Analysis method for failure reason of nuclear power rubber expansion joint
Through systematic on-site investigation and various testing methods, the causes of the failure of the rubber expansion joint of the nuclear power plant are analyzed, and the problem of lack of effective failure analysis in the existing technology is solved, and the effect of quickly finding the causes of failure and targeted optimization is achieved.
Patent Information
- Application Number
- CN202411760354.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-03
- Publication Date
- 2025-02-14
AI Technical Summary
The failure of rubber expansion joints in nuclear power plants has seriously affected the normal operation of the unit. The existing technology lacks effective failure analysis methods to find the root cause.
Through multiple steps such as on-site investigation, data collection, material identification, mechanical performance testing, fracture observation and aging test, the causes of rubber expansion joint failure are analyzed.
It can quickly find out the root cause of the failure of the rubber expansion joint, provide targeted optimization and rectification measures, and ensure that similar problems will not occur in the future.
Smart Images
Figure CN119438120A_ABST
Abstract
Description
Technical Field
[0001] The present application belongs to the technical field of failure cause analysis of rubber expansion joint components of nuclear power plants, and specifically relates to a method for analyzing the failure cause of nuclear power rubber expansion joints. Background Art
[0002] Rubber expansion joints are rubber products installed on container shells or pipelines to compensate for additional stress caused by temperature differences and mechanical vibrations. They are widely used in nuclear power plants because they transmit cooling water and other media internally and are components of important nuclear safety systems, so they have received widespread attention.
[0003] In recent years, rubber expansion joint failures have occurred in many nuclear power plants, seriously affecting the normal operation of the units. However, there is currently a lack of research on failure analysis of failed expansion joints to find out the root cause of expansion joint failure. Summary of the invention
[0004] In view of this, the present application is committed to providing a method for analyzing the causes of failure of nuclear power rubber expansion joints. By analyzing the causes of failure of rubber expansion joints based on the data of failed rubber expansion joints and multiple test results, the technical problem of nuclear power plants in the prior art being seriously affected by the normal operation of the units due to failure of rubber expansion joints is solved.
[0005] The present application provides a method for analyzing the failure causes of nuclear power rubber expansion joints, and the method for analyzing the failure causes of nuclear power rubber expansion joints includes: conducting on-site investigations and collecting information on failed rubber expansion joints; sampling the rubber expansion joints and conducting material identification tests to obtain material test results; sampling and preparing mechanical property test specimens according to the structure of the rubber expansion joints, and conducting mechanical property tests to obtain mechanical property test results; observing the failure fracture surface according to the morphology of the failed rubber expansion joints to obtain failure fracture observation results; sampling the rubber expansion joints and conducting accelerated aging tests or oxidation induction period tests to obtain aging test or oxidation induction period test results; analyzing the failure causes of the rubber expansion joints according to one or more of the information on the failed rubber expansion joints, material test results, mechanical property test results, failure fracture observation results, aging test or oxidation induction period test results.
[0006] In a specific embodiment of the present application, sampling is performed on the rubber expansion joint and a material identification test is performed to obtain material detection results, including: sampling is performed on the rubber expansion joint and a material identification test is performed on the inner and outer rubber layers of the rubber expansion joint to obtain material detection results.
[0007] In a specific embodiment of the present application, based on the morphology of the failed rubber expansion joint, a fracture observation is performed on the failed fracture to obtain the failure fracture observation result, including: based on the morphology of the failed rubber expansion joint, a fracture observation is performed using a stereo microscope or a scanning electron microscope to obtain the failure fracture observation result.
[0008] In a specific embodiment of the present application, the failure cause of the rubber expansion joint is analyzed based on one or more of the data of the failed rubber expansion joint, material test results, mechanical property test results, failure fracture observation results, aging test or oxidation induction period test results, including:
[0009] Based on the material test results and the data of the failed rubber expansion joint, if the test material in the material test results does not match the design material in the data of the failed rubber expansion joint, then the cause of failure is confirmed to be material mismatch; and / or,
[0010] Based on the mechanical properties test results and the data of the failed rubber expansion joint, if the mechanical properties test results do not meet the mechanical properties design requirements in the data of the failed rubber expansion joint, it is confirmed that the cause of failure is unqualified material; and / or,
[0011] According to the observation result of the failure fracture, if the observation result of the failure fracture shows that the fracture has obvious abnormality, it is confirmed that the cause of failure is a manufacturing process defect; and / or,
[0012] According to the results of the aging test or the oxidation induction period test, if the aging test or the oxidation induction period test result is that the aging test fails, or the oxidation induction period time is shorter than the preset time, it is confirmed that the cause of failure is material aging; and / or,
[0013] According to the material test results, if the tested material in the material test results does not match the designed material, it is confirmed that the cause of failure is material mismatch.
