System and method for measuring temperature and phase state of medium in pipe

Abstract

The invention discloses a system and method for measuring the temperature and phase state of a medium in a pipe, and the system comprises a plurality of groups of temperature measurement devices which are respectively disposed at different positions in the axial direction of a to-be-measured pipeline, and each group of temperature measurement devices is provided with a plurality of temperature measurement elements which are uniformly disposed at different positions in the diameter direction of the section of the corresponding pipeline. Each temperature measuring element is used for measuring the temperature of the medium in the pipe at the corresponding position; the pressure sensor is arranged on the side wall of the section of the corresponding pipeline and is used for measuring the pressure of a medium in the pipeline; and the data processing device is used for collecting the medium temperature measured by each temperature measuring element and the medium pressure measured by the pressure sensor in real time, and on the basis, phase state changes and two-dimensional temperature distribution rules of media in different pipes are formed. According to the invention, the change data of the two-dimensional temperature and the phase state is obtained, and the change condition of the characteristics of the medium in the pipe during CO2 leakage is displayed more comprehensively.

Description

Technical Field

[0001] The present invention relates to the technical field of pipeline leakage measurement, and particularly to a measurement device and method for the two-dimensional temperature and phase state distribution of the medium in a CO2 pipeline. Background Art

[0002] CO2 is a major greenhouse gas. Carbon capture, utilization, and storage technology (CCUS) is one of the current effective means to mitigate global warming. The transportation of CO2 is an important node in CCUS technology, and pipelines are currently the most economical and reliable way to transport CO2. During the operation of long-distance pipelines, there is an inevitable risk of leakage. Once a leakage occurs, the temperature of the CO2 drops rapidly after flowing through the leakage point, which may cause the pipeline temperature to be lower than the design temperature, making the pipeline face brittle fracture and posing a huge safety hazard. In addition, the leaked CO2 will accumulate in the low-lying areas downstream of the leakage point and is not easily detectable. When the concentration is high, it will cause harm to personnel, crops, and the surrounding environment. To scientifically construct the CO2 pipeline transportation process and safety operation methods, develop CO2 risk assessment technology, and comprehensively promote the development of CCUS technology, it is necessary to deeply understand the risk characteristics during the CO2 pipeline leakage process.

[0003] In the prior art, relevant research is mainly carried out through high-pressure CO2 pipeline leakage experiments, and several thermocouples and pressure sensors are arranged on the pipeline to obtain the parameters of the medium inside the pipeline during the leakage pressure reduction process. The existing measurement of the temperature inside the pipeline mainly focuses on the temperature distribution along the axial direction of the pipeline and the temperature measurement at the top and bottom of the pipeline, resulting in the temperature distribution in a single dimension. Therefore, the two-dimensional distribution of temperature and phase state during the leakage process cannot be obtained, and even the interface of the gas-liquid two-phase or gas-liquid-solid three-phase cannot be obtained. This makes it difficult to effectively study the pipeline temperature distribution, phase change path, change of the gas-liquid interface, and determination of the dry ice generation position during the CO2 pipeline leakage pressure reduction process.

[0004] In summary, aiming at the problem that the current research on the characteristics of the medium inside the high-pressure CO2 pipeline during leakage is not sufficient, the prior art urgently needs to develop an experimental device and method that can conduct research on the two-dimensional temperature measurement inside the CO2 pipeline and reveal the two-dimensional phase change and distribution inside the pipeline, so as to scientifically evaluate the risk characteristics during pipeline leakage. Summary of the Invention

[0005] The purpose of the present invention is to propose a technical solution that can comprehensively measure the temperature and phase state of the medium inside the CO2 pipeline in view of the problems of being unable to measure the two-dimensional temperature change inside the CO2 pipeline and the incomplete detection of the temperature phase state of the CO2 pipeline.

[0006] To solve the above technical problems, an embodiment of the present invention provides a system for measuring the temperature and phase state of the medium in a pipe, including: multiple groups of temperature measurement devices respectively arranged at different positions in the axial direction of the pipeline to be measured, each group of temperature measurement devices having a plurality of temperature measurement elements uniformly arranged at different positions in the diameter direction of the corresponding pipeline cross-section, and each temperature measurement element is used to measure the temperature of the medium in the pipe at the corresponding position; a pressure sensor arranged on the side wall of the corresponding pipeline cross-section for measuring the pressure of the medium in the pipe; a data processing device for real-time collecting the medium temperature measured by each temperature measurement element and the medium pressure measured by the pressure sensor, and based on this, forming the phase change and two-dimensional temperature distribution law of different media in the pipe.

[0007] Preferably, in the system, the temperature measurement device includes: a metal rod installed on the inner wall of the pipe along the diameter direction of the pipeline cross-section, and the metal rod is configured with a hollow cavity for installing the plurality of temperature measurement elements; a first joint for respectively fixing the two ends of the metal rod on the side wall of the pipe.

[0008] Preferably, in the system, at least two relatively arranged first grooves are formed on the side wall of the pipe, and the first grooves are used as installation positions for inlaying and fixing the two ends of the metal rod on the side wall of the pipe through the first joint.

[0009] Preferably, in the system, a plurality of holes are formed on the metal rod, so that the hollow cavity is communicated with the internal space of the pipe. Among them, the temperature measurement element is implemented by a thermocouple probe, and each thermocouple probe passes through the corresponding hole to contact the external space of the metal rod.

[0010] Preferably, in the system, the signal transmission wire of each thermocouple probe is led out through the first end of the metal rod and connected to the data processing device.

[0011] Preferably, in the system, the system further includes: a second joint for inlaying the pressure sensor on the side wall of the pipe; a second groove formed on the side wall of the pipe, and used as an installation position for inlaying and fixing the pressure sensor on the side wall of the pipe through the second joint.

