Hydrogen permeation device and hydrogen permeation method
By creating a temperature gradient in the heating element of the hydrogen permeation device, the diffusion of hydrogen in the cladding tube is prevented, thus solving the problem of inaccurate hydrogen distribution simulation in the prior art, achieving a more realistic hydrogen distribution simulation, and improving the accuracy of the research.
Patent Information
- Application Number
- CN202511079714.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-01
- Publication Date
- 2025-11-07
AI Technical Summary
Existing technologies cannot realistically simulate the non-uniform hydrogen distribution in the fuel element cladding tubes within the reactor, thus affecting the study of mechanical performance and structural integrity.
Design a hydrogen permeation device that uses a heating element to heat the outer surface of the cladding tube to a temperature higher than that of the simulated coolant liquid, creating a temperature gradient. This temperature gradient is used to prevent hydrogen from diffusing from the outside to the inside, simulating the enrichment of hydrogen inside the cladding tube.
This method enables a more realistic simulation of hydrogen permeation through the cladding tubes within the reactor, improves the non-uniformity of hydrogen distribution, and enhances the accuracy of studies on mechanical properties and structural integrity.
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Figure CN120908046A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] Embodiments of the present application relate to the technical field of devices for detecting fuel elements, and in particular to a hydrogen permeation device and a hydrogen permeation method. BACKGROUND
[0002] The statements herein are merely provided to give a basic understanding of the present application and are not necessarily intended to constitute the prior art.
[0003] In a nuclear reactor, the cladding tube of a fuel element is directly contacted with an external coolant, and the surface of the cladding tube is uniformly corroded by the coolant and generates hydrogen gas. The generated hydrogen gas diffuses in the wall of the cladding tube in a non-uniform distribution state with a certain tendency, which has an impact on the mechanical properties, fatigue life and structural integrity of the cladding tube. Therefore, it is necessary to simulate the non-uniform distribution state of the hydrogen gas for research.
[0004] However, in the prior art, there are still many problems in simulating the non-uniform distribution state of the hydrogen gas, which is difficult to be used in the mechanical property research of the cladding tube. SUMMARY
[0005] In the following, a brief overview of the present application is given to provide a basic understanding of some aspects of the present application. It should be understood that this overview is not an exhaustive overview of the present application. It is not intended to identify key or important parts of the present application nor is it intended to limit the scope of the present application. Its purpose is merely to present some concepts in a simplified form as a prelude to the more detailed description that is discussed later.
[0006] In a first aspect, embodiments of the present application provide a hydrogen permeation device for simulating the hydrogen permeation condition of a cladding tube in a reactor, comprising a shell and a heating element. The shell is configured to form a containing cavity for containing a coolant simulation liquid and heating the coolant simulation liquid, wherein the cladding tube is arranged in the containing cavity, and the coolant simulation liquid in the containing cavity can react with the cladding tube to form hydrogen gas. The heating element is used to provide heat to simulate the fuel in the cladding tube, and the cladding tube is sealingly arranged on the radial outside of the heating element to prevent the coolant simulation liquid from entering the inside of the cladding tube during the hydrogen permeation process. The heating element is configured to heat the temperature of the outer surface of the cladding tube to be higher than the temperature of the coolant simulation liquid by a preset value, and maintain the preset time while the cladding tube remains sealed.
[0007] The hydrogen permeation device provided by the embodiments of the present application is configured to provide heat to simulate fuel in the cladding tube by means of the heating element, and the cladding tube is sealingly arranged on the radially outer side of the heating element, so that the heating element is used to heat the side of the cladding tube wall close to the radially inner side, thereby heating the outer side surface of the cladding tube to a temperature higher than that of the coolant simulation liquid by a preset value, so as to ensure that a temperature gradient is formed between the inner and outer side surfaces of the cladding tube wall, and the hydrogen permeation condition of the cladding tube in the reactor is more realistically simulated.
