WO2024087361A1

WO2024087361A1 - Health monitoring system and method for sphere pipeline of htr-pm fuel unloading system

Info

Publication number: WO2024087361A1
Application number: PCT/CN2022/140456
Authority: WO
Inventors: 赵阳; 王飞; 韩传高; 马晓珑; 张寅�; 张赓; 汪宁宁; 朱芮颍; 徐安; 朱煜; 贾晶晶; 孙海漩; 李铮; 毕凌云; 马刚; 余淑梅
Original assignee: 西安热工研究院有限公司
Priority date: 2022-10-28
Filing date: 2022-12-20
Publication date: 2024-05-02
Also published as: CN116052914A

Abstract

A health monitoring system and method for a sphere pipeline of an HTR-PM fuel unloading system. The monitoring system comprises a first non-shielding section transducer, a second non-shielding section transducer, a first shielding section transducer, a second shielding section transducer, and a multi-channel acoustic emission detector; the first non-shielding section transducer, the second non-shielding section transducer, the first shielding section transducer, and the second shielding section transducer are electrically connected to the multi-channel acoustic emission detector; the first non-shielding section transducer and the second non-shielding section transducer are respectively fixed on the upstream and downstream of a non-shielding section fuel unloading system pipeline fitting; and the first shielding section transducer and the second shielding section transducer are respectively fixed on the upstream and downstream of a fuel unloading system pipeline fitting. The monitoring system can continuously monitor the state of fuel spheres in a sphere pipeline of a fuel loading and unloading system for a long time, and can track and position the flow track of the fuel spheres.

Description

A ball pipeline health monitoring system and method for HTR-PM fuel unloading system

Technical Field

The present invention belongs to the technical field of pipeline health monitoring systems, and in particular relates to a ball pipeline health monitoring system and method for an HTR-PM fuel unloading system.

Background technique

The pebble bed high temperature gas-cooled reactor (HTR-PM) uses helium, which is chemically inert and has good thermal properties, as a coolant, all-ceramic coated particles as fuel balls, and high temperature resistant graphite as a moderator and core structural material. The number of fuel balls in a single reactor can reach hundreds of thousands, and the diameter of the fuel balls is about 60 mm. The fuel balls are generally continuously loaded into the core from the top of the core, and the fuel loading and unloading system realizes the functions of fuel ball reactive unloading and fuel ball circulation. Under balanced conditions, it can realize the rapid circulation of 12,000 core fuel balls/day/pile and the sorting of broken balls with a diameter of less than or equal to 56.5 mm, and the counting rate and sorting accuracy must reach 99.99%. In the event of fuel ball jamming or ball breakage, special equipment can be used at the disassembly end to clean the jammed balls. Therefore, the fuel unloading system is an important component system of the HTR-PM. Quickly obtaining the broken ball status and the jammed ball position can improve the system stability.

High temperature gas cooled reactors currently use ball passers to detect the passability of fuel balls. When the fuel ball passes through the ball passer at a fixed position, the impedance of the equilibrium state will be affected based on the eddy current principle. When the set threshold is exceeded, the ball passer determines that the fuel ball has passed this position. However, the ball path section of the fuel loading and unloading system is long, and the limited ball passer cannot accurately determine the position of the stuck ball. In addition, the eddy current impedance value will be affected by the temperature of the medium in the pipeline, and the accuracy and stability of the ball passing are low.

Summary of the invention

To solve the above problems, the present disclosure provides a HTR-PM fuel unloading system ball pipeline health monitoring system and method, which is used to monitor the status of fuel balls in the ball pipeline of the HTR-PM fuel unloading system in real time, and improve the accuracy and stability of the positioning of the fuel balls in the ball pipeline.

To achieve the above-mentioned objectives, the present disclosure proposes a HTR-PM fuel unloading system ball pipeline health monitoring system, including a first unshielded segment transducer, a second unshielded segment transducer, a first shielded segment transducer, a second shielded segment transducer and a multi-channel acoustic emission detector, wherein the first unshielded segment transducer, the second unshielded segment transducer, the first shielded segment transducer and the second shielded segment transducer are electrically connected to the multi-channel acoustic emission detector; the first unshielded segment transducer and the second unshielded segment transducer are respectively fixed upstream and downstream of the unshielded segment fuel unloading system pipeline fittings; the first shielded segment transducer and the second shielded segment transducer are respectively fixed upstream and downstream of the fuel unloading system pipeline fittings.