[0012] Preferably, for the system, the data processing device includes: a plurality of data acquisition boxes corresponding to each group of temperature measurement devices respectively, each data acquisition box being connected in a cascaded manner, each data acquisition box being configured to collect real-time medium temperature data groups of different pipeline heights at different measurement times from the corresponding group of temperature measurement devices, as well as collect real-time medium pressure data of each pipeline cross-section; a computing terminal, which is configured to obtain the real-time medium temperature data groups and the real-time medium pressure data from different data acquisition boxes, generate phase diagrams of different pipeline cross-sections, and two-dimensional temperature change laws formed at different pipeline heights of different pipeline cross-sections, and based on this, identify the formation time and formation position of different phases of the medium in the pipeline, where the different phases include but are not limited to gas phase, liquid phase, solid phase, supercritical phase, and dense liquid phase.

[0013] Preferably, for the system, the plurality of data acquisition boxes are configured as one main acquisition box and several slave acquisition boxes, where the main acquisition box is directly connected to the computing terminal, and the other acquisition boxes except the main acquisition box are slave acquisition boxes. Among them, the main acquisition box is equipped with a first protection device and an embedded real-time controller disposed inside the first protection device. The embedded real-time controller is configured to transmit the real-time medium temperature data groups and the real-time medium pressure data from each slave acquisition box, as well as the real-time medium temperature data groups and the real-time medium pressure data collected by itself, to the computing terminal; each slave acquisition box is equipped with a second protection device and an Ethernet expansion chassis disposed inside the second protection device. Each Ethernet expansion chassis is configured to transmit the real-time medium temperature data groups and the real-time medium pressure data collected by itself to the embedded real-time controller through a plurality of Ethernet expansion chassis inside the slave acquisition boxes connected between its own chassis and the embedded real-time controller.

[0014] Preferably, for the system, the various data acquisition boxes are connected to each other through Ethernet cables, and the main acquisition box is connected to the computing terminal through an Ethernet cable.

[0015] Preferably, for the system, the system is applied to the leakage detection experiment of a specific medium pipeline, where the specific medium pipeline is a carbon dioxide pipeline.

[0016] On the other hand, the present invention also proposes a method for measuring the temperature and phase state of the medium in a pipe. The method is implemented by using the system as described above. The method includes: arranging multiple groups of temperature measurement devices at different positions in the axial direction of the pipeline to be measured, and arranging corresponding pressure sensors on the side walls of different pipeline cross-sections. Among them, each group of temperature measurement devices has multiple temperature measurement elements uniformly arranged at different positions in the diameter direction of the corresponding pipeline cross-section; using each temperature measurement element in each group of temperature measurement devices to measure the temperature of the medium in the pipe at the corresponding position; using the pressure sensors on different pipeline cross-sections to measure the pressure of the medium in the pipe; using a data processing device to collect in real time the medium temperature measured by each temperature measurement element and the medium pressure measured by the pressure sensors, and based on this, forming the phase state change and two-dimensional temperature distribution law of different media in the pipe.

[0017] Preferably, the method is applied to the flow discharge detection experiment of a specific medium pipeline, where the specific medium pipeline is a carbon dioxide pipeline.

[0018] Compared with the prior art, one or more of the above embodiments may have the following advantages or beneficial effects:

[0019] The present invention proposes a system and a method for measuring the temperature and phase state of the medium in a pipe. On the basis of measuring the one-dimensional temperature and phase state change of the medium in the pipe in the traditional technology, the present invention combines the measurement of the temperature on the vertical cross-section in the pipe to monitor the two-dimensional temperature and phase state change in the pipe, and improves the problem of incomplete measurement of the medium in the conduit in the traditional technology.

[0020] Other features and advantages of the present invention will be described in the following specification, and, in part, will be obvious from the specification, or will be understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained by the structures specifically pointed out in the specification, the claims, and the drawings. Description of the Drawings

[0021] The drawings are used to provide a further understanding of the present invention, and constitute a part of the specification. They are used together with the embodiments of the present invention to explain the present invention, and do not constitute a limitation to the present invention. In the drawings:

[0022] Figure 1 It is a schematic diagram of the overall structure of the system for measuring the temperature and phase state of the medium in the pipeline to be measured according to the embodiment of the present application.

[0023] Figure 2 It is a schematic diagram of the specific structure of the temperature measurement device in the system for measuring the temperature and phase state of the medium in the pipeline to be measured according to the embodiment of the present application.

[0024] Figure 3Schematic diagram of the specific structure of the temperature measurement device and the pressure sensor in the transverse section of the pipeline in the system for measuring the temperature and phase state of the medium in the pipeline to be measured according to the embodiment of the present application.

[0025] Figure 4 Schematic diagram of the steps of the method for measuring the temperature and phase state of the medium in the pipeline to be measured according to the embodiment of the present application.

[0026] Figure 5 Schematic diagram of the steps for calibrating the device before the leakage experiment in the method for measuring the temperature and phase state of the medium in the pipeline to be measured according to the embodiment of the present application.

[0027] Figure 6 Diagram of the two-dimensional change and distribution law of the temperature of the medium in the pipeline at different times in an embodiment of the system for measuring the temperature and phase state of the medium in the pipeline to be measured according to the embodiment of the present application.

[0028] Figure 7 Diagram of the two-dimensional change and distribution law of the temperature and phase state of the medium in the pipeline at different times in an embodiment of the system for measuring the temperature and phase state of the medium in the pipeline to be measured according to the embodiment of the present application.

[0029] In the present application, all the drawings are schematic drawings, only used to illustrate the principle of the present invention and not drawn according to the actual scale.

