Temperature measuring device and temperature measuring method for fuel assembly

Abstract

The embodiment of the present application provides a temperature measuring device and a temperature measuring method of a fuel assembly. The temperature measuring device comprises a guide assembly, an internally defined guide channel is formed through the guide assembly, the guide assembly comprises a main pipe, a deflection pipe and a guide joint, the guide joint is defined to form a containing cavity which is matched with an upper end structure of a measured object, so as to cover the upper end of the measured object; and a temperature measuring assembly, comprising a temperature measuring element, the temperature measuring assembly is arranged in the guide channel of the guide assembly and is configured to be axially movable relative to the guide channel, when the guide joint covers the upper end of the measured object, the temperature measuring assembly can be moved downward in the guide channel to make the temperature measuring element enter a channel of the measured object. The deflection pipe is arranged to be able to deflect relative to the main pipe and the guide joint, when the guide joint covers the upper end of the measured object, through the deflection of the deflection pipe, the main pipe can be translated relative to the guide joint in a horizontal direction.

Description

Technical Field

[0001] This application relates to the field of temperature measurement technology, and in particular to a temperature measuring device and a method for measuring the temperature of a fuel assembly. Background Technology

[0002] This section provides background information relevant to this application only and does not necessarily constitute prior art.

[0003] In some cases, it is necessary to obtain the internal temperature of the fuel assemblies within the reactor. For fast reactors, the reactor top cover has a stopcock with measurement channels, through which temperature measuring elements can enter the pressure vessel. However, the measurement channels on the stopcock are typically not aligned with the fuel assemblies inside the pressure vessel, making it difficult to directly measure the internal temperature of the fuel assemblies using existing temperature measuring elements. Summary of the Invention

[0004] A brief overview of this application is provided below to offer a basic understanding of certain aspects thereof. It should be understood that this overview is not an exhaustive summary of the application. It is not intended to identify key or essential parts of the application, nor is it intended to limit its scope. Its purpose is merely to present certain concepts in a simplified form as a prelude to the more detailed description that follows.

[0005] In a first aspect, embodiments of this application provide a temperature measuring device, comprising: a guide assembly internally defining a through guide channel, the guide assembly including a main tube, a deflecting tube, and a guide connector, the deflecting tube connecting the lower end of the main tube and the upper end of the guide connector, the guide connector defining a receiving cavity adapted to the structure of the upper end of an object to be measured, so as to cover the upper end of the object to be measured within it, the object to be measured having a channel extending downward from the upper end; and a temperature measuring assembly including a temperature measuring element, the temperature measuring assembly being disposed within the guide channel of the guide assembly and configured to be axially movable relative to the guide channel, wherein when the guide connector covers the upper end of the object to be measured, the temperature measuring assembly can move downward within the guide channel to allow the temperature measuring element to enter the channel of the object to be measured; wherein the deflecting tube is configured to be deflectable relative to the main tube and the guide connector, so that when the guide connector covers the upper end of the object to be measured, the deflection of the deflecting tube allows the main tube to be translated horizontally relative to the guide connector.

[0006] Secondly, embodiments of this application provide a method for measuring the temperature of a fuel assembly. The method utilizes the apparatus described in the first aspect of this application to measure the temperature of a fuel assembly within a pressure vessel. The pressure vessel includes a stopcock located on a top cover. The stopcock has a temperature measuring channel and a support member located radially outside the temperature measuring channel. The method includes: rotating the stopcock to align the temperature measuring channel with the fuel assembly within the pressure vessel whose temperature is to be measured; connecting a guide assembly to the temperature measuring assembly and a guide sleeve, wherein the deflection tube, the guide joint, and the lower part of the temperature measuring assembly are located within the guide sleeve; and inserting the entire temperature measuring device into the temperature measuring channel and moving it downwards to the abutment portion of the guide sleeve. At the position where it abuts against the support on the cock, disconnect the guide sleeve from the guide assembly, move the guide assembly and temperature sensing assembly downward relative to the guide sleeve so that the guide joint covers the upper end of the temperature sensing assembly; disconnect the temperature sensing assembly from the guide assembly, move the temperature sensing assembly downward relative to the guide assembly so that the temperature sensing element enters the fuel assembly channel until the upper part of the temperature sensing assembly abuts against the positioning groove of the guide assembly; move the guide sleeve upward to the position where the deflection fitting and guide joint extend out of the guide sleeve, and connect the guide sleeve to the guide assembly; turn the cock back to the initial position, at which point the deflection fitting deflects relative to the main fitting and guide joint.

[0007] The temperature measuring device of this application, due to the provision of a deflection tube, allows the main tube to be translated horizontally relative to the guide joint when the guide joint covers the upper end of the object to be measured. This enables the temperature measuring device to be installed on the reactor valve for measuring the temperature of the internal components of the reactor.

[0008] These and other advantages of this application will become more apparent from the following detailed description of preferred embodiments in conjunction with the accompanying drawings. Attached Figure Description

[0009] To further illustrate the above and other advantages and features of this application, the specific embodiments of this application will be described in more detail below with reference to the accompanying drawings. The drawings, together with the following detailed description, are included in and form a part of this specification. Elements having the same function and structure are indicated by the same reference numerals. It should be understood that these drawings only depict typical examples of this application and should not be considered as limiting the scope of this application.

