A suction device and method for foreign matter in the bottom of a pressure vessel

Abstract

The application belongs to the technical field of nuclear power plant operation and maintenance, and particularly relates to a suction device and method for foreign matters at the bottom of a pressure vessel. The device comprises a pumping assembly, a suction pipe and a filtering assembly. The pumping assembly and the filtering assembly are connected through the suction pipe. The diameters of the pumping assembly, the suction pipe and the filtering assembly are all smaller than the water flow holes on the lower grid plate of the pressure vessel, so that the device can be inserted into the area at the bottom of the reactor pressure vessel through the water flow holes for operation. The pumping assembly is used for providing suction force for water pumping, and comprises a power motor, an impeller and an impeller cover. The power motor is used for driving the impeller to rotate, and the center of the impeller is a hollow area. The impeller cover is arranged on the outer side of the impeller and is provided with a water outlet hole. The filtering assembly is used for containing the suctioned foreign matters. The device can pass through the water flow holes of the lower core grid plate and directly enter the bottom of the core for operation, and the suction extension pipe is not needed, and the filtering assembly can be quickly removed.

Description

Technical Field

[0001] This application belongs to the field of nuclear power plant operation and maintenance technology, specifically relating to a suction device and method for foreign objects at the bottom of a pressure vessel. Background Technology

[0002] During nuclear power plant operation, foreign objects inside the reactor pressure vessel, such as damaged fuel assembly grid fragments, loose bolts and nuts, can potentially damage the fuel assemblies and thus affect the safe operation of the nuclear power plant. Therefore, foreign object removal must be performed inside the pressure vessel before the fuel assemblies are reloaded into the reactor core.

[0003] When dealing with foreign objects below the lower grid plate of the pressure vessel core, the foreign object disposal tool needs to pass through the drainage holes of the lower grid plate of the pressure vessel core for suction operation. The diameter of the drainage holes is usually less than φ70mm.

[0004] Currently, the existing technology uses a suction method to remove foreign objects from the bottom of the reactor pressure vessel. Existing foreign object suction tools require the suction tool to be placed above the grid plate, and then the suction tube of the suction tool is inserted separately through the lower grid plate to suck up the foreign object. The space below the lower grid plate is large, and the required suction tube is sometimes as long as 3 meters. In addition, the existing foreign object suction tools are heavy, and the operators need to spend a lot of effort to complete the alignment and suction of the foreign object, which is labor-intensive and inefficient. Summary of the Invention

[0005] The purpose of this application is to provide a suction device and method for foreign objects at the bottom of pressure vessels, which solves the problems of existing foreign object suction tools being heavy, requiring operators to expend a lot of effort to align and suction the foreign objects, resulting in high labor intensity and low efficiency.

[0006] The technical solution to achieve the purpose of this application is as follows: The first aspect of this application provides a suction device for foreign matter at the bottom of a pressure vessel, the device comprising: a pump suction assembly, a suction pipe, and a filter assembly; The pump suction assembly and the filter assembly are connected by a suction pipe. The diameters of the pump suction assembly, the suction pipe and the filter assembly are all smaller than the water flow holes on the lower grid plate of the pressure vessel, which are used to extend into the area at the bottom of the reactor pressure vessel through the water flow holes for operation. The pump assembly is used to provide suction for pumping water and includes a power motor, an impeller, and an impeller cover; the power motor drives the impeller to rotate, and the center of the impeller is a hollow area; the impeller cover is located on the outside of the impeller and has an open outlet hole; the filter assembly is used to collect the foreign objects being pumped.

[0007] Optional, the impeller includes: a base plate and multiple blades; Multiple blades are evenly distributed on the base plate, and a hollow area is formed in the middle of the multiple blades.

[0008] Optionally, there are at least two blades.

[0009] Optional, the impeller cover includes: a connecting column, a connecting nozzle, a top plate, and a bottom ring; A water inlet is provided on the top plate, which is connected to the suction pipe via a nozzle; The bottom ring is fixedly connected to the power motor, and the top plate and the bottom ring are fixedly connected by multiple connecting columns. The impeller is set between the top plate and the bottom ring; a water outlet is formed between two adjacent connecting columns.

