A vertical seawater lifting pump for nuclear power plants

Abstract

The present invention relates to the technical field of lift pumps, and discloses a vertical seawater lift pump for use in nuclear power plants, comprising a pump pipe, a motor disposed at the bottom of the pump pipe, a water inlet connection port and a water outlet connection port disposed at the bottom and top of the pump pipe, respectively, and a plurality of booster impellers disposed within the pump pipe. The pump also comprises a flow rate adaptively reducing component disposed within the pump pipe; the flow rate adaptively reducing component comprises a one-way valve assembly disposed within the pump pipe, and an expansion assembly disposed at the bottom of the one-way valve assembly. By providing the flow rate adaptively reducing component, the flow rate in the one-way valve region located in the high-pressure zone can be adaptively reduced, thereby reducing the impact force on the one-way valve, reducing the probability of cavitation, and increasing the service life of the lift pump.

Description

Technical Field

[0001] The present invention relates to the technical field of lift pumps, and in particular to a vertical seawater lift pump for a nuclear power plant. Background Art

[0002] In nuclear power plants, vertical seawater lift pumps are core equipment to ensure the safe operation of the nuclear island cooling system. They continuously transport seawater to key locations such as the condenser and waste heat removal system through a vertical multi-stage centrifugal structure. The pump adopts a vertical shaft design, with the drive motor driving the series impellers to rotate at high speed. The seawater is pressurized step by step under the action of centrifugal force to achieve large flow and medium to high head requirements. The vertical structure not only saves space, but also optimizes axial force through balancing holes and symmetrical impeller arrangement, reducing bearing wear and vibration risks. Because nuclear power plants have strict requirements for equipment reliability and leakage prevention, the pump body needs to cope with problems such as high salinity corrosion, sediment wear, and biological adhesion in seawater. Therefore, corrosion-resistant materials such as duplex stainless steel impellers, titanium alloy sleeves or concrete volutes are used, and are equipped with shaft seal-free magnetic drive technology to completely eliminate the risk of seal failure.

[0003] To prevent seawater backflow from damaging the impeller and motor, existing vertical lift pumps often incorporate internal one-way valves to prevent backflow of seawater when the lift pump is stopped. When the seawater lift pump is installed at a height exceeding its maximum allowable suction height, the pressure at the pump inlet decreases. When the pressure drops to the saturated vapor pressure, the seawater vaporizes, generating bubbles and causing cavitation. Because the cross-sectional area of ​​the one-way valve region is often relatively small, the seawater in this region experiences a higher flow rate and greater impact force after being pressurized layer by layer. This excessive impact force can disrupt the flow within the pump's flow path, creating localized low-pressure zones. The pressure in these low-pressure zones may be lower than the saturated vapor pressure, causing water to vaporize and form bubbles, which in turn triggers cavitation. This can corrode and damage components and materials in the one-way valve region, and ultimately the lift pump, reducing its service life. Therefore, there is an urgent need for a vertical lift pump that can adaptively reduce its flow rate based on the impact force of the seawater in the one-way valve region, thereby reducing the likelihood of cavitation. Summary of the Invention

[0004] In view of the problem of existing technology that the impact force of seawater in the one-way valve area is too large, which easily causes cavitation and causes corrosion and damage to the pump and parts and materials in the one-way valve area, a vertical seawater lifting pump for nuclear power plants is proposed.

[0005] Its purpose is: by setting up a flow rate adaptive reduction component, the flow rate in the one-way valve area located in the high-pressure area can be adaptively reduced, thereby reducing its impact force on the one-way valve, reducing the probability of cavitation, and increasing the service life of the lift pump.

[0006] The technical solution of the present invention is a vertical seawater lifting pump for a nuclear power plant, comprising a pump pipe, a motor disposed at the bottom of the pump pipe, a water inlet connection port and a water outlet connection port disposed at the bottom and top of the pump pipe respectively, and a plurality of booster impellers disposed within the pump pipe, and further comprising a flow rate adaptive reduction component disposed within the pump pipe;

[0007] The flow rate adaptive reduction component includes a one-way valve component arranged inside the pump tube, and an expansion component arranged at the bottom of the one-way valve component;

[0008] The one-way valve assembly is used to prevent seawater from flowing back and causing damage to the booster impeller and motor; the one-way valve assembly includes a baffle arranged inside the pump pipe, and the expansion assembly includes an expansion groove opened on the inner wall of the pump pipe, a plurality of expansion plates arranged in the expansion groove, a connecting rod arranged on one side of the expansion plate, and an expansion rod arranged on one side of the connecting rod, and the top of the expansion rod passes through the baffle and is fixedly connected to the one-way valve assembly.