[0010] Figure 1 This is a cross-sectional schematic diagram of a temperature measuring device according to an embodiment of this application;

[0011] Figure 2 yes Figure 1 A partially enlarged schematic diagram of the temperature measuring device shown.

[0012] Figure 3 yes Figure 1 A cross-sectional schematic diagram of the guide assembly of the temperature measuring device shown;

[0013] Figure 4 yes Figure 3 A schematic cross-sectional view of the guide assembly along the AA direction;

[0014] Figure 5 yes Figure 3 A schematic cross-sectional view of the guide assembly along the BB direction;

[0015] Figure 6 yes Figure 1 A cross-sectional schematic diagram of the temperature measuring component of the temperature measuring device shown.

[0016] Figure 7 yes Figure 6 A partially enlarged schematic diagram of the temperature measuring component shown;

[0017] Figure 8 yes Figure 1 A schematic cross-sectional view of the guide sleeve of the temperature measuring device shown.

[0018] Figure 9 yes Figure 8 The diagram shows a cross-sectional view of the guide sleeve along the CC direction.

[0019] Figure 10 It is based on Figure 1 The diagram shows the temperature measuring device in its first operating state.

[0020] Figure 11 It is based on Figure 1 The diagram shows the temperature measuring device in its second operating state.

[0021] Figure 12 It is based on Figure 1 The diagram shows the temperature measuring device in its third operating state.

[0022] Figure 13 It is based on Figure 1 The diagram shows the temperature measuring device in its fourth operating state.

[0023] Figure 14 yes Figure 13 A partially enlarged schematic diagram of the temperature measuring device shown.

[0024] Figure 15 It is based on Figure 1 The diagram shows the temperature measuring device in its fifth operating state.

[0025] Figure 16 yes Figure 15 A partially enlarged schematic diagram of the temperature measuring device shown.

[0026] It should be noted that the accompanying drawings are not necessarily drawn to scale, but are shown only in a schematic manner without affecting the reader's understanding.

[0027] Explanation of reference numerals in the attached figures:

[0028] 10. Guide components; 101. Guide channels;

[0029] 11. Main pipe fitting; 111. Arc-shaped cavity; 112. Limiting groove;

[0030] 12. Deflection fittings;

[0031] 121. Outer tube; 1211. Outer tube body; 12111. Outer tube channel; 12112. Spring cavity; 12113. Slide groove; 1212. Outer tube ball head; 1213. Outer tube connecting section;

[0032] 122. Inner tube; 1221. Inner tube body; 12211. Inner tube channel; 1222. Inner...

[0033] Ball head; 1223, inner tube connection section;

[0034] 123. Elastic components;

[0035] 13. Guide joint; 131. Receiving cavity; 132. Protrusion; 133. Positioning groove; 134. Arc-shaped cavity;

[0036] 14. Support; 141. First positioning hole; 142. Second positioning hole; 140. Arc-shaped sidewall; 1401. Slot; 143. Positioning pin; 144. Positioning pin;

[0037] 15. Connecting flange; 151. Locating hole;

[0038] 16. Sealing ring;

[0039] 17. Sealing ring;

[0040] 20. Guide sleeve; 21. Positioning groove; 22. Protrusion; 221. Through hole; 23. Abutment part;

[0041] 30. Temperature sensing component; 301. Measuring end;

[0042] 31. Upper pipe fitting; 311. Annular positioning groove; 312. Through hole; 313. Set screw; 314. Annular stepped surface;

[0043] 32. Pipe fittings;

[0044] 33. Temperature sensing element;

[0045] 34. Tension spring;

[0046] 35. Positioning and mating parts;

[0047] 36. Lower protective sleeve; 361. Through hole;

[0048] 37. Spring connector;

[0049] 40. Support components;

[0050] 50. Fitting pipe seat;

[0051] 200. The object to be tested. Detailed Implementation

[0052] Exemplary embodiments of this application will be described below with reference to the accompanying drawings. For clarity and brevity, not all features of actual implementations are described in the specification. However, it should be understood that many implementation-specific decisions must be made in the development of any such actual embodiment to achieve the developer's specific goals, such as complying with constraints related to the system and business, and these constraints may vary depending on the implementation. Furthermore, it should be understood that while development work can be very complex and time-consuming, such development work is merely a routine task for those skilled in the art who benefit from the content of this application.

[0053] It should also be noted that, in order to avoid obscuring this application with unnecessary details, only the equipment structure and / or processing steps closely related to the solution according to this application are shown in the accompanying drawings, while other details that are not closely related to this application are omitted.

[0054] It should be noted that, unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning as understood by a person with ordinary skills in the field to which this application pertains.

[0055] In the description of the embodiments of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0056] As mentioned earlier, the measuring channel on the cock is usually not aligned with the fuel assembly inside the pressure vessel, making it difficult to directly measure the internal temperature of the fuel assembly using existing temperature measuring elements.

[0057] To address the aforementioned technical problems, this application provides a temperature measuring device.

[0058] See Figure 1 and Figure 2 The temperature measuring device in this application embodiment includes a guide assembly 10 and a temperature measuring assembly 30.

