Shield pump of nuclear reactor

Abstract

The utility model discloses a nuclear reactor shield pump, which comprises a shell structure, the shell structure comprises a pump shell, a pump cover assembly and a fastening assembly, one end of the pump shell is open, the pump cover assembly is matched on the open end of the pump shell, and the pump cover assembly is connected to the open end of the pump shell through the fastening assembly; a first cavity used for containing the motor unit and a second cavity used for containing the impeller unit are formed in the pump shell, and a pump inlet and a pump outlet which are communicated with the impeller unit are formed in the pump shell. According to the shield pump, the shell structure serves as a shell of the shield pump, the motor unit, the impeller unit and the like are contained in the shell structure, the structure is compact, the space size occupied by the shield pump is reduced, and safety is improved; the shell structure is convenient to disassemble and assemble, so that internal components can be conveniently pulled out for replacement and maintenance, and maintenance procedures are reduced.

Description

Technical Field

[0001] This utility model relates to the field of shielded pump technology, and in particular to a shielded pump for a nuclear reactor. Background Technology

[0002] Currently, in the structure of the shielded centrifugal pumps commonly used in nuclear power plants, the shielded pump casing and the shielded pump motor are separate units, and the flange connection is often located on top of the pump body. This structural method will result in a larger overall size of the pump, especially in some small spaces, where the conventional structure of the shielded centrifugal pump cannot meet the space layout requirements. Utility Model Content

[0003] The technical problem to be solved by this invention is to provide an improved shielded pump for nuclear reactors.

[0004] The technical solution adopted by this utility model to solve its technical problem is: to provide a shielded pump for a nuclear reactor, including a shell structure, the shell structure including a pump shell with one end open, a pump cover assembly and a fastening assembly, the pump cover assembly being fitted on the open end of the pump shell, and the fastening assembly being connected to the open end of the pump shell.

[0005] The pump casing includes a first chamber for accommodating the motor unit and a second chamber for accommodating the impeller unit, and the pump casing is provided with a pump inlet and a pump outlet respectively connected to the impeller unit.

[0006] In one embodiment, the pump inlet and the pump outlet are respectively located on the closed end of the pump casing, and respectively correspond to the inlet side and outlet side of the impeller unit.

[0007] In one embodiment, the open end of the pump casing is provided with a positioning part, and the positioning part is provided with a first step surface and a second step surface, the second step surface being located around the first step surface;

[0008] The pump cover assembly abuts against the first step surface, and the fastening assembly cooperates and fastens to the second step surface and interferes with the pump cover assembly, thereby restricting the pump cover assembly from disengaging from the first step surface.

[0009] In one embodiment, the fastening assembly includes a connecting flange and a plurality of fastening bolts;

[0010] The connecting flange abuts against the second step surface, and the inner peripheral portion of the connecting flange protrudes from the first step surface, abutting against the outer periphery of the end of the pump cover assembly;

[0011] A plurality of the fastening bolts are distributed circumferentially along the connecting flange, passing through and locking the connecting flange and the second step surface; and / or, a trapezoidal gasket is used to seal the outer periphery of the end of the pump cover assembly with the first step surface.

[0012] In one embodiment, on the positioning portion, the second step surface is higher than the first step surface.

[0013] In one embodiment, the pump cover assembly includes an upper cover and a top cover;

[0014] The upper cover fits onto the open end of the pump housing, and the upper cover has a central channel inside, which connects to the first chamber; the top of the upper cover has an opening that connects to the central channel; the top cover fits onto the opening, and the space between the top cover and the inner side of the opening forms an air collecting chamber.

[0015] In one embodiment, the top cover is provided with a through hole communicating with the gas collection chamber.

[0016] In one embodiment, the inner surface of the top cover facing the opening is an arcuate surface that arches away from the opening.

[0017] In one embodiment, the periphery of the top cover is provided with a through fluid channel.

