Test method for simulating thermal aging of metal sealing ring

Abstract

The invention relates to a test method for simulating thermal aging of a metal sealing ring, the test method is carried out through a test device, and the test device comprises a test container, double sealing rings, a helium leak detector and a heating device; the test method comprises the following steps: measuring initial size parameters of the double sealing rings, wherein the size parameters comprise an inner diameter, an outer diameter and a wire diameter; installing the double sealing rings on the test container, and connecting a helium leak detector to a gap between the sealing rings of the double sealing rings; filling helium into the test container, and then placing the test container in a heating device for heating; when the temperature of the double sealing rings rises to the test temperature T DEG C, the temperature is maintained, the leakage rate is recorded through the helium leak detector, and the recording time is t; the test temperature T and the recording duration t are obtained through the Marson Muller formula LMP = T (C + log t), C is a constant, T is the test temperature, K and t are the recording duration, and H and LMP are acceleration characteristic parameters; and when the recording duration reaches t, ending the test.

Description

Technical Field

[0001] The invention relates to the technical field of sealing performance detection of sealing rings, and in particular to a test method for simulating thermal aging of metal sealing rings. Background Art

[0002] According to relevant national regulations, standards and design requirements, during the design phase, radioactive material transport containers must consider the impact of various aging factors on the performance of the transport container materials and components during the future life cycle to ensure that good safety performance can always be maintained. Spent fuel has a high heat release rate, which causes some parts of the spent fuel container to be in a high temperature environment. Long-term high temperature conditions will cause the performance of the components to deteriorate. The metal sealing ring is a key component to achieve the sealing function of the spent fuel container, so the impact of long-term thermal aging on the sealing effect must be considered. How to measure the sealing performance of the metal sealing ring after long-term use has become an urgent problem to be solved. Summary of the invention

[0003] The invention discloses a test method for simulating thermal aging of a metal sealing ring, aiming to solve the technical problems existing in the prior art.

[0004] The present invention adopts the following technical solutions:

[0005] The present invention provides a test method for simulating thermal aging of a metal sealing ring. The test method is performed by a test device, which includes a test container, a double sealing ring, a helium leak detector and a heating device. The test method includes the following steps:

[0006] Measuring initial dimensional parameters of the double sealing ring, wherein the dimensional parameters include inner diameter, outer diameter and wire diameter;

[0007] Installing the double sealing ring onto the test container and connecting the helium leak detector into the gap between the sealing rings of the double sealing ring;

[0008] Filling the test container with helium, and then placing it in the heating device for heating;

[0009] When the temperature of the double sealing ring rises to the test temperature T degrees Celsius, the temperature is maintained, and the leakage rate is recorded by the helium leak detector, and the recording time is t; the test temperature T and the recording time t are obtained by the Larson Muller formula LMP=T(C+log t), where C is a constant, T is the test temperature, K, t is the recording time, and H, LMP are acceleration characteristic parameters;

[0010] When the recording time reaches t, the experiment ends.

[0011] In the test method for simulating thermal aging of a metal sealing ring of the present invention, the test method further comprises:

[0012] After the space between the test container and the double sealing ring is evacuated, helium is filled into the test container.

[0013] In the test method for simulating thermal aging of a metal sealing ring of the present invention, the test method further comprises:

[0014] The heating device is stopped, the double sealing ring is taken out, and then cooled to room temperature, and the final dimensional parameters of the double sealing ring are measured.

[0015] The test method for simulating thermal aging of metal sealing rings of the present invention also includes summarizing test data, wherein the test data includes the name and size parameters of the double sealing rings, test temperature, leakage rate, test time, ambient temperature and ambient pressure.

[0016] In the test method for simulating thermal aging of a metal sealing ring of the present invention, the test container comprises a container body and a cover body; the container body and the cover body are screwed together; the double sealing ring is sandwiched between the container body and the cover body, and seals the container body and the cover body; the cover body is provided with a connecting hole connecting the gap between the double sealing rings; the connecting hole is used to connect with the helium leak detector.

[0017] In the test method for simulating thermal aging of a metal sealing ring of the present invention, the test device further comprises a helium concentration measuring element; the helium concentration measuring element is used to measure the helium concentration in the test container.

