A method for preparing demineralized water in a high-temperature gas-cooled reactor

Abstract

The present invention provides a method for preparing demineralized water in a high-temperature gas-cooled reactor, which includes opening the manual flushing and draining valve, and the raw water in the clear water tank circulates into the clear water tank; closing the recirculation valve interlocked according to the outlet signal of the clear water pump, and opening the electric flushing and draining valve; starting the first high-pressure pump; the preliminarily filtered water output by the activated carbon filter is mixed with the scale inhibitor output by the dosing system and then enters the first-stage reverse osmosis device; the first-stage demineralized water output by the first-stage reverse osmosis device enters the first-stage fresh water tank; when the liquid level of the first-stage fresh water tank reaches the first preset liquid level, start the second high-pressure pump and the first-stage fresh water pump; when the liquid level of the second-stage fresh water tank reaches the second preset liquid level, start the second-stage fresh water pump, and the second-stage demineralized water in the second-stage fresh water tank enters the EDI desalination device through the second-stage fresh water pump. One technical effect of the present invention is that the design is reasonable, the overall logic of the operation of the first-stage reverse osmosis device is improved, the raw water pretreatment system is optimized, and the stability of the operation of the raw water pretreatment system is ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of high-temperature gas-cooled reactors, and particularly relates to a method for preparing demineralized water for a high-temperature gas-cooled reactor. Background Art

[0002] In the demineralized water treatment system of the high-temperature gas-cooled reactor demonstration project, there are three-stage desalination devices (a first-stage reverse osmosis device, a second-stage reverse osmosis device, and an EDI desalination device), which are used to produce high-purity demineralized water meeting the nuclear power plant standards for supply to the nuclear island, conventional island, and auxiliary systems.

[0003] At present, the raw water pretreatment system of the high-temperature gas-cooled reactor is equipped with a fine sand filter and an activated carbon filter. A booster pump is provided between the activated carbon filter and the first-stage reverse osmosis device, and there is no intermediate water tank and intermediate water pump. Two-stage fresh water tanks and supporting pump sets are provided between the first-stage reverse osmosis, second-stage reverse osmosis, and EDI devices.

[0004] However, since a buffer intermediate water tank and an intermediate water pump need to be provided between the activated carbon filter and the first-stage reverse osmosis device, and the first-stage reverse osmosis device is put into operation and stopped by manually opening and closing the flushing and sewage discharge manual valve, otherwise, the first-stage reverse osmosis device cannot meet the design requirements of sequential control for start-up and shutdown. Moreover, when manually starting the first-stage reverse osmosis device, there is a great uncertainty in the manual control valve opening and closing speed. When the flushing and sewage discharge manual valve is closed too slowly, the high-pressure pump inlet pressure is too low and the pump trips; when the flushing and sewage discharge manual valve is closed too quickly, the overpressure protection of the raw water pretreatment system acts, and the container manhole seal is easily damaged.

[0005] Therefore, the efficiency of preparing demineralized water in the current raw water pretreatment system of the high-temperature gas-cooled reactor is extremely low, often triggering the high-pressure pump to trip, resulting in the system being unable to be put into operation in time, and the system operation stability is not good. The insufficient supply of demineralized water affects the stable production of the nuclear power plant. Summary of the Invention

[0006] The present invention aims to at least solve one of the technical problems existing in the prior art, and provides a new technical solution for a method for preparing demineralized water for a high-temperature gas-cooled reactor.

[0007] According to a first aspect of the present invention, there is provided a method for preparing demineralized water for a high-temperature gas-cooled reactor, including:

[0008] Step S101, put into operation the raw water pretreatment system, open the flushing and sewage discharge manual valve, and the raw water in the clear water tank circulates into the clear water tank through the recirculation pipeline under the action of the clear water pump;

[0009] Step S102: Interlock and close the recirculation valve on the recirculation pipeline according to the outlet signal of the clean water pump, and open the flushing and sewage draining electric valve. The raw water in the clean water tank sequentially passes through the clean water pump, fine sand filter, activated carbon filter, flushing and sewage draining manual valve, and flushing and sewage draining electric valve and enters the sewage collection unit for the first flushing and drainage.

[0010] Step S103: Take a sample and analyze the first flushing and drainage. After the water quality is qualified, put the dosing system into operation.

