Compact small reactor main pump structure

Abstract

The invention discloses a compact small reactor main pump structure, and belongs to the technical field of nuclear power main pump devices. The structure comprises a pump shell assembled above the shielding motor, a containing cavity used for cooling medium circulation is formed in the inner side, located above the shielding motor, of the pump shell, the containing cavity comprises a water inlet cavity located on the top and a cooling cavity located on the lower portion and located above the shielding motor, the water inlet cavity is communicated with a water inlet pipe, and the cooling cavity is communicated with a water outlet pipe. An impeller and a guide vane are arranged in the cooling cavity; according to the compact type small reactor main pump structure, the integrated pump shell structure is adopted, the structural design that the whole containing cavity is fully divided in the internal structural design is adopted so that the whole space can be fully utilized, the space can be fully utilized, and the compact design of a main pump can be further achieved; therefore, the use requirements of the compact reactor cooling pump system are completely met.

Description

Technical Field

[0001] The present invention relates to a structure of a main pump for a compact small reactor, belonging to the technical field of nuclear power main pump devices. Background Art

[0002] The reactor coolant pump is one of the important key equipment in the nuclear power system. In the structure disclosed in the publicly available comparative document (application number: 201510203602.1), it involves structures such as a canned motor, a thermal insulation screen, a pump body, a diffuser, an impeller rear seal ring, a canned motor shaft, an impeller, an impeller front seal ring, etc. However, when applied to a small reactor, due to the need for the overall space structure, it is necessary to achieve the compactness of the main pump, but the structural design cannot meet the corresponding requirements.

[0003] Publication 2 (application number: 201710844455.5) discloses a nuclear main pump for a small nuclear power plant. According to its specific structural design, the overall circulation requirements and the application effect of the overall structural design in the application of a small reactor are not the expected effects, and in the structural design, especially based on the environment of a small reactor, there is still a large space for optimization.

[0004] The structure of the nuclear power coolant pump usually still adopts the conventional coolant circulation effect combined with an impeller. The space for optimizing the overall structure is relatively small. However, in terms of considering the compactness of the structure, both the overall cooling effect and the flow rate need to be considered. In the case of reducing the original space, in order to better achieve the cooling effect, the cooling effect can naturally be improved by increasing the flow rate. A slightly faster flow rate will result in a better overall liquid circulation effect and a lower cooling medium can be obtained.

[0005] At the same time, according to the records disclosed in the experimental study on the influence of the integrated structure on the hydraulic performance of the nuclear main pump (Pump Technology, No. 4, 2023, Liao Juan; Zhong Yun; Lu Yuheng; Zhang Xing), it also involves the precautions and disadvantages of the integrated pump casing structure. In actual applications, in combination with the design of the integrated pump casing, it is preferred for a compact structure, but the specific structural optimization is an important problem that needs to be considered for improvement. Summary of the Invention

[0006] The object of the present invention is to provide a structure of a main pump for a compact small reactor, which can effectively make full use of the internal space on the basis of an integrally formed pump casing, and effectively achieve the overall compact design and effect in combination with the design of the diffuser.

[0007] The technical solution adopted by the present invention is as follows:

[0008] A compact small reactor main pump structure includes a pump casing assembled above a canned motor. An inner side of the pump casing above the canned motor is provided with a cavity for cooling medium circulation. The cavity includes a water inlet cavity at the top and a cooling cavity at the lower part and above the canned motor. The water inlet cavity is communicated with a water inlet pipe, and the cooling cavity is communicated with a water outlet pipe. An impeller and a guide vane are arranged in the cooling cavity.

[0009] Further, the pump casing is assembled above the canned motor through bolts. A sealing structure is arranged on the assembled joint surface. The sealing structure includes a gasket and a C-shaped sealing ring.

[0010] Further, the upper and lower sides of the C-shaped sealing ring are fixed by welding.

[0011] Further, a partition plate is arranged in the water inlet cavity for shunting the coolant before the impeller inlet.

[0012] Further, a conduit is arranged above the impeller and at the joint of the water inlet cavity and the cooling cavity to form an impeller inlet for guiding the coolant to the impeller.

