WO2013143446A1

WO2013143446A1 - Charging pump for nuclear power plant

Info

Publication number: WO2013143446A1
Application number: PCT/CN2013/073211
Authority: WO
Inventors: 陆金琪; 毛燕萍
Original assignee: 上海阿波罗机械股份有限公司
Priority date: 2012-03-27
Filing date: 2013-03-26
Publication date: 2013-10-03
Also published as: CN102606484A

Abstract

A charging pump for a nuclear power plant comprises a stator member (1), a rotor member (2), a bearing member, and a shaft seal device (4). The stator member (1) comprises a pump head (11), a cylindrical body, and a tail plate (14). The cylindrical body comprises an outer shell (13) and an inner shell (12). The rotor member (2) comprises a rotating shaft (20), an impeller sleeved on the rotating shaft (20), an intermediate shaft sleeve (24), a front shaft sleeve (25), a thrust disc (26), a positioning sleeve (27), and a rear bearing sleeve (28). The bearing member comprises a driving end bearing (31), an intermediate auxiliary bearing (32), and a non-driving end bearing (33). The charging pump for a nuclear power plant can reduce the volume of a pump.

Description

A charge pump for a nuclear power plant

Technical field

The invention relates to an upper charging pump for a nuclear power plant, in particular to an upper charging pump for a nuclear power plant. Background technique

The upper charge pump is an important part of the chemical and volume control system (RCV). The main functions of the charge pump are as follows:

1) providing a water-filled flow to the reactor coolant system to maintain a normal level in the regulator;

2) Provide cooling water to the No. 1 seal of the three reactor coolant pumps, which also acts to prevent high temperature coolant from leaking through the seal;

3) Used as a safety injection pump to prevent the core from being exposed in the water loss event (L0CA).

The charge pumps currently used in nuclear power plants are usually horizontal, double-shell, multi-stage centrifugal pumps. When the centrifugal pump runs at high speed, it will generate a large axial force. In addition, according to the requirements of the nuclear power plant system, there are five working conditions for the hydraulic performance of the upper charging pump, the flow range span is large, and the total pressure head of the pump is high, and The working flow is very small, and the upper charging pump is a low specific speed pump in the centrifugal pump. The flow path of the impeller and the vane is narrow, which makes the design of the hydraulic component very difficult. In addition, the charging pump requires multiple flow conditions. It can work, its span range greatly exceeds the range of general centrifugal pumps, especially the small flow requires no unstable zone (no hump), so it is necessary to develop a rotor component that can meet the special performance requirements of the five working conditions of the upper charging pump. This multistage centrifugal pump has the following drawbacks:

1) The inlet and outlet nozzles are all set on the outer cylinder. In addition, mechanical seals are provided at both ends of the pump. In particular, the pressure on the high-pressure mechanical seal is relatively large. Both ends must be provided with an external mechanical seal flushing line. Therefore, the volume is generally large, occupying a large space of the factory;

2) The inner and outer shells are mostly of integral structure, and the inner shells are mostly fixed at both ends. When the pump is under thermal transient conditions, the pump unit, especially the inner casing, may be hot due to the sudden change of the medium temperature of the inner casing. The cause of expansion and contraction is a certain problem such as a certain displacement in the axial direction. In addition, the overall structure of the inner casing may cause the inner flow passage to be long, which makes the inner flow passage clear and sand inconvenient, and the overall casting difficulty is high;

3) The connection of the flow passage between the impellers is mostly realized by the guide vanes or the long flow passages. The connection of the flow passages between the impellers is mostly realized by the guide vanes or the long flow passages, which is inconvenient for processing and no damage inspection;

4) The multi-stage guide vanes are usually connected by screws, 0-rings, etc., which not only makes the structure of the pump complicated, but also inconvenient to disassemble and repair; and because the medium conveyed by the upper charge pump contains radioactive substances, this is undoubtedly Increased the maintenance person The risk of ingesting radioactive material;

5) The support is often supported by two points, that is, a bearing is provided by the pump drive end and the non-drive end, so that the rigidity of the shaft is not high enough, which affects the working efficiency of the upper charge pump. Summary of the invention

SUMMARY OF THE INVENTION The object of the present invention is to overcome the deficiencies of the prior art and to provide a charging pump for a nuclear power plant, which can reduce the volume of the pump, meet the special performance requirements of the upper charging pump, and has high working efficiency.

A technical solution for achieving the above object is: a charging pump for a nuclear power plant, comprising a stator component, a rotor component, a bearing component, and a shaft sealing device. The stator component includes a pump head, a cylinder body and a tail plate, and the cylinder body includes a casing And the inner casing, the rotor component comprises a rotating shaft and an impeller, an intermediate bushing, a front bushing, a thrust disc, a positioning sleeve and a rear bearing sleeve, which are arranged on the rotating shaft, wherein the bearing component comprises a driving end bearing and an intermediate auxiliary bearing And a non-drive end bearing, wherein: the pump head comprises a main body portion of the disc structure and having an axial hole, an inlet hole and an outlet hole;

The outer casing of the cylinder is fixed on a rear end surface of the pump head, and the inner cavity of the outer casing comprises an inner casing cavity located in a front portion and a rear bearing cavity located in a rear small portion;

The inner casing of the cylinder is a radially split structure and includes a first plate connected in series, a pump head side fluid guide, an intermediate section, a cylinder side fluid guide, a tail cover and a rear bearing cover, the first plate, The pump head side fluid guiding body, the intermediate section, the cylinder side guiding fluid and the tail cap are connected to each other to have a complete cavity for accommodating the impeller;

a first plate of the inner casing of the stator component is fixed on a rear end surface of the pump head such that the first plate, the pump head side fluid guide, the intermediate section, the cylinder side fluid guide, and the front half of the tail cap are located In the inner casing cavity of the outer casing, the rear half of the tail cap and the rear bearing cap are located in the rear bearing cavity of the outer casing, and the rear end surface of the rear bearing cap and the front end of the tail plate The mask has a free space;

