A renewable steam generator water source treatment system

Abstract

The application relates to a renewable steam generator water source treatment system, which comprises a first water source, a renewable heat exchange device, a buffer water tank, a first water supply pump, a first steam generator, a deoxygenation workstation, a second water supply pump and a second steam generator, a circulating loop is formed between the first water source and the deoxygenation workstation; the renewable heat exchange device is provided with a first heat exchange water inlet pipe, a second heat exchange water inlet pipe and a heat exchange water outlet pipe, the first heat exchange water inlet pipe is communicated with the deoxygenation workstation, the second heat exchange water inlet pipe is communicated with a first water source water outlet pipe; and the heat exchange water outlet pipe is respectively communicated with a water inlet of the buffer water tank and the first water supply pump. The renewable steam generator water source treatment system ensures the safety of a power plant and improves the economy of the power plant.

Description

Technical Field

[0001] This invention belongs to the field of nuclear plant technology, specifically relating to a water treatment system for a renewable steam generator. Background Technology

[0002] In nuclear engineering design, based on previous power plant designs, the dissolved oxygen content in the feedwater to the steam generator can cause corrosion to thermal equipment and pipelines. Therefore, during normal operation, the oxygen content of the feedwater is usually limited, and deoxygenation is performed on the feedwater. However, in some accident situations, deoxygenated feedwater is still supplied to the steam generator, directly limiting the water source capacity and which is detrimental to controlling the safety of the power plant.

[0003] During normal operation of the power plant, the steam generator relies on a single water source. If it is supplied solely by the secondary loop deaerator, its deaeration capacity is limited. Currently, the deaerators in the conventional island of the power plant primarily use physical deaeration methods, employing thermal deaeration. This requires the power plant to supply steam to the deaerator. However, during startup and shutdown, the secondary loop typically cannot supply steam, thus limiting the deaerator's supply capacity and potentially leading to a loss of feedwater. Furthermore, the steam generator's water supply pipes are subjected to alternating hot and cold water supply. The internal thermal stress caused by these temperature changes can cause micro-cracks to develop and propagate within the metal material, eventually leading to rupture. Therefore, this should be avoided as much as possible to extend the pipes' service life.

[0004] In previous engineering designs, to ensure that the steam generator supply water was demineralized and deoxygenated, large-sized storage tanks were typically designed, resulting in a large footprint. In addition, water tanks with floating roof seals have particularly poor sealing performance and extremely high reoxygenation rates; sealed water tanks made of stainless steel with breather valves are prone to negative pressure deformation and damage. Summary of the Invention

[0005] In view of the deficiencies in the existing technology, the purpose of this invention is to provide a renewable steam generator water treatment system to improve water supply capacity and avoid corrosion of thermal equipment and pipelines caused by dissolved oxygen content in the feed water, thereby extending the service life of the pipelines.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a regenerative steam generator water source treatment system, comprising a first water source, a regenerative heat exchange device, a buffer water tank, a first water supply pump, a first steam generator, a deaeration station, a second water supply pump, and a second steam generator. The first water source is equipped with a first water source outlet pipe and a first water source inlet pipe, which are respectively connected to the deaeration station to form a circulation loop between the first water source and the deaeration station. The regenerative heat exchange device is equipped with a first heat exchange inlet pipe, a second heat exchange inlet pipe, and a heat exchange outlet pipe. The first heat exchange inlet pipe is connected to the deaeration station, and the second heat exchange inlet pipe is connected to the first water source outlet pipe. The heat exchange outlet pipe is respectively connected to the inlet of the buffer water tank and the first water supply pump. The first water supply pump is connected to the first steam generator, and the second water supply pump is connected to... The buffer water tank outlet and the second steam generator are connected separately. The buffer water tank inlet and outlet are respectively connected to the deaeration station outlet and inlet. An inlet isolation valve is provided between the first water source outlet pipe and the deaeration station, and an outlet isolation valve is provided between the first water source inlet pipe and the deaeration station. A first heat exchange inlet isolation valve is provided on the first heat exchange inlet pipe, and a second heat exchange inlet isolation valve is provided on the second heat exchange inlet pipe. A first buffer inlet isolation valve and a first supply isolation valve are provided between the heat exchange outlet pipe, the buffer water tank inlet, and the first water supply pump. A second supply isolation valve is provided between the buffer water tank outlet and the second water supply pump. A circulation isolation valve is also provided between the buffer water tank outlet and the deaeration station. A second buffer inlet isolation valve is provided between the buffer water tank inlet and the deaeration station outlet.

