Gas-liquid two-phase fluid detection assembly and detection method thereof

Abstract

The invention relates to the technical field of detection, in particular to a gas-liquid two-phase fluid detection assembly and a detection method thereof.The gas-liquid two-phase fluid detection assembly comprises an outer pipe, an inner pipe and a capacitance sensor, the outer pipe is used for fluid circulation, the inner pipe is arranged on the outer pipe, the inner pipe is used as a plate of a capacitor, and the capacitance sensor is arranged on the inner pipe; the capacitive sensor is connected with the outer pipe and the inner pipe. The capacitance between the inner pipe and the outer pipe is measured through the capacitance sensor, the real-time change of the conductivity between the polar plates is calculated through the real-time change of the capacitance, the real-time mass ratio components of the gaseous state and the liquid state of the fluid between the polar plates can be calculated, and then the real-time mass ratio components of the gaseous state and the liquid state in the pipeline are calculated. The mass ratio components of gas and liquid can be monitored in real time, meanwhile, the online flow velocity of the gas and the online flow velocity of the liquid are measured respectively, the total mass flow is calculated, real-time data help a user optimize the production process, operation parameters are adjusted in time, and the uncertainty in production can be reduced.

Description

Technical Field

[0001] The present invention relates to the field of detection technology, and in particular to a gas-liquid two-phase fluid detection component and a detection method thereof. Background Art

[0002] Gas-liquid two-phase flow refers to the flow of substances in which both gas and liquid exist at the same time. Due to the interface effect and relative velocity between the two phases in gas-liquid two-phase flow, the interface is randomly variable in time and space, making its flow characteristics far more complex than single-phase flow, and its characteristic parameters are also more than single-phase flow. The flow rate and composition of gas-liquid two-phase flow are important parameters in gas-liquid two-phase flow, and their measurement is also called dual-parameter measurement of gas-liquid two-phase flow.

[0003] At present, when detecting the components of gas-liquid two-phase fluids, gas analyzers, liquid analyzers, phase separators and other equipment are generally used for sampling detection. These components can detect the composition and concentration of gas and liquid respectively. However, due to the difference between the flow rate of mixed gas and liquid, and the gas and liquid are mixed together, the flow rate cannot be measured by the Kepler effect of ultrasound, which makes it difficult to perform online real-time detection. Summary of the invention

[0004] The purpose of the present invention is to solve the problem in the prior art that there is a difference between the flow rate of mixed gas and liquid, and the flow rate cannot be measured by the Kepler effect of ultrasound, resulting in difficulty in online real-time detection. A gas-liquid two-phase fluid detection component is provided, which can monitor the mass ratio of gas and liquid components in real time, and also measure the online flow rates of gas and liquid respectively to calculate the total mass flow rate.

[0005] In order to achieve the above-mentioned purpose, the present invention provides a gas-liquid two-phase fluid detection component, including an outer tube, an inner tube and a capacitive sensor, wherein the outer tube is used for fluid circulation and serves as a plate of a capacitor, the inner tube is arranged on the outer tube, and the inner tube is used as another plate of the capacitor, the capacitive sensor is connected to the outer tube and the inner tube, and the capacitive sensor is used to detect the capacitance of the fluid in the outer tube.

[0006] As a further description of the above technical solution: a first speed sensor is arranged above the outer tube, and a second speed sensor is arranged below the outer tube.

[0007] As a further description of the above technical solution: the outer tube is coaxial with the inner tube.

[0008] As a further description of the above technical solution: the first speed sensor and the second speed sensor are located within the range of 1-3 pipe diameters on the rear side of the coaxial pipe, the first speed sensor is located at the vertical upper part of the outer pipe, and the second speed sensor is located at the vertical bottom of the outer pipe.

[0009] A gas-liquid two-phase fluid detection method, S1, online detection of the capacitance of the fluid in an outer tube by a capacitance sensor; S2, calculation of εr based on the capacitance detected by the capacitance sensor; S3, calculation of the percentage components of gas and liquid by εr; S4, detection of the flow velocities of the upper and lower parts of the fluid in the outer tube by a first speed sensor and a second speed sensor.

[0010] As a further description of the above technical solution: in S2, the capacitance determining formula is: C = εrS / 4πkd. In this formula, only εr changes, so εr can be calculated by measuring the capacitance C.

[0011] As a further description of the above technical solution: in S3, the dielectric constant εr of different substances is different. Assuming that the gaseous εr is A and the liquid εr is B, the current εr is calculated to be D by measuring the capacitance. The percentage components of the gaseous and liquid states can be calculated by the formula x%*A+(1-X%)*B=D.