[0010] Optional, the filter assembly includes: a filter assembly housing and a filter element; The filter assembly housing is connected to the suction tube; the filter element is installed inside the filter assembly housing and is used to hold the suctioned foreign objects.

[0011] Optional, filter elements include: filter screen and suction nozzle; The suction nozzle is located at the front end of the filter assembly housing and is open to the outside. The filter screen is located at the rear of the suction nozzle and contains the foreign objects being suctioned.

[0012] Optionally, a one-way valve is provided between the filter and the suction nozzle.

[0013] Optionally, the power motor can be a pneumatic motor or an electric motor; the suction tube is flexible.

[0014] Optionally, the device may further include: a long-handled tool; The long-hand tool is connected to the pump suction assembly for extending the pump suction assembly, suction pipe, and filter assembly into the area through the water flow hole for operation, and for pulling the pump suction assembly, suction pipe, and filter assembly out of the area for operation.

[0015] The second aspect of this application provides a method for suctioning foreign objects from the bottom of a pressure vessel, applicable to any one of the suction devices for suctioning foreign objects from the bottom of a pressure vessel provided in the first aspect of this application; the method includes: The device is inserted through the water flow hole into the area at the bottom of the reactor pressure vessel for operation. Adjust the orientation of the device so that the filter assembly is pointing towards the foreign object; The motor is started to drive the impeller to rotate. The hollow area in the middle of the impeller creates a negative pressure to pump water. The water is thrown out from the outlet hole, and at the same time, the foreign objects are sucked into the filter assembly.

[0016] The beneficial technical effects of this application are as follows: This application provides a suction device and method for foreign matter removal from the bottom of a pressure vessel. The device includes a pump assembly, a suction pipe, and a filter assembly. The pump assembly and the filter assembly are connected by the suction pipe. The diameters of the pump assembly, suction pipe, and filter assembly are all smaller than the water flow holes on the lower grid plate of the pressure vessel, allowing them to reach into the area at the bottom of the reactor pressure vessel through the water flow holes. The pump assembly provides suction for pumping water and includes a power motor, an impeller, and an impeller cover. The power motor drives the impeller to rotate, and the center of the impeller is a hollow area. The impeller cover is located on the outside of the impeller and has an open water outlet. The filter assembly holds the foreign matter to be suctioned. This application embodiment can bypass the water flow holes on the lower grid plate of the reactor core and directly enter the bottom of the reactor core for operation without the need for a suction extension pipe. Therefore, the suction pipe is shorter, and the operation and positioning are more convenient. Furthermore, the filter assembly is located at the end of the suction pipe, allowing for quick removal when suctioning high-level radioactive materials. Attached Figure Description

[0017] Figure 1 A schematic diagram of a suction device for foreign matter at the bottom of a pressure vessel, provided in an embodiment of this application; Figure 2 This application provides a schematic diagram of the pump suction assembly in a suction device for removing foreign matter from the bottom of a pressure vessel. Figure 3 A schematic diagram of the impeller in a suction device for foreign objects at the bottom of a pressure vessel, provided in an embodiment of this application; Figure 4 A schematic diagram of the component composition of a suction device for foreign matter at the bottom of a pressure vessel, provided in an embodiment of this application; Figure 5 This is a schematic diagram illustrating the application of a suction device for foreign objects at the bottom of a pressure vessel, provided in an embodiment of this application.

[0018] In the picture: 100-Pump suction assembly, 110-Power motor, 120-Impeller, 121-Blade, 122-Base plate, 130-Impeller cover, 131-Outlet, 132-Connecting nozzle, 133-Outlet, 134-Top plate, 135-Bottom ring; 200-Suction tube; 300-Filter assembly, 310-Filter assembly housing, 320-Filter element, 321-Filter screen, 322-Suction nozzle, 323-One-way valve; 400-Long Pole Tools; 500 - Pressure vessel, 501 - Lower grid plate. Detailed Implementation

[0019] To enable those skilled in the art to better understand this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only a part of the embodiments of this application, and not all of them. Based on the embodiments described in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] The inventors of this application discovered in their research that the technical problem with the prior art is that the foreign object suction tools currently used in power plants refer to the principle and structure of conventional water pumps and have a centrifugal pump volute that increases the pumping head. This structure increases the diameter of the suction tool and increases the drainage resistance.