[0007] Furthermore, a first circulation pump is installed between the first water source and the deoxygenation station, and the first circulation pump is connected to the water inlet pipe of the first water source.

[0008] Furthermore, a second circulation pump is installed between the outlet of the buffer water tank and the inlet of the deoxygenation station.

[0009] Furthermore, the renewable steam generator water treatment system also includes a second water source, the inlet of which is connected to the outlet of the first water source, and the outlet of which is connected to the inlet of the renewable heat exchange device; wherein, a first water replenishment isolation valve is provided between the inlet of the second water source and the outlet of the first water source 1, and a second water replenishment isolation valve is provided between the outlet of the second water source 2 and the inlet of the renewable heat exchange device.

[0010] Furthermore, a water replenishment pump is installed between the second water source and the first water source.

[0011] Furthermore, the deaeration workstation is equipped with external deaeration pipelines at its inlet and outlet.

[0012] Furthermore, a bypass pipeline is provided at the inlet and outlet of the regenerative heat exchange device, and a bypass isolation valve is provided on the bypass pipeline.

[0013] Furthermore, two connecting pipelines are respectively installed at the inlet and outlet of the first water supply pump and the second water supply pump, and a connecting isolation valve is installed on each of the two connecting pipelines.

[0014] Furthermore, regulating valves are provided between the first water supply pump and the first steam generator, and between the second water supply pump and the second steam generator, to regulate the flow rate of water entering the first steam generator and the second steam generator.

[0015] Furthermore, a steam isolation valve is provided between the first water supply pump and the first steam generator, and between the second water supply pump and the second steam generator; a check valve is provided between the first water supply pump and the first steam generator, and between the second water supply pump and the second steam generator; the first steam generator and the second steam generator are both located inside the nuclear island building, and the first water supply pump and the second water supply pump are respectively connected to the first steam generator and the second steam generator by passing through the containment penetration through pipelines.

[0016] The advantages of this invention are as follows: regardless of the operating conditions of the power plant, the system ensures the water supply to the steam generator and the necessary isolation valves by adopting diversified water source configurations, modular and multi-combination structures of the deaeration workstation, multi-user modular and multi-combination structures of the regenerable heat exchange device, small and well-sealed buffer water tanks, and reliable isolation measures, thereby ensuring the safety of the power plant and improving its economic efficiency. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the framework of a renewable steam generator water treatment system in this invention;

[0018] Figure 2 yes Figure 1 A schematic diagram of the modules of the renewable heat exchanger.

[0019] Figure 3 yes Figure 1 A schematic diagram of the deoxygenation workstation modules.

[0020] Explanation of reference numerals in the attached figures:

[0021] 1. Primary water source; 2. Secondary water source; 3. Renewable heat exchanger; 4. Buffer tank; 5. Primary water supply pump; 6. Primary steam generator; 7. Deaeration station; 8. Secondary water supply pump; 9. Secondary steam generator; 17. Primary water source outlet pipe; 18. Primary water source inlet pipe; 19. Primary heat exchanger inlet pipe; 20. Secondary heat exchanger inlet pipe; 21. Heat exchanger outlet pipe; 22. Connecting pipeline; 25. Bypass pipeline; 26. External deaeration pipeline; 31. Primary water supply isolation valve; 32. Secondary water supply isolation valve. 33. Water isolation valve; 34. Inlet isolation valve; 35. Outlet isolation valve; 36. First heat exchanger inlet water isolation valve; 47. Second heat exchanger inlet water isolation valve; 48. First buffer inlet water isolation valve; 49. Circulation isolation valve; 50. Second buffer inlet water isolation valve; 51. Regulating valve; 52. Steam isolation valve; 53. Check valve; 54. Bypass isolation valve; 55. Connecting isolation valve; 66. Makeup water pump; 67. First circulation pump; 68. Second circulation pump. Detailed Implementation

[0022] The present invention will now be further described with reference to the accompanying drawings and specific embodiments.