Furthermore, the first non-shielded segment transducer and the second non-shielded segment transducer, the first shielded segment transducer and the second shielded segment transducer have the same structure.

Furthermore, the first shielding segment transducer and the second shielding segment transducer are sleeve structures.

Furthermore, the first shielding segment transducer includes a piezoelectric chip part of the first shielding segment transducer, a sleeve part of the first shielding segment transducer and a waveguide rod part of the first shielding segment transducer, the piezoelectric chip part of the first shielding segment transducer is in contact with the waveguide rod part of the first shielding segment transducer and is not in contact with the sleeve part of the first shielding segment transducer; the waveguide rod part of the first shielding segment transducer is arranged in the sleeve part of the first shielding segment transducer.

Furthermore, the waveguide sleeve and the interior of the waveguide are filled with sound absorbing materials.

Furthermore, the first non-shielded segment transducer, the second non-shielded segment transducer, the first shielded segment transducer and the second shielded segment transducer are connected to the same multi-channel acoustic emission detector through connecting lines.

Furthermore, the first non-shielded segment transducer, the second non-shielded segment transducer, the first shielded segment transducer and the second shielded segment transducer are all welded to the outer wall of the fuel unloading system pipeline.

Based on the above-mentioned method for monitoring the health monitoring system of the ball pipeline of the HTR-PM fuel unloading system, the following steps are included:

During the rolling process from top to bottom in the pipeline of the fuel unloading system, the first non-shielded segment transducer, the second non-shielded segment transducer, the first shielded segment transducer and the second shielded segment transducer are connected to collect sound signals. After the sound signals are adjusted by the multi-channel acoustic emission detector to shield the interference waveform, the characteristic waveform collected by each transducer is obtained. According to whether the first non-shielded segment transducer, the second non-shielded segment transducer, the first shielded segment transducer and the second shielded segment transducer collect the characteristic waveform, and the collected characteristic waveform, it is judged whether the ball is stuck and whether the ball is broken. If the ball is stuck, the position of the stuck ball is judged.

Furthermore, the size of the fuel ball fragments can be determined by comparing and analyzing the waveform characteristics of each transducer.

Furthermore, the waveform characteristic is frequency and/or amplitude.

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

The present disclosure provides a HTR-PM fuel unloading system ball path pipeline health monitoring system, which can monitor the state of the fuel balls in the ball path pipeline of the fuel loading and unloading system for a long time, and can track and locate the flow trajectory of the fuel balls. When the fuel balls are in normal working conditions, that is, there is no broken ball or stuck ball, the fuel balls collide with the inner wall of the fuel loading and unloading pipeline, and the time domain acoustic signal collected by the transducer is almost a constant. The spectrum and amplitude response of the acoustic signal are a certain fixed threshold. If there is a broken ball or stuck ball working condition, the time domain acoustic signal will change and deviate from the normal threshold, and the acoustic signal received by the transducer is not affected by the temperature of the medium in the pipeline. Therefore, the position of the fuel ball can be judged by the signal received by the transducer arranged at different positions in the pipeline, and it can be judged whether the broken ball and stuck ball working conditions occur.

Furthermore, transducers are reasonably arranged on the ball path pipeline of the fuel loading and unloading system, and the acoustic emission signals under normal operating conditions are collected multiple times, and machine learning or manual statistics are carried out. The thresholds of the frequency spectrum and amplitude response of each channel under normal operating conditions are limited to a certain range. When a ball is stuck, the transducer downstream of the stuck ball position cannot receive the acoustic emission signal normally, triggering a threshold alarm. The approximate range of the stuck ball pipe section can be determined through the locations of the alarming and non-alarming transducers.

Furthermore, the fuel ball rolls in the tube section between the two transducers, and the trajectory of the fuel ball movement is determined by parameters such as the response duration and amplitude of the sound time domain signal of the transducer on one side.

Furthermore, when ball breakage occurs, the amplitude response of the acoustic emission signal received by the transducer closest to the ball breakage location will be much greater than the amplitude under normal conditions, which will also trigger the threshold alarm of the transducer at that location. The staff can determine the location where ball breakage and accumulation may occur based on the location of the alarm transducer.

Furthermore, when a fuel ball breakage condition occurs, the approximate size of the fuel ball breakage can be determined through comprehensive analysis of signal characteristics.

