Heating device and nuclear main pump impeller dismounting device with same

Abstract

This invention belongs to the field of nuclear power plant maintenance technology, and more specifically, relates to a heating device and a nuclear main pump impeller disassembly device having the same. The heating device includes a base, a mounting base, and a heating assembly. The base has a positioning cavity into which the pump shaft can be inserted, thereby achieving a positioning connection of the heating device. This allows the device to maintain a relatively accurate and stable positional relationship with the impeller hub at a preset position, providing a foundation for the heating assembly to position and heat the impeller hub. The heating assembly is installed outside the positioning cavity and fixed to the base by the mounting base. The heating assembly includes a combustion head, and when the base is connected to the pump shaft, the nozzle of the combustion head faces the impeller hub. Thus, by using this heating device, the impeller hub can be heated. The impeller hub expands due to heat, thereby reducing the tightness of its interference fit with the pump shaft, enabling smooth impeller disassembly. This improves impeller disassembly efficiency, and the disassembly operation does not damage the impeller or pump shaft, making the disassembly operation safer and more reliable.

Description

Technical Field

[0001] This application belongs to the field of nuclear power plant maintenance technology, and more specifically, it relates to a heating device and a nuclear main pump impeller disassembly device having the same. Background Technology

[0002] The reactor coolant pump in the primary loop system of a nuclear power plant, also known as the main nuclear pump, is a key piece of equipment in the primary loop system. Its main function is to drive the reactor coolant to circulate in the primary loop system. After the coolant absorbs heat in the reactor core, it is driven by the coolant pump to transfer the heat to the steam generator, which in turn transfers the heat to the water in the secondary loop to generate steam for power generation.

[0003] The impeller and pump shaft of the nuclear main pump are usually designed with a tapered interference fit. After long-term operation, the impeller keyway and hub are prone to irregular deformation, making them impossible to disassemble at room temperature. Summary of the Invention

[0004] The purpose of this application is to provide a heating device and a nuclear main pump impeller disassembly device having the same, for efficient and safe separation of the impeller and pump shaft of the nuclear main pump.

[0005] To achieve the above objectives, the technical solution adopted in this application is:

[0006] A heating device is provided for heating the impeller hub during the disassembly of the impeller of a nuclear main pump, comprising:

[0007] The base has a positioning cavity with at least one open end, which is used for the insertion of the pump shaft adapter of the nuclear main pump;

[0008] Mounting base, mounted on the base, the mounting base has a mounting part located outside the positioning cavity;

[0009] A heating assembly is provided on a mounting base. The heating assembly includes at least one burner head mounted on the mounting portion. The heating assembly also includes an ignition element and a gas supply line. The gas supply line is used to connect the burner head and a gas supply device that provides combustible gas. The ignition element is used to ignite the combustible gas entering the burner head to burn.

[0010] The burner head has a nozzle that protrudes from the surface of the mounting part facing the positioning cavity and is used to spray out combustible gas.

[0011] In some embodiments, the heating assembly includes a plurality of combustion heads, which are evenly spaced on the mounting portion and arranged around the positioning cavity.

[0012] In some embodiments, the heating assembly includes seven combustion heads, which, when the base is fitted onto the pump shaft, correspond one-to-one with the positions of the seven blades of the hub.

[0013] In some embodiments, the combustion head may include a main body and a flame nozzle, with a flame outlet disposed on the flame nozzle, the flame nozzle being movably connected to the main body, and the flame nozzle being able to move relative to the main body to adjust the flame ejection angle of the flame outlet.

[0014] In some embodiments, the base has a first end and a second end disposed opposite to each other along a first direction, the opening of the positioning cavity is disposed at the first end, the mounting base is mounted at the second end, and the flame nozzle is disposed facing the first end.

[0015] In some embodiments, the first end is further provided with a positioning part, the opening of the positioning cavity is provided in the positioning part, when the pump shaft is inserted into the positioning cavity, the positioning part is used to adapt and abut against the hub of the impeller sleeved on the pump shaft, and the flame nozzle is located between the positioning part and the mounting part.

[0016] In some embodiments, the mounting portion is provided with a plug-in hole for the burner head to be fitted and inserted, the plug-in hole extending through the mounting portion in a first direction, and the flame nozzle extending out from the plug-in hole in the first direction.

[0017] In some embodiments, the burner head has an air inlet for supplying removable gas, and the gas supply line includes a main pipe and at least one distribution pipe. The main pipe is mounted on a mounting base and has at least one air outlet. The inlet and outlet of the distribution pipe are connected in a one-to-one correspondence, and the outlet of the distribution pipe is connected to the air inlet.

[0018] In some embodiments, the mounting base includes a first mounting plate and a second mounting plate spaced apart, a mounting part is disposed on the first mounting plate, the second mounting plate is disposed on the side of the first mounting plate opposite to the opening of the positioning cavity, and an air supply line is installed on the second mounting plate.

