Deoxygenated water supply method and deoxygenated water supply system

Abstract

This application relates to a deoxygenated water supply method and system. The deoxygenated water supply method is applied to the hot functional tests of the nuclear island in a nuclear power plant. The nuclear power plant includes a deoxygenated water supply system, which comprises a feedwater deaerator and a high-pressure feedwater system connected together. The deoxygenated water supply method includes the following steps: adjusting the conventional island demineralized water distribution system as the water source for the deoxygenated water supply system; starting the conventional island demineralized water distribution system so that the water flowing out of the conventional island demineralized water distribution system can clean the pipelines and components between the conventional island demineralized water distribution system and the high-pressure feedwater system; starting the feedwater deaerator and adjusting the water quality flowing to the high-pressure feedwater system. Compared to the traditional water supply scheme where condensate is generated through a condensate extraction system and then flows into the feedwater aerator after passing through a condensate purification system and a low-pressure feedwater heater, the construction time required for supplying water through the conventional island demineralized water distribution system is shorter.

Description

Technical Field

[0001] This application relates to the field of nuclear power plant technology, and in particular to deoxygenated water supply methods and deoxygenated water supply systems. Background Technology

[0002] Nuclear power generation is currently an important method of power generation, but building a nuclear power plant is a time-consuming project. Various experiments are required before a nuclear power plant can be put into operation to prevent potential safety accidents. Among these, the hot functional test of the nuclear island is the most important test, and some components of the nuclear power plant form a deoxygenated water supply system, which is necessary for conducting the hot functional test.

[0003] To reduce construction time, existing nuclear power plants need to conduct hot functional tests as soon as possible. However, traditional deoxygenated water supply methods can only be carried out after the complex water supply system within the nuclear power plant has been completed, which makes it difficult to conduct hot functional tests at an early stage. Summary of the Invention

[0004] Therefore, it is necessary to provide a deoxygenated water supply method and system to address the problem that traditional deoxygenated water supply methods require the completion of a complex water supply system within the nuclear power plant, which makes it difficult to conduct hot functional tests early.

[0005] According to a first aspect of this application, a deoxygenated water supply method is proposed for use in the hot functional test of the nuclear island of a nuclear power plant. The nuclear power plant includes a deoxygenated water supply system, which comprises a feedwater deaerator and a high-pressure feedwater system connected together. The deoxygenated water supply method includes:

[0006] The conventional island demineralized water distribution system is adjusted to be the water supply source of the deoxygenated water supply system, so that the inlet pipe of the conventional island demineralized water distribution system is connected to the water supply deaerator of the deoxygenated water supply system.

[0007] Start the conventional island demineralized water distribution system so that the water flowing out of the conventional island demineralized water distribution system can clean the pipes and components between the conventional island demineralized water distribution system and the high-pressure water supply system;

[0008] Start the water deaerator and adjust the water quality of the water flowing from the conventional island demineralized water distribution system to the high-pressure water supply system.

[0009] In one embodiment, the step of adjusting the conventional island demineralized water distribution system to be the water supply source of the deoxygenated water supply system, so that the inlet pipes of the conventional island demineralized water distribution system and the deoxygenated water supply system are connected, specifically includes:

[0010] The first water supply pipeline between the low-pressure feedwater heater and the feedwater deaerator is cut off, so that the first water supply pipeline has a first section with one end connected to the feedwater deaerator.

[0011] The second water supply pipeline between the conventional island demineralized water distribution system and the water supply deaerator is disconnected, so that the second water supply pipeline has a second section with one end connected to the conventional island demineralized water distribution system;

[0012] Connect the first segment and the second segment to connect the inlet pipe of the conventional island demineralized water distribution system and the deoxygenated water supply system to the water supply deaerator.

[0013] In one embodiment, the first water supply pipeline further has a third section with one end connected to the low-pressure water heater; the second water supply pipeline further has a fourth section with one end connected to the water deaerator; the deaerated water supply system further includes two sealing components;

[0014] The step of adjusting the conventional island demineralized water distribution system to be the water supply source for the deoxygenated water supply system, so that the inlet pipes of the conventional island demineralized water distribution system and the deoxygenated water supply system are connected, further includes:

[0015] The third segment and the fourth segment are respectively sealed by one of the sealing components.

[0016] In one embodiment, the deoxygenated water supply system includes a deaerator recirculation pump, a first water supply pump group, a second water supply pump group, and a sewage collection tank. One end of the deaerator recirculation pump, one end of the first water supply pump group, and one end of the second water supply pump group are connected in parallel to the water supply deaerator. The other end of the deaerator recirculation pump, the other end of the first water supply pump group, and the other end of the second water supply pump group are connected in parallel to the sewage collection tank. A first recirculation isolation valve and an atmospheric pressure flushing valve are provided on a first pipeline between the parallel connection point of one end of the deaerator recirculation pump, one end of the first water supply pump group, and one end of the second water supply pump group and the sewage collection tank.

