Non-contact gas quantitative measurement device for natural gas pipeline

Abstract

The utility model discloses a non-contact gas quantitative measurement device for a natural gas pipeline. The non-contact gas quantitative measurement device comprises a gas treatment unit, a control unit and a detection unit which are connected in sequence, the detection unit comprises a detection pool and a quantitative measurement module cavity, and a window for laser to pass through is arranged between the detection pool and the quantitative measurement module cavity; a laser generator and a laser receiver are arranged in a cavity of the quantitative measurement module, and a reflecting mirror is arranged on the inner wall of the detection pool; and a sensor is also arranged in the detection pool. The device can detect / monitor H2S, CO2 and CH4 in the natural gas pipeline, adopts a non-contact measurement mode, has the characteristics of strong environmental adaptability, convenience in operation, high measurement accuracy, stability and no drift of the instrument, good repeatability and reproducibility of detection data and the like, reduces the safety operation risk of the natural gas pipeline, improves the integrity management level of the natural gas pipeline, and improves the safety and reliability of the natural gas pipeline. And long-period operation of an oil field is guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of oil and gas field development, in particular to a non-contact gas quantitative measurement device for natural gas pipelines. Background Art

[0002] In the future, natural gas will exceed oil to become the world's largest energy source. By 2035, the proportion of natural gas production will increase to 50%. Solid and liquid impurities and corrosive gases in natural gas affect the safe operation of pipelines. For natural gas transmission pipelines, it is necessary to detect / monitor their water dew point, H2S, CO2, and CH4 to ensure the safety of transportation. However, the current methods all involve direct contact between sensors and the medium to be detected. Since the medium to be detected contains solid and liquid impurities or acidic gases, it is very easy to cause problems such as low sensor life, zero drift, and data jump. Content of the Utility Model

[0003] The utility model provides a non-contact gas quantitative measurement device for natural gas pipelines to solve the above technical problems.

[0004] The utility model is achieved by the following technical solutions.

[0005] A non-contact gas quantitative measurement device for natural gas pipelines includes a gas processing unit, a control unit, and a detection unit connected in sequence; the detection unit includes a detection cell and a quantitative measurement module cavity, and there is a window for laser to pass through between the detection cell and the quantitative measurement module cavity; a laser generator and a laser receiver are arranged in the quantitative measurement module cavity, and a reflector is arranged on the inner wall of the detection cell; a sensor is also arranged in the detection cell.

[0006] Further, the inlet end of the gas processing unit is connected to a first pipeline, the outlet end of the gas processing unit is connected to the inlet end of the control unit through a second pipeline, and the outlet end of the control unit is communicated with the air inlet hole of the detection cell through a third pipeline.

[0007] Further, the sensors in the detection cell include a temperature sensor and a pressure sensor.

[0008] Further, the reflector is arranged on the inner wall of the detection cell opposite to the window.

[0009] Further, the gas processing unit includes an isolation ball valve, a pressure reducing valve, and a filter connected in series.

[0010] Further, the control unit includes a pressure reducing valve and a flow meter.

[0011] Further, the window is of a lens structure.

[0012] Further, an exhaust hole is arranged on the detection cell.

[0013] Furthermore, a thermoelectric cooler is also provided inside the cavity of the quantitative measurement module.

[0014] The utility model has obtained the following beneficial effects.

[0015] The utility model adopts a non-contact measurement method, which fundamentally solves the problems that the sensor has a low service life, zero drift, and data jump due to the presence of solid-liquid impurities or acidic gases in the medium to be detected. By analyzing the change in the laser light intensity before and after being absorbed by gas molecules, the utility model can perform qualitative / quantitative analysis on the gas to be measured, and realize the detection of natural gas in the pipeline. The utility model reduces the safety operation risk of the natural gas pipeline, improves the integrity management level of the natural gas pipeline, and ensures the long-term operation of the oilfield. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic structural diagram of the utility model (where the dotted arrow is the flow direction of the gas to be detected; the solid arrow is the flow direction of the sensor output signal);

[0017] Figure 2 is a schematic structural diagram of the detection unit of the utility model.

[0018] Wherein: 1. Gas processing unit; 2. Control unit; 3. Detection unit; 301. Detection cell; 302. Temperature sensor; 303 Pressure sensor; 304. Air inlet; 305. Exhaust hole; 306. Cavity of the quantitative measurement module; 307. Window; 308. Laser generator; 309. Thermoelectric cooler; 310. Laser receiver; 311. Reflecting mirror; 4. First pipeline; 5. Second pipeline; 6. Third pipeline. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] The technical solutions of the utility model will be clearly and completely described below through specific embodiments.

[0020] As Figure 1-2 shown, a non-contact gas quantitative measurement device for a natural gas pipeline includes a gas processing unit 1, a control unit 2, and a detection unit 3.

[0021] The inlet end of the gas processing unit 1 is connected to the first pipeline 4, and the outlet end is connected to the control unit 2 through the second pipeline 5. The gas processed by the gas processing unit 1 is sent to the control unit 2; the outlet end of the control unit 2 is connected to the detection unit 3 through the third pipeline 6, and the control unit 2 controls the pressure and flow rate of the gas entering the detection unit 3.

[0022] Specifically, the gas treatment unit 1 includes an isolation ball valve, a pressure reducing valve, and a filter. The isolation ball valve, the pressure reducing valve, and the filter are connected in series in sequence to achieve throttling and pressure reduction and solid-liquid separation, and send low-pressure clean gas into the control unit 2.

[0023] The control unit 2 includes a pressure reducing valve and a flow meter. The flow meter is used to feedback the flow value, and the pressure reducing valve is used to adjust the air pressure in the detection unit 3.