[0019] In some embodiments, the heating device further includes a flow control valve, which is installed on the main pipe or distribution pipe and is used to control the flow rate of the combustible gas.

[0020] In some embodiments, the heating device further includes a gas leakage detection module, which is mounted on a second mounting plate and used to detect the presence of free combustible gas in the environment.

[0021] In some embodiments, the heating device further includes a temperature sensor mounted on a second mounting plate and used to detect the temperature of the wheel hub.

[0022] Another technical solution adopted in this application also provides a nuclear main pump impeller disassembly device, which includes an isolation cover and the aforementioned heating device. The isolation cover is used to surround and shield the impeller from the periphery, and the flame nozzle extends into the isolation cover.

[0023] The beneficial effects of the heating device provided in this application are as follows: The heating device provided in the embodiments of this application can be used to directionally heat the impeller hub. By heating the impeller hub, it causes it to expand, thereby reducing the tightness between the impeller and the pump shaft when they are in a taper interference fit, thus enabling the smooth disassembly of the impeller. Specifically, the heating device includes a base, a mounting base, and a heating assembly. The base has a positioning cavity that can be fitted and inserted into the pump shaft, allowing the pump shaft to be inserted into the positioning cavity. This enables the heating device to be positioned and connected, maintaining a relatively accurate and stable positional relationship with the hub at a preset location. This provides a foundation for the heating assembly to position and heat the hub. The heating assembly is installed outside the positioning cavity and fixed to the base via the mounting base. The heating assembly includes a burner head. When the base is connected to the pump shaft, the nozzle of the burner head faces the hub. At this time, the combustible gas entering the burner head is ignited to form a heating flame. The flame is ejected from the nozzle towards the hub, which can quickly and centrally heat the hub. Utilizing the principle of thermal expansion and contraction, the hub expands when heated, increasing its inner diameter and reducing the interference fit between it and the pump shaft. This reduces the clamping force, allowing the impeller to be disassembled from the pump shaft. The impeller disassembly efficiency is improved, and the disassembly operation will not damage the impeller and pump shaft. The disassembly operation is safer and more reliable, and it also provides better support and protection for subsequent hydraulic component refurbishment. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the structure of the heating device provided in the embodiments of this application;

[0026] Figure 2 for Figure 1 Another perspective view of the heating device shown;

[0027] Figure 3 for Figure 1 Another perspective view of the heating device shown;

[0028] Figure 4 For along Figure 3 A cross-sectional view along line AA in the middle.

[0029] The following are the labeling elements in the figure:

[0030] 10. Base; 11. Positioning cavity; 12. Positioning part;

[0031] 20. Mounting base; 21. Mounting part; 211. Socket; 22. First mounting plate; 23. Second mounting plate; 24. Lifting ring;

[0032] 30. Heating component; 31. Burner head; 311. Flame nozzle; 312. Main body; 313. Flame head; 314. Air inlet; 33. Air supply pipeline; 331. Main pipe; 332. Distribution pipe;

[0033] 40. Leakage detection module; 50. Flow control valve. Detailed Implementation

[0034] To make the technical problem to be solved, the technical solution and the beneficial effects of this application clearer, the following is in conjunction with the appendix. Figures 1 to 4 The present application will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the scope of the present application.

[0035] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0036] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0037] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, "multiple sets" means two or more sets, "multiple pieces" means two or more pieces, and "several" means one or more, unless otherwise explicitly specified.

[0038] The reactor coolant pump in the primary loop system of a nuclear power plant, also known as the main nuclear pump, is a key piece of equipment in the primary loop system. Its main function is to drive the reactor coolant to circulate in the primary loop system. After the coolant absorbs heat in the reactor core, it is driven by the coolant pump to transfer the heat to the steam generator, which in turn transfers the heat to the water in the secondary loop to generate steam for power generation.

[0039] Typically, nuclear power plant main pumps require a complete hydraulic component overhaul after a certain number of years of service, such as 30 years. Disassembling the main pump impeller is the starting and critical step in this overhaul; if the impeller cannot be disassembled, the hydraulic components cannot be disassembled, and subsequent overhauling cannot proceed. The impeller and pump shaft of a nuclear power plant main pump use a tapered interference fit. After long-term operation in the primary loop environment of high temperature, high pressure, and high radiation, the impeller hub and keyway will undergo irregular deformation, making disassembly at room temperature impossible. Traditional mechanical disassembly methods easily cause scoring on the mating surfaces of the impeller and pump shaft, affecting subsequent overhauling.

[0040] In related technologies, the impeller can be disassembled by heating the hub. During disassembly, the impeller hub expands due to heat, increasing the diameter of the mounting hole for the pump shaft, allowing the pump shaft to separate from the hub. However, because the impeller of the nuclear main pump has a multi-bladed (e.g., 7 blades) extended closed structure, the hub where the impeller mates with the pump shaft is located within the internal space of the blades. Conventional electrical heating devices, such as wound electric heaters, are difficult to wind onto the hub, making heating challenging and unsuitable for effective heating. Therefore, there is an urgent need for a highly efficient and safe heating device to heat the impeller hub during the disassembly of the nuclear main pump during nuclear power plant maintenance.