[0017] The step of activating the conventional island demineralized water distribution system so that the water flowing out of the conventional island demineralized water distribution system can clean the pipelines and components between the conventional island demineralized water distribution system and the high-pressure water supply system includes:

[0018] Start the conventional island demineralized water distribution system and turn on the deaerator recirculation pump, the first recirculation isolation valve and the atmospheric pressure flushing valve;

[0019] Turn off the deaerator recirculation pump and turn on the first feedwater pump group;

[0020] The first water supply pump unit is shut down, and the second water supply pump unit is turned on.

[0021] In one embodiment, a pump group outlet bypass valve and a high-pressure flushing valve are provided on a second pipeline between one end of the first water supply pump group and one end of the second water supply pump group and the sewage collection tank; the deoxygenated water supply system also includes a high-pressure heater bypass and the main water supply header located between the pump group outlet bypass valve and the high-pressure flushing valve.

[0022] After the step of shutting down the first water supply pump group and starting the second water supply pump group, the method further includes:

[0023] Close the first recirculation isolation valve and the atmospheric pressure flushing valve, and open the pump set outlet bypass valve and the high pressure flushing valve;

[0024] The second water supply pump unit is shut down, and the first water supply pump unit is turned on.

[0025] In one embodiment, the deoxygenated water supply system further includes multiple high-pressure heaters for heating the deoxygenated water flowing out of the feedwater deaerator;

[0026] After shutting down the second water supply pump group and turning on the first water supply pump group, the deoxygenated water supply method further includes:

[0027] Shut down the conventional island demineralized water distribution system and the first feedwater pump group, and open the manhole doors of the feedwater deaerator and each of the high-pressure heaters to remove foreign objects from the feedwater deaerator and each of the high-pressure heaters.

[0028] In one embodiment, the deoxygenated water supply system further includes an auxiliary steam system connected to the feedwater deaerator; the main feedwater header is connected to the high-pressure feedwater system, and a second recirculation isolation valve is provided between the main feedwater header and the high-pressure feedwater system;

[0029] The steps of starting the feedwater deaerator and adjusting the water quality flowing from the conventional island demineralized water distribution system to the high-pressure feedwater system include:

[0030] Start the conventional island demineralized water distribution system;

[0031] Start the auxiliary steam system to input steam into the feedwater deaerator;

[0032] An acid-base regulator is added to the water storage chamber of the water deaerator to adjust the pH value of the deoxygenated water in the water deaerator to a preset pH range.

[0033] Open the first water supply pump set, the pump set outlet bypass valve, and the second recirculation isolation valve;

[0034] The first water supply pump group is shut down, and the second water supply pump group is turned on;

[0035] Shut down the second water supply pump set and start the deaerator recirculation pump.

[0036] In one embodiment, the pH value is preset to a range of 8.8 to 10.

[0037] According to a second aspect of this application, a deoxygenated water supply system is also provided for implementing the deoxygenated water supply method as described above, the deoxygenated water supply system comprising:

[0038] A water deaerator, internally equipped with nozzles, includes a deaerator for deoxygenating the water sprayed from the nozzles to supply deoxygenated water to various pipelines and components of the deoxygenated water supply system; and

[0039] A conventional island demineralized water distribution system is connected to the nozzles and is used to supply water to the feedwater deaerator.

[0040] In one embodiment, the nuclear power plant further includes a low-pressure feedwater heater; a first water supply pipeline is provided between the low-pressure feedwater heater and the feedwater deaerator, the first water supply pipeline being disconnected, such that the first water supply pipeline has a first section with one end connected to the feedwater deaerator and a third section with one end connected to the low-pressure feedwater heater.

[0041] A second water supply pipeline is provided between the conventional island demineralized water distribution system and the feedwater deaerator. The second water supply pipeline is disconnected, so that the second water supply pipeline has a second section with one end connected to the conventional island demineralized water distribution system and a fourth section with one end connected to the feedwater deaerator; the first section is connected to the second section.

[0042] The deaerator supply system also includes two sealing components, which are used to seal the opening of the third section and the opening of the fourth section, respectively.

[0043] In the technical solution of this application, the conventional island demineralized water distribution system in the nuclear power plant is adjusted to become the water source for the deoxygenated water supply system by modifying the water pipeline. The conventional island demineralized water distribution system requires less construction time. Therefore, compared to the traditional water supply scheme where condensate is generated through a condensate extraction system and then flows into the feedwater oxygenator after passing through a condensate purification system and a low-pressure feedwater heater, the conventional island demineralized water distribution system allows for earlier hot functional testing.

[0044] Following this, the various components and pipelines in the deoxygenated water supply system need to be flushed and cleaned using the conventional island demineralized water distribution system to ensure they meet the requirements of the hot functional test. Subsequently, the water quality flowing from the conventional island demineralized water distribution system to the high-pressure water supply system is adjusted within the cleaned components and pipelines to ensure it meets the requirements of the hot functional test. The deoxygenated water supply method proposed in this application allows the hot functional test to be conducted earlier by adjusting the water source to the conventional island demineralized water distribution system. Furthermore, by cleaning the pipelines and components and adjusting the water quality, the water supply requirements for the hot functional test are met, enabling the test to be carried out ahead of schedule. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of a portion of the structure of an embodiment of the deoxygenated water supply system proposed in this application.