[0023] like Figure 1-3 As shown, the present invention provides a water treatment system for a regenerative steam generator, comprising a first water source 1, a regenerative heat exchange device 3, a buffer tank 4, a first water supply pump 5, a first steam generator 6, a deaeration station 7, a second water supply pump 8, and a second steam generator 9. The first water source 1 is equipped with a first water source outlet pipe 17 and a first water source inlet pipe 18, which are respectively connected to the deaeration station 7 to form a circulation loop between the first water source 1 and the deaeration station 7. The regenerative heat exchange device 3 is equipped with a first heat exchange inlet pipe 19, a second heat exchange inlet pipe 20, and a heat exchange outlet pipe 21. The first heat exchange inlet pipe 19 is connected to the deaeration station 7, and the second heat exchange inlet pipe 20 is connected to the first water source outlet pipe 17. The heat exchange outlet pipe 21 is connected to the inlet of the buffer water tank 4 and the first water supply pump 5, respectively. The first water supply pump 5 is connected to the first steam generator 6. The second water supply pump 8 is connected to the outlet of the buffer water tank 4 and the second steam generator 9, respectively. The inlet and outlet of the buffer water tank 4 are connected to the outlet and inlet of the deaeration station 7, respectively.

[0024] Among them, an inlet isolation valve 33 is installed between the first water source outlet pipe 17 and the deoxygenation station 7; an outlet isolation valve 34 is installed between the first water source inlet 18 and the deoxygenation station 7; a first heat exchange inlet water valve 35 is installed on the first heat exchange inlet water pipe 19; a second heat exchange inlet water valve 36 is installed on the second heat exchange inlet water pipe 20; a first buffer inlet water valve 43 and a first supply water valve 48 are installed between the heat exchange outlet water pipe 21, the inlet of the buffer water tank 4, and the first water supply pump 5; a second supply water valve 44 is installed between the outlet of the buffer water tank 4 and the second water supply pump 8; a circulation isolation valve 45 is also installed between the outlet of the buffer water tank 4 and the deoxygenation station 7; and a second buffer inlet water valve 46 is installed between the inlet of the buffer water tank 4 and the outlet of the deoxygenation station 7.

[0025] It is understood that by opening or closing the above-mentioned isolation valves, the direction of water flow in the first water source 1 in the water source treatment system of the regenerable steam generator can be controlled, thereby making adjustments according to the actual situation.

[0026] To illustrate with a specific example, when a high degree of deoxygenation is required for the influent, the first heat exchange influent isolation valve 35 and the second heat exchange influent isolation valve 36 can be closed first, and the inlet isolation valve 33 can be opened to allow the water in the first water source 1 to circulate and deoxygenate through the deoxygenation station 7 until the required degree of deoxygenation is achieved. Then, the inlet isolation valve 33 is closed to interrupt the circulation, and the second heat exchange influent isolation valve 36 is opened to allow the deoxygenated water to enter the regenerative heat exchange device 3. If the deoxygenation requirement can be met by the water in the first water source 1 after one deoxygenation process through the deoxygenation station 7, then the first heat exchange influent isolation valve 35 can be opened, and the second heat exchange influent isolation valve 36 and the outlet isolation valve 34 of the deoxygenation station 7 can be closed to allow the deoxygenated water to enter the regenerative heat exchange device 3.

[0027] After the water flows out of the regenerative heat exchanger 3, when the first water supply isolation valve 48 is opened and the first buffer inlet water isolation valve 43 is closed, the water flows directly into the first steam generator 6 through the first water supply pump 5. When the first water supply isolation valve 48 is closed and the first buffer inlet water isolation valve 43 is opened, the water flows into the buffer water tank 4, and through the opening or closing of the first water supply isolation valve 44 and the circulation isolation valve 45, the water flowing out of the buffer water tank 4 enters the second steam generator 9 through the second water supply pump 8, or re-enters the deaeration station 7 for deaeration.

[0028] It is understandable that by setting up a buffer water tank 4, the water storage function of the buffer water tank 4 can be used to protect the first water supply pump 5 and the second water supply pump 8. When the deoxygenation requirement is high, the water in the buffer water tank 4 can also be circulated and re-enter the deoxygenation workstation 7 for deoxygenation.