[0059] See Figure 3 The guide assembly 10 internally defines a through guide channel 101. The guide assembly 10 includes a main tube 11, a deflection tube 12, and a guide joint 13. The deflection tube 12 connects the lower end of the main tube 11 and the upper end of the guide joint 13. The guide joint 13 defines a receiving cavity 131 that is adapted to the upper end structure of the object to be tested 200 so as to cover the upper end of the object to be tested 200. The object to be tested 200 has a channel extending downward from the upper end.

[0060] See Figure 6 and Figure 7 The temperature measuring assembly 30 includes a temperature measuring element 33. The temperature measuring assembly 30 is disposed within the guide channel 101 of the guide assembly 10 and configured to move axially relative to the guide channel 101. When the guide connector 13 covers the upper end of the object to be measured 200, the temperature measuring assembly 30 can move downward within the guide channel 101 to allow the temperature measuring element 33 to enter the channel of the object to be measured 200. In some embodiments,

[0061] See Figure 3 The deflecting fitting 12 is configured to deflect relative to the main fitting 11 and the guide joint 13, so that when the guide joint 13 covers the upper end of the object to be measured 200, the main fitting 11 can be translated horizontally relative to the guide joint 13 by the deflection of the deflecting fitting 12.

[0062] The temperature measuring device of this application embodiment can be installed on the stopcock of a reactor to measure the temperature of internal reactor components. When the stopcock is rotated to align its measuring channel with the component under test, the temperature measuring element 33 can enter the channel of the component under test inside the pressure vessel through the measuring channel on the stopcock. After the stopcock is rotated back to the initial position, the deflection tube 12 is deflected, the main tube 11 is translated relative to the guide joint 13, and the temperature measuring element 33 of the temperature measuring component 30 remains in the channel of the component under test, thereby realizing the temperature measurement of the component under test.

[0063] In some embodiments, see Figure 2 and Figure 3 The lower end of the main pipe fitting 11 forms an arc-shaped cavity 111, and the upper end of the guide joint 13 forms an arc-shaped cavity 134. The deflecting pipe fitting 12 includes an outer pipe 121 and an inner pipe 122, with the inner pipe 122 slidably disposed within the outer pipe 121 along the axial direction. The end of the outer pipe 121 away from the inner pipe 122 forms an outer pipe ball head 1212, and the end of the inner pipe 122 away from the outer pipe 121 forms an inner pipe ball head 1222. The two ball heads are rotatably disposed within their respective arc-shaped cavities. When the deflecting pipe fitting 12 deflects, the positions of the two ball heads remain within the arc-shaped cavities, and the inner pipe 122 and the outer pipe 121 move away from each other, thereby adaptively elongating the length of the deflecting pipe fitting 12.

[0064] In some embodiments, the outer tube 121 forms an axially penetrating outer tube channel 12111. The outer tube 121 sequentially includes an outer tube body 1211, an outer tube connecting section 1213, and an outer tube ball head 1212 along the axial direction. The outer tube body 1211, the outer tube connecting section 1213, and the outer tube ball head 1212 each form an interconnected penetrating channel inside. The diameter of the outer tube connecting section 1213 is smaller than the diameters of the outer tube body 1211 and the outer tube ball head 1212 to avoid interference from the outer tube connecting section 1213 causing the outer tube ball head 1212 to rotate relative to the arcuate cavity 111.

[0065] In some embodiments, the inner tube 122 forms an axially penetrating inner tube channel 12211. The inner tube 122 includes, in sequence along the axial direction, an inner tube body 1221, an inner tube connecting section 1223, and an inner tube ball head 1222. The inner tube body 1221, the inner tube connecting section 1223, and the inner tube ball head 1222 each form an interconnected through channel inside.

[0066] The outer tube body 1211 is further defined with a groove 12113 that communicates with the outer tube channel 12111, and the inner tube body 1221 is slidably disposed in the groove 12113.

[0067] In some embodiments, the deflecting fitting 12 further includes an elastic element 123 disposed on the axial side of the inner tube 122 facing the outer tube 121, for providing a force to the guide joint 13 away from the main fitting 11. When the main fitting 11 translates relative to the guide joint 13 and the deflecting fitting 12 deflects, the elastic element 123 can prevent the guide joint 13 from moving upward with the deflecting fitting 12 to separate from the upper end of the object under test 200.

[0068] The outer tube body 1211 also defines a spring cavity 12112 that connects with the slide groove 12113, and the elastic element 123 is disposed in the spring cavity 12112.

[0069] In some embodiments, the outer tube 121 is connected to the main tube 11, and the inner tube 122 is connected to the guide joint 13. The elastic element 123 may be a compression spring, providing a force to the inner tube 122 away from the outer tube 121. In other embodiments, the outer tube 121 is connected to the guide joint 13, and the inner tube 122 is connected to the main tube 11.

[0070] See Figure 2 and Figure 3 In some embodiments, a positioning groove 133 is formed on the side of the guide joint 13 facing the arcuate cavity 134. See also Figure 2 and Figure 6The temperature measuring component 30 also includes a positioning fitting 35, which is adapted to the shape of the positioning groove 133. When the temperature measuring component 30 moves downward to allow the temperature measuring element 33 to enter the channel of the object to be measured 200, the positioning fitting 35 enters the positioning groove 133 and abuts against the positioning groove 133. After the positioning fitting 35 enters the positioning groove 133 and abuts against the positioning groove 133, the temperature measuring component 30 descends to its final position and cannot continue to descend.