[0009] Using the above technical solution, when the seawater lifting pump is in operation, the water inlet and outlet are connected via pipes. The water inlet is placed in seawater, and the motor is started, which drives the internal, vertically evenly distributed, multi-layer booster impellers. After the layers of boosting are completed, the seawater pushes open the one-way valve assembly, allowing the pressurized seawater to flow out of the water outlet, achieving the seawater lifting effect. When the pump speed is too high, it affects the water flow and pressure distribution within the pump, which may lead to cavitation. Excessive water flow force can cause the flow in the pump channel to become turbulent, creating localized low-pressure areas. The pressure in these low-pressure areas may be lower than the saturated vapor pressure, causing water to vaporize in these areas, forming bubbles, which in turn trigger cavitation. Furthermore, excessive water flow force may cause vibrations in the pump components, further destabilizing the water flow, increasing the likelihood of cavitation, and causing corrosion to components in the one-way valve area and surface damage. Therefore, by setting up a flow rate adaptive reduction component, the flow rate in the one-way valve area located in the high-pressure area can be adaptively reduced, thereby reducing its impact force on the one-way valve, reducing the probability of cavitation, and increasing the service life of the lift pump. When the water flow rate is too high, the greater its impact force, the greater the impact on the one-way valve assembly, causing the one-way valve assembly to open more widely. At this time, the one-way valve assembly will simultaneously drive the expansion assembly to expand during the opening process, causing the expansion plate and the connecting rod to expand synchronously under the drive of the expansion rod, thereby increasing the average cross-sectional area of ​​water flow in the bottom area of ​​the baffle, thereby reducing the water flow velocity in this area and reducing the impact force on the one-way valve assembly, thereby reducing the probability of cavitation.

[0010] Furthermore, the expansion assembly also includes a vertical hole opened at the top of the expansion rod, an oblique hole opened on one side of the vertical hole, a sliding hole opened in the middle of the expansion rod, and the connecting rod slides in the vertical hole and the oblique hole through cylindrical limiters symmetrically arranged on both sides, a hinge seat arranged at the bottom of two adjacent expansion plates, and the hinge seat is fixedly connected to the expansion groove, a rotating groove opened at the bottom of the baffle, and a movable groove opened on one side of the expansion groove.

[0011] By adopting the above technical solution, when the one-way valve assembly is pushed open by the water flow, the expansion rod will be driven upward synchronously, so that the connecting rod slides in the vertical hole through the cylinder. At this time, several expansion plates do not rotate. When the impact force of the water flow reaches the threshold, the one-way valve assembly is continuously pushed up, so that the connecting rod moves to the inclined hole. Under the guidance of the inclined hole, the expansion plate is driven to rotate and open, so that the water flow cross-sectional area in the bottom area of ​​the baffle gradually increases and its flow rate is reduced. The setting of the rotating groove is used to facilitate the rotation of the expansion plate, and the setting of the movable groove facilitates the up and down movement of the expansion rod.

[0012] Furthermore, in the initial state, the plurality of expansion plates form a frustum with a narrow top and a wide bottom.

[0013] By adopting the above technical solution, the frustum-shaped expansion plate can guide the water flow, so that the water can quickly flow out from the middle of the one-way valve assembly.

[0014] Furthermore, an oblique groove having the same inclination direction as the oblique hole is provided on the baffle.

[0015] By adopting the above technical solution, when the expansion rod continues to move upward, the greater the impact force of the water flow, the greater the expansion range of the expansion plates, and the better the effect of reducing the speed of the water flow in the reverse direction. When the connecting rod reaches the end of the expansion rod, the bottom side of the expansion rod is in contact with the inclined groove, and the expansion range of the expansion plates is also the largest, so that the expansion plates are in a vertical state. At this time, the average cross-sectional area through which the water flows is the largest, and the effect of reducing the speed of the water flow is also the largest.

[0016] Furthermore, the bottom of the expansion rod moves in the movable groove, and the end of the expansion rod is located on one side of the hinged rotation point of the bottom of the expansion plate in the vertical direction.

