A method of priming, a method of tracing, a priming device, a tracing device and uses

Abstract

To solve the technical problems of large consumption of tracer, low effective utilization rate and serious detection interference in the prior art, embodiments of the present application provide a filling method, a tracing method, a filling device, a tracing device and application, comprising: after the internal flow field of natural gas in a natural gas pipeline is stabilized, a tracer is mixed with a gaseous phase of natural gas in an upstream natural gas pipeline at a temperature greater than or equal to a critical phase transition temperature at which the tracer changes from a liquid phase to a gaseous phase; the mixed gas obtained after the mixing is cooled in a downstream natural gas pipeline, so that the gaseous phase tracer in the mixed gas is condensed to form tracer droplets; and the tracer droplets are detected. The tracer particles in the embodiments of the present application can be more quickly and fully mixed with natural gas under gaseous conditions, effectively improving the concentration of tracer particles carried by the pipeline natural gas, and solving the problems of large consumption of tracer, low effective utilization rate and serious detection interference caused by liquid droplet filling.

Description

Technical Field

[0001] This invention relates to a dispensing method, a tracing method, a dispensing device, a tracing device, and their applications. Background Technology

[0002] When using lasers to measure gas phase velocity and flow field changes in natural gas pipelines, tracer particles need to be added to the pipeline. The tracer particles follow the gas phase flow in the pipeline, and their position coordinates are captured and recorded by a high-speed camera. Then, the particle velocity can be obtained through corresponding algorithms, and the flow state and velocity of the gas phase in the pipeline can be further calculated.

[0003] Existing particle injection devices are all external equipment connected to the main natural gas pipeline via high-pressure lines. The injection of tracer particles is then completed using the main pipeline wall or internal pipes. Several prominent problems exist in practical applications: ① External particle injection equipment has a complex structure. During use, a large amount of tracer residue adheres to the particle reactor and high-pressure pipeline, resulting in high tracer loss and low effective utilization. Furthermore, it requires repeated handling before and after testing, making it bulky and inconvenient to operate. ② Single-point injection on the outer pipe wall leads to a large amount of tracer particles adhering to the opposite pipe wall, causing secondary loss of tracer particles and rapid liquid accumulation in the downstream transparent test section, severely interfering with laser velocimetry. It also necessitates frequent depressurization and disassembly / cleaning of the high-pressure pipeline. These two problems result in high tracer consumption and low effective utilization during natural gas pipeline flow field testing, and single-point injection on the outer pipe wall is difficult and ineffective. Summary of the Invention

[0004] To address the technical problems of high tracer consumption, low effective utilization rate, and severe detection interference in existing technologies, embodiments of the present invention provide a dispensing method, a tracing method, a dispensing device, a tracing device, and its application.

[0005] The objective of this invention is achieved through the following technical solutions:

[0006] In a first aspect, embodiments of the present invention provide a method for injecting a tracer for the internal flow field of natural gas, comprising: the tracer being miscible with the gas phase of natural gas at a critical phase transition temperature greater than or equal to the critical phase transition temperature at which the tracer changes from the liquid phase to the gas phase.

[0007] Optionally, the tracer is miscible with the gas phase of natural gas at a critical phase transition temperature greater than or equal to the temperature at which the tracer changes from the liquid phase to the gas phase, including: after the internal flow field of natural gas stabilizes, the tracer is miscible with the gas phase of natural gas at a critical phase transition temperature greater than or equal to the temperature at which the tracer changes from the liquid phase to the gas phase.

[0008] Optionally, the temperature of the mixed gas obtained after gas-phase miscibility is greater than or approximately equal to the critical phase transition temperature of the tracer when it changes from the liquid phase to the gas phase.

[0009] Secondly, embodiments of the present invention provide a method for tracing the internal flow field of natural gas, comprising:

[0010] Once the internal flow field of natural gas stabilizes, the tracer becomes miscible with the gas phase of natural gas at a temperature greater than or equal to the critical phase transition temperature at which the tracer changes from liquid to gas.

[0011] The mixed gas obtained after mixing is cooled so that the gaseous tracer in the mixed gas condenses to form tracer droplets;

[0012] The tracer droplets are then traced and detected.

