Device for measuring gas content in boiler tube

Abstract

The invention discloses a device for measuring the gas content in a boiler pipe, and the device comprises a detection pipe section which is connected in series with a to-be-detected pipeline and extends along a first direction; the base extends in the second direction and is connected with the detection pipe section, and the second direction is perpendicular to the first direction; the conducting probe assembly is installed on the base and comprises a plurality of probe sets, the probe sets extend in the first direction, and the detection ends of the probe sets extend into the detection pipe section so as to measure the gas content of fluid in the detection pipe section; and the data acquisition assembly is electrically connected with the plurality of probe groups. According to the device for measuring the gas content in the boiler pipe, the heat transfer condition of fluid in the boiler pipe can be stably and reliably monitored, early warning is achieved, when the device predicts that heat transfer deterioration of the boiler is about to happen, the boiler can adjust the operation state in time, and the boiler is protected. Therefore, the probability of pipe explosion and leakage accidents of the boiler is well reduced in the operation process of the boiler, and the boiler operates more stably and reliably.

Description

Technical Field

[0001] The invention relates to the technical field of boilers, in particular to a device for measuring the gas content in a boiler tube. Background Art

[0002] During operation, the water-cooled wall tubes of thermal power plant boilers are prone to heat transfer degradation due to the complex flow and heat transfer characteristics of the working fluid (water-steam two-phase flow) under high temperature and high pressure. When the fluid dryness within the tubes is too high or the gas-liquid phase is unevenly distributed, a steam film forms near the tube walls, causing a sudden drop in the heat transfer coefficient and a sharp increase in tube wall temperature. This can lead to problems such as overheating, creep, and oxidation, resulting in tube bursts and leaks.

[0003] In related technologies, traditional thermal power units mainly adjust their operations through changes in tube wall temperature. This method has a certain lag because an increase in tube wall temperature means that heat transfer has deteriorated. At this time, it is too late to make operational adjustments and early warnings cannot be provided, thereby increasing the probability of boiler tube burst and leakage accidents. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a device for measuring the gas content within boiler tubes. By detecting the gas content in the fluid, the device can determine the fluid dryness, thereby enabling real-time monitoring of heat transfer within the boiler tubes. This provides early warning of heat transfer deterioration, thereby reducing the probability of boiler tube bursts and leaks.

[0005] According to the present invention, the device for measuring the gas content in a boiler tube includes: a detection tube section, the detection tube section being serially connected to the pipeline to be detected, the detection tube section extending along a first direction; a base, the base extending along a second direction and connected to the detection tube section, the second direction being perpendicular to the first direction; a conductivity probe assembly, the conductivity probe assembly being mounted on the base, the conductivity probe assembly including a plurality of probe groups, the probe groups extending along the first direction, the detection ends of the probe groups extending into the detection tube section to measure the gas content of the fluid in the detection tube section; and a data acquisition assembly, the data acquisition assembly being electrically connected to the plurality of probe groups.

[0006] According to the device for measuring the gas content in a boiler tube of the present invention, a detection tube section and a conductivity probe assembly are provided. The detection tube section is connected in series to the pipeline to be detected. The conductivity probe assembly is provided with multiple probe groups. The detection ends of the probe groups extend into the detection tube section to measure the gas content, and then the dryness of the fluid is obtained through the gas content. This allows the device to stably and reliably monitor the heat transfer of the fluid in the boiler tube, achieving early warning, so that the boiler can adjust its operating state in a timely manner when the device detects that the heat transfer is about to deteriorate. Therefore, the probability of a tube burst and leakage accident in the boiler can be greatly reduced during the operation of the boiler, making the boiler operation more stable and reliable.

[0007] In some embodiments of the present invention, the probe group includes: a first probe and a second probe, wherein one end of the first probe extends into the detection tube segment to form a first end, and one end of the second probe extends into the detection tube segment to form a second end, the first end and the second end constitute the detection end, and the first end and the second end are staggered in the first direction.

[0008] In some embodiments of the present invention, the conductivity probe assembly further includes: a probe barrel, the probe barrel being provided with a plurality of tube portions, the tube portions extending along the first direction and forming a probe outlet, the plurality of tube portions being arranged at intervals in the second direction, the plurality of probe groups being arranged in one-to-one correspondence with the plurality of tube portions, the probe groups extending out of the probe outlet along the first direction; and a first sealing member being provided in the tube portion, the first sealing member being sealingly connected between the probe group and the inner wall of the tube portion.

[0009] In one embodiment of the present invention, the base includes: a base body, the base body is connected to the detection tube section, the base body is provided with a first through-hole, the first through-hole extends along the second direction, the first through-hole passes through the base body and is connected to the detection tube section, and the probe barrel is passed through the first through-hole; a base cover, the base cover is provided on the side of the base body away from the detection tube section in the second direction, the base cover is fastened to the base body, the base cover is provided with a second through-hole, the second through-hole passes through the base cover along the second direction, and the probe barrel is passed through the second through-hole.

[0010] In some examples of the present invention, the device for measuring the gas content in the boiler tube also includes a fixing part, which is mounted on the probe cylinder and located between the base cover and the base body, wherein the fixing part is an elastic part, and the fixing part is configured to deform under the pressure of the base cover and the base body and clamp the probe cylinder to fix the conductivity probe assembly.

[0011] In one example of the present invention, in the second direction, a first mating groove is provided at one end of the base body facing the base cover, and the first mating groove extends in a ring shape along the circumference of the first through-hole, and a second mating groove is provided at one end of the base cover facing the base body, and the second mating groove extends in a ring shape along the circumference of the second through-hole, and the second mating groove cooperates with the first mating groove to define a fixed cavity, and the fixing part is arranged in the fixed cavity.

[0012] In one embodiment of the present invention, the probe barrel body also includes a main barrel portion, which extends along the second direction, and multiple tube portions are connected to the main barrel portion. The two ends of the detection tube segment in the first direction are respectively a first connecting end and a second connecting end, and the detection ends of multiple probe groups all extend along the first direction toward the first connecting end, wherein the minimum spacing between the detection end of the probe group and the end face of the first connecting end in the first direction forms a first spacing, and the spacing between the end face of the main barrel portion and the end face of the second connecting end in the first direction forms a second spacing, the ratio of the first spacing to the inner diameter of the detection tube segment is greater than 9, and the ratio of the second spacing to the inner diameter of the detection tube segment is greater than 4.

[0013] In some embodiments of the present invention, the plurality of probe groups include a first probe group, a second probe group and a third probe group, and the first probe group, the second probe group and the third probe group are arranged in sequence in the second direction, and in the first direction, the detection ends of the first probe group, the second probe group and the third probe group are staggered in sequence along the first direction.

[0014] In some embodiments of the present invention, the detection pipe section is detachably connected to the pipeline to be detected, or the detection pipe section is fixedly connected to the pipeline to be detected.

[0015] In some embodiments of the present invention, the data acquisition assembly includes: a data acquisition card and a wire, the data acquisition card is connected to the conductivity probe assembly through the wire; and an acquisition system, the acquisition system is communicatively connected to the data acquisition card.

[0016] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of a device for measuring the gas content in a boiler tube and a pipeline to be tested according to an embodiment of the present invention;

[0018] Figure 2 is a schematic diagram of a conductivity probe assembly according to an embodiment of the present invention;

[0019] Figure 3 yes Figure 2 A schematic diagram of a local enlargement of the point A shown in FIG;

[0020] Figure 4 is a schematic diagram of the detection ends of multiple probe groups in a conductivity probe assembly according to an embodiment of the present invention;

[0021] Figure 5 is a schematic diagram of the measurement principle of a conductivity probe assembly according to an embodiment of the present invention;

[0022] Figure 6 is a schematic diagram of an amplifying circuit in a data acquisition component according to an embodiment of the present invention;

[0023] Figure 7 is a waveform diagram of voltage data obtained by the conductivity probe assembly according to an embodiment of the present invention before binarization processing;

[0024] Figure 8 is a waveform diagram of voltage data obtained by the conductivity probe assembly according to an embodiment of the present invention after binarization processing;

[0025] Figure 9 is a schematic diagram of a conductivity probe assembly performing a calibration experiment according to an embodiment of the present invention;

[0026] Figure 10 The present invention is a flow chart of a device for measuring the gas content in a boiler tube and processing a signal.