The impeller in the rotor component is composed of a twelve-stage impeller including a first-stage impeller, two- to four-stage impellers, and five to twelve-stage impellers, and the water inlet of the first four-stage impeller points to the upper accumulator a driving end of the pump, the rear eight-stage impeller and the first four-stage impeller are arranged back to back; the intermediate shaft is sleeved between the fourth-stage impeller and the fifth-stage impeller; the front bushing, the thrust plate and the positioning a sleeve is disposed in front of the first stage impeller; the rear bearing sleeve is disposed at a rear portion of the tenth second stage impeller;

The drive end bearing includes an upper bearing cap, a lower bearing body, front and rear bearing end caps, a double-sided thrust bearing, a sliding bearing, two oil seal chambers and two floating seals, the upper bearing cap and the lower bearing body Connected to the front end surface of the pump head and integrated by the front and rear bearing end covers to form a bearing chamber; the double-sided thrust bearing is disposed at a bearing chamber is located at a front and rear end faces of the thrust disc; the sliding bearing is disposed in the bearing chamber and located at a front portion of the double-sided thrust bearing; the two oil seal chambers are disposed in the bearing chamber And respectively located at a rear portion of the double-sided thrust bearing and a front portion of the sliding bearing; the two floating seals are disposed one by one in the two oil seal chambers;

The intermediate auxiliary bearing is a hydrostatic bearing and is disposed between the fourth stage impeller and the fifth stage impeller. The front part of the inner surface of the intermediate auxiliary bearing is circumferentially distributed with a plurality of rectangular water chambers.

The non-drive end bearing is also a hydrostatic bearing and is disposed at the rear of the ground 12-stage impeller. The central portion of the inner surface of the non-driving end bearing is circumferentially arranged with a plurality of I-shaped water chambers;

The shaft sealing device is a cartridge type mechanical seal that is mounted on the rotating shaft and located at the front of the axial bore of the pump head.

The above-mentioned upper charging pump for a nuclear power plant, wherein an axial hole on the pump head is opened at a center of front and rear end faces of the main body portion, and an inlet hole on the pump head is opened on an outer peripheral surface of the main body portion and is connected by up and down The upper portion of the inlet hole is perpendicular to the axial hole, the lower portion of the inlet hole forms an obtuse angle with the upper portion of the inlet hole, and the lower opening of the lower portion of the inlet hole is located at the rear end surface of the main body portion The outlet hole on the pump head is opened at 180° to the lower portion of the inlet hole on the outer peripheral surface of the main body portion and communicates with the axial hole;

The above-mentioned upper charging pump for a nuclear power plant, wherein a rear end surface of the first plate is provided with a semi-spiral vortex chamber symmetrically arranged at 180°; the pump side fluid guiding body is composed of three-section unit fluid guiding body, each section a semi-spiral vortex chamber arranged symmetrically at 180° is respectively disposed on the front and rear end faces of the unit flow guiding body; a semi-spiral vortex chamber symmetrically arranged at 180° is respectively disposed on the front and rear end faces of the intermediate portion; The body side fluid guide is composed of a seven-section unit fluid guide and is mounted opposite to the pump head side fluid guide; the front end surface of the tail cover is provided with a semi-spiral vortex chamber arranged symmetrically at 180°; The rear end surface, the front and rear end faces of each unit of the fluid guiding body, the front and rear end faces of the middle section, and the front end surface of the tail cap respectively respectively open corresponding positioning pin holes and connecting through holes; the first plate and the pump head side are fluid-conducting Between the three-section unit fluid and the intermediate section, the pin hole on the rear end surface of the previous unit of the fluid guide is radially positioned relative to the pin hole on the front end surface of the subsequent unit of the fluid guide and passes through the connection. Hole pull The stud and the nut axially lock the three-unit fluid guiding body and the middle section of the first plate and the pump head side fluid guiding body; the intermediate section, the seven-section unit guiding fluid of the cylinder side guiding fluid and the tail cap pass the pin The pin hole on the rear end face of the previous unit of the fluid guide is radially positioned with respect to the pin hole on the front end face of the subsequent unit of the fluid guide and passes through a tension stud and nut passing through the connection through hole to the middle section, The seven-section unit fluid guiding body and the tail cap of the cylinder side guiding fluid are axially locked.

The above-mentioned upper auxiliary pump for a nuclear power plant, wherein the intermediate auxiliary bearing is composed of a cylinder and a flange connected to one end of the cylinder, and a central tank and a rear portion of the inner surface of the cylinder respectively have a back sink and a Seal the sink, and at each moment a water inlet hole is defined in the center of the bottom surface of the water-shaped cavity, and a plurality of water outlet holes are formed in the front end surface of the cylinder, and the outer surface of the cylinder is opened with the sealing water tank. Connected oblique holes.

In the above-mentioned upper charging pump for a nuclear power plant, a water inlet hole is radially opened in a central portion of a bottom surface of each of the I-shaped water chambers on the non-driving end bearing.