[0013] Thirdly, embodiments of the present invention provide a method for tracing the internal flow field of natural gas, comprising:

[0014] Once the internal flow field of natural gas in the natural gas pipeline stabilizes, the tracer becomes miscible with the gas phase of natural gas in the upstream natural gas pipeline at a temperature greater than or equal to the critical phase transition temperature at which the tracer changes from liquid to gas phase.

[0015] In the downstream natural gas pipeline, the mixed gas obtained after mixing is cooled so that the gaseous tracer in the mixed gas condenses to form tracer droplets.

[0016] The tracer droplets are then traced and detected.

[0017] Fourthly, embodiments of the present invention provide a tracer dispensing device, comprising:

[0018] A temperature unit for converting a tracer from a liquid phase to a gaseous phase; and

[0019] The injection unit is used to inject a gaseous tracer into the natural gas pipeline.

[0020] Optionally, the dispensing unit includes:

[0021] A tracer storage unit is used to store tracers and inject tracers in a gaseous state into natural gas pipelines;

[0022] The temperature unit includes:

[0023] The tracer storage unit temperature control module is used to control the temperature of the tracer storage unit.

[0024] Optionally, the dispensing unit further includes: a tracer annular injection module and a tracer pump injection module;

[0025] The tracer ring injection module includes an injection ring;

[0026] The tracer storage unit is connected to the natural gas pipeline through the filling channel of the filling ring;

[0027] The tracer pump module is used to add tracer to the tracer storage unit.

[0028] Optionally, the tracer injection module includes a tracer injection pump and a shut-off valve; the tracer injection pump is connected to the tracer storage unit via the shut-off valve.

[0029] Optionally, the tracer storage unit temperature control module includes a heating belt and a temperature controller; the heating belt is wrapped around and attached to the outer wall of the tracer storage unit; the heating belt is connected to the temperature controller.

[0030] Optionally, the temperature unit further includes: a temperature and pressure detection module and a temperature control module;

[0031] The temperature and pressure detection module is connected to the temperature control module;

[0032] The temperature and pressure detection module includes a temperature and pressure sensor, a temperature sensor, and a temperature acquisition device;

[0033] The temperature and pressure sensor, temperature sensor, and temperature acquisition device are respectively connected to the temperature control module;

[0034] The temperature and pressure sensor is installed inside the filling ring;

[0035] Both the temperature sensor and the temperature acquisition unit are installed at the injection port of the tracer storage unit.

[0036] Optionally, the temperature and pressure sensor is an explosion-proof integrated temperature and pressure sensor;

[0037] The temperature sensor is a platinum resistance temperature sensor, and the temperature acquisition device is a platinum resistance temperature acquisition device.

[0038] Fifthly, embodiments of the present invention provide a tracer for the internal flow field of natural gas, comprising: a refueling device and...

[0039] The preheating unit is used to preheat the natural gas to reduce the temperature difference between the natural gas and the tracer in the gas phase, so that the mixed gas containing the natural gas and the tracer in the gas phase remains miscible in the gas phase.

[0040] A cooling unit is used to cool the mixed gas so that the gaseous tracer in the mixed gas condenses to form tracer droplets;

[0041] The detection unit is used for the tracer droplet detection.

[0042] Optionally, the preheating unit includes:

[0043] The upstream main pipeline temperature control module, installed in the upstream natural gas pipeline, is used to preheat the natural gas within the pipeline to reduce the temperature difference between the natural gas and the gaseous tracer during miscibility; and

[0044] The cooling unit includes:

[0045] The downstream main pipeline cooling module, installed on the downstream natural gas pipeline, is used to cool the natural gas that is miscible with the gaseous tracer so that the gaseous tracer in the natural gas miscible with the gaseous tracer condenses into droplets.

[0046] Optionally, the upstream main pipeline temperature control module includes a water jacket boiler.

[0047] Sixthly, embodiments of the present invention provide a tracing method for a tracing device for a natural gas internal flow field, comprising:

[0048] The natural gas pipeline is filled with natural gas to complete the venting process;

[0049] Once the flow field inside the natural gas pipeline stabilizes, the temperature controller is activated to heat the tracer in the tracer storage unit.

[0050] The temperature sensor detects the tracer temperature parameters in real time, and the temperature controller adjusts the tracer temperature according to the temperature parameters to convert the tracer into a gas phase.

