Liquid metal reactor loop cleaning test device

Abstract

The utility model discloses a liquid metal pile loop cleaning test device which comprises a chemical cleaning loop which comprises a water storage tank, a circulating pump, a high-pressure pump, an electromagnetic flowmeter and a pipe sample to be cleaned, and the water storage tank, the circulating pump, the high-pressure pump, the electromagnetic flowmeter and the pipe sample to be cleaned are sequentially connected end to end; the water quality control unit comprises a dosing tank, a resin bed and a deoxidizing tank, the deoxidizing tank is connected with the water tank, and the dosing tank, the resin bed, the water storage tank and the circulating pump form a circulating branch; the heating unit comprises a temperature adjusting assembly and a heater, the temperature adjusting assembly is at least arranged in front of a water inlet of the to-be-cleaned pipe sample to adjust the water temperature, and the heater heats the to-be-cleaned pipe sample to simulate the actual temperature working condition. The high-pressure pump guarantees the pressure in a chemical cleaning loop, the water quality control unit controls the water quality, the heating unit controls the water quality and the temperature of a to-be-cleaned pipeline, the actual working condition and the water quality of a to-be-cleaned pipe sample are reduced as much as possible, and the actual cleaning effect and the safety of a loop pipe base body are verified.

Description

Technical Field

[0001] This utility model relates to the field of chemical cleaning technology for fouling in nuclear power liquid metal reactor units, and in particular to a liquid metal reactor loop cleaning test device. Background Technology

[0002] During long-term operation of nuclear power plants, corrosion products frequently accumulate on the heat transfer tubes of steam generators, affecting their heat exchange efficiency and potentially causing scaling corrosion. For units using once-through steam generators, there are also issues with throttling components clogging or scaling. Therefore, it is necessary to clean the secondary side of the steam generator to reduce surface fouling. Chemical cleaning offers several significant advantages over traditional secondary loop water flushing in nuclear power plants: it provides a more thorough cleaning, completely removing corrosion products from the system; and it provides better re-corrosion protection after chemical cleaning, effectively preventing secondary corrosion.

[0003] Compared to traditional pressurized water reactors, liquid metal reactors have higher temperature and pressure in their secondary loop, and use a direct-flow steam generator with spiral heat transfer tubes and no blowdown device.

[0004] Currently, a dynamic simulation test device for chemical cleaning of the secondary loop of a high-temperature gas-cooled reactor nuclear power unit is available on the market. This simulation device mainly consists of a cleaning water tank, a circulating pump, an electromagnetic flowmeter, a tube sample clamping device, an electrochemical online corrosion measurement device, and an electric heating device. It can simulate the series and parallel cleaning of heat exchange tubes of different diameters and monitor corrosion online during the cleaning process. However, this test device only uses the electric heating device to heat the cleaning solution before conducting the cleaning test, and cannot simulate the actual cleaning conditions of the tube samples to be cleaned. The cleaning effect obtained may differ significantly from the effect applied in actual power plants. Moreover, this simulation test device does not control the water quality during the cleaning test, so the corrosion rate of the tube samples measured by chemical cleaning may also deviate significantly from the actual application conditions, resulting in limited reference value for engineering applications. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide a liquid metal stack loop cleaning test device.

[0006] The technical solution adopted by this utility model to solve its technical problem is: a liquid metal stack loop cleaning test device, comprising:

[0007] A chemical cleaning circuit includes a water tank, a circulating pump, a high-pressure pump, an electromagnetic flow meter, and a tube sample to be cleaned, wherein the water tank, the circulating pump, the high-pressure pump, the electromagnetic flow meter, and the tube sample to be cleaned are connected sequentially.

[0008] The water quality control unit includes a dosing tank, a resin bed, and a deaerator. The deaerator is connected to the water tank, and the dosing tank, the resin bed, the water storage tank, and the circulation pump form a circulation branch.

[0009] The heating unit includes a temperature regulating component and a heater. The temperature regulating component is located at least before the water inlet of the tube sample to be cleaned to regulate the water temperature, and the heater heats the tube sample to be cleaned to simulate actual temperature conditions.

[0010] In some embodiments, the temperature control assembly includes a heat exchanger, a condenser, and a preheater. The cold end inlet of the heat exchanger is connected to the outlet of the electromagnetic flowmeter, the cold end outlet of the heat exchanger is connected to the inlet of the tube sample to be cleaned through the preheater, the hot end inlet of the heat exchanger is connected to the outlet of the tube sample to be cleaned, and the hot end outlet of the heat exchanger is connected to the water tank through the condenser.

[0011] In some embodiments, the heater includes at least one of a heating furnace, a heating coil, and a heating wire, with the tube sample to be cleaned placed in the heating furnace; and / or the heating coil is fitted over the outside of the tube sample to be cleaned; and / or the heating wire is connected to both ends of the tube sample to be cleaned.

[0012] In some embodiments, the water quality control unit further includes a dissolved oxygen probe, which is located in the circulation branch and connected in parallel with the dosing tank and the resin bed, respectively.