[0008] In a second aspect, the embodiments of the present application provide a hydrogen permeation method for simulating the hydrogen permeation condition of a cladding tube in a reactor, which is implemented by using the hydrogen permeation device of the first aspect of the present application, and includes the following steps: S1, assembling the cladding tube and the heating element to sealingly arrange the cladding tube on the radially outer side of the heating element; S2, placing the cladding tube and the heating element in the containing cavity; S3, adding the coolant simulation liquid into the containing cavity, and heating the coolant simulation liquid to a preset temperature; and S4, starting the heating element to heat the outer side surface of the cladding tube to a temperature higher than that of the coolant simulation liquid, so as to form a temperature difference between the inner and outer sides of the cladding tube wall, and maintain the preset time under the condition that the cladding tube remains sealed.
[0009] The hydrogen permeation method provided by the embodiments of the present application is configured to heat the coolant simulation liquid to a preset temperature by using the hydrogen permeation device of the first aspect of the present application, heat the outer side surface of the cladding tube to a temperature higher than that of the coolant simulation liquid, form a temperature difference between the inner and outer sides of the cladding tube wall, form a temperature gradient in the tube wall, thereby prevent hydrogen from diffusing from the side of the cladding tube wall close to the radially outer side to the side close to the radially inner side by using the temperature gradient of the tube wall, enrich hydrogen on the side of the cladding tube wall close to the radially outer side, and more realistically simulate the hydrogen permeation condition of the cladding tube in the reactor. BRIEF DESCRIPTION OF DRAWINGS
[0010] Other purposes and advantages of the present application will be apparent from the following description of the embodiments of the present application with reference to the accompanying drawings, and can help to have a comprehensive understanding of the present application.
[0011] Figure 1 is a perspective view of a hydrogen permeation device according to an embodiment of the present application;
[0012] Figure 2 is a schematic diagram of the distribution of hydrogen atoms in a cladding tube, in which the hydrogen atoms are driven to diffuse in the tube wall of the cladding tube by the concentration difference;
[0013] Figure 3 is a schematic diagram of the distribution of hydrogen atoms in a cladding tube, in which the hydrogen atoms are driven to diffuse in the tube wall of the cladding tube by the concentration difference and the temperature difference;
[0014] Figure 4is a perspective view of a hydrogen permeation apparatus provided with a plurality of partition members according to an embodiment of the present application, the hydrogen permeation apparatus being in a state where a cladding tube is not installed;
[0015] Figure 5 is a perspective view of a hydrogen permeation apparatus provided with a plurality of partition members according to an embodiment of the present application, the hydrogen permeation apparatus being in a state where a cladding tube is installed;
[0016] Figure 6 is a metallographic micrograph of the hydrogen distribution inside the tube wall of a cladding tube after simulating the hydrogen permeation of the cladding tube in a reactor using a hydrogen permeation apparatus according to an embodiment of the present application;
[0017] Figure 7 is Figure 6 an enlarged view of the metallographic micrograph shown in Fig. 6.
[0018] BRIEF DESCRIPTION OF DRAWINGS
[0019] 10, shell member; 11, accommodation cavity; 111, sub-chamber; 12, cover; 13, base; 20, heating member; 30, cladding tube; 31, radially outer surface; 32, radially inner surface; 41, first temperature measuring member; 42, second temperature measuring member; 43, fixing member; 50, partition member; 51, clearance hole; 60, sealing member; 70, hydrogen atom; 80, long strip-shaped hydride structure.
[0020] It should be noted that the accompanying drawings are not necessarily drawn to scale, but are merely intended to show illustrative aspects of the application in a schematic manner. DETAILED DESCRIPTION
[0021] In the following, exemplary embodiments of the present application will be described with reference to the accompanying drawings. In the description, not all of the features of the actual implementation are described in order to conciseness and brevity. It should be appreciated, however, that in the development of any such actual implementation numerous implementation-specific decisions must be made in order to achieve the developer's specific goals, such as compliance with system- and business-related constraints, which will vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.
[0022] It should also be noted that, in the description, only the device structures and / or processing steps closely related to the solution according to the present application are shown in the drawings, and other details not closely related to the present application are omitted.
