Cleaning device for external heat exchanger of nuclear power station main pump

Abstract

The utility model provides a cleaning device for an external heat exchanger of a main pump of a nuclear power station. The cleaning device comprises a filtering device, a cleaning water tank and a first flushing water conveying device which are connected in sequence, the filtering device comprises a first filter and a second filter which are arranged in sequence; the cleaning device further comprises a second flushing water conveying device and a third filter. And the cleaning water tank, the second flushing water conveying device, the third filter and the second filter are circularly connected. The cleaning device cyclically cleans the heat exchanger through chemical agents in the cleaning water tank, the rust removal effect is good, and the cleaning device is suitable for large-scale application and popularization.

Description

Technical Field

[0001] This utility model relates to the field of heat exchanger rust removal technology, and in particular to a cleaning device for an external heat exchanger of a nuclear power plant main pump. Background Technology

[0002] The AP / CAP series nuclear power plant main pump external heat exchanger consists of a primary side (tube side) and a secondary side (shell side) of a shell-and-tube heat exchanger. The tube side is connected to the primary loop cooling water and forms the pressure boundary. After manufacturing, the AP / CAP series main pumps require extensive testing. During this testing process, corrosion can occur in the heat exchanger. If this corrosion is not addressed promptly, the following problems will arise: 1. Corrosion products from the tube side will detach and enter the main pump's lubricating water as foreign matter. This can cause wear on components such as the main pump bearings and thrust disc, and in severe cases, destructive damage or even complete failure of the main pump; 2. If corrosion products are not treated promptly, they will continue to corrode over time, leading to primary loop leaks; 3. Corrosion products will affect heat exchange efficiency.

[0003] The existing AP / CAP series nuclear power plant main pump external heat exchanger rust removal and cleaning requires special agents and the process is complicated. However, the manufacturer does not have dedicated cleaning facilities, which results in low cleaning efficiency and poor effect.

[0004] CN210400153U discloses a rapid cleaning device for heat exchangers, including a housing. A liquid storage tank is fixedly connected to the inner cavity of the housing. The top of the liquid storage tank has a water inlet, and the bottom has a water outlet. A four-way valve A is fixedly connected to the water outlet at the bottom of the liquid storage tank via a water pipe A. A water pump is fixedly connected to the water outlet of the four-way valve A via a water pipe B. A water pipe C is fixedly connected to the water outlet of the water pump. A pipe connector A is fixedly connected to the other end of water pipe C. A water pipe D is fixedly connected to the water inlet of the liquid storage tank. A four-way valve B is fixedly connected to the other end of water pipe D. The water inlet of the four-way valve B is fixedly connected to a pipe connector B via a water pipe E. This design with multiple liquid storage tanks allows for repeated rinsing of the heat exchanger, removing scale from the inside of the heat exchanger and preventing damage to the heat exchanger during the cleaning process.

[0005] CN219714155U discloses a cleaning device for finned heat exchangers, including a housing. Support legs are fixedly connected to the four corners of the bottom of the housing, and bases are fixedly connected to the bottom of the support legs. A cleaning chamber is located on the top of the housing. Clamping assemblies are provided on both sides of the cleaning chamber. A vertical plate is located at the rear of the cleaning chamber. A groove is formed at the top of the vertical plate, and a movable plate is rotatably connected inside the groove. A water spray assembly is located at the bottom of the movable plate. Through the cooperation of a hydraulic cylinder, hydraulic rod, fixed plate, slide groove, slide bar, spring, slider, first clamping plate, second clamping plate, water spray assembly, and filter screen, an automatic cleaning effect is achieved. The cleaning effect is good, solving the technical problem of low cleaning efficiency caused by manual cleaning in the prior art, reducing the workload of workers, and improving the cleaning speed.

[0006] CN114838616A discloses a cleaning device for heat exchangers, a heat exchanger, and a heat pump unit. The cleaning device is configured to be placed inside the heat exchanger to clean the interior of the heat exchanger tubes. It includes a main body, a telescopic member, and a first driving member. The main body is fixedly connected to the heat exchanger. The telescopic member is provided with a brush structure. The first driving member is connected to the main body and is configured to drive the telescopic member to rotate, causing the brush structure to rotate accordingly and thus cleaning the interior of the heat exchanger tubes. The cleaning device, through the combined arrangement of the first driving member and the telescopic member, can effectively clean the interior of the heat exchanger tubes by rotational cleaning. Furthermore, it can selectively change the extension length of the telescopic member according to the length of the heat exchanger tubes to effectively ensure the cleaning range and cleaning effect.