[0046] Figure 2 for Figure 1 A schematic diagram of another part of the deoxygenated water supply system;

[0047] Figure 3 This is a schematic flowchart of the first embodiment of the deoxygenated water supply method proposed in this application;

[0048] Figure 4 This is a schematic flowchart of the second embodiment of the deoxygenated water supply method proposed in this application;

[0049] Figure 5 This is a schematic flowchart of the third embodiment of the deoxygenated water supply method proposed in this application;

[0050] Figure 6 This is a schematic flowchart of the fourth embodiment of the deoxygenated water supply method proposed in this application;

[0051] Figure 7 This is a schematic flowchart of the fifth embodiment of the deoxygenated water supply method proposed in this application.

[0052] Explanation of icon numbers:

[0053] Detailed Implementation

[0054] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0055] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and 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, and therefore should not be construed as a limitation of this application.

[0056] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0057] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0058] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0059] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0060] Nuclear power generation is currently the most important method of power generation, but building a nuclear power plant is a time-consuming project. Various experiments are required before a nuclear power plant can be put into operation to prevent potential safety accidents. Among these, the hot functional test of the nuclear island is the most crucial test, and some components of the nuclear power plant form a deoxygenated water supply system, which is essential for conducting the hot functional test.

[0061] To reduce construction time, existing nuclear power plants need to conduct hot functional tests as soon as possible. However, traditional deoxygenated water supply methods can only be carried out after the complex water supply system within the nuclear power plant has been completed, which makes it difficult to conduct hot functional tests at an early stage.

[0062] The inventors of this application discovered through research that in traditional water supply schemes, condensate is generated through a condensate extraction system. The condensate then flows into the feedwater oxygenator after passing through a condensate purification system and a low-pressure feedwater heater. This means that hot functional tests can only be carried out after the condensate extraction system, condensate purification system, and low-pressure feedwater heater have all been completed, resulting in a long construction time.

[0063] Figures 1 to 2 This is a schematic diagram of an embodiment of the deoxygenated water supply system proposed in this application.

[0064] Please see Figure 1 This application first proposes a deoxygenated water supply system 100, which includes a feedwater deaerator 1 and a conventional island demineralized water distribution system 2. The feedwater deaerator 1 is equipped with nozzles and includes a deaerator for deoxygenating the water sprayed from the nozzles, supplying deoxygenated water to various pipelines and components of the deoxygenated water supply system 100. The conventional island demineralized water distribution system 2 is connected to the nozzles and supplies water to the feedwater deaerator 1.

[0065] In the deoxygenated water supply system 100 proposed in this application, water is supplied to the feedwater deaerator 1 through the conventional island demineralized water distribution system 2. The conventional island demineralized water distribution system 2 is connected to the nozzles inside the feedwater deaerator 1, thereby enabling the feedwater deaerator 1 to supply deoxygenated water to various pipelines and components for hot functional testing. Compared to the condensate extraction system, condensate purification system, and low-pressure feedwater heater 200, the conventional island demineralized water distribution system 2 requires less construction time. Therefore, the deoxygenated water supply system 100 proposed in this application can solve the water supply problem for hot functional testing earlier, thereby enabling the hot functional testing to be carried out more quickly.

[0066] In some embodiments, the nuclear power plant further includes a low-pressure feedwater heater 200, and a first water supply pipeline 210 is provided between the low-pressure feedwater heater 200 and the feedwater deaerator 1. The first water supply pipeline 210 is disconnected, such that the first water supply pipeline 210 has a first section 220 connected at one end to the feedwater deaerator 1 and a third section 230 connected at one end to the low-pressure feedwater heater 200.

[0067] A second water supply pipeline 21 is provided between the conventional island demineralized water distribution system 2 and the feedwater deaerator 1. The second water supply pipeline 21 is disconnected, so that the second water supply pipeline 21 has a second section 211 connected to the conventional island demineralized water distribution system 2 at one end and a fourth section 212 connected to the feedwater deaerator 1 at the other end. The first section 220 is connected to the second section 211. The deaerator supply system also includes two sealing components 3, which are used to seal the opening of the third section 230 and the opening of the fourth section 212, respectively.

[0068] In practical applications, the first water supply pipeline 210 and the second water supply pipeline 21 can be disconnected. This results in the first water supply pipeline 210 having a first section 220 connected to the feedwater deaerator 1 at one end and a third section 230 connected to the low-pressure feedwater heater 200 at the other end. The second water supply pipeline 21 has a second section 211 connected to the conventional island demineralized water distribution system 2 at one end and a fourth section 212 connected to the feedwater deaerator 1 at the other end. When the first section 220 and the second section 211 are connected, the conventional island demineralized water distribution system 2 can supply water to the feedwater deaerator 1.