The above-mentioned upper charging pump for a nuclear power plant, wherein the shaft sealing device comprises a machine sleeve, a pressure plate, a rotating ring, a stationary ring seat, a static ring, a pressure ring, a plurality of springs and a throttle bushing, the machine sealing shaft The sleeve includes a sleeve body and a sleeve connected to the rear end of the sleeve body. The front end surface of the sleeve is provided with a ring groove, and the machine sleeve is fixedly mounted on the rotating shaft through the locking plate; the pressure plate includes a a flange and a sleeve connected to the rear end surface of the flange, the front end surface of the flange is provided with a dimple, and the inner cavity surface of the sleeve is a stepped surface of the outer high and the inner low, on the outer step surface of the sleeve a plurality of blind holes are uniformly disposed; the pressure plate is fixed on the outside of the sleeve body of the machine seal sleeve with a flange gap, and the sleeve is sleeved outside the sleeve of the machine seal sleeve. a front end surface of the pump head; the rotating ring is fixed in a ring groove of the machine sleeve; the static ring seat is axially movably mounted in a cavity of the sleeve of the pressure plate; a ring mounted on a lumen of the sleeve of the pressure plate and fixed to a rear end surface of the stationary ring seat; a pressure ring is disposed at an outer end of the static ring and fixed to a rear end surface of the static ring seat; the plurality of springs are placed one by one in a blind hole of the pressure plate, and a rear end of the plurality of springs is connected to the a front end surface of the stationary ring seat such that a rear end surface of the stationary ring is always in contact with a front end surface of the rotating ring; and the throttle bushing is installed in a recess of the pressure plate.

In the above-mentioned upper charging pump for a nuclear power plant, the outer peripheral surface of the main body portion is further provided with a machine-sealed flushing hole communicating with the axial hole.

The above-mentioned upper charging pump for a nuclear power plant, wherein a flushing hole communicating with the inner cavity of the sleeve is further formed on a rear end surface of the flange of the pressure plate.

The above-mentioned upper charging pump for a nuclear power plant, wherein a front surface of the sleeve body is provided with a card slot, and a positioning piece is engaged in the card slot to abut the pressing plate against the positioning piece On the back end.

The charging pump for the nuclear power plant of the invention has the following structural features:

1) The overall structure of the pump is double housing, single bearing oil lubrication, single mechanical seal, high pressure side integral seal. The cylinder, pump head and tail plate form a pressure boundary. There is no opening on the cylinder, because the pressure boundary adopts a completely symmetrical cylindrical integral forging, the processing difficulty is reduced during the manufacturing process, and the non-destructive flaw detection is facilitated;

2) The pump head is forged as a whole, the inlet and outlet flanges are on the same center line and distributed on both sides of the pump head; the welding position of the pump head and the inlet and outlet flanges is in the form of a convex round tube structure, which facilitates the inspection of the welded parts. ;

3) The pump core component is a radial split structure, and the non-drive end axial direction of the pump core component is free, in the accident condition Lower, capable of withstanding the axial extension of thermal expansion;

4) The guide body is positioned by the pin, and the bolt and the nut are loosened during maintenance. It is convenient to clean the guide fluid, and the maintenance and assembly are convenient and simple;

5) The fluid guide is an integral casting, adopting a 180° symmetrical semi-helical vortex chamber structure, and the radial force generated by the impeller during operation is automatically balanced; the fluid guide is a radial split structure, which can improve the surface roughness by grinding the surface of the runner , improve the efficiency of the pump, the flow passage is easier to clean during maintenance, the possibility of adhering to the radiation medium is reduced, and the safety of the maintenance personnel is ensured;

6) The fitting of each part on the rotor part and the shaft is clearance fit. The impellers of each stage are positioned by the snap ring. When the parts on the rotor parts are disassembled, no heating is required to avoid evaporation of contaminants. Convenient to flush the contaminants in the gap during maintenance. , to ensure the safety of maintenance personnel;

7) The pump has a total of twelve stages of impellers. The first four stages of impeller inlets point to the coupling, and the rear eight stages of impellers are symmetrically arranged back-to-back with the first four stages of impellers. The pressure at the end of the shaft is the pressure of the fourth stage impeller outlet, residual axial force. It is supported by the double-sided thrust bearing, which avoids the setting of the balance mechanism, and the accident that the axial force balance mechanism is engaged and the shaft is broken will never occur;

8) Using three impeller combinations, the first stage impeller should take into account the anti-cavitation performance, and the five to twelve-stage impellers take into account the steep drop characteristics of the pump flow-lift curve, which is skillfully combined to meet the special performance requirements of the upper charge pump;

9) The pump body sealing ring matched with the front and rear ring of the impeller adopts a labyrinth seal to ensure no contact between the rotor component and the stator component, and can withstand thermal shock and wear against particulate water under accident conditions;

10) Auxiliary support bearings are arranged between the fourth stage and the fifth stage impeller and the pump non-drive end, which form a three-point support to the rotor component with the oil-lubricated bearing of the pump drive end to ensure that the rotor is rigid under any working condition;

11) The non-drive end of the pump is closed with a tail plate, reducing one shaft seal and oil lubricated bearings. The advantages are as follows: a) There is no need to set a balanced water pipe, which reduces the instability of the pump operation caused by the blockage of the balance water pipe; b) the risk of leakage of the shaft seal without the machine seal, and the repair time and cycle brought by the replacement of the machine seal ; c) reduced the amount of lubricant piping and lubricant;

d) Reduce the failure point of a bearing system to start without pre-lubrication and improve the operational reliability of the pump.

12) The pump drive end is provided with a double-sided thrust bearing that receives axial force and a sliding bearing that receives radial force. An oil seal chamber and a floating seal are provided on the outside of the thrust bearing and the plain bearing. Once the pump is initially operated, the lubricating oil is stored between the oil seal chamber and the floating seal, so that the pre-lubrication start is very simple;

13) The shaft seal of the pump adopts the built-in mechanical seal structure and adopts the self-flushing scheme; the machine seal flushing water pipeline and the cyclone separator are ingeniously designed on the pump head, and there is no pipeline outside, and the safety hazard is reduced. Mechanical seal plate A throttle bushing is provided above, and even if the mechanical seal fails, the shaft seal leakage of the pump is less than the minimum requirement. DRAWINGS

1 is a schematic structural view of a charging pump for a nuclear power plant of the present invention;

2 is a schematic structural view of a stator component of an upper charging pump for a nuclear power plant of the present invention;

3 is a schematic structural view of an inner casing of an upper charging pump for a nuclear power plant of the present invention;

4 is a schematic structural view of a unit fluid guiding member in a stator component of a charging pump for a nuclear power plant according to the present invention; and FIG. 5 is a schematic structural view of a pump head in a stator component of a charging pump for a nuclear power plant according to the present invention.

