A kind of HTR-PM fuel unloading system ball route pipeline health monitoring system

Abstract

The application discloses a kind of HTR-PM fuel unloading system ball route pipeline health monitoring system, the monitoring system includes first non-shield section transducer, second non-shield section transducer, first shield section transducer, second shield section transducer and multichannel acoustic emission detector, first non-shield section transducer, second non-shield section transducer, first shield section transducer, second shield section transducer are electrically connected with multichannel acoustic emission detector;The first non-shield section transducer and second non-shield section transducer are respectively fixed in the upstream and downstream of non-shield section fuel unloading system pipeline pipe fitting;The first shield section transducer and second shield section transducer are respectively fixed in the upstream and downstream of fuel unloading system pipeline pipe fitting. Fuel ball in fuel loading and unloading system ball route pipeline can be long-term continuously monitored state, and the flow trajectory of fuel ball can be tracked and positioned.

Description

Technical Field

[0001] This invention belongs to the technical field of pipeline health monitoring systems, specifically relating to a health monitoring system for the ball-shaped pipeline of an HTR-PM fuel unloading system. Background Technology

[0002] The pebble bed high-temperature gas-cooled reactor (HTR-PM) uses helium, a chemically inert gas with excellent thermal properties, as the coolant. It uses fully ceramic-coated fuel pellets and high-temperature resistant graphite as the moderator and core structural material. A single reactor can contain hundreds of thousands of fuel pellets, each approximately 60mm in diameter. The fuel pellets are typically loaded continuously into the core from the top. The fuel loading and unloading system performs reactive unloading and fuel pellet circulation. Under equilibrium conditions, it can achieve a rapid circulation of 12,000 fuel pellets per day per reactor and sorting of pellets with a diameter of 56.5mm or less, with a count rate and sorting accuracy of 99.99%. In case of fuel pellet jamming or breakage, specialized equipment can be used at the unloading end to clear the jammed pellets. Therefore, the fuel unloading system is a crucial component of the HTR-PM; quickly identifying the status of broken pellets and the location of jammed pellets improves system stability.

[0003] High-temperature gas-cooled reactors currently use sphere transfer devices to detect the passage of fuel spheres. When a fuel sphere passes through a fixed-position sphere transfer device, the eddy current principle affects the impedance in the equilibrium state. When the impedance exceeds a set threshold, the sphere transfer device determines that the fuel sphere has passed that position. However, the fuel loading and unloading system has a long sphere passage section, and the limited number of sphere transfer devices cannot accurately determine the position where the sphere is stuck. In addition, the eddy current impedance value is affected by the temperature of the medium inside the pipe, resulting in low accuracy and stability of sphere transfer. Summary of the Invention

[0004] To address the aforementioned issues, this invention provides a health monitoring system for the HTR-PM fuel unloading system's ball path pipeline, used to monitor the status of fuel balls within the HTR-PM fuel unloading system's ball path pipeline in real time, thereby improving the accuracy and stability of fuel ball positioning within the ball path pipeline.

[0005] To achieve the above objectives, the present invention provides a health monitoring system for the HTR-PM fuel unloading system's ball-shaped pipeline, comprising a first unshielded section transducer, a second unshielded section transducer, a first shielded section transducer, a second shielded section transducer, and a multi-channel acoustic emission detector. The first unshielded section transducer, the second unshielded section transducer, the first shielded section transducer, and the second shielded section transducer are electrically connected to the multi-channel acoustic emission detector. The first unshielded section transducer and the second unshielded section transducer are respectively fixed upstream and downstream of the unshielded section fuel unloading system pipeline fittings. The first shielded section transducer and the second shielded section transducer are respectively fixed upstream and downstream of the fuel unloading system pipeline fittings.

[0006] Furthermore, the first unshielded section transducer and the second unshielded section transducer have the same structure as the first shielded section transducer and the second shielded section transducer.

[0007] Furthermore, the first shielded section transducer and the second shielded section transducer are sleeve structures.

[0008] Furthermore, the first shielded section transducer includes a piezoelectric crystal portion, a sleeve portion, and a waveguide rod portion. The piezoelectric crystal portion contacts the waveguide rod portion but does not contact the sleeve portion. The waveguide rod portion is disposed within the sleeve portion.