[0030] Among them, the list of reference numerals is as follows:

[0031] 1. Thermocouple wire

[0032] 2. First joint

[0033] 3. Thermocouple probe

[0034] 4. Metal rod

[0035] 5. Second joint

[0036] 6. Pressure sensor

[0037] 7. Pipe wall

[0038] 8. Temperature measurement structure

[0039] 9. First groove

[0040] 10. Calculation terminal

[0041] 11. Acquisition box

[0042] 12. Ethernet cable

[0043] 13. Pipeline

[0044] 15. Second groove

[0045] 16. First protection device

[0046] 17. Embedded real-time controller

[0047] 18. Second protection device

[0048] 19. Ethernet expansion chassis

[0049] 20. Temperature measurement device

[0050] 21. Temperature measurement element

[0051] 30. Data processing device Detailed implementation manners

[0052] The embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings and embodiments, so as to fully understand how the present invention uses technical means to solve technical problems and the implementation process of achieving technical effects and implement accordingly. It should be noted that as long as there is no conflict, the various embodiments in the present invention and the various features in each embodiment can be combined with each other, and the formed technical solutions are all within the protection scope of the present invention.

[0053] In addition, the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. And although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than here.

[0054] The terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments. Unless the context clearly indicates otherwise, the singular forms "a" and "an" used herein are also intended to include the plural. It should also be understood that the terms "comprise" and / or "include" used herein specify the presence of the stated features, integers, steps, operations, units and / or components, and do not exclude the presence or addition of one or more other features, integers, steps, operations, units, components and / or combinations thereof.

[0055] CO2 is the main greenhouse gas. Carbon capture, utilization, and storage technology (CCUS) is one of the current effective means to alleviate global warming. The transportation of CO2 is an important node in CCUS technology, and pipelines are currently the most economical and reliable way to transport CO2. Long-distance pipelines inevitably have leakage risks during operation. Once a leakage occurs, the temperature of CO2 drops rapidly after flowing through the leakage port, which may cause the pipeline temperature to be lower than the design temperature, making the pipeline face brittle fracture and posing a huge safety hazard. In addition, the leaked CO2 will accumulate in the low-lying areas downstream of the leakage port and is not easily detectable. When the concentration is high, it will harm personnel, crops, and the surrounding environment. To scientifically construct the CO2 pipeline transportation process and safety operation methods, develop CO2 risk assessment technology, and comprehensively promote the development of CCUS technology, it is necessary to deeply understand the risk characteristics during the CO2 pipeline leakage process.

[0056] In the prior art, relevant research is mainly carried out through high-pressure CO2 pipeline leakage experiments, and several thermocouples and pressure sensors are arranged on the pipeline to obtain the parameters of the medium inside the pipe during the leakage pressure reduction process. The existing measurement of the temperature inside the pipe mainly focuses on the temperature distribution along the axial direction of the pipeline and the temperature measurement at the top and bottom of the pipeline, resulting in the temperature distribution in a single dimension. Therefore, the two-dimensional distribution of temperature and phase state during the leakage process cannot be obtained, let alone the interface of the gas-liquid two-phase or even gas-liquid-solid three-phase. This makes it difficult to effectively study the temperature distribution of the pipeline, the phase change path, the change of the gas-liquid interface, and the discrimination of the dry ice generation position during the CO2 pipeline leakage pressure reduction process.

[0057] To solve the above problems, the present invention proposes a system and method for measuring the temperature and phase state of the medium inside the pipe. This system and method use temperature measurement devices set at different positions of the pipeline to detect the temperature of the medium in the vertical direction of the pipeline. Compared with the traditional technology that can only obtain the temperature change data of the medium along the axial direction of the pipeline, this solution can simultaneously obtain the temperature change law in the vertical direction and the temperature change law in the horizontal direction, that is, the two-dimensional temperature change law of the medium inside the pipe. Moreover, based on the two-dimensional temperature change law and the pressure data measured by the pressure sensor, the present invention can obtain the change law of the two-dimensional temperature and phase state inside the pipe.

[0058] Example 1

[0059] Figure 1 This is the overall structural schematic diagram of the system for measuring the temperature and phase state of the medium inside the pipe in the embodiments of the present application. As Figure 1As shown, the system for measuring the temperature and phase state of the medium inside the pipe (also referred to as the "in-pipe measurement system") according to the embodiment of the present invention includes: a temperature measurement device 20, a pressure sensor 6, and a data processing device 30. In one embodiment, this in-pipe measurement system is applied to the leakage detection experiment of a specific medium pipeline. Among them, the specific medium pipeline is a carbon dioxide pipeline.

[0060] Figure 3 It is a specific structural schematic diagram of the temperature measurement device and the pressure sensor in the cross-section of the pipeline in the system for measuring the temperature and phase state of the medium inside the pipe to be measured according to the embodiment of the present application. As Figure 3 shown, multiple groups of temperature measurement devices 20 are respectively arranged at different positions in the axial direction of the pipeline to be measured. Each group of temperature measurement devices 20 has a plurality of temperature measurement elements 21 uniformly arranged at different positions in the diameter direction of the corresponding pipeline cross-section. Among them, each temperature measurement element 21 is used to measure the temperature of the medium inside the pipe at the corresponding position.

[0061] As Figure 1 shown, the pressure sensor 6 is arranged at the side wall of the corresponding pipeline cross-section for measuring the pressure of the medium inside the pipe. The data processing device 30 is used to collect in real time the medium temperature measured by each temperature measurement element 21 and the medium pressure measured by the pressure sensor 6, and form the phase change and two-dimensional temperature distribution law of different media inside the pipe according to the medium temperature in the diameter direction of each pipeline cross-section and the medium pressure on each pipeline cross-section.