[0011] Step S104: Start the first high-pressure pump and synchronously close the flushing and sewage draining electric valve. The preliminarily filtered water output by the activated carbon filter is mixed with the scale inhibitor output by the dosing system and then enters the first-stage reverse osmosis device through the first high-pressure pump for the second flushing and drainage.

[0012] Step S105: Take a sample and analyze the second flushing and drainage. After the water quality is qualified, the first-stage desalted water output by the first-stage reverse osmosis device enters the first-stage fresh water tank. When the liquid level of the first-stage fresh water tank reaches the first preset liquid level, start the second high-pressure pump and the first-stage fresh water pump. The first-stage desalted water in the first-stage fresh water tank sequentially passes through the first-stage fresh water pump and the second high-pressure pump and enters the second-stage reverse osmosis device for the third flushing and drainage.

[0013] Step S106: Take a sample and analyze the third flushing and drainage. After the water quality is qualified, the second-stage desalted water output by the second-stage reverse osmosis device enters the second-stage fresh water tank. When the liquid level of the second-stage fresh water tank reaches the second preset liquid level, start the second-stage fresh water pump. The second-stage desalted water in the second-stage fresh water tank passes through the second-stage fresh water pump and enters the EDI desalination device, and the EDI desalination device outputs desalted water that meets the requirements.

[0014] Optionally, the method for preparing desalted water for a high-temperature gas-cooled reactor further includes:

[0015] Step S201: Stop the raw water pretreatment system, stop the EDI desalination device, close the second-stage fresh water pump, and open the drainage valve of the second-stage reverse osmosis device.

[0016] Step S202: Stop the second-stage reverse osmosis device, close the second high-pressure pump and the first-stage fresh water pump, and open the drainage valve of the first-stage reverse osmosis device.

[0017] Step S203: Stop the first-stage reverse osmosis device, close the first high-pressure pump, and open the flushing and sewage draining pneumatic valve.

[0018] Step S204: Stop the fine sand filter and the activated carbon filter, open the recirculation valve on the recirculation pipeline, and the raw water in the clean water tank circulates into the clean water tank through the recirculation pipeline under the action of the clean water pump.

[0019] Step S205: Stop the clean water pump.

[0020] Optionally, the dosing system includes a pipeline mixer, an antiscalant metering tank and an antiscalant dosing pneumatic valve;

[0021] Before putting the dosing system into operation, open the antiscalant dosing pneumatic valve in advance, so that the descaling agent in the antiscalant metering box passes through the antiscalant dosing pneumatic valve into the pipeline mixer and mixes with the preliminary filtered water output by the activated carbon filter, and descaling the preliminary filtered water.

[0022] Optionally, when the first-stage reverse osmosis device is shut down, the antiscalant dosing pneumatic valve is closed with a delayed delay.

[0023] Optionally, a first pressure gauge is used to measure the outlet pressure of the clean water pump.

[0024] Optionally, a second pressure gauge is used to measure the inlet pressure of the first high-pressure pump.

[0025] Optionally, the first pressure gauge, the second pressure gauge, the recirculation valve, the flushing and sewage manual valve, the first high-pressure pump, the second high-pressure pump, the first fresh water pump, and the second fresh water pump are electrically connected to the PLC control system respectively.

[0026] Optionally, in step S104, under the action of the first high-pressure pump, the preliminary filtered water output by the activated carbon filter is mixed with the descaling agent output by the dosing system and then passes through the security filter and the first high-pressure pump in sequence to enter the primary reverse osmosis device.

[0027] Optionally, when the outlet pressure of the clean water pump reaches a preset value, the recirculation valve is opened in an interlocked manner to reduce the pressure of the raw water entering the fine sand filter.

[0028] Optionally, an SDI analyzer is used to sample and analyze the first flushing drainage, the second flushing drainage, and the third flushing drainage to determine whether the water quality is qualified.

[0029] A technical effect of the present invention is:

[0030] In the embodiment of the present application, a direct connection design between the activated carbon filter and the first-stage reverse osmosis device is achieved by adding a recirculation pipeline, a recirculation valve and a flushing and draining electric valve, thereby avoiding the need for an intermediate water tank and a water pump between the two, thereby optimizing the raw water pretreatment system. This not only greatly saves construction costs, but also helps to maintain the operational stability of the raw water pretreatment system, and better ensures the desalted water preparation efficiency of the high-temperature gas-cooled reactor raw water pretreatment system.