[0051] Injecting the gaseous tracer into the upstream natural gas pipeline to make the gaseous tracer miscible with the natural gas;

[0052] Cooling the downstream natural gas pipeline causes the gaseous tracer in the miscible gas to condense into droplets;

[0053] The droplets are tracer-detected.

[0054] In a seventh aspect, embodiments of the present invention provide an application of a refueling method, a tracing method, a refueling device, or a tracing device in the tracing and detection of the internal flow field of natural gas.

[0055] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0056] This invention achieves rapid miscibility between natural gas and tracers by enabling gas-phase miscibility between gas-phase tracers and natural gas, effectively increasing the concentration of tracer particles carried in pipeline natural gas. This avoids the drawbacks of droplet injection, such as high tracer consumption, low tracer utilization rate, and severe detection interference. Attached Figure Description

[0057] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0058] Figure 1 This is a schematic diagram of a method for tracing the internal flow field of natural gas.

[0059] Figure 2 This is a schematic diagram of another method for tracing the internal flow field of natural gas.

[0060] Figure 3 This is a schematic diagram of the first tracer dispensing device.

[0061] Figure 4 This is a schematic diagram of the second type of tracer dispensing device.

[0062] Figure 5 This is a schematic diagram of the third type of tracer dispensing device.

[0063] Figure 6 This is a schematic diagram of a tracer device for the internal flow field of natural gas.

[0064] Figure 7 This is a schematic diagram of the tracer method for a tracer device for the internal flow field of natural gas.

[0065] Figure 8 This is a schematic diagram of a tracer dispensing device as an example.

[0066] Figure 9 The diagram shows the structure of the temperature unit and the filling unit as an example.

[0067] Figure 10 This is a schematic diagram illustrating the connection structure between the refueling unit and the natural gas channel, serving as an example.

[0068] Figure 11 This is a schematic diagram of the tracer device as an example.

[0069] The attached diagram shows the markings and corresponding component names:

[0070] 1-Refilling unit, 11-Tracer annular injection module, 111-Stainless steel filling ring, 112-Tracer storage unit, 113-Refilling channel, 114-Visual observation window, 121-Tracer injection pump, 122-Stop valve, 2-Temperature unit, 21-Temperature and pressure detection module, 211-Temperature and pressure sensor, 212-Temperature sensor, 213-Temperature acquisition device, 22-Temperature control module, 221-Upstream main pipeline temperature control module, 222-Tracer storage unit temperature control module, 2221-Heating belt, 2222-Temperature controller, 223-Downstream main pipeline cooling module, 3-Natural gas main pipeline, 31-Upstream natural gas pipeline, 32-Downstream natural gas pipeline, 4-Tracer. Detailed Implementation

[0071] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0072] Example 1

[0073] To address the technical problems of high tracer consumption, low effective utilization rate, and severe detection interference in existing technologies, the inventors discovered that the main issue is that during the droplet injection process, the low miscibility and long mixing time between the droplets and natural gas necessitate the addition of large amounts of droplet tracer to achieve the specified detection concentration of gaseous tracer in the natural gas. Unused droplet tracer not only results in waste but also interferes with subsequent detection of tracers in the natural gas.

[0074] The inventors employed a method for adding tracers within the natural gas internal flow field. By allowing the tracer to miscibly mix with the natural gas gas phase at a temperature greater than or equal to the critical phase transition temperature at which the tracer changes from liquid to gas, the tracer particles within the pipeline rapidly and fully mix with the natural gas under gaseous conditions. This effectively increases the concentration of tracer particles carried in the pipeline natural gas, thereby effectively increasing the concentration of tracers in the natural gas and reducing the effort required to add tracers. This avoids both excessive waste of tracers and interference from unused tracers in the detection process.

[0075] To ensure more accurate test results, it is generally necessary to purge the natural gas pipeline to fill it with natural gas and stabilize the internal flow field before conducting the test.

[0076] Optionally, once the internal flow field of the natural gas is stable, the tracer is miscible with the natural gas gas phase at a critical phase transition temperature greater than or equal to the temperature at which the tracer changes from the liquid phase to the gas phase.

[0077] Generally, the temperature of natural gas is lower than that of the gaseous tracer. In order for the gaseous tracer to remain in a gaseous state after mixing, one approach is to increase the temperature of the natural gas in the pipeline, thereby reducing the temperature difference between the natural gas and the gaseous tracer. Another approach is to increase the temperature of the gaseous tracer, so that the temperature of the mixed gas after mixing with the natural gas is still higher than or equal to the critical phase transition temperature of the tracer from liquid to gas, thus ensuring that the tracer remains in a gaseous state in the mixed gas.