[0012] As a further description of the above technical solution: in S4, the upper flow rate is the flow rate of the fluid containing a larger gaseous portion, and the lower flow rate is the flow rate of the fluid containing a larger liquid portion.

[0013] The above technical solution has the following advantages or beneficial effects:

[0014] 1. The present invention measures the capacitance between the outer tube and the inner tube through a capacitance sensor, and can calculate the gaseous and liquid components of the fluid between the outer tube and the inner tube, and calculate the flow rate and components in the system. The change in the conductivity of the medium in the pipeline is calculated through the change in capacitance, and the real-time mass ratio components of the gaseous and liquid states of the fluid between the plates are calculated, and then the real-time mass ratio components of the gaseous and liquid states in the pipeline are calculated. The mass ratio components of the gaseous and liquid states can be monitored in real time, and the online flow rates of the gaseous and liquid states are measured respectively to calculate the total mass flow rate.

[0015] 2. The present invention can simultaneously provide the mass ratio of gas and liquid, gas mass flow rate, and liquid mass flow rate. It can also calculate the gas volume flow rate, liquid volume flow rate, and total volume flow rate based on the input gas and liquid density parameters. Real-time data helps users optimize the production process, ensure product quality and process efficiency, and timely adjustment of operating parameters can reduce uncertainties in production. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of the structure of a gas-liquid two-phase fluid detection component in one embodiment of the present invention Figure 1 ;

[0017] Figure 2A schematic diagram of the structure of a gas-liquid two-phase fluid detection component in one embodiment of the present invention Figure 2 .

[0018] Legend:

[0019] 1. Outer tube; 2. Inner tube; 3. Capacitive sensor; 4. First speed sensor; 5. Second speed sensor. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] See also Figure 1 The present invention provides a technical solution: a gas-liquid two-phase fluid detection component of the present invention includes: an outer tube 1, an inner tube 2 and a capacitive sensor 3, the outer tube 1 is used for fluid circulation, the inner tube 2 is arranged on the outer tube 1, the inner tube 2 is used as a plate of a capacitor, the capacitive sensor 3 is connected to the outer tube 1 and the inner tube 2, and the capacitive sensor 3 is used to detect the capacitance of the fluid in the outer tube 1.

[0022] In this embodiment, the capacitance between the outer tube 1 and the inner tube 2 is measured by the capacitance sensor 3, and the gaseous and liquid components of the fluid between the outer tube 1 and the inner tube 2 can be calculated, and the flow rate and components in the system can be calculated. The change in the conductivity of the medium in the pipeline is calculated by the capacitance change, and the real-time mass ratio of the gaseous and liquid components of the fluid between the plates is calculated. Then, the real-time mass ratio of the gaseous and liquid components in the pipeline is calculated, and the mass ratio of the gaseous and liquid components is monitored in real time. At the same time, the online flow rates of the gaseous and liquid are measured respectively to calculate the total mass flow rate. Real-time data helps optimize the production process, ensure product quality and process efficiency, and timely adjustment of operating parameters can avoid production interruptions and waste.

[0023] Among them, the mass ratio of gas and liquid, gas mass flow rate, and liquid mass flow rate can be given at the same time; the gas volume flow rate, liquid volume flow rate, and total volume flow rate can also be calculated based on the input gas and liquid density parameters. Real-time data helps users optimize the production process, ensure product quality and process efficiency, and timely adjustment of operating parameters can reduce uncertainties in production.

[0024] Specifically, the capacitance sensor 3 can detect the capacitance of the fluid in the outer tube 1 because the measurement principle of capacitance involves the electric field between the two plates of the capacitor. The inner tube 2 serves as one plate of the capacitor, and the outer tube 1 serves as the plate of the other capacitor. The conductivity and dielectric constant of the fluid will affect the capacitance value between the two plates. The capacitance sensor 3 can reflect the properties and flow rate of the fluid by measuring the change in capacitance value, thereby detecting the capacitance of the fluid in the outer tube 1.

[0025] Among them, capacitance is also called "capacitance", which refers to the storage of free charge under a given potential difference, denoted by C, and the international unit is farad (F). Generally speaking, charges will move under force in an electric field. When there is a medium between conductors, the movement of charges is hindered and the charges accumulate on the conductors, resulting in the accumulation and storage of charges. The amount of stored charge is called capacitance. In two large planes, because the components change, the conductivity in the space also changes. The change in conductivity causes the capacitance between the two planes to change.