[0023] In related technologies, when simulating hydrogen permeation of the cladding tube in a reactor, the cladding tube is usually placed in a simulated coolant liquid. After the simulated coolant liquid is heated to the actual operating temperature in the reactor, it reacts with the cladding tube to form hydrogen gas. The hydrogen concentration difference is used to drive the hydrogen gas to diffuse in the tube wall.
[0024] The inventors of this application discovered that during the diffusion of hydrogen atoms driven by concentration difference in the tube wall of the cladding tube, the concentration of hydrogen atoms on the side of the tube wall closer to the radial outer surface is slightly higher than that on the side closer to the radial inner surface. Compared with the actual situation of hydrogen permeation in the cladding tube in the reactor, the concentration difference of hydrogen distribution in the simulated cladding tube is not obvious enough and it is difficult to reflect the real hydrogen permeation situation in the cladding tube in the reactor.
[0025] The inventors of this application further discovered that the above situation is caused by the high temperature of the fuel pellets inside the cladding tube during reactor operation, which makes the temperature of the inner surface of the cladding tube wall higher than that of its outer surface, thereby forming a temperature gradient in the cladding tube wall. This temperature gradient prevents hydrogen from diffusing from the side of the cladding tube wall near the outer surface to the side near the inner surface, causing hydrogen to accumulate on the side of the cladding tube wall near the outer surface. As a result, the concentration of hydrogen atoms on the side of the tube wall near the radially outer surface is significantly higher than the concentration on the side near the radially inner surface.
[0026] Based on this, embodiments of this application provide a hydrogen permeation device for more realistically simulating hydrogen permeation of cladding tubes within a reactor.
[0027] like Figure 1 As shown, Figure 1 This diagram illustrates the structure of a hydrogen permeation apparatus according to an embodiment of this application. The hydrogen permeation apparatus provided in this embodiment includes a housing 10 and a heating element 20. The housing 10 is configured to form a receiving cavity 11 for containing and heating a simulated coolant liquid. A casing tube 30 is disposed in the receiving cavity 11, and the simulated coolant liquid in the receiving cavity 11 can react with the casing tube 30 to form hydrogen gas. The heating element 20 provides heat to simulate fuel within the casing tube 30. The casing tube 30 is sealed radially outside the heating element 20 to prevent the simulated coolant liquid from entering the interior of the casing tube 30 during the hydrogen permeation process. The heating element 20 is configured to heat the outer surface of the casing tube 30 to a temperature higher than the temperature of the simulated coolant liquid, and maintain this temperature for a preset time while the casing tube 30 remains sealed. This allows hydrogen gas to permeate along the outer surface of the casing tube 30 into the interior of the casing tube 30 wall when a temperature difference is formed between the inner and outer surfaces of the casing tube 30 wall.
[0028] The hydrogen permeation device provided by the embodiments of the present application can more realistically simulate the hydrogen permeation condition of the cladding tube 30 in the reactor. Specifically, as shown in
[0029] Specifically, as shown in Figure 2 and Figure 3 , Figure 2 is a distribution diagram of hydrogen atoms in the cladding tube, wherein the hydrogen atoms are driven to diffuse in the tube wall of the cladding tube by the concentration difference; Figure 3 is a distribution diagram of hydrogen atoms in the cladding tube, wherein the hydrogen atoms are driven to diffuse in the tube wall of the cladding tube by the concentration difference and the temperature difference. See Figure 2 When the inner wall of the cladding tube 30 does not form a temperature difference, the concentration of the hydrogen atoms 70 on the side of the tube wall of the cladding tube 30 close to the radially outer side surface 31 is relatively high, and the concentration on the side close to the radially inner side surface 32 is relatively low, and the concentration difference between the two sides is not obvious enough; see Figure 3 When the hydrogen permeation device provided by the embodiments of the present application is used to permeate hydrogen into the cladding tube, the heating element 20 heats the side of the tube wall of the cladding tube 30 close to the radially inner side surface, so as to form a temperature gradient, prevent the hydrogen atoms 70 from diffusing from the side of the tube wall of the cladding tube 30 close to the radially outer side surface 31 to the side close to the radially inner side surface 32, and thus enrich the hydrogen gas on the side of the tube wall of the cladding tube 30 close to the radially outer side surface 31, and the concentration difference between the two sides of the tube wall of the cladding tube 30 is obvious.