[0013] Further, a guide vane is arranged at the bottom of the conduit. The impeller drives the coolant to flow out from the guide vane and out through the water outlet pipe. The guide vane is fixedly assembled on the top of the canned motor.

[0014] Further, there is an assembly surface between the conduit and the guide vane, and an opening ring is arranged on this assembly surface as a seal.

[0015] Further, a front sealing ring is also arranged between the guide vane and the impeller.

[0016] Further, the impeller is assembled on the rotor of the canned motor. An insulating seat is also arranged below the impeller. An insulating body is arranged between the insulating seat and the top of the canned motor. A rear sealing ring is arranged between the impeller and the insulating seat.

[0017] Further, the water inlet pipe and the water outlet pipe are the same pipe orifice, and a partition plate is arranged in this pipe orifice to form the water inlet pipe and the water outlet pipe.

[0018] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention are as follows:

[0019] 1. The compact small reactor main pump structure of the present invention adopts an integrated pump casing structure. In the internal structure design, the structure of the entire cavity is fully divided to realize the full utilization of the entire space. The space can be fully utilized, and further, the compact design of the main pump can be realized, thus fully meeting the use requirements of the compact reactor coolant pump system;

[0020] 2. A compact small reactor main pump structure of the present invention divides the inlet and outlet into two halves with the same pipeline. The coolant flows in from one half of the pipeline and enters the large ring cavity. A partition is arranged in the ring cavity to achieve the diversion of the coolant before the impeller inlet. With the reasonable design of the pipeline structure, the application of the integral pump shell structure is effectively realized, so that this structure can be fully applied.

[0021] 3. A compact small reactor main pump structure of the present invention can effectively realize the circulation of the coolant inside the whole body and maintain the cooling effect of the whole main pump by means of the structural design of the integral guide vane, impeller and conduit. At the same time, with the design of the heat insulation pad, the integral pump shell and the canned motor form the pressure boundary of the reactor coolant system, ensuring the actual application effect of this design. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention will be described by way of examples with reference to the accompanying drawings, where:

[0023] Figure 1 is the structural schematic diagram of the present invention;

[0024] Figure 2 is the enlarged structural schematic diagram at A.

[0025] Reference numerals in the drawings: 1 - canned motor, 2 - pump shell, 3 - water inlet cavity, 4 - cooling cavity, 5 - impeller, 6 - guide vane, 7 - gasket, 8 - C-shaped seal ring, 9 - partition, 10 - conduit, 11 - split ring, 12 - front seal ring, 13 - heat insulation seat, 14 - heat insulation body, 15 - rear seal ring, 16 - water inlet pipe, 17 - water outlet pipe. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] All features disclosed in this specification, or all steps in the disclosed methods or processes, except for mutually exclusive features and / or steps, can be combined in any way.

[0027] Any feature disclosed in this specification, unless specifically described, can be replaced by other equivalent or similar-purpose alternative features. That is, unless specifically described, each feature is only an example of a series of equivalent or similar features.

[0028] Embodiment

[0029] A compact small reactor main pump structure, as shown in Figure 1 and Figure 2As shown in the figure, it includes a pump casing 2 above the assembled and shielded motor 1. The pump casing 2 is provided with a cavity for cooling medium circulation on the inner side above the shielded motor 1. The cavity includes a water inlet cavity 3 at the top and a cooling cavity 4 at the lower part and above the shielded motor 1. The water inlet cavity 3 is connected to the water inlet pipe 16, and the cooling cavity 4 is connected to the water outlet pipe 17. An impeller 5 and a guide vane 6 are arranged in the cooling cavity 4.

[0030] In this embodiment, in the specific structural design, the internal cavity of the overall pump casing 2 adopts a more optimized modular design, so that the entire internal space structure can be fully utilized. With the design advantages of this method, a compact design of the entire pump casing 2 structure can be effectively achieved. At the same time, in this design, the pump casing 2 adopts an integrated design (i.e., one-piece molding). Taking advantage of the overall connection of the integrated structure and considering the deficiencies of the overall structure in rare technologies, the entire pump casing 2 structure can be formed more in accordance with the required structure by optimizing the internal structure, effectively achieving a compact design and being applicable.