6 is a schematic structural view of a rotor component of a charging pump for a nuclear power plant of the present invention;

7a, 7b, and 7c are schematic structural views of a first-stage impeller, a two- to four-stage impeller, and five to twelve-stage impellers in a rotor component of a charge pump for a nuclear power plant according to the present invention;

8 is a schematic structural view of a driving end bearing of an upper charging pump for a nuclear power plant of the present invention;

9 is a schematic structural view of an intermediate bearing of a charging pump for a nuclear power plant of the present invention;

Figure 10 is a schematic structural view of a non-drive end bearing of a charge pump for a nuclear power plant of the present invention;

Figure 11 is a schematic view showing the structure of a shaft sealing device for a charge pump for a nuclear power plant of the present invention. detailed description

In order to better understand the technical solution of the present invention, the following detailed description will be made by way of specific examples and with reference to the accompanying drawings:

Please refer to FIG. 1. Referring to FIG. 1, the upper charging pump for a nuclear power plant includes a stator component 1, a rotor component 2, a bearing component, and a shaft sealing device 4. The bearing components include a drive end bearing 31, an intermediate auxiliary bearing 32, and a non-drive end bearing 33.

Referring to Fig. 2, the stator component of the charge pump for a nuclear power plant of the present invention includes a pump head 11, a cylinder body and a tail plate 14 which are sequentially connected in front and rear. The cylinder body includes an outer casing 12 and an inner casing 13 , and a cylinder sliding block 130 is disposed at a position where the cylinder body and the pump base are coupled, so as to ensure that the charging pump is disassembled and installed with high resettability; meanwhile, in an accident working condition, the stator is made The component can withstand the axial extension of the thermal expansion, does not affect the centering of the pump and the center of the speed increaser, and ensures the operability and stability of the pump set; the outer casing 13 is fixed to the rear end surface of the pump head 11, the outer casing The inner cavity of the body 13 includes a majority of the inner housing cavity in the front and a rear bearing cavity in the rear small portion.

Referring to FIG. 3 again, the inner casing 12 is a radially split structure and includes a first plate 121 and a pump head side flow guide which are sequentially connected. Body 122, intermediate section 123, cylinder side fluid guide 124, tail cap 125, rear bearing cap 126, and seal ring 1200. Wherein: the rear end surface of the first plate 121 is provided with a semi-spiral vortex chamber arranged symmetrically at 180°;

The pump head side fluid guide 122 is composed of three unit cell fluid guides 120, and a semi-spiral vortex chamber arranged symmetrically at 180° is respectively disposed on the front and rear end faces of each unit cell fluid guide 120;

The front and rear end faces of the intermediate section 123 are respectively provided with a semi-spiral vortex chamber arranged symmetrically at 180°; the cylinder side pilot fluid 124 is composed of seven-section unit fluid guide 120 and is mounted opposite to the pump head side fluid guide 122; a front end surface of the cover 125 is provided with a semi-spiral vortex chamber arranged symmetrically at 180°;

The rear end surface of the first plate 121, the front and rear end faces of each of the unit fluid guiding members 120, the front and rear end faces of the intermediate portion 123, and the front end surface of the tail cover 125 are axially respectively provided with corresponding positioning pin holes and connecting through holes;

The first plate 121, the three-cell fluid guiding body 120 of the pump head side fluid guiding body 122 and the intermediate section 123 pass through the pin 127. The pin hole of the rear end surface of the unit fluid guiding body 120 is opposite to the front end of the unit guiding fluid 120. The pin holes on the surface are radially positioned and axially locked by the tensioning studs 128 and the nuts 129 passing through the connecting through holes, and the three-section unit fluid guiding body 120 and the intermediate section 123 of the pump head side fluid guiding body 122 are axially locked; The middle section 123, the seven-section unit fluid guide 120 of the cylinder side fluid guide 124 and the tail cap 125 pass through the pin hole 127 of the previous section of the unit guide fluid 120 on the rear end surface of the unit. The pin holes on the front end face are radially positioned and axially locked by the intermediate section 123, the seven-section unit fluid guide 120 and the tail cap 125 of the barrel side fluid guide 124 through a tension stud 128 and a nut 129 that pass through the connection through hole. Tight

The first plate 121, the pump head side fluid guide 122, the intermediate section 123, the cylinder side fluid guide 124 and the tail cover 125 are connected to each other to have a complete cavity for accommodating the impeller, which can automatically generate the radial force generated by the impeller during operation. balance.

Referring to FIG. 4, each of the front and rear end faces of the unit fluid guiding body 120 is respectively provided with a semi-helical vortex chambers 1211 and 1211 ′ arranged symmetrically at 180°, so that the connected guiding fluids have a complete accommodating impeller. The cavity of the front vortex chamber 1211 of each unit of the fluid guiding body 120 further defines a suction port 1213, and a discharge port 1214 is defined in the center of the bottom wall of the rear vortex chamber 121. There is also a pressurized water chamber 1212. A corresponding positioning pin hole 1215 and a connecting through hole 1216 are respectively axially opened on the front and rear end faces of each unit of the fluid guiding body 120. The front end surface of each unit guiding fluid 120 is axially opened. Flow path 1217.