[0041] Based on this, embodiments of this application provide a heating device and a nuclear main pump impeller disassembly device having the same, to solve the above problems.

[0042] Please refer to the following: Figures 1 to 4 The heating device provided in this application embodiment is applicable to, but not limited to, the field of nuclear power plant maintenance, and is used to heat the impeller hub when disassembling the impeller of the nuclear main pump. In this application embodiment, the first direction is the direction shown by arrow F1 in the figure, wherein the axial direction of the pump shaft is in the same direction as the first direction.

[0043] In the embodiments of this application, such as Figures 1 to 4As shown, the heating device is used to heat the impeller hub when disassembling the impeller of the nuclear main pump. The heating device includes a base 10, a mounting base 20, and a heating assembly 30. The base 10 has a positioning cavity 11 with at least one open end for inserting the pump shaft of the nuclear main pump. The mounting base 20 is mounted on the base 10 and has a mounting portion 21 outside the positioning cavity 11. The heating assembly 30 is mounted on the mounting base 20 and includes at least one burner head 31 mounted on the mounting portion 21. The heating assembly 30 also includes an ignition element and a gas supply line 33. The gas supply line 33 is used to connect the burner head 31 and a gas supply device for providing combustible gas. The ignition element is used to ignite the combustible gas entering the burner head 31. The burner head 31 has a nozzle 311 that protrudes from the surface of the mounting portion 21 facing the opening of the positioning cavity 11 and is used to spray out the combustible gas.

[0044] In the embodiments of this application, such as Figure 1 and Figure 4 As shown, the heating device includes a base 10, which is used to achieve precise positioning of the heating device and the pump shaft. The base 10 has a positioning cavity 11 with an opening for the pump shaft to be inserted. Understandably, the pump shaft of the nuclear main pump is a fixed component, the impeller is fitted onto the pump shaft, and the hub is located at the connection between the pump shaft and the impeller. Thus, by inserting the pump shaft into the positioning cavity 11, the base 10 can be stably fixed on the pump shaft, ensuring that the position of the entire heating device does not shift relative to the hub.

[0045] Among them, such as Figure 1 and Figure 4 As shown, "at least one end of the positioning cavity 11 is open" means that the positioning cavity 11 may have one opening for insertion of the pump shaft, or the positioning cavity 11 may have two openings, at least one of which is for insertion of the pump shaft. Exemplarily, the positioning cavity 11 has one opening through which the pump shaft is inserted, or the positioning cavity 11 has two opposing openings along the axial direction of the pump shaft, through which the pump shaft can be inserted. It is understood that when the pump shaft is inserted into the base 10, the impeller is mounted on the pump shaft; therefore, "pump shaft insertion into the positioning cavity 11" means that the end of the pump shaft facing away from the impeller is inserted into the positioning cavity 11, and the heating device is located in the space above the impeller along the axial direction of the pump shaft.

[0046] like Figure 1As shown, the heating device also includes a mounting base 20, which supports the heating component 30 and defines the heating range. Specifically, the mounting base 20 is mounted on the base 10 and has a mounting portion 21 located outside the positioning cavity 11. Since the hub is fitted on the pump shaft (i.e., the outer periphery of the pump shaft located outside the positioning cavity 11), the position design of the mounting portion 21 (outside the positioning cavity 11) allows the heating component 30 to be precisely aligned with the hub, avoiding interference between the heating component 30 and the pump shaft inserted into the positioning cavity 11, while ensuring that the heating area is concentrated on the hub.

[0047] like Figure 1 and Figure 2 As shown, the heating device also includes a heating assembly 30, which provides a heat source for heating the wheel hub. Specifically, the heating assembly 30 includes a burner head 31, which is mounted on the mounting portion 21. The nozzle 311 of the burner head 31 protrudes from the mounting portion 21 and faces the surface of the opening of the positioning cavity 11, i.e., the nozzle 311 faces the wheel hub. The flame and high-temperature gas generated by combustion directly act on the surface of the wheel hub, achieving efficient heating of the wheel hub. The wheel hub heats up rapidly, thereby expanding and increasing its inner diameter. The heating assembly 30 also includes an ignition element and a gas supply line 33. The ignition element is used to ignite the combustible gas, and the gas supply line 33 is connected to a gas supply device and supplies combustible gas to the burner head 31.

[0048] In this embodiment, the combustible gas can be propane. Propane has relatively stable chemical properties, produces a stable flame during combustion, and provides relatively uniform heat. It is heavier than air, does not diffuse rapidly, and can be concentrated well near the wheel hub during heating, improving heating efficiency. Furthermore, propane is typically stored and transported in liquid form, making it convenient to use. Of course, in other embodiments, provided that combustion safety is satisfied, the combustible gas can also be methane, acetylene, or hydrogen, etc.