[0009] Furthermore, the sleeve portion of the first shielded section transducer and the inside of the waveguide of the first shielded section transducer are filled with sound-absorbing material.

[0010] Furthermore, the first unshielded section transducer, the second unshielded section transducer, the first shielded section transducer, and the second shielded section transducer are connected to the same multi-channel acoustic emission detector via connecting lines.

[0011] Furthermore, the first unshielded section transducer, the second unshielded section transducer, the first shielded section transducer, and the second shielded section transducer are all welded to the outer wall of the fuel unloading system pipeline.

[0012] The monitoring method for the HTR-PM fuel unloading system ball pipeline health monitoring system, as described above, includes the following steps:

[0013] As the fuel ball rolls downwards within the fuel unloading system pipeline, the first unshielded section transducer, the second unshielded section transducer, the first shielded section transducer, and the second shielded section transducer collect sound signals. After the sound signals are calibrated by a multi-channel acoustic emission detector to shield the interference waveform, characteristic waveforms are obtained from each transducer. Based on whether the first unshielded section transducer, the second unshielded section transducer, the first shielded section transducer, and the second shielded section transducer collect characteristic waveforms, it is determined whether ball jamming or ball breakage has occurred. If ball jamming occurs, the location of the jamming is determined.

[0014] Furthermore, by comparing and analyzing the waveform characteristics of each transducer, the size of the fuel pellet fragments can be determined.

[0015] Furthermore, the waveform characteristics are frequency and / or amplitude.

[0016] Compared with the prior art, the present invention has at least the following beneficial technical effects:

[0017] This invention provides a health monitoring system for the HTR-PM fuel unloading system's ball path pipeline. This system can continuously monitor the state of fuel balls within the pipeline and track and locate their flow trajectory. When the fuel balls are in normal operating condition (i.e., no broken or stuck balls), the time-domain acoustic signal collected by the transducer is almost invariant as the fuel balls collide with the inner wall of the pipeline. The spectrum and amplitude response of this acoustic signal are within a fixed threshold. However, if broken or stuck balls are present, the time-domain acoustic signal will change and deviate from the normal threshold. Furthermore, the acoustic signal received by the transducer is unaffected by the temperature of the medium within the pipeline. Therefore, the position of the fuel balls and the presence of broken or stuck balls can be determined by the signals received by transducers positioned at different locations within the pipeline.

[0018] Furthermore, transducers are rationally arranged on the ball-shaped pipeline of the fuel loading and unloading system. Acoustic emission signals under normal operating conditions are collected multiple times and machine learning or manual statistics are performed to limit the threshold of the spectrum and amplitude response of each channel under normal operating conditions to a certain range. When a ball jamming occurs, the transducer downstream of the jamming position cannot receive the acoustic emission signal normally, triggering a threshold alarm. The approximate range of the jammed pipe section can be determined by comparing the locations of the alarmed and non-alarmed transducers.

[0019] Furthermore, the fuel ball rolls in the tube between the two transducers, and the trajectory of the fuel ball is determined by parameters such as the response time and amplitude of the sound time-domain signal from a certain transducer.

[0020] Furthermore, when a ball breakage occurs, the amplitude response of the acoustic emission signal received by the transducer closest to the breakage location will be much greater than the amplitude under normal conditions. This will also trigger the threshold alarm of the transducer at that location. Based on the location of the alarm transducer, the staff can determine the location where the ball may break and accumulate.

[0021] Furthermore, when a fuel pellet breakage occurs, the approximate size of the broken fuel pellets can be determined through comprehensive analysis of signal characteristics.