[0026] If a capacitor carries 1 Coulomb of charge and the potential difference between the two electrodes is 1 volt, the capacitance of this capacitor is 1 farad, that is: C = Q / U. However, the size of the capacitor is not determined by Q (charge) or U (voltage), that is, the determining formula for capacitance is: C = εrS / 4πkd. Among them, εr is the relative dielectric constant, S is the area of ​​the capacitor plates, d is the distance between the capacitor plates, and k is the electrostatic force constant. For a common parallel plate capacitor, the capacitance is C = εS / d (ε is the dielectric constant of the medium between the plates, ε = εrε0, ε0 = 1 / 4πk, S is the plate area, and d is the distance between the plates). C = εrS / 4πkd, in this formula, only εr changes, so εr can be calculated by measuring C.

[0027] The dielectric constant εr of different substances is different. Assuming that the gas εr is A and the liquid εr is B, the current εr is calculated to be C by measuring the capacitance. The percentage components of the gas and liquid can be calculated by the formula x%*A+(1-X%)*B=C.

[0028] like Figure 1 and Figure 2 As shown, a first speed sensor 4 is arranged above the outer tube 1, and a second speed sensor 5 is arranged below the outer tube 1; through the first speed sensor 4 and the second speed sensor 5, the online flow velocities of the gas and liquid can be measured respectively, the total volume flow rate can be calculated, and the ratio of the gas and liquid, the gas volume flow rate, and the liquid volume flow rate can be given at the same time.

[0029] like Figure 1As shown, the outer tube 1 is coaxial with the inner tube 2; the capacitance value of the capacitor depends on the medium between its two electrodes. The outer tube 1 and the inner tube 2 form a capacitor, in which the outer tube 1 acts as one electrode and the inner tube 2 acts as another electrode. The dielectric constant of the fluid affects the capacitance value. The coaxial design ensures that the electrodes of the capacitor maintain a stable distance, so that the capacitance measurement is more accurate and is not affected by changes in the pipeline structure. This configuration allows the capacitive sensor to accurately detect changes in the dielectric constant of the fluid, thereby reflecting the properties and state of the fluid (gas or liquid ratio). The coaxial structure reduces external interference and non-uniformity, ensuring that the capacitive sensor 3 can stably measure changes in the fluid capacitance, thereby providing more accurate gas-liquid two-phase fluid detection. The coaxial design helps to achieve stable capacitance measurement and accurately reflect the fluid state.

[0030] like Figure 1 and Figure 2 As shown, the first speed sensor 4 and the second speed sensor 5 are located within the range of 1-3 pipe diameters on the rear side of the coaxial pipe, the first speed sensor 4 is located at the vertical upper part of the outer pipe 1, and the second speed sensor 5 is located at the vertical bottom of the outer pipe 1.

[0031] In this embodiment, by arranging two velocity sensors at the upper and lower parts, the flow velocities of gas and liquid can be measured respectively, so as to more accurately analyze the flow characteristics of gas-liquid two-phase flow. The sensors are located within the range of 1-3 pipe diameters on the rear side of the coaxial pipe, which can ensure the stability of the flow field in the measurement area and reduce the measurement errors caused by the pipe shape and flow disturbances. The sensors are set in a vertical position, which reduces the influence of turbulence and disturbance in the flow on the velocity measurement results, thereby ensuring the accuracy and reliability of the measurement results.

[0032] A gas-liquid two-phase fluid detection method, S1, online detection of the capacitance of the fluid in the outer tube 1 by a capacitance sensor 3; S2, calculation of εr based on the capacitance detected by the capacitance sensor 3; S3, calculation of the percentage components of the gaseous and liquid states by εr; S4, detection of the flow velocities of the upper and lower parts of the fluid in the outer tube 1 by a first velocity sensor 4 and a second velocity sensor 5. In S2, the capacitance determination formula is: C = εrS / 4πkd, in this formula, only εr is variable, so εr can be calculated by measuring the capacitance C. In S3, the dielectric constant εr of different substances is different, assuming that the gaseous εr is A and the liquid εr is B, the current εr is calculated to be D by measuring the capacitance, and the percentage components of the gaseous and liquid states can be calculated by the formula x%*A+(1-X%*B=D. The upper flow velocity is the flow velocity of the fluid containing more gaseous parts, and the lower flow velocity is the flow velocity of the fluid containing more liquid parts.

[0033] In this embodiment, a capacitance sensor is used to measure the capacitance of the fluid, and the relative dielectric constant εr of the fluid is calculated by the measured capacitance value. The percentage of the gas state is calculated based on εr, and then the ratio of the gas state to the liquid state is obtained. A velocity sensor is used to measure the flow rate of the fluid in the upper and lower parts of the pipeline to obtain detailed information on the flow state. The capacitance sensor and the velocity sensor are measured online to monitor the fluid state and composition changes in real time. The capacitance measurement provides an accurate calculation of the gas-liquid ratio, and the flow rate detection further improves the understanding of the fluid flow conditions. It can be used for various different gas-liquid two-phase fluid systems and has high flexibility and adaptability.