[0071] In some embodiments, the positioning groove 133 may be a conical groove, and the positioning mating member 35 includes a conical surface that mates with the conical groove.

[0072] In some embodiments, see Figure 6 The temperature sensing assembly 30 also includes an upper tube 31, a tension spring 34, and a lower protective sleeve 36. A through hole 361 is formed at the lower end of the lower protective sleeve 36 to allow fluid from the channel of the object under test 200 to enter the interior of the lower protective sleeve 36; a positioning fitting 35 is formed at the upper end of the lower protective sleeve 36. The temperature sensing element 33 extends downward within the upper tube 31 into the lower protective sleeve 36.

[0073] The measuring end 301 of the temperature sensing element 33 can be located at the lower end of the temperature sensing element 33, inside the lower protective sleeve 36. The tension spring 34 is located inside the compression spring 123.

[0074] The tension spring 34 is disposed between the upper pipe fitting 31 and the positioning fitting 35, and is sleeved on the temperature sensing element 33, for providing a force to the positioning fitting 35 to abut against the positioning groove 133. When the deflecting pipe fitting 12 deflects relative to the main pipe fitting 11 and the guide joint 13, the tension spring 34 twists accordingly.

[0075] In this embodiment, when the deflection fitting 12 is not deflected, the adjacent coils of the tension spring 34 are closely arranged, and the tension spring 34 cannot be compressed, thus possessing axial stiffness. Therefore, when the temperature sensing component 30 moves downward relative to the guide sleeve 20, the temperature sensing component 30 will move downward as a whole without compression. When the deflection fitting 12 is deflected, the tension spring 34 twists, protecting the internal temperature sensing element 33 from wear.

[0076] In some embodiments, the temperature sensing element 33 may be a thermocouple.

[0077] The temperature sensing assembly 30 also includes a fitting 32 disposed inside the upper fitting 31 for connection to the upper fitting 31. A temperature sensing element 33 extends downward from inside the fitting 32. See also the following embodiments: Figure 7The lower end of the lower protective sleeve 36 forms a through hole 361 to allow fluid from the channel of the object under test 200 to enter the interior of the lower protective sleeve 36, thereby enabling the temperature sensing element 33 to respond quickly to temperature changes. The lower end face of the lower protective sleeve 36 is closed, and the through hole 361 can be disposed adjacent to the temperature sensing element 33 on the side wall of the lower protective sleeve 36. That is, the temperature sensing element 33 is located in the section of the lower protective sleeve 36 below the through hole 361. When the section of the lower protective sleeve 36 below the through hole 361 is filled with fluid, the fluid flows upward after flowing through the through hole 361, avoiding affecting the temperature sensing element 33.

[0078] In some embodiments, see Figure 3 The portion of the main tube 11 located above the arc-shaped cavity 111 forms a limiting groove 112 that is adapted to the lower end of the upper tube 31. The temperature measuring component 30 can move downward within the main tube 11 to the position where the lower end of the upper tube 31 abuts against the limiting groove 112, thereby enabling the temperature measuring component 30 to be supported by the main tube 11.

[0079] In some embodiments, see Figure 6 The upper pipe fitting 31 is provided with an annular positioning groove 311. The guide assembly 10 also includes a connecting flange 15 and a plurality of positioning pins (not shown in the figure). The connecting flange 15 is connected to the top end of the main pipe fitting 11. See Figure 4 The connecting flange 15 is provided with a plurality of radially extending locating holes 151. See also Figure 10 and Figure 11 When the temperature measuring element 33 of the temperature measuring assembly 30 is located inside the main tube 11, the temperature measuring assembly 30 is connected to the main tube 11 by passing each positioning pin through a corresponding positioning hole 151 into the annular positioning groove 311. At this time, the temperature measuring assembly 30 can move together with the guide assembly 10.

[0080] In some embodiments, see Figure 6 and Figure 7 The lower end of the peripheral wall of the upper pipe fitting 31 forms an annular stepped surface 314 coaxial with the upper pipe fitting 31. The temperature measuring assembly 30 also includes a spring connector 37, disposed at the annular stepped surface 314 of the upper pipe fitting 31. A threaded groove is formed on the radial outer surface of the spring connector 37, and the upper end of the tension spring 34 is disposed in the threaded groove, clamped by the peripheral wall of the upper pipe fitting 31 and the spring connector 37 to prevent the tension spring 34 from disengaging.

[0081] In some embodiments, the peripheral wall of the upper tube 31 forms a plurality of through holes 312, and the temperature measuring assembly 30 further includes a plurality of set screws 313 disposed in the plurality of through holes 312 for pressing against the upper end of the tension spring 34 to further prevent the tension spring 34 from disengaging.

[0082] The lower end of the tension spring 34 is connected to the positioning and fitting part 35.

[0083] In some embodiments, see Figure 1 The temperature measuring device also includes a guide sleeve 20, disposed radially outside the main pipe fitting 11, the deflection pipe fitting 12, and the guide joint 13. See also... Figures 10 to 13 The guide sleeve 20 can be moved axially relative to the guide assembly 10 so that the deflecting pipe 12 and the guide joint 13 are located inside the guide sleeve 20, or so that the deflecting pipe 12 and the guide joint 13 extend downward to the outside of the guide sleeve 20.

