Auxiliary Placing Device for the Pump Casing of the Nuclear Power Main Pump

Abstract

The present invention relates to the field of processing of the pump casing of a nuclear power main pump, and discloses a turnover and placement device for the pump casing of a nuclear power main pump. The auxiliary placement device for the pump casing of a nuclear power main pump disclosed by the present invention includes a support base, a transverse connection structure and a fixing structure. The fixing structure includes an upper bottom plate, a lower bottom plate and a fixing shaft connected between the upper bottom plate and the lower bottom plate. The diameter of the fixing shaft is adapted to the diameter of the corresponding bottom foot support ear hole of the pump casing. The sizes of the upper bottom plate and the lower bottom plate are both larger than the diameter of the corresponding bottom foot support ear hole of the pump casing. The lower bottom plate is detachably connected to the fixing shaft. The transverse connection structure is connected between the support base and the upper bottom plate of the fixing structure. The distance between the support base and the fixing structure is greater than the axial distance between the center of gravity of the corresponding pump casing and the bottom foot support ear hole. The auxiliary placement device for the pump casing of the present application cleverly uses the bottom foot support ear hole of the pump casing itself to install the auxiliary placement device, compensates for the asymmetric structure at the lower part of the pump casing, so that the pump casing can be stably placed in the state where the side hole faces upward.

Description

Technical Field

[0001] The present invention relates to the field of processing of nuclear power main pump casings, and particularly to a turnover and placement device for a nuclear power main pump casing. Background Art

[0002] The nuclear power main pump is a pump used to drive the coolant to circulate within the RCP (Reactor Coolant System) in the primary loop system of the nuclear island. The main pump is located at the heart of the nuclear island and is used to pump hot water into the evaporator to convert thermal energy. It is the key to controlling the water circulation in nuclear power operation. Each steam generator has a main pump, and there is a corresponding nuclear power pump casing.

[0003] The function of the main pump casing (hereinafter referred to as the pump casing) is to enclose the impeller in a fixed space so as to suck and press out the liquid through the action of the impeller. Since the cross-sectional area of the flow passage gradually expands, the high-speed liquid thrown out from around the impeller gradually reduces its flow velocity, effectively converting part of its kinetic energy into static pressure energy. The pump casing not only collects the water body thrown out by the impeller but also is an energy conversion device.

[0004] The pump casing is an integral formed by surfacing stainless steel on the inner wall of the pump casing forging and then assembling and welding the bottom corner assembly and the safety end assembly. Its main manufacturing processes are as follows:

[0005] Forging manufacturing - Inner wall surfacing - Machining (after welding) - Assembling and welding the bottom foot assembly and the safety end assembly - Machining (before hydrostatic test) - Hydrostatic test - Machining (after hydrostatic test)

[0006] In the above manufacturing process, the pump casing mainly undergoes the following 4 orientations as Figures 1-4 shown. The 4 pump casing placement forms shown in the figure are the operating postures that must be achieved during the manufacturing process of the pump casing, including 1. The large end face is upward, 2. The large end face is downward, 3. The side hole is upward, and 4. The side hole is downward. And during the processes such as inner wall surfacing of the pump casing and assembling and welding the safety end assembly (water outlet), the water outlet needs to be turned to the upward position (i.e., the side hole of form 3 is upward). At the same time, it can be seen from the figure that when placed with the side hole upward (form 3), the lower bottom corner of the pump casing is an asymmetric structure and there is no clear support position at the lower part, and the existing state cannot achieve the placement. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide an auxiliary placement device for a nuclear power main pump casing, which solves the problem of placing the pump casing with the side hole upward.

[0008] The auxiliary placement device for the pump casing of the nuclear power main pump disclosed in the present invention includes a support base, a transverse connection structure, and a fixing structure. The fixing structure includes an upper base plate, a lower base plate, and a fixing shaft connected between the upper base plate and the lower base plate. The diameter of the fixing shaft is adapted to the diameter of the corresponding pump casing bottom foot support ear hole. The sizes of the upper base plate and the lower base plate are both larger than the diameter of the corresponding pump casing bottom foot support ear hole. The lower base plate is detachably connected to the fixing shaft. The transverse connection structure is connected between the support base and the upper base plate of the fixing structure. The distance between the support base and the fixing structure is greater than the axial distance between the center of gravity of the corresponding pump casing and the bottom foot support ear hole.

[0009] Preferably, the fixing structure further includes a transition sleeve, which is detachably sleeved on the fixing shaft. The diameter of the fixing shaft is adapted to the diameter of the corresponding pump casing bottom foot support ear hole before processing. The inner diameter of the transition sleeve is adapted to the fixing shaft, and the outer diameter of the transition sleeve is adapted to the diameter of the corresponding pump casing bottom foot support ear hole after processing.