[0062] Specifically, multiple groups of temperature measurement devices 20 are respectively arranged at different positions in the axial direction of the pipeline to be measured, and the temperature change of the cross-sections where each temperature measurement device 20 is located in the axial direction of the pipeline can be obtained. Each group of temperature measurement devices 20 also has a plurality of temperature measurement elements 21 uniformly arranged at different positions in the diameter direction of the corresponding pipeline cross-section, and the temperature change in the vertical direction of the cross-section where the temperature measurement device 20 is located can be obtained. In this way, after the embodiment of the present invention can measure the temperature change data in the axial direction and the temperature change data in the vertical direction of different axial interfaces, the two-dimensional temperature change law of the medium inside the pipe can be obtained.

[0063] Figure 2 It is a specific structural schematic diagram of the temperature measurement device in the system for measuring the temperature and phase state of the medium inside the pipe to be measured according to the embodiment of the present application. As Figure 2As shown, in one embodiment, the temperature measurement device 20 includes a metal rod 4 and a first joint 2. The metal rod 4 is installed along the diameter direction of the cross-section on the inner wall of the pipeline. Among them, the metal rod 4 is configured with a cavity for installing a plurality of temperature measurement elements 21. The first joint 2 is used to fix the two ends of the metal rod 4 on the inner wall of the pipeline respectively. Further, at least two relatively arranged first grooves 14 are formed on the side wall of the pipeline. The first groove 14 is used as an installation position for inlaying and fixing the two ends of the metal rod 4 on the pipe wall 7 through the first joint 2. Specifically, the metal rod 4 is vertically installed inside the pipeline, and the temperature change in the vertical direction at this cross-section inside the pipe can be measured. The first joint 2 is arranged at both ends of the metal rod 4 to fix the metal rod 4 and prevent the metal rod 4 from deforming when gas leaks, etc., which affects the temperature measurement of the medium inside the pipe. And, the first groove 14 is designed to be inlaid and welded inside the pipeline, facilitating the later maintenance and replacement of the temperature measurement device and reducing the pressure of maintaining the pipeline later.

[0064] Further, a plurality of holes are formed on the metal rod 4, so that the hollow cavity is connected to the internal space of the pipeline. Among them, in one embodiment, the temperature measurement element 21 is implemented by a thermocouple probe 3, and each thermocouple probe 3 passes through the corresponding hole to contact the medium in the external space of the metal rod 4. Further, the signal transmission wire of each thermocouple probe 3 is led out through the first end of the metal rod 4 and connected to the data processing device 30. Specifically, the hollow cavity of the metal rod 4 is connected to the internal space of the pipeline, and the signal transmission wire of each thermocouple probe 3 is led out through the first end of the metal rod 4 and connected to the data processing device 30. The thermocouple probes 3 arranged on the same metal rod 4 are all in parallel, and the thermocouple probes 3 arranged on the same metal rod 4 can realize synchronous acquisition of temperature data.

[0065] Additionally, as Figure 3 shown, the system for measuring the temperature and phase state of the medium inside the pipe according to the embodiment of the present invention further includes a second joint 5 and a second groove 15. The second joint 5 is used to inlay the pressure sensor 6 on the pipe wall 7. The second groove is formed on the pipe wall 7 and is used as an installation position for inlaying and fixing the pressure sensor 6 on the side wall of the pipeline through the second joint 5. Specifically, the pressure sensor 6 is arranged at the side wall of the pipeline cross-section corresponding to the position of the temperature measurement device 20, and the pressure change data at this cross-section can be obtained. The second groove 15 is designed to be inlaid and welded on the side wall of the pipeline, facilitating the later replacement and maintenance of the pressure sensor 6.

[0066] Specifically, the data processing device includes: a plurality of acquisition boxes 11 and a computing terminal 10. Each acquisition box 11 is connected in a cascaded manner and is used to collect real-time medium temperature data groups at different pipe heights of the corresponding group of temperature measuring devices 20 at different measurement times, and to collect real-time medium pressure data of each pipe cross-section. Specifically, each acquisition box 11 corresponds to each temperature measuring device 20 and the pressure sensor 6 at the same cross-section position.

[0067] It should be noted that in the embodiments of the present invention, a plurality of temperature measuring devices 20 are arranged at a certain distance according to the risk assessment situation in the pipe. Similarly, a corresponding number of acquisition boxes 11 need to be set. The acquisition boxes 11 are connected in a cascaded manner, which more effectively reduces the cost in the actual application process compared to each acquisition box 11 being separately connected to the computing terminal 10.

[0068] The computing terminal 10 is used to obtain the real-time medium temperature data groups and real-time medium pressure data from different acquisition boxes 11, generate phase diagrams of different pipe cross-sections, and two-dimensional temperature change laws formed at different pipe heights of different pipe cross-sections, and identify the formation time and formation position of different phases of the medium in the pipe according to the generated phase diagrams and two-dimensional temperature change laws. In the embodiments of the present invention, different phases include, but are not limited to: gas phase, liquid phase, solid phase, supercritical phase, and dense liquid phase.

[0069] In this way, the computing terminal 10 generates a two-dimensional temperature and phase change law diagram of the medium in the pipe according to the obtained temperature data and pressure data, which is more conducive to the staff to more intuitively judge the phase situation of the medium in the pipe.

[0070] Furthermore, the plurality of acquisition boxes 11 are configured as a main acquisition box and several slave acquisition boxes. Among them, the main acquisition box is directly connected to the computing terminal 10, and the other acquisition boxes except the main acquisition box are all slave acquisition boxes. Further, the main acquisition box is provided with a first protection device 16 and an embedded real-time controller 17 arranged inside the first protection device. The embedded real-time controller 17 is used to transmit the real-time medium temperature data groups and real-time medium pressure data from each slave acquisition box, as well as the real-time medium temperature data groups and real-time medium pressure data collected by itself, to the computing terminal 10.