[0018] This utility model also provides a shielded pump, including the housing structure described in any of the above, and further including a motor unit and an impeller unit assembled in the housing structure, wherein the impeller unit is connected to the shaft end of the motor unit.

[0019] The beneficial effects of this utility model are as follows: the shell structure serves as the outer casing of the canned pump, housing the motor unit and impeller unit, resulting in a compact structure that reduces the space occupied by the canned pump and improves safety; the shell structure facilitates disassembly and assembly, making it easy to remove internal components for replacement and maintenance, thus reducing maintenance procedures. Attached Figure Description

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0021] Figure 1 This is a longitudinal cross-sectional structural diagram of a shielded pump for a nuclear reactor according to an embodiment of the present invention. Detailed Implementation

[0022] To provide a clearer understanding of the technical features, objectives, and effects of this utility model, the specific embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0023] like Figure 1As shown, a shielded pump for a nuclear reactor according to an embodiment of the present invention includes a shell structure 10 and a motor unit 20 and an impeller unit 30 assembled within the shell structure 10; the motor unit 20 is connected to the impeller unit 30 and drives the impeller unit 30 to rotate.

[0024] The housing structure 10 is provided with a pump inlet 101 and a pump outlet 102 that communicate with the impeller unit 30. The pump inlet 101 corresponds to the inlet side of the impeller unit 30, and the pump outlet 102 corresponds to the outlet side of the impeller unit 30. When the impeller unit 30 rotates under the drive of the motor unit 20, fluid can enter from the pump inlet 101, pass through the outlet side of the impeller unit 30, and be output from the pump outlet 102.

[0025] The housing structure 10 includes a pump housing 11 with one open end, a pump cover assembly, and a fastening assembly 14. The pump cover assembly is fitted onto the open end of the pump housing 11 and is connected to the open end of the pump housing 11 by the fastening assembly 14, thereby closing the open end of the pump housing 11.

[0026] The pump casing 11 includes a first chamber 110 for accommodating the motor unit 20 and a second chamber 120 for accommodating the impeller unit 30. The second chamber 120 is located inside the closed end of the pump casing 11, and the first chamber 110 connects the second chamber 120 and the open end of the pump casing 11.

[0027] The motor unit 20 is housed in the first chamber 110, and the impeller unit 30 is housed in the second chamber 120. The pump inlet 101 and the pump outlet 102 are respectively opened on the closed end of the pump casing 11 corresponding to the second chamber 120, so that the pump inlet 101 and the pump outlet 102 are respectively connected to the inlet side and the outlet side of the impeller unit 30.

[0028] In such Figure 1 In the illustrated embodiment, the pump inlet 101 may be formed on the closed end face of the pump housing 11, located at opposite ends of the pump housing 11 to the pump cover assembly. The pump outlet 102 is formed on the side wall of the pump housing 11.

[0029] To connect the pump cover assembly, the open end of the pump housing 11 is provided with a positioning part 103, which may be a protrusion structure provided on the open end. The positioning part 103 is provided with a first stepped surface 104 and a second stepped surface 105, with the second stepped surface 105 located around the first stepped surface 104. The pump cover assembly abuts against the first stepped surface 104, and the fastening assembly 14 engages and is fastened to the second stepped surface 105, interfering with the pump cover assembly and preventing the pump cover assembly from disengaging from the first stepped surface 104.

[0030] Preferably, on the positioning part 103, the second step surface 105 is higher than the first step surface 104, so that the second step surface 105 protrudes from the outer periphery of the first step surface 104 and relative to the first step surface 104, forming a height difference between the two.

[0031] Alternatively, the fastening assembly 14 may include a connecting flange 141 and a plurality of fastening bolts 142; the connecting flange 141 abuts against the second stepped surface 105, and the plurality of fastening bolts 142 are distributed circumferentially along the connecting flange 141, passing through and locking onto the connecting flange 141 and the second stepped surface 105.