[0007] However, the aforementioned heat exchanger cleaning device has the problem that its structure is relatively complex and it is not suitable for cleaning the external heat exchangers of the main pumps in nuclear power plants. Utility Model Content

[0008] In view of the problems existing in the prior art, the present invention provides a cleaning device for the external heat exchanger of the main pump of a nuclear power plant. By connecting the cleaning device to the shell side of the external heat exchanger of the main pump of the nuclear power plant in a circulating connection, the rust products inside the heat exchanger are cleaned and removed by the chemical agent in the cleaning water tank. Moreover, the chemical agent can be dissolved in the cleaning water tank in a circulating manner without the need for stirring and mixing, and the operation is simple.

[0009] To achieve this objective, the present invention adopts the following technical solution:

[0010] This utility model provides a cleaning device for an external heat exchanger of a main pump in a nuclear power plant. The cleaning device includes a filter device, a cleaning water tank, and a first flushing water conveying device connected in sequence. The filter device includes a first filter and a second filter arranged in sequence.

[0011] The cleaning device also includes a second flushing water delivery device and a third filter; the cleaning water tank, the second flushing water delivery device, the third filter and the second filter are connected in a loop.

[0012] The cleaning device for the external heat exchanger of the main pump in a nuclear power plant, as described in this invention, has a simple structure and is easy to operate. It fully considers the material tolerance of the external heat exchanger and the requirements of the primary loop for halogens and sulfate ions, employing a chemical agent for circulating cleaning. The cleaning device is connected to the inlet and outlet of the external heat exchanger shell to form a circulation loop. The chemical agent in the cleaning tank removes rust products from the heat exchanger. The cleaning solution is then filtered to remove impurities and returned to the cleaning tank for continued circulating cleaning of the heat exchanger. The chemical agent not only removes rust products from the shell of the external heat exchanger but also forms a passivation film, reducing the corrosion rate.

[0013] This invention also includes a second rinsing water delivery device, a third filter, and a second filter that are circulated and connected to the cleaning water tank. This allows the chemicals added to the cleaning water tank to circulate and dissolve quickly, eliminating the need for an additional stirring device and reducing the cost of the cleaning device.

[0014] In this invention, the first flushing water conveying device is used to convey the chemical agent solution in the cleaning water tank to remove rust and clean the shell side of the external heat exchanger of the main pump of the nuclear power plant. The second flushing water conveying device is used to convey the solution in the cleaning water tank to dissolve the chemical agent. Therefore, the flow rate of the first flushing water conveying device is greater than that of the second flushing water conveying device.

[0015] The first and third filters of this invention can be filters commonly used in the field, such as cloth-coated filters.

[0016] Preferably, a water inlet pipe is provided on one side of the cleaning water tank, and a drain pipe is provided at the bottom.

[0017] Preferably, the drainage pipe is equipped with a drainage control valve.

[0018] Preferably, the first flushing water delivery device is connected to the shell-side inlet of the external heat exchanger of the main pump of the nuclear power plant via a first pipeline.

[0019] Preferably, the first pipeline also includes a first valve and a second valve.

[0020] Preferably, the first valve and the second valve are respectively located on both sides of the first flushing water conveying device.

[0021] Preferably, a third valve and a fourth valve are provided on both sides of the second flushing water conveying device.

[0022] Preferably, the second flushing water delivery device is connected to the third filter via a second pipe.

[0023] Preferably, a fifth valve is also provided on the second pipeline.

[0024] Preferably, the first filter is connected to the shell-side outlet of the external heat exchanger of the main pump of the nuclear power plant via a third pipe.

[0025] Preferably, the third pipeline also has a sixth valve.

[0026] Preferably, the second filter includes a replaceable filter element, which allows for timely replacement of the filter element, ensuring that the chemical solution in the cleaning water tank effectively cleans and removes rust products from the heat exchanger.

[0027] The method of using the cleaning device for the external heat exchanger of the main pump in a nuclear power plant according to this utility model includes the following steps:

[0028] (1) Connecting equipment: The first flushing water delivery device in the cleaning device is connected to the shell-side inlet of the external heat exchanger of the main pump of the nuclear power plant by the first pipe, the second flushing water delivery device is connected to the third filter by the second pipe, and the first filter is connected to the shell-side outlet of the external heat exchanger of the main pump of the nuclear power plant by the third pipe.