[0021] This application addresses the aforementioned problems by proposing an underwater suction device and method employing an open-type centrifugal approach. This suction device eliminates the centrifugal pump casing used in conventional water pumps to increase pumping head, and features an open impeller casing, resulting in smoother impeller drainage. It boasts a simple structure, lightweight design, and greater suction power. The pump body can pass entirely through the lower grid plate into the bottom area of ​​the pressure vessel, thus significantly shortening the suction pipe. This underwater suction device is convenient to use, facilitates foreign object location, and offers high disposal efficiency, significantly reducing the labor intensity of operators and saving on overhaul time.

[0022] Based on the above, in order to clearly and in detail illustrate the advantages of this application, the specific embodiments of this application will be described below in conjunction with the accompanying drawings.

[0023] See Figure 1 The figure is a schematic diagram of a suction device for foreign objects at the bottom of a pressure vessel provided in an embodiment of this application.

[0024] This application provides a suction device for foreign objects at the bottom of a pressure vessel, comprising: a pump suction assembly 100, a suction pipe 200, and a filter assembly 300; The pump suction assembly 100 and the filter assembly 300 are connected by a suction pipe 200. The diameters of the pump suction assembly 100, the suction pipe 200, and the filter assembly 300 are all smaller than the water flow holes on the lower grid plate 501 of the pressure vessel 500, for operation through which they extend into the area at the bottom of the reactor pressure vessel 500. Figure 5 As shown; The pump suction assembly 100, used to provide suction for pumping water, includes a power motor 110, an impeller 120, and an impeller shroud 130, such as... Figure 2 As shown; the power motor 110 is used to drive the impeller 120 to rotate, and the center of the impeller 120 is a hollow area; the impeller cover 130 is located on the outside of the impeller 120 and has an open water outlet 133; the filter assembly 300 is used to hold the sucked-up foreign objects.

[0025] It is understandable that the impeller 120 generates centrifugal force when rotating, throwing the liquid out, thereby creating a negative pressure in the hollow area in the middle of the impeller 120 for pumping water. In specific implementation, the area of ​​the water outlet 133 can be maximized. The suction device provided in this application embodiment eliminates the centrifugal pump volute used to increase the pumping head, has a small diameter, simple structure, light weight, and low water resistance, significantly increasing the suction load and suction flow rate. It can pass through the water flow holes of the lower grid plate 501 of the reactor core and directly enter the bottom of the reactor core for operation without the need for a suction extension pipe. Therefore, the suction pipe 120 is shorter, and the operation and positioning are more convenient. In addition, the filter assembly 300 is located at the end of the suction pipe 120, and the filter assembly 300 can be quickly removed when pumping high-level radioactive materials.

[0026] As an example, the power motor 110 can be a pneumatic motor or an electric motor; the suction tube 200 is flexible, which facilitates adjustment of the device's position so that the filter assembly 300 is directed toward the foreign object.

[0027] In one example, such as Figure 3 As shown, the impeller 120 includes: a base plate 122 and multiple blades 121; Multiple blades 121 are evenly distributed on the base plate 122, and a hollow area is formed in the middle of the multiple blades 121.

[0028] Understandably, the base plate 122 has a hole in the middle so that the impeller 120 can be installed and fixed.

[0029] In another example, blade 121 can have at least two blades. Figure 3 An example is shown of an impeller 120 structure with five blades 121.

[0030] In some possible implementations of the embodiments of this application, such as Figure 2 As shown, the impeller cover 130 may include: a connecting column 131, a connecting nozzle 132, a top plate 134, and a bottom ring 135; A water inlet hole is provided on the top plate 134, which is connected to the suction pipe 200 through the pipe nozzle 132; The bottom ring 135 is fixedly connected to the power motor 110. The top plate 134 and the bottom ring 135 are fixedly connected by multiple connecting columns 131. The impeller 120 is disposed between the top plate 134 and the bottom ring 135. A water outlet hole 133 is formed between two adjacent connecting columns 131.