[0071] Furthermore, each slave acquisition box is provided with a second protection device 18 and an Ethernet expansion chassis 19 arranged inside the second protection device. Each Ethernet expansion chassis 19 is used to transmit the real-time medium temperature data groups and real-time medium pressure data collected by itself to the embedded real-time controller 17 through the Ethernet expansion chassis 19 in several slave acquisition boxes connected between its own chassis and the embedded real-time controller 17.

[0072] Specifically, the main acquisition box and each slave acquisition box are respectively equipped with a first protection device 16 and a second protection device 18, while the internal control devices of each acquisition box 11 are different. The embedded real-time controller 17 inside the main acquisition box transmits the data transmitted from the slave acquisition boxes and the data collected by itself to the computing terminal 10. The slave acquisition boxes are connected in cascade, so that the Ethernet expansion chassis 19 inside the slave acquisition boxes transmits the data in several slave acquisition boxes to the main acquisition box in a cascaded form.

[0073] Furthermore, each acquisition box 11 is connected by an Ethernet cable 12, and the main acquisition box and the computing terminal 10 are also connected by an Ethernet cable 12. Using the Ethernet cable 12 for signal transmission has higher economic applicability and more reliable data transmission ability compared with traditional technologies.

[0074] Example 2

[0075] Based on the above Embodiment 1, an embodiment of the present invention provides a specific embodiment of a system for measuring the temperature and phase state of a medium in a pipe.

[0076] The in-pipe measurement system includes: a temperature measurement device 20, a pressure sensor 6, and a data processing device 30. Among them, the temperature measurement device 20 includes a metal rod 4 and a first joint 2. The data processing device 30 includes an acquisition box 11 and a computing terminal 10. Among them, the acquisition box 11 includes a main acquisition box and several slave acquisition boxes. In the process of realizing the measurement of the temperature and phase state of the medium in the pipe, the above system can be used to measure the temperature and phase state of the medium in the CO2 pipeline, and obtain a more comprehensive change situation of the real temperature and phase state in the pipe.

[0077] In one embodiment, specifically, as Figure 2 shown, the temperature measurement device 20 includes: thermocouple wires 1, a first joint 2, a thermocouple probe 3, and a metal rod 4. The metal rod 4 is a cavity structure with a closed bottom end. The temperature measuring element 21 is implemented by a thermocouple probe 3. In one embodiment, each temperature measurement device 20 is configured with 6 thermocouple probes 3, and these 6 thermocouple probes 3 are respectively installed and fixed in the cavity of the metal rod 4. There are 6 holes in the metal rod 4, and the wires of each thermocouple probe 3 are in direct contact with the medium in the pipe through these holes, and the top of the metal rod 4 is sealed, so as to obtain the temperature change situation of the medium in the pipe. Among them, the metal rod 4 is made of a material with good rigidity. By doing so, not only can the measurement accuracy be improved and the time for measuring the temperature of the medium in the pipe be shortened, but also when CO2 leakage occurs in the pipeline, the metal rod 4 can be prevented from bending and affecting the collected temperature data results. Among them, for the thermocouple, it is a K-type thermocouple, the corresponding time is 100 ms, the measurement range is -200°C to 1300°C, and the measurement accuracy is ±1°C.

[0078] In one embodiment, as Figure 3 shown, further, two first grooves 9 are installed on the pipe wall 7. Among them, the two first grooves 9 are arranged oppositely and are respectively welded to the top and bottom of the pipe wall 7. The first joint 2 embeds and fixes the two ends of the temperature measuring structure 8 in the first grooves 9 fixed on the pipe wall 7, thereby fixing the temperature measuring structure 8.

[0079] The pressure sensor 6 is arranged on the pipe wall 7 at the corresponding position of the temperature measuring structure 8 to measure the pressure of the medium in the pipeline. Among them, the measuring range of the pressure sensor 6 is 0 to 16 MPa, the working temperature is -100 °C to 50 °C, and the measuring accuracy is 0.25% FS.

[0080] Further, a fixed second groove 15 is installed on the pipe wall 7. Among them, the second groove 15 is welded to the side wall of the pipeline interface at the corresponding position of the temperature measuring structure 8. The second joint 5 is used to embed the pressure sensor 6 into the second groove 15, thereby fixing the pressure sensor 6.

[0081] The data processing device 30 includes a plurality of acquisition boxes 11 and a computer terminal 10 to analyze and process the acquired temperature data and pressure data. Specifically, the data acquisition box 11 includes a main acquisition box and a slave acquisition box. In one embodiment, the computer terminal 10 is a computer, which is used to generate a distribution map of the two-dimensional temperature and phase state of the medium in the pipe according to the acquired data.

[0082] In addition, the data processing device 30 further includes: an embedded real-time controller 17, an Ethernet expansion chassis 19, a protection device, a power supply system, and an Ethernet cable 12. Specifically, the embedded real-time controller 17 is used to transmit the medium temperature and pressure data from each slave acquisition box to the main acquisition box in real time. The Ethernet expansion chassis 19 is arranged inside the second protection device 18. Each Ethernet expansion chassis 19 is used to transmit the real-time medium temperature data group and real-time medium pressure data collected by itself to the embedded real-time controller 17 of the next-level acquisition box 11 through the Ethernet expansion chassis 19 between the slave acquisition boxes. The protection device includes a first protection device 16 and a second protection device 18. It is arranged on the acquisition box 11 to protect the normal operation of the acquisition box 11. Among them, the first protection device 16 is arranged on the main acquisition box, and the second protection device 18 is arranged on the slave acquisition box. The power supply system is used to supply power to each device in the data processing device 30 to maintain the normal operation of the device. The Ethernet cable 12 is used to connect each acquisition box 11, as well as the connection between the main acquisition box and the computing terminal 10, and transmit the real-time acquired temperature data and pressure data.