[0027] Reference numerals:

[0028] 10. Detect pipe section;

[0029] 20. Base; 201. Weight reduction slot;

[0030] 21. Base body; 211. First matching groove; 22. Base cover; 221. Second matching groove;

[0031] 30. Conductivity probe assembly; 301. First probe group; 302. Second probe group; 303. Third probe group;

[0032] 31. Probe group; 311. First probe; 3111. First end; 312. Second probe; 3121. Second end;

[0033] 32. Probe cylinder; 321. Main cylinder; 322. Tube;

[0034] 33. First sealing member; 34. Second sealing member;

[0035] 40. Fixing parts;

[0036] 50. Data acquisition component;

[0037] 51. Data acquisition card; 52. Acquisition system;

[0038] 100. Device for measuring the gas content in boiler tubes; 200. Pipelines to be tested. DETAILED DESCRIPTION

[0039] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0040] Reference below Figures 1-10 The following describes an apparatus 100 for measuring the air void fraction in a boiler tube according to an embodiment of the present invention.

[0041] like Figures 1-10 As shown, the device 100 for measuring the gas content in a boiler tube according to an embodiment of the present invention is arranged in a pipeline 200 to be tested in a boiler. The device 100 for measuring the gas content in a boiler tube includes: a detection tube section 10, a base 20, a conductivity probe assembly 30 and a data acquisition assembly 50.

[0042] Specifically, the detection pipe section 10 is connected in series to the pipeline 200 to be detected, and the detection pipe section 10 is connected in series to the pipeline 200 along the first direction (eg Figure 1 The base 20 extends along the second direction (as shown in the front and rear directions); Figure 1 The conductive probe assembly 30 is mounted on the base 20 and includes a plurality of probe groups 31. The probe groups 31 extend along the first direction, and the detection ends of the probe groups 31 extend into the detection pipe section 10 to measure the gas content of the fluid in the detection pipe section 10. The data acquisition assembly 50 is electrically connected to the plurality of probe groups 31.

[0043] In this embodiment, the device 100 for measuring the gas content in the boiler tube is provided with a detection pipe section 10, which is connected in series in the pipeline 200 to be detected. For example, the pipeline 200 to be detected can be a water-cooled wall tube of the boiler, and the detection pipe section 10 can be an additional pipe section structure. Part of the pipe section of the water-cooled wall tube can also be used as the detection pipe section 10. The form of the detection pipe section 10 can be flexibly set according to needs.

[0044] The detection tube segment 10 extends along a first direction, so the fluid in the detection tube segment 10 flows along the first direction. The base 20 extends along a second direction and is connected to the detection tube segment 10. The conductivity probe assembly 30 is mounted on the base 20. The simple structure facilitates the installation and arrangement of the conductivity probe. The second direction is perpendicular to the first direction, which can more conveniently meet detection requirements. After the conductivity probe assembly 30 is assembled and fixed to the detection tube segment 10 through the base 20, the detection end of the conductivity probe assembly 30 can be directly facing the flow direction of the fluid in the detection tube segment 10 for detection.

[0045] In this embodiment, the conductivity probe assembly 30 includes a plurality of probe groups 31. The probe groups 31 extend along a first direction and extend into the detection tube section 10. The probe groups 31 detect the gas content of the fluid in the detection tube section 10. The fluid here may refer to the water-steam two-phase flow in the boiler tube. Since the dryness and gas content can be converted, the dryness of the fluid is an important criterion for characterizing the heat transfer conditions in the boiler tube. Therefore, in this embodiment, the gas content of the fluid in the detection tube section 10 is measured by the probe group 31 to obtain the dryness of the fluid, thereby enabling real-time monitoring of the heat transfer conditions in the boiler tube. Further, the heat exchange conditions in the tube can be monitored in a timely manner, achieving early warning, and allowing the boiler to adjust its operating state in a timely manner before the tube wall overheats, thereby significantly reducing the probability of a tube burst and leakage accident in the boiler.

[0046] In this embodiment, the conductivity probe assembly 30 is provided with multiple probe groups 31, which allows the conductivity probe assembly 30 to more stably and reliably detect and monitor gas void fraction during operation. If one or some of the multiple probe groups 31 are damaged and unable to detect, the conductivity probe assembly 30 can still use the remaining probe groups 31 for detection, thereby reducing the risk of single-point failure. This improves the operational stability and reliability of the device 100 for measuring gas void fraction in boiler tubes during long-term use, and effectively ensures the continuity of fluid detection by the device 100 for measuring gas void fraction in boiler tubes. In this embodiment, the probe groups 31 extend along a first direction, which meets the layout requirements for measuring gas void fraction in the fluid. This allows the detection ends of the probe groups 31 to face the incoming flow direction of the fluid in the detection pipe section 10, thereby ensuring stable fluid measurement.

[0047] In this embodiment, the device 100 for measuring the gas content in the boiler tube is provided with a data acquisition component 50, which is electrically connected to the plurality of probe groups 31. The data acquisition component 50 can process the fluid data collected by the probe groups 31 to obtain the dryness of the fluid and other fluid parameters, thereby meeting the fluid detection needs of the device 100 for measuring the gas content in the boiler tube.

[0048] According to an embodiment of the present invention, a device 100 for measuring the gas content in a boiler tube is provided with a detection tube section 10 and a conductivity probe assembly 30. The detection tube section 10 is connected in series to the pipeline 200 to be inspected. The conductivity probe assembly 30 is provided with multiple probe groups 31. The detection ends of the probe groups 31 extend into the detection tube section 10 to measure the gas content, and then the dryness of the fluid is obtained through the gas content. Therefore, the device 100 for measuring the gas content in a boiler tube can stably and reliably monitor the heat transfer of the fluid in the boiler tube, and realize early warning. When the device 100 for measuring the gas content in a boiler tube detects that the heat transfer of the boiler is about to deteriorate, the boiler can adjust its operating state in a timely manner, thereby greatly reducing the probability of a tube burst and leakage accident in the boiler during operation, and making the boiler operation more stable and reliable.

[0049] In some embodiments of the present invention, Figure 2 As shown, the probe group 31 may include: a first probe 311 and a second probe 312, wherein one end of the first probe 311 extends into the detection tube segment 10 to form a first end 3111, and one end of the second probe 312 extends into the detection tube segment 10 to form a second end 3121, the first end 3111 and the second end 3121 constitute a detection end, and the first end 3111 and the second end 3121 are staggered in the first direction.

[0050] In this embodiment, the probe group 31 includes a first probe 311 and a second probe 312. The first end 3111 of the first probe 311 and the second end 3121 of the second probe 312 constitute the detection end of the probe group 31. For example, the first end 3111 of the first probe 311 and the second end 3121 of the second probe 312 can be located on the same side of the probe group 31 in the first direction. The first end 3111 and the second end 3121 can be needle tip structures to meet the needs of detection. The first end 3111 and the second end 3121 are staggered in the first direction. Figure 2 and Figure 4 As shown, in the first direction, the needle tip at the first end 3111 and the needle tip at the second end 3121 may have a certain distance to meet measurement requirements.