[0029] Furthermore, a first circulation pump 62 is installed between the first water source 1 and the deoxygenation station 7. The first circulation pump 62 is connected to the first water source inlet pipe 18 so that the water can flow in the circulation loop through the first circulation pump 62.

[0030] Furthermore, a second circulation pump 63 is installed between the outlet of the buffer water tank 4 and the inlet of the deaeration station 7, so that the water in the buffer water tank 4 can be re-entered into the deaeration station 7.

[0031] Furthermore, the water treatment system for the renewable steam generator also includes a second water source 2, the inlet of which is connected to the outlet of the first water source 1, and the outlet of which is connected to the inlet of the renewable heat exchange device 3.

[0032] A first water replenishment isolation valve 31 is provided between the inlet of the second water source 2 and the outlet of the first water source 1, and a second water replenishment isolation valve 32 is provided between the outlet of the second water source 2 and the inlet of the regenerative heat exchange device 3.

[0033] Furthermore, a water replenishment pump 61 is installed between the second water source 2 and the first water source 1 to pump water from the first water source 1 into the second water source 2.

[0034] It is understandable that the first water source 1 is mainly low-temperature demineralized water, with a temperature below 50°C, located in the demineralized water tank within the plant area; the second water source 2 is mainly demineralized and deoxygenated water at around 150°C, located in the deoxygenated water tank of the secondary loop in the conventional island. While the two water sources differ in temperature and oxygen content, different water sources can be used under different operating conditions based on the actual availability of the nuclear power plant. For example, when the power plant is under certain operating conditions and the deoxygenated water source 2 itself is insufficient or unavailable, the first water source 1 can be used for water supply. Under normal circumstances, demineralized and deoxygenated water is used to supply water to the steam generator. In the event of a severe accident, demineralized water can also be used directly for supply. Furthermore, demineralized water from the first water source 1 can be supplied to the second water source 2 via a makeup water pump, and then deoxygenated by the built-in deoxygenation system in the second water source 2 before supplying water. This configuration, employing diverse water sources, enhances the nuclear power plant's defense-in-depth capability.

[0035] It is understood that, in some embodiments, the second water source 2 may be equipped with its own deoxygenation equipment to deoxygenate the water therein.

[0036] Furthermore, external deoxygenation pipelines 26 are installed at the inlet and outlet of the deoxygenation station 7, so that other users can also use the deoxygenation station through the external deoxygenation pipelines.

[0037] Furthermore, a bypass pipeline 25 is provided at the inlet and outlet of the regenerative heat exchanger 3, and a bypass isolation valve 53 is provided on the bypass pipeline 25. By providing the bypass pipeline 25, water can flow directly through the bypass pipeline 25 without passing through the regenerative heat exchanger 3.

[0038] Furthermore, two connecting pipelines 22 are respectively installed at the inlet and outlet of the first water supply pump 5 and the second water supply pump 8. Both connecting pipelines 22 are equipped with connecting isolation valves 56. By setting up two connecting pipelines, the first water supply pump 5 and the second water supply pump 8 can be used interchangeably with the first steam generator 6 and the second steam generator 9, respectively.

[0039] Furthermore, regulating valves 49 are provided between the first water supply pump 5 and the first steam generator 6, and between the second water supply pump 8 and the second steam generator 9, to regulate the flow rate of water entering the first steam generator 6 and the second steam generator 9.

[0040] Furthermore, a steam isolation valve 50 is provided between the first water supply pump 5 and the first steam generator 6, and between the second water supply pump 8 and the second steam generator 9.

[0041] Furthermore, a check valve 51 is provided between the first water supply pump 5 and the first steam generator 6, and between the second water supply pump 8 and the second steam generator 9.

[0042] Furthermore, both the first steam generator 6 and the second steam generator 9 are located inside the nuclear island building. The first water supply pump 5 and the second water supply pump 8 are connected to the first steam generator 6 and the second steam generator 9 by passing through the containment penetration through pipelines.

[0043] Furthermore, the renewable heat exchange device 3 includes at least one heat exchange user.

[0044] It is understandable that when there are multiple heat exchange users, these users can be combined in any way, such as series, parallel, or a combination of series and parallel connections, according to actual needs.