[0049] The heating device provided in this application embodiment can be used to directionally heat the impeller hub. By heating the impeller hub, it expands, thereby reducing the tightness of its fit with the pump shaft during the taper interference fit, and enabling smooth disassembly of the impeller. Specifically, the heating device includes a base 10, a mounting base 20, and a heating component 30. The base 10 is provided with a positioning cavity 11, which can be adapted to and inserted into the pump shaft. That is, the pump shaft can be inserted into the positioning cavity 11, thereby realizing the positioning connection of the heating device. This allows it to maintain a relatively accurate and stable positional relationship with the hub at a preset position, providing a basis for the heating component 30 to position and heat the hub. The heating component 30 is installed outside the positioning cavity 11 and fixed to the base 10 through the mounting base 20. The heating component 30 includes a burner head 31. When the base 10 is connected to the pump shaft, the nozzle 311 of the burner head 31 faces the hub. At this time, the combustible gas entering the burner head 31 is ignited to form a heating flame. The flame is ejected from the nozzle 311 towards the hub, which can quickly and centrally heat the hub. Thus, when disassembling the impeller, the heating device of this embodiment first heats the hub in a specific direction. Utilizing the principle of thermal expansion and contraction, the hub expands due to heat, increasing its inner diameter and reducing the interference fit between it and the pump shaft, thereby reducing the clamping force and allowing the impeller to be disassembled from the pump shaft. This improves the impeller disassembly efficiency. Furthermore, since the burner head 31 has no physical contact with the hub, the disassembly operation will not damage the impeller and pump shaft, making the disassembly operation safer and more reliable. It also provides better support and protection for subsequent hydraulic component refurbishment.

[0050] In some embodiments, such as Figures 1 to 3 As shown, the heating assembly 30 includes a plurality of combustion heads 31, which are evenly spaced on the mounting part 21 and arranged around the positioning cavity 11.

[0051] Understandably, in related technologies, the impeller hub of the nuclear main pump is a ring structure. Its tapered interference fit with the pump shaft may result in uneven circumferential clamping force after deformation. Thus, if only a single burner head 31 is used to heat the hub at a single point, the heat transfer path is long and easily affected by the difference in metal thermal conductivity, leading to local overheating or insufficient expansion of the hub.

[0052] Based on this, multiple burners 31 are evenly spaced on the mounting part 21. The hub is fitted around the pump shaft. After the base 10 is connected to the pump shaft through the positioning cavity 11, the burners 31 are arranged around the positioning cavity 11. The nozzles 311 of all burners 31 point to the hub, forming an annular heating zone coaxial with the hub. This layout achieves geometric coaxiality between the heat source and the heated hub, which helps to achieve uniform heating of the hub.

[0053] Based on this, multiple burners 31 are distributed at equal intervals around the pump shaft, with one burner 31 set at certain angles, so that the flame or high-temperature airflow acts on the outer circumference of the hub at the same interval, ensuring that heat is transferred synchronously in the circumference of the hub and avoiding excessive local temperature difference.

[0054] In a specific embodiment, the mounting part 21 is arranged around the positioning cavity 11. The radius of the mounting part 21 needs to match the outer radius of the hub, that is, the size of the mounting part 21 can be designed according to the size of the hub. For example, if the outer diameter of the hub is 1.2 meters, the inner diameter of the mounting part 21 needs to be designed to be 1.3 meters to ensure that the distance between the burner head 31 nozzle 311 and the surface of the hub is maintained at 100mm to 150mm. This distance can ensure that the flame can fully contact the surface of the hub, and can also avoid damage caused by the high-temperature flame directly impacting the impeller blades or pump shaft.

[0055] In a specific embodiment, the heating assembly 30 includes seven combustion heads 31. When the base 10 is sleeved on the pump shaft, the seven combustion heads 31 can be used to correspond one-to-one with the positions of the seven blades of the hub.

[0056] In related technologies, the impeller of a nuclear main pump typically consists of a hub and seven blades evenly distributed around the circumference of the hub. The connection between the blades and the hub is a critical stress-bearing part of the impeller. During long-term operation, the impeller transmits power through the blades. The connection area between the blades and the hub (such as the root, welded or bolted connection points) will experience irregular deformation of the impeller keyway and hub due to stress concentration, temperature changes and other factors.

[0057] In this way, the connection positions of the seven burners 31 and the seven blades are set one by one, so that the burners 31 and the key deformation areas of the impeller hub are precisely matched in space. This ensures that the flame of the burners 31 can directly act on the connection between the blades and the hub, thereby achieving precise and efficient heating of the main deformation areas of the hub. This solves the problem of not being able to disassemble due to deformation at room temperature, and avoids energy waste or component damage caused by blind heating.

[0058] In other embodiments, such as Figures 1 to 3 As shown, the combustion head 31 may include a main body 312 and a flame head 313. The flame nozzle 311 is disposed on the flame head 313, and the flame head 313 is movably connected to the main body 312. The flame head 313 is movable relative to the main body 312.