[0022] The present invention discloses a health monitoring method for the ball path pipeline of an HTR-PM fuel unloading system. By using transducers to collect sound signals, and by observing whether each transducer can collect sound signals and the characteristics of the collected sound signals, the state of the fuel balls in the ball path pipeline of the fuel loading and unloading system can be continuously monitored over a long period of time. The flow trajectory of the fuel balls can be tracked and located, and it can be determined whether the fuel balls are in normal operating conditions. Attached Figure Description

[0023] Figure 1 A perspective view of an HTR-PM fuel ball acoustic emission positioning system for fuel unloading pipelines;

[0024] Figure 2This is a front view of an HTR-PM fuel ball acoustic emission positioning system for fuel unloading pipelines;

[0025] Figure 3 Left view of an HTR-PM fuel ball acoustic emission positioning system for fuel unloading pipelines;

[0026] Figure 4 A top view of an HTR-PM fuel ball acoustic emission positioning system for fuel unloading pipelines;

[0027] Figure 5 Perspective view of the waveguide rod transducer in the shielded section;

[0028] Figure 6 This is the front view of the waveguide rod transducer in the shielded section;

[0029] Figure 7 Left view of the waveguide rod transducer in the shielded section;

[0030] Figure 8 A waveform diagram of an embodiment of the waveform detection under working condition (1);

[0031] Figure 9 A waveform diagram of an embodiment of the waveform detection under working condition (2);

[0032] Figure 10 A waveform diagram of an embodiment of the waveform detection under working condition (3);

[0033] Figure 11 A waveform diagram of an embodiment of the waveform detection under working condition (4);

[0034] Figure 12 A waveform diagram of an embodiment of the waveform detection for working condition (5).

[0035] Explanation of reference numerals in the attached figures:

[0036] 1. Fuel unloading system piping; 2. First unshielded section transducer; 3. Unshielded section fuel unloading system piping fittings; 4. Second unshielded section transducer; 5. Lead shielding of fuel unloading system piping; 6. Shielded section fuel unloading system piping fittings; 7. First shielded section transducer; 8. Second shielded section transducer; 9. Multi-channel acoustic emission detector; 10. Connecting cable between transducer and acoustic emission detector; 7-1. Piezoelectric crystal portion of the first shielded section transducer; 7-2. Sleeve portion of the first shielded section transducer; 7-3. Waveguide rod portion of the first shielded section transducer; 8-1. Piezoelectric crystal portion of the second shielded section transducer; 8-2. Sleeve portion of the second shielded section transducer; 8-3. Waveguide rod portion of the second shielded section transducer. Detailed Implementation

[0037] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0038] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0039] It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of the patent. The description uses lead-shielded and lead-free shielded pipe sections of a fuel unloading system as examples.

[0040] Example 1

[0041] Reference Figure 1 A health monitoring system for HTR-PM fuel unloading system ball-shaped pipeline includes a fuel unloading system pipeline 1, a first unshielded section transducer 2, unshielded section fuel unloading system pipeline fittings 3, a second unshielded section transducer 4, a lead shield for the fuel unloading system pipeline 5, shielded section fuel unloading system pipeline fittings 6, a first shielded section transducer 7, a second shielded section transducer 8, a multi-channel acoustic emission detector 9, and a connecting cable 10 between the transducer and the acoustic emission detector.

[0042] like Figure 1 As shown, the fuel unloading system pipeline 1 comprises four straight pipe sections, three elbows, an unshielded fuel unloading system pipeline fitting 3, and a shielded fuel unloading system pipeline fitting 6. The three elbows connect the four straight pipe sections sequentially to form the fuel unloading system pipeline 1. The fuel unloading system pipeline 1 is divided into an unshielded fuel unloading system pipeline and a shielded fuel unloading system pipeline. The unshielded fuel unloading system pipeline is fitted with unshielded fuel unloading system pipeline fitting 3, and the shielded fuel unloading system pipeline is fitted with shielded fuel unloading system pipeline fitting 6.

[0043] The straight pipes, elbows, unshielded section fittings 3, shielded section fittings 6, and the lead shielding 5 covering the fuel unloading system pipeline may all pose a risk of ball jamming. Furthermore, the lead shielding 5 is filled with lead sand for radiation shielding, which affects the placement of the acoustic emission transducers. Considering the site environment, the fuel unloading system pipeline 1 is divided into shielded and unshielded sections for transducer installation and signal acquisition.