[0069] At this point, the third section 230 and the fourth section 212 are open, which may affect the hot functional test. Therefore, the deoxygenated water supply system 100 also includes a sealing component 3 to seal the third section 230 and the fourth section 212, thereby ensuring the normal conduct of the hot functional test.

[0070] Based on the aforementioned hardware conditions, this application also proposes a method for supplying deoxygenated water. Figures 3 to 7 This is a schematic flowchart of an embodiment of the deoxygenated water supply method proposed in this application.

[0071] Please see Figure 3 The deoxygenated water supply method is applied to the hot functional test of the nuclear island in a nuclear power plant. The nuclear power plant includes a deoxygenated water supply system 100, which includes a connected feedwater deaerator 1 and a high-pressure feedwater system. The deoxygenated water supply method includes:

[0072] S10. Adjust the conventional island demineralized water distribution system 2 to be the water supply source of the deoxygenated water supply system 100, so that the inlet pipe of the conventional island demineralized water distribution system 2 is connected to the water supply deaerator 1 of the deoxygenated water supply system 100.

[0073] S20. Start the conventional island demineralized water distribution system 2 so that the water flowing out of the conventional island demineralized water distribution system 2 can clean the pipes and components between the conventional island demineralized water distribution system 2 and the high-pressure water supply system.

[0074] S30. Start the water supply deaerator 1 and adjust the water quality of the water flowing from the conventional island demineralized water distribution system 2 to the high-pressure water supply system.

[0075] In the technical solution of this application, the conventional island demineralized water distribution system 2 in the nuclear power plant is adjusted to become the water source for the deoxygenated water supply system 100 by modifying the water pipeline in the nuclear power plant. The construction time required for the conventional island demineralized water distribution system 2 is shorter. Therefore, compared with the traditional water supply scheme that generates condensate through a condensate extraction system, and the condensate flows into the feedwater oxygenator after passing through a condensate purification system and a low-pressure feedwater heater 200, the conventional island demineralized water distribution system 2 can supply water for hot functional tests earlier.

[0076] Following this, the various components and pipelines in the deoxygenated water supply system 100 need to be flushed and cleaned using the conventional island demineralized water distribution system 2, so that the components and pipelines in the deoxygenated water supply system 100 can meet the requirements of the hot functional test. Subsequently, in the clean components and pipelines, the water quality of the water flowing from the conventional island demineralized water distribution system 2 to the high-pressure water supply system is adjusted, so that the water flowing from the conventional island demineralized water distribution system 2 to the high-pressure water supply system can meet the requirements of the hot functional test. The deoxygenated water supply method proposed in this application allows the hot functional test to be carried out in advance by adjusting the water supply source to the conventional island demineralized water distribution system 2, and by cleaning the pipelines and components and adjusting the water quality, the test requirements of the hot functional test are met, allowing the hot functional test to be carried out in advance.

[0077] Please see Figure 4 In some embodiments, step S10 specifically includes:

[0078] S11. Disconnect the first water supply pipeline 210 between the low-pressure feedwater heater 200 and the feedwater deaerator 1, so that the first water supply pipeline 210 has a first section 220 connected at one end to the feedwater deaerator 1. In the prior art, the nozzles of the low-pressure feedwater heater 200 and the feedwater deaerator 1 in a nuclear power plant are connected through the first water supply pipeline 210. Disconnecting the first water supply pipeline 210 divides it into two sections, with the first section 220 connected to the feedwater deaerator 1 and the other section connected to the low-pressure feedwater heater 200. Disconnecting the first water supply pipeline 210 disconnects the low-pressure feedwater heater 200 from the feedwater deaerator, thereby facilitating subsequent replacement of the water supply source.

[0079] S12. Disconnect the second water supply pipeline 21 between the conventional island demineralized water distribution system 2 and the feedwater deaerator 1, so that the second water supply pipeline 21 has a second section 211 connected at one end to the conventional island demineralized water distribution system 2. The conventional island demineralized water distribution system 2 is connected to the other parts of the feedwater deaerator 1 through the second water supply pipeline 21. Disconnecting the second water supply pipeline 21 divides it into two sections. The second section 211 is connected to the conventional island demineralized water distribution system 2, and the other section is connected to the feedwater deaerator 1. After disconnecting the second water supply pipeline 21, the conventional island demineralized water distribution system 2 will no longer supply water to the other parts of the feedwater deaerator 1.

[0080] S13. Connect the first section 220 and the second section 211 to connect the inlet pipes of the conventional island demineralized water distribution system 2 and the feedwater deaerator 1 of the deoxygenated water supply system 100. Connecting the first section 220 and the second section 211 allows the nozzles of the conventional island demineralized water distribution system 2 and the feedwater deaerator 1 to be connected, thus enabling the conventional island demineralized water distribution system 2 to supply water to the feedwater deaerator 1, thereby replacing the conventional island demineralized water distribution system 2 as the water supply source. The construction time required for the conventional island demineralized water distribution system 2 is relatively short, allowing the hot functional test to be carried out earlier.