The seal ring 1200 is installed on the suction port of each unit of the fluid guide 120 and the wall of the discharge port. Each of the seal rings 1200 is provided with a plurality of labyrinth seal grooves on the inner wall of the seal ring 1200 to prevent wear of the suspended solids by the suspended solids. And destruction.

The positioning structure of the pump head side fluid guide 122 and the cylinder side fluid guide 124 greatly reduces the number of parts required for each section of the fluid guiding connection, and it is convenient to simply loosen the nut of the tension stud 12 during maintenance. Cleaning the fluid guide to make the flow The inspection and assembly of the body is very convenient and simple.

The material of the sealing ring 1200 is martensitic stainless steel, and the difference in hardness between the surfaces of the sealing ring 1200 is more than 50HB by heat treatment, which ensures that there is no contact between the impeller and the fluid guiding body on the rotor component, and the suspended solid can be hidden in the sealing ring when the pump is running. In the labyrinth seal groove, the wear and damage of the suspended solids to the overcurrent components are avoided, thereby ensuring the integrity, operability and stability of the pump under accident conditions.

Referring to FIG. 5 and referring to FIG. 2, the pump head 11 includes a main body portion of the disc structure and an inlet flange 15 and an outlet flange 16 connected to the main body portion. The main body portion is provided with an axial hole 111 and an inlet. Hole 112 and outlet hole 113. Its towel:

The axial hole 111 is opened at the center of the front and rear end faces of the main body portion;

The inlet hole 112 is formed on the outer peripheral surface of the main body portion and is composed of two upper and lower sections. The upper section of the inlet hole is perpendicular to the axial hole 111, the lower section of the inlet hole is formed at an obtuse angle to the upper section of the inlet hole, and the lower opening of the lower section of the inlet hole is located at the main body. The rear end of the department;

The outlet hole 113 is formed on the outer peripheral surface of the main body portion at 180° from the upper portion of the inlet hole and communicates with the axial hole 111. The outer peripheral surface of the main body portion further defines a machine seal flushing hole 114 communicating with the axial hole 111. ;

The inlet flange 15 is welded to the outer peripheral surface of the main body portion coaxially with the inlet hole 112; the outlet flange 16 is welded to the outer peripheral surface of the main body portion coaxially with the outlet hole 112; The welded portion is subjected to flaw detection, and the outer peripheral surface of the main body portion is provided with a boss at a position connected to the inlet flange 15 and the outlet flange 16. During maintenance, the pump can be lifted as a whole by loosening the bolts of the inlet flange 15 and the outlet flange 16.

The pump head 11 is also connected to the pump base, that is, the front end surface of the main body portion is connected with two positioning keys 17, and a pump head chute block 18 is connected to the outer peripheral surface of the main body portion to ensure the positioning and installation of the upper charging pump. Moreover, the pump set is disassembled and installed with high resettability, thereby ensuring the operability and stability of the pump set.

The first plate 121 of the inner casing 12 is fixed to the rear end surface of the pump head 11 such that the front plate 121, the pump head side fluid guide 122, the intermediate section 123, the cylinder side pilot fluid 124, and the front half of the tail cap 125 are located in the outer casing. In the inner casing cavity of the body 13, the rear half of the tail 125 cover and the rear bearing cap 126 are located in the rear bearing cavity of the outer casing 13, and the rear end face of the rear bearing cap 126 and the front end face of the tail plate 14 have a free space.

The pump head 11 and the tail plate 14 are fixed on the cylinder by studs, nuts and washers; the pump head 11 and the cylinder body, and between the cylinder body and the tail plate 14 are sealed by 0-rings.

Referring to FIG. 6 again, the rotor component 2 includes a rotating shaft 20 and an impeller, an intermediate bushing 24 that is sleeved on the rotating shaft 20, The front sleeve 25, the thrust plate 26, the positioning sleeve 27, the rear bearing sleeve 28 and the lock nut 29, wherein the impeller is composed of a twelve-stage impeller including a first-stage impeller 21 and two to four-stage impellers 22 Five to twelve stage impellers 23. The water inlet of the first four-stage impeller points to the driving end of the upper charging pump, and the rear eight-stage impeller is symmetrically arranged back-to-back with the first four-stage impeller;

The twelve-stage impeller is mounted on the rotating shaft 20 through the snap ring 201 and the transmission key 202;

The intermediate sleeve 24 is disposed between the fourth stage impeller 22 and the fifth stage impeller 3;

The front bushing 25, the thrust plate 26 and the positioning sleeve 27 are fixed to the rotating shaft 20 by a lock nut 29 and are disposed in front of the first stage impeller 21;

The rear bearing sleeve 28 is fixed to the rotating shaft 20 by a lock nut 29 and is provided at the rear of the tenth second stage impeller 23. Referring to FIG. 7a, FIG. 7b, and FIG. 7c, the first stage impeller 21, the second to fourth stage impellers 22, and the fifth to twelfth stage impellers 23 respectively include hubs 211, 221, 231 front cover plates 212, 222, 232 and a rear cover. Plates 213, 223, 233 and a plurality of blades 214, 224, 234, wherein

The hubs 211, 221, 231 are connected to the rear covers 213, 223, 233, and the plurality of blades 214, 224, 234 are respectively uniformly connected between the front cover plates 212, 222, 232 and the rear cover plates 213, 223, 233;

The front cover plates 212, 222, 232 and the rear cover plates 213, 223, 233 have the same diameter;

The ratio of the inlet diameter D11 of the first stage impeller 21 to the outlet width L1 and the outlet diameter D12 is 11~14: 1: 5. 5~

7. 5;

The ratio of the inlet diameter D21 of the second to fourth stage impeller 22 to the outlet width L2 and the outlet diameter D22 is 18. 5~20. 5: 1: 8. 5~10· 5;

The ratio of the inlet diameter D31 of the fifth to twelve-stage impeller 23 to the outlet width L3 and the outlet diameter D32 is 19. 5~21. 5: 1: 9. 5~11·5;

The length of the hub 211 of the first stage impeller 21 is shorter than the length of the hub 221 of the second to fourth stage impeller 22 and the length of the hub 231 of the fifth to twelve stage impellers 23;

The number of blades 214 of the first stage impeller 21 and the number of blades 224 of the second to fourth stage impeller 22 are five, and the number of blades 234 of the fifth to twelve stage impeller 23 is three.