[0014] In a specific embodiment of the present application, based on the material test results and the information of the failed rubber expansion joint, if the test material in the material test results does not match the designed material in the information of the failed rubber expansion joint, then the cause of the failure is confirmed to be the material inconsistency, including: if the information of the failed rubber expansion joint includes the design information and factory inspection report of the rubber expansion joint, the material test results are compared with the design information and the factory inspection report, if the material test results do not match the designed material in the design information and the factory inspection report, then the cause of the failure is confirmed to be the material inconsistency.
[0015] In a specific embodiment of the present application, based on the mechanical property test results and the information of the failed rubber expansion joint, if the mechanical property test results do not meet the mechanical property design requirements in the information of the failed rubber expansion joint, then the cause of the failure is confirmed to be unqualified material, including: if the information of the failed rubber expansion joint includes the design information and factory inspection report of the rubber expansion joint, the mechanical property test results are compared with the mechanical property design requirements in the design information and the factory inspection report, if the comparison result is that the mechanical property test results are unqualified, then the cause of the failure is confirmed to be unqualified material.
[0016] In a specific embodiment of the present application, based on the failure fracture observation result, if the failure fracture observation result is that there is an obvious abnormality in the fracture, then the cause of the failure is confirmed to be a manufacturing process defect, including: based on the failure fracture observation result, comparing the failure fracture observation result with the morphology of a comparison part, if the comparison result is that there is an obvious abnormality in the fracture, then the cause of the failure is confirmed to be a manufacturing process defect.
[0017] In a specific embodiment of the present application, the method for analyzing the failure cause of the nuclear power rubber expansion joint also includes: if the above tests are all qualified, then analyzing the failure cause of the rubber expansion joint in combination with the failure site, installation process and comprehensive stress.
[0018] In a specific embodiment of the present application, the information of the failed rubber expansion joint includes one or more of design drawings, production and manufacturing, factory inspection, storage and packaging, installation and commissioning, modification and transformation, and the same or similar historical failure events of nuclear power plants at home and abroad.
[0019] In a specific embodiment of the present application, the accelerated aging test is an air accelerated aging test; and / or, the oxidation induction period test temperature is selected to be 200° C.; and / or, the mechanical property test includes material hardness, tensile and tear strength tests.
[0020] The beneficial effect of the technical solution of the present application is that by performing failure analysis on the failed rubber expansion joint, the root cause of the failure of the expansion joint can be found out according to one or more of the data of the failed rubber expansion joint, material test results, mechanical property test results, failure fracture observation results, aging test or oxidation induction period test results, so that the cause of the failure of the rubber expansion joint can be quickly found, which is conducive to targeted optimization and rectification to ensure that similar problems will not occur in the future. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 Shown is a flow chart of a method for analyzing the failure causes of nuclear power rubber expansion joints provided in one embodiment of the present application. DETAILED DESCRIPTION
[0022] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.
[0023] At least one embodiment of the present application provides a method for analyzing the failure causes of nuclear power rubber expansion joints, referring to Figure 1 The method for analyzing the failure cause of the nuclear power rubber expansion joint includes the following steps.
[0024] S1: Conduct on-site investigation and collect data on failed rubber expansion joints.
[0025] S2: Take samples from the rubber expansion joint and conduct material identification tests to obtain material test results.
[0026] S2.1: Take samples from the rubber expansion joint and perform material identification tests on the inner and outer rubber layers of the rubber expansion joint to obtain material test results.
[0027] For example, a Fourier infrared spectrometer can be used to perform material identification tests. The materials of the rubber expansion joint include but are not limited to EPDM or nitrile rubber.
[0028] S3: According to the structure of the rubber expansion joint, sample and prepare mechanical property test specimens, and conduct mechanical property tests to obtain mechanical property test results.