[0084] Specifically, see Figure 12 and Figure 13 When the guide joint 13 covers the upper end of the object to be measured 200, the guide sleeve 20 can move upward so that the deflection pipe 12 extends downward out of the guide sleeve 20.

[0085] The lower part of the main pipe fitting 11, the deflection pipe fitting 12, and the guide joint 13 can all be located inside the guide sleeve 20 so that the guide sleeve 20 provides a guiding function.

[0086] It is easy to understand that, since the guide joint 13 and the deflecting tube 12 are engaged by an arcuate groove and a ball head, the guide joint 13 can rotate relative to the deflecting tube 12. In some embodiments, the guide joint 13 may be provided with a radially outward protrusion 132, which can be clearance-fitted with the inner wall of the guide sleeve 20. When the guide assembly 10 moves downward relative to the guide sleeve 20, the protrusion 132 can prevent the guide joint 13 from rotating.

[0087] In some embodiments, see Figure 1 and Figure 3 The guide assembly 10 further includes a support 14, which is connected to the main tube 11 radially outward. The upper end of the guide sleeve 20 is slidably located radially inward of the support 14. The support 14 has a first positioning hole 141 at its upper part and a second positioning hole 142 at its lower part; see also Figure 8 The upper end of the guide sleeve 20 is provided with a positioning groove 21, see [reference]. Figure 13 When the guide sleeve 20 moves upward to the position where the deflecting pipe 12 extends downward from the guide sleeve 20, the guide sleeve 20 and the support 14 are positioned by the positioning pin 143 which is sequentially inserted into the first positioning hole 141 and the positioning groove 21.

[0088] See Figure 10When the guide sleeve 20 moves axially simultaneously with the main pipe 11 and the temperature measuring component 30, the guide sleeve 20 and the support 14 are positioned by the positioning pins 144, which are sequentially inserted into the second positioning hole 142 and the positioning groove 21. The positioning pins 144 and 143 can be the same positioning pin.

[0089] In some embodiments, the positioning groove 21 is located below the abutment portion 23.

[0090] See Figure 5 In some embodiments, the support 14 includes two opposing arcuate sidewalls 140, with a slot 1401 formed between the two arcuate sidewalls 140. A first positioning hole 141 and a second positioning hole 142 are formed on the arcuate sidewalls 140. See also Figure 8 and Figure 9 Two protrusions 22 extend radially outward from the circumferential sidewall of the guide sleeve 20 below the positioning groove 21. The two protrusions 22 are positioned opposite each other and are used for lifting the guide sleeve 20. Each of the two protrusions 22 is located in a slot 1401, thereby allowing the guide sleeve 20 to move axially relative to the support 14. The protrusions 22 have through holes 221 for mounting lifting components.

[0091] In some embodiments, the object under test 200 is a component inside a pressure vessel, see [reference needed]. Figure 8 and Figure 10 The guide sleeve 20 also includes an abutment portion 23 for abutting against a support member 40 disposed on the stopcock, so that the support member 40 supports the guide sleeve 20. In some embodiments, the abutment portion 23 may be a flange. The support member 40 is disposed radially outside the measuring channel of the stopcock.

[0092] In use, when the entire temperature measuring device is inserted into the measuring channel of the stopcock, the lower part of the main tube 11, the deflection tube 12, and the guide joint 13 are located inside the guide sleeve 20. When the guide sleeve 20 descends to the point where the abutment part 23 abuts against the support member 40, the entire temperature measuring device is supported by the support member 40.

[0093] When the support 14 moves downward a predetermined distance relative to the guide sleeve 20, the lower end of the support 14 is supported by the support member 40 on the stopcock. The lower part of the guide joint 13 is located outside the guide sleeve 20 and covers the upper end of the object to be tested 200, abutting against the upper end of the object to be tested 200. Due to a certain amount of eccentricity during actual installation, the axis of the guide joint 13 and the channel at the upper end of the object to be tested 200 cannot be completely aligned. In order to avoid the guide joint 13 not abutting against the upper end of the object to be tested 200 when the upper end is covered, in this embodiment, when the guide sleeve 20 moves down to abut against the support member 40 on the stopcock, it does not go directly down to the position where the guide joint 13 abuts against the upper end of the object to be tested 200. Instead, by moving the guide assembly 10 downward relative to the guide sleeve 20, the lower part of the guide joint 13 is exposed above the guide sleeve 20. Then, by deflecting relative to the deflecting pipe 12, the upper end of the object to be tested 200 can be covered inside and abut against the upper end of the object to be tested 200.

[0094] In some embodiments, the temperature measuring device further includes: a mating tube seat 50 disposed on the radially outer side of the guide sleeve 20, the mating tube seat 50 being used to connect with the support member 40 on the valve, and the guide sleeve 20 abutting against the mating tube seat 50.

[0095] In such an embodiment, the abutting portion 23 of the guide sleeve 20 abuts against the mating seat 50, so as to support the guide sleeve 20 by the mating seat 50 and the support member 40.