[0031] Based on the above specific structural design, the pump casing 2 is assembled above the shielded motor 1 through bolts. A sealing structure is arranged on the assembled mating surface. The sealing structure includes a gasket 7 and a C-shaped sealing ring 8. In this structural design, it is mainly to consider the sealing between the pump casing 2 and the shield clip to prevent the coolant (water) from invading the motor. With the structural design of the C-shaped sealing ring 8 based on its certain elasticity, it can fully meet the expansion amount of the unit due to heat or misalignment sealing caused by vibration, etc., and completely ensure the sealing effect of the entire structure.

[0032] As a more specific design, in order to further ensure the sealing effect, the upper and lower sides of the C-shaped sealing ring 8 are fixed by welding. In the design of this structure, both the upper and lower sides of the C-shaped sealing ring 8 are completely welded by welding process to form a sealing weld, thus ensuring the sealing effect and being able to completely achieve the effect of no liquid leakage.

[0033] Based on the above specific structural design, a partition 9 is arranged in the water inlet cavity 3 to be used for the diversion of the coolant before the inlet of the impeller 5. As a specific design, the diversion of the coolant before the inlet of the impeller 5 is realized.

[0034] Based on the above specific structural design, further, a conduit 10 is arranged above the impeller 5 and at the junction of the water inlet cavity 3 and the cooling cavity 4 to form an inlet of the impeller 5 for guiding the coolant to the impeller 5. In this structure, the conduit 10 is fixedly assembled on the pump casing 2 through bolts and is located inside. The water entering is directly diverted to the impeller 5 through the conduit 10, further ensuring the liquid circulation inside the entire pump casing 2.

[0035] Based on the design of the above specific structure, more specifically, a guide vane 6 is provided at the bottom of the bottom of the conduit 10. The impeller 5 drives the coolant to flow out from the guide vane 6 and out through the water outlet pipe 17. The guide vane 6 is fixedly assembled on the top of the canned motor 1. The design of the guide vane 6 structure can achieve the flow rate and effect of the entire internal liquid circulation. Moreover, the structure of the guide vane 6 has a large inlet and a small outlet, thereby realizing the flow rate of the entire liquid. On the one hand, it can achieve the rapid replacement of the medium, and thus further ensure the cooling effect of the entire structure under the compact structure design basis.

[0036] Based on the design of the above specific structure, more specifically, there is an assembly surface between the conduit 10 and the guide vane 6, and an opening ring 11 is provided on this assembly surface as a seal. Further, a front seal ring 12 is also provided between the guide vane 6 and the impeller 5.

[0037] As a more optimized design, the impeller 5 is assembled on the rotor of the canned motor 1. An insulating seat 13 is also provided below the impeller 5. An insulating body 14 is also provided between the insulating seat 13 and the top of the canned motor 1. A rear seal ring 15 is provided between the impeller 5 and the insulating seat 13. In this design, an installation cavity is provided at the bottom of the insulating seat 13, and the insulating body is provided in the installation cavity to prevent the canned motor 1 from overheating.

[0038] Based on the above specific design, there is an assembly surface between the guide vane 6 and the insulating seat 13. Through the cooperation of the assembly surface, the guide vane 6 is fixedly assembled on the top of the canned motor 1 by bolts. Even if liquid enters, it also serves as an insulating effect. And based on the assembly and seal of the pump casing 2 and the canned motor 1, its sealing effect can be effectively guaranteed, thereby reducing the installation requirements.

[0039] As a more specific design, through holes are also provided on the impeller 5, and these through holes can lead the coolant to the insulating seat 13, thereby further cooling the insulating seat 13. Through this design, the cooling effect inside the entire pump casing 2 can be effectively achieved.

[0040] As a more specific design, the water inlet pipe 16 and the water outlet pipe 17 are the same pipe orifice, and a partition plate is provided inside this pipe orifice to form the water inlet pipe 16 and the water outlet pipe 17. In the design of this structure, this structure design has not been adopted in the current design of nuclear pumps. However, based on the design requirements of this structure, this structure design method is adopted in the specific structure design. At the same time, it can effectively ensure the effect of the overall structure and meet the requirements of the compact structure design.