[0081] In some embodiments, the first water supply line 210 further has a third section 230 connected at one end to the low-pressure water heater 200, and the second water supply line 21 further has a fourth section 212 connected at one end to the water deaerator 1. The deaerated water supply system 100 also includes two sealing components 3.

[0082] Step S10 also includes: S14, sealing the third segment 230 and the fourth segment 212 respectively through a sealing plug 3.

[0083] After the first water supply pipe 210 is cut, it has a first section 220 connected to the feedwater deaerator 1 and a third section 230 connected to the low-pressure feedwater heater 200. After the second water supply pipe 21 is cut, it has a second section 211 connected to the conventional island demineralized water distribution system 2 and a fourth section 212 connected to the feedwater deaerator 1. After connecting the first section 220 and the second section 211, the conventional island demineralized water distribution system 2 supplies water to the feedwater deaerator 1. However, keeping the third section 230 and the fourth section 212 open may affect subsequent tests. Therefore, in one embodiment of this application, the deoxygenated water supply system 100 also includes two sealing members 3 to seal the third section 230 and the fourth section 212 respectively, thereby ensuring the smooth progress of the hot functional test.

[0084] In some embodiments, the deoxygenated water supply system 100 includes a deaerator recirculation pump, a first feed water pump group 8, a second feed water pump group 9, and a wastewater collection tank 5. One end of the deaerator recirculation pump, one end of the first feed water pump group 8, and one end of the second feed water pump group 9 are connected in parallel to the feed water deaerator 1, and the other ends of the deaerator recirculation pump, the first feed water pump group 8, and the second feed water pump group 9 are connected in parallel to the wastewater collection tank 5. A first recirculation isolation valve 6 and an atmospheric pressure flushing valve 4 are provided on the first pipeline between the parallel connection point of one end of the deaerator recirculation pump, one end of the first feed water pump group 8, and one end of the second feed water pump group 9 and the wastewater collection tank 5.

[0085] Please see Figure 5 Step S20 includes:

[0086] S21. Start the conventional island demineralized water distribution system 2 and open the deaerator recirculation pump, the first recirculation isolation valve 6, and the atmospheric pressure flushing valve 4. Starting the conventional island demineralized water distribution system 2 supplies water to the feedwater deaerator 1. At this time, opening the deaerator recirculation pump will draw water out of the feedwater deaerator 1, and the water will flow towards the wastewater collection tank 5 after passing through the deaerator recirculation pump. During the flow, the water will pass through the first recirculation isolation valve 6 and the atmospheric pressure flushing valve 4, therefore, both the first recirculation isolation valve 6 and the atmospheric pressure flushing valve 4 need to be opened simultaneously. During the flow, the water will flush the pipes between the deaerator recirculation pump, the first recirculation isolation valve 6, and the atmospheric pressure flushing valve 4. Therefore, the conventional island demineralized water distribution system 2 can only be closed when the water flowing into the wastewater collection tank 5 is clear.

[0087] S22. Turn off the deaerator recirculation pump and turn on the first feed water pump group 8. When the water flowing into the sewage collection tank 5 remains clear when the deaerator recirculation pump is turned on, it indicates that the pipeline where the deaerator recirculation pump is located has been flushed clean. At this time, the deaerator recirculation pump can be turned off and the first feed water pump group 8 can be turned on to clean the first feed water pump group 8.

[0088] S23. Turn off the first water supply pump group 8 and turn on the second water supply pump group 9. Similarly, when the water flowing into the sewage collection tank 5 remains clear when the first water supply pump group 8 is turned on, it indicates that the pipeline where the first water supply pump group 8 is located has been flushed clean. At this time, the first water supply pump group 8 can be turned off and the second water supply pump group 9 can be turned on to clean the pipeline connected to the second water supply pump group 9.

[0089] In practice, the first feedwater pump group 8 can be either the start-up feedwater pump group or the electric feedwater pump group in a nuclear power plant, and the second feedwater pump group 9 can be the other one. Furthermore, the starting sequence of the deaerator recirculation pump, the first feedwater pump group 8, and the second feedwater pump group 9 is not fixed and can be adjusted according to actual conditions.

[0090] It should be noted that the atmospheric pressure flushing valve 4 is designed specifically for the flushing work in the early stage of the hot functional test. After the flushing work for the hot functional test is completed, the atmospheric pressure flushing valve 4 should be removed to avoid affecting the subsequent hot functional test. In addition, other temporary pipelines and temporary devices related to the flushing work should also be disassembled to avoid affecting the subsequent hot functional test.

[0091] In some embodiments, a pump group outlet bypass valve 10 and a high-pressure flushing valve 101 are provided on a second pipeline between one end of the first water supply pump group 8 and one end of the second water supply pump group 9 and the sewage collection tank 5. The deoxygenated water supply system 100 also includes a high-pressure heater bypass 71 and a main water supply header located between the pump group outlet bypass valve 10 and the high-pressure flushing valve 101.