[0030] In some embodiments, the shell 10 is made of a material with corrosion resistance and suitable for high temperature and high pressure environment in the reactor. For example, the shell 10 is made of nickel-based alloy or stainless steel.
[0031] In some embodiments, the heating element 20 is an electric resistance heating rod or an inductive heating device.
[0032] In some embodiments, the cladding tube 30 is arranged to seal the heating element 20 inside, and the power supply line of the heating element 20 extends outside the cladding tube 30. In some embodiments, the heating element 20 protrudes axially from the top end of the cladding tube 30, as shown in the figure, and the liquid level of the coolant simulation liquid in the accommodating cavity 11 is arranged to be lower than the top end of the cladding tube 30 and not in contact with the heating element 20; or, the part of the heating element 20 protruding from the top end of the cladding tube 30 is a non-heating section, so as to avoid the heating part of the heating element 20 from being in contact with the coolant simulation liquid and affecting the heating effect of the heating element 20 on the cladding tube 30. Figure 1
[0033] Since the heating element 20 will be deformed due to thermal expansion after being heated, if the distance between the cladding tube 30 and the heating element 20 is too close, the cladding tube 30 is easy to be deformed by heat and tightly adhere to the heating element 20, thereby causing local overheating and even causing the heating element 20 and the cladding tube 30 to be inseparable, which affects the test on the cladding tube 30; and since the tube wall on the radial outside of the cladding tube 30 needs to bear a large external pressure (about 18.5 MPa), if the distance between the cladding tube 30 and the heating element 20 is too large, the cladding tube 30 is easy to be severely deformed.
[0034] In view of the above problems, in some embodiments of the present application, the hydrogen permeation device can further comprise: an elastic buffer arranged between the cladding tube 30 and the heating element 20, for providing elastic deformation when the heating element 20 is thermally expanded, so as to avoid the heating element 20 from pressing the cladding tube 30, so that the cladding tube 30 can maintain a proper distance from the heating element 20, avoid the cladding tube 30 from being deformed by heat and tightly adhering to the heating element 20, and also avoid the cladding tube 30 from being severely deformed due to being unable to bear the external pressure.
[0035] In some embodiments, the elastic buffer is a metal bellows or a spring, which is sleeved outside the heating element 20 and located inside the cladding tube 30, so as to utilize the physical properties of the metal bellows or the spring to provide elastic deformation when the heating element 20 is thermally expanded, so that the cladding tube 30 can maintain a certain gap from the heating element 20, and avoid the heating element 20 from directly pressing the cladding tube 30.
[0036] In some embodiments, the hydrogen permeation device can further comprise: a first temperature measuring element 41, a second temperature measuring element 42, and a control element. The first temperature measuring element 41 is used to measure the temperature of the outer surface of the cladding tube 30. The second temperature measuring element 42 is used to measure the temperature of the coolant simulation liquid. The control element is arranged to adjust the heating power of the heating element 20 according to the temperature difference measured by the first temperature measuring element 41 and the second temperature measuring element 42 when the temperature measured by the second temperature measuring element 42 is a preset temperature, so as to make the temperature difference a preset value.
[0037] In the embodiment, the second temperature measuring member 42 is arranged to measure the temperature of the coolant simulation liquid, so that the temperature of the coolant simulation liquid can be the same as the temperature of the coolant in the reactor; the first temperature measuring member 41 is arranged to measure the temperature of the outer surface of the cladding tube 30, so that the temperature difference between the outer surface of the cladding tube 30 and the coolant simulation liquid can be obtained, and the control member adjusts the heating power of the heating member 20 according to the temperature difference when the temperature measured by the second temperature measuring member 42 is the preset temperature, so that the temperature difference is the preset value, thereby more truly simulating the actual situation in the reactor, and ensuring that the temperature of the outer surface of the cladding tube 30 is always greater than the temperature of the coolant simulation liquid, which is conducive to forming a temperature gradient in the wall of the cladding tube 30.