The present disclosure proposes a health monitoring method for a ball pipeline of an HTR-PM fuel unloading system. A transducer is used to collect sound signals. Whether each transducer can collect the sound signal and the characteristics of the collected sound signal can be used to continuously monitor the state of the fuel balls in the ball pipeline of the fuel loading and unloading system for a long time, and the flow trajectory of the fuel balls can be tracked and located, and it can be determined whether the fuel balls are in normal working conditions.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a perspective view of an acoustic emission positioning system for fuel balls in a HTR-PM fuel unloading pipeline;

FIG2 is a front view of an acoustic emission positioning system for fuel balls in a HTR-PM fuel unloading pipeline;

FIG3 is a left view of an acoustic emission positioning system for fuel balls in a HTR-PM fuel unloading pipeline;

FIG4 is a top view of an acoustic emission positioning system for fuel balls in a HTR-PM fuel unloading pipeline;

FIG5 is a perspective view of a shielded section waveguide rod transducer;

FIG6 is a front view of the shielded section waveguide rod transducer;

FIG7 is a left view of the shielded section waveguide rod transducer;

FIG8 is a waveform diagram of an embodiment of a detection waveform of working condition (1);

FIG9 is a waveform diagram of an embodiment of a detection waveform of working condition (2);

FIG10 is a waveform diagram of an embodiment of a detection waveform of working condition (3);

FIG11 is a waveform diagram of an embodiment of a detection waveform of working condition (4);

FIG. 12 is a waveform diagram of an embodiment of a detection waveform of working condition (5).

Description of reference numerals:

1. Fuel unloading system pipeline; 2. First non-shielded section transducer; 3. Non-shielded section fuel unloading system pipeline fittings; 4. Second non-shielded section transducer; 5. Lead shielding of fuel unloading system pipeline; 6. Shielded section fuel unloading system pipeline fittings; 7. First shielded section transducer; 8. Second shielded section transducer; 9. Multi-channel acoustic emission detector; 10. Connecting line between transducer and acoustic emission detector; 7-1. Piezoelectric chip part of the first shielded section transducer; 7-2. Sleeve part of the first shielded section transducer; 7-3. Waveguide rod part of the first shielded section transducer; 8-1. Piezoelectric chip part of the second shielded section transducer; 8-2. Sleeve part of the second shielded section transducer; 8-3. Waveguide rod part of the second shielded section transducer.

Detailed ways

The present disclosure is described in detail below with reference to the accompanying drawings and specific embodiments.

In order to enable those skilled in the art to better understand the technical solutions in the present disclosure, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in the field without making creative work should fall within the scope of protection of the present disclosure. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by technicians in the technical field of the present disclosure. The terms used in this specification are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure. The term "and/or" used herein includes any and all combinations of one or more related listed items.

It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention. The lead shielding and lead-free shielding pipe segment components of the fuel unloading system are used as examples for illustration.

Example 1

Referring to Figure 1, a HTR-PM fuel unloading system ball pipeline health monitoring system includes a fuel unloading system pipeline 1, a first non-shielded section transducer 2, a non-shielded section fuel unloading system pipeline fitting 3, a second non-shielded section transducer 4, a fuel unloading system pipeline lead shield 5, a shielded section fuel unloading system pipeline fitting 6, a first shielded section transducer 7, a second shielded section transducer 8, a multi-channel acoustic emission detector 9, and a connecting line 10 between the transducer and the acoustic emission detector.

As shown in Figure 1, the fuel unloading system pipeline 1 includes four straight pipes, three elbows, non-shielded fuel unloading system pipeline fittings 3 and shielded fuel unloading system pipeline fittings 6. The three elbows connect the four straight pipes in sequence to form the fuel unloading system pipeline 1. The fuel unloading system pipeline 1 is divided into a non-shielded fuel unloading system pipeline and a shielded fuel unloading system pipeline. The non-shielded fuel unloading system pipeline is provided with non-shielded fuel unloading system pipeline fittings 3 outside the non-shielded fuel unloading system pipeline, and the shielded fuel unloading system pipeline is provided with shielded fuel unloading system pipeline fittings 6 outside the shielded fuel unloading system pipeline.