[0032] The inner peripheral portion 143 of the connecting flange 141 protrudes from the first stepped surface 104 and abuts against the outer periphery of the pump cover assembly, thereby interfering with the pump cover assembly and preventing it from disengaging from the first stepped surface 104. A sealing gasket (not shown) is also provided between the inner peripheral portion 143 of the connecting flange 141 and the outer periphery of the pump cover assembly to seal the gap between them. Depending on the mating surface form of the inner peripheral portion 143 of the connecting flange 141 and the outer periphery of the pump cover assembly, a trapezoidal gasket is preferred.

[0033] To facilitate the contact of the inner peripheral portion 143 of the connecting flange 141, a positioning bevel 121 may be provided on the outer periphery of the end of the pump cover assembly.

[0034] Specifically, the pump cover assembly can be an integral cover structure or a separate structure.

[0035] like Figure 1 As shown, in one embodiment, the pump cover assembly includes an upper cover 12 and a top cover 13. The upper cover 12 fits onto the open end of the pump housing 11, and the top cover 13 fits onto the upper cover 12. The upper cover 12 abuts against a first stepped surface 104 at its end facing the pump housing 11, and a positioning ramp 121 is provided on the outer periphery of the end of the upper cover 12.

[0036] Furthermore, the upper cover 12 has a central channel inside, which connects to the first chamber 110; the top of the upper cover 12 has an opening that connects to the central channel. The top cover 13 fits onto the opening, and the space between the top cover 13 and the inner side of the opening forms a gas collecting chamber 130. When the shielded pump draws in fluid, the gas inside the fluid can be concentrated into the gas collecting chamber 130 along the gaps inside the pump casing 11.

[0037] The top cover 13 is provided with a through hole 132 that connects to the gas collection chamber 130. The through hole 132 can be used as an inspection hole or as an exhaust hole. The top cover 13 and the upper cover 12 are also sealed by a sealing gasket, preferably a copper flat gasket.

[0038] Preferably, the inner surface of the top cover 13 facing the opening is an arc-shaped surface 131 that arches away from the opening, and the arc-shaped surface 131 increases the volume of the air collection chamber 130.

[0039] In one embodiment, the periphery of the upper cover 12 is also provided with a through fluid channel 122, which may include an inlet channel and an outlet channel for connecting to a heat exchange tube, for introducing and discharging fluid, and for realizing heat exchange between fluids.

[0040] The motor unit 20 is housed within the first chamber 110 of the pump casing 11. The motor unit 20 includes a stator 21, a rotor 22, and other structures. This motor unit 20 can be implemented using existing technology and will not be described in detail here.

[0041] The base of the motor unit 20 is connected to the upper cover 12 of the pump cover assembly, isolating the stator 21, rotor 22, and other structures inside the base from the pump casing 11. The first end of the pump shaft, which passes through the center of the rotor 22, is connected to the impeller unit 30, while the opposite second end extends into the central channel of the upper cover 12. The second end of the pump shaft engages with the central channel via a thrust bearing assembly, enabling the pump shaft to be positioned and rotate relative to the upper cover 12. The axial force of the entire rotor 22 is borne by the thrust bearing assembly.

[0042] The impeller unit 30 is located within the second chamber 12 of the pump casing 11 and is connected to the first end of the pump shaft. Specifically, the impeller unit 30 may include an impeller 31 connected to the first end of the pump shaft and a guide vane 32. The guide vane 32 is sleeved on the outside of the impeller 31 and connected to the stator 21 of the motor unit 20, serving to guide the fluid flow. The end 321 of the guide vane 32 facing away from the stator 21 can be fitted into the pump inlet 101, allowing the pump inlet 101 to communicate with the interior of the guide vane 32. The side wall of the guide vane 32 is provided with a water outlet 322, which communicates with the pump outlet 102.