[0031] Furthermore, the method for preparing demineralized water in a high-temperature gas-cooled reactor optimizes the control logic. By controlling the opening or closing of the flushing and draining electric valve, the pressure of the first high-pressure pump is ensured to be stable, avoiding the triggering of overpressure and low-pressure protection signals, realizing the full-automatic startup and shutdown requirements of the first-stage reverse osmosis device, avoiding the instability of manually controlling the flushing and draining manual valve, reducing the labor input, and improving the water production efficiency. Description of the Drawings

[0032] Figure 1 It is a schematic flow chart of a method for preparing demineralized water in a high-temperature gas-cooled reactor according to an embodiment of the present invention;

[0033] Figure 2 It is a schematic structural diagram of a raw water pretreatment system of a method for preparing demineralized water in a high-temperature gas-cooled reactor according to an embodiment of the present invention.

[0034] In the figure: 1, clear water tank; 2, clear water pump; 3, recirculation pipeline; 4, recirculation valve; 5, flushing and draining manual valve; 6, flushing and draining electric valve; 7, sewage collection unit; 8, fine sand filter; 9, activated carbon filter; 10, dosing system; 101, pipeline mixer; 102, scale inhibitor metering tank; 103, scale inhibitor dosing pneumatic valve; 11, first high-pressure pump; 12, first-stage reverse osmosis device; 13, first-stage fresh water tank; 14, first-stage fresh water pump; 15, second high-pressure pump; 16, second-stage reverse osmosis device; 17, second-stage fresh water tank; 18, second-stage fresh water pump; 19, EDI desalination device; 20, first pressure gauge; 21, second pressure gauge. Detailed Embodiments

[0035] Now, various exemplary embodiments of the present application will be described in detail with reference to the drawings. It should be noted that: Unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present application.

[0036] The embodiments of the present application will be described in detail below. The examples of the embodiments are shown in the drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present application and should not be construed as limiting the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the scope of protection of the present application.

[0037] The terms "first" and "second" in the description and claims of this application may explicitly or implicitly include one or more of such features. In the description of this application, unless otherwise specified, the meaning of "a plurality" is two or more. In addition, "and / or" in the description and claims means at least one of the connected objects, and the character " / " generally means an "or" relationship between the associated objects before and after.

[0038] In the description of this application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0039] In the description of this application, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0040] According to the first aspect of the present invention, referring to Figure 1 and Figure 2 , a method for preparing demineralized water in a high-temperature gas-cooled reactor is provided, including:

[0041] Step S101: Operate the raw water pretreatment system, open the manual flushing and draining valve 5, and the raw water in the clear water tank 1 is circulated into the clear water tank 1 through the recirculation pipeline 3 under the action of the clear water pump 2.

[0042] Step S102: According to the outlet signal of the clear water pump 2, interlock and close the recirculation valve 4 on the recirculation pipeline 3, open the electric flushing and draining valve 6, and the raw water in the clear water tank 1 sequentially passes through the clear water pump 2, the fine sand filter 8, the activated carbon filter 9, the manual flushing and draining valve 5, and the electric flushing and draining valve 6 and enters the sewage collection unit 7 for the first flushing and draining.

[0043] Step S103: Take a sample and analyze the first flushing and draining water, and operate the dosing system 10 after the water quality is qualified.

[0044] Step S104: Start the first high-pressure pump 11 and simultaneously close the flushing and sewage discharge electric valve 6. The preliminarily filtered water output by the activated carbon filter 9 is mixed with the scale inhibitor output by the dosing system 10 and then enters the first-stage reverse osmosis device 12 through the first high-pressure pump 11 for the second flushing and drainage;

[0045] Step S105: Take a sample and analyze the second flushing and drainage. After the water quality is qualified, the first-stage demineralized water output by the first-stage reverse osmosis device 12 enters the first-stage fresh water tank 13. When the liquid level of the first-stage fresh water tank 13 reaches the first preset liquid level, start the second high-pressure pump 15 and the first-stage fresh water pump 14. The first-stage demineralized water in the first-stage fresh water tank 13 sequentially passes through the first-stage fresh water pump 14 and the second high-pressure pump 15 and enters the second-stage reverse osmosis device 16 for the third flushing and drainage;

[0046] Step S106: Take a sample and analyze the third flushing and drainage. After the water quality is qualified, the second-stage demineralized water output by the second-stage reverse osmosis device 16 enters the second-stage fresh water tank 17. When the liquid level of the second-stage fresh water tank 17 reaches the second preset liquid level, start the second-stage fresh water pump 18. The second-stage demineralized water in the second-stage fresh water tank 17 passes through the second-stage fresh water pump 18 and enters the EDI desalination device 19, and the desalinated water that meets the requirements is output by the EDI desalination device 19.