The straight pipes, elbows, non-shielded fuel unloading system pipe fittings 3, shielded fuel unloading system pipe fittings 6 and the externally coated fuel unloading system pipe lead shield 5 in the fuel unloading system pipe may have the risk of ball jamming, and the fuel unloading system pipe lead shield 5 is full of lead sand with radiation shielding effect, which affects the arrangement of the acoustic emission transducer. Combined with the on-site environment, the fuel unloading system pipe 1 is divided into two working conditions: shielded section and non-shielded section, and transducers are installed for signal acquisition.

As shown in Figures 1 to 4, the first non-shielded section transducer 2 and the second non-shielded section transducer 4 are respectively arranged upstream and downstream of the non-shielded section fuel unloading system pipeline fitting 3 where the fuel balls may be stuck, and are fixed to the outer wall of the fuel unloading system pipeline 1 by welding or other means.

As shown in Figures 1 to 4, the lead shielding 5 of the fuel unloading system pipeline is coated on the outer side of the shielding section fuel unloading system pipeline fitting 6, and is filled with lead sand for radiation shielding. Through holes passing through the first waveguide rod sleeve 7-2 and the second waveguide rod sleeve 8-2 are respectively arranged corresponding to the positions of the first shielding section transducer 7 and the second shielding section transducer 8.

As shown in Figures 1 to 4, the first shielding segment transducer 7 and the second shielding segment transducer 8 are respectively arranged upstream and downstream of the shielding segment fuel unloading system pipeline fitting 6 where the fuel ball may be stuck, and the waveguide rod sleeve 7-2 and the waveguide rod sleeve 8-2 pass through the through holes reserved on the lead shielding 5 of the fuel unloading system pipeline, and are fixed to the outer wall of the fuel unloading system pipeline 1 by welding or the like.

As shown in Fig. 5 and Fig. 6, the first shielding segment transducer 7 is a waveguide rod transducer with a sleeve structure, which is respectively composed of a piezoelectric chip portion 7-1 of the first shielding segment transducer, a sleeve portion 7-2 of the first shielding segment transducer and a waveguide rod portion 7-3 of the first shielding segment transducer. The piezoelectric chip portion 7-1 of the first shielding segment transducer is in direct contact with the waveguide rod portion 7-3 of the first shielding segment transducer and is not in contact with the sleeve portion 7-2 of the first shielding segment transducer. The waveguide rod portion 7-3 is not in contact with the sleeve portion 7-2 of the first shielding segment transducer.

As shown in Figures 5 and 6, the second shielding segment transducer 8 is respectively composed of the piezoelectric chip part 8-1, 2 of the second shielding segment transducer, the sleeve part 8-2 of the second shielding segment transducer and the waveguide rod part 8-3 of the second shielding segment transducer. The piezoelectric chip part 8-1 of the second shielding segment transducer is in direct contact with the waveguide rod part 8-3 of the second shielding segment transducer, and can be fixed and installed by bonding or welding according to site conditions, and does not contact with the sleeve part 8-2 of the second shielding segment transducer.

As shown in Figures 5 to 7, during the propagation of sound waves in the waveguide rod, in order to reduce the sound energy loss caused by the direct contact of the waveguide rod with the lead sand, the first shielding section transducer 7 and the second shielding section transducer 8 adopt a sleeve structure, and the waveguide rod 7-3 and the waveguide rod 8-3 are respectively inserted into the waveguide rod sleeve 7-2 and the waveguide rod sleeve 8-2, and the waveguide rod sleeve 7-2 and the waveguide rod sleeve 8-2 pass through the lead shield 5, and the influence of the lead sand on the sound energy should be isolated. The waveguide rod sleeve 7-2, the waveguide rod sleeve 8-2, the waveguide rod 7-3, and the waveguide rod 8-3 are fixedly installed on the outer wall of the fuel unloading system pipeline 1 by welding or the like, 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. Sound-absorbing material is filled between the waveguide sleeve 7-2 and the waveguide tube 7-3, and sound-absorbing material is filled inside the waveguide sleeve 8-2 and the waveguide tube 8-3. In addition to reducing the interference of clutter caused by sound waves propagating in the waveguide rod and reducing the loss of sound energy, the sound-absorbing material also plays a supporting role for the sleeve and the waveguide rod.

As shown in Figure 1, one end of the four connecting wires 10 is independently connected to the first non-shielded segment transducer 2, the second non-shielded segment transducer 4, the shielded segment transducer 7, and the second shielded segment transducer 8, and the other end is collectively connected to the multi-channel acoustic emission detector 9, which can simultaneously collect and monitor the signals received by multiple transducers.