[0045] Furthermore, the deoxygenation workstation 7 includes at least one deoxygenation module.

[0046] It is understandable that when there are multiple deoxygenation modules, they can be combined in any way, such as in series, parallel, or series-parallel connection, according to the deoxygenation requirements.

[0047] In this embodiment, under normal operating conditions of the nuclear power plant, when the secondary loop deaerator located in the conventional island is available, the water source for supplying water to the steam generator can be the second water source 2, ensuring the supply of desalination and deoxygenation water. If the water volume of the second water source 2 is insufficient during use, the first water source 1 can replenish water to the second water source 2 through a connecting pipeline. At this time, the normally closed first water replenishment isolation valve 31 on the connecting pipeline is opened, and the water replenishment pump 61 is started. The second water source 2 can enter the regenerative heat exchanger 3 through the connecting pipeline, and be used to cool the water for suitable users. If there are no users requiring cooling, the water source 2 can bypass the regenerative heat exchanger 3, directly enter the inlet of the water supply pump, then enter the nuclear island building, and finally enter the steam generator.

[0048] Under normal operating conditions of a nuclear power plant, when the secondary loop deaerator located in the conventional island is unavailable, the water source supplying the steam generator can be the first water source 1. The first water source 1 contains low-temperature subcooled water that has been desalinated but not deoxygenated. The first water source 1 can be connected to either the deaeration station 7 or directly to the regenerative heat exchanger 3 via connecting pipelines. If the first water source 1 is used entirely to supply water to the steam generator, it can be directly connected to the deaeration station 7, where one or more deaeration modules can be selected to achieve rapid, high-flow-rate deaeration. Once the first water source 1 meets the desalination and deaeration requirements, it enters the regenerative heat exchanger 3 and is then used to cool the water for appropriate users. If there are no users requiring deaeration, the water can bypass the regenerative heat exchanger 3 and flow directly into the inlet of the water supply pump, then into the nuclear island building, and finally into the steam generator.

[0049] Under normal operating conditions of a nuclear power plant, when the secondary loop deaerator located in the conventional island is unavailable, the water source for supplying water to the steam generator can be the first water source 1. The first water source 1 contains low-temperature subcooled water that has been desalinated but not deoxygenated. The first water source 1 can be connected to either the deaeration station 7 or directly to the regenerative heat exchanger 3 via connecting pipelines. If the first water source 1 is not entirely used to supply water to the steam generator and has many water users, it can be preliminarily deoxygenated by the deaeration station 7 before entering the regenerative heat exchanger 3. Alternatively, the first water source 1 can bypass the deaeration station 7 and directly enter the regenerative heat exchanger 3, selectively cooling suitable users. If there are no users requiring cooling, the regenerative heat exchanger 3 can be bypassed, and the water can directly enter the buffer tank 4. In this case, the first water supply isolation valve 48 on the connecting pipeline from the outlet pipeline of the regenerative heat exchanger 3 to the water supply pump is closed. The water that has been initially desalinated and deoxygenated in the buffer water tank 4 needs to be pumped into the deoxygenation station 7 for strict deoxygenation. One or more deoxygenation modules are selected in the deoxygenation station 7 to achieve rapid and high-flow-rate deoxygenation. The water is then returned to the buffer water tank 4 until the first water source 1 meets the requirements for desalination and deoxygenation. Then the water enters the nuclear island plant and finally enters the steam generator.

[0050] In the event of an accident at the nuclear power plant, if the second water source 2 is available, in addition to supplying water to the steam generator according to the aforementioned supply process under normal nuclear power plant conditions, in an emergency, the second water source 2 can directly bypass the regenerative heat exchanger 3 to supply water directly to the water supply pump, thereby meeting the requirements of the steam generator. If the second water source 2 is unavailable, the first water source 1 can be used. Besides supplying water to the steam generator according to the aforementioned supply process under normal nuclear power plant conditions, in an emergency, the first water source 1 can bypass deoxygenation, directly bypass the regenerative heat exchanger 3, and bypass the buffer tank 4 to supply water directly to the water supply pump, thereby meeting the requirements of the steam generator.