[0078] Optionally, the temperature of the mixed gas obtained after gas-phase miscibility is greater than or approximately equal to the critical phase transition temperature of the tracer when it changes from the liquid phase to the gas phase.

[0079] The critical phase transition temperature, which is approximately equal to the temperature at which the tracer changes from the liquid phase to the gas phase, refers to the temperature at which the gaseous tracer in the gas mixture can be maintained in the gaseous phase state.

[0080] Secondly, by applying the refueling method of the first aspect to the tracing method, this embodiment of the invention provides a tracing method for the internal flow field of natural gas, comprising:

[0081] Once the internal flow field of natural gas stabilizes, the tracer becomes miscible with the gas phase of natural gas at a temperature greater than or equal to the critical phase transition temperature at which the tracer changes from liquid to gas.

[0082] The mixed gas obtained after mixing is cooled so that the gaseous tracer in the mixed gas condenses to form tracer droplets;

[0083] The tracer droplets are then traced and detected.

[0084] refer to Figure 1 As shown, the method for tracing the internal flow field of natural gas involves the tracer being miscible with the gas phase of natural gas in the gas phase after the internal flow field of natural gas has stabilized or become stable, thereby obtaining a mixed gas of natural gas and gas phase tracer.

[0085] Natural gas flows under the action of the natural gas internal flow field. By cooling the mixed gas to make the temperature of the mixed gas lower than the critical phase transition temperature of the tracer from liquid to gas phase, the tracer becomes a droplet state. Optionally, the droplets are droplets with a particle size of (0.1~10) μm.

[0086] Finally, tracer detection is performed by detecting the motion state of the tracer droplets.

[0087] To more accurately and conveniently trace and detect natural gas in natural gas pipelines, based on the second aspect, in a third aspect, embodiments of the present invention provide a method for tracing the internal flow field of natural gas, comprising:

[0088] Once the internal flow field of natural gas in the natural gas pipeline stabilizes, the tracer becomes miscible with the gas phase of natural gas in the upstream natural gas pipeline at a temperature greater than or equal to the critical phase transition temperature at which the tracer changes from liquid to gas phase.

[0089] In the downstream natural gas pipeline, the mixed gas obtained after mixing is cooled so that the gaseous tracer in the mixed gas condenses to form tracer droplets.

[0090] The tracer droplets are then traced and detected.

[0091] refer to Figure 2 As shown, after the internal flow field of natural gas in the natural gas pipeline stabilizes, a gaseous tracer is injected into the natural gas pipeline upstream to mix with the gaseous phase of natural gas.

[0092] The downstream natural gas pipeline is cooled, and when the gaseous tracer and the natural gas mixture flow to the downstream natural gas pipeline, the gaseous tracer in the mixture condenses into tracer liquid.

[0093] At this point, the remote motion state of the tracer droplets can be used for tracer detection.

[0094] Fourthly, refer to Figure 3 As shown, an embodiment of the present invention provides a tracer dispensing device, comprising:

[0095] A temperature unit for converting a tracer from a liquid phase to a gaseous phase; and

[0096] The injection unit is used to inject a gaseous tracer into the natural gas pipeline.

[0097] The temperature unit is used to heat and control the temperature of the liquid tracer. When the liquid tracer turns into a gaseous phase, the gaseous tracer is injected into the natural gas pipeline through the injection unit. Thus, the amount of tracer used can be reduced through this injection device, thereby avoiding excessive waste of tracer and preventing interference from unused tracer to the detection.

[0098] refer to Figure 4 As shown, optionally, the dispensing unit includes:

[0099] A tracer storage unit is used to store tracers and inject tracers in a gaseous state into natural gas pipelines;

[0100] The temperature unit includes:

[0101] The tracer storage unit temperature control module is used to control the temperature of the tracer storage unit.

[0102] Therefore, the tracer storage unit temperature control module controls the temperature of the tracer storage unit to ensure that when tracer is injected into the natural gas pipeline, there is enough gaseous tracer in the tracer storage unit to be injected into the natural gas pipeline.