[0029] In at least one embodiment of the present application, the mechanical property test includes material hardness, tensile and tear strength tests.
[0030] S4: According to the morphology of the failed rubber expansion joint, the failure fracture is observed to obtain the failure fracture observation results.
[0031] S4.1: Based on the morphology of the failed rubber expansion joint, use a stereo microscope or a scanning electron microscope to observe the fracture surface to obtain the failure fracture observation results.
[0032] S5: Take samples from the rubber expansion joint and conduct accelerated aging test or oxidation induction period test to obtain aging test or oxidation induction period test results.
[0033] In at least one embodiment of the present application, the accelerated aging test is an air accelerated aging test.
[0034] In at least one embodiment of the present application, the oxidation induction period test temperature is selected to be 200°C.
[0035] S6: Analyze the failure cause of the rubber expansion joint based on one or more of the failed rubber expansion joint’s data, material test results, mechanical property test results, failure fracture observation results, aging test or oxidation induction period test results.
[0036] According to the technical solution provided in the embodiment of the present application, by performing failure analysis on the failed rubber expansion joint, the root cause of the failure of the expansion joint can be found out based on one or more of the information of the failed rubber expansion joint, material test results, mechanical property test results, failure fracture observation results, aging test or oxidation induction period test results. This can quickly identify the cause of the failure of the rubber expansion joint, which is conducive to targeted optimization and rectification to ensure that similar problems do not occur in the future.
[0037] In at least one embodiment of the present application, one or more of S6.1 to S6.5 is a specific implementation of the above S6.
[0038] S6.1: Based on the material test results and the data of the failed rubber expansion joint, if the test material in the material test results does not match the design material in the data of the failed rubber expansion joint, the cause of the failure is confirmed to be material mismatch.
[0039] S6.1.1: If the data of the failed rubber expansion joint include the design data and factory inspection report of the rubber expansion joint, compare the material test results with the design data and factory inspection report. If the material test results do not match the design material in the design data and factory inspection report, the cause of failure is confirmed to be material mismatch.
[0040] S6.2: Based on the mechanical properties test results and the data of the failed rubber expansion joint, if the mechanical properties test results do not meet the mechanical properties design requirements in the data of the failed rubber expansion joint, it is confirmed that the cause of failure is unqualified material.
[0041] S6.2.1: If the data of the failed rubber expansion joint include the design data and factory inspection report of the rubber expansion joint, compare the mechanical property test results with the mechanical property design requirements in the design data and factory inspection report. If the comparison result shows that the mechanical property test results are unqualified, it is confirmed that the cause of failure is unqualified material.
[0042] S6.3: Based on the failure fracture observation results, if the failure fracture observation results show that the fracture has obvious abnormalities, it is confirmed that the cause of failure is a manufacturing process defect.
[0043] S6.3.1: Based on the failure fracture observation results, compare the failure fracture observation results with the morphology of the reference part. If the comparison result shows that the fracture has obvious abnormalities, it is confirmed that the cause of failure is a manufacturing process defect.
[0044] S6.4: Based on the results of the aging test or the oxidation induction period test, if the results of the aging test or the oxidation induction period test are that the aging test fails, or the oxidation induction period is shorter than the preset time, it is confirmed that the cause of failure is material aging.
[0045] The preset duration can be set according to actual needs, for example, 1 minute to 5 minutes, and for example, 2 minutes.
[0046] S6.5: Based on the material test results, if the material tested does not match the designed material, the cause of the failure is confirmed to be material mismatch.
[0047] In at least one embodiment of the present application, the method for analyzing the failure cause of the nuclear power rubber expansion joint also includes S7.
[0048] S7: All the above tests are qualified. The failure cause of the rubber expansion joint is analyzed based on the failure site, installation process and comprehensive stress.
[0049] For example, the cause of failure analysis may be material fatigue or other causes.
[0050] In at least one embodiment of the present application, the comprehensive force analysis includes simple force analysis and simulation force analysis.
[0051] In at least one embodiment of the present application, the data of the failed rubber expansion joint includes design drawings, manufacturing, factory inspection, storage packaging, installation and commissioning, and modification and transformation, etc. In this way, the data of the failed rubber expansion joint can be used to quickly understand the failure form of the rubber expansion joint.