The parameter design of the impeller structure, due to the hydraulic factor, the inlet diameter, the outlet width and the outlet diameter of the impeller vary according to the hydraulic factors. In order to meet the requirements of the large flow condition, the outlet width of the first stage impeller 21 is appropriately widened. And the first-stage impeller 21 takes into account the anti-cavitation performance requirements of the upper charge pump, and the fifth to twelve-stage impeller 23 takes into account the flow-lift curve steep drop characteristic of the upper charge pump. It can significantly improve the efficiency of the charge pump and reduce energy consumption. Each stage of the impeller is integrally cast, locked by a snap ring 201 and transmitted with a transmission key 202 to prevent loosening during rotation. The inner and outer ends of the keyway and the shoulder are rounded to prevent obvious stress concentration. In addition, the impeller and the rotating shaft adopt a clearance fit to facilitate disassembly and assembly. More importantly, it is convenient for radioactive materials during maintenance. Cleaning. When the keyway is opened on the rotating shaft, the uniformity of the position of the impeller blades is fully considered, and the key grooves are evenly distributed in the range of 360° on the rotating shaft.

The critical speed of the shaft is calculated. The first-order critical speed is more than 25% larger than the maximum speed, which is completely deviated from all predictable excitation frequencies (ie, 50 Hz). Therefore, the shaft is rigid.

Since the structure of the non-drive end of the upper charge pump is closed, the axial force of the pump of this structure is related to the inlet pressure, so the total axial force is caused by the pump inlet pressure acting on the impeller, the middle and the end, respectively. Three-part axial force synthesis caused by the bearing. The combination of the upper pump impeller is a four-stage back-to-back arrangement of the drive end four stages and a non-drive end, and three kinds of impellers of different inlet sizes are skillfully combined. By calculating the direction of the axial resultant force acting on the impeller, it is directed to the driving end, and is received by the thrust bearing of the driving end, thereby avoiding the setting of the balancing mechanism, and the accident that the axial force balancing mechanism is engaged and the rotating shaft is broken.

Referring to FIG. 8 again, the driving end bearing 31 includes an upper bearing cap 311, a lower bearing body 312, front and rear bearing end caps 313, 314, a double-sided thrust bearing 315, a sliding bearing 316, and two oil seal chambers 317. Two floating seals 318 and bearing supports 319, wherein:

The upper bearing cap 311 and the lower bearing body 312 are integrally formed by the front and rear bearing end caps 313 and 314 to form a bearing chamber and accommodate the thrust disc 26;

The double-sided thrust bearing 315 includes two thrust blocks which are respectively disposed in the bearing chamber and located on the front and rear end faces of the thrust plate 26;

The sliding bearing 316 includes a bearing seat and a bearing bush located in the inner cavity of the bearing seat, and the radial sliding bearing 316 is disposed in the bearing chamber and located at the front of the double-sided thrust bearing 6;

Two oil seal chambers 317 are disposed in the bearing chamber and are respectively located at the rear of the double-sided thrust bearing 315 and at the front of the radial sliding bearing 316;

Two floating seals 318 are disposed in the two oil seal chambers 317;

A bearing support 319 is attached to the lower portion of the lower bearing body 312 for supporting the bearing.

The double-sided thrust bearing 315 is used to support the axial force, the sliding bearing 316 is used to bear the radial force, and the oil seal chamber 317 and the floating seal 318 are disposed outside the double-sided thrust bearing 315 and the sliding bearing 316, once the charging pump passes In the initial operation, the lubricating oil is stored between the oil seal chamber 317 and the floating seal 318, so that the pump set is very simple No pre-lubrication is required.

Referring again to Fig. 9, the intermediate auxiliary bearing 32 is a hydrostatic bearing which is composed of a cylinder 321 and a flange 322 connected to the end of the cylinder 321 , wherein:

The middle and the rear of the inner surface of the cylinder 321 respectively define a back sink 323 and a sink 324;

The front portion of the inner surface of the cylinder 321 is circumferentially provided with a plurality of rectangular water chambers 325 to form a circumferential water film, which can make the contact area between the rotating shaft and the bearing small when the pump is stationary, and the friction area of the pump during operation. Small, so that the power consumption is small, the temperature rise is low; a water inlet hole 3250 is radially opened in the center of the bottom surface of each rectangular water chamber 325; each water inlet hole 3250 is a small stepped hole in the outer large inner;

a front end surface of the cylinder 321 and between the two adjacent rectangular water chambers 5 axially opening a plurality of water outlet holes 3230 communicating with the return water tank 3;

The outer surface of the cylinder 321 defines a plurality of inclined holes 3240 communicating with the sealing water tank 324.

Referring to FIG. 10 again, the non-drive end bearing 33 is also a hydrostatic bearing, which has a cylindrical structure, and a central portion of the inner surface of the cylinder is circumferentially provided with a plurality of I-shaped water chambers 331 to form a circumference. The water film makes the contact area between the rotating shaft and the bearing large when the pump is at rest, the anti-vibration performance is good, the water film pressing force is large, the function of the protective rotor is reduced and the wear is reduced; the central diameter of the bottom surface of each I-shaped water chamber 331 A water inlet hole 332 is opened, and the water inlet hole 332 is a first stepped hole which is small inside the outer large.