[0024] The detection unit 3 includes a detection cell 301, a quantitative measurement module cavity 306, a thermoelectric cooler 309, a laser generator 308, a laser receiver 310, a mirror 311, a window 307, a temperature sensor 302, and a pressure sensor 303.

[0025] An air inlet hole 304 and an air outlet hole 305 are formed on the detection cell 301. The air inlet hole 304 is communicated with the third pipeline 6; the air inlet hole 304 and the air outlet hole 305 are used for gas to enter and exit the detection cell 301.

[0026] A window 307 is provided between the detection cell 301 and the quantitative measurement module cavity 306. The window 307 is a lens structure. A laser generator 308 and a laser receiver 310 are provided in the quantitative measurement module cavity 306. A mirror 311 is provided on the inner wall of the detection cell 301, and the mirror 311 is arranged on the inner wall of the detection cell 301 opposite to the window 307. The laser beam emitted by the laser generator 308 passes through the window 307 and irradiates on the mirror 311, and the laser beam returned by the mirror 311 passes through the window 307 again and irradiates on the laser receiver 310. Preferably, the central wavelength of the laser generator 308 is 7.5 μm, the narrowest driving pulse width is 15 ns, the maximum driving pulse amplitude is 10 A, and it has explosion-proof performance characteristics. The measurement accuracy of the laser receiver 310 is not less than 35 ps, the detection range is 0-100 mm, and it has explosion-proof performance characteristics.

[0027] A thermoelectric cooler 309 is also provided in the quantitative measurement module cavity 306. The thermoelectric cooler 309 is used to cool the laser generator 8 to maintain temperature stability.

[0028] A temperature sensor 302 and a pressure sensor 303 are provided in the detection cell 301. The temperature sensor 302 and the pressure sensor 303 are used to detect the temperature and pressure inside the detection unit 3. Preferably, the signal current of the temperature sensor is 4-20 mA, the measurement range is 20-120 degrees Celsius, and it has explosion-proof performance characteristics; the working voltage range of the pressure sensor is 0-5 V, the signal current is 4-20 mA, the measurement range is 0-10 Mpa, and it has explosion-proof performance characteristics.

[0029] The first pipeline 4 of this application is connected to the natural gas main pipeline to be detected. After the gas in the main pipeline flows into the gas processing unit 1 through the first pipeline 4, the air pressure decreases and the impurities in the gas are filtered out. Then the gas enters the detection cell 301 through the second pipeline 5, the control unit 2 and the third pipeline 6. The flowmeter in the control unit 2 measures the inflowing gas. When the value of the pressure sensor 303 reaches the preset value, the valve is closed and the injection of gas into the detection cell 301 is stopped. The laser generator 308 emits near-infrared light with a specific wavelength, which penetrates the gas to be detected in the detection cell 301 through the window 307, is reflected by the mirror 311 and then passes through the window 307 again, and irradiates on the laser receiver 310. By comparing the difference between the light intensity value detected by the laser receiver 310 and the light intensity value emitted by the laser generator 308 (the change in laser light intensity before and after being absorbed by gas molecules), the gas to be detected can be qualitatively and quantitatively analyzed.

[0030] The embodiments described above are only described as the preferred embodiments of the present invention, and do not limit the concept and scope of the present invention. Without departing from the design concept of the present invention, various modifications and improvements made by ordinary engineering and technical personnel in the field to the technical solutions of the present invention should fall within the protection scope of the present invention. The technical content claimed by the present invention has been fully recorded in the claims.

Claims

1. A non-contact gas quantitative measurement device for natural gas pipelines, characterized in that: It includes a gas processing unit (1), a control unit (2), and a detection unit (3) connected in sequence; the detection unit (3) includes a detection cell (301) and a quantitative measurement module cavity (306), and there is a window (307) for laser to pass through between the detection cell (301) and the quantitative measurement module cavity (306); a laser generator (308) and a laser receiver (310) are provided in the quantitative measurement module cavity (306), and a mirror (311) is provided on the inner wall of the detection cell (301); a sensor is also provided in the detection cell (301).

2. The non-contact gas quantitative measurement device for natural gas pipelines according to claim 1, characterized in that: The inlet end of the gas processing unit (1) is connected to a first pipeline (4), the outlet end of the gas processing unit (1) is connected to the inlet end of the control unit (2) through a second pipeline (5), and the outlet end of the control unit (2) is communicated with the air inlet hole (304) of the detection cell (301) through a third pipeline (6).

3. The non-contact gas quantitative measurement device for natural gas pipelines according to claim 1, characterized in that: The sensors in the detection cell (301) include a temperature sensor (302) and a pressure sensor (303).

4. A non-contact gas quantitative measurement device for a natural gas pipeline according to claim 1, characterized in that: The mirror (311) is arranged on the inner wall of the detection cell (301) opposite to the window (307).

5. The non-contact gas quantitative measurement device for a natural gas pipeline according to claim 1, characterized in that: The gas processing unit (1) includes a globe valve, a pressure reducing valve, and a filter connected in series with each other.

6. The non-contact gas quantitative measurement device for natural gas pipelines according to claim 1, wherein: The control unit (2) includes a pressure reducing valve and a flow meter.

7. The non-contact gas quantitative measurement device for natural gas pipelines according to claim 1, characterized in that: The window (307) is of a lens structure.

8. The non-contact gas quantitative measurement device for natural gas pipelines according to claim 1, characterized in that: An exhaust hole (305) is provided on the detection cell (301).

9. The non-contact gas quantitative measurement device for natural gas pipelines according to claim 1, characterized in that: A thermoelectric cooler (309) is also provided in the quantitative measurement module cavity (306).

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