[0010] Preferably, the outer end of the fixing shaft has a connecting screw. The lower base plate is sleeved on the connecting screw, and a fixing nut is connected to the outside of the lower base plate on the connecting screw.

[0011] Preferably, the outer end face of the fixing shaft is a conical guiding surface.

[0012] Preferably, the support base includes a top pump casing support structure, a middle support structure, and a bottom ground support structure. The middle support structure is connected between the top pump casing support structure and the bottom ground support structure.

[0013] Preferably, the bottom ground support structure includes at least two parallel support beams, which are connected by connecting pieces. The length of the support beams is greater than the length of the middle support structure. An inclined brace is provided between the ends of the support beams and the middle support structure.

[0014] Preferably, the middle support structure includes multiple vertical support members, and the top pump casing support structure is a frame structure and is connected to the tops of the vertical support members.

[0015] Preferably, a protective pad is provided on the top surface of the top pump casing support structure.

[0016] Preferably, the transverse connection structure includes at least two transverse support columns, which are arranged symmetrically about the circumferential center on the upper base plate.

[0017] Preferably, the middle support structure includes multiple vertical support members, and connecting plates are provided on the sides of the vertical support members. The transverse support columns are connected to the connecting plates.

[0018] The beneficial effects of the present invention are as follows: The auxiliary placement device for the nuclear power main pump casing ingeniously utilizes the bottom foot support ear holes of the casing itself to install the auxiliary placement device, compensating for the asymmetric structure at the lower part of the casing, so that the casing can be stably placed with the side holes facing upwards, meeting the production and placement requirements of various processes such as welding, machining, and flaw detection during the manufacturing process of the casing. During the execution of each manufacturing process, there is no need to disassemble the auxiliary placement device, and each manufacturing process can be rapidly advanced. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figures 1-4 are schematic diagrams of four placement postures of the pump casing;

[0020] Figure 5 is a three-dimensional schematic diagram of the auxiliary placement device for the nuclear power main pump casing;

[0021] Figure 6 is a top view schematic diagram of the auxiliary placement device for the nuclear power main pump casing;

[0022] Figure 7 is Figure 6 the B - B cross-sectional view in

[0023] Figure 8 is a schematic diagram of the setting of the transition sleeve;

[0024] Figure 9 is Figure 6 the A - A cross-sectional view in

[0025] Figure 10 is a side view schematic diagram of the auxiliary placement device for the nuclear power main pump casing;

[0026] Figure 11 is a usage schematic diagram of the auxiliary placement device for the nuclear power main pump casing.

[0027] Reference numerals: pump casing 1, bottom foot support ear hole 11, support seat 2, top pump casing support structure 21, middle support structure 22, bottom ground support structure 23, inclined strut 24, transverse connection structure 3, transverse support column 31, fixing structure 4, upper base plate 41, fixing shaft 42, lower base plate 43, connecting screw 44, fixing nut 45, transition sleeve 46. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] The present invention will be further described below.

[0029] As Figures 5-10As shown, the nuclear power main pump casing auxiliary placement device disclosed in the present invention includes a support seat, a transverse connecting structure and a fixing structure, the fixing structure includes an upper base plate, a lower base plate and a fixing shaft connected between the upper base plate and the lower base plate, the fixing shaft is adapted to the diameter of the corresponding pump casing foot support ear hole, the sizes of the upper base plate and the lower base plate are both larger than the diameter of the corresponding pump casing foot support ear hole, the lower base plate and the fixing shaft are detachably connected, the transverse connecting structure is connected between the support seat and the upper base plate of the fixing structure, and the distance between the support seat and the fixing structure is larger than the axial distance between the center of gravity of the corresponding pump casing and the foot support ear hole.

[0030] When the side hole of the nuclear power main pump casing is facing upward, the structure of the pump casing in this application determines that it cannot be placed stably. The flat side of the pump casing foot lug itself is a fulcrum. It is only necessary to design a fulcrum on its left side, and this fulcrum is flush with the flat side of the foot lug. Due to the characteristics of the flip platform, the pump casing can rotate 90° at a time during the turning process. In order to ensure that the support seat does not fall off and other safety hazards during the turning process of the pump casing, the support seat needs to be fixed. However, the support seat cannot be independently fixed on the flip platform beam, because the support seat cannot leave the flip platform after being fixed on the flip platform beam. Once the pump casing leaves the flip platform, it cannot be placed stably, and the placement problem of the pump casing cannot be solved. This application makes full use of the pump casing foot lug hole to design and manufacture an auxiliary placement device.