[0059] In this embodiment, the position of the flame nozzle 311 is adjustable, that is, the position of the flame nozzle 311 of the burner head 31 in space can be changed by mechanical structure (such as sliding, rotating, telescopic etc.) to adapt to different heating requirements.

[0060] For example, the nozzle 311 can be adjusted radially, meaning the nozzle 313 can move in a direction perpendicular to the pump shaft (the axis of the positioning cavity 11), moving closer to or further away from the hub surface to accommodate hubs of different diameters (the hub sizes of different models of nuclear main pumps may differ), or to adjust the distance between the flame and the hub according to the thickness changes after hub deformation, ensuring effective flame energy transfer and avoiding burn-out from being too close or insufficient heating from being too far. Alternatively, the nozzle 311 can be adjusted axially, meaning the nozzle 313 can rotate around the circumference of the positioning cavity 11 (pump shaft), changing the angular position of the nozzle 311 on the circumference. Since irregular deformation of the hub may be concentrated in the connection area between specific blades and the hub (rather than being evenly distributed), circumferential adjustment allows the nozzle 311 to be precisely aligned with the most severely deformed area and the part with the greatest disassembly resistance. Alternatively, the nozzle 311 can be angled relative to the main body 312, that is, the nozzle 313 can be angled based on the axis of the main body 312, so that the spray direction of the nozzle 311 can be finely adjusted, avoiding the nozzle 311 being blocked by the blades (some impeller blades may tilt towards the inside of the hub), and ensuring that the flame can directly act on the surface of the hub.

[0061] In specific embodiments, the adjustable position of the flame nozzle 311 can typically be achieved through mechanical structures, hydraulic devices, or electric drives.

[0062] For example, the flame head 313 and the main body 312 are connected via a slide rail and a slider structure. A slide rail can be installed on the main body 312, and the flame head 313 is connected to the slide rail via a slider. The position of the flame nozzle 311 can be adjusted by manually or electrically moving the slider along the slide rail, such as moving it radially closer to or further away from the hub surface, or rotating it circumferentially around the pump shaft. Alternatively, a lifting drive device can be used to connect the flame head 313 and the main body 312, raising or lowering the flame head 313 to adjust the height of the flame nozzle 311. Alternatively, a hydraulic telescopic cylinder, a threaded connection structure, or casters can be used to connect the flame head 313 and the main body 312, thereby achieving position adjustment of the flame head 313, i.e., the flame nozzle 311.

[0063] In some embodiments, such as Figure 1 , Figure 2 and Figure 4 As shown, the base 10 has a first end and a second end that are arranged opposite to each other along a first direction. The opening of the positioning cavity 11 is located at the first end, the mounting base 20 is mounted at the second end, and the flame nozzle 311 is arranged facing the first end.

[0064] In this embodiment, the base 10 is a long, cylindrical structure with a first end and a second end arranged opposite each other along the axial direction of the pump shaft. The first end is the opening end of the positioning cavity 11, which faces the impeller (hub) so that the end of the pump shaft away from the impeller can be sleeved and fixed to the cavity. The second end of the base 10 is the mounting position of the mounting seat 20, which carries the burner head 31. The nozzle 311 of the burner head 31 points along the first direction toward the opening end of the positioning cavity 11, i.e., toward the impeller hub. Thus, when the base 10 is fitted onto the end of the pump shaft away from the hub, the burner head 31 mounted at the second end faces the hub, so that the nozzle 311 can act precisely on the hub surface, preventing the flame direction from deviating.

[0065] In some embodiments, such as Figure 1 , Figure 2 and Figure 4 As shown, the first end is also provided with a positioning part 12, and the opening of the positioning cavity 11 is located in the positioning part 12. When the pump shaft is inserted into the positioning cavity 11, the positioning part 12 is used to adapt and abut against the hub of the impeller sleeved on the pump shaft. The flame nozzle 311 is located between the positioning part 12 and the mounting part 21.

[0066] In this embodiment, the first end of the base 10 is provided with a positioning part 12, and the opening of the positioning cavity 11 is provided on the positioning part 12. The base 10 contacts the pump shaft and the impeller hub at the positioning part 12. The positioning part 12 is a key component for the installation and positioning of the base 10. When the pump shaft is inserted into the positioning cavity 11, the positioning part 12 is adapted to abut against the impeller hub sleeved on the pump shaft. Here, "adapted" means that the shape and size of the positioning part 12 are adapted to the corresponding part of the hub (such as the end face, stepped surface or outer peripheral contour of the hub). For example, if the end face of the hub is flat, the corresponding position of the positioning part 12 is also flat. Or, if the hub has an annular boss, the positioning part 12 is provided with a matching annular groove to ensure that the two fit tightly without gaps. Abutment emphasizes axial contact and limitation. That is, the positioning part 12 restricts the movement of the base 10 along the pump shaft axial direction (i.e., the first direction) through physical contact with the hub, and fixes the base 10 at the end of the pump shaft away from the hub.