[0051] When the conductivity probe assembly 30 cooperates with the data acquisition assembly 50 to measure gas void fraction, the conductivity probe assembly 30 can cooperate with the data acquisition assembly 50 to measure two-phase flow parameters such as bubble velocity, bubble chord length, and local average gas void fraction. It should be noted that the gas void fraction mentioned in this embodiment refers to the local gas void fraction. The local gas void fraction refers to the ratio of the gas volume to the total volume at a specific point or cross-section of the pipeline or channel through which the fluid passes, reflecting the distribution of bubbles or gas at that location. In this embodiment, when using the conductivity probe assembly 30 for measurement, the local gas void fraction at the detection end of the detection tube section 10 can be measured.

[0052] refer to Figure 5 As shown, Figure 5 This is a schematic diagram illustrating the measurement principle of the conductivity probe assembly 30. Taking the first probe 311 as an example, the resistance of resistor R1 in the figure is much greater than the resistance of the water in the fluid, Rx. When the first end 3111 contacts the water in the fluid, the measurement circuit is turned on, generating a voltage across resistor R1, and the voltmeter registers a high level. However, when the first end 3111 contacts the gas in the fluid, the measurement circuit is turned off, and the voltage across resistor R1 is zero. Therefore, a sharp drop and a sharp rise in the voltage at resistor R1 represent the first probe 311 entering and leaving the bubble, respectively. Thus, the moment the first probe 311 enters and exits the bubble can be determined based on the change in the voltage signal. Since the gas in the fluid is contained within the bubble, the bubble moves with the flow of the fluid. In this embodiment, the detection tube segment 10 extends in the first direction, and the bubble flows in the first direction.

[0053] The local gas content of the fluid at the detection end of the probe group 31 can be calculated by the following formula: In the formula is the local average gas content; T is the total acquisition time of the probe group 31; N is the total number of bubbles that appear during the acquisition process; i is the bubble number; (t0l-t0g)i is the time the first probe passes through the i-th bubble, and (t1l-t1g)i is the time the second probe passes through the i-th bubble.

[0054] The dryness of the fluid can be calculated using the following formula: Where x represents the dryness, It is expressed as the local average gas content, that is, the gas content to be measured by the device 100 for measuring the gas content in the boiler tube of this embodiment, ρ g It is expressed as the gas phase density, S is expressed as the slip ratio, that is, the ratio of the gas phase velocity to the liquid phase velocity. The slip ratio is generally determined by experiments or empirical formulas.

[0055] In this embodiment, the probe group 31 is provided with a first probe 311 and a second probe 312, so that the two measured local average gas content can be closer to the actual gas content of the fluid in the detection pipe section 10 after averaging processing, thereby improving the measurement accuracy and measurement precision.

[0056] The conductivity probe assembly 30 of this embodiment can also be used in conjunction with the data acquisition assembly 50 to measure bubble velocity and bubble chord length, thereby facilitating verification of the measurement accuracy of the apparatus 100 for measuring gas content in boiler tubes of this embodiment and obtaining more comprehensive fluid flow information. Because the first end 3111 and the second end 3121 are staggered in the first direction, the first end 3111 and the second end 3121 have different times of entering and exiting the bubble. For example, if the first end 3111 of the first probe 311 enters the bubble first, the bubble velocity can be calculated using the following formula: Where v represents the bubble velocity, ΔL represents the distance in the first direction between the tip of the first end 3111 of the first probe 311 and the tip of the second end 3121 of the second probe 312, t0g is the corresponding moment when the tip of the first end 3111 of the first probe 311 contacts the bubble during the process of the first probe 311 penetrating the bubble; t1g is the corresponding moment when the tip of the second end 3121 of the second probe 312 contacts the bubble during the process of the second probe 312 penetrating the bubble; t0l is the corresponding moment when the tip of the first end 3111 of the first probe 311 leaves the bubble when the first probe 311 passes through the bubble; t1l is the corresponding moment when the tip of the second end 3121 of the second probe 312 passes through the bubble. Since bubbles usually deform significantly after contacting the probe, previous studies often make the following assumptions: (1) During the process of the probe passing through the bubble, the outer surface of the bubble is a continuous curved surface and does not deform, so as to ignore the change in interface curvature caused by the probe; (2) It is assumed that the velocity vector of the bubble remains unchanged before and after passing through the probe.

[0057] The bubble chord length can be calculated using the following formula: Where L is the bubble chord length, and t is the total time it takes for the bubble to pass through the probe tip.

[0058] When the device 100 for measuring the gas content in the boiler tube is subjected to a calibration experiment, the principle of the calibration experiment is as follows: a high-speed camera method is used. Specifically, reference is made to Figure 9 As shown in the figure, C represents a high-speed camera, D represents a high-speed camera system, and E is a lighting board. During the shooting process of the high-speed camera, the position of the bubble at any time and the contact between the bubble and the probe tip in the probe group 31 can be observed. Using a ruler as an aid, the high-speed camera is used to obtain the time for the bubble to enter and leave a certain known length. The ratio of the known length to the time is the bubble velocity, and the bubble chord length is obtained by multiplying the velocity by the time the bubble passes through the probe.

[0059] By taking the two-phase flow parameters obtained by the high-speed camera method as the true values ​​and comparing them with the bubble velocity and bubble chord length measured by the conductivity probe assembly 30 in conjunction with the data acquisition assembly 50, the measurement errors of the device 100 for measuring the gas content in the boiler tube in this embodiment when measuring the bubble velocity and bubble chord length can be obtained, thereby verifying the accuracy of the probe measurement.

[0060] In some embodiments of the present invention, Figure 2 As shown, the conductivity probe assembly 30 further includes: a probe barrel 32 and a first sealing member 33. The probe barrel 32 is provided with a plurality of tube portions 322. The tube portions 322 extend along a first direction and form a probe outlet. The plurality of tube portions 322 are spaced apart in a second direction. The plurality of probe groups 31 are arranged in a one-to-one correspondence with the plurality of tube portions 322. The probe groups 31 extend out of the probe outlet along the first direction. The first sealing member 33 is provided in the tube portion 322. The first sealing member 33 is sealed between the probe group 31 and the inner wall of the tube portion 322.

[0061] In this embodiment, the probe cylinder 32 is provided with multiple tube portions 322, which extend along the first direction and form a probe outlet. The multiple probe groups 31 are arranged in a one-to-one correspondence with the multiple tube portions 322, and the probe group 31 extends out of the probe outlet along the first direction. The structure is simple and can well meet the needs of the probe group 31 to measure the fluid, so that the first probe 311 and the second probe 312 of the probe group 31 can extend along the first direction, that is, consistent with the flow direction of the fluid, so that the first probe 311 and the second probe 312 can cooperate to stably measure two-phase flow parameters such as bubble velocity, bubble chord length and gas content in the fluid.

[0062] The tube portion 322 is formed with a probe outlet, which facilitates the first and second probes 311, 312 to extend out of the probe barrel 32 and into the fluid within the detection tube section 10, thereby meeting the measurement requirements of the conductivity probe assembly 30. In this embodiment, a first seal 33 is provided in the tube portion 322 to seal between the probe assembly 31 and the inner wall of the tube portion 322. Specifically, the first seal 33 can seal between the first probe 311 and the inner wall of the tube portion 322, between the second probe 312 and the inner wall of the tube portion 322, and between the first probe 311 and the second probe 312. This effectively seals the probe assembly 31 at the probe outlet of the tube portion 322 and allows the probe assembly 31 to be more stably assembled and fixed to the probe barrel 32 via the first seal 33.