[0051] In this embodiment, check valve 51 is used to prevent radioactivity inside the containment from being released outside the containment through the pipeline in the event of a rupture. Regulating valve 49 is used to regulate the feedwater flow rate into the steam generator.

[0052] In the event of a failure in the feedwater system, steam generator, or steam side, regulating valve 49 and steam isolation valve 50 are used to quickly isolate the feedwater, preventing further feedwater loss, preventing the release of more mass energy into the containment, preventing steam generator overflow, or preventing excessive feedwater flow leading to overcooling of the reactor coolant system, etc. Regulating valve 49 has both regulating and rapid isolation functions. Effective feedwater isolation is achieved through two diverse valves, reducing common causes of valve closure failures. Furthermore, from a deterministic perspective, even if one valve is lost, there is still a usable valve for isolation, thus improving isolation reliability.

[0053] It's understandable that the deoxygenation modules in Deoxygenation Station 7 were determined based on a comprehensive analysis of the nuclear power plant, including which modules use which deoxygenation methods, which modules are connected in parallel, and which modules are designed in series. For example, if time is of the essence, deoxygenation can be completed in one go through the combination of deoxygenation modules and flow rate adjustment, allowing for a stable water supply downstream. If time is not of the essence, from the perspective of improving the utilization rate of deoxygenation modules and the economic efficiency of the power plant, fewer modules and conventional flow rates can be selected to perform multiple continuous deoxygenation cycles to meet the oxygen content requirements of the water supplied to the steam generator.

[0054] It is understandable that the regenerative heat exchanger 3 was designed with potential users in mind from the initial stages. Depending on user needs, parallel, series, or combined series-parallel structures were implemented. The aim is to meet the cooling requirements of each user while maximizing the optimal use of the regenerative heat exchanger 3. This allows it to both cool users and recover some heat, appropriately increasing the feedwater temperature and preventing thermal fatigue issues in the steam generator and its feedwater delivery pipelines under alternating feedwater supply with large temperature differences.

[0055] As can be seen from the above embodiments, regardless of the operating conditions of the power plant, the system in this invention ensures the water supply to the steam generator and the necessary isolation valves, thereby guaranteeing the safety of the power plant and improving its economic efficiency, by adopting diversified water source configurations, modular and multi-combination structures of the deaeration workstation 7, multi-user modular and multi-combination structures of the regenerable heat exchange device 3, small and well-sealed buffer water tank 4, and reliable isolation measures.

[0056] The specific effects are as follows: (1) The steam generator in this system has two water sources, namely the first water source 1 and the second water source 2. The first water source 1 is mainly low-temperature demineralized water with a temperature of less than 50°C, located in the demineralized water tank in the plant area; the second water source 2 is mainly demineralized and deoxygenated water with a temperature of around 150°C, located in the deoxygenated water tank of the secondary loop in the conventional island; the two water sources have differences in temperature and oxygen content, but different water sources can be used under different operating conditions according to the actual availability of the nuclear power plant. For example, when the power plant is under certain operating conditions, if the deoxygenated water source of the second water source 2 is insufficient or unavailable, the first water source 1 can be used for water supply. Under normal circumstances, demineralized and deoxygenated water is used to supply water to the steam generator. In the event of a serious accident, demineralized water can also be used directly for supply. In addition, the demineralized water in the first water source 1 can also be supplied to the second water source 2 through the water supply pump 61, and then deoxygenated by the self-contained deoxygenation system in the second water source 2 before water supply. The use of diversified water sources in this configuration enhances the nuclear power plant's defense-in-depth function.

[0057] (2) Water source 1 and water source 2 are two types of undersaturated water at different temperatures. Besides supplying water to the steam generator, they can also be used for cooling high-temperature media in the power plant, subject to water temperature limits. Various connection methods are employed based on the different high-temperature media heat exchange users. Heat exchange users can be connected in series, in parallel, or in a combination of series and parallel configurations. Each user is equipped with a regulating valve and an isolation valve for operation and isolation. Bypassing heat exchange users is also possible as needed. These flexible combinations meet different requirements, such as reducing the temperature of the steam generator's wastewater or the temperature of the high-temperature sampling cooler. Furthermore, in certain situations, when cooling heat exchange users, the supply temperature of water source 1 can be appropriately increased to avoid a large temperature difference between water source 1 and water source 2, which could cause thermal stress fatigue damage to the steam generator's water supply pipe. Cooling and heat recovery are both concentrated in the regenerative heat exchanger 3. After the system removes the user's heat, it can continue to supply water to the steam generator. In some cases, it can also prevent the steam generator water supply pipe from experiencing thermal fatigue under alternating hot and cold conditions, which would lead to a decrease in performance.