[0096] In some embodiments, the mating tube seat 50 may also be provided with a positioning hole, and the guide sleeve 20 is provided with another positioning groove below the positioning groove 21, for connecting the mating tube seat 50 and the guide sleeve 20 into one unit by means of a positioning pin. When the temperature measuring device descends as a whole relative to the measuring channel of the valve stem until the mating tube seat 50 abuts against the support member 40, the mating tube seat 50 and the support member 40 are connected by fasteners, and the positioning pin connecting the mating tube seat 50 and the guide sleeve 20 is removed.

[0097] See Figure 1 The upper end of the upper pipe fitting 31 is a sealed end, and the temperature sensing element 33 is connected to the power supply and processing system through the upper end of the upper pipe fitting 31.

[0098] To ensure the airtightness of the pressure vessel, a sealing ring 16 is provided between the guide sleeve 20 and the main pipe fitting 11, and a sealing ring 17 is provided between the main pipe fitting 11 and the temperature measuring component 30.

[0099] Multiple sealing rings 16 can be provided between the guide sleeve 20 and the main pipe fitting 11; multiple sealing rings 17 can be provided between the main pipe fitting 11 and the upper pipe fitting 31.

[0100] This application also provides a method for measuring the temperature of a fuel assembly. The method utilizes a temperature measuring device from any embodiment of this application to measure the temperature of the fuel assembly within a pressure vessel. The pressure vessel includes a stopcock located on a top cover, the stopcock having a measuring channel and a support member 40 located radially outside the measuring channel. The temperature measurement method includes steps S1 to S7.

[0101] Step S1: Rotate the stopcock to align the measuring channel with the fuel assembly whose temperature is to be measured inside the pressure vessel.

[0102] Step S2: Connect the guide assembly 10 to the temperature measuring assembly 30 and the guide sleeve 20 respectively. At this time, the deflection pipe 12, the guide joint 13 and the lower part of the temperature measuring assembly 30 are located inside the guide sleeve 20.

[0103] See Figure 10 In step S2, the positioning pin 143 is passed through the first positioning hole 141 of the support 14 and enters the positioning groove 21 of the guide sleeve 20, thereby connecting the guide assembly 10 to the guide sleeve 20. The positioning pin is passed through the positioning hole 151 of the connecting flange 15 and enters the annular positioning groove 311 of the upper pipe fitting 31, thereby connecting the guide assembly 10 to the temperature measuring assembly 30.

[0104] Step S3: Insert the entire temperature measuring device into the measuring channel and move it downwards until the abutment part 23 of the guide sleeve 20 abuts against the support member 40 on the stopcock.

[0105] During the overall downward movement of the temperature measuring device, the guide sleeve 20 provides guidance for the lowering of the guide assembly 10 and also serves as a limit to prevent the guide joint 13 from colliding with the head of the fuel assembly and rotating during the lowering process, so that the guide joint 13 cannot cover the head of the assembly.

[0106] Step S4: Disconnect the guide sleeve 20 from the guide assembly 10, and move the guide assembly 10 and the temperature measuring assembly 30 downward relative to the guide sleeve 20 so that the guide joint 13 covers the upper end of the fuel assembly.

[0107] In step S4, the positioning pin 143 is removed from the first positioning hole 141 of the support 14 and the positioning groove 21 of the guide sleeve 20, thereby disconnecting the guide sleeve 20 from the guide assembly 10.

[0108] See Figure 11 After the guide sleeve 20 is lowered into place, the guide assembly 10 is lowered. The protrusion 132 matches the inner diameter of the guide sleeve 20, so that the guide joint 13 will not rotate during the lowering of the guide assembly 10, and can be smoothly fitted into the head of the fuel assembly, providing guidance for the lower protective sleeve 36 to be inserted into the fuel assembly.

[0109] It is easy to understand that during the process of lowering the guide assembly 10, initially due to gravity, the inner tube body 1221 is located below the outer tube 121. After the guide joint 13 is fitted onto the head of the fuel assembly, the outer tube 121 continues to be lowered while the inner tube 122 remains stationary, thereby compressing the spring 123 and providing a clamping force for the guide assembly 10 to press down on the head of the fuel assembly.

[0110] Step S5: Disconnect the temperature measuring component 30 from the guide component 10, and move the temperature measuring component 30 downward relative to the guide component 10 so that the temperature measuring element 33 enters the channel of the fuel assembly until the upper tube 31 of the temperature measuring component 30 abuts against the positioning groove 133 of the guide component 10.

[0111] In step S5, the positioning pin is removed from the positioning hole 151 of the connecting flange 15 and the annular positioning groove 311 of the upper pipe fitting 31, thereby disconnecting the temperature measuring component 30 from the guide component 10.

[0112] After the guide joint 13 is fitted onto the head of the fuel assembly, the temperature sensing component 30 is lowered. (See also...) Figure 1 , Figure 2 and Figure 12 The lower protective sleeve 36 is inserted into the fuel assembly under the guidance of the guide component 10, the positioning fitting 35 enters the positioning groove 133, the upper pipe 31 falls on the positioning groove 133, and the temperature measuring component 30 is supported by the guide component 10.

[0113] Step S6: Move the guide sleeve 20 upward to a position where the deflection fitting 12 and the guide connector 13 extend outside the guide sleeve 20, and connect the guide sleeve 20 to the guide assembly 10.