[0063] Further, refer to Figure 2 and Figure 3As shown, the outer surfaces of the first probe 311 and the second probe 312 in the probe group 31 can be provided with a high-temperature resistant and corrosion-resistant coating, and the second seal 34 can be filled between the first probe 311 and the first seal 33 and between the second probe 312 and the first seal 33, wherein the first end 3111 of the first probe 311 and the second end 3121 of the second probe 312 are not provided with a high-temperature resistant and corrosion-resistant coating.

[0064] In this embodiment, a second seal 34 is filled between the first probe 311 and the first seal 33, and a second seal 34 is filled between the second probe 312 and the first seal 33. For example, the second seal 34 can be a high-temperature and corrosion-resistant sealant, such as a high-temperature and corrosion-resistant silicone sealant, so as to further improve the sealing performance of the probe barrel 32 and the probe group 31 at the probe outlet, thereby better preventing liquid from entering the probe barrel 32 and interfering with the measurement operation of the conductivity probe assembly 30, so that the device 100 for measuring the gas content in the boiler tube is more stable and reliable during measurement.

[0065] In this embodiment, the first end 3111 of the first probe 311 and the second end 3121 of the second probe 312 are not provided with a high-temperature resistant and corrosion-resistant coating, that is, the detection end of the probe group 31 is not provided with a high-temperature resistant and corrosion-resistant coating, that is, the needle tips of the probes are all exposed, so that the first probe 311 and the second probe 312 can contact the water and bubbles in the fluid, thereby meeting the measurement needs.

[0066] like Figure 6 As shown, Figure 6 The schematic diagram of the amplifier circuit in the data acquisition component 50 is shown in FIG. B, which represents an operational amplifier. Specifically, the amplifier circuit uses a 3V button battery to power the entire circuit board. The voltage divider resistor R3 has a resistance of 5MΩ. Taking the first probe 311 in the probe group 31 as an example, the first probe 311 is connected to the negative pole of the power supply and grounded, and the probe barrel 32 is connected to the positive pole of the power supply to prevent the needle tip of the probe group 31 from being oxidized during the measurement process. Figure 6 In the figure, the first probe 311 should be connected to port 2 of interface O1, and the probe barrel 32 is connected to port 1 of interface O1. Based on the principle of the reverse operational amplifier circuit, a low-energy, low-noise operational amplifier LM358 is used to amplify the voltage on the voltage divider resistor R3. The operational amplifier can be powered by two 18650 lithium batteries with a voltage of 3.5V. The output voltage of the amplifier circuit is determined by the ratio of R2 and R4. In this embodiment, the resistance value of resistor R2 in the amplifier circuit is 1MΩ, and the resistance value of resistor R4 is 10MΩ, as shown in the following formula: Where Vout is the output voltage after amplification, V inIt is represented as the original voltage, that is, the voltage measured in the measurement circuit when the first probe 311 measures. It can be seen from this that the theoretical amplification factor of this circuit is 10 times, and the voltage change is sufficient to distinguish between the gas and liquid phases.

[0067] In this embodiment, the specific models and resistance values ​​of the power supply, operational amplifier B, voltage divider resistor R3, resistor R2, and resistor R4 can be flexibly adjusted according to actual needs and are not specifically limited here.

[0068] Further, refer to Figure 10 As shown, the electrical signal of the output voltage needs to be processed. Specifically, the data processing process includes steps such as preprocessing, signal binarization, rising edge and falling edge judgment, effective bubble discrimination and two-phase flow parameter calculation.

[0069] The preprocessing process is to first perform Fourier transform on the original signal, which is the voltage signal of the amplified output voltage, to obtain the frequency range of the noise in the original signal, and then call the median filter (medfiltl) in the Matlab function library to filter the voltage signal.

[0070] After filtering out the signal noise, it is necessary to obtain the time nodes when the bubble contacts and leaves the probe. When the probe passes through the bubble, due to the existence of surface tension, it takes a period of reaction time for the probe to penetrate and leave the bubble surface. Therefore, the voltage signal obtained is mostly not a regular rectangular wave but an approximate trapezoidal wave. Therefore, it is necessary to first convert the voltage signal during probe measurement into a binary rectangular wave signal before processing.

[0071] The binarization process uses a double threshold method, first with the threshold V max As a benchmark, it is considered that data greater than this threshold are all liquid phase signals. When the probe begins to contact and pass through the bubble, the voltage value changes from large to small, and the voltage drops to V max The corresponding time point is the starting time point t when the probe contacts the bubble in , at this time, will be greater than or equal to V max The voltage signal is converted into "1" and output. At the same time, another relatively small threshold value V is selected. min , it is considered that the data below this threshold are all gas phase signals. When the bubble starts to leave the probe until it is completely separated, the collected voltage value changes from small to large, and the voltage rises to V min The corresponding time point is the starting time point t when the bubble leaves the probe out ; At this time, it will be less than or equal to V min The voltage signal is converted to "0" and output. max With V minWhen the voltage signal is between , it is necessary to further judge the voltage signal state. If the voltage signal is in the voltage drop process, it outputs 0. If it is in the rising state, it outputs 1. If it is equal to the previous voltage value, it is consistent with the output of the previous data point. The detailed binarization process is shown in Table 1 below, where u i is the voltage signal value collected at the ith time, u i-1 is the voltage signal value collected at the i-1th time.

[0072] Table 1 Binarization process

[0073]

[0074] After binarization, the bubble-related parameters are calculated based on the binarized waveform. Figure 7 and Figure 8 As shown, Figure 7 This is a waveform diagram of the voltage data obtained by the conductivity probe assembly 30 before binarization processing. Figure 8 This is a waveform diagram of the voltage data obtained by the conductivity probe assembly 30 after binarization processing.

[0075] After binarization, the voltage signal is converted into a binary rectangular wave form. Next, the rising edge and falling edge in the voltage signal are judged and the specific time points are obtained. The rising edge corresponds to the moment when the bubble contacts the probe, and the falling edge corresponds to the moment when the bubble leaves the probe. The specific method is: the binarized data is traversed and differentiated. When the first-order derivative is negative, it indicates that the time corresponding to this point is the starting point of the descent, and the probe enters the bubble from the liquid phase at this moment; and when the first-order derivative is positive, it indicates that this point corresponds to the starting point of the rise, that is, the probe returns to the liquid phase from the bubble at this moment.

[0076] Since the values ​​of the bubble rate, bubble chord length and gas content are calculated by combining the time point data when the first probe 311 and the second probe 312 pass through the same bubble, the rising starting point and the falling starting point of the first probe 311 and the second probe 312 need to be matched one-to-one to ensure that the two sets of falling starting points and rising starting points generated by the probe group 31 when measuring the same bubble correspond correctly, and invalid bubbles that the first probe 311 and the second probe 312 do not pass through at the same time are eliminated, so that the calculation accuracy of two-phase flow parameters such as bubble rate, bubble chord length and gas content is well guaranteed.

[0077] The above steps can be used to obtain the contact time and separation time of all effective bubbles measured by the probe in a set of experiments. Combined with the above formulas for bubble velocity, bubble chord length, and local average gas fraction, the parameter calculation can be completed.

[0078] In one embodiment of the present invention, Figure 1As shown, the base 20 may include: a base body 21 and a base cover 22, the base body 21 is connected to the detection tube segment 10, the base body 21 is provided with a first perforation, the first perforation extends along the second direction, the first perforation passes through the base body 21 and is connected to the detection tube segment 10, and the probe barrel 32 is passed through the first perforation; the base cover 22, the base cover 22 is provided on the side of the base body 21 away from the detection tube segment 10 in the second direction, the base cover 22 is fastened to the base body 21, the base cover 22 is provided with a second perforation, the second perforation passes through the base cover 22 along the second direction, and the probe barrel 32 is passed through the second perforation.