[0044] like Figures 1 to 4 As shown, the first unshielded section transducer 2 and the second unshielded section transducer 4 are respectively arranged upstream and downstream of the unshielded section fuel unloading system pipe fitting 3 where the fuel ball may get stuck, and are fixedly installed on the outer wall of the fuel unloading system pipe 1 by welding or other methods.

[0045] like Figures 1 to 4 As shown, the lead shield 5 of the fuel unloading system pipeline covers the outside of the fuel unloading system pipeline fitting 6 of the shield section, and is filled with lead sand for radiation shielding. Corresponding to the positions of the first shield section transducer 7 and the second shield section transducer 8, through holes are respectively provided for the sleeve portion 7-2 of the first shield section transducer and the sleeve portion 8-2 of the second shield section transducer.

[0046] like Figures 1 to 4 As shown, the first shielding section transducer 7 and the second shielding section transducer 8 are respectively arranged upstream and downstream of the shielding section fuel unloading system pipeline fitting 6 where the fuel ball may get stuck. The sleeve part 7-2 of the first shielding section transducer and the sleeve part 8-2 of the second shielding section transducer pass through the reserved through hole on the lead shield 5 of the fuel unloading system pipeline and are fixedly installed on the outer wall of the fuel unloading system pipeline 1 by welding or other methods.

[0047] like Figure 5 and Figure 6 As shown, the first shielded section transducer 7 is a sleeve-structured waveguide rod transducer, consisting of a piezoelectric crystal portion 7-1, a sleeve portion 7-2, and a waveguide rod portion 7-3. The piezoelectric crystal portion 7-1 is in direct contact with the waveguide rod portion 7-3, but not with the sleeve portion 7-2. The waveguide rod portion 7-3 is not in contact with the sleeve portion 7-2.

[0048] like Figure 5 and Figure 6As shown, the second shielded section transducer 8 consists of a piezoelectric crystal portion 8-1, a sleeve portion 8-2, and a waveguide rod portion 8-3. The piezoelectric crystal portion 8-1 is in direct contact with the waveguide rod portion 8-3. Depending on the site conditions, it can be fixed by bonding or welding and does not contact the sleeve portion 8-2.

[0049] like Figures 5 to 7 As shown, during the propagation of sound waves in the waveguide rod, to reduce the sound energy loss caused by the direct contact of the waveguide rod with lead sand, the first shielded section transducer 7 and the second shielded section transducer 8 adopt a sleeve structure. The waveguide rod part 7-3 of the first shielded section transducer and the waveguide rod part 8-3 of the second shielded section transducer are respectively inserted into the sleeve part 7-2 of the first shielded section transducer and the sleeve part 8-2 of the second shielded section transducer. The sleeve part 7-2 of the first shielded section transducer and the sleeve part 8-2 of the second shielded section transducer pass through the lead shield 5 and should isolate the influence of lead sand on sound energy. The sleeve part 7-2 of the first shielded section transducer, the sleeve part 8-2 of the second shielded section transducer, the waveguide rod part 7-3 of the first shielded section transducer, and the waveguide rod part 8-3 of the second shielded section transducer are fixedly installed on the outer wall of the fuel unloading system pipeline 1 by welding or other means, and the other end of the waveguide rod is in direct contact with the transducer, while the other end of the waveguide rod sleeve is not in contact with the transducer. The space between the sleeve portion 7-2 and the waveguide rod portion 7-3 of the first shielded section transducer is filled with sound-absorbing material. The sleeve portion 8-2 and the waveguide rod portion 8-3 of the second shielded section transducer are filled with sound-absorbing material. In addition to reducing noise interference and reducing sound energy loss during sound wave propagation in the waveguide rod, the sound-absorbing material also serves to support the sleeve and the waveguide rod.

[0050] like Figure 1 As shown, one end of each of the four connecting lines 10 is independently connected to the first unshielded section transducer 2, the second unshielded section transducer 4, the first shielded section transducer 7, and the second shielded section transducer 8, and the other end is connected to the multi-channel acoustic emission detector 9, which can simultaneously collect and monitor the signals received by multiple transducers.