[0047] In the embodiment of the present application, by adding a recirculation pipeline 3, a recirculation valve 4, and a flushing and sewage discharge electric valve 6, a direct connection design between the activated carbon filter 9 and the first-stage reverse osmosis device 12 is realized, avoiding the setting of an intermediate water tank and a water pump between the two, thereby optimizing the raw water pretreatment system, not only greatly saving the construction cost, but also contributing to maintaining the operation stability of the raw water pretreatment system, and preferably ensuring the desalinated water preparation efficiency of the raw water pretreatment system of the high-temperature gas-cooled reactor.

[0048] Furthermore, the desalinated water preparation method of the high-temperature gas-cooled reactor optimizes the control logic. By controlling the opening or closing of the flushing and sewage discharge electric valve 6, the pressure of the first high-pressure pump 11 is ensured to be stable, avoiding the triggering of overpressure and low-pressure protection signals, realizing the full-automatic operation and shutdown requirements of the first-stage reverse osmosis device 12, avoiding the instability of manually controlling the flushing and sewage discharge manual valve 5, reducing the labor input, and improving the water production efficiency.

[0049] In a specific implementation manner, a flushing and sewage discharge electric valve 6 is added to the inlet sewage pipe of the first-stage reverse osmosis device 12. The opening or closing of the flushing and sewage discharge electric valve 6 is controlled by the PLC control system 22, and the start and stop of the first high-pressure pump 11 are interlocked, which helps to maintain the system pressure stability and avoid the triggering of a pump trip due to the low pressure of the first high-pressure pump 11.

[0050] Optionally, the desalinated water preparation method of the high-temperature gas-cooled reactor further includes:

[0051] Step S201: Shut down the raw water pretreatment system, shut down the EDI desalination device 19, close the secondary fresh water pump 18, and open the drain valve of the secondary reverse osmosis device 16.

[0052] Step S202: Shut down the secondary reverse osmosis device 16, close the second high-pressure pump 15 and the primary fresh water pump 14, and open the drain valve of the primary reverse osmosis device 12.

[0053] Step S203: Shut down the primary reverse osmosis device 12, close the first high-pressure pump 11, and open the flushing and sewage pneumatic valve.

[0054] Step S204: Shut down the fine sand filter 8 and the activated carbon filter 9, open the recirculation valve 4 on the recirculation pipeline 3, and the raw water in the clear water tank 1 is circulated into the clear water tank 1 through the recirculation pipeline 3 under the action of the clear water pump 2.

[0055] Step S205: Shut down the clear water pump 2.

[0056] In the above embodiment, the shutdown of the raw water pretreatment system can be controlled quickly and stably, and it can ensure that each device such as the secondary reverse osmosis device 16 and the primary reverse osmosis device 12 is shut down as required.

[0057] Optionally, the dosing system 10 includes a pipeline mixer 101, a scale inhibitor metering tank 102, and a scale inhibitor dosing pneumatic valve 103.

[0058] Before starting the dosing system 10, open the scale inhibitor dosing pneumatic valve 103 in advance, so that the scale inhibitor in the scale inhibitor metering tank 102 enters the pipeline mixer 101 through the scale inhibitor dosing pneumatic valve 103 and mixes with the preliminarily filtered water output by the activated carbon filter 9, and scale removal is performed on the preliminarily filtered water.

[0059] In the above embodiment, the dosing system 10 and the control logic are optimized, the siphon phenomenon is overcome, the reliability of the automatic operation of the raw water pretreatment system is improved, resource waste is prevented, and it is economical and environmentally friendly.

[0060] In addition, the dosing system 10 can effectively prevent the siphon from occurring in the raw water pretreatment system after shutdown, resulting in the liquid medicine in the scale inhibitor metering tank 102 being emptied through the drain pipe of the SDI analyzer's measurement sampling rack.

[0061] Optionally, when shutting down the primary reverse osmosis device 12, delay closing the scale inhibitor dosing pneumatic valve 103. This can better destroy the siphon at the dosing system 10 during the shutdown of the primary reverse osmosis device 12 and prevent the liquid medicine from being lost due to siphon.