[0103] Optionally, the dispensing unit further includes: a tracer annular injection module and a tracer pump injection module;

[0104] The tracer ring injection module includes an injection ring;

[0105] The tracer storage unit is connected to the natural gas pipeline through the filling channel of the filling ring;

[0106] The tracer pump module is used to add tracer to the tracer storage unit.

[0107] refer to Figure 5As shown, the tracer storage unit is connected to the natural gas pipeline via a filling ring, which can optionally be a stainless steel filling ring. The tracer pump module is connected to the tracer storage unit. When the tracer in the tracer storage unit is insufficient, tracer is added into the tracer storage unit via the tracer pump module.

[0108] Optionally, the tracer injection module includes a tracer injection pump and a shut-off valve; the tracer injection pump is connected to the tracer storage unit via the shut-off valve.

[0109] The tracer injection pump is connected to the tracer storage unit via a shut-off valve.

[0110] Optionally, the tracer storage unit temperature control module includes a heating belt and a temperature controller; the heating belt is wrapped around and attached to the outer wall of the tracer storage unit; the heating belt is connected to the temperature controller.

[0111] refer to Figure 5 As shown, optionally, the temperature unit further includes a temperature and pressure detection module and a temperature control module;

[0112] The temperature and pressure detection module is connected to the temperature control module;

[0113] The temperature and pressure detection module includes a temperature and pressure sensor, a temperature sensor, and a temperature acquisition device;

[0114] The temperature and pressure sensor, temperature sensor, and temperature acquisition device are respectively connected to the temperature control module;

[0115] The temperature and pressure sensor is installed inside the filling ring;

[0116] Both the temperature sensor and the temperature acquisition unit are installed at the injection port of the tracer storage unit.

[0117] Optionally, the temperature and pressure sensor is an explosion-proof integrated temperature and pressure sensor;

[0118] The temperature sensor is a platinum resistance temperature sensor, and the temperature acquisition device is a platinum resistance temperature acquisition device.

[0119] Fifthly, embodiments of the present invention provide a tracer for the internal flow field of natural gas, comprising: the refueling device described in the fourth aspect and...

[0120] The preheating unit is used to preheat the natural gas to reduce the temperature difference between the natural gas and the tracer in the gas phase, so that the mixed gas containing the natural gas and the tracer in the gas phase remains miscible in the gas phase.

[0121] A cooling unit is used to cool the mixed gas so that the gaseous tracer in the mixed gas condenses to form tracer droplets;

[0122] The detection unit is used for the tracer droplet detection.

[0123] refer to Figure 6 As shown, a natural gas internal flow field tracing device includes a temperature unit, a filling unit, a preheating unit, a cooling unit, and a detection unit.

[0124] Optionally, the preheating unit is located in the upstream natural gas pipeline. By heating the upstream natural gas pipeline, the natural gas is preheated, thereby reducing the temperature difference between the natural gas and the gaseous tracer, and ensuring that the mixed gas containing natural gas and gaseous tracer remains in a gaseous miscible state.

[0125] Optionally, the cooling unit is located in the downstream natural gas pipeline. By cooling the downstream natural gas pipeline, the natural gas in the downstream natural gas pipeline is cooled, thereby causing the gaseous tracer in the mixed gas in the downstream natural gas pipeline to condense and form tracer droplets.

[0126] The detection unit places tracer droplets in the laser velocimetry area and uses a high-speed CCD camera to capture the image.

[0127] Optionally, the preheating unit includes:

[0128] The upstream main pipeline temperature control module, installed in the upstream natural gas pipeline, is used to preheat the natural gas within the pipeline to reduce the temperature difference between the natural gas and the gaseous tracer during miscibility; and

[0129] The cooling unit includes:

[0130] The downstream main pipeline cooling module, installed on the downstream natural gas pipeline, is used to cool the natural gas that is miscible with the gaseous tracer so that the gaseous tracer in the natural gas miscible with the gaseous tracer condenses into droplets.

[0131] Optionally, the upstream main pipeline temperature control module includes a water jacket boiler.

[0132] Sixth aspect, refer to Figure 7 As shown, an embodiment of the present invention provides a tracing method for a tracing device for the internal flow field of natural gas, comprising:

[0133] The natural gas pipeline is filled with natural gas to complete the venting process;

[0134] Once the flow field inside the natural gas pipeline stabilizes, the temperature controller is activated to heat the tracer in the tracer storage unit.