[0029] (2) Dissolving the agent: Add the chemical agent to the cleaning water tank, close the first valve, the second valve, the sixth valve and the drain control valve, open the third valve and the fifth valve, start the second flushing water delivery device and open the fourth valve to circulate and dissolve the agent; after the chemical agent has dissolved, stop the second flushing water delivery device and close the third valve, the fourth valve and the fifth valve.

[0030] (3) Cyclic operation: Open the first valve and the sixth valve, start the first flushing water delivery device, slowly open the second valve, and the external heat exchanger of the nuclear power plant main pump performs water injection, air venting, circulating acid washing or circulating passivation, etc.; after the work is completed, stop the first flushing water delivery device and close the first valve, the second valve and the sixth valve.

[0031] (4) Cleaning and draining: Open the drain control valve to drain the cleaning water tank.

[0032] Compared with the prior art, the present invention has at least the following beneficial effects:

[0033] The cleaning device for external heat exchangers of nuclear power plant main pumps provided by this utility model has a simple structure and simple operation method. It uses chemical agents in the cleaning water tank for circulating cleaning, which has a good cleaning effect, achieves rust removal, and reduces the corrosion rate. No equipment disassembly is required, the cleaning cost is low, and it can meet various process requirements for cleaning external heat exchangers of nuclear power plant main pumps. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the cleaning device for the external heat exchanger of the main pump in a nuclear power plant, according to a specific embodiment of this utility model.

[0035] In the diagram: 1-Cleaning water tank; 2-First flushing water conveying device; 3-Second flushing water conveying device; 4-Third filter; 5-First filter; 6-Second filter; 7-First valve; 8-Second valve; 9-Third valve; 10-Fourth valve; 11-Fifth valve; 12-Sixth valve; 13-Third pipe; 14-Second pipe; 15-First pipe; 16-Drainage control valve; 17-Water injection pipe. Detailed Implementation

[0036] The technical solution of this utility model will be further described below with reference to the accompanying drawings and specific embodiments.

[0037] The present invention will now be described in further detail. However, the examples described below are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be determined by the claims.

[0038] It should be understood that in the description of this utility model, the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used solely for the convenience of describing this utility model and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0039] It should be noted that, in the description of this utility model, unless otherwise explicitly specified and limited, the terms "set," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0040] Those skilled in the art should understand that this utility model necessarily includes the necessary pipelines, conventional valves and general pump equipment for achieving complete process, but the above content is not the main utility model point of this utility model. Those skilled in the art can add layouts based on process flow and equipment structure selection. This utility model does not make any special requirements or specific limitations in this regard.

[0041] As a specific embodiment of this utility model, a cleaning device for an external heat exchanger of a nuclear power plant main pump is provided, the structural schematic diagram of which is shown below. Figure 1 As shown.

[0042] The cleaning device includes a filter device, a cleaning water tank 1, and a first rinsing water delivery device 2 connected in sequence; the filter device includes a first filter 5 and a second filter 6 arranged in sequence.

[0043] The cleaning device also includes a second flushing water delivery device 3 and a third filter 4; the cleaning water tank 1, the second flushing water delivery device 3, the third filter 4 and the second filter 6 are connected in a loop.

[0044] A water inlet pipe 17 is provided on one side of the cleaning water tank, and a drain pipe is provided at the bottom.

[0045] The drainage pipe is equipped with a drainage control valve 16.

[0046] The first flushing water delivery device 2 is connected to the shell-side inlet of the external heat exchanger of the main pump of the nuclear power plant via the first pipeline 15.

[0047] The first pipeline 15 also has a first valve 7 and a second valve 8;

[0048] The first valve 7 and the second valve 8 are respectively located on both sides of the first flushing water conveying device 2.

[0049] The second flushing water conveying device 3 is provided with a third valve 9 and a fourth valve 10 on both sides.

[0050] The second flushing water delivery device 3 and the third filter 4 are connected via a second pipe 14.

[0051] A fifth valve 11 is also installed on the second pipe 14.

[0052] The first filter 5 is connected to the shell-side outlet of the external heat exchanger of the main pump of the nuclear power plant via the third pipe 13.

[0053] The third pipeline 13 also has a sixth valve 12.

[0054] The second filter 6 includes a replaceable filter cartridge.