[0052] In at least one embodiment of the present application, the data of the failed rubber expansion joint also includes the same or similar historical failure events of nuclear power plants at home and abroad. In this way, the failure cause of the nuclear power rubber expansion joint can be found more quickly by analyzing the similarities and differences between the same or similar historical failure events of nuclear power plants at home and abroad and the current failure event.
[0053] In the above embodiments of the present application, a method for rapid analysis of the failure causes of nuclear power rubber expansion joints is proposed, and through practice, it can guide nuclear power plants to quickly find out the failure causes of expansion joints and propose reasonable improvement measures.
[0054] The failure analysis method of the rubber material of the present application will be described in detail below in combination with embodiments, comparative examples and experimental data.
[0055] Embodiment 1: The outer rubber of the rubber expansion joint is EPDM rubber, and the inner rubber is nitrile rubber.
[0056] The method for analyzing the failure cause of the nuclear power rubber expansion joint includes: performing the above-mentioned S1 to S6 on the failed rubber expansion joint, and finding through the S4 result that there is only one long crack on the surface of the expansion joint, thus confirming that the rubber expansion joint is damaged by external force and causes failure.
[0057] Embodiment 2: The outer rubber and the inner rubber of the rubber expansion joint are both EPDM rubber.
[0058] The method for analyzing the failure cause of the nuclear power rubber expansion joint includes: implementing the above S1 to S6 on the failed rubber expansion joint, and finding through S1 that the rubber expansion joint has been used for 2 months, and through S3 results that the tensile properties of the rubber are lower than the design requirements, then it is confirmed that the failure is caused by unqualified materials of the rubber expansion joint.
[0059] Embodiment 3: The outer rubber and the inner rubber of the rubber expansion joint are both EPDM rubber.
[0060] The method for analyzing the failure cause of the nuclear power rubber expansion joint includes: implementing the above S1 to S6 on the failed rubber expansion joint, and through the S1 result it is found that the rubber expansion joint has been in use for 1.5 years, and through the S4 result it is found that the fabric position of the rubber expansion joint is different from the position of the comparison part, and the cross-sectional rubber area of the failed rubber expansion joint is too large, then it is confirmed that the failure is caused by unqualified manufacturing process of the rubber expansion joint.
[0061] Embodiment 4: The outer rubber and the inner rubber of the rubber expansion joint are both EPDM rubber.
[0062] The method for analyzing the failure cause of the nuclear power rubber expansion joint includes: implementing the above S1 to S6 on the failed rubber expansion joint, and the result of S1 found that the rubber expansion joint has been in use for 3 years, and the result of S4 found that there are many small cracks on the surface of the rubber expansion joint, and the result of S5 found that the oxidation induction period of the rubber expansion joint is only 38 seconds, which confirms that the failure of the rubber expansion joint is caused by material aging.
[0063] It should be noted that the combination of the various technical features in the embodiments of the present application is not limited to the combination described in the embodiments of the present application or the combination described in the specific embodiments, and all technical features described in the present application can be freely combined or combined in any way unless there is a contradiction between them.
[0064] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.
Claims
1. A method for analyzing the failure causes of nuclear power rubber expansion joints, characterized in that: include: Conduct on-site investigation and collect data on failed rubber expansion joints; Take samples from rubber expansion joints and conduct material identification tests to obtain material test results; According to the structure of the rubber expansion joint, samples are taken to prepare mechanical properties test specimens, and mechanical properties tests are carried out to obtain mechanical properties test results; According to the morphology of the rubber expansion joint failure, the failure fracture is observed to obtain the failure fracture observation results; Take samples from the rubber expansion joint and conduct accelerated aging test or oxidation induction period test to obtain the aging test or oxidation induction period test results; Analyze the failure cause of the rubber expansion joint based on one or more of the failed rubber expansion joint's information, material test results, mechanical property test results, failure fracture observation results, aging test or oxidation induction period test results.
2. The method for analyzing the failure cause of a nuclear power rubber expansion joint according to claim 1, characterized in that: Take samples from rubber expansion joints and conduct material identification tests to obtain material test results, including: Take samples from the rubber expansion joint and conduct material identification tests on the inner and outer rubber layers of the rubber expansion joint to obtain material test results.