[0017] By adopting the above technical solution, the expansion rod moves in the movable groove so that the end of the expansion rod is located on the left side of the bottom of the expansion plate in the vertical direction. This makes it convenient for the expansion plate to be in a vertical state when the connecting rod moves to the end of the expansion rod, thereby forming the maximum cross-sectional area for water flow and improving the deceleration effect on the water flow.

[0018] Furthermore, the one-way valve assembly includes a valve plate arranged on the top of the baffle, a valve column arranged on the top of the valve plate, a spring sleeved on the valve column, and an abutment column arranged on the top of the spring, and the valve column slides within the abutment column, and the bottom of the valve plate is fixedly connected to a number of expansion rods evenly distributed and passing through the baffle.

[0019] With the above technical solution, when the valve plate is lifted up, water flows out from between the valve plate and the baffle, and the spring is compressed, causing the valve column to slide upward in the ground connection column. When the lift pump stops running, the valve plate blocks the baffle under the resetting action of the spring, preventing the backflow of water from causing damage to the booster impeller and motor.

[0020] Furthermore, an arcuate groove is provided on the top of the rotating groove, and spikes are evenly and annularly distributed on the arcuate groove.

[0021] With the above technical solution, when the expansion plate is unfolded, the arc-surface groove is exposed. At this time, part of the water flow will flow out from the middle, and the other part will enter the arc-surface groove. The part of the water flow entering the arc-surface groove will circulate back along the inclined surface of the arc-surface groove under the action of the impact force. After entering the arc-surface groove, the bubbles generated in the high-pressure area are punctured, further reducing the probability of cavitation.

[0022] Furthermore, the spike is inclined in the same direction as the arc groove.

[0023] By adopting the above technical solution, since the water flows back and forth along the arc-surface groove, the sharp thorns can better puncture the bubbles, thereby enhancing the bubble removal effect.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. By setting up the flow rate adaptive reduction component, the flow rate in the one-way valve area located in the high-pressure area can be adaptively reduced, thereby reducing the impact force on the one-way valve, reducing the probability of cavitation, and increasing the service life of the lift pump.

[0026] 2. When the valve plate is lifted up, water flows out from between the valve plate and the baffle, and the spring is compressed, causing the valve column to slide upward in the ground connection column. When the lift pump stops running, the valve plate blocks the baffle under the reset action of the spring to prevent the backflow of water from damaging the booster impeller and motor.

[0027] 3. When the expansion plate is unfolded, the arc groove is exposed. At this time, part of the water flow will flow out from the middle, and the other part will enter the arc groove. Under the action of the impact force, the part of the water flow entering the arc groove will circulate back along the inclined surface of the arc groove. After entering the arc groove, the bubbles generated in the high-pressure area are punctured, further reducing the probability of cavitation. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the overall three-dimensional structure of the seawater lifting pump of the present invention;

[0029] Figure 2 It is a schematic diagram of the three-dimensional structure inside the end of the seawater lifting pump of the present invention;

[0030] Figure 3 This is a schematic diagram of the exploded structure of the internal structure of the pump body at the end of the lift pump of the present invention;

[0031] Figure 4 This is a schematic diagram of the overall front cross-sectional structure of the pump body of the present invention;

[0032] Figure 5 For the present invention Figure 4 A magnification of point A in the middle and a schematic diagram of the water flow direction structure;

[0033] Figure 6 Schematic diagram of the exploded structure of the one-way valve assembly and the expansion assembly of the present invention;

[0034] Figure 7 This is a schematic diagram of the coordinated three-dimensional structure of the expansion rod, expansion plate and connecting rod of the present invention in their initial state;

[0035] Figure 8 It is an enlarged diagram of the baffle of the present invention and a schematic diagram of the seawater return circulation direction structure.