[0013] In some embodiments, the water quality control unit further includes a dissolved hydrogen probe, which is disposed in the circulation branch and connected in parallel with the dosing tank and the resin bed, respectively.

[0014] In some embodiments, the water quality control unit further includes an online pH meter, which is located in the circulation branch and connected in parallel with the dosing tank and the resin bed, respectively.

[0015] In some embodiments, the water quality control unit further includes a conductivity meter, which is located in the circulation branch and connected in parallel with the dosing tank and the resin bed, respectively.

[0016] In some embodiments, the water quality control unit further includes a water inlet, which is located in the circulation branch and at the rear end of the dosing tank and the resin bed.

[0017] In some embodiments, the water quality control unit further includes a water outlet, which is located in the chemical cleaning circuit and at the rear end of the temperature control component, close to the water storage tank.

[0018] In some embodiments, the deoxygenation tank contains nitrogen or hydrogen.

[0019] By implementing this utility model, the following beneficial effects can be achieved:

[0020] This utility model discloses a liquid metal stack loop cleaning test device, comprising: a chemical cleaning loop, including a water storage tank, a circulating pump, a high-pressure pump, an electromagnetic flowmeter, and a tube sample to be cleaned, wherein the water storage tank, the circulating pump, the high-pressure pump, the electromagnetic flowmeter, and the tube sample to be cleaned are connected sequentially; a water quality control unit, including a dosing tank, a resin bed, and a deaerator, wherein the deaerator is connected to the water tank, and the dosing tank, the resin bed, the water storage tank, and the circulating pump form a circulation branch; and a heating unit, including a temperature regulating component and a heater, wherein the temperature regulating component is located at least before the inlet of the tube sample to be cleaned to regulate the water temperature, and the heater heats the tube sample to be cleaned to simulate actual temperature conditions. The chemical cleaning loop uses a high-pressure pump to ensure that the pressure in the chemical cleaning loop meets the requirements of the cleaning test. The water quality control unit controls the water quality in the chemical cleaning loop, and the heating unit controls both the water quality and the temperature of the heating unit to simulate the on-site temperature environment. The liquid metal stack loop cleaning test device of this invention can restore the actual working conditions and water quality of the pipe sample to be cleaned as much as possible, so as to verify the actual cleaning effect of chemical cleaning and the safety of the loop pipe substrate. Attached Figure Description

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0022] Figure 1 This is a schematic diagram of the structure of a liquid metal stack loop cleaning test device according to an embodiment of the present invention. Detailed Implementation

[0023] To provide a clearer understanding of the technical features, objectives, and effects of this utility model, the specific embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0024] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0025] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model 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 utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0026] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or a chemical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0027] See Figure 1 One embodiment of this utility model discloses a liquid metal reactor loop cleaning test device, including a chemical cleaning loop, a water quality control unit, and a heating unit. The chemical cleaning loop is used to simulate cleaning the secondary loop of a liquid metal reactor in a nuclear power plant, i.e., the secondary side of the steam generator. The water quality control unit is used to control and regulate the water quality in the chemical cleaning loop and monitor the real-time water quality. The heating unit is used to adjust the water temperature in the chemical cleaning loop and the temperature of the loop to be cleaned, simulating a high-temperature environment.

[0028] The chemical cleaning loop includes a water tank 1, a circulating pump 2, a high-pressure pump 9, an electromagnetic flowmeter 13, and a pipe sample 15 to be cleaned. These components are connected sequentially. Water in the water tank 1 circulates within the chemical cleaning loop via the circulating pump 2. The high-pressure pump 9 ensures the pressure in the chemical cleaning loop meets the requirements of the cleaning test. The electromagnetic flowmeter 13 monitors the cleaning flow rate in the chemical cleaning loop. The pipe sample 15 is connected to the cleaning loop via a flange, and water flows through the middle of the sample. The pipe sample 15 simulates the structure of a steam generator heat transfer tube, or, depending on actual needs, simulates the structure of other pipe components requiring cleaning in a nuclear power plant.

[0029] The water quality control unit includes a dosing tank 3, a resin bed 8, and a deoxygenation tank 16. The deoxygenation tank 16 is connected to the water storage tank 1. The dosing tank 3, resin bed 8, water storage tank 1, and circulation pump 2 form a circulation branch. The water storage tank 1 and circulation pump 2 are shared structures for the circulation branch and the chemical cleaning circuit. Water in the water storage tank 1 circulates in the circulation branch through the circulation pump 2. The dosing tank 3 mainly adds the chemical cleaning agents to the water storage tank 1 through the circulation branch. The resin bed 8 is used to treat the water in the water storage tank 1 before the test begins, strictly limiting the ion content of the water in the chemical cleaning circuit to the actual water quality conditions. The deoxygenation tank 16 contains nitrogen gas. Before the test begins, the deoxygenation tank 16 purges nitrogen gas into the chemical cleaning circuit to remove oxygen, reducing the dissolved oxygen content in the circuit to below the limit. Understandably, in some other embodiments, the deoxygenator 16 contains hydrogen gas, which is introduced