[0114] See Figure 13 and Figure 14 In step S6, the positioning pin 144 is passed through the second positioning hole 142 of the support 14 and enters the positioning groove 21 of the guide sleeve 20, thereby connecting the guide assembly 10 to the guide sleeve 20. Before rotating the cock, the guide sleeve 20 can be raised to a position where its lower end is close to the lower surface of the cock.

[0115] Step S7: Turn the stopcock to the initial position. At this time, the deflection fitting 12 deflects relative to the main fitting 11 and the guide joint 13.

[0116] See Figure 15 and Figure 16The rotating cock and guide connector 13 are fixed on the head of the fuel assembly. The inner tube ball head 1222 of the inner tube 122 rotates in the arc cavity 134, while the outer tube ball head 1212 of the outer tube 121 rotates in the arc cavity 111 of the main tube 11. At the same time, the inner tube body 1221 moves relative to the outer tube 121 in the groove 12113 of the outer tube 121, providing the elongation required by the guide assembly 10 during rotation. The groove 12113 restricts the range of motion of the inner tube body 1221.

[0117] Because the guide assembly 10 and the temperature measuring assembly 30 can deflect within the reactor core in coordination with the rotation of the reactor valve, the temperature measuring device of this embodiment can achieve online measurement of the internal temperature of the fast reactor fuel assembly, thereby enabling real-time monitoring of the internal temperature of the fuel assembly in the required scenarios. The temperature measuring device can deflect within the reactor core as the reactor valve rotates, thereby enabling monitoring of the internal temperature of the fuel rod bundle directly below the measurement channel and in adjacent areas, thus improving the safety and reliability of temperature measurement in scenarios requiring monitoring of the internal temperature of the fast reactor, such as natural circulation experiments.

[0118] Regarding the embodiments of this application, it should also be noted that, without conflict, the embodiments of this application and the features in the embodiments can be combined with each other to obtain new embodiments.

[0119] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. The scope of protection of this application shall be determined by the scope of the claims.

Claims

1. A temperature measuring device, comprising: A guide assembly, internally defining a through guide channel, the guide assembly includes a main tube, a deflection tube, and a guide joint, the deflection tube connects the lower end of the main tube and the upper end of the guide joint, the guide joint defines a receiving cavity adapted to the upper end structure of the object under test, so as to cover the upper end of the object under test, the object under test having a channel extending downward from the upper end. and A temperature measuring assembly, including a temperature measuring element, is disposed within the guide channel of the guide assembly and configured to be axially movable relative to the guide channel. When the guide connector covers the upper end of the object to be measured, the temperature measuring assembly can move downward within the guide channel to allow the temperature measuring element to enter the channel of the object to be measured. The deflecting tube is configured to deflect relative to the main tube and the guide joint, so that when the guide joint covers the upper end of the object to be tested, the deflection of the deflecting tube allows the main tube to translate horizontally relative to the guide joint. The lower end of the main pipe and the upper end of the guide joint respectively form arc-shaped cavities; The guide joint has a positioning groove on the side facing the arc-shaped cavity; The temperature measuring component also includes: The positioning fitting is configured such that when the temperature measuring component moves downward to allow the temperature measuring element to enter the channel of the object to be measured, the positioning fitting enters the positioning groove and abuts against the positioning groove. The temperature measuring component also includes: Upper pipe fittings; A lower protective sleeve, wherein a through hole is formed at the lower end of the lower protective sleeve to allow fluid within the channel of the object to be measured to enter the interior of the lower protective sleeve; a positioning fitting is formed at the upper end of the lower protective sleeve; and a temperature sensing element extends downward into the lower protective sleeve within the upper fitting; and A tension spring is disposed between the upper tube and the positioning fitting, and is sleeved on the temperature sensing element, for providing a force to the positioning fitting to abut against the positioning groove; When the deflecting pipe is deflected relative to the main pipe and the guide joint, the tension spring is twisted accordingly to protect the internal temperature sensing element from wear. When the deflection fitting does not deflect, the adjacent coils of the tension spring are closely arranged, and the tension spring cannot be compressed.

2. The apparatus of claim 1, wherein the deflecting tube comprises: An outer tube and an inner tube, wherein the inner tube is slidably disposed within the outer tube along the axial direction; The outer tube's end away from the inner tube and the inner tube's end away from the outer tube are respectively formed into ball heads, which are rotatably disposed within the corresponding arc-shaped cavities.

3. The apparatus according to claim 2, wherein, The deflection fitting further includes an elastic element disposed on the axial side of the inner tube facing the outer tube, for providing a force to the guide joint away from the main fitting.

4. The apparatus according to claim 2, wherein, The positioning fitting is adapted to the shape of the positioning groove.

5. The apparatus according to claim 1, wherein, The lower end of the lower protective sleeve has a through hole to allow fluid in the channel of the object under test to enter the interior of the lower protective sleeve.

6. The apparatus according to claim 1, wherein, The portion of the main tube above the arc-shaped cavity forms a limiting groove that fits the lower end of the upper tube. The temperature measuring component can move downward within the main tube until the lower end of the upper tube abuts against the limiting groove.