[0051] Example 2

[0052] A method for health monitoring of the ball-shaped pipeline of an HTR-PM fuel unloading system, based on the health monitoring device for the ball-shaped pipeline of the HTR-PM fuel unloading system described in Example 1, includes the following steps:

[0053] Under the influence of gravity or the thrust of other system atmospheres, the fuel ball rolls from top to bottom within the fuel unloading system pipe 1. The first unshielded section transducer 2, the second unshielded section transducer 4, the first shielded section transducer 7, and the second shielded section transducer 8 collect sound signals. After the multi-channel acoustic emission detector 9 adjusts to shield the interference waveform, considering that the waveforms collected by each channel are only the synchronous characteristic waveforms of the fuel ball flowing through the transducers, the presence or absence of a stuck fuel ball and broken fuel balls is determined based on whether the first unshielded section transducer 2, the second unshielded section transducer 4, the first shielded section transducer 7, and the second shielded section transducer 8 collect characteristic waveforms. If a stuck fuel ball occurs, its location is determined.

[0054] When the fuel sphere successfully passes through the unshielded fuel unloading system pipe fitting 3 and the shielded fuel unloading system pipe fitting 6, the first unshielded section transducer 2 and the second unshielded section transducer 4 upstream and downstream of the unshielded fuel unloading system pipe fitting 3, and the first shielded section transducer 7 and the second shielded section transducer 8 upstream and downstream of the shielded fuel unloading system pipe fitting 6, all receive the characteristic sound waves of the passing fuel sphere. Figure 8 The working condition shown (1) is the normal working condition without ball jamming.

[0055] like Figure 9 As shown, the first unshielded section transducer 2 and the second unshielded section transducer 4 are located upstream and downstream of the unshielded section fuel unloading system pipe fitting 3. The first shielded section transducer 7 upstream of the shielded section fuel unloading system pipe fitting 6 receives the characteristic sound wave of the fuel ball passing through, while the second shielded section transducer 8 does not receive the characteristic sound wave. Figure 9 The working condition shown (2) is the ball jamming condition at 6 points of the pipeline fittings of the fuel unloading system in the shield section.

[0056] like Figure 10 As shown, the first unshielded section transducer 2 and the second unshielded section transducer 4 upstream and downstream of the unshielded section fuel unloading system pipe fitting 3 both received the characteristic sound waves of the fuel ball passing through. The first shielded section transducer 7 and the second shielded section transducer 8 upstream and downstream of the shielded section fuel unloading system pipe fitting 6 did not receive the characteristic sound waves. Figure 10 The working condition shown (3) is the ball jamming condition between the pipeline fitting 3 of the unshielded section fuel unloading system and the pipeline fitting 6 of the shielded section fuel unloading system.

[0057] like Figure 11 As shown, the first unshielded section transducer 2 upstream of the unshielded section fuel unloading system pipe fitting 3 receives the characteristic sound wave of the fuel ball passing through. The second unshielded section transducer 4 and the first shielded section transducers 7 and second shielded section transducers 8 upstream and downstream of the shielded section fuel unloading system pipe fitting 6 do not receive the characteristic sound wave. Figure 11 The working condition shown (4) is the ball jamming condition at 3 points in the pipeline fittings of the fuel unloading system in the non-shielded section.

[0058] like Figure 12 As shown, the first unshielded section transducer 2 and the second unshielded section transducer 4 upstream and downstream of the unshielded section fuel unloading system pipeline fitting 3 receive acoustic signals normally. However, the time-domain signals received by the first shielded section transducer 7 and the second shielded section transducer 8 upstream of the shielded section fuel unloading system pipeline fitting 6 become sharper and steeper, with increased high-frequency components and abruptly increased amplitude response. Figure 12 The working condition shown (5) is the working condition of 6 broken balls in the pipeline of the fuel unloading system in the shield section. The size of the broken balls can be predicted by signal characteristics. Before formal monitoring, the sound signals of different broken ball sizes under normal and abnormal working conditions are measured. Experienced staff members are trained on sound signals for a long time to determine under what characteristics there are broken balls and the state of broken balls. The characteristics can be frequency and / or amplitude, or other characteristics or combinations.