[0067] Based on this, the mounting part 21, which serves as a component supporting the burner head 31, is located at the second end of the base 10, the positioning part 12 is located at the first end, and the nozzle 311 is located between the positioning part 12 and the mounting part 21. Along the axial direction of the pump shaft (i.e., the first direction), the nozzle 311 is located in the middle region between the positioning part 12 and the mounting part 21. That is, the main body of the burner head 31 may be mounted on the mounting part 21 at the second end, but the nozzle 311 extends between the positioning part 12 and the mounting part 21, forming a structure where the rear end of the burner head 31 is fixed and the nozzle 311 protrudes forward. In this way, the nozzle 311 being located in the middle region can balance the heating intensity and distance, ensuring that the flame energy acts efficiently on the hub. Furthermore, the positioning part 12 abuts against the hub, and the hub is located exactly at the positioning part 12 (or adjacent to the outside of the positioning part 12). Therefore, when the nozzle 311 is located in the middle region, its flame facing the first end can be directly sprayed onto the surface of the hub, and the nozzle 311 will not be blocked by the positioning part 12.

[0068] In a specific embodiment, such as Figure 1 , Figure 2 and Figure 4 As shown, the mounting part 21 is provided with a plug hole 211 for the burner head 31 to be inserted into. The plug hole 211 extends through the mounting part 21 in the first direction, and the flame nozzle 311 extends out from the plug hole 211 in the first direction.

[0069] The mounting part 21 is provided with a plug hole 211. The plug hole 211 passes through the mounting part 21 along the first direction, that is, the axis of the pump shaft. The burner head 31 is inserted into the plug hole 211. The axis of the burner head 31 is parallel to the axis of the pump shaft, so that the flame nozzle 311 sprays flames downward in a roughly axial direction toward the hub. The flame can directly act on the end face or outer peripheral surface of the hub.

[0070] In some embodiments, such as Figure 1 , Figure 3 and Figure 4 As shown, the burner head 31 has an air inlet 314 for supplying gas. The gas supply line 33 includes a main pipe 331 and at least one distribution pipe 332. The main pipe 331 is mounted on the mounting base 20 and has at least one air outlet. The inlet and outlet of the distribution pipe 332 are connected to each other, and the outlet of the distribution pipe 332 is connected to the air inlet 314.

[0071] In this embodiment, the gas supply pipeline 33 includes a main pipe 331 and a distribution pipe 332. The main pipe 331 is installed on the mounting base 20 and is the main channel for gas supply. One end of the main pipe 331 is connected to an external gas supply device (such as a gas cylinder, gas pipeline, etc.), and the other end is closed. At least one gas outlet is opened on the side wall. The number of gas outlets corresponds to the number of burners 31. For example, seven gas outlets correspond to seven burners 31. The gas outlets are connected to the burners 31 through the distribution pipe 332, which collects gas from a single gas source and distributes it to each burner 31.

[0072] Thus, by designing the diameter, length, and connection position of the main pipe 331 and the distribution pipe 332, the gas pressure and flow of each burner head 31 can be balanced, ensuring consistent flame intensity. In addition, by inheriting the gas supply pipeline 33 and installing it in the mounting part 21, the overall structure of the heating device is more compact and easier to maintain.

[0073] In a specific embodiment, an igniter (not shown) is located at the gas outlet and is used to ignite the combustible gas ejected from the gas outlet. An igniter is installed at each gas outlet to ignite the combustible gas entering each burner head 31.

[0074] Of course, in other embodiments, as shown in the figure, the igniter may also be disposed within each burner head 31.

[0075] In some embodiments, such as Figure 1 , Figure 2 and Figure 4 As shown, the mounting base 20 includes a first mounting plate 22 and a second mounting plate 23 spaced apart. The mounting part 21 is located on the first mounting plate 22, and the second mounting plate 23 is located on the side of the first mounting plate 22 away from the opening of the positioning cavity 11. The air supply line 33 is installed on the second mounting plate 23.

[0076] In this embodiment, the mounting base 20 includes a first mounting plate 22 and a second mounting plate 23. The first mounting plate 22 and the second mounting plate 23 are spaced apart, for example, they are spaced apart along a first direction. This spaced arrangement can leave space in the middle area for the installation and routing of components such as distribution pipes 332, and also facilitates the installation and disassembly of components, improving the stability and maintainability of the structure.

[0077] The mounting part 21 is disposed on the first mounting plate 22. The mounting part 21 is used to mount the burner head 31. The placement of it on the first mounting plate 22 facilitates its cooperation with other structures such as the positioning cavity 11, allowing the burner head 31 to be positioned relatively close to the entrance of the positioning cavity 11, i.e., close to the hub, so that the flame nozzle 311 can heat the hub. The second mounting plate 23 is located on the side of the first mounting plate 22 away from the opening of the positioning cavity 11. The gas supply pipe 33 is installed on the second mounting plate 23. Since the gas supply pipe 33 needs to be connected to the burner head 31 and other components, its installation on the second mounting plate 23 makes the connection between the gas supply pipe 33 and the burner head 31 smoother. It also facilitates the fixing and maintenance of the gas supply pipe 33, ensuring that the combustible gas can be smoothly delivered to the burner head 31, thus ensuring the normal operation of the device.