[0062] Optionally, the first pressure gauge 20 is used to measure the outlet pressure of the clean water pump 2. This can monitor the outlet pressure of the clean water pump 2 in real time, which helps to adjust whether to put the recirculation pipeline 3 into operation according to the outlet pressure of the clean water pump 2, and helps to ensure the stability of the operation of the raw water pretreatment system.

[0063] Optionally, a second pressure gauge 21 is used to measure the inlet pressure of the first high-pressure pump 11. This can monitor the inlet pressure of the first high-pressure pump 11 in real time, ensure the safety and stability of the operation of the first high-pressure pump 11, and thus help ensure the stability of the operation of the raw water pretreatment system.

[0064] Optionally, the first pressure gauge 20, the second pressure gauge 21, the recirculation valve 4, the flushing and draining manual valve 5, the first high-pressure pump 11, the second high-pressure pump 15, the first fresh water pump, and the second fresh water pump are electrically connected to the PLC control system 22 respectively. The PLC control system 22 can timely open or close the first pressure gauge 20, the second pressure gauge 21, the recirculation valve 4, the flushing and draining manual valve 5, the first high-pressure pump 11, the first fresh water pump, the second fresh water pump and other components to meet the requirements of commissioning, operation, and shutdown of the raw water pretreatment system. Moreover, the PLC control system 22 can optimize the overall logic control sequence of the raw water pretreatment system to match it with the on-site equipment layout, add control signal interlocking optimization, and improve the feasibility and stability of the automatic operation of the raw water pretreatment system.

[0065] For example, the antiscalant dosing pneumatic valve 103 can be controlled by the PLC control system 22, and in the step of shutting down the first-stage reverse osmosis, a delayed closing of the antiscalant dosing pneumatic valve is added to effectively destroy the siphon and prevent the siphon loss of the liquid medicine.

[0066] Optionally, in step S104, under the action of the first high-pressure pump 11, the preliminary filtered water output by the activated carbon filter 9 is mixed with the descaling agent output by the dosing system 10 and then passes through the security filter and the first high-pressure pump 11 in sequence to enter the primary reverse osmosis device 12.

[0067] In the above embodiment, the security filter can effectively filter impurities and particulate matter in the liquid, ensure the cleanliness and purity of the medium in the pipeline and equipment such as the first high-pressure pump 11 and the first-stage reverse osmosis device 12, reduce damage and wear to the equipment, and extend the service life of the equipment.

[0068] Optionally, when the outlet pressure of the clean water pump 2 reaches a preset value, the recirculation valve 4 is opened in a chain manner to reduce the pressure of the raw water entering the fine sand filter 8. This can better protect the pressure in the fine sand filter 8 and the activated carbon filter 9, and avoid the overpressure protection action of the raw water pretreatment system causing overpressure damage to the fine sand filter 8 and the activated carbon filter 9.

[0069] Optionally, an SDI analyzer is used to sample and analyze the first flushing drainage, the second flushing drainage, and the third flushing drainage respectively to determine whether the water quality is qualified. This can simply and quickly sample and analyze each flushing drainage, ensuring the accuracy of the analysis results and also helping to improve the efficiency of the raw water pretreatment system during operation.

[0070] Therefore, the method for preparing demineralized water for a high-temperature gas-cooled reactor provided in the embodiment of the present application can effectively solve problems such as the inability to automatically start up the raw water pretreatment system of a high-temperature gas-cooled reactor and the siphon loss of liquid medicine, significantly improve the operation efficiency, avoid waste of chemical drugs, prevent the situation where the system cannot be restarted after being shut down, and ensure the stability of the raw water pretreatment system during startup and shutdown processes.

[0071] It can be understood that the above embodiments are merely exemplary embodiments adopted to illustrate the principle of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also regarded as the protection scope of the present invention.