[0038] In some embodiments, the preset temperature can be 290-320℃, and the preset value can be 20℃, that is, when the temperature of the coolant simulation liquid measured by the second temperature measuring member 42 reaches 290-320℃, the control member adjusts the heating power of the heating member 20 according to the temperature difference between the temperature measured by the second temperature measuring member 42 and the temperature of the outer surface of the cladding tube 30 measured by the first temperature measuring member 41, so that the temperature difference can be maintained at 20℃.
[0039] In some embodiments, the hydrogen permeation device can further include a pressure measuring member for measuring the pressure in the containing cavity 11. The control member adjusts the heating power of the shell member 10 according to the pressure measured by the pressure measuring member, so as to increase the pressure in the containing cavity 11 to a preset pressure.
[0040] In the embodiment, the pressure measuring member is arranged to measure the pressure in the containing cavity 11, so as to monitor the pressure in the containing cavity 11 in real time, and the control member adjusts the heating power of the shell member 10 according to the pressure measured by the pressure measuring member, so as to increase the pressure in the containing cavity 11 to a preset pressure by heating the coolant simulation liquid in the containing cavity 11, thereby facilitating the simulation of the high-pressure environment generated by the reactor in actual operation, and facilitating the simulation of the hydrogen permeation of the cladding tube 30 in the reactor by the hydrogen permeation device.
[0041] In some embodiments, the shell member 10 includes a base 13 and a cover 12 covering the base 13, and the base 13 and the cover 12 jointly form the containing cavity 11. One end of the cladding tube 30 can be fixed to the base 13 to avoid contact between the cladding tube 30 and the cover 12. The cladding tube 30 can be fixed to the base 13 by the fixing member 43.
[0042] The shell member 10 can further include a shell heating member for heating the coolant simulation liquid in the containing cavity 11.
[0043] Please refer to Figure 4 and Figure 5 , Figure 4Fig. 2 shows a perspective view of the hydrogen permeation device with multiple partitions according to an embodiment of the present application, in which the cladding tube 30 is not installed; Figure 5 Fig. 3 shows a perspective view of the hydrogen permeation device with multiple partitions according to an embodiment of the present application, in which the cladding tube 30 is installed.
[0044] In some embodiments, the hydrogen permeation device can further comprise at least one partition 50, which divides the accommodation cavity 11 into multiple sub-chambers 111 that are not in communication with each other. Each partition 50 forms a clearance hole 51 for the cladding tube 30 to pass through. The cladding tube 30 passes through each clearance hole 51 and enters each sub-chamber 111.
[0045] In the present embodiment, the accommodation cavity 11 is divided into multiple sub-chambers 111 that are not in communication with each other by means of the at least one partition 50, so as to independently control the reaction environment of each sub-chamber 111, to enable each sub-chamber 111 to form a different reaction environment. The cladding tube 30 is passed through the clearance hole 51 formed by each partition 50, so that different regions of the cladding tube 30 are respectively in different reaction environments, thereby forming a hydrogen concentration gradient in the axial direction of the cladding tube 30, which facilitates the simulation of hydrogen permeation of the same cladding tube 30 under different operating conditions of the reactor at the same time.
[0046] In some embodiments, multiple second temperature measuring members 42 and pressure measuring members can be provided, and are respectively arranged in each sub-chamber 111, for measuring the temperature of the coolant simulation liquid in each sub-chamber 111 and the pressure of each sub-chamber 111, so as to adjust the temperature and pressure of each sub-chamber 111 in real time according to the measurement data.
[0047] In some embodiments, the coolant simulation liquid in each sub-chamber 111 can be different, so as to enable each sub-chamber 111 to form a different reaction environment, thereby enabling different regions of the cladding tube 30 to be respectively in different reaction environments.