[0079] In this embodiment, the base 20 includes a base body 21 and a base cover 22. The base body 21 is connected to the detection tube segment 10, and the base cover 22 is fastened to the base body 21. The base body 21 is provided with a first perforation, and the base cover 22 is provided with a second perforation. The probe barrel 32 is penetrated through the first perforation and the second perforation along the second direction. Exemplarily, the base body 21 and the detection tube segment 10 can be welded and connected. The aperture size of the opening of the detection tube segment 10 and the base body 21 can be larger than the maximum value of the multiple probe groups 31 extending in the first direction, so that the conductivity probe assembly 30 can be conveniently assembled and fixed with the base body 21 and extended into the detection tube segment 10, so that the probe group 31 can be conveniently assembled into the detection tube segment 10 from the opening.

[0080] In this embodiment, the base cover 22 is arranged on the side of the base body 21 away from the detection tube section 10 and is tightly connected to the base body 21, which facilitates the assembly of the base body 21 and the base cover 22. The base cover 22 is provided with a second perforation to facilitate the probe barrel 32 to pass through the base 20, thereby facilitating the electrical connection between the data acquisition component 50 and the probe group 31. For example, the data acquisition component 50 can be connected to the probe group 31 through a wire, for example, the wire can be inserted into the probe barrel 32 to be connected to the probe group 31 arranged in the detection tube section 10, or the first probe 311 and the second probe 312 in the probe group 31 can also continue to extend along the extension direction of the probe barrel 32, so that the first probe 311 and the second probe 312 can extend out of the base 20 along the probe barrel 32, thereby conveniently connecting with the data acquisition component 50.

[0081] In some examples of the present invention, Figure 1 As shown, the device 100 for measuring the gas content in the boiler tube also includes a fixing part 40, which is sleeved on the probe cylinder 32 and located between the base cover 22 and the base body 21, wherein the fixing part 40 is an elastic part, and the fixing part 40 is configured to deform under the pressure of the base cover 22 and the base body 21 and clamp the probe cylinder 32 to fix the conductivity probe assembly 30.

[0082] In this embodiment, a fixing part 40 is provided between the base cover 22 and the base body 21. The fixing part 40 is an elastic part and is sleeved on the probe barrel 32. The fixing part 40 is configured to deform and clamp the probe barrel 32 under the pressure of the base cover 22 and the base body 21 to fix the conductivity probe assembly 30. For example, when the base cover 22 and the base body 21 are threadedly fastened, as the base cover 22 is gradually tightened with the base body 21 along the second direction, the fixing part 40 is compressed and deformed under the pressure and limiting action of the base cover 22 and the base body 21, thereby gradually clamping the sleeved probe barrel 32 in the circumferential direction, so that the probe barrel 32 is gradually fixed to the base 20 through the fixing part 40. When the base cover 22 is removed from the base body 21, as the base cover 22 is away from the base body The probe barrel 32 is gradually released from the fixing member 40 and the fixing member 40 is gradually restored to its initial state, so that the fixing member 40 gradually eliminates the squeezing of the probe barrel 32, and the probe barrel 32 can automatically move in the first through-hole and the second through-hole along the second direction, so that the assembly of the conductivity probe assembly 30 and the base 20 is facilitated, and when the conductivity probe assembly 30 is assembled with the base 20 and the detection tube segment 10, the conductivity probe assembly 30 is assembled with the base 20 first and then with the detection tube segment 10. The conductivity probe assembly 30 can adjust the relative position of the probe group 31 to the inner wall in the radial direction in the detection tube segment 10 by moving the probe barrel 32 along the second direction, so that the arrangement position of the probe group 31 in the detection tube segment 10 can be flexibly and conveniently adjusted, so that the probe group 31 can better measure the gas content of the fluid in the detection tube segment 10.

[0083] In one example of the present invention, Figure 1 As shown, in the second direction, a first mating groove 211 is provided at one end of the base body 21 facing the base cover 22, and the first mating groove 211 extends in a ring shape along the circumference of the first through-hole. A second mating groove 221 is provided at one end of the base cover 22 facing the base body 21, and the second mating groove 221 extends in a ring shape along the circumference of the second through-hole. The second mating groove 221 cooperates with the first mating groove 211 to define a fixing cavity, and the fixing member 40 is arranged in the fixing cavity.

[0084] In this embodiment, the base body 21 and the base cover 22 are respectively provided with a first mating groove 211 and a second mating groove 221. The first mating groove 211 and the second mating groove 221 cooperate to define a fixing cavity. The fixing member 40 is disposed in the fixing cavity. The structure is simple. The fixing cavity provides a good arrangement space for the fixing member 40 after the base body 21 and the base cover 22 are fastened together, so that the fixing member 40 can cooperate with the base body 21 and the base cover 22 to clamp and fix the probe barrel 32 more stably. The inner wall of the fixing cavity can limit and guide the deformation of the fixing member 40, so that the fixing member 40 can stably clamp and fix the probe barrel 32 after deformation, thereby making the assembly and fixation of the probe barrel 32 on the base 20 more stable and reliable, and improving the fixation stability and reliability of the conductivity probe assembly 30. Optionally, the fixing member 40 can be a thin elastic metal sheet. The shape of the fixing member 40 can be adapted to the shape of the fixing cavity. The first mating groove 211 and the second mating groove 221 can be tapered grooves.

[0085] In one embodiment of the present invention, Figure 1 As shown, the probe cylinder body 32 can also include a main cylinder portion 321, the main cylinder portion 321 extends along the second direction, and multiple tube portions 322 are connected to the main cylinder portion 321, and the two ends of the detection tube segment 10 in the first direction are respectively a first connecting end and a second connecting end, and the detection ends of the multiple probe groups 31 all extend along the first direction toward the first connecting end, wherein the minimum spacing between the detection end of the probe group 31 and the end face of the first connecting end in the first direction is formed as a first spacing, and the spacing between the end face of the main cylinder portion 321 and the end face of the second connecting end in the first direction is formed as a second spacing, the ratio of the first spacing to the inner diameter of the detection tube segment 10 is greater than 9, and the ratio of the second spacing to the inner diameter of the detection tube segment 10 is greater than 4.

[0086] In this embodiment, the probe cylinder body 32 also includes a main cylinder portion 321, which extends along the second direction and is connected to multiple tube portions 322. For example, the main cylinder portion 321 can be provided with multiple connecting holes, and the multiple tube portions 322 are arranged one-to-one with the multiple connecting holes. The tube portions 322 and the main cylinder portion 321 can be connected by welding so that the cavity of the tube portion 322 is connected to the cavity of the main cylinder portion 321 through the connecting hole, wherein the tube portion 322 connected to one end of the main cylinder portion 321 can be an integral part with the main cylinder portion 321, and can thus be formed by bending.

[0087] In this embodiment, the two ends of the detection pipe section 10 in the first direction are respectively the first connecting end and the second connecting end. For example, the first connecting end and the second connecting end can be formed with connecting flanges for convenient flange connection with the pipeline 200 to be detected, so as to facilitate the assembly and disassembly of the device 100 for measuring the gas content in the boiler tube and the pipeline 200 to be detected, as well as subsequent repair and maintenance, or the first connecting end and the second connecting end can also be formed with chamfers for welding connection with the pipeline 200 to be detected, or the pipeline 200 to be detected can be directly modified to form the detection pipe section 10.

[0088] In this embodiment, the detection ends of the multiple probe groups 31 all extend along the first direction toward the first connection end. Then, in the multiple probe groups 31, the first end 3111 of the first probe 311 and the second end 3121 of the second probe 312 are both facing the first connection end. For example, in this embodiment, the fluid in the detection tube section 10 can flow from the first connection end to the second connection end along the first direction, so that the detection end of the probe group 31 is facing the incoming direction of the fluid to meet the measurement needs of the conductivity probe assembly 30 for the fluid. The direction of the detection end of the probe group 31 in this embodiment can be set accordingly according to the flow direction of the fluid.