[0058] (3) The system includes a deoxygenation station 7 for deoxygenating the demineralized water. This deoxygenation station is modularly configured, with modules tailored to the required deoxygenation volume and the circulating water tank. These deoxygenation modules can be connected in series, in parallel, or in a combination of both. Each deoxygenation module can be a single or combined form of thermal deoxygenation, ion deoxygenation, or catalytic deoxygenation, with the optimal combination selected. The first water source 1 is demineralized water. If deoxygenation is not required, it can directly enter the regenerable heat exchanger 3, or bypass the regenerable heat exchanger 3 to enter the water supply pump or buffer tank 4. If the first water source 1 requires deoxygenation before supplying, it must first be deoxygenated by the deoxygenation station 7 before being supplied downstream. If one deoxygenation step is insufficient, it can return to the first water source 1 for circulating deoxygenation until the requirements are met. Furthermore, this deoxygenation station can also perform circulating deoxygenation on the buffer tank 4. This deoxygenation station adopts a modular, centralized design, with different modules capable of using different deoxygenation methods. Modules can also be connected in series or parallel. Each module is equipped with regulating valves and isolation valves for commissioning and isolation, resulting in diversified, optimized, and centralized deoxygenation methods. From the water source to the deoxygenation station, then to the regenerative heat exchanger 3, then to the buffer tank 4, and finally to the water supply pump inlet, different water supply paths can be selected according to the actual operating conditions of the power plant, ensuring the fastest and most optimal water supply and better serving the power plant.

[0059] (4) The supply water from the regenerable heat exchanger 3 may be desalinated and deoxygenated water, or it may be demineralized water. The choice between directing it to the water supply pump or to the buffer tank 4 depends on the actual operating needs of the power plant. For demineralized water requiring further deoxygenation, it can enter the buffer tank 4. The buffer tank 4 only serves as a temporary storage unit, facilitating flexible use by the power plant and ensuring a stable and reliable water supply. In case of accidental reoxygenation in the buffer tank 4, rapid circulation deoxygenation can be achieved through the deoxygenation station 7. The buffer tank 4 can adopt a floating roof isolation design, making it easier to ensure the airtightness of the isolation and preventing reoxygenation. Furthermore, the buffer tank 4 has a small footprint and flexible layout.

[0060] (5) Connecting pipelines 22 are installed on both the inlet and outlet pipelines of the water supply pump, and normally closed connecting isolation valves 56 are installed to ensure the selectivity of the pump inlet water source and the flexibility of the pump outlet supply pipeline in case of an accident. At the same time, the arrangement height of the first water source 1, the second water source 2, and the buffer tank 4, which can directly supply water to the water supply pump, should take into account the minimum height difference required by the net positive suction head of the water supply pump under the most unfavorable conditions, thereby improving the reliability of the power plant's water supply. In addition, regulating valves 49, steam isolation valves 50, and check valves 51 are installed on the water supply pipelines. Among them, regulating valve 49 has an isolation function, which is equivalent to the water supply having two isolation functions, ensuring the reliability of water supply isolation, and further ensuring the steam generator's anti-overflow function.

[0061] The device described in this invention is not limited to the embodiments described in the specific implementation. Other implementation methods derived by those skilled in the art based on the technical solution of this invention also fall within the scope of technical innovation of this invention.