[0031] like Figure 11 As shown, when the present application is used, first disassemble the lower base plate of the fixed structure, insert the fixed shaft into the pump casing foot lug hole, then install the lower base plate on the fixed shaft, and clamp the upper base plate and the lower base plate on both sides of the pump casing foot lug. The matching of the diameter of the fixed shaft and the corresponding pump casing foot lug hole means that the fixed shaft can be inserted exactly into the pump casing foot lug hole without causing a large shake, thereby ensuring the stability of the auxiliary placement device installed on the pump casing. The function of the transverse connection structure is to keep the support seat away from the pump casing foot lug hole, and the distance between the support seat and the fixed structure is greater than the axial distance between the center of gravity of the corresponding pump casing and the foot lug hole. The center of gravity of the pump casing is located between the support seat and the pump casing foot lug, so that the pump casing of the nuclear power main pump can be stably placed under the support of the auxiliary placement device.

[0032] The size of the foot support ear hole of the pump casing is different before and after processing. For example, the diameter of the foot support ear hole of a pump casing is φ180mm before processing and φ221mm after processing. In order to support the pump casing at the foot support ear hole, the same auxiliary placement device can be used for support placement, such as Figure 8As shown, in the preferred embodiment of the present application, the fixing structure further includes a transition sleeve, which is detachably sleeved on the fixing shaft. The fixing shaft is adapted to the diameter of the corresponding pump housing bottom foot support ear hole before processing. The inner diameter of the transition sleeve is adapted to the fixing shaft, and the outer diameter of the transition sleeve is adapted to the diameter of the corresponding pump housing bottom foot support ear hole after processing. When assisting in placing the pump housing before processing the bottom foot support ear hole, the transition sleeve is not assembled, and the fixing shaft is directly inserted into the bottom foot support ear hole to achieve connection. When assisting in placing the pump housing after processing the bottom foot support ear hole, the transition sleeve is assembled onto the fixing shaft and then inserted into the bottom foot support ear hole to achieve connection. For example, for the bottom foot support ear hole with a diameter of φ180mm before the aforementioned processing, the diameter of the fixing shaft is φ178mm, and for the bottom foot support ear hole with a diameter of φ221mm after processing, the diameter of the transition sleeve is φ219.5mm. The fixing shaft and the transition sleeve are respectively adapted to the front and back of the bottom foot support ear hole, so that the same set of auxiliary placement devices can be used for auxiliary support and placement.

[0033] The connection between the lower bottom plate and the fixing shaft can be bolt connection or pin connection. In the preferred embodiment of the present application, the outer end of the fixing shaft has a connecting screw. The lower bottom plate is sleeved on the connecting screw, and a fixing nut is connected to the outside of the lower bottom plate on the connecting screw. In this application, the fixing shaft is inserted into the bottom foot support ear hole, and the fixing shaft bears the shear force, rather than the connecting screw bearing the shear force. Therefore, a smaller connecting screw can be used. Compared with a large-diameter screw, there is a large operation space without a special torque wrench, which can reduce the operation difficulty. Moreover, even if the connecting screw is damaged, the internal fixing shaft and transition sleeve can still achieve support, which can achieve a double-insurance effect.

[0034] The diameter of the fixing shaft of the auxiliary placement device is adapted to the diameter of the bottom foot support ear hole, and the difference between the two diameters is not large. In order to facilitate the insertion of the fixing shaft into the bottom foot support ear hole, in the preferred embodiment of the present application, the outer end face of the fixing shaft is a conical guiding surface. When inserting the fixing shaft into the bottom foot support ear hole, the guiding of the conical guiding surface can be used to reduce the difficulty of insertion.

[0035] The function of the support seat is to support between the pump housing and the ground, forming another fulcrum of the pump housing. The most important thing for the support seat is to meet the strength requirements. In the preferred embodiment of the present application, the support seat includes a top pump housing support structure, a middle support structure, and a bottom ground support structure. The middle support structure is connected between the top pump housing support structure and the bottom ground support structure. The top pump housing support structure is used to contact and support the pump housing, the bottom ground support structure is used to contact and support the ground, and the middle support structure is used to connect the top pump housing support structure and the bottom ground support structure to make the support reach an appropriate height.

[0036] In a preferred embodiment of the present application, the bottom ground support structure includes at least two parallel support beams, which are connected by connecting members. The length of the support beams is greater than the length of the middle support structure, and diagonal braces are provided between the ends of the support beams and the middle support structure. As Figure 11 shown, due to the limitation of the pump casing structure lugs, the sizes of the top pump casing support structure and the middle support structure are limited. In order to achieve the purpose of stable support, the length of the support beams of the bottom ground support structure is lengthened in this embodiment, and the diagonal braces are used to strengthen the stress intensity at the ends.