[0083] In one embodiment, the system used by the data processing device 30 to collect and process temperature data and pressure data is the NI cRIO 9255 system. Among them, the data processing device 30 includes 1 computing terminal 10 and 5 data acquisition boxes 11. Among them, the computing terminal 10 is a computer, which is used to generate a distribution map of the two-dimensional temperature and phase state of the in-pipe medium corresponding to the collected data information. The multiple acquisition boxes 11 are composed of 1 main acquisition box and 4 slave acquisition boxes, and complete the measurement of the entire pipeline to be detected. Each acquisition box 11 is equipped with a number of acquisition cards, and each acquisition card is used to collect the in-pipe temperature data. Further, the main acquisition box includes: a protection device, a power supply device, and an NI cRIO 9255 embedded real-time controller. The real-time controller includes an industrial real-time processor with a first frequency, a DDR2 RAM with a first storage capacity, and a ROM with a second storage capacity. Among them, the first frequency is 800 MHz, the first storage capacity is 512 MB, and the second storage capacity is 4 GB. After the acquisition box 11 completes the acquisition of temperature data and pressure data, all the collected data is transmitted to the computing terminal 10 via the main acquisition box.

[0084] Additionally, the 4 slave acquisition boxes respectively include a protection device, a power supply, and an NI 9144 Ethernet expansion chassis.

[0085] Additionally, in one embodiment, the embodiments of the present invention include 16 IN acquisition cards, specifically 13 NI9219 and 3 NI9213, which are used to collect the in-pipe temperature data. In one embodiment, the software for collecting in-pipe data is written in LabVIEW.

[0086] Example 3

[0087] Based on the above-mentioned Embodiment 1 and Embodiment 2, the embodiments of the present invention also provide a method for measuring the temperature and phase state of the in-pipe medium (also referred to as the "in-pipe measurement method"). The in-pipe measurement method is applied to the leakage detection experiment of a specific medium pipeline. Among them, the specific medium pipeline is the leakage detection experiment of a carbon dioxide pipeline.

[0088] Figure 4 It is a schematic diagram of the steps of the method for measuring the temperature and phase state of the medium to be measured in the embodiments of the present application. As Figure 4 shown, the in-pipe measurement method can measure the temperature and phase state of the in-pipe medium according to this method, and carry out the leakage detection test of the pipeline according to the following step process:

[0089] Step S410: Set multiple groups of temperature measurement devices at different positions in the axial direction of the pipeline to be measured, and set corresponding pressure sensors on the side walls of different pipeline cross-sections. Each group of temperature measurement devices includes multiple temperature measurement elements uniformly arranged at different positions in the diameter direction of the corresponding pipeline cross-section.

[0090] Step S420: Use each temperature measurement element in each group of temperature measurement devices to measure the temperature of the medium inside the pipeline at the corresponding position.

[0091] Step S430: Use the pressure sensors on different pipeline cross-sections to measure the pressure of the medium inside the pipeline.

[0092] Step S440: Use the data processing device to collect in real time the medium temperature measured by each temperature measurement element and the medium pressure measured by the pressure sensor. Based on this, form the phase change and two-dimensional temperature distribution law of different media inside the pipeline.

[0093] In this way, the embodiment of the present invention can use the above method for measuring the temperature and phase state of the medium inside the pipeline to comprehensively display the change of the characteristics of the medium inside the pipeline when CO2 leaks inside the pipeline by measuring the two-dimensional temperature and phase state of the medium inside the pipeline.

[0094] Example 4

[0095] Based on the pipeline measurement method provided in the above Embodiment 3, the embodiment of the present invention also provides a specific embodiment of this method.

[0096] Figure 5 It is a schematic diagram of the steps for calibrating the devices before the leakage experiment of the method for measuring the temperature and phase state of the medium inside the pipeline to be measured in the embodiment of the present application. As Figure 5 shown, before starting the system to measure the temperature and phase state of the medium inside the pipeline, process each device in the system according to the following steps:

[0097] Step T1: Calibrate the thermocouple to be installed. First, insert the thermocouple into the ice-water mixture and connect the thermocouple to the data processing device. If the error between the data measured by the thermocouple and the actual value of the ice-water is within 0.5 °C, the measurement of this thermocouple is reliable and can be used in the following experiment.

[0098] Step T2: Open holes in the experimental pipeline at different positions along the axial direction of the pipeline at a certain distance, weld the first groove on the top and bottom of the pipeline, and then insert the temperature measurement device into the first groove through the first joint.

[0099] Step T3: Calibrate the pressure sensor to be installed. If the acquisition frequency of the pressure sensor is the same as that of the thermocouple and the measurement accuracy is 0.25% FS, it indicates that the pressure sensor meets the requirements of the following experiment.

[0100] Step T4: Weld a second groove on the side wall of the pipeline at the location where the temperature measuring device is located, and then embed the pressure sensor into the second groove through a second joint, thereby fixing the pressure sensor.

[0101] Step T5: Connect the wires of the temperature measuring device and the pressure sensor to the corresponding slave acquisition box.

[0102] Step T6: After installing the temperature measuring device and the pressure sensor as above, it is necessary to test whether the system meets the sealing requirements. First, conduct a water pressure test to check the pressure-bearing capacity of each joint of the temperature measuring device and the pressure sensor. In the water pressure test, the maximum pressure in the pressure-bearing container can reach 12 MPa and can be maintained for 30 minutes. During the water pressure test of the device, check whether there are any leakage points in the pipeline. If there are no leakage points, it indicates that the system meets the sealing requirements.

[0103] After detecting each device in the system by completing the above steps, then measure the temperature and phase change law of the medium in the pipeline according to the method described in Embodiment 3.

[0104] Example 5

[0105] Based on the pipeline measurement method provided in the above Embodiment 3, the embodiments of the present invention will obtain the distribution and change law of the temperature and phase state in the pipeline during the leakage process according to the following examples.