[0078] In some embodiments, such as Figure 3 and Figure 4 As shown, the heating device also includes a flow control valve 50, which is installed on the main pipe 331 or the distribution pipe 312 and is used to control the flow rate of the combustible gas.

[0079] In a specific embodiment, the heating device has different heat requirements under different operating conditions. By setting a flow control valve 50, the flow rate of combustible gas can be flexibly adjusted according to the actual operating conditions to meet different heating needs. For example, in the initial stage of heating, the flow rate can be increased to allow the heating device to quickly reach the set temperature; when the temperature approaches the set value, the flow rate can be reduced to maintain a stable temperature.

[0080] For example, in a specific embodiment, the flow rate of the combustible gas is controlled by the flow control valve 50. Within 10 to 15 minutes of ignition, the impeller hub is heated to a predetermined temperature. Thereafter, the flow rate of the combustible gas is reduced while the hub is continuously heated until its expansion meets the requirements for impeller disassembly. To avoid significant damage to the blades and pump shaft, the temperature of the hub is controlled to not exceed 400°C during heating.

[0081] In a specific embodiment, the flow control valve 50 can be a pneumatic diaphragm regulating valve, a solenoid valve, a thermal mass flow controller, or an electric ball valve, etc.

[0082] In some embodiments, such as Figure 1 and Figure 2 As shown, the heating device also includes a gas leakage detection module 40, which is installed on the second mounting plate 23 and is used to detect whether there is free combustible gas in the environment.

[0083] In this embodiment, the gas leak detection module 40 is mainly used to detect the presence of free combustible gas in the environment. It typically includes a combustible gas sensor, which converts the detected combustible gas concentration into an electrical signal. For example, when the detected gas concentration exceeds a safety threshold, the module triggers an alarm device, such as issuing an audible and visual alarm, to promptly alert the user to a dangerous situation. Thus, by monitoring combustible gas in the environment, gas leaks can be detected in a timely manner, preventing explosions, fires, and other safety accidents caused by the accumulation of leaked gas, thereby ensuring the safety of equipment and personnel.

[0084] In a specific embodiment, the gas leakage detection module 40 can be a semiconductor gas sensor, a contact combustion gas sensor, an electrochemical gas sensor, or an optical sensor, etc.

[0085] In some embodiments, the heating device further includes a temperature sensor (not shown) mounted on the second mounting plate 23 and used to detect the temperature of the wheel hub.

[0086] Temperature sensors are used to monitor the actual temperature of the wheel hub in real time, providing data for the intelligent adjustment of the heating device. For example, when the wheel hub temperature has not reached the threshold required for disassembly, the control system can increase the flow rate of combustible gas through the flow control valve to enhance the flame intensity; when the temperature approaches the target value, the flow rate is reduced to avoid overheating, preventing the wheel hub material from undergoing performance changes due to high temperatures, or preventing excessively high temperatures from damaging components such as the pump shaft and blades.

[0087] In a specific embodiment, considering that the heating temperature of the wheel hub may reach 100℃-300℃ and there is flammable gas in the environment, the temperature sensor can be an explosion-proof thermocouple, such as a K-type explosion-proof thermocouple or an infrared temperature sensor.

[0088] In some embodiments, the flow control valve, combustible gas detection module, and temperature sensor described above can work together, for example, by exchanging information through a single control panel. Thus, the heating device of this embodiment can be designed as an automated control device. Furthermore, various preset information, such as heating temperature, flame size adjustment, alarm temperature, hub temperature, heating time, pump shaft temperature, and heating flame control, can be input into the control panel. The control panel works in conjunction with the flow control valve, combustible gas detection module, and temperature sensor to improve the automation and intelligence of the heating process.

[0089] For example, when the combustible gas detection module detects a gas leak, the flow control valve controls the shut-off of the gas supply line 33, the burner head 31 automatically stops heating, and the combustible gas detection device can provide feedback on the gas leak information, so that the operator can handle the gas leak fault in a timely manner based on the gas leak signal.

[0090] In some embodiments, such as Figures 1 to 4As shown, the mounting section 21 can also be equipped with a lifting ring 24, which can be used in conjunction with an external lifting device to move the heating device.

[0091] In some other embodiments, a push rod (not shown) may be provided at the end of the base 10 away from the entrance of the positioning cavity 11. The push rod extends along the first direction and can serve as an auxiliary rod to facilitate the movement and disassembly of the heating device when it is being disassembled or assembled.