[0018] In the test method for simulating thermal aging of a metal sealing ring of the present invention, the test apparatus also includes the pressure regulating device; the pressure regulating assembly includes a valve, an air inlet pipe, a buffer tank and a pressure measuring element; the pressure measuring element is arranged in the test container and is used to measure the pressure in the test container; the air inlet pipe connects the buffer tank and the test container; the valve is arranged in the air inlet pipe and is opened or closed according to the measurement value of the pressure measuring element; the buffer tank is filled with helium, and the pressure is not higher than that of the test container.

[0019] In the test method for simulating thermal aging of a metal sealing ring of the present invention, the pressure regulating device also includes an outlet pipe and a gas delivery device; one end of the outlet pipe is connected to the buffer tank, and the other end is connected to the air inlet of the gas delivery device; the air outlet of the gas delivery device is connected to the test container.

[0020] In the test method for simulating thermal aging of a metal sealing ring of the present invention, the top surface and / or bottom surface of the outer sealing ring of the double sealing ring has a plurality of annular sealing structures; the plurality of annular sealing structures have different diameters and are concentrically arranged; each of the annular sealing structures includes an annular convex portion and an annular expansion body integrally formed with the outer sealing ring; an accommodating space is provided between the annular convex portion and the outer sealing ring; the annular expansion body is at least partially located in the accommodating space, and the annular expansion body can abut against the annular convex portion when the temperature rises, thereby changing the vertical distance between the annular convex portion and the surface of the outer sealing ring.

[0021] In the test method for simulating thermal aging of a metal sealing ring of the present invention, the thermal expansion coefficient of the outer sealing ring of the double sealing ring is greater than the thermal expansion coefficient of the inner sealing ring.

[0022] The technical solution adopted by the present invention can achieve the following beneficial effects:

[0023] The present invention mainly provides a test method for simulating thermal aging of a metal sealing ring. The test method is based on using a test device to test the sealing performance of the metal sealing ring after long-term use, and using a heating device to heat a test container, thereby simulating a high-temperature use environment. The test temperature and recording time calculated by the Larson Muller formula can simulate the performance change of the sealing ring after long-term use, and then the sealing performance is measured by a helium leak detector to obtain the sealing performance after long-term use. The test process is simple and time-consuming, and can help container designers to grasp the law of performance decay and service life of the metal sealing ring. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments, which constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions explain the present invention and do not constitute improper limitations on the present invention. In the drawings:

[0025] Figure 1 A flow chart of a test method for simulating thermal aging of a metal sealing ring according to the present invention;

[0026] Figure 2 This is one of the structural schematic diagrams of a test device in a test method for simulating thermal aging of a metal sealing ring of the present invention;

[0027] Figure 3 This is a second structural schematic diagram of a test device in a test method for simulating thermal aging of a metal sealing ring according to the present invention;

[0028] Figure 4The cross-sectional structure diagram of the double sealing rings of the test device in the test method for simulating thermal aging of metal sealing rings of the present invention.

[0029] Description of reference numerals:

[0030] 1. Test container; 11. Container body; 12. Cover body; 121. Communication hole; 2. Double sealing ring; 21. Outer sealing ring; 22. Inner sealing ring; 23. Annular sealing structure; 231. Annular convex part; 232. Annular expansion body; 233. Accommodation space; 3. Helium leak detector; 4. Heating device; 5. Helium concentration measuring element; 6. Pressure regulating equipment; 61. Valve; 62. Inlet pipe; 63. Buffer tank; 64. Pressure measuring element; 65. Outlet pipe; 66. Gas delivery equipment. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. In the description of the present invention, it should be noted that the term "or" is usually used in the sense of including "and / or", unless the content clearly indicates otherwise.

[0032] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or a magnetic connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In addition, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance. In the description of the present invention, the meaning of "multiple" is at least two, such as two, three or more, etc., unless otherwise clearly and specifically limited.

[0033] Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] In order to solve the problems existing in the prior art, an embodiment of the present application provides a test method for simulating thermal aging of a metal sealing ring.

[0035] like Figure 1 and 2As shown, a test method for simulating thermal aging of a metal sealing ring is performed by a test device, the test device comprising a test container 1, a double sealing ring 2, a helium leak detector 3 and a heating device 4, such as a high temperature test box; the test method comprises the following steps:

[0036] The initial dimensional parameters of the double sealing ring 2 are measured, and the dimensional parameters include the inner diameter, the outer diameter and the wire diameter.