[0135] The temperature sensor detects the tracer temperature parameters in real time, and the temperature controller adjusts the tracer temperature according to the temperature parameters to convert the tracer into a gas phase.

[0136] Injecting the gaseous tracer into the upstream natural gas pipeline to make the gaseous tracer miscible with the natural gas;

[0137] Cooling the downstream natural gas pipeline causes the gaseous tracer in the miscible gas to condense into droplets;

[0138] The droplets are tracer-detected.

[0139] In a seventh aspect, embodiments of the present invention provide an application of a refueling method, a tracing method, a refueling device, or a tracing device in the tracing and detection of the internal flow field of natural gas.

[0140] Example

[0141] refer to Figure 8-11 As shown, a natural gas internal flow field tracer injection device includes an injection unit 1 and a temperature unit 2; the injection unit 1 is connected to the natural gas main pipeline 3; the injection unit 1 includes: a tracer annular injection module 11 and a tracer pump injection module, the tracer annular injection module 11 and the tracer pump injection module 12 are connected, and the tracer pump injection module injects tracer into the tracer annular injection module 11.

[0142] The tracer ring injection module 11 includes a stainless steel injection ring 111 and a tracer storage unit 112. The stainless steel injection ring 111 is connected to the natural gas main pipeline 3 by means of threads or flanges. The stainless steel injection ring 111 is designed with an inner diameter of DN100. Compared with the conventional method of directly injecting through a hole in the wall of the natural gas main pipeline, the independent stainless steel injection ring has more flexible installation position and richer injection functions and methods. The tracer storage unit 112 is installed below the stainless steel injection ring 111. The stainless steel injection ring 111 is connected to the natural gas main pipeline 3 through an injection channel 113.

[0143] To balance practicality and safety, the tracer storage unit 112 may optionally be designed as a cylindrical structure with a cross-sectional circle diameter of 80 mm, a height of 80 mm, and a pressure resistance greater than or equal to 20 MPa.

[0144] Optionally, the filling channel 113 is a dense channel similar to a honeycomb structure to ensure that the gas phase tracer particles generated after the phase change can quickly and fully enter the natural gas main pipeline.

[0145] The tracer injection module includes a tracer injection pump 121 and a shut-off valve 122; the tracer injection pump 121 is connected to the shut-off valve 122, and the shut-off valve 122 is connected to the tracer storage unit 112.

[0146] Optionally, the wall of the tracer storage unit 112 is designed with a visual observation window 114, which can monitor the tracer liquid level and phase change state in real time. When the tracer liquid level drops to the warning limit, tracer can be replenished to the tracer storage unit 112 in a timely manner, and the amount of tracer injected can be controlled through the shut-off valve 122.

[0147] Optionally, the temperature control module includes a tracer storage unit temperature control module 222; the tracer storage unit temperature control module 222 is installed in the tracer storage unit 112. Optionally, the tracer storage unit temperature control module 222 includes a heating belt 2221 and a temperature controller 2222; the heating belt 2221 is tightly wrapped and attached to the outer wall of the tracer storage unit 112 to ensure heating efficiency.

[0148] Optionally, the temperature unit 2 includes a temperature and pressure detection module 21 and a temperature control module 22, wherein the temperature and pressure detection module 21 is connected to the temperature control module 22.

[0149] Optionally, the temperature and pressure detection module 21 includes a temperature and pressure sensor 211, a temperature sensor 212, and a temperature acquisition device 213; the temperature and pressure sensor is a patch type and is installed inside the stainless steel filling ring 111; the temperature sensor 212 and the temperature acquisition device 213 are patch type and are installed at the injection port of the tracer storage unit 112, on the side surface of the tube wall of the tracer storage unit 112, near the bottom surface, and are completely immersed in the liquid tracer during the test, making the temperature monitoring more accurate.

[0150] A tracer device with a built-in tracer in the internal flow field of natural gas includes the above-mentioned filling device, as well as a preheating unit and a cooling unit.

[0151] refer to Figure 11 As shown, the temperature control module 22 includes three independent temperature control systems: an upstream main pipeline temperature control module 221 (heating unit), a tracer storage unit temperature control module 222, and a downstream main pipeline cooling module 223 (cooling unit). The upstream main pipeline temperature control module 221 is installed on the upstream natural gas pipeline 31, the tracer storage unit temperature control module 222 is installed on the tracer storage unit 112, and the downstream main pipeline cooling module 223 is installed on the downstream natural gas pipeline 32.