[0092] In other embodiments, the heating device can also be shielded at various locations according to the radiation dose of the nuclear main pump, such as by covering it with a nuclear radiation shielding film or by using nuclear radiation shielding materials to make the heating device, so as to reduce the adverse effects of nuclear radiation on the heating device and extend the service life of the heating device.

[0093] Another embodiment of this application provides a nuclear main pump impeller disassembly device, which includes an isolation cover and a heating device provided in any of the above embodiments. The isolation cover (not shown) is used to surround and shield the impeller from the periphery of the impeller, and the nozzle 311 extends into the isolation cover.

[0094] In this embodiment, the nuclear main pump impeller disassembly device includes a heating device nuclear isolation shroud. The isolation shroud forms a semi-enclosed or closed protective structure around the impeller, surrounding and shielding it. With the flame nozzle 311 extending into the shroud, the isolation shroud encloses the flame and impeller hub within a limited space, reducing heat loss to the outside and allowing more heat to act on the hub surface. For example, the isolation shroud can be made of high-temperature resistant insulation material (such as aluminum silicate fiber), with an inner wall reflectivity >80%, allowing heat to be more concentrated and further enhancing heat utilization. Simultaneously, the isolation shroud surrounds and isolates the impeller, preventing flame overflow and blocking the flame of the burner head 31 from directly contacting surrounding equipment, avoiding fires or equipment damage caused by flame overflow. Furthermore, the isolation shroud can block high-temperature radiation, providing a safe operating distance for on-site operators.

[0095] In a specific embodiment, the size of the isolation cover needs to match the impeller so that the flame nozzle 311 is inserted and maintains a certain distance from the surface of the hub, which avoids local overheating caused by excessive distance and ensures efficient transfer of flame energy.

[0096] The description of the various embodiments above tends to emphasize the differences between the various embodiments. The similarities or similarities between them can be referred to, and for the sake of brevity, they will not be repeated here.

[0097] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A heating device for heating the hub of an impeller during disassembly of a nuclear main pump, characterized in that, include: The base has a positioning cavity with at least one open end. The base has a first end and a second end that are arranged opposite to each other along a first direction. The first end is also provided with a positioning part. The opening of the positioning cavity is located in the positioning part. The positioning cavity is used for the pump shaft of the nuclear main pump to be adapted and inserted. When the pump shaft is inserted into the positioning cavity, the positioning part is adapted and abuts against the hub of the impeller sleeved on the pump shaft. A mounting base is installed at the second end of the base. The mounting base includes a first mounting plate and a second mounting plate spaced apart. The first mounting plate has a mounting portion located outside the positioning cavity, and the second mounting plate is located on the side of the first mounting plate opposite to the opening of the positioning cavity. A heating assembly is disposed on the mounting base. The heating assembly includes at least one burner head mounted on the mounting base. The burner head has an air inlet for supplying combustible gas. The heating assembly also includes an ignition element and a gas supply pipeline. The gas supply pipeline is mounted on the second mounting plate and includes a main pipe and at least one distribution pipe. The main pipe has at least one air outlet. The inlet of the distribution pipe is connected to the air outlet in a one-to-one correspondence. The outlet of the distribution pipe is connected to the air inlet. The gas supply pipeline is used to connect the burner head and a gas supply device that provides combustible gas. The ignition element is used to ignite the combustible gas entering the burner head to burn. The burner head has a nozzle that protrudes from the surface of the mounting part facing the opening of the positioning cavity and is located between the positioning part and the mounting part. The nozzle is positioned facing the first end of the base. The mounting part has a plug-in hole for the burner head to be fitted and inserted. The plug-in hole extends through the mounting part along the first direction. The nozzle extends out of the plug-in hole along the first direction. The nozzle is used to spray out the combustible gas.

2. The heating device as described in claim 1, characterized in that, The heating assembly includes a plurality of combustion heads, which are evenly spaced on the mounting portion and arranged around the positioning cavity.

3. The heating device as described in claim 2, characterized in that, The heating assembly includes seven combustion heads, which, when the base is fitted onto the pump shaft, correspond one-to-one with the positions of the seven blades connecting to the hub.

4. The heating device as described in claim 1, characterized in that, The combustion head includes a main body and a flame head, the flame nozzle is disposed on the flame head, the flame head is movably connected to the main body, and the flame head is movable relative to the main body.

5. The heating device according to any one of claims 1 to 4, characterized in that, The heating device also includes a flow control valve, which is installed on the main pipe or distribution pipe and is used to control the flow rate of combustible gas. And / or, the heating device further includes a leak detection module, which is installed on the second mounting plate and used to detect whether there is free combustible gas in the environment; And / or, the heating device further includes a temperature sensor mounted on the second mounting plate and used to detect the temperature of the pump shaft.

6. A nuclear main pump impeller disassembly device, characterized in that, The device includes an isolation shroud and a heating device as described in any one of claims 1 to 5, wherein the isolation shroud surrounds and shields the impeller from its periphery, and the flame nozzle extends into the isolation shroud.

Images