[0043] Furthermore, the shielded pump of the nuclear reactor may also include a heat exchange tube 40. The heat exchange tube 40 adopts a coil structure and is installed between the inner wall of the motor unit 20 and the pump casing 11. The inlet and outlet ends of the heat exchange tube 40 are connected to the inlet and outlet channels of the fluid channel, respectively. Cooling fluid can enter the heat exchange tube from the inlet channel, undergo heat exchange along the heat exchange tube 40, and then be discharged from the outlet channel. Through the installation of the heat exchange tube 40 and heat exchange, the motor unit 20 can be cooled, preventing overheating problems and malfunctions during operation, thereby ensuring the normal operation of the motor unit 20.

[0044] In summary, the shielded pump for nuclear reactors of this invention adopts a shell structure 10, which houses the motor unit 20 and impeller unit 30, making the entire pump more compact and greatly reducing the pump's spatial volume, thus meeting the requirements for small space layout.

[0045] When overhauling a canned motor pump, there is no need to disassemble the entire pump. Only the pump cover assembly of the casing structure needs to be opened to remove the pump shaft, stator, and rotor for replacement and maintenance, thereby reducing maintenance procedures.

[0046] The shielded pump for nuclear reactors of this invention has a shell structure that serves as the primary loop pressure boundary, which can better contain the primary loop and improve safety.

[0047] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the description and drawings of this utility model, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A canned pump for a nuclear reactor, characterized in that, The shell structure comprises a pump shell with an open end, a pump cover assembly fitted on the open end of the pump shell, and a fastening assembly connected to the open end of the pump shell; The interior of the pump shell comprises a first chamber for accommodating a motor unit and a second chamber for accommodating an impeller unit, and the pump shell is provided with a pump inlet and a pump outlet respectively communicating with the impeller unit.

2. The canned pump of a nuclear reactor according to claim 1, characterized in that, The pump inlet and the pump outlet are respectively arranged on the closed end of the pump shell and correspond to the inlet side and the outlet side of the impeller unit respectively.

3. The canned pump of a nuclear reactor according to claim 1, characterized in that, The open end of the pump shell is provided with a positioning portion, the positioning portion is provided with a first step surface and a second step surface, and the second step surface is located at the periphery of the first step surface; The pump cover assembly abuts against the first step surface, and the fastening assembly is fitted and fastened on the second step surface and interferes with the pump cover assembly to limit the pump cover assembly from separating from the first step surface.

4. The canned pump of claim 3, wherein, The fastening assembly comprises a connecting flange and a plurality of fastening bolts; The connecting flange abuts against the second step surface, and the inner peripheral portion of the connecting flange protrudes beyond the first step surface and abuts against the end peripheral portion of the pump cover assembly; The plurality of fastening bolts are distributed along the circumference of the connecting flange, and are threaded through and locked on the connecting flange and the second step surface.

5. The canned pump of claim 3, wherein, On the positioning portion, the second step surface is higher than the first step surface; and / or, the end peripheral portion of the pump cover assembly and the first step surface are sealed by a trapezoidal gasket.

6. The canned pump of a nuclear reactor according to any one of claims 1-5, characterized in that, The pump cover assembly comprises an upper cover and a top cover; The upper cover is fitted on the open end of the pump shell, the interior of the upper cover has a central passage, the central passage communicates with the first chamber; the top of the upper cover is provided with an opening communicating with the central passage; the top cover is fitted on the opening, and the space between the inner side of the top cover and the opening forms a gas collection cavity.

7. The canned pump of a nuclear reactor according to claim 6, characterized in that, The top cover is provided with a through hole communicating with the gas collection cavity.

8. The canned pump of claim 6, wherein, The inner surface of the top cover facing the opening is an arc surface arched away from the opening.

9. The canned pump of claim 6, wherein, The peripheral edge of the upper cover is provided with a fluid passage.

10. The canned pump of any one of claims 1-5, wherein, Further comprising a motor unit and an impeller unit assembled in the shell structure, and the impeller unit is connected to the shaft end of the motor unit.

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