[0106] In the first example, during the high-pressure CO2 pipeline leakage experiment, according to the temperature data collected by each thermocouple and the pressure data collected by the pressure sensor corresponding to that cross-section, the temperature change law diagram of the vertical cross-section and the P-T diagram of the vertical cross-section can be obtained. And synchronously collecting the data collected by all the temperature measuring devices and all the pressure sensors in the pipeline can obtain the change law of the temperature and pressure of the medium in the pipeline during the leakage experiment.

[0107] Specifically, the critical temperature of CO2 is 31.1 °C and the critical pressure is 7.3 MPa. Then, in the P-T diagram, this point is the critical point of CO2. When the temperature and pressure data of the medium in the pipeline are both higher than the critical point, the phase state of the medium in the pipeline is the supercritical phase. When the measured temperature in the pipeline is lower than the critical temperature and the pressure is higher than the critical pressure, the phase state of the medium in the pipeline is the dense liquid phase (also called "dense phase").

[0108] Specifically, the triple point temperature of CO2 is -56.5 °C and 0.5 MPa. When the temperature and pressure of CO2 drop to this point, the CO2 gas becomes dry ice state and dry ice is generated in the pipeline.

[0109] Based on the temperature and pressure data of the medium inside the pipe, the phase state of CO2 can be obtained. By changing the phase state of CO2 inside the pipe, a two-dimensional variation law diagram of the temperature inside the pipe at different times and a two-dimensional variation law diagram of the phase state inside the pipe at different times are plotted to study the two-dimensional distribution of the temperature and phase state inside the pipe. Among them, there is a curve between the P-T critical point and the triple point, and this curve is the gas-liquid saturation line of CO2. On the left side of the gas-liquid saturation line, CO2 is in the liquid phase. On the right side of the gas-liquid saturation line, CO2 is in the gas phase. According to the measured P-T diagram, the different states of the medium inside the pipe can be intuitively felt, realizing simple, direct, and efficient measurement.

[0110] In the second example, first, according to Example 4, before starting the system to measure the temperature and phase state of the medium inside the pipe, the steps of processing each device in the system are used to install and calibrate the system to be measured. Among them, a plurality of calibrated thermocouples are evenly installed in a pipe with a first length (for example, the first length is 300 m) at a first same distance interval.

[0111] After starting the pipeline leakage experiment, the system collects and processes the temperature data and pressure data of the medium inside the pipe to form the two-dimensional phase state distribution law inside the pipe. Figure 6 This is a diagram of the two-dimensional variation and distribution law of the temperature of the medium inside the pipe at different times in an embodiment of the system for measuring the temperature and phase state of the medium inside the pipe to be measured according to the embodiment of the present application. Among them, H represents the height of the metal rod in the vertical direction inside the pipe, and L represents the distance from the bottom of the far end of the leakage port to the top of the leakage port. As Figure 6 shown, during the period from 40 s to 160 s, the temperature difference gradually appears on any vertical cross-section, showing a trend of gradually decreasing temperature from the top to the bottom of the cross-section; the two-dimensional distribution of the temperature is a trend of gradually decreasing temperature from the top of the leakage port to the bottom of the far end of the leakage.

[0112] Combined with the pressure data measured by the pressure sensors on the same side wall of the pipe, a diagram of the two-dimensional variation and distribution law of the temperature and phase state of the medium inside the pipe can be obtained. Figure 7 This is a diagram of the two-dimensional variation and distribution law of the temperature and phase state of the medium inside the pipe at different times in another embodiment of the system for measuring the temperature and phase state of the medium inside the pipe to be measured according to the embodiment of the present application. Among them, H represents the height of the metal rod in the vertical direction inside the pipe, and L represents the distance from the bottom of the far end of the leakage port to the top of the leakage port. As Figure 7As shown, at the 3s moment when the leakage starts, the phase state of CO2 in the pipe still remains the initial supercritical phase. At the 60s moment of the leakage, the gaseous CO2 is distributed at the top of the pipeline, and the closer to the leakage orifice, the greater the amount of the gaseous phase generated; the liquid phase is distributed at the bottom of the pipeline, and the closer to the far end of the leakage, the greater the amount of the liquid phase; the height of the interface between the gaseous and liquid phases gradually increases from the leakage orifice to the far end of the leakage. As the leakage continues to 80s, 100s, and 160s, the gaseous phase gradually increases, the liquid phase gradually decreases, and the interface between the gaseous and liquid phases gradually approaches the bottom at the far end of the leakage. Especially at 160s after the leakage starts, dry ice is generated at the bottom of the pipeline at the far end of the leakage, and a gas-liquid-solid three-phase appears in the pipe.

[0113] As described above, it is only the preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

[0114] In the description of the present invention, unless otherwise specified, "a plurality of" means two or more; the orientation or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0115] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0116] It should be understood that the embodiments disclosed by the present invention are not limited to the specific structures, processing steps, or materials disclosed herein, but should extend to equivalent alternatives of these features understood by those of ordinary skill in the relevant art. It should also be understood that the terms used herein are only for the purpose of describing specific embodiments and do not mean to limit.

[0117] As used herein, the phrase "an embodiment" or "embodiments" means that a particular feature, structure, or characteristic described in connection with the embodiments is included in at least one embodiment of the present invention. Thus, the appearances of the phrase "an embodiment" or "embodiments" throughout the specification are not necessarily all referring to the same embodiment.

[0118] The embodiments of the present invention are provided for purposes of illustration and description, and are not intended to be exhaustive or to limit the invention to the disclosed forms. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are chosen and described in order to best explain the principles of the invention and its practical application, and to enable those of ordinary skill in the art to understand the invention for the purpose of designing various embodiments with various modifications suitable for a particular use.