Claims

1. A water treatment system for a renewable steam generator, characterized in that, include: The system comprises a first water source (1), a regenerative heat exchange device (3), a buffer water tank (4), a first water supply pump (5), a first steam generator (6), a deoxygenation station (7), a second water supply pump (8), and a second steam generator (9). The first water source (1) is equipped with a first water source outlet pipe (17) and a first water source inlet pipe (18). The first water source outlet pipe (17) and the first water source inlet pipe (18) are respectively connected to the deoxygenation station (7) so that a circulation loop is formed between the first water source (1) and the deoxygenation station (7). The regenerative heat exchange device (3) is equipped with a first heat exchange inlet pipe (19) and a second heat exchange inlet pipe (19). The first heat exchange inlet pipe (19) is connected to the deaeration station (7), and the second heat exchange inlet pipe (20) is connected to the first water source outlet pipe (17). The heat exchange outlet pipe (21) is connected to the inlet of the buffer tank (4) and the first water supply pump (5). The first water supply pump (5) is connected to the first steam generator (6). The second water supply pump (8) is connected to the outlet of the buffer tank (4) and the second steam generator (9). The inlet and outlet of the buffer tank (4) are connected to the outlet and inlet of the deaeration station (7). Among them, an inlet isolation valve (33) is provided between the first water source outlet pipe (17) and the deoxygenation station (7), an outlet isolation valve (34) is provided between the first water source inlet pipe (18) and the deoxygenation station (7), a first heat exchange inlet isolation valve (35) is provided on the first heat exchange inlet pipe (19), a second heat exchange inlet isolation valve (36) is provided on the second heat exchange inlet pipe (20), and the heat exchange outlet pipe (21) is connected to the inlet of the buffer water tank (4) and the... A first buffer inlet isolation valve (43) and a first supply isolation valve (48) are respectively provided between the first water supply pump (5). A second supply isolation valve (44) is provided between the outlet of the buffer water tank (4) and the second water supply pump (8). A circulation isolation valve (45) is also provided between the outlet of the buffer water tank (4) and the deaeration station (7). A second buffer inlet isolation valve (46) is provided between the inlet of the buffer water tank (4) and the outlet of the deaeration station (7). Two connecting pipelines (22) are respectively provided at the inlet and outlet of the first water supply pump (5) and the second water supply pump (8), and a connecting isolation valve (56) is provided on both connecting pipelines (22); The renewable steam generator water treatment system also includes a second water source (2), the inlet of the second water source (2) is connected to the outlet of the first water source (1), and the outlet of the second water source (2) is connected to the inlet of the renewable heat exchange device (3). Among them, a first water replenishment isolation valve (31) is provided between the inlet of the second water source (2) and the outlet of the first water source (1), and a second water replenishment isolation valve (32) is provided between the outlet of the second water source (2) and the inlet of the regenerative heat exchange device (3). A water supply pump (61) is provided between the second water source (2) and the first water source (1).

2. The renewable steam generator water treatment system as described in claim 1, characterized in that: A first circulation pump (62) is provided between the first water source (1) and the deoxygenation station (7), and the first circulation pump (62) is connected to the first water source inlet pipe (18).

3. The renewable steam generator water treatment system as described in claim 1, characterized in that: A second circulation pump (63) is installed between the outlet of the buffer water tank (4) and the inlet of the deoxygenation station (7).

4. The renewable steam generator water treatment system as described in claim 1, characterized in that: The deoxygenation workstation (7) is equipped with external deoxygenation pipelines (26) at its inlet and outlet.

5. A renewable steam generator water treatment system as described in claim 1, characterized in that: The regenerative heat exchanger (3) is provided with a bypass pipeline (25) at its inlet and outlet, and a bypass isolation valve (53) is provided on the bypass pipeline (25).

6. The water treatment system for a renewable steam generator as described in claim 1, characterized in that: A regulating valve (49) is provided between the first water supply pump (5) and the first steam generator (6), and between the second water supply pump (8) and the second steam generator (9), to regulate the flow rate of water entering the first steam generator (6) and the second steam generator (9).

7. A renewable steam generator water treatment system as described in claim 1, characterized in that: A steam isolation valve (50) is provided between the first water supply pump (5) and the first steam generator (6) and between the second water supply pump (8) and the second steam generator (9); A check valve (51) is provided between the first water supply pump (5) and the first steam generator (6), and between the second water supply pump (8) and the second steam generator (9); The first steam generator (6) and the second steam generator (9) are both located inside the nuclear island building. The first water supply pump (5) and the second water supply pump (8) are respectively connected to the first steam generator (6) and the second steam generator (9) through pipelines through the containment penetration.

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