[0092] Please see Figure 2 and Figure 6 Step S23 is followed by:

[0093] S24. Close the first recirculation isolation valve 6 and the atmospheric pressure flushing valve 4, and open the pump set outlet bypass valve 10 and the high-pressure flushing valve 101. This will prevent the water pumped from the deaerator recirculation pump, the first feedwater pump set 8, and the second feedwater pump set 9 from passing through the feedwater deaerator 1 from the first recirculation isolation valve 6 and the atmospheric pressure flushing valve 4. Instead, the water will flow sequentially through the pump set outlet bypass valve 10, the high-pressure heater bypass 71, the main feedwater header, and the high-pressure flushing valve 101 before flowing into the sewage collection tank 5. In this step, by closing the previously opened first recirculation isolation valve 6 and the atmospheric pressure flushing valve 4, and opening the pump set outlet bypass valve 10 and the high-pressure flushing valve 101, the direction of water flow is changed, thereby flushing more pipes. It should be noted that the second feedwater pump set 9, which was opened in step S23, is not closed. Therefore, the water is still flowing in the pipes at this time, and the water flow will flush the pipes between the pump set outlet bypass valve 10, the high-pressure heater bypass 71, the main feedwater header, and the high-pressure flushing valve 101.

[0094] S25. Close the second water supply pump group 9 and open the first water supply pump group 8. When the water flowing into the sewage collection tank 5 becomes clear, it indicates that the pipeline between the second water supply pump group 9 and the sewage collection tank 5, which passes through the pump group outlet bypass valve 10, the high-pressure heater bypass 71, the main water supply header, and the high-pressure flushing valve 101 in sequence, has been basically flushed clean. Therefore, the second water supply pump group 9 can be closed at this time, and the first water supply pump group 8 can be opened to flush the pipeline between the first water supply pump group 8 and the sewage collection tank 5, which passes through the pump group outlet bypass valve 10, the high-pressure heater bypass 71, the main water supply header, and the high-pressure flushing valve 101 in sequence, thus cleaning the high-pressure water pipeline during the hot functional test.

[0095] In some embodiments, the deoxygenated water supply system 100 further includes a plurality of high-pressure heaters 7 for heating the deoxygenated water flowing out of the feedwater deaerator 1. After step S25, the deoxygenated water supply method further includes:

[0096] S26. Close the conventional island demineralized water distribution system 2 and the first feedwater pump group 8, and open the manhole doors of the feedwater deaerator 1 and each high-pressure heater 7 to clean the foreign objects in the feedwater deaerator 1 and each high-pressure heater 7.

[0097] After implementing steps S21 to S23, the atmospheric pressure water pipes in the deoxygenated water supply system 100 can be cleaned, and after implementing steps S24 to S25, the high-pressure water pipes in the deoxygenated water supply system 100 can be cleaned. However, this does not mean that the pipelines in the deoxygenated water supply system 100 are clean; in fact, there may be foreign matter that is difficult to remove remaining in the container or on the various filter screens. Therefore, in this embodiment, the conventional island demineralized water distribution system 2 and the first water pump group, which are still in operation, can be shut down first, thereby stopping the water supply to the deoxygenated water supply system 100. At this time, the manhole doors of the feedwater deaerator 1 and each high-pressure heater 7 are opened, so that inspectors can enter the chambers of the feedwater deaerator 1 and each high-pressure heater 7, thereby allowing inspectors to clean the foreign matter accumulated in each chamber.

[0098] In addition, foreign objects may accumulate on the filters of each water pump, so inspectors can use tools such as endoscopes to clean the filters of each water pump, thereby ensuring the cleanliness of the pipes and various components.

[0099] It should be noted that the high-pressure flushing valve 101 is designed specifically for the flushing work in the early stage of the hot functional test. After the flushing work for the hot functional test is completed, the high-pressure flushing valve 101 should be removed to avoid affecting the subsequent hot functional test. In addition, other temporary pipelines and temporary devices related to the flushing work should also be disassembled to avoid affecting the subsequent hot functional test.

[0100] In some embodiments, the deoxygenated water supply system 100 further includes an auxiliary steam system, which is connected to the feedwater deaerator 1. The main feedwater header is connected to the high-pressure feedwater system, and a second recirculation isolation valve is provided between the main feedwater header and the high-pressure feedwater system.

[0101] Please see Figure 7 Step S30 includes:

[0102] S31. Start the conventional island demineralized water distribution system 2. After the deoxygenated water supply system 100 has completed cleaning, the water quality in the deoxygenated water supply system 100 needs to be adjusted so that the water in the deoxygenated water supply system 100 can meet the requirements of the hot functional test. Therefore, the water quality needs to be adjusted first, and then the water with adjusted water quality is used to replace the residual water in the pipes. Therefore, the conventional island demineralized water distribution system 2 needs to be started to supply water first.

[0103] S32. Start the auxiliary steam system to input steam into the feedwater deaerator 1. After the conventional island demineralized water distribution system 2 is started to supply water, the auxiliary steam system needs to be started to input steam into the feedwater deaerator 1 for deoxygenation. After the feedwater deaerator 1 receives the steam from the auxiliary steam system, it outputs deoxygenated water to the deoxygenated water supply system 100.