[0048] In some embodiments, the hole wall of the clearance hole 51 is provided with a sealing member that matches the tube wall of the cladding tube 30, so that after the cladding tube 30 passes through each clearance hole 51, each sub-chamber 111 is not in communication with each other.
[0049] Since lithium hydroxide is contained in the water coolant during the actual operation of the reactor, in some embodiments of the present application, the coolant simulation liquid is a lithium hydroxide aqueous solution. The concentration of lithium hydroxide in the aqueous solution can be higher than the concentration of lithium hydroxide in the actual coolant in the reactor, so as to increase the reaction rate of the reaction between the coolant simulation liquid and the cladding tube 30, thereby enhancing the permeation rate of hydrogen gas permeating into the tube wall of the cladding tube 30.
[0050] In some embodiments, the concentration of lithium hydroxide in the simulated coolant liquid is 0.8-1.2 mol / L.
[0051] Compared to increasing the lithium hydroxide concentration, increasing the reaction temperature to increase the reaction rate would result in a more uniform diffusion of hydrogen in the wall of the cladding tube 30, which does not match the non-uniform distribution of hydrogen in the cladding tube 30 that is to be simulated.
[0052] In some embodiments, a lower concentration of LiOH solution can be used in one sub-chamber 111 to control the reaction rate, resulting in a slower hydrogen permeation rate in that region of the cladding tube 30. Conversely, a higher concentration of LiOH solution is used in the other sub-chamber 111. Combined with different temperature and pressure parameters, this promotes more rapid diffusion or enrichment of hydrogen in that region of the cladding tube 30. Thus, by controlling the experimental conditions in each sub-chamber 111, the desired hydrogen concentration gradient is formed in the longitudinal direction of the entire cladding tube 30, thereby satisfying the precise setting of hydrogen distribution under different operating conditions or experimental requirements.
[0053] In some embodiments, the coolant simulating liquid may also be other aqueous solutions that can react with the cladding tube 30 to generate hydrogen gas, such as aqueous solutions containing acidic solutions HCl, H2SO4, strong base NaOH, and halogen salts NaCl and HF.
[0054] like Figure 1 As shown, in some embodiments, the hydrogen permeation device may further include: a seal 60 for sealing the axial end of the casing tube 30 so as to seal the casing tube 30 on the radially outer side of the heating element 20, preventing the coolant simulated liquid in the receiving cavity 11 from entering the interior of the casing tube 30, thereby avoiding contact between the heating element 20 and the coolant simulated liquid.
[0055] In some embodiments, two seals 60 may be provided to seal the axial ends of the casing tube 30 respectively, so as to further enhance the sealing effect.
[0056] In some embodiments, the seal 60 is made of a sealing material suitable for the high temperature and high pressure environment inside the reactor. For example, the seal 60 can be a high temperature resistant rubber seal or a metal seal.
[0057] The embodiments of this application also provide a hydrogen permeation method for simulating hydrogen permeation of cladding tubes in a reactor. This hydrogen permeation method is implemented using the hydrogen permeation apparatus provided in the embodiments of this application, and includes steps S1 to S4.
[0058] S1. Assemble the casing tube 30 and the heating element 20 so that the casing tube 30 is sealed on the radial outer side of the heating element 20.
[0059] S2, place the cladding tube 30 and the heating element 20 into the containing cavity 11 together.
[0060] S3, add the coolant simulation liquid into the containing cavity 11, and heat the coolant simulation liquid to a preset temperature.
[0061] S4, start the heating element 20, heat the outer surface of the cladding tube 30 to a temperature higher than that of the coolant simulation liquid, form a temperature difference between the inner and outer sides of the tube wall of the cladding tube 30, and maintain the preset time while the cladding tube 30 remains sealed.