Example 2

A method for monitoring the health of a ball pipeline of a HTR-PM fuel unloading system, based on the device for monitoring the health of a ball pipeline of a HTR-PM fuel unloading system of Example 1, comprises the following steps:

The fuel ball rolls from top to bottom in the fuel unloading system pipeline 1 under the action of gravity or other system atmosphere thrust. The first non-shielded segment transducer 2, the second non-shielded segment transducer 4, the first shielded segment transducer 7 and the second shielded segment transducer 8 collect sound signals. After the multi-channel acoustic emission detector 9 adjusts the shielding interference waveform, it is considered that the waveform collected by each channel is only the synchronous characteristic waveform when the fuel ball flows through the transducer. According to whether the first non-shielded segment transducer 2, the second non-shielded segment transducer 4, the first shielded segment transducer 7 and the second shielded segment transducer 8 collect characteristic waveforms, and whether the ball is stuck or broken, it is judged whether the ball is stuck or broken according to the collected characteristic waveforms. If the ball is stuck, the position of the stuck ball is judged:

When the fuel ball successfully passes through the non-shielded section fuel unloading system pipeline fitting 3 and the shielded section fuel unloading system pipeline fitting 6, the first non-shielded section transducer 2 and the second non-shielded section transducer 4 upstream and downstream of the non-shielded section fuel unloading system pipeline fitting 3, and the first shielded section transducer 7 and the second shielded section transducer 8 upstream and downstream of the shielded section fuel unloading system pipeline fitting 6 all receive the characteristic sound waves passed by the fuel ball. The operating condition (1) shown in Figure 8 is a normal operating condition without ball jamming.

As shown in Figure 9, the first non-shielded section transducer 2 and the second non-shielded section transducer 4 upstream and downstream of the non-shielded section fuel unloading system pipeline fitting 3, and the first shielded section transducer 7 upstream of the shielded section fuel unloading system pipeline fitting 6 receive the characteristic sound waves of the fuel ball passing through, and the second shielded section transducer 8 does not receive the characteristic sound waves. The operating condition (2) shown in Figure 9 is the ball stuck condition at the shielded section fuel unloading system pipeline fitting 6.

As shown in Figure 10, the first non-shielded section transducer 2 and the second non-shielded section transducer 4 upstream and downstream of the non-shielded section fuel unloading system pipeline fitting 3 both received the characteristic sound waves passing through the fuel ball, and the first shielded section transducer 7 and the second shielded section transducer 8 upstream and downstream of the shielded section fuel unloading system pipeline fitting 6 did not receive the characteristic sound waves. The operating condition (3) shown in Figure 10 is the ball stuck condition in the pipe section between the non-shielded section fuel unloading system pipeline fitting 3 and the shielded section fuel unloading system pipeline fitting 6.

As shown in Figure 11, the first non-shielded section transducer 2 upstream of the non-shielded section fuel unloading system pipeline fitting 3 receives the characteristic sound wave of the fuel ball passing through, the second non-shielded section transducer 4 and the first shielded section transducer 7 and the second shielded section transducer 8 upstream and downstream of the shielded section fuel unloading system pipeline fitting 6 do not receive the characteristic sound wave. The operating condition (4) shown in Figure 11 is the ball stuck condition at the non-shielded section fuel unloading system pipeline fitting 3.

As shown in FIG12 , the first non-shielded segment transducer 2 and the second non-shielded segment transducer 4 upstream and downstream of the non-shielded segment fuel unloading system pipeline fitting 3 receive acoustic wave signals normally, while the time domain signals received by the first shielded segment transducer 7 and the second shielded segment transducer 8 upstream of the shielded segment fuel unloading system pipeline fitting 6 become sharp and steep, with an increase in high-frequency components and a sudden increase in amplitude response. The operating condition (5) shown in FIG12 is the ball breaking condition at the shielded segment fuel unloading system pipeline fitting 6, and the ball breaking size can be predicted by signal characteristics. Before formal monitoring, the acoustic signals of different ball breaking sizes under normal and abnormal conditions are measured, and experienced staff are trained on acoustic signals for a long time to determine under what characteristics ball breaking exists and the state of the ball breaking. The characteristics can be frequency and/or amplitude, or other characteristics or combinations.