Referring to FIG. 11, the shaft sealing device 4 is mounted on the rotating shaft 20 and located at the front of the axial hole 111 of the pump head 11 of the upper charging pump. The shaft sealing device 4 includes a machine sleeve 41, a pressure plate 42, and a rotating ring 43. , a stationary ring seat 44, a stationary ring 45, a pressure ring 46, a plurality of springs 47, a throttle bushing 48, a positioning piece 49 and a locking disk 411, wherein:

The machine sleeve bushing 41 includes a sleeve body and a sleeve connected to the rear end of the sleeve body. The front end surface of the sleeve body is provided with a ring groove, and the front outer surface of the sleeve body body is provided with a card slot. The sleeve is fixedly mounted on the rotating shaft 20 by the locking disc 411;

The pressure plate 42 includes a flange and a sleeve connected to the rear end surface of the flange. The front end surface of the flange is provided with a recess, and the inner cavity surface of the sleeve is a stepped surface of the outer high and the inner low, in the sleeve A plurality of blind holes are uniformly disposed on the outer step surface; the pressure plate 42 is sleeved on the sleeve body of the machine sleeve 1 through the radial positioning pin 421, and the sleeve sleeve is sleeved on the machine sleeve 41 The outer surface of the pump head 11 is fixed on the front end surface of the pump head 11; the rear end surface of the flange of the pressure plate 42 further defines a flushing hole 422 communicating with the inner cavity of the sleeve;

The rotating ring 43 is fixed in the ring groove of the machine sleeve bushing 41 to rotate with the rotating shaft 20;

The stationary ring seat 44 is axially movably mounted in the inner cavity of the sleeve of the pressure plate 42 by a radial positioning pin 440; The static ring 45 is mounted on the inner cavity of the sleeve of the pressure plate 42 and fixed on the rear end surface of the stationary ring seat 44; the pressure ring 46 is fitted on the outer end of the stationary ring 45 and fixed on the rear end surface of the stationary ring seat 44;

A plurality of springs 47 are placed in the blind holes of the pressure plate 42, and the rear ends of the plurality of springs 47 are connected to the front end surface of the stationary ring seat 4 such that the rear end surface of the stationary ring 45 is always attached to the front end surface of the rotating ring 43. ;

The throttle bushing 48 is mounted in the recess of the pressure plate 42 by a radial positioning pin 480;

The positioning piece 49 is snapped into the card slot of the machine sleeve bushing 41 so that the pressure plate 42 abuts against the rear end surface of the positioning piece 49. Between the inner cavity surface of the machine bushing 41 and the rotating shaft 20, between the flange rear end surface of the pressure plate 42 and the pump head 11, between the outer surface of the sleeve of the pressure plate 42 and the pump head 11, and inside the sleeve of the pressure plate 42 Between the cavity surface and the stationary ring seat 44, between the outer surface of the rotating ring 43 and the machine bushing 41, between the front end surface of the stationary ring 45 and the stationary ring seat 44, the outer surface of the stationary ring 45 and the pressure ring 46 A 0-shaped seal ring 412 is provided between each.

The working principle of the shaft sealing device 4 is: during the operation of the pump, a medium filled with a certain pressure is formed in the cavity formed by the mechanical sealing chamber of the pump head 11 and the pressure plate 42, and the end surface area of the rotating ring 43 is not pressurized. Then, a pressing force is formed to the stationary ring 45, and the stationary ring 45 is appropriately fitted to the contact surface formed between the rotating ring 43 and the stationary ring 45 by the spring 47, thereby maintaining a very thin layer between the contact faces. Liquid film to achieve the purpose of sealing;

The rear end surface of the flange of the pressure plate 42 further defines a flushing hole 422 communicating with the inner cavity of the sleeve, communicating with the flushing hole 114 opened in the pump head 11, and no external flushing line is provided, and a hydrocyclone is provided. It is used to effectively separate impurities and dirty suspended matter in the medium, so that the clean medium is used for flushing the contact surfaces of the rotating ring 43 and the stationary ring 45 and taking away the heat generated.

In addition, after the failure of the rotating ring 43 and the stationary ring 45, the throttle bushing 48 can effectively reduce the leakage of the mechanical seal and ensure that the maximum leakage is less than the minimum requirement.

It is to be understood by those skilled in the art that the above-described embodiments are only intended to illustrate the invention, and are not intended to limit the invention, as long as it is within the spirit of the invention, Variations and modifications are intended to fall within the scope of the appended claims.

Claims

Claim

A charge pump for a nuclear power plant, comprising a stator component, a rotor component, a bearing component, and a shaft seal device. The stator component includes a pump head, a cylinder body, and a tail plate, and the cylinder body includes an outer casing body and an inner casing. The rotor component includes a rotating shaft and an impeller, an intermediate bushing, a front bushing, a thrust disc, a positioning sleeve and a rear bearing sleeve which are sleeved on the rotating shaft, and the bearing component comprises a driving end bearing, an intermediate auxiliary bearing and a non-driving end bearing, It is characterized in that

The pump head comprises a body portion of a disc structure and having an axial hole, an inlet hole and an outlet hole;

The drive end bearing includes an upper bearing cap, a lower bearing body, front and rear bearing end caps, a double-sided thrust bearing, a sliding bearing, two oil seal chambers and two floating seals, the upper bearing cap and the lower bearing body Connected to the front end surface of the pump head and integrated by the front and rear bearing end covers to form a bearing chamber; the double-sided thrust bearing is disposed in the bearing chamber and located at the front and rear ends of the thrust plate The sliding bearing is disposed in the bearing chamber and located at a front portion of the double-sided thrust bearing; the two oil seal chambers are disposed in the bearing chamber and respectively located at a rear portion of the double-sided thrust bearing and a front portion of the sliding bearing; the two floating seals are disposed one by one in the two oil seal chambers; the intermediate auxiliary bearing is a hydrostatic bearing and is disposed on the fourth stage impeller and the fifth stage Between the impellers, the front portion of the inner surface of the intermediate auxiliary bearing is circumferentially provided with a plurality of rectangular water chambers. The non-driving end bearing is also a hydrostatic bearing and is disposed at a rear portion of the ground 12-stage impeller. The central portion of the inner surface of the non-driving end bearing is circumferentially arranged with a plurality of I-shaped water chambers;