7. The apparatus according to claim 6, wherein, The upper pipe fitting is provided with an annular positioning groove; The guiding component also includes: A connecting flange is provided, which is connected to the top end of the main pipe fitting. The connecting flange is provided with a plurality of positioning holes extending radially. Multiple positioning pins, When the temperature measuring element of the temperature measuring assembly is located inside the main tube, the temperature measuring assembly is connected to the main tube by passing each of the positioning pins through a corresponding positioning hole into the annular positioning groove.

8. The apparatus according to claim 1, wherein, The lower end of the peripheral wall of the upper pipe fitting forms an annular stepped surface coaxial with the upper pipe fitting; The temperature measuring component also includes: A spring connector is disposed at the annular stepped surface of the upper tube. A threaded groove is formed on the radial outer surface of the spring connector. The upper end of the tension spring is disposed in the threaded groove and is clamped by the peripheral wall of the upper tube and the spring connector.

9. The apparatus according to claim 8, wherein, The peripheral wall of the upper pipe has multiple through holes, and the temperature measuring component also includes multiple set screws disposed in the multiple through holes for pressing against the upper end of the tension spring.

10. The apparatus according to claim 1, wherein, The temperature sensing element is a thermocouple.

11. The apparatus according to any one of claims 1-10, further comprising: A guide sleeve is disposed radially outside the main pipe, the deflecting pipe, and the guide joint. The guide sleeve is axially movable relative to the guide assembly so that the deflecting pipe and the guide joint are located inside the guide sleeve, or so that the deflecting pipe and the guide joint extend downward to the outside of the guide sleeve.

12. The apparatus according to claim 11, wherein, The guiding component also includes: A support is connected to the main pipe fitting radially outward; The upper end of the guide sleeve is slidably located radially inside the support along the axial direction; The upper part of the support is provided with a first positioning hole, and the lower part is provided with a second positioning hole; The upper end of the guide sleeve is provided with a positioning groove. When the guide sleeve moves upward to the position where the deflecting pipe extends downward from the guide sleeve, the guide sleeve and the support are positioned by positioning pins that are sequentially inserted into the first positioning hole and the positioning groove. When the guide sleeve, the main pipe and the temperature measuring component move axially simultaneously, the guide sleeve and the support are positioned by the positioning pins that are sequentially inserted into the second positioning hole and the positioning groove.

13. The apparatus according to claim 12, wherein, The support includes two opposing arc-shaped sidewalls, with a slot formed between the two arc-shaped sidewalls; The first positioning hole and the second positioning hole are formed on the arc-shaped sidewall; Two protrusions are formed below the positioning groove, extending radially outward from the circumferential sidewall of the guide sleeve. The two protrusions are arranged opposite to each other and are used to suspend the guide sleeve. The two protrusions are each located in one of the slots.

14. The apparatus according to claim 12, wherein, When the guide sleeve mates with a structural member disposed on the stopcock so that the guide sleeve is supported by the structural member, the main tube, the deflection tube, and the guide connector are located inside the guide sleeve; When the support moves downward a predetermined distance relative to the guide sleeve, the lower end of the support is supported by the structural components on the stopcock, the lower part of the guide joint is located outside the guide sleeve, and the upper end of the object to be tested is covered inside.

15. The apparatus according to claim 11, wherein, A sealing ring is provided between the guide sleeve and the main tube, and a sealing ring is provided between the main tube and the temperature measuring component.

16. The apparatus according to claim 11, wherein, The object to be tested is a component inside a pressure vessel. The guide sleeve also includes an abutment portion for engaging with a support member disposed on the valve, so that the support member supports the guide sleeve.

17. The apparatus of claim 11, further comprising: A mating tube seat is disposed on the radial outer side of the guide sleeve. The mating tube seat is used to connect with the support on the valve stem, and the guide sleeve abuts against the mating tube seat.

18. A method for measuring the temperature of a fuel assembly, comprising measuring the temperature of a fuel assembly within a pressure vessel using the apparatus as described in any one of claims 1-17, the pressure vessel comprising a stopcock located on a top cover, the stopcock having a temperature measuring channel and a support member located radially outside the temperature measuring channel, the method comprising: Rotate the valve to align the temperature measurement orifice with the fuel assembly inside the pressure vessel at the temperature to be measured; The guide assembly is connected to the temperature measuring assembly and the guide sleeve respectively. At this time, the deflection pipe, the guide joint and the lower part of the temperature measuring assembly are located inside the guide sleeve. Insert the entire temperature measuring device into the temperature measuring channel and move it downwards until the abutment portion of the guide sleeve abuts against the support member on the stopcock. Disconnect the guide sleeve from the guide assembly, and move the guide assembly and the temperature measuring assembly downward relative to the guide sleeve so that the guide joint covers the upper end of the fuel assembly. Disconnect the temperature measuring component from the guide component, and move the temperature measuring component downward relative to the guide component so that the temperature measuring element enters the channel of the fuel assembly until the upper part of the temperature measuring component abuts against the positioning groove of the guide component. Move the guide sleeve upwards to a position where the deflecting pipe and guide joint extend outside the guide sleeve, and connect the guide sleeve to the guide assembly; Turn the stopcock back to its initial position, at which point the deflecting fitting deflects relative to the main fitting and the guide connector.

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