[0104] S33. Add an acid-base regulator to the water storage chamber of the feedwater deaerator 1 to adjust the pH value of the deoxygenated water in the feedwater deaerator 1 to the preset pH range. Adding the acid-base regulator to the water storage chamber of the feedwater deaerator 1 adjusts the pH value of the deoxygenated water, thereby ensuring that the deoxygenated water meets the requirements of the hot functional test.

[0105] S34. Open the first feed water pump group 8, the pump group outlet bypass valve 10, and the second recirculation isolation valve. After opening the first feed water pump group 8, the pump group outlet bypass valve 10, and the second recirculation isolation valve, qualified deoxygenated water can be pumped into each pipeline through the first feed water pump group 8, thereby flushing out the water remaining in the pipeline after rinsing, and replacing the water in each pipeline with qualified deoxygenated water.

[0106] S35. Close the first water supply pump group 8 and open the second water supply pump group 9. After the water in the pipeline connected to the first water supply pump group 8 has been flushed and replaced, the first water supply pump group 8 can be closed first and the second water supply pump group 9 can be opened to flush the pipeline connected to the second water supply pump group 9 and replace the water in the pipeline connected to the second water supply pump group 9.

[0107] S36. Close the second feedwater pump group 9 and start the deaerator recirculation pump. Similarly, after the water in the pipeline connected to the second feedwater pump group 9 has been flushed and replaced, the second feedwater pump group 9 can be closed first, and the deaerator recirculation pump can be started to flush the pipeline connected to the deaerator recirculation pump and replace the water in the pipeline connected to the deaerator recirculation pump. It should be noted that the starting sequence of the first feedwater pump group 8, the second feedwater pump group 9, and the deaerator recirculation pump is not fixed and can be adjusted and selected according to actual usage requirements.

[0108] It should be noted that all pipelines need to be flushed and cleaned before adjusting the pH value of the deoxygenated water. During the flushing process, some temporary flushing valves and temporary flushing pipelines need to be installed. Therefore, the temporary flushing valves and temporary flushing pipelines should be removed before adjusting the pH value to avoid affecting the subsequent hot functional tests.

[0109] In some embodiments, the pH value is preset to a range of 8.8 to 10. In hot functional testing, the pH of the deoxygenated water is generally adjusted to be weakly alkaline. In this application, the pH value is preset to a range of 8.8 to 10. When the pH value of the deoxygenated water is within this range, the deoxygenated water can meet the requirements of hot functional testing. Furthermore, the hot functional testing effect is better when the pH value of the deoxygenated water is between 9.6 and 9.9.

[0110] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0111] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for supplying deoxygenated water for hot functional tests of the nuclear island in a nuclear power plant, characterized in that, The nuclear power plant includes a deoxygenated water supply system, which includes a connected feedwater deaerator and a high-pressure feedwater system. The deoxygenated water supply method includes: The conventional island demineralized water distribution system is adjusted to be the water supply source of the deoxygenated water supply system, so that the inlet pipe of the conventional island demineralized water distribution system is directly connected to the water supply deaerator of the deoxygenated water supply system. Start the conventional island demineralized water distribution system so that the water flowing out of the conventional island demineralized water distribution system can clean the pipes and components between the conventional island demineralized water distribution system and the high-pressure water supply system; Start the water deaerator and adjust the water quality of the water flowing from the conventional island demineralized water distribution system to the high-pressure water supply system; The step of adjusting the conventional island demineralized water distribution system to be the water supply source for the deoxygenated water supply system, so that the inlet pipes of the conventional island demineralized water distribution system and the deoxygenated water supply system are directly connected, specifically includes: The first water supply pipeline between the low-pressure feedwater heater and the feedwater deaerator is cut off, so that the first water supply pipeline has a first section with one end connected to the feedwater deaerator. The second water supply pipeline between the conventional island demineralized water distribution system and the water supply deaerator is disconnected, so that the second water supply pipeline has a second section with one end connected to the conventional island demineralized water distribution system; Connect the first segment and the second segment to connect the inlet pipe of the conventional island demineralized water distribution system and the deoxygenated water supply system to the water supply deaerator.

2. The deoxygenated water supply method for hot functional tests of the nuclear island in a nuclear power plant according to claim 1, characterized in that, The first water supply pipeline also has a third section with one end connected to the low-pressure water heater; the second water supply pipeline also has a fourth section with one end connected to the water deaerator; the deoxygenated water supply system also includes two sealing components; The step of adjusting the conventional island demineralized water distribution system to be the water supply source for the deoxygenated water supply system, so that the inlet pipes of the conventional island demineralized water distribution system and the deoxygenated water supply system are connected, further includes: The third segment and the fourth segment are respectively sealed by one of the sealing components.