Claims

1. A method for preparing demineralized water in a high-temperature gas-cooled reactor, characterized in that, Including: Step S101: Put the raw water pretreatment system into operation, open the manual flushing and draining valve, and the raw water in the clear water tank circulates into the clear water tank through the recirculation pipeline under the action of the clear water pump. Step S102: According to the outlet signal of the clear water pump, interlock and close the recirculation valve on the recirculation pipeline, open the electric flushing and draining valve, and the raw water in the clear water tank sequentially passes through the clear water pump, fine sand filter, activated carbon filter, manual flushing and draining valve, and electric flushing and draining valve and enters the sewage collection unit for the first flushing and drainage. Step S103: Take a sample and analyze the first flushing and drainage. After the water quality is qualified, put the dosing system into operation. Step S104: Start the first high-pressure pump and synchronously close the electric flushing and draining valve; the preliminarily filtered water output by the activated carbon filter is mixed with the scale inhibitor output by the dosing system and then enters the first-stage reverse osmosis device through the first high-pressure pump for the second flushing and drainage. Step S105: Take a sample and analyze the second flushing and drainage. After the water quality is qualified, the first-stage desalted water output by the first-stage reverse osmosis device enters the first-stage fresh water tank; when the liquid level of the first-stage fresh water tank reaches the first preset liquid level, start the second high-pressure pump and the first-stage fresh water pump, and the first-stage desalted water in the first-stage fresh water tank sequentially passes through the first-stage fresh water pump and the second high-pressure pump and enters the second-stage reverse osmosis device for the third flushing and drainage. Step S106: Take a sample and analyze the third flushing and drainage. After the water quality is qualified, the second-stage desalted water output by the second-stage reverse osmosis device enters the second-stage fresh water tank; when the liquid level of the second-stage fresh water tank reaches the second preset liquid level, start the second-stage fresh water pump, and the second-stage desalted water in the second-stage fresh water tank passes through the second-stage fresh water pump and enters the EDI desalination device, and the EDI desalination device outputs desalted water that meets the requirements.

2. The method for preparing demineralized water for a high-temperature gas-cooled reactor according to claim 1, wherein Also including: Step S201: Stop the raw water pretreatment system, stop the EDI desalination device, close the second-stage fresh water pump, and open the drainage valve of the second-stage reverse osmosis device. Step S202: Stop the second-stage reverse osmosis device, close the second high-pressure pump and the first-stage fresh water pump, and open the drainage valve of the first-stage reverse osmosis device. Step S203: Stop the first-stage reverse osmosis device, close the first high-pressure pump, and open the pneumatic flushing and draining valve. Step S204: Stop the fine sand filter and the activated carbon filter, open the recirculation valve on the recirculation pipeline, and the raw water in the clear water tank circulates into the clear water tank through the recirculation pipeline under the action of the clear water pump. Step S205: Stop the clear water pump.

3. The method for preparing demineralized water for a high-temperature gas-cooled reactor according to claim 2, characterized in that, The dosing system includes a pipeline mixer, a scale inhibitor metering tank, and a scale inhibitor dosing pneumatic valve. Before putting the dosing system into operation, open the scale inhibitor dosing pneumatic valve in advance so that the scale inhibitor in the scale inhibitor metering tank enters the pipeline mixer through the scale inhibitor dosing pneumatic valve and is mixed with the preliminarily filtered water output by the activated carbon filter, and scale removal is performed on the preliminarily filtered water.

4. The method for preparing demineralized water for a high-temperature gas-cooled reactor according to claim 3, characterized in that, When stopping the first-stage reverse osmosis device, delay closing the scale inhibitor dosing pneumatic valve.

5. The method for preparing demineralized water for a high-temperature gas-cooled reactor according to claim 4, characterized in that, Use the first pressure gauge to measure the outlet pressure of the clear water pump.

6. The method for preparing demineralized water for a high-temperature gas-cooled reactor according to claim 5, wherein Use the second pressure gauge to measure the inlet pressure of the first high-pressure pump.

7. The method for preparing demineralized water for a high-temperature gas-cooled reactor according to claim 6, wherein The first pressure gauge, the second pressure gauge, the recirculation valve, the flushing and sewage manual valve, the first high-pressure pump, the second high-pressure pump, the primary fresh water pump, and the secondary fresh water pump are electrically connected to the PLC control system respectively.

8. The method for preparing demineralized water for a high-temperature gas-cooled reactor according to claim 1, characterized in that, In step S104, under the action of the first high-pressure pump, the preliminary filtered water output by the activated carbon filter is mixed with the descaling agent output by the dosing system and then passes through the security filter and the first high-pressure pump in sequence to enter the primary reverse osmosis device.

9. The method for preparing demineralized water for a high-temperature gas-cooled reactor according to claim 5, characterized in that, When the outlet pressure of the clean water pump reaches the preset value, the recirculation valve is interlocked to open to reduce the pressure of the raw water entering the fine sand filter.

10. The method for preparing demineralized water for a high-temperature gas-cooled reactor according to claim 1, wherein The SDI analyzer is used to sample and analyze the first flushing drainage, the second flushing drainage, and the third flushing drainage to determine whether the water quality is qualified.

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