[0031] Understandably, the water outlet 133 is evenly arranged around the impeller cover 130, so that the reaction force of the water outlet on the pump body shaft cancels each other out, thus preventing the suction device from tilting or swaying during suction operation.

[0032] In practice, the area of ​​the water outlet 133 can be increased as much as possible while ensuring the strength of the connecting column 131.

[0033] In some possible implementations of the embodiments of this application, such as Figure 4 As shown, the filter assembly 300 may include: a filter assembly housing 310 and a filter element 320; The filter assembly housing 310 is connected to the suction pipe 200; the filter element 320 is installed inside the filter assembly housing 310 and is used to hold the suctioned foreign objects.

[0034] In one example, filter element 320 may include: filter screen 321 and suction nozzle 322; The suction nozzle 322 is located at the front end of the filter assembly housing 310 and is open to the outside. The filter 321 is located on the rear side of the suction nozzle 322 and contains the foreign objects being suctioned.

[0035] In another example, a one-way valve 323 is provided between the filter screen 321 and the suction nozzle 322 to prevent foreign objects from falling out of the filter element 320 when the machine is stopped.

[0036] In some possible implementations of the embodiments of this application, such as Figure 5 As shown, the device may further include: a long-handled tool 400; The long-hand tool 400 is connected to the pump suction assembly 100 and is used to extend the pump suction assembly 100, the suction pipe 200 and the filter assembly 300 into the area through the water flow hole for operation, and to pull the pump suction assembly 100, the suction pipe 200 and the filter assembly 300 out of the area for operation.

[0037] The following is a detailed explanation of the method of using the suction device for foreign objects at the bottom of a pressure vessel provided in this application, with reference to a specific example.

[0038] A typical implementation process includes: Connect the suction device to the long-handled tool 400; The operator uses a long-handled tool 400 to drive the suction device into the reactor core and enters the bottom area of ​​the pressure vessel 500 through the water flow hole of the lower grid plate 501. The operator uses a long-handled tool 400 to adjust the position of the suction device so that the filter assembly 300 is pointing towards the foreign object; Turn on the power switch of the suction device to suck the foreign object into the filter assembly 300; The operator uses a long-handled tool 400 to drive the suction device through the water outlet of the lower grid plate 504 of the pressure vessel 500 and leave the working area at the bottom of the pressure vessel 500. The suction device moves the foreign object to the upper opening of the collection box, shuts off the pump assembly 100, and throws the suctioned foreign object into the collection box.

[0039] The embodiments of this application can bypass the drainage holes of the lower core grid plate and directly enter the bottom of the core for operation without the need for a suction extension pipe. Therefore, the suction pipe is shorter, the operation and positioning are more convenient, and the filter component is located at the end of the suction pipe, so the filter component can be quickly removed when suctioning high-level radioactive materials.

[0040] Based on the suction device for foreign objects at the bottom of a pressure vessel provided in the above embodiments, this application also provides a suction method for foreign objects at the bottom of a pressure vessel, applicable to any one of the suction devices for foreign objects at the bottom of a pressure vessel provided in the above embodiments.

[0041] This application provides a method for suctioning foreign objects from the bottom of a pressure vessel, comprising: The device is inserted through the water flow hole into the area at the bottom of the reactor pressure vessel for operation. Adjust the orientation of the device so that the filter assembly 300 is pointing towards the foreign object; The power motor 110 is started to drive the impeller 120 to rotate. The hollow area in the middle of the impeller 120 forms a negative pressure to pump water. Water is thrown out from the water outlet 133, and at the same time, the foreign object is sucked into the filter assembly 300.

[0042] The embodiments of this application can bypass the drainage holes of the lower core grid plate and directly enter the bottom of the core for operation without the need for a suction extension pipe. Therefore, the suction pipe is shorter, the operation and positioning are more convenient, and the filter component is located at the end of the suction pipe, so the filter component can be quickly removed when suctioning high-level radioactive materials.