[0037] Install the double sealing ring 2 onto the test container 1, and connect the helium leak detector 3 into the gap between the sealing rings of the double sealing ring 2;

[0038] Fill the test container 1 with helium and then place it in the heating device 4 for heating;

[0039] When the temperature of the double sealing ring 2 rises to the test temperature T degrees Celsius, the temperature is maintained, and the leakage rate is recorded by the helium leak detector 3, and the recording time is t; the test temperature T and the recording time t are obtained by the Larson Muller formula LMP=T(C+logt), wherein C is a constant, T is the test temperature, K, t is the recording time, and H, LMP are acceleration characteristic parameters; wherein the values ​​of LMP and C can refer to existing empirical data, or can be determined by experimental data regression. For example, when LMP=7232 and C=14, the calculated recording time t and test temperature T can reflect the aging degree of the double sealing ring 2 with a service time of 60 years;

[0040] When the recording time reaches t, the experiment ends.

[0041] A test method for simulating thermal aging of a metal sealing ring of the present invention is based on using a test device to test the sealing performance of the metal sealing ring after long-term use, and using a heating device to heat the test container to simulate a high-temperature use environment. The test temperature and recording time calculated by the Larson Muller formula can simulate the performance change of the sealing ring after long-term use, and then the sealing performance is measured by a helium leak detector to obtain the sealing performance after long-term use. The test process is simple and time-consuming, and can help container designers to grasp the law of performance decay and service life of the metal sealing ring.

[0042] In some preferred embodiments, the values ​​of LMP and C can be determined by regression of experimental data by setting different test temperatures T and recording time t through overheat aging test methods, and measuring the residual stress of the metal sealing ring after each test. Selecting data with the same residual stress, a curve logt = LMP*1 / TC can be obtained. When the curve intersects with the Y axis, that is, 1 / T = 0, logt = -C can be obtained, and then the C value can be obtained. The value of LMP can be obtained by calculating the C value, setting different test temperatures T and recording time t, and obtaining the corresponding curve. The slope of the curve is the value of LMP; or, the values ​​of LMP and C can be obtained by other existing methods.

[0043] In some preferred embodiments, the test method further comprises:

[0044] After evacuating the space between the test container 1 and the double sealing ring 2, helium is filled into the test container 1; by filling the test container 1 with helium after evacuating the space, the influence of impurity gases on the experimental results can be reduced.

[0045] In some preferred embodiments, the test method further comprises:

[0046] Stop the heating device 4, take out the double sealing ring 2, cool it to room temperature, and measure the final dimensional parameters of the double sealing ring 2; by comparing the final dimensional parameters with the initial dimensional parameters, the different parameters of the double sealing ring 2 after aging can be more comprehensively recorded, thereby guiding the container design work.

[0047] In some preferred embodiments, test data are also summarized, including the name and size parameters (inner diameter, outer diameter, wire diameter) of the double sealing ring 2, test temperature, leakage rate, test time, ambient temperature and ambient pressure.

[0048] In some preferred embodiments, the test container 1 includes a container body 11 and a cover body 12; the container body 11 and the cover body 12 are screwed; the double sealing ring 2 is sandwiched between the container body 11 and the cover body 12, and the container body 11 and the cover body 12 are sealed and connected to form a sealed space; the cover body 12 is provided with a connecting hole 121 connecting the gap between the double sealing rings 2; the connecting hole 121 is used to communicate with the helium leak detector 3; specifically, the degree of tightening between the container body 11 and the cover body 12 by bolts is according to the degree of tightening of the container during actual use.

[0049] In some preferred embodiments, the test device further includes a helium concentration measuring element 5; the helium concentration measuring element 5 is used to measure the helium concentration in the test container 1; based on the setting of the helium concentration measuring element 5, the helium concentration in the test container 1 can be measured, and then the calculated value of the helium leak detector 3 can be corrected, so that the leakage rate measurement is more accurate; specifically, the calculated value of the helium leak detector 3 is corrected by the following formula;

[0050]

[0051] In the formula,

[0052] Q air It is the leakage rate value under standard air conditions (standard atmospheric pressure, 25°C);

[0053] Q mix It is the value actually measured by helium mass spectrometer leak detector;

[0054] P mix is the pressure of the mixed gas (helium and air mixed gas) inside the first space 141;

[0055] P He is the helium partial pressure inside the first space 141;

[0056] μ air , μ He are the dynamic viscosities of air and helium, respectively;

[0057] Pu is the environmental pressure in the test;

[0058] Pd is the pressure between the two seal rings in the test;

[0059] P std is standard atmospheric pressure.