[0089] In this embodiment, the minimum spacing between the detection end of the probe group 31 and the end face of the first connecting end in the first direction is the first spacing, that is, in the multiple probe groups 31, the minimum spacing between the probe tip and the end face of the first connecting end in the first direction is the first spacing, and the ratio of the first spacing to the inner diameter of the detection tube section 10 is greater than 9, so that the probe group 31 can be sufficiently far away from the end face of the first connecting end, thereby reducing the influence of eddy currents generated by structural changes at the first connecting end on the measurement, so that the fluid can have a stable flow state when flowing to the probe group 31, so that the device 100 for measuring the gas content in the boiler tube can perform detection operations more stably.

[0090] In this embodiment, the distance between the main cylinder portion 321 and the end surface of the second connecting end in the first direction is formed as a second distance, and the ratio of the second distance to the inner diameter of the detection tube section 10 is greater than 4, so as to reduce the influence of eddy currents generated by structural changes at the second connecting end on the measurement, so that the device 100 for measuring the gas content in the boiler tube can perform detection operations more stably.

[0091] In some embodiments of the present invention, Figure 2 and Figure 3 As shown, the multiple probe groups 31 include a first probe group 301, a second probe group 302 and a third probe group 303. The first probe group 301, the second probe group 302 and the third probe group 303 are arranged in sequence in the second direction. In the first direction, the detection ends of the first probe group 301, the second probe group 302 and the third probe group 303 are staggered in sequence along the first direction.

[0092] In this embodiment, the multiple probe groups 31 include a first probe group 301, a second probe group 302, and a third probe group 303, which are arranged in sequence and spaced apart in the second direction. The detection ends of the first probe group 301, the second probe group 302, and the third probe group 303 are staggered in sequence along the first direction. The structure is simple and the arrangement is reasonable, so that the first probe group 301, the second probe group 302, and the third probe group 303 can measure the local average gas content at different cross-sections of the detection pipe section 10, so that the conductivity probe assembly 30 can perform more comprehensive detection of the gas content of the fluid in the first direction and the second direction, so as to better monitor the flow changes and gas-liquid phase distribution of the fluid in the detection pipe section 10, thereby more effectively monitoring the deterioration of heat transfer, and enabling the device 100 for measuring the gas content in the boiler tube to better provide early warning of heat transfer deterioration.

[0093] In one embodiment of the present invention, the second probe group 302 can be located in the middle of the detection tube section 10 in the second direction, and the first probe group 301, the second probe group 302, and the third probe group 303 can be evenly spaced along the second direction. This can make the distribution of the three probe groups 31 within the detection tube section 10 more uniform, allowing the conductivity probe assembly 30 to perform better detection.

[0094] In some embodiments of the present invention, reference Figure 1 As shown, the detection pipe section 10 is detachably connected to the pipeline 200 to be detected, or the detection pipe section 10 is fixedly connected to the pipeline 200 to be detected.

[0095] In this embodiment, the detection pipe section 10 is detachably connected to the pipeline to be inspected 200, facilitating assembly of the apparatus 100 for measuring the gas content in boiler tubes and the pipeline to be inspected 200, as well as subsequent disassembly and maintenance. The detection pipe section 10 is fixedly connected to the pipeline to be inspected 200, for example, by welding the detection pipe section 10 to the pipeline to be inspected 200 or forming a portion of the pipeline to be inspected 200. This makes the overall structure of the detection pipe section 10 and the pipeline to be inspected 200 more stable and reliable, allowing fluid to flow more stably through the detection pipe section 10, thereby enabling the detection pipe section 10 to transport fluid more stably to a certain extent.

[0096] In some embodiments of the present invention, Figure 1 As shown, the data acquisition component 50 may include: a data acquisition card 51 and a wire and an acquisition system 52 . The data acquisition card 51 is connected to the conductivity probe component 30 via a wire; and the acquisition system 52 is in communication with the data acquisition card 51 .

[0097] In this embodiment, the data acquisition assembly 50 includes a data acquisition card 51 and wires. The data acquisition card 51 is connected to the conductivity probe assembly 30 via the wires, resulting in a simple structure and easy assembly. The acquisition system 52 is communicatively connected to the data acquisition card 51, enabling the acquisition system 52 to cooperate with the data acquisition card 51 to process data collected by the conductivity probe assembly 30, thereby meeting the requirements of the apparatus 100 for measuring the gas content in boiler tubes. For example, the acquisition system 52 and the data acquisition card 51 may be connected via a cable or wirelessly.

[0098] The following will refer to Figures 1-10 A device 100 for measuring the air content in a boiler tube according to a specific embodiment of the present invention is described.

[0099] like Figures 1-10 As shown, the device 100 for measuring the gas content in a boiler tube includes a detection tube section 10 , a base 20 , a conductivity probe assembly 30 , a data acquisition assembly 50 and a fixing member 40 .

[0100] The inner and outer diameters of the detection pipe section 10 are the same as those of the pipeline to be detected 200. The material of the detection pipe section 10 is the same as that of the pipeline to be detected 200. The pipeline to be detected 200 can be a water-cooled wall tube of a boiler in a thermal power plant. The detection pipe section 10 extends along a first direction and has two ends respectively, a first connecting end and a second connecting end. The first connecting end and the second connecting end are respectively formed with connecting flanges that are flange-connected to the pipeline to be detected 200. In another embodiment, chamfers can also be set at both ends of the detection pipe section 10 and welded to the pipeline to be detected 200.

[0101] The base 20 includes a base body 21 and a base cover 22. The base body 21 extends along a second direction, which is perpendicular to the first direction and is an up-down direction. One end of the base body 21 is welded to the detection tube segment 10. Specifically, a hole is punched at the position where the detection tube segment 10 is connected to the base body 21, and the hole is chamfered so as to be fixed to the base body 21 by argon arc welding. The hole diameter can be larger than the longest probe group 31 in the conductivity probe assembly 30 along the first direction, so that the probe group 31 can easily pass through the hole along the second direction and enter the detection tube segment 10. The other end of the base body 21 is threadedly connected to the base cover 22. The base body 21 is provided with a first through-hole, and the base cover 22 is provided with a second through-hole. The first through-hole and the second through-hole both extend along the second direction and are connected. The base body 21 is provided with a first matching groove 211, and the second base body 21 is provided with a second matching groove 221. The first matching groove 211 and the second matching groove 221 cooperate to define a fixing cavity. The fixing part 40 is a thin metal sheet and is arranged in the fixing cavity.

[0102] The conductivity probe assembly 30 includes a probe barrel 32, a first seal 33, a second seal 34 and three probe groups 31. The probe barrel 32 includes a main barrel portion 321 and a tube portion 322. The main barrel portion 321 extends along the second direction and is penetrated by a first through-hole and a second through-hole. One end of the main barrel portion 321 passes through the base cover 22, and the other end of the main barrel portion 321 extends into the detection tube segment 10. The base body 21 is also provided with two weight-reducing grooves 201. The two weight-reducing grooves 201 are arranged at intervals along the second direction and are connected to the first through-hole. This can reduce the weight of the base body 21, making it easier to carry and transfer the base body 21 and the detection tube segment 10 when assembled, and can reduce the contact area between the main barrel portion 321 and the first through-hole. This allows the main barrel portion 321 to more smoothly penetrate the first through-hole and move relative to the base body 21 along the second direction.