3. The deoxygenated water supply method for hot functional tests of the nuclear island in a nuclear power plant according to claim 1, characterized in that, The deoxygenated water supply system includes a deaerator recirculation pump, a first water supply pump group, a second water supply pump group, and a sewage collection tank. One end of the deaerator recirculation pump, one end of the first water supply pump group, and one end of the second water supply pump group are connected in parallel to the water supply deaerator. The other end of the deaerator recirculation pump, the other end of the first water supply pump group, and the other end of the second water supply pump group are connected in parallel to the sewage collection tank. A first recirculation isolation valve and an atmospheric pressure flushing valve are provided on the first pipeline between the parallel connection point of one end of the deaerator recirculation pump, one end of the first water supply pump group, and one end of the second water supply pump group and the sewage collection tank. The step of activating the conventional island demineralized water distribution system so that the water flowing out of the conventional island demineralized water distribution system can clean the pipelines and components between the conventional island demineralized water distribution system and the high-pressure water supply system includes: Start the conventional island demineralized water distribution system and turn on the deaerator recirculation pump, the first recirculation isolation valve and the atmospheric pressure flushing valve; Turn off the deaerator recirculation pump and turn on the first feedwater pump group; The first water supply pump unit is shut down, and the second water supply pump unit is turned on.

4. The deoxygenated water supply method for hot functional tests of the nuclear island in a nuclear power plant according to claim 3, characterized in that, A pump group outlet bypass valve and a high-pressure flushing valve are provided on the second pipeline between one end of the first water supply pump group and one end of the second water supply pump group and the sewage collection tank; the deoxygenated water supply system also includes a high-pressure heater bypass and the main water supply header located between the pump group outlet bypass valve and the high-pressure flushing valve. After the step of shutting down the first water supply pump group and starting the second water supply pump group, the method further includes: Close the first recirculation isolation valve and the atmospheric pressure flushing valve, and open the pump set outlet bypass valve and the high pressure flushing valve; The second water supply pump unit is shut down, and the first water supply pump unit is turned on.

5. The deoxygenated water supply method for hot functional testing of the nuclear island in a nuclear power plant according to claim 4, characterized in that, The deoxygenated water supply system also includes multiple high-pressure heaters for heating the deoxygenated water flowing out of the feedwater deaerator; After shutting down the second water supply pump group and turning on the first water supply pump group, the deoxygenated water supply method further includes: Shut down the conventional island demineralized water distribution system and the first feedwater pump group, and open the manhole doors of the feedwater deaerator and each of the high-pressure heaters to remove foreign objects from the feedwater deaerator and each of the high-pressure heaters.

6. The deoxygenated water supply method for hot functional testing of the nuclear island in a nuclear power plant according to claim 4, characterized in that, The deoxygenated water supply system also includes an auxiliary steam system, which is connected to the feedwater deaerator; the main feedwater header is connected to the high-pressure feedwater system, and a second recirculation isolation valve is provided between the main feedwater header and the high-pressure feedwater system. The steps of starting the feedwater deaerator and adjusting the water quality flowing from the conventional island demineralized water distribution system to the high-pressure feedwater system include: Start the conventional island demineralized water distribution system; Start the auxiliary steam system to input steam into the feedwater deaerator; An acid-base regulator is added to the water storage chamber of the water deaerator to adjust the pH value of the deoxygenated water in the water deaerator to a preset pH range. Open the first water supply pump set, the pump set outlet bypass valve, and the second recirculation isolation valve; The first water supply pump group is shut down, and the second water supply pump group is turned on; Shut down the second water supply pump set and start the deaerator recirculation pump.

7. The deoxygenated water supply method for hot functional tests of the nuclear island in a nuclear power plant according to claim 6, characterized in that, The preset pH value range is 8.8 to 10.

8. A deoxygenated water supply system for hot functional testing of the nuclear island in a nuclear power plant, used to implement the deoxygenated water supply method for hot functional testing of the nuclear island in a nuclear power plant as described in any one of claims 1 to 7, characterized in that, The deoxygenated water supply system used in the nuclear island hot functional test of a nuclear power plant includes: A water deaerator, internally equipped with nozzles, includes a deaerator for deoxygenating the water sprayed from the nozzles to supply deoxygenated water to various pipelines and components of the deoxygenated water supply system; and A conventional island demineralized water distribution system is connected to the nozzles and is used to supply water to the feedwater deaerator. The nuclear power plant also includes a low-pressure feedwater heater; a first water supply pipeline is provided between the low-pressure feedwater heater and the feedwater deaerator, and the first water supply pipeline is disconnected so that the first water supply pipeline has a first section with one end connected to the feedwater deaerator and a third section with one end connected to the low-pressure feedwater heater. A second water supply pipeline is provided between the conventional island demineralized water distribution system and the feedwater deaerator. The second water supply pipeline is disconnected, so that the second water supply pipeline has a second section with one end connected to the conventional island demineralized water distribution system and a fourth section with one end connected to the feedwater deaerator; the first section is connected to the second section.

9. The deoxygenated water supply system for hot functional testing of the nuclear island in a nuclear power plant according to claim 8, characterized in that, The deoxygenated water supply system used in the nuclear island hot functional test of a nuclear power plant also includes two sealing components, which are used to seal the opening of the third section and the opening of the fourth section, respectively.

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