The upper charging pump for a nuclear power plant according to claim 1, wherein an axial hole in the pump head is opened at a center of front and rear end faces of the main body portion, and an inlet hole on the pump head is opened in the main body portion. The outer peripheral surface is composed of upper and lower two communicating sections, the upper section of the inlet opening is perpendicular to the axial hole, the lower section of the inlet opening is at an obtuse angle to the upper section of the inlet opening, and the lower opening of the lower section of the inlet opening Located on the rear end surface of the main body portion; an outlet hole on the pump head is opened at an angle of 180° to the lower portion of the inlet hole on the outer peripheral surface of the main body portion and communicates with the axial hole;

The charge pump for a nuclear power plant according to claim 1, wherein

The rear end surface of the first plate is provided with a semi-spiral vortex chamber arranged symmetrically at 180°;

The pump head side fluid guide is composed of three unit cell flow guides, and a semi-spiral vortex chamber arranged symmetrically at 180° is respectively disposed on the front and rear end faces of each unit cell fluid guide;

a semi-helical vortex chamber arranged symmetrically at 180° is respectively disposed on the front and rear end faces of the intermediate section; the side guiding fluid of the cylinder body is composed of seven-section unit-conducting fluid and is installed opposite to the fluid-conducting side of the pump head;

a front end surface of the tail cover is provided with a semi-spiral vortex chamber arranged symmetrically at 180°;

The rear end surface of the first plate, the front and rear end faces of each unit of the fluid guiding body, the front and rear end faces of the middle section, and the front end surface of the tail cap respectively axially open corresponding positioning pin holes and connecting through holes;

The first plate, the three-section fluid guiding body of the pump head side and the intermediate section pass the pin hole on the rear end surface of the previous section of the unit fluid guiding pin relative to the pin hole of the front side of the unit guiding fluid of the latter section Positioning and axially locking the three-unit fluid guiding body and the intermediate section of the first plate and the pump head side with a tensioning stud and a nut passing through the connecting through hole; the intermediate section and the cylinder side guide The seven-cell fluid guiding fluid and the tail cap of the fluid pass through the pin hole on the rear end surface of the previous unit of the fluid guiding body, and are radially positioned relative to the pin hole on the front end surface of the unit fluid guiding body and pass through a through hole. The tensioning studs and nuts connecting the through holes axially lock the seven-section unit fluid and the tail cap of the intermediate section and the side of the cylinder.

The upper charge pump for a nuclear power plant according to claim 1, wherein the intermediate auxiliary bearing is composed of a cylinder and a flange connected to one end of the cylinder, and a middle portion of the inner surface of the cylinder A water tank and a water tank are respectively arranged in the rear part, and a water inlet hole is radially opened in the center of the bottom surface of each rectangular water chamber, and a plurality of water outlets communicating with the water return tank are axially opened on the front end surface of the cylinder. a hole; the outer surface of the cylinder is connected to the sealing water tank Oblique hole.

The charging pump for a nuclear power plant according to claim 1, wherein a water inlet hole is radially opened in a center of a bottom surface of each of the I-shaped water chambers on the non-driving end bearing.

The charging pump for a nuclear power plant according to claim 1, wherein the shaft sealing device comprises a machine sleeve, a pressure plate, a rotating ring, a stationary ring seat, a static ring, a pressure ring, a plurality of springs and a section Flow bushing,

The machine sleeve includes a sleeve body and a sleeve connected to the rear end of the sleeve body. The front end surface of the sleeve is provided with a ring groove, and the machine sleeve is fixedly mounted on the rotating shaft through the locking disk;

The pressure plate comprises a flange and a sleeve connected to the rear end surface of the flange, the front end surface of the flange is provided with a recess, and the inner cavity surface of the sleeve is a stepped surface of the outer high and the inner low, in the sleeve a plurality of blind holes are uniformly disposed on the outer step surface; the pressure plate is sleeved outside the sleeve body of the machine seal sleeve with a flange gap, and the sleeve gap is sleeved outside the sleeve of the machine seal sleeve The manner is fixed on the front end surface of the pump head;

The rotating ring is fixed in a ring groove of the machine sleeve bushing;

The stationary ring seat is axially movably mounted to a lumen of the sleeve of the pressure plate;

The static ring is mounted on the inner cavity of the sleeve of the pressure plate and fixed on the rear end surface of the static ring seat; the pressure ring is sleeved on the outer end of the static ring and fixed on the static ring seat On the back end;

The plurality of springs are placed one by one in the blind hole of the pressure plate, and the rear ends of the plurality of springs are connected to the front end surface of the static ring seat such that the rear end surface of the static ring is always with the rotating ring Front end fitting;

The throttle bushing is mounted in a recess of the pressure plate.

The upper charge pump for a nuclear power plant according to claim 1, wherein a seal sealing hole communicating with the axial hole is further formed in an outer peripheral surface of the main body portion.

The charging pump for a nuclear power plant according to claim 6, wherein a flushing hole communicating with the inner cavity of the sleeve is further disposed on a rear end surface of the flange of the pressure plate.

The charging pump for a nuclear power plant according to claim 6, wherein the front outer surface of the sleeve body is provided with a card slot, and a positioning piece is inserted in the card slot to make The pressing plate abuts against the rear end surface of the positioning piece.