[0034] Among them, the mass percentage of gas and liquid is obtained through the change of capacitance between the outer tube 1 and the inner tube 2, and the mass flow rate of gas and liquid is measured. By inputting the density of gas and liquid, the volume percentage can be calculated.

[0035] Specifically, if the potential difference between the two electrodes of a capacitor is 1 volt when it carries 1 cubic meter of charge, the capacitance of this capacitor is 1 farad, that is: C = Q / U. However, the size of the capacitor is not determined by Q (charge) or U (voltage), that is, the capacitance determination formula is: C = εrS / 4πkd. Among them, εr is the relative dielectric constant, S is the area of ​​the capacitor plates, d is the distance between the capacitor plates, and k is the electrostatic force constant. For a common parallel plate capacitor, the capacitance is C = εS / d (ε is the dielectric constant of the medium between the plates, ε = εrε0, ε0 = 1 / 4πk, S is the plate area, and d is the distance between the plates). C = εrS / 4πkd, in this formula, only εr changes, so εr can be calculated by measuring C.

[0036] The dielectric constant εr of different substances is different. Assuming that the gaseous εr is A and the liquid εr is B, the current εr is calculated to be C by measuring the capacitance. The percentage component of the gaseous state can be calculated by the formula x%*A+(1-X%)*B=C.

[0037] Working principle: By measuring the capacitance between the outer tube 1 and the inner tube 2 through the capacitance sensor 3, the gaseous and liquid components of the fluid between the outer tube 1 and the inner tube 2 can be calculated, and the flow rate and components in the system can be calculated. The change in the conductivity of the medium in the pipeline is calculated through the change in capacitance, and the real-time mass ratio of the gaseous and liquid components of the fluid between the plates is calculated, and then the real-time mass ratio of the gaseous and liquid components in the pipeline is calculated. The mass ratio of the gaseous and liquid components is monitored in real time, and the online flow rate of the gaseous and liquid components is measured separately to calculate the total mass flow rate. Real-time data helps optimize the production process and ensure product quality and process efficiency. Timely adjustment of operating parameters can avoid production interruptions and waste.

[0038] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0039] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A gas-liquid two-phase fluid detection component, characterized in that: include: An outer tube (1), the outer tube (1) is used for fluid circulation and serves as a plate of a capacitor; an inner tube (2), the inner tube (2) being arranged on the outer tube (1), the inner tube (2) being used as another electrode plate of the capacitor; A capacitance sensor (3), the capacitance sensor (3) being connected to the outer tube (1) and the inner tube (2), the capacitance sensor (3) being used to detect the capacitance of the fluid in the outer tube (1).

2. A gas-liquid two-phase fluid detection component according to claim 1, characterized in that: A first speed sensor (4) is arranged above the outer tube (1), and a second speed sensor (5) is arranged below the outer tube (1).

3. A gas-liquid two-phase fluid detection component according to claim 1, characterized in that: The outer tube (1) and the inner tube (2) are coaxial.

4. A gas-liquid two-phase fluid detection component according to claim 2, characterized in that: The first speed sensor (4) and the second speed sensor (5) are located within a range of 1 to 3 pipe diameters on the rear side of the coaxial pipe, the first speed sensor (4) is located at the vertical upper part of the outer pipe (1), and the second speed sensor (5) is located at the vertical bottom part of the outer pipe (1).

5. A gas-liquid two-phase fluid detection method, characterized in that: S1, online detection of the capacitance of the fluid in the outer tube (1) by means of a capacitance sensor (3); S2, calculating εr according to the capacitance detected by the capacitance sensor (3); S3, calculate the percentage components of gas and liquid through εr; S4. Detect the flow velocities of the upper and lower parts of the fluid in the outer tube (1) by means of the first velocity sensor (4) and the second velocity sensor (5).

6. A gas-liquid two-phase fluid detection method according to claim 5, characterized in that: In S2, the capacitance is determined by: C = εrS / 4πkd. In this formula, only εr changes, so εr can be calculated by measuring the capacitance C.

7. A gas-liquid two-phase fluid detection method according to claim 6, characterized in that: In S3, the dielectric constant εr of different substances is different. Assuming that the gas εr is A and the liquid εr is B, the current εr is calculated to be D by measuring the capacitance. The percentage components of gas and liquid can be calculated by the formula x%*A+(1-X%)*B=D.

8. A gas-liquid two-phase fluid detection method according to claim 5, characterized in that: In S4, the upper flow rate is the flow rate of the fluid containing more gaseous part, and the lower flow rate is the flow rate of the fluid containing more liquid part.

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