[0062] The hydrogen permeation method provided by the embodiments of the present application can more realistically simulate the hydrogen permeation condition of the cladding tube 30 in the reactor by using the hydrogen permeation device provided by the embodiments of the present application, heating the coolant simulation liquid to a preset temperature, heating the outer surface of the cladding tube 30 to a temperature higher than that of the coolant simulation liquid, forming a temperature difference between the inner and outer sides of the tube wall of the cladding tube 30, forming a temperature gradient in the tube wall, and preventing the hydrogen from diffusing from the side close to the radially outer surface to the side close to the radially inner surface of the tube wall of the cladding tube 30 by using the temperature gradient of the tube wall, so that the hydrogen is enriched on the side close to the radially outer surface of the tube wall of the cladding tube 30.
[0063] In some embodiments, the temperature difference in the S4 step can be 20℃. By heating the coolant simulation liquid and the cladding tube 30 respectively, a 20℃ temperature difference is formed between the inner and outer sides of the tube wall of the cladding tube 30, so as to form a stable temperature gradient, facilitate the prevention of the hydrogen from diffusing from the side close to the radially outer surface to the side close to the radially inner surface of the tube wall of the cladding tube 30, and thus facilitate the maintenance of the non-uniform distribution state of the hydrogen in the cladding tube 30, so that the simulation of the hydrogen permeation condition of the cladding tube 30 in the reactor is more realistic.
[0064] In some embodiments, the hydrogen permeation method further comprises: S01, after assembling the cladding tube 30 and the heating element 20, placing the cladding tube 30 into the coolant simulation liquid, heating the coolant simulation liquid to a preset temperature, adjusting the heating power of the heating element 20 so that the temperature of the outer surface of the cladding tube 30 is higher than the preset temperature by a preset value, and obtaining the heating power data of the heating element 20 corresponding to the preset temperature of the coolant simulation liquid. In the S4 step, the cladding tube 30 is heated according to the heating power determined in the S01 step. In such embodiments, the real situation in the reactor can be more realistically simulated, and the heating power of the heating element 20 can be controlled.
[0065] The process of simulating the hydrogen permeation condition of the cladding tube 30 in the reactor in the present application is described below with specific examples.
[0066] The cladding tube 30 is placed in the acid solution at room temperature for pickling according to the acid pickling solution (10% HF+45% HNO3+45% H2O) in volume ratio, and the surface of the pickled sample should be bright and uniform. The pickled sample is washed in running water for 20 min.
[0067] The cladding tube 30 and the heating member 20 are assembled so that the cladding tube 30 is sealingly arranged at the radially outer side of the heating member 20, and the cladding tube 30 and the heating member 20 are jointly placed in the accommodating cavity 11. The LiOH solution with a concentration of 1 mol / L is added to the accommodating cavity 11, and the LiOH solution is heated to 325°C by the shell member 10. The heating member 20 is started, and the outer surface temperature of the cladding tube 30 is heated to 345°C. The reaction lasts for 114 hours. The hydrogen distribution in the cladding tube 30 after the reaction is shown in FIGS. 8 and 9. Figure 6 and Figure 7 , Figure 6 and Figure 7 are metallographic micrographs of the hydrogen distribution in the tube wall of the cladding tube after the hydrogen permeation simulation of the cladding tube in the reactor by the hydrogen permeation device according to an embodiment of the present application.
[0068] It can be seen from Figure 6 and Figure 7 that the hydrogen gas is enriched on the side of the cladding tube 30 tube wall close to the radially outer surface, and the hydrogen concentration on this side is relatively high, forming a local hydrogen-rich region. The hydrogen concentration on the side of the cladding tube 30 tube wall close to the radially inner surface is relatively low, and a long strip-shaped hydride structure 80 appears on this side, which is consistent with the hydrogen distribution state in the tube wall of the cladding tube 30 in the reactor. The experimental results prove that the present application can effectively form a non-uniform hydrogen concentration distribution in the tube wall of the cladding tube 30, thereby providing an experimental basis for the performance research of the nuclear reactor fuel cladding under actual operating conditions.
[0069] For the embodiments of the present application, it should also be noted that the embodiments and features in the embodiments of the present application can be combined with each other to obtain new embodiments without conflict.