[0036] In the figure: 1. Pump pipe; 2. Motor; 3. Water inlet connection port; 4. Water outlet connection port; 5. One-way valve assembly; 51. Baffle; 52. Valve plate; 53. Valve column; 54. Spring; 55. Abutment column; 6. Expansion assembly; 61. Expansion groove; 62. Expansion plate; 63. Connecting rod; 64. Expansion rod; 65. Vertical hole; 66. Oblique hole; 67. Sliding hole; 68. Articulated seat; 69. Rotating groove; 70. Moving groove; 71. Oblique groove; 8. Arc groove; 9. Spike. DETAILED DESCRIPTION

[0037] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0038] Example 1, with reference to Figures 1-8, which is a first embodiment of the present invention, provides a vertical seawater lifting pump for a nuclear power plant, comprising a pump pipe 1, a motor 2 mounted at the bottom of the pump pipe 1, a water inlet connection port 3 and a water outlet connection port 4 mounted at the bottom and top of the pump pipe 1 respectively, and a plurality of booster impellers mounted inside the pump pipe 1, and also comprising a flow rate adaptive reduction component mounted inside the pump pipe 1; the flow rate adaptive reduction component comprises a one-way valve assembly 5 mounted inside the pump pipe 1, and an expansion assembly 6 mounted at the bottom of the one-way valve assembly 5; the one-way valve assembly 5 is used to prevent seawater from flowing back and damaging the booster impeller and the motor 2; the one-way valve assembly 5 comprises a baffle 51 fixedly connected to the inside of the pump pipe 1, the expansion assembly 6 comprises an expansion groove 61 formed on the inner wall of the pump pipe 1, a plurality of expansion plates 62 rotatably connected to the expansion groove 61, a connecting rod 63 fixedly connected to one side of the expansion plate 62, and an expansion rod 64 slidably connected to one side of the connecting rod 63, with the top of the expansion rod 64 passing through the baffle 51 and fixedly connected to the one-way valve assembly 5.

[0039] Specifically, when the seawater lift pump is operating, it connects the water inlet connection 3 and the water outlet connection 4 via pipes. The pipes are then placed in seawater, and the motor 2 is started, which drives the rotation of several vertically evenly distributed multi-layer booster impellers inside (this is prior art and will not be described in detail). After the seawater is pressurized layer by layer, it pushes open the one-way valve assembly 5, allowing the pressurized seawater to flow out of the water outlet connection 4, thereby lifting the seawater. When the pump speed is too high, it will affect the water flow and pressure distribution within the pump, which may lead to cavitation. Excessive water flow impact can cause the flow state in the pump channel to become turbulent, creating localized low-pressure areas. The pressure in these low-pressure areas may be lower than the saturated vapor pressure, causing water to vaporize in these areas to form bubbles, which in turn triggers cavitation. Furthermore, excessive water flow impact can cause vibrations in the pump components, further disrupting the stability of the water flow, increasing the likelihood of cavitation, and causing corrosion to components in the one-way valve area within the pump, as well as damage to the material surface. Therefore, by setting up a flow rate adaptive reduction component, the flow rate in the one-way valve area located in the high-pressure area can be adaptively reduced, thereby reducing its impact force on the one-way valve, reducing the probability of cavitation, and increasing the service life of the lift pump. When the water flow rate is too high, the greater its impact force, the greater the impact on the one-way valve assembly 5, causing the one-way valve assembly 5 to open more widely. At this time, the one-way valve assembly 5 will simultaneously drive the expansion assembly 6 to expand during the opening process, causing the expansion plate 62 and the connecting rod 63 to expand synchronously under the driving action of the expansion rod 64, thereby increasing the average cross-sectional area of ​​the water flow in the bottom area of ​​the baffle 51, thereby reducing the water flow velocity in this area and reducing the impact force on the one-way valve assembly 5, thereby reducing the probability of cavitation.

[0040] Reference Figure 2-Figure 7The expansion assembly 6 also includes a vertical hole 65 opened at the top of the expansion rod 64, an oblique hole 66 opened on one side of the vertical hole 65, and a sliding hole 67 opened in the middle of the expansion rod 64. The connecting rod 63 slides in the vertical hole 65 and the oblique hole 66 through the cylindrical limiters symmetrically arranged on both sides, and is rotatably connected to the hinge seat 68 at the bottom of the two adjacent expansion plates 62. The hinge seat 68 is fixedly connected to the expansion slot 61, a rotating slot 69 opened at the bottom of the baffle 51, and a movable slot 70 opened on one side of the expansion slot 61.

[0041] Specifically, when the one-way valve assembly 5 is pushed open by the water flow, it will simultaneously drive the expansion rod 64 to move upward, so that the connecting rod 63 slides in the vertical hole 65 through the cylinder. At this time, several expansion plates 62 do not rotate. When the impact force of the water flow reaches the threshold, the one-way valve assembly 5 is continuously pushed up, so that the connecting rod 63 moves to the inclined hole 66. Under the guidance of the inclined hole 66, the expansion plate 62 is driven to rotate and open, so that the water flow cross-sectional area in the bottom area of ​​the baffle 51 gradually increases, reducing its flow rate. The setting of the rotating groove 69 is used to facilitate the rotation of the expansion plate 62, and the setting of the moving groove 70 facilitates the up and down movement of the expansion rod 64.