3. The method for analyzing the failure cause of a nuclear power rubber expansion joint according to claim 1, characterized in that: According to the morphology of the rubber expansion joint failure, the failure fracture is observed to obtain the failure fracture observation results, including: According to the morphology of the failed rubber expansion joint, the fracture surface is observed using a stereo microscope or a scanning electron microscope to obtain the failure fracture observation results.
4. The method for analyzing the failure cause of a nuclear power rubber expansion joint according to claim 1, characterized in that: Analyze the failure cause of the rubber expansion joint based on one or more of the failed rubber expansion joint data, material test results, mechanical property test results, failure fracture observation results, aging test or oxidation induction period test results, including: Based on the material test results and the data of the failed rubber expansion joint, if the test material in the material test results does not match the design material in the data of the failed rubber expansion joint, then the cause of failure is confirmed to be material mismatch; and / or, Based on the mechanical properties test results and the data of the failed rubber expansion joint, if the mechanical properties test results do not meet the mechanical properties design requirements in the data of the failed rubber expansion joint, it is confirmed that the cause of failure is unqualified material; and / or, According to the observation result of the failure fracture, if the observation result of the failure fracture shows that the fracture has obvious abnormality, it is confirmed that the cause of failure is a manufacturing process defect; and / or, According to the results of the aging test or the oxidation induction period test, if the aging test or the oxidation induction period test result is that the aging test fails, or the oxidation induction period time is shorter than the preset time, it is confirmed that the cause of failure is material aging; and / or, According to the material test results, if the tested material in the material test results does not match the designed material, it is confirmed that the cause of failure is material mismatch.
5. The method for analyzing the failure cause of a nuclear power rubber expansion joint according to claim 4, characterized in that: According to the material test results and the data of the failed rubber expansion joint, if the test material in the material test results does not match the design material in the data of the failed rubber expansion joint, then the cause of failure is confirmed to be material inconsistency, including: If the information of the failed rubber expansion joint includes the design information and factory inspection report of the rubber expansion joint, compare the material test results with the design information and factory inspection report. If the material test results do not match the design material in the design information and factory inspection report, then the cause of failure is confirmed to be material mismatch.
6. The method for analyzing the failure cause of a nuclear power rubber expansion joint according to claim 4 is characterized in that: According to the mechanical properties test results and the data of the failed rubber expansion joint, if the mechanical properties test results do not meet the mechanical properties design requirements in the data of the failed rubber expansion joint, it is confirmed that the cause of failure is unqualified material, including: If the information of the failed rubber expansion joint includes the design information and factory inspection report of the rubber expansion joint, compare the mechanical properties test results with the mechanical properties design requirements in the design information and factory inspection report. If the comparison result is that the mechanical properties test results are unqualified, it is confirmed that the cause of failure is unqualified material.
7. The method for analyzing the failure causes of nuclear power rubber expansion joints according to claim 4, characterized in that: According to the observation results of the failure fracture, if the observation results of the failure fracture show that the fracture has obvious abnormal phenomena, it is confirmed that the cause of failure is a manufacturing process defect, including: According to the observation results of the failure fracture, the failure fracture observation results are compared with the morphology of the reference part. If the comparison result shows that the fracture has obvious abnormality, it is confirmed that the cause of failure is a manufacturing process defect.
8. The method for analyzing the failure causes of nuclear power rubber expansion joints according to claim 1, characterized in that: Also includes: If all the above tests are qualified, the failure cause of the rubber expansion joint is analyzed in combination with the failure site, installation process and comprehensive stress.
9. A method for analyzing failure causes of nuclear power rubber expansion joints according to any one of claims 1 to 8, characterized in that: The data of failed rubber expansion joints include design drawings, production and manufacturing, factory inspection, storage and packaging, installation and commissioning, modification and transformation, and one or more of the same or similar historical failure events in domestic and foreign nuclear power plants.
10. A method for analyzing failure causes of nuclear power rubber expansion joints according to any one of claims 1 to 8, characterized in that: The accelerated aging test is an air accelerated aging test; and / or, the oxidation induction period test temperature is selected to be 200° C.; and / or, the mechanical property test includes material hardness, tensile and tear strength tests.