[0041] To sum up:

[0042] 1. A compact small reactor main pump structure of the present invention adopts an integrated pump casing structure. In the internal structural design, the structure of the entire cavity is fully divided to achieve the full utilization of the entire space. In terms of space utilization, it can be fully utilized, and further, the compact design of the main pump can be realized, thus fully meeting the usage requirements of the compact reactor coolant pump system;

[0043] 2. A compact small reactor main pump structure of the present invention has the inlet and outlet arranged in the same pipeline and divided into two halves. The coolant flows in from one half of the pipeline and enters the large ring cavity. A partition is arranged in the ring cavity to achieve the diversion of the coolant before the impeller inlet. With the reasonable design of the pipeline structure, the application of the integrated pump casing structure is effectively realized, so that this structure can be fully applied;

[0044] 3. A compact small reactor main pump structure of the present invention, with the structural design of the integral guide vane, impeller, and conduit, can effectively realize the circulation of the coolant inside the whole and maintain the cooling effect of the whole main pump. At the same time, with the design of the heat insulation pad, the integrated pump casing and the canned motor form the pressure boundary of the reactor coolant system, ensuring the actual application effect of this design.

[0045] The present invention is not limited to the foregoing specific embodiments. The present invention extends to any new feature or any new combination disclosed in this specification, as well as any new method or process step or any new combination disclosed.

Claims

1. A compact small reactor main pump structure, characterized by: The invention comprises a pump casing (2) assembled on the top of a canned motor (1); the pump casing (2) is provided with a chamber for cooling medium circulation on the inner side thereof located above the canned motor (1); the chamber comprises a water inlet chamber (3) located at the top and a cooling chamber (4) located at the bottom and above the canned motor (1); the water inlet chamber (3) is connected to a water inlet pipe (16); the cooling chamber (4) is connected to a water outlet pipe (17); an impeller (5) and a guide vane (6) are provided in the cooling chamber (4).

2. A compact small reactor main pump structure as claimed in claim 1, characterized in that: The pump housing (2) is assembled on the top of the canned motor (1) by means of bolts, and a sealing structure is provided on the assembled joint surface after assembly, and the sealing structure comprises a sealing gasket (7) and a C-shaped sealing ring (8).

3. A compact small reactor main pump structure as claimed in claim 2, characterized in that: The upper and lower side surfaces of the C-shaped sealing ring (8) are fixed by welding.

4. A compact small reactor main pump structure as claimed in claim 1, characterized in that: A partition plate (9) is provided in the water inlet chamber (3) for dividing the coolant before the inlet of the impeller (5).

5. A compact small reactor main pump structure as claimed in claim 1, characterized in that: A conduit (10) is provided above the impeller (5) and at the junction of the water inlet chamber (3) and the cooling chamber (4) to form an impeller (5) inlet for guiding the coolant to the impeller (5).

6. A compact small reactor main pump structure as claimed in claim 5, characterized in that: A guide vane (6) is provided at the bottom of the bottom of the duct (10), and the impeller (5) drives the coolant to flow out from the guide vane (6) and out through the outlet pipe (17). The guide vane (6) is fixedly assembled and shielded at the top of the motor (1).

7. A compact small reactor main pump structure as claimed in claim 5, characterized in that: There is a mounting surface between the guide tube (10) and the guide vane (6), and an open ring (11) is arranged on the mounting surface as a seal.

8. A compact small reactor main pump structure as claimed in claim 5, characterized in that: A front sealing ring (12) is also provided between the guide vane (6) and the impeller (5).

9. A compact small reactor main pump structure as claimed in claim 1, characterized in that: The impeller (5) is mounted on the rotor of the shielded motor (1); a heat insulation seat (13) is provided below the impeller (5); a heat insulator (14) is provided between the heat insulation seat (13) and the top of the shielded motor (1); and a rear sealing ring (15) is provided between the impeller (5) and the heat insulation seat (13).

10. A compact small reactor main pump structure as claimed in claim 1, characterized in that: The water inlet pipe (16) and the water outlet pipe (17) are the same pipe opening, and a dividing plate is arranged in the pipe opening, thereby forming the water inlet pipe (16) and the water outlet pipe (17).

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