[0042] Reference Figure 6-Figure 7 In the initial state, a plurality of expansion plates 62 form a truncated cone with a narrow top and a wide bottom.

[0043] Specifically, the frustum-shaped expansion plate 62 can guide the water flow, so that the water can quickly flow out from the middle of the one-way valve assembly 5 .

[0044] Reference Figure 5 A slanted groove 71 having the same slant direction as the slanted hole 66 is further provided on the baffle 51 .

[0045] Specifically, when the expansion rod 64 continues to move upward, the greater the impact force of the water flow, the greater the expansion range of the expansion plates 62, and the better the effect of reducing the speed of the water flow in the opposite direction. When the connecting rod 63 reaches the end of the expansion rod 64, the bottom side of the expansion rod 64 is in contact with the inclined groove 71, and the expansion range of the expansion plate 62 is also the largest, so that the expansion plates 62 are in a vertical state. At this time, the average cross-sectional area of ​​the water flow is the largest, and the effect of reducing the speed of the water flow is also the largest.

[0046] Reference Figure 5 The bottom of the expansion rod 64 moves in the movable groove 70 , and the end of the expansion rod 64 is located on one side of the hinged rotation point at the bottom of the expansion plate 62 in the vertical direction.

[0047] Specifically, the expansion rod 64 moves in the movable groove 70 so that the end of the expansion rod 64 is located on the left side of the bottom of the expansion plate 62 in the vertical direction, so that when the connecting rod 63 moves to the end of the expansion rod 64, the expansion plate 62 can be in a vertical state, thereby forming the maximum cross-sectional area for water flow to pass through, thereby improving the deceleration effect on the water flow.

[0048] Example 2, reference Figure 4-Figure 7 , which is the second embodiment of the present invention. This embodiment is different from the first embodiment in that: the one-way valve assembly 5 includes a valve plate 52 abutting the top of the baffle 51, a valve column 53 fixedly connected to the top of the valve plate 52, a spring 54 sleeved on the valve column 53, and an abutting column 55 fixedly connected to the top of the spring 54, and the valve column 53 is limitedly slid in the abutting column 55, and the bottom of the valve plate 52 is fixedly connected to a plurality of expansion rods 64 evenly distributed and passing through the baffle 51.

[0049] Specifically, when the valve plate 52 is lifted, water flows out from between the valve plate 52 and the baffle 51, and the spring 54 is compressed, causing the valve post 53 to slide upward within the ground post. When the lift pump stops running, the spring 54 returns to its original position, causing the valve plate 52 to block the baffle 51, preventing backflow of water and damage to the booster impeller and motor 2. The remaining structure is the same as that of Example 1.

[0050] Example 3, reference Figure 8 , which is the third embodiment of the present invention. This embodiment is different from the second embodiment in that an arcuate groove 8 is provided on the top of the rotating groove 69, and spikes 9 are evenly and annularly distributed on the arcuate groove 8.

[0051] Specifically, when the expansion plate 62 is unfolded, the arc-surface groove 8 is exposed. At this time, part of the water flow will flow out from the middle, and the other part will enter the arc-surface groove 8. The part of the water flow entering the arc-surface groove 8 will circulate back along the inclined surface of the arc-surface groove 8 under the action of the impact force. After entering the arc-surface groove 8, the bubbles generated in the high-pressure area will be punctured, further reducing the probability of cavitation.

[0052] Reference Figure 8 The spike 9 is inclined in the same direction as the arc groove 8.

[0053] Specifically, since the water flows back along the arc groove 8, the spikes 9 can better puncture the bubbles, thereby enhancing the bubble removal effect. The rest of the structure is the same as that of embodiment 2.