[0060] In some preferred embodiments, Figure 3As shown, the test device also includes a pressure regulating device 6; the pressure regulating assembly 6 includes a valve 61, an air inlet pipe 62, a buffer tank 63 and a pressure measuring element 64; the pressure measuring element 64 is arranged in the test container 1, and is used to measure the pressure in the test container 1; the air inlet pipe 62 connects the buffer tank 63 and the test container 1; the valve 61 is arranged in the air inlet pipe 62, and the valve 61 is opened or closed according to the measurement value of the pressure measuring element 65; the buffer tank 63 is filled with helium, and the pressure is not higher than that of the test container 1; based on the setting of the pressure regulating device 6, the pressure value in the test container 1 can be adjusted, and then it can be controlled under the use pressure, reducing the influence of the pressure increase in the test container 1 caused by the temperature rise on the leakage rate measurement; specifically, the pressure measuring element 64 can be selected as a pressure gauge or a pressure sensor, and the valve 61 can be a manual valve or an automatic valve. Preferably, the valve 61 is an automatic valve, and the pressure measuring element 64 is a pressure sensor, and both are connected to the PLC, and the automatic control of the pressure in the test container 1 is realized through program control, so that the control is more timely.

[0061] In some preferred embodiments, the pressure regulating device 6 also includes an outlet pipe 65 and a gas delivery device 66; one end of the outlet pipe 65 is connected to the buffer tank 63, and the other end is connected to the air inlet of the gas delivery device 66; the outlet of the gas delivery device 66 is connected to the test container 1; the gas in the buffer tank 63 is transported out by the gas delivery device 66, which can reduce the pressure in the buffer tank 63 and avoid the speed of the gas in the test container 1 entering the buffer tank 63 due to excessive pressure, and the outlet of the gas delivery device 66 is connected to the test container 1. On the one hand, it avoids the waste of helium, and on the other hand, it makes the gas in the test container 1 more uniform, thereby improving the accuracy of the leakage rate measurement; and the buffer tank 63 can be filled with gas, and then transported to the test container 1 through the gas delivery device 66 to avoid opening in the test container 1.

[0062] In some preferred embodiments, Figure 4As shown, the top surface and / or bottom surface of the outer sealing ring 21 of the double sealing ring 2 has multiple annular sealing structures 23; the multiple annular sealing structures 23 have different diameters and are concentrically arranged; each annular sealing structure 23 includes an annular convex portion 231 and an annular expansion body 232 integrally formed with the outer sealing ring 21; there is a accommodating space 233 between the annular convex portion 231 and the outer sealing ring 21; the annular expansion body 232 is at least partially located in the accommodating space 233, and the annular expansion body 232 can abut against the annular convex portion 231 when the temperature rises, thereby changing the vertical distance between the annular convex portion 231 and the surface of the outer sealing ring 21; based on the arrangement of the multiple annular sealing structures 23, the surface of the outer sealing ring 21 in contact with the container body 11 and / or the cover body 12 of the test container 1 has multiple seals, thereby preventing the gas in the environment from entering the gap between the double sealing rings 2 and affecting the leakage rate measurement. The accuracy of the measurement; and based on the annular sealing structure 23 being set to include an annular convex portion 231 and an annular expansion body 232, wherein the annular convex portion 231 is used to abut and seal with the container body 11 and / or the cover body 12, and is arranged in a receiving space 233 formed by the abutting portion of the annular convex portion 231 and the surface of the outer sealing ring 21. For example, at room temperature, the annular expansion body 232 and the receiving space 233 are gap-matched. When the temperature rises, the annular expansion body 232 expands and abuts against the annular convex portion 231, thereby pushing the annular convex portion 231 away from the surface of the outer sealing ring 21, thereby improving the sealing with the container body 11 and the cover body 12, thereby further reducing the possibility of gas in the environment entering the gap between the double sealing rings 2; specifically, the annular expansion body 232 can be a metal material with a thermal expansion coefficient higher than that of the outer sealing ring 21, and can be an integral structure or a split structure.