[0055] As a specific embodiment of this utility model, a method for using the above-mentioned cleaning device for the external heat exchanger of the main pump of a nuclear power plant is also provided, including the following steps:

[0056] (1) Connecting equipment: The first flushing water conveying device 2 in the cleaning device is connected to the shell-side inlet of the external heat exchanger of the main pump of the nuclear power plant using the first pipe 15, the second flushing water conveying device 3 is connected to the third filter 4 using the second pipe 14, and the first filter 5 is connected to the shell-side outlet of the external heat exchanger of the main pump of the nuclear power plant using the third pipe 13.

[0057] (2) Dissolving the agent: Add the chemical agent to the cleaning water tank 1, close the first valve 7, the second valve 8, the sixth valve 12 and the drain control valve 16, open the third valve 9 and the fifth valve 11, start the second flushing water delivery device 3 and open the fourth valve 10 to circulate and dissolve the agent; after the chemical agent has dissolved, stop the second flushing water delivery device 3 and close the third valve 9, the fourth valve 10 and the fifth valve 11.

[0058] (3) Cyclic operation: Open the first valve 7 and the sixth valve 12, start the first flushing water delivery device 2, slowly open the second valve 8, and the external heat exchanger of the nuclear power plant main pump performs water injection, air venting, circulating acid washing or circulating passivation, etc.; after the work is completed, stop the first flushing water delivery device 2, and close the first valve 7, the second valve 8 and the sixth valve 12.

[0059] (4) Cleaning and draining: Open the drain control valve 16 to drain the cleaning water tank 1.

[0060] In summary, the cleaning device for external heat exchangers of nuclear power plant main pumps provided by this utility model has a simple structure and simple operation method. It uses chemical agents in the cleaning water tank for circulating cleaning, which has a good cleaning effect, does not require equipment disassembly, has low cleaning cost, and has a promising prospect for widespread application.

[0061] The applicant declares that the detailed structural features of this utility model are illustrated through the above embodiments, but this utility model is not limited to the above detailed structural features, that is, it does not mean that this utility model must rely on the above detailed structural features to be implemented. Those skilled in the art should understand that any improvements to this utility model, equivalent substitutions of selected components, additions of auxiliary components, and selection of specific methods, etc., all fall within the protection and disclosure scope of this utility model.

[0062] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

Claims

1. A cleaning device for an external heat exchanger of a nuclear power plant main pump, characterized in that, The cleaning device includes a filter device, a cleaning water tank, and a first rinsing water delivery device connected in sequence; the filter device includes a first filter and a second filter arranged in sequence. The cleaning device also includes a second flushing water delivery device and a third filter; the cleaning water tank, the second flushing water delivery device, the third filter and the second filter are connected in a loop.

2. The cleaning device for the external heat exchanger of the main pump in a nuclear power plant according to claim 1, characterized in that, A water inlet pipe is provided on one side of the cleaning water tank, and a drain pipe is provided at the bottom; The drainage pipe is equipped with a drainage control valve.

3. The cleaning device for the external heat exchanger of the main pump in a nuclear power plant according to claim 1, characterized in that, The first flushing water delivery device is connected to the shell-side inlet of the external heat exchanger of the main pump of the nuclear power plant via a first pipeline.

4. The cleaning device for the external heat exchanger of the main pump in a nuclear power plant according to claim 3, characterized in that, The first pipeline also has a first valve and a second valve; The first valve and the second valve are respectively located on both sides of the first flushing water delivery device.

5. The cleaning device for the external heat exchanger of the main pump in a nuclear power plant according to claim 1, characterized in that, The second flushing water delivery device is equipped with a third valve and a fourth valve on both sides.

6. The cleaning device for the external heat exchanger of the main pump in a nuclear power plant according to claim 1, characterized in that, The second flushing water delivery device is connected to the third filter via a second pipe.

7. The cleaning device for the external heat exchanger of the main pump in a nuclear power plant according to claim 6, characterized in that, A fifth valve is also installed on the second pipeline.

8. The cleaning device for the external heat exchanger of the main pump in a nuclear power plant according to claim 1, characterized in that, The first filter is connected to the shell-side outlet of the external heat exchanger of the main pump of the nuclear power plant via a third pipe.

9. The cleaning device for the external heat exchanger of the main pump in a nuclear power plant according to claim 8, characterized in that, The third pipeline also has a sixth valve.

10. The cleaning device for the external heat exchanger of the main pump in a nuclear power plant according to claim 1, characterized in that, The second filter includes a replaceable cartridge filter.

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