[0070] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto, and the protection scope of the present application should be subject to the protection scope of the claims.
Claims
1. A hydrogen permeation apparatus for simulating hydrogen permeation conditions of a cladding tube in a reactor, comprising: The hydrogen permeation device comprises: a shell configured to form a containing cavity for containing and heating a coolant simulation liquid; wherein the cladding tube is arranged in the containing cavity, and the coolant simulation liquid in the containing cavity can react with the cladding tube to form hydrogen gas; a heating element for providing heat to simulate fuel in the cladding tube, the cladding tube being sealingly arranged radially outward of the heating element to prevent the coolant simulation liquid from entering the inside of the cladding tube during hydrogen permeation; the heating element is configured to heat the temperature of the outer surface of the cladding tube to be higher than the temperature of the coolant simulation liquid by a preset value, and maintain the preset time while the cladding tube remains sealed.
2. The hydrogen permeation apparatus of claim 1, wherein Further comprising: a resilient buffer arranged between the cladding tube and the heating element, for providing elastic deformation when the heating element thermally expands, to prevent the heating element from pressing the cladding tube.
3. The hydrogen permeation apparatus of claim 2, wherein, The resilient buffer is a metal bellows or a spring.
4. The hydrogen permeation apparatus of claim 1, wherein Further comprising: a first temperature measuring element for measuring the temperature of the outer surface of the cladding tube; a second temperature measuring element for measuring the temperature of the coolant simulation liquid; a control element configured to adjust the heating power of the heating element according to the temperature difference measured by the first temperature measuring element and the second temperature measuring element when the temperature measured by the second temperature measuring element is a preset temperature, so that the temperature difference is the preset value.
5. The hydrogen permeation apparatus of claim 4, wherein Further comprising: a pressure measuring element for measuring the pressure in the containing cavity; the control element adjusts the heating power of the shell according to the pressure measured by the pressure measuring element to increase the pressure in the containing cavity to a preset pressure.
6. The hydrogen permeation apparatus according to any one of claims 1 to 5, wherein Further comprising: at least one partition element for separating a plurality of sub-chambers that are not in communication with each other in the containing cavity; each partition element forms a space for the cladding tube to pass through; the cladding tube passes through each space into each sub-chamber.
7. The hydrogen permeation apparatus according to any one of claims 1 to 5, wherein The coolant simulation liquid is an aqueous solution of lithium hydroxide, and the concentration of lithium hydroxide is 0.8-1.2 mol / L.
8. The hydrogen permeation apparatus according to any one of claims 1 to 5, wherein Further comprising: a sealing element for sealing the axial end of the cladding tube.
9. A hydrogen permeation method for simulating hydrogen permeation conditions of a cladding tube in a reactor, characterized by, The hydrogen permeation method is implemented by using the hydrogen permeation device of any one of claims 1-8, and the hydrogen permeation method comprises: S1, assembling the cladding tube and the heating element so that the cladding tube is sealingly arranged radially outward of the heating element; S2, placing the cladding tube and the heating element together in the containing cavity; S3, adding the coolant simulation liquid to the containing cavity, and heating the coolant simulation liquid to a preset temperature; S4, starting the heating element, heating the temperature of the outer surface of the cladding tube to be higher than the temperature of the coolant simulation liquid to form a temperature difference on the inner and outer sides of the tube wall of the cladding tube, and maintaining the preset time while the cladding tube remains sealed.
10. The hydrogen permeation method according to claim 9, wherein Further comprising: S01, after assembling the cladding tube and the heating element, placing the cladding tube in the coolant simulation liquid, heating the coolant simulation liquid to a preset temperature, adjusting the heating power of the heating element so that the temperature of the outer surface of the cladding tube is higher than the preset temperature by a preset value, to obtain the heating power data of the heating element corresponding to the coolant simulation liquid at the preset temperature; In step S4, the cladding tube is heated according to the heating power determined in step S01. In step S4, the cladding tube is heated according to the heating power determined in step S01.