[0043] The present application has been described in detail above with reference to the accompanying drawings and embodiments. However, the present application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present application. All content not described in detail in this application can be derived from existing technology.

Claims

1. A suction device for foreign matter at the bottom of a pressure vessel, characterized in that, The device includes: a pump suction assembly (100), a suction pipe (200), and a filter assembly (300); The pump assembly (100) and the filter assembly (300) are connected by a suction pipe (200). The diameters of the pump assembly (100), the suction pipe (200) and the filter assembly (300) are all smaller than the water flow holes on the lower grid plate (501), which are used to extend into the area at the bottom of the reactor pressure vessel (500) through the water flow holes. The pump assembly (100) is used to provide suction for pumping water and includes a power motor (110), an impeller (120) and an impeller cover (130); the power motor (110) is used to drive the impeller (120) to rotate, and the center of the impeller (120) is a hollow area; the impeller cover (130) is located on the outside of the impeller (120) and has an open outlet hole (133); the filter assembly (300) is used to hold the foreign objects being pumped.

2. The suction device for foreign matter at the bottom of a pressure vessel according to claim 1, characterized in that, The impeller (120) includes: a base plate (122) and multiple blades (121); Multiple blades (121) are evenly distributed on the base plate (122), and a hollow area is formed in the middle of the multiple blades (121).

3. The suction device for foreign matter at the bottom of a pressure vessel according to claim 1, characterized in that, The blade (121) has at least two blades.

4. The suction device for foreign matter at the bottom of a pressure vessel according to claim 1, characterized in that, The impeller cover (130) includes: a connecting column (131), a connecting nozzle (132), a top plate (134), and a bottom ring (135). A water inlet hole is provided on the top plate (134), which is connected to the suction pipe (200) through the connecting nozzle (132); The bottom ring (135) is fixedly connected to the power motor (110), and the top plate (134) and the bottom ring (135) are fixedly connected by multiple connecting columns (131). The impeller (120) is set between the top plate (134) and the bottom ring (135); a water outlet (133) is formed between two adjacent connecting columns (131).

5. The suction device for foreign matter at the bottom of a pressure vessel according to any one of claims 1-4, characterized in that, The filter assembly (300) includes: a filter assembly housing (310) and a filter element (320); The filter assembly housing (310) is connected to the suction tube (200); the filter element (320) is installed inside the filter assembly housing (310) to hold the suctioned foreign objects.

6. The suction device for foreign matter at the bottom of a pressure vessel according to claim 5, characterized in that, The filter element (320) includes: a filter screen (321) and a suction nozzle (322); The suction nozzle (322) is located at the front end of the filter assembly housing (310) and is in communication with the outside. The filter (321) is located on the rear side of the suction nozzle (322) and contains the foreign objects being suctioned.

7. The suction device for foreign matter at the bottom of a pressure vessel according to claim 6, characterized in that, A one-way valve (323) is provided between the filter screen (321) and the suction nozzle (322).

8. The suction device for foreign matter at the bottom of a pressure vessel according to any one of claims 1-4, characterized in that, The power motor (110) is a pneumatic motor or an electric motor; the suction tube (200) is flexible.

9. The suction device for foreign matter at the bottom of a pressure vessel according to any one of claims 1-4, characterized in that, The device also includes: a long-handled tool (400). A long-hand tool (400) is connected to a pump assembly (100) for extending the pump assembly (100), suction pipe (200), and filter assembly (300) into the area through the water outlet for operation, and for withdrawing the pump assembly (100), suction pipe (200), and filter assembly (300) from the area for operation.

10. A method for suctioning foreign matter from the bottom of a pressure vessel, characterized in that, The method, applied to the suction device for foreign matter at the bottom of a pressure vessel according to any one of claims 1-9, comprises: The device is inserted through the water inlet into the area at the bottom of the reactor pressure vessel (500) for operation; Adjust the orientation of the device so that the filter assembly (300) is pointing towards the foreign object; The power motor (110) is started to drive the impeller (120) to rotate. The hollow area in the middle of the impeller (120) forms a negative pressure to pump water. Water is thrown out from the outlet (133) and the foreign matter is sucked into the filter assembly (300).

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