[0059] It should be understood that the above description is for illustrative purposes and not for limitation. Many embodiments and applications beyond the provided examples will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of this teaching should not be determined by reference to the above description, but rather by reference to the foregoing claims and the full scope of their equivalents. For purposes of completeness, all articles and references, including patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the foregoing claims is not intended as a waiver of that subject matter, nor should it be construed as an indication that the applicant has not considered that subject matter as part of the disclosed inventive subject matter.

Claims

1. A health monitoring system for the ball-shaped pipeline of an HTR-PM fuel unloading system, characterized in that, It includes a first unshielded section transducer (2), a second unshielded section transducer (4), a first shielded section transducer (7), a second shielded section transducer (8), and a multi-channel acoustic emission detector (9). The first unshielded section transducer (2), the second unshielded section transducer (4), the first shielded section transducer (7), and the second shielded section transducer (8) are electrically connected to the multi-channel acoustic emission detector (9). The first unshielded section transducer (2) and the second unshielded section transducer (4) are respectively fixed upstream and downstream of the unshielded section fuel unloading system pipeline fitting (3); The first shielded section transducer (7) and the second shielded section transducer (8) are fixed upstream and downstream of the fuel unloading system pipeline fitting (6), respectively.

2. The HTR-PM fuel unloading system ball-type pipeline health monitoring system according to claim 1, characterized in that, The first unshielded section transducer (2), the second unshielded section transducer (4), the first shielded section transducer (7), and the second shielded section transducer (8) have the same structure.

3. The HTR-PM fuel unloading system ball-type pipeline health monitoring system according to claim 1, characterized in that, The first shielded section transducer (7) and the second shielded section transducer (8) are sleeve structures.

4. A health monitoring system for the ball-shaped pipeline of an HTR-PM fuel unloading system according to claim 1 or 3, characterized in that, The first shielded section transducer (7) includes a piezoelectric crystal portion (7-1), a sleeve portion (7-2), and a waveguide rod portion (7-3). The piezoelectric crystal portion (7-1) of the first shielded section transducer is in contact with the waveguide rod portion (7-3) of the first shielded section transducer, but not with the sleeve portion (7-2). The waveguide rod portion (7-3) of the first shielded section transducer is disposed inside the sleeve portion (7-2) of the first shielded section transducer.

5. The HTR-PM fuel unloading system ball-type pipeline health monitoring system according to claim 4, characterized in that, The sleeve portion (7-2) and waveguide portion (7-3) of the first shielded section transducer are filled with sound-absorbing material.

6. The HTR-PM fuel unloading system ball-type pipeline health monitoring system according to claim 1, characterized in that, The first unshielded section transducer (2), the second unshielded section transducer (4), the first shielded section transducer (7), and the second shielded section transducer (8) are connected to the same multi-channel acoustic emission detector (9) via connecting lines.

7. The HTR-PM fuel unloading system ball-type pipeline health monitoring system according to claim 1, characterized in that, The first unshielded section transducer (2), the second unshielded section transducer (4), the first shielded section transducer (7), and the second shielded section transducer (8) are all welded to the outer wall of the fuel unloading system pipeline (1).

8. A monitoring method for a health monitoring system of a ball-shaped pipeline in an HTR-PM fuel unloading system according to claim 1, characterized in that, Includes the following steps: During the process of the fuel ball rolling from top to bottom in the fuel unloading system pipeline (1), the first unshielded section transducer (2), the second unshielded section transducer (4), the first shielded section transducer (7), and the second shielded section transducer (8) collect sound signals. After the sound signals are calibrated by the multi-channel acoustic emission detector (9) to shield the interference waveform, the characteristic waveforms collected by each transducer are obtained. Based on whether the first unshielded section transducer (2), the second unshielded section transducer (4), the first shielded section transducer (7), and the second shielded section transducer (8) collect characteristic waveforms, and the collected characteristic waveforms, it is determined whether the ball is stuck or broken. If the ball is stuck, the position of the stuck ball is determined.

9. A monitoring method according to claim 8, characterized in that, By comparing and analyzing the waveform characteristics of each transducer, the size of the fuel pellet fragments can be determined.

10. A monitoring method according to claim 9, characterized in that, The waveform characteristics are frequency and / or amplitude.

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