061] Specifically, in this embodiment, the explosion-proof housing 19 can enclose all components except for the natural gas source 1, pressure reducing valve 2, flow regulating valve 3, and exhaust gas filter 15. It is understood that the display screen 12 can be fixed to the explosion-proof housing 19 by embedding it through mounting holes at corresponding positions.

[0062] Furthermore, a portion of the detection line 16, containing the tetrahydrothiophene sensor 8 and the hydrogen sulfide sensor 9, as well as a portion of the balancing line 17, can be enclosed within the gas chamber 18. The gas chamber 18 provides a relatively stable environment for the tetrahydrothiophene sensor 8, the hydrogen sulfide sensor 9, the detection line 16, and the balancing line 17. This reduces interference from external environmental factors such as airflow fluctuations, temperature changes, and humidity variations on the detection process.

[0063] The working process of the online detection system in this embodiment is as follows:

[0064] The online detection system is installed and connected to the natural gas pipeline to be tested. The first solenoid valve 4 is opened, and natural gas enters the balance pipeline 17 from the first outlet (normally open channel) of the three-way solenoid valve 5. The pressure regulating valve and the flow regulating valve 3 are adjusted to make the natural gas reach the set flow rate and pressure. At the same time, the second solenoid valve 6 and the air pump 7 are opened to pre-purge the detection pipeline 16.

[0065] After the set purging time is reached, the gas pump 7 and the second solenoid valve 6 are turned off, and the three-way solenoid valve 5 is opened. At this time, natural gas enters the detection pipeline 16 from the second outlet of the three-way solenoid valve 5. The tetrahydrothiophene sensor 8 and the hydrogen sulfide sensor 9 detect the tetrahydrothiophene and hydrogen sulfide content in the natural gas, respectively.

[0066] The control system analyzes and calculates the detection results of the tetrahydrothiophene sensor 8 and the hydrogen sulfide sensor 9, removes the interference of hydrogen sulfide, obtains the tetrahydrothiophene content, and displays the current tetrahydrothiophene content in the natural gas through the display screen 12.

[0067] If the content of tetrahydrothiophene and / or hydrogen sulfide exceeds the preset threshold of the control system, an alarm signal will be sent through the control system.

[0068] After the test is completed, close the first solenoid valve 4 and the three-way solenoid valve 5. At this time, the natural gas transmission pipeline is in the closed state. Open the gas pump 7 and the second solenoid valve 6 to purge the test pipeline 16 and remove any residual natural gas. The online testing system enters energy-saving standby mode, thus completing a full testing cycle.

[0069] The above description is a specific implementation of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present utility model, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. An online detection system for tetrahydrothiophene and hydrogen sulfide in natural gas, characterized in that, include: Natural gas source (1), used to provide the natural gas to be tested; A three-way solenoid valve (5) has an inlet and a first outlet and a second outlet respectively connected to the inlet, and the inlet is connected to the outlet of the natural gas source (1). A balancing pipeline (17) is used to balance the pressure and flow of natural gas. The inlet of the balancing pipeline (17) is connected to the first outlet of the three-way solenoid valve (5). A detection pipeline (16) is used to detect the content of tetrahydrothiophene and hydrogen sulfide in natural gas. The inlet of the detection pipeline (16) is connected to the second outlet of the three-way solenoid valve (5). A tetrahydrothiophene sensor (8) and a hydrogen sulfide sensor (9) are connected sequentially along the natural gas flow direction on the detection pipeline (16). The tetrahydrothiophene sensor (8) is used to detect the tetrahydrothiophene content of natural gas in the detection pipeline (16), and the hydrogen sulfide sensor (9) is used to detect the hydrogen sulfide content of natural gas in the detection pipeline (16). The purging pipeline is used to purge the residual natural gas in the detection pipeline (16) before and after detection; The exhaust gas filter (15) is used to filter tetrahydrothiophene and hydrogen sulfide in natural gas. The outlet of the balance pipeline (17) and the outlet of the hydrogen sulfide sensor (9) are respectively connected to the inlet of the exhaust gas filter (15).

2. The online detection system for tetrahydrothiophene and hydrogen sulfide in natural gas according to claim 1, characterized in that, The purging pipeline includes an air pump (7) and a second solenoid valve (6) connected to the outlet of the air pump (7), the outlet of the second solenoid valve (6) being connected to the inlet of the tetrahydrothiophene sensor (8).

3. The online detection system for tetrahydrothiophene and hydrogen sulfide in natural gas according to claim 2, characterized in that, The online detection system also includes a delivery pipeline connecting the outlet of the natural gas source (1) and the inlet of the three-way solenoid valve (5), and the delivery pipeline is connected in sequence to a pressure reducing valve (2), a flow regulating valve (3) and a first solenoid valve (4) along the natural gas flow direction.

4. The online detection system for tetrahydrothiophene and hydrogen sulfide in natural gas according to claim 3, characterized in that, The online detection system also includes a control system, which is connected to the first solenoid valve (4), the second solenoid valve (6), the three-way solenoid valve (5), the air pump (7), the tetrahydrothiophene sensor (8), and the hydrogen sulfide sensor (9).

5. The online detection system for tetrahydrothiophene and hydrogen sulfide in natural gas according to claim 4, characterized in that, The control system includes a main control circuit board (11), an analog signal transmission module (13) connected to the main control circuit board (11), and a communication module (14) connected to the main control circuit board (11).

6. The online detection system for tetrahydrothiophene and hydrogen sulfide in natural gas according to claim 4, characterized in that, The online detection system also includes a display screen (12), which is connected to the control system and is used to display the detection results of the tetrahydrothiophene sensor (8) and the hydrogen sulfide sensor (9).

7. The online detection system for tetrahydrothiophene and hydrogen sulfide in natural gas according to claim 4, characterized in that, The online detection system also includes an alarm device connected to the control system. The alarm device is used to issue an alarm signal when the detection value of the tetrahydrothiophene sensor (8) and / or the hydrogen sulfide sensor (9) exceeds a set threshold.

8. The online detection system for tetrahydrothiophene and hydrogen sulfide in natural gas according to claim 1, characterized in that, The exhaust gas filtration device (15) is an activated carbon adsorption chamber.

9. The online detection system for tetrahydrothiophene and hydrogen sulfide in natural gas according to claim 1, characterized in that, The online detection system also includes an explosion-proof enclosure (19).

10. The online detection system for tetrahydrothiophene and hydrogen sulfide in natural gas according to any one of claims 2-7, characterized in that, The air pump (7) is one of a micro diaphragm air pump, a small vortex air pump or an electromagnetic air pump; the three-way solenoid valve (5) is a diversion type three-way solenoid valve; and the natural gas source (1) is a natural gas pipeline.

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