[0063] In some preferred embodiments, the thermal expansion coefficient of the outer sealing ring 21 of the double sealing ring 2 is greater than the thermal expansion coefficient of the inner sealing ring 22; based on this, when the temperature rises, the outer sealing ring 21 abuts more tightly against the container body 11 and the cover body 12, thereby improving the sealing performance, reducing the entry of gas in the environment into the gap between the double sealing rings 2, and improving the accuracy of the leakage rate measurement of the double sealing ring 2.

[0064] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. A test method for simulating thermal aging of a metal sealing ring, the test method being carried out by a test device, the test device comprising a test container, a double sealing ring, a helium leak detector and a heating device; characterized in that: The test method comprises the following steps: Measuring initial dimensional parameters of the double sealing ring, wherein the dimensional parameters include inner diameter, outer diameter and wire diameter; Installing the double sealing ring onto the test container and connecting the helium leak detector into the gap between the sealing rings of the double sealing ring; Filling the test container with helium, and then placing it in the heating device for heating; When the temperature of the double sealing ring rises to the test temperature T degrees Celsius, the temperature is maintained, and the leakage rate is recorded by the helium leak detector, and the recording time is t; the test temperature T and the recording time t are obtained by the Larson Muller formula LMP=T(C+log t), where C is a constant, T is the test temperature, K, t is the recording time, and H, LMP are acceleration characteristic parameters; When the recording time reaches t, the experiment ends.

2. The test method for simulating thermal aging of a metal sealing ring according to claim 1, characterized in that: The test method also includes: After the space between the test container and the double sealing ring is evacuated, helium is filled into the test container.

3. The test method for simulating thermal aging of a metal sealing ring according to claim 1, characterized in that: The test method also includes: The heating device is stopped, the double sealing ring is taken out, and then cooled to room temperature, and the final dimensional parameters of the double sealing ring are measured.

4. The test method for simulating thermal aging of a metal sealing ring according to claim 1, characterized in that: The test container comprises a container body and a cover body; The container body and the cover body are screwed together; The double sealing ring is sandwiched between the container body and the cover body, and seals the container body and the cover body; The cover body is provided with a connecting hole connecting the gap between the double sealing rings; The communicating hole is used to communicate with the helium leak detector.

5. The test method for simulating thermal aging of a metal sealing ring according to claim 1, characterized in that: The test device also includes a helium concentration measuring element; The helium concentration measuring element is used to measure the helium concentration in the test container.

6. The test method for simulating thermal aging of a metal sealing ring according to claim 4, characterized in that: The test apparatus further comprises the pressure regulating device; The pressure regulating assembly includes a valve, an air inlet pipe, a buffer tank and a pressure measuring element; The pressure measuring element is disposed in the test container and is used to measure the pressure in the test container; The air inlet pipe is connected to the buffer tank and the test container; The valve is arranged on the air inlet pipe, and is opened or closed according to the measured value of the pressure measuring element; The buffer tank is filled with helium, and the pressure is no higher than that of the test container.

7. The test method for simulating thermal aging of a metal sealing ring according to claim 6, characterized in that: The pressure regulating device also includes a gas outlet pipe and a gas delivery device; One end of the gas outlet pipe is connected to the buffer tank, and the other end is connected to the gas inlet of the gas delivery device; The gas outlet of the gas delivery device is connected to the test container.

8. The test method for simulating thermal aging of a metal sealing ring according to claim 1, characterized in that: The top surface and / or bottom surface of the outer sealing ring of the double sealing ring has a plurality of annular sealing structures; the plurality of annular sealing structures have different diameters and are concentrically arranged; Each of the annular sealing structures comprises an annular convex portion and an annular expansion body integrally formed with the outer sealing ring; There is an accommodating space between the annular protrusion and the outer sealing ring; The annular expansion body is at least partially located in the accommodating space, and the annular expansion body can press against the annular convex portion when the temperature rises, thereby changing the vertical distance between the annular convex portion and the outer sealing ring surface.

9. The test method for simulating thermal aging of a metal sealing ring according to claim 1, characterized in that: The thermal expansion coefficient of the outer sealing ring of the double sealing ring is greater than the thermal expansion coefficient of the inner sealing ring.

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