[0054] In summary, the working principle of the present invention is as follows: When the seawater lifting pump is in operation, the water inlet connection port 3 and the water outlet connection port 4 are connected via pipes. After the water inlet connection port 3 is placed in seawater, the motor 2 is started, which drives the rotation of several vertically evenly distributed multi-layer booster impellers inside. After the layers of boosting, the seawater pushes open the one-way valve assembly 5, allowing the pressurized seawater to flow out of the water outlet connection port 4, achieving the seawater lifting. When the pump speed is too high, it will affect the water flow state and pressure distribution within the pump, which may lead to cavitation. Excessive water flow impact force can cause the flow state of the flow channel within the pump to become turbulent, creating local low-pressure areas. The pressure in these low-pressure areas may be lower than the saturated vapor pressure, causing water to vaporize in these areas to form bubbles, which in turn triggers cavitation. In addition, excessive water flow impact force may cause vibration of components within the pump, further disrupting the stability of the water flow, increasing the possibility of cavitation, and causing corrosion to parts in the one-way valve area within the pump and damage to the material surface. Therefore, by setting up a flow rate adaptive reduction component, the flow rate in the one-way valve area located in the high-pressure area can be adaptively reduced, thereby reducing its impact force on the one-way valve, reducing the probability of cavitation, and increasing the service life of the lift pump. When the water flow rate is too high, the greater its impact force, the greater the impact on the one-way valve assembly 5, causing the one-way valve assembly 5 to open more widely. At this time, the one-way valve assembly 5 will simultaneously drive the expansion assembly 6 to expand during the opening process, causing the expansion plate 62 and the connecting rod 63 to expand synchronously under the driving action of the expansion rod 64, thereby increasing the average cross-sectional area of ​​the water flow in the bottom area of ​​the baffle 51, thereby reducing the water flow velocity in this area and reducing the impact force on the one-way valve assembly 5, thereby reducing the probability of cavitation.

[0055] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A vertical seawater lift pump for a nuclear power plant, comprising a pump pipe, a motor disposed at the bottom of the pump pipe, a water inlet connection port and a water outlet connection port disposed at the bottom and top of the pump pipe, respectively, and a plurality of booster impellers disposed within the pump pipe, characterized in that: Also included is a flow rate adaptive reduction component disposed inside the pump tube; The flow rate adaptive reduction component includes a one-way valve component arranged inside the pump tube, and an expansion component arranged at the bottom of the one-way valve component; The one-way valve assembly is used to prevent seawater from flowing back and damaging the booster impeller and motor. The one-way valve assembly includes a baffle disposed inside the pump pipe, and the expansion assembly includes an expansion groove formed on the inner wall of the pump pipe, a plurality of expansion plates disposed in the expansion groove, a connecting rod disposed on one side of the expansion plate, and an expansion rod disposed on one side of the connecting rod, wherein the top of the expansion rod passes through the baffle and is fixedly connected to the one-way valve assembly. The expansion assembly also includes a vertical hole opened at the top of the expansion rod, an oblique hole opened on one side of the vertical hole, a sliding hole opened in the middle of the expansion rod, and the connecting rod slides in the vertical hole and the oblique hole through cylindrical limiters symmetrically arranged on both sides, a hinge seat set at the bottom of two adjacent expansion plates, and the hinge seat is fixedly connected to the expansion slot, a rotating slot opened at the bottom of the baffle, and a movable slot opened on one side of the expansion slot; In the initial state, the plurality of expansion plates form a truncated cone shape with a narrow top and a wide bottom.

2. The vertical seawater lift pump for a nuclear power plant according to claim 1, characterized in that: An oblique groove having the same inclination direction as the oblique hole is also provided on the baffle.

3. The vertical seawater lift pump for a nuclear power plant according to claim 1, characterized in that: The bottom of the expansion rod moves in the moving groove, and the end of the expansion rod is located on one side of the hinged rotation point of the bottom of the expansion plate in the vertical direction.

4. The vertical seawater lift pump for a nuclear power plant according to claim 1, characterized in that: The one-way valve assembly includes a valve plate arranged on the top of the baffle, a valve column arranged on the top of the valve plate, a spring sleeved on the valve column, and an abutment column arranged on the top of the spring, and the valve column slides within the abutment column within a limited position, and the bottom of the valve plate is fixedly connected to a number of expansion rods evenly distributed and passing through the baffle.

5. The vertical seawater lift pump for a nuclear power plant according to claim 1, characterized in that: The top of the rotating groove is provided with an arc surface groove, and spikes are evenly and annularly distributed on the arc surface groove.

6. The vertical seawater lift pump for a nuclear power plant according to claim 5, characterized in that: The spike is inclined in the same direction as the arc surface groove.

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