It should be understood that the above description is for illustration and not for limitation. Many embodiments and many applications beyond the examples provided will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of the present teachings should not be determined with reference to the above description, but rather with reference to the foregoing claims and the full scope of equivalents to which such claims are entitled. For the purpose of comprehensiveness, all articles and references, including disclosures of 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 to be a waiver of such subject matter, nor should it be considered that the applicant has not considered such subject matter to be part of the disclosed inventive subject matter.

Claims

A HTR-PM fuel unloading system ball pipeline health monitoring system, characterized in that it comprises a first unshielded segment transducer (2), a second unshielded segment transducer (4), a first shielded segment transducer (7), a second shielded segment transducer (8) and a multi-channel acoustic emission detector (9), wherein the first unshielded segment transducer (2), the second unshielded segment transducer (4), the first shielded segment transducer (7), the second shielded segment transducer (8) are electrically connected to the multi-channel acoustic emission detector (9);

The first non-shielded section transducer (2) and the second non-shielded section transducer (4) are respectively fixed upstream and downstream of the non-shielded section fuel unloading system pipeline fitting (3);

The first shielding segment transducer (7) and the second shielding segment transducer (8) are respectively fixed upstream and downstream of the fuel unloading system pipeline fitting (6).
According to claim 1, a HTR-PM fuel unloading system ball pipeline health monitoring system is characterized in that the first non-shielded segment transducer (2), the second non-shielded segment transducer (4), the first shielded segment transducer (7) and the second shielded segment transducer (8) have the same structure.
According to the HTR-PM fuel unloading system ball pipeline health monitoring system of claim 1, it is characterized in that the first shielding segment transducer (7) and the second shielding segment transducer (8) are sleeve structures.
According to a HTR-PM fuel unloading system ball pipeline health monitoring system according to claim 1 or 3, it is characterized in that the first shielding segment transducer (7) includes a piezoelectric chip part (7-1) of the first shielding segment transducer, a sleeve part (7-2) of the first shielding segment transducer and a waveguide rod part (7-3) of the first shielding segment transducer, the piezoelectric chip part (7-1) of the first shielding segment transducer is in contact with the waveguide rod part (7-3) of the first shielding segment transducer, and is not in contact with the sleeve part (7-2) of the first shielding segment transducer; the waveguide rod part (7-3) of the first shielding segment transducer is arranged in the sleeve part (7-2) of the first shielding segment transducer.
According to claim 4, a HTR-PM fuel unloading system ball pipeline health monitoring system is characterized in that the waveguide sleeve (7-2) and the waveguide (7-3) are filled with sound absorbing materials.
According to claim 1, a HTR-PM fuel unloading system ball pipeline health monitoring system is characterized in that the first unshielded segment transducer (2), the second unshielded segment transducer (4), the first shielded segment transducer (7) and the second shielded segment transducer (8) are connected to the same multi-channel acoustic emission detector (9) through a connecting line.
According to claim 1, a HTR-PM fuel unloading system ball pipeline health monitoring system is characterized in that the first non-shielded segment transducer (2), the second non-shielded segment transducer (4), the first shielded segment transducer (7) and the second shielded segment transducer (8) are all welded to the outer wall of the fuel unloading system pipeline (1).
A monitoring method for a ball pipeline health monitoring system of a HTR-PM fuel unloading system according to claim 1, characterized in that it comprises the following steps:

During the rolling process from top to bottom in the fuel unloading system pipeline (1), the first non-shielded segment transducer (2), the second non-shielded segment transducer (4), the first shielded segment transducer (7) and the second shielded segment transducer (8) are connected to collect sound signals. After the sound signals are adjusted by a multi-channel acoustic emission detector (9) to shield interference waveforms, characteristic waveforms collected by each transducer are obtained. According to whether the first non-shielded segment transducer (2), the second non-shielded segment transducer (4), the first shielded segment transducer (7) and the second shielded segment transducer (8) collect characteristic waveforms, and whether ball jamming and ball breakage occur, it is determined based on the collected characteristic waveforms. If ball jamming occurs, the position of the jammed ball is determined.
A monitoring method according to claim 8, characterized in that the size of the fuel ball fragments is determined by comparing and analyzing the waveform characteristics of each transducer.
A monitoring method according to claim 9, characterized in that the waveform characteristics are frequency and/or amplitude.