[0103] There are three tubes 322, which are evenly spaced in the second direction and extend along the first direction. The three tubes 322 are located on the same side of the main tube 321 facing the first connection end in the first direction and are located in the detection tube section 10. In the second direction, the three probe groups 31 are the first probe group 301, the second probe group 302 and the third probe group 303 in the direction facing the base 20. The detection ends of the first probe group 301, the second probe group 302 and the third probe group 303 are staggered in the first direction. In the second direction, the detection ends of the probe groups 31 are staggered in the first direction. The probe group 31 includes a first probe 311 and a second probe 312 arranged in sequence toward the base 20. The tip of the first probe 311 forms a first end 3111, and the tip of the second probe 312 forms a second end 3121. The first end 3111 and the second end 3121 constitute the detection end of the probe group 31. The first end 3111 of the first probe 311 and the second end 3121 of the second probe 312 are staggered in the first direction, and the first end 3111 of the first probe 311 is closer to the first connection end than the second end 3121 of the second probe 312 in the first direction.

[0104] The tube portion 322 is formed with a probe outlet, and the first probe 311 and the second probe 312 extend out of the probe outlet along the first direction. The first seal 33 is arranged in the tube portion 322 to seal the probe group 31 and the tube portion 322. The second seal 34 is filled between the first seal 33 and the first probe 311 and the second probe 312 of the probe group 31 to further improve the sealing effect. The second seal 34 is a high-temperature and corrosion-resistant silicone sealant, which can be used for a long time under conditions of 300°C to 400°C.

[0105] The other ends of the first probe 311 and the second probe 312 may extend into the main tube portion 321 and may extend along the second direction to be flush with an end of the main tube portion 321 extending out of the base 20 .

[0106] The data acquisition component 50 includes a guide, a data acquisition card 51 and an acquisition system 52. The data acquisition card 51 is connected to the three probe groups 31 via wires, and the acquisition system 52 and the data acquisition card 51 can be connected wirelessly.

[0107] In this embodiment, the first probe 311 and the second probe 312 are made of Hastelloy C276, which has a maximum temperature resistance of 600°C and a maximum pressure resistance of 35 MPa. The outer surfaces of the first probe 311 and the second probe 312 are coated with a Teflon coating, which not only provides insulation but also adapts to the fluid environment in the boiler tube. The probe barrel 32 is a stainless steel tube. The probe barrel 32 and the three probe groups 31 form a grid-type conductivity probe structure. To make the processed probe tips suitable for measuring fluid parameters in the boiler tube, the overall gears and structure of the probes can be reasonably configured as needed to have an appropriate size and good conductivity. For example, when the grid-type conductivity probe structure is processed and manufactured, the manufacturing process is as follows:

[0108] 1) Select a stainless steel tube about 20 cm long and make a small hole in it at 7.5 cm and 9 cm from one end.

[0109] 2) Select two C276 alloy wires of a certain length and a diameter of 1 mm as probes as needed, apply Teflon insulation coating to each of them, and reserve the needle tip and needle tail parts.

[0110] 3) Align the two alloy steel wires and insert them in parallel from one end of the stainless steel pipe. After the two alloy steel wires reach the outlet at the other end, measure the relative position of the two stainless steel wires.

[0111] 4) Insert the first sealing member 33 through the two stainless steel wires and embed it into the outlet at the other end of the stainless steel tube.

[0112] 5) The distance between the needle tips of the two C276 alloy steel wires can be 2mm, 1mm, etc. Then, apply silicone sealant to the gap between the fixed component and the C276 alloy steel wire to secure the alloy steel wire in place. Then, use a multimeter to test the corresponding areas twice to ensure good insulation between the two alloy steel wires, between the alloy steel wire and the stainless steel tube, and between the alloy steel wire head and the rest of the wire.

[0113] 6) To make the probe measurement more accurate and reduce the impact on the flow channel, the stainless steel tube and the two probes were bent 90° into an "L" shape about 6 cm away from the needle tip.

[0114] 7) After completing the above steps, take two C276 alloy wires with a certain length and a diameter of 1mm, which have been brushed with Teflon insulation coating, as probes. After reaching the position of the 7.5cm small hole, use a small hook to hook the alloy wire to a certain length. Then, the stainless steel tube used to constitute the tube part 322 is covered with the probe and welded to the position of the small hole, and then repeat steps 4) to 5).

[0115] 8) Then repeat step 7) at the 9cm position.

[0116] 9) Mark the first probe 311 and the second probe 312 corresponding to each probe group 31, and seal the ports of the grid-type conductivity probe assembly 30 again.

[0117] When assembling the conductivity probe assembly 30 with the base 20 and the detection tube section 10, the conductivity probe assembly 30 and the base 20 are assembled first, and the three probe groups 31 and the probe barrel 32 are assembled with the base body 21 as a whole. The main barrel portion 321 of the probe barrel 32 extends from the side of the base body 21 away from the base cover 22 into the first through-hole and out of the first through-hole. The main barrel portion 321 passes through the fixing member 40 and passes through the second through-hole of the base cover 22 and out of the second through-hole, so that the conductivity probe assembly 30 and the base 20 are preliminarily assembled. The preliminarily assembled conductivity probe assembly 30 and the base 20 are then assembled with the detection tube section 10 as a whole. The probe group 31 extends into the detection tube section 10, and the base body 21 and the detection tube section 10 are vertically welded. When checking the welding position for leaks and leakage, After the welding process is complete, the conductivity probe assembly 30 can continue to move in the second direction toward the detection tube segment 10. When the probe group 31 contacts the lower wall of the detection tube segment 10, a mark is made on the main tube portion 321. The conductivity probe assembly 30 then moves in the opposite direction. When the probe group 31 contacts the upper wall of the detection tube segment 10, a mark is also made on the grid-shaped conductivity tube body. The conductivity probe assembly 30 is moved midway between the two marked points so that the plurality of probe groups 31 are positioned centrally within the detection tube segment 10 in the second direction. The base cover 22 and the base body 21 are fastened in place, so that the fixing member 40 clamps and secures the probe tube body 32, sealing the base 20 and the conductivity probe assembly 30, thereby securing the conductivity probe assembly 30 relative to the detection tube segment 10. The data acquisition assembly 50 can be comprised of an amplifier circuit board, a signal acquisition program, and a signal post-processing program. The data acquisition component 50 can transmit the voltage signal collected by the conductivity probe component 30 to the acquisition program, and convert the signal data into the required fluid parameters such as local average gas content, bubble velocity, bubble chord length, and dryness.

[0118] The amplifier circuit part is mainly based on the principle of the reverse operational amplifier circuit. Its main function is to process the collected voltage signal so that it can fully reflect the changes in the two-phase flow in the pipe.

[0119] The signal acquisition program uses the NI system for data acquisition and is written based on the LabVIEW (Laboratory Virtual Instrument Engineering Workbench) software platform. It can realize data acquisition and storage of the probe group, and has a corresponding visual panel to display the changes in the voltage signal.

[0120] The signal post-processing procedure mainly includes five steps as mentioned above: voltage signal preprocessing, signal binarization, rising edge and falling edge judgment, effective bubble judgment and two-phase flow parameter calculation. After processing, the collected signal becomes an ideal rectangular wave state, which can clearly reflect the flow state of the gas-liquid two-phase.

[0121] This embodiment provides an effective means for monitoring the gas content of fluid within boiler tubes in thermal power plants that fail to monitor the gas content. The device 100 for measuring the gas content within boiler tubes can be adapted to actual power plant factors and, with minor modifications, provide a technical option for thermal power plants. The conductivity probe assembly 30 of the device 100 for measuring the gas content within boiler tubes can simultaneously measure two-phase flow parameters at different locations within the tubes. The large number of probe groups 31 and their wide distribution significantly reduce the likelihood of the device 100 failing to monitor due to damage to some of the probe groups 31. By monitoring the gas content, the flow pattern and gas-liquid phase distribution within the boiler tubes can be effectively determined. When a high concentration of gas near the tube wall is present, the boiler's operating state can be adjusted promptly, effectively preventing deterioration of heat transfer within the tubes and avoiding major leakage issues caused by overheating of the tube wall in thermal power boilers. Compared to estimating fluid heat transfer by measuring wall temperature, extending the probe group 31 into the test tube section 10 for measurement can more accurately and accurately determine the heat transfer conditions of the fluid within the test tube section 10.