[0037] The middle support structure bears a large vertical load. In order to make it have the functions of being lighter in weight and greater in strength, in a preferred embodiment of the present application, the middle support structure includes multiple vertical support members, and the top pump casing support structure is a frame structure and is connected to the top of the vertical support members. As Figure 5 shown in the embodiment, the number of vertical support members is 4. If greater strength requirements are needed, more vertical support members can be provided. The top pump casing support structure of the frame structure can play a role in connecting and stabilizing the top of the vertical support members, and at the same time is beneficial to placing the pump casing on it. In order to prevent damage to the pump casing, a protective pad can also be provided on the top surface of the top pump casing support structure. The protective pad can be made of materials such as waste rubber.

[0038] The transverse support columns, that is, the aforementioned vertical support members or even the entire support base, can all be made of section steel. As Figure 5 shown in the embodiment, angle steel is used. The strength of the section steel is relatively low at certain angles. Since the length of the transverse support column is relatively long, in a preferred embodiment of the present application, the transverse connection structure includes at least two transverse support columns, and the transverse support columns are arranged symmetrically along the circumferential center on the upper bottom plate. Such an arrangement can ensure that the transverse connection structure has good strength and stiffness in the circumferential direction. When the middle support structure adopts multiple vertical support members, in order to facilitate the connection of the vertical support members, connecting plates are provided on the sides of the vertical support members, and the transverse support columns are connected to the connecting plates.

Claims

1. Auxiliary placement device for the pump casing of a nuclear power main pump, characterized in that It includes a support base, a transverse connection structure and a fixing structure. The fixing structure includes an upper base plate, a lower base plate and a fixing shaft connected between the upper base plate and the lower base plate. The diameter of the fixing shaft is adapted to the diameter of the bottom foot ear hole of the corresponding pump casing. The sizes of the upper base plate and the lower base plate are both larger than the diameter of the bottom foot ear hole of the corresponding pump casing. The lower base plate is detachably connected to the fixing shaft. The transverse connection structure is connected between the support base and the upper base plate of the fixing structure. The distance between the support base and the fixing structure is greater than the axial distance between the center of gravity of the corresponding pump casing and the bottom foot ear hole.

2. The auxiliary placement device for the pump casing of the nuclear power main pump according to claim 1, characterized in that: The fixing structure further includes a transition sleeve, which is detachably sleeved on the fixing shaft. The diameter of the fixing shaft is adapted to the diameter of the bottom foot ear hole of the corresponding pump casing before machining. The inner diameter of the transition sleeve is adapted to the fixing shaft, and the outer diameter of the transition sleeve is adapted to the diameter of the bottom foot ear hole of the corresponding pump casing after machining.

3. The auxiliary placement device for the nuclear power main pump casing according to claim 1, wherein: The outer end of the fixing shaft has a connecting screw, the lower base plate is sleeved on the connecting screw, and a fixing nut is connected to the outside of the lower base plate on the connecting screw.

4. The auxiliary placement device for the nuclear power main pump casing according to claim 1, characterized in that: The outer end face of the fixing shaft is a conical guiding surface.

5. The auxiliary placement device for the pump casing of the nuclear power main pump according to claim 1, wherein: The support base includes a top pump casing support structure, a middle support structure and a bottom ground support structure. The middle support structure is connected between the top pump casing support structure and the bottom ground support structure.

6. The auxiliary placement device for the pump casing of the nuclear power main pump according to claim 5, wherein: The bottom ground support structure includes at least two parallel support beams, which are connected by connecting pieces. The length of the support beam is greater than the length of the middle support structure. An inclined brace is provided between the end of the support beam and the middle support structure.

7. The auxiliary placement device for the nuclear power main pump casing according to claim 5, characterized in that: The middle support structure includes multiple vertical support members, and the top pump casing support structure is a frame structure and is connected to the top of the vertical support members.

8. The auxiliary placement device for the pump casing of the nuclear power main pump according to claim 5, characterized in that: A protective pad is provided on the top surface of the top pump casing support structure.

9. The auxiliary placement device for the pump casing of the nuclear power main pump according to claim 5, wherein: The transverse connection structure includes at least two transverse support columns, which are arranged symmetrically about the circumferential center on the upper base plate.

10. The auxiliary placement device for the pump housing of the nuclear power main pump according to claim 9, characterized in that: The middle support structure includes multiple vertical support members, a connecting plate is provided on the side of the vertical support member, and the transverse support column is connected to the connecting plate.

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