[0152] Optionally, the upstream main pipeline temperature control module 221 uses a water jacket furnace for heating to preheat the natural gas in the upstream natural gas pipeline 31, reducing the temperature difference between the natural gas in the main pipeline and the gas phase tracer particles, thereby reducing the heat exchange between the natural gas and the gas phase tracer particles and promoting the uniform mixing of the two gases.

[0153] Optionally, the downstream main pipeline cooling module 223 cools down the upstream fully mixed natural gas, and the tracer particles carried in the natural gas recondense to form droplets with a diameter of (0.1~10) μm. The droplets flow downstream with the natural gas and enter the laser velocimetry area, where they are captured by a high-speed CCD camera.

[0154] Taking water, the most commonly used tracer for flow field testing in natural gas pipelines, as an example, this device has a built-in tracer storage unit 112. A fixed amount of water is pumped in before the experiment. During the test, the water is heated by the temperature controller 2222 to convert it into steam. The steam and natural gas are both in the gas phase, which can achieve full miscibility. In contrast, conventional injection requires particle generation outside the natural gas pipeline first, and then the atomized water droplets are sprayed into the main natural gas pipeline through high-pressure pipelines and nozzles to initially complete the mixing with natural gas. Compared with the conventional method, the new built-in heating injection method not only eliminates the complex and bulky external injection device, but also reduces the loss of tracer in the particle reactor and high-pressure pipeline. At the same time, unlike the traditional droplet injection method, the tracer particles can mix with natural gas more quickly and fully in the gaseous state, and then gradually condense into small droplets in the downstream pipeline as the temperature decreases, which is convenient for CCD cameras to capture and photograph.

[0155] The specific operation process of the aforementioned tracer device includes first opening the shut-off valve 122, injecting a quantitative amount of tracer 4 into the tracer storage unit 112 via the injection pump 121, and then closing the shut-off valve 122. Next, the heating tape 2221 is tightly wrapped and adhered to the outer wall of the tracer storage unit 112, with one end of the tape 2221 connected to the temperature controller 2222. Simultaneously, the upstream pipeline valve is opened to allow natural gas to fill the main pipeline 3, completing the venting process. Once the flow field within the main pipeline 3 stabilizes, the temperature controller 2222 is activated to heat the tracer 4, and the temperature parameters of the tracer 4 are monitored in real time by the temperature sensor 212 for temperature control adjustments. When the critical phase transition temperature is reached, the tracer 4 is largely converted into a gaseous state, and experimental testing can begin.

[0156] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for injecting a tracer for the internal flow field of natural gas, characterized in that, include: The tracer is miscible with the gas phase of natural gas at a temperature greater than or equal to the critical phase transition temperature at which the tracer changes from the liquid phase to the gas phase; The tracer is miscible with the gas phase of natural gas at a critical phase transition temperature greater than or equal to the temperature at which the tracer changes from the liquid phase to the gas phase, including: after the internal flow field of natural gas stabilizes, the tracer is miscible with the gas phase of natural gas at a critical phase transition temperature greater than or equal to the temperature at which the tracer changes from the liquid phase to the gas phase. The temperature of the mixed gas obtained after gas phase miscibility is greater than or approximately equal to the critical phase transition temperature of the tracer from liquid phase to gas phase. The mixed gas obtained after gas-phase miscibility is cooled so that the gas-phase tracer in the mixed gas condenses to form tracer droplets; the tracer droplets are used for tracer detection.

2. A method for tracing the internal flow field of natural gas, characterized in that, include: Once the internal flow field of natural gas stabilizes, the tracer becomes miscible with the gas phase of natural gas at a temperature greater than or equal to the critical phase transition temperature at which the tracer changes from liquid to gas. The mixed gas obtained after mixing is cooled to cause the gaseous tracer in the mixed gas to condense into tracer droplets; the tracer droplets are then detected.

3. A method for tracing the internal flow field of natural gas, characterized in that, include: Once the internal flow field of natural gas in the natural gas pipeline stabilizes, the tracer is miscible with the gas phase of natural gas in the upstream natural gas pipeline at a critical phase transition temperature greater than or equal to that at which the tracer changes from liquid to gas phase. In the downstream natural gas pipeline, the mixed gas obtained after miscibility is cooled to condense the gas phase tracer in the mixed gas into tracer droplets. The tracer droplets are then detected.