[0122] During the calibration experiment, the first probe group 301, the second probe group 302, and the third probe group 303 can be calibrated simultaneously to verify the accuracy of each probe group 31 during measurement. Table 2 below shows the relative error data of the bubble rate measured by the first probe group 301, Table 3 shows the relative error data of the bubble rate measured by the second probe group 302, and Table 4 shows the relative error data of the bubble rate measured by the third probe group 303:

[0123] Table 2 Relative error analysis of the bubble velocity measured by the first probe group 301

[0124]

[0125] Table 3 Relative error analysis of the second probe group 302 measuring the bubble rate

[0126]

[0127] Table 4 Relative error analysis of the third probe group 303 measuring the bubble rate

[0128]

[0129] The calibration test results show that the average measurement error of the bubble velocity by each probe group 31 of the conductivity probe assembly 30 is less than 5%, and the maximum relative error is less than 10%. Therefore, the device 100 for measuring the gas content in a boiler tube of this embodiment has a high accuracy in measuring the bubble velocity, and can be well used to measure two-phase flow parameters such as gas content in actual boiler pipelines. In addition, it can well monitor the deterioration of heat transfer in the boiler tube, effectively prevent problems such as pipeline overheating caused by deteriorated heat transfer in the boiler tube, and ensure more reliable boiler operation.

[0130] The device 100 for measuring the gas content in the boiler tube of this embodiment can be arranged in different pipes in the boiler steam-water system as needed. For example, it can be installed in heating surface pipes such as water-cooling pipe walls to monitor heat transfer deterioration and provide early warning. It can also be installed on non-heating surface pipes such as condenser pipes to detect gas content, etc., so as to better monitor the flow of fluids in the heavy pipes of the steam-water system.

[0131] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying 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 therefore should not be understood as limiting the present invention.

[0132] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0133] In the present invention, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be understood broadly. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0134] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0135] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. A device for measuring the gas content in a boiler tube, arranged in a pipeline to be tested (200) of the boiler, characterized in that: include: A detection pipe section (10), the detection pipe section (10) is connected in series to the pipeline to be detected (200), and the detection pipe section (10) extends along a first direction; a base (20), the base (20) extending along a second direction and connected to the detection tube section (10), the second direction being perpendicular to the first direction; A conductivity probe assembly (30), the conductivity probe assembly (30) being mounted on the base (20), the conductivity probe assembly (30) comprising a plurality of probe groups (31), the probe groups (31) extending along the first direction, the detection ends of the probe groups (31) extending into the detection pipe section (10) to measure the gas content of the fluid in the detection pipe section (10); A data acquisition component (50) is electrically connected to the plurality of probe groups (31).

2. The device for measuring the gas content in boiler tubes according to claim 1, characterized in that: The probe group (31) comprises: a first probe (311) and a second probe (312); one end of the first probe (311) extending into the detection tube section (10) forms a first end (3111); one end of the second probe (312) extending into the detection tube section (10) forms a second end (3121); the first end (3111) and the second end (3121) constitute the detection end; the first end (3111) and the second end (3121) are staggered in the first direction.

3. The device for measuring the gas content in boiler tubes according to claim 1, characterized in that: The conductivity probe assembly (30) further comprises: A probe cylinder (32), wherein the probe cylinder (32) is provided with a plurality of tubes (322), the tubes (322) extending along the first direction and forming a probe outlet, the plurality of tubes (322) being arranged at intervals in the second direction, the plurality of probe groups (31) being arranged in a one-to-one correspondence with the plurality of tubes (322), and the probe groups (31) extending out of the probe outlet along the first direction; A first sealing member (33) is provided on the tube portion (322), and the first sealing member (33) is sealed and connected between the probe group (31) and the inner wall of the tube portion (322).

4. The device for measuring the gas content in boiler tubes according to claim 3, characterized in that: The base (20) comprises: A base body (21), the base body (21) is connected to the detection tube section (10), the base body (21) is provided with a first through-hole, the first through-hole extends along the second direction, the first through-hole passes through the base body (21) and is in communication with the detection tube section (10), and the probe barrel (32) is provided in the first through-hole; A base cover (22), the base cover (22) is arranged on a side of the base body (21) away from the detection tube section (10) in the second direction, the base cover (22) is fastened to the base body (21), the base cover (22) is provided with a second through-hole, the second through-hole passes through the base cover (22) along the second direction, and the probe barrel (32) is passed through the second through-hole.

5. The device for measuring the gas content in boiler tubes according to claim 4, characterized in that: The invention also includes a fixing member (40), which is sleeved on the probe barrel (32) and located between the base cover (22) and the base body (21), wherein the fixing member (40) is an elastic member, and the fixing member (40) is configured to deform under the pressure of the base cover (22) and the base body (21) and clamp and fix the probe barrel (32) to fix the conductivity probe assembly (30).

6. The device for measuring the air content in a boiler tube according to claim 5, characterized in that: In the second direction, a first matching groove (211) is provided at one end of the base body (21) facing the base cover (22), and the first matching groove (211) extends in a ring shape along the circumference of the first through-hole. A second matching groove (221) is provided at one end of the base cover (22) facing the base body (21), and the second matching groove (221) extends in a ring shape along the circumference of the second through-hole. The second matching groove (221) cooperates with the first matching groove (211) to define a fixing cavity, and the fixing member (40) is arranged in the fixing cavity.

7. The device for measuring the gas content in a boiler tube according to any one of claims 3 to 6, characterized in that: The probe barrel (32) further comprises a main barrel portion (321), the main barrel portion (321) extending along the second direction, a plurality of the tube portions (322) being connected to the main barrel portion (321), the two ends of the detection tube section (10) in the first direction being respectively a first connecting end and a second connecting end, and the detection ends of the plurality of the probe groups (31) all extending along the first direction toward the first connecting end, wherein, The minimum distance between the detection end of the probe group (31) and the end face of the first connecting end in the first direction forms a first distance, the distance between the main cylinder portion (321) and the end face of the second connecting end in the first direction forms a second distance, the ratio of the first distance to the inner diameter of the detection tube section (10) is greater than 9, and the ratio of the second distance to the inner diameter of the detection tube section (10) is greater than 4.

8. The device for measuring the gas content in a boiler tube according to any one of claims 1 to 6, characterized in that: The plurality of probe groups (31) include a first probe group (301), a second probe group (302) and a third probe group (303); the first probe group (301), the second probe group (302) and the third probe group (303) are arranged in sequence and spaced apart in the second direction; in the first direction, the detection ends of the first probe group (301), the second probe group (302) and the third probe group (303) are arranged in sequence and staggered along the first direction.

9. The device for measuring the gas content in a boiler tube according to any one of claims 1 to 6, characterized in that: The detection pipe section (10) is detachably connected to the pipeline to be detected (200), or the detection pipe section (10) is fixedly connected to the pipeline to be detected (200).

10. The device for measuring the gas content in a boiler tube according to any one of claims 1 to 6, characterized in that: The data acquisition component (50) comprises: A data acquisition card (51) and a wire, wherein the data acquisition card (51) is connected to the conductivity probe assembly (30) via the wire; An acquisition system (52) is communicatively connected to the data acquisition card (51).

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