[0119] Although the embodiments disclosed herein are as described above, the above content is only an embodiment adopted for the convenience of understanding the present invention, and is not intended to limit the present invention. Any person skilled in the art within the technical field to which the present invention pertains may make any modifications and variations in the form and details of the implementation without departing from the spirit and scope disclosed by the present invention. However, the scope of patent protection of the present invention shall still be subject to the scope defined by the appended claims.

Claims

1. A system for measuring the temperature and phase state of a medium in a pipe, characterized in that, Comprising: Multiple groups of temperature measurement devices respectively arranged at different positions in the axial direction of the pipeline to be measured. Each group of temperature measurement devices has a plurality of temperature measurement elements evenly arranged at different positions in the diameter direction of the corresponding pipeline cross-section, and each temperature measurement element is used to measure the temperature of the medium inside the pipeline at the corresponding position; A pressure sensor, which is arranged on the side wall of the corresponding pipeline cross-section and is used to measure the pressure of the medium inside the pipeline; A data processing device, which is used to collect in real time the medium temperature measured by each temperature measurement element and the medium pressure measured by the pressure sensor, and based on this, form the phase change and two-dimensional temperature distribution law of different media inside the pipeline.

2. The system according to claim 1, wherein The temperature measurement device includes: A metal rod, which is installed on the inner wall of the pipeline along the diameter direction of the pipeline cross-section. The metal rod is constructed with a hollow cavity for installing the plurality of temperature measurement elements; A first joint, which is used to fix the two ends of the metal rod on the side wall of the pipeline respectively.

3. The system according to claim 2, wherein At least two relatively arranged first grooves are constructed on the side wall of the pipeline. The first grooves are used as installation positions for inlaying and fixing the two ends of the metal rod on the side wall of the pipeline through the first joint.

4. The system according to claim 2 or 3, characterized in that, A plurality of holes are constructed on the metal rod, so that the hollow cavity is communicated with the internal space of the pipeline. Among them, the temperature measurement element is realized by a thermocouple probe, and each thermocouple probe passes through the corresponding hole to contact the external space of the metal rod.

5. The system according to claim 4, wherein The signal transmission wire of each thermocouple probe is led out through the first end of the metal rod and connected to the data processing device.

6. The system according to any one of claims 1 to 5, characterized in that, The system further includes: A second joint, which is used to inlay the pressure sensor on the side wall of the pipeline; A second groove, which is constructed on the side wall of the pipeline and is used as an installation position for inlaying and fixing the pressure sensor on the side wall of the pipeline through the second joint.

7. The system according to any one of claims 1 to 6, characterized in that The data processing device includes: Multiple data acquisition boxes respectively corresponding to each group of temperature measurement devices. Each data acquisition box is connected in a cascaded manner. Each data acquisition box is used to collect the real-time medium temperature data groups at different pipeline heights of the corresponding group of temperature measurement devices at different measurement times, and collect the real-time medium pressure data of each pipeline cross-section; A calculation terminal, which is used to obtain the real-time medium temperature data groups and the real-time medium pressure data from different data acquisition boxes, generate phase diagrams of different pipeline cross-sections, and two-dimensional temperature change laws formed at different pipeline heights of different pipeline cross-sections. Based on this, identify the formation time and formation position of different phases of the medium inside the pipeline. The different phases include but are not limited to gas phase, liquid phase, solid phase, supercritical phase and dense liquid phase.

8. The system according to claim 7, characterized in that, The multiple data acquisition boxes are constructed as one main acquisition box and several slave acquisition boxes. Among them, the main acquisition box is directly connected to the calculation terminal, and the other acquisition boxes except the main acquisition box are slave acquisition boxes. Among them, The main acquisition box is equipped with a first protection device and an embedded real-time controller disposed inside the first protection device. The embedded real-time controller is configured to transmit the real-time medium temperature data groups, the real-time medium pressure data from each slave acquisition box, and the real-time medium temperature data groups and the real-time medium pressure data collected by itself to the computing terminal; Each slave acquisition box is equipped with a second protection device and an Ethernet expansion chassis disposed inside the second protection device. Each Ethernet expansion chassis is configured to transmit the real-time medium temperature data groups and the real-time medium pressure data collected by itself to the embedded real-time controller through a plurality of Ethernet expansion chassis inside the slave acquisition boxes connected between its own chassis and the embedded real-time controller.

9. The system according to claim 8, characterized in that, Each data acquisition box is connected to each other through an Ethernet cable, and the main acquisition box is connected to the computing terminal through an Ethernet cable.

10. The system according to any one of claims 1 to 9, characterized in that, The system is applied to a leakage detection experiment of a specific medium pipeline, wherein the specific medium pipeline is a carbon dioxide pipeline.

11. A method for measuring the temperature and phase state of a medium in a pipe, characterized in that, The method is implemented by using the system according to any one of claims 1 to 10, wherein the method includes: A plurality of temperature measurement devices are respectively arranged at different positions in the axial direction of the pipeline to be measured, and corresponding pressure sensors are arranged on the side walls of different pipeline cross-sections. Each group of temperature measurement devices includes a plurality of temperature measurement elements uniformly arranged at different positions in the diameter direction of the corresponding pipeline cross-section; Each temperature measurement element in each group of temperature measurement devices is used to measure the temperature of the medium inside the pipeline at the corresponding position; The pressure sensors on different pipeline cross-sections are used to measure the pressure of the medium inside the pipeline; The data processing device is used to collect in real time the medium temperature measured by each temperature measurement element and the medium pressure measured by the pressure sensor, and based on this, form the phase change and two-dimensional temperature distribution law of different media inside the pipeline.

12. The method according to claim 11, wherein The method is applied to a leakage detection experiment of a specific medium pipeline, wherein the specific medium pipeline is a carbon dioxide pipeline.

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