4. A tracer dispensing device, wherein the tracer dispensing method of claim 1 is applied to the dispensing device, characterized in that, include: Temperature unit, used to convert tracer in liquid phase to tracer in gas phase; And a refueling unit for injecting gaseous tracers into natural gas pipelines.

5. The tracer dispensing device as described in claim 4, characterized in that, The refueling device is used in the internal flow field tracing and detection of natural gas.

6. The tracer dispensing device as described in claim 4, characterized in that, The injection unit includes: a tracer storage unit for storing tracers and injecting tracers in a gaseous state into the natural gas pipeline; the temperature unit includes: a tracer storage unit temperature control module for controlling the temperature of the tracer storage unit.

7. The tracer dispensing device as described in claim 6, characterized in that, The refueling unit further includes: a tracer ring injection module and a tracer pump injection module; the tracer ring injection module includes a refueling ring; the tracer storage unit is connected to a natural gas pipeline through the refueling channel of the refueling ring; the tracer pump injection module is used to refuel the tracer into the tracer storage unit.

8. The tracer dispensing device as described in claim 7, characterized in that, The tracer injection module includes a tracer injection pump and a shut-off valve; the tracer injection pump is connected to the tracer storage unit through the shut-off valve.

9. The tracer dispensing device as described in claim 6, characterized in that, The tracer storage unit temperature control module includes a heating belt and a temperature controller; the heating belt is wrapped around and attached to the outer wall of the tracer storage unit; the heating belt is connected to the temperature controller.

10. The tracer dispensing device according to any one of claims 6-9, characterized in that, The temperature unit further includes a temperature and pressure detection module and a temperature control module; the temperature and pressure detection module is connected to the temperature control module; the temperature and pressure detection module includes a temperature and pressure sensor, a temperature sensor, and a temperature acquisition device; the temperature and pressure sensor, the temperature sensor, and the temperature acquisition device are respectively connected to the temperature control module; the temperature and pressure sensor is installed inside the filling ring; the temperature sensor and the temperature acquisition device are both installed at the tracer storage unit injection port.

11. The tracer dispensing device as described in claim 10, characterized in that, The temperature and pressure sensor is an explosion-proof integrated temperature and pressure sensor; the temperature sensor is a platinum resistance temperature sensor, and the temperature acquisition device is a platinum resistance temperature acquisition device.

12. A tracer device for the internal flow field of natural gas, characterized in that, include: The refueling device and preheating unit according to any one of claims 4-11 are used to preheat natural gas to reduce the temperature difference between natural gas and tracer in gas phase state, so that the mixed gas containing natural gas and tracer in gas phase state is maintained in gas phase miscibility. A cooling unit is used to cool the mixed gas so that the gaseous tracer in the mixed gas condenses to form tracer droplets; a detection unit is used to detect the tracer droplets.

13. The tracer device as claimed in claim 12, characterized in that, The preheating unit includes: an upstream main pipeline temperature control module, installed in the upstream natural gas pipeline, used to preheat the natural gas in the natural gas pipeline to reduce the temperature difference between the natural gas and the gaseous tracer when they are miscible; and the cooling unit includes: a downstream main pipeline cooling module, installed in the downstream natural gas pipeline, used to cool the natural gas that is miscible with the gaseous tracer so that the gaseous tracer in the natural gas that is miscible with the gaseous tracer condenses into droplets.

14. The tracer device as claimed in claim 13, characterized in that, The upstream main pipeline temperature control module includes a water jacket boiler.

15. A tracing method for a tracing device for the internal flow field of natural gas, characterized in that, include: The natural gas pipeline is filled with natural gas to complete the venting process. Once the flow field inside the natural gas pipeline stabilizes, the temperature controller is activated to heat the tracer in the tracer storage unit. The temperature parameters of the tracer are monitored in real time by a temperature sensor, and the temperature controller adjusts the temperature of the tracer according to the temperature parameters to convert the tracer into a gaseous phase. The gaseous tracer is injected into the upstream natural gas pipeline to make the gaseous tracer miscible with the natural gas. The downstream natural gas pipeline is cooled to condense the gaseous tracer in the miscible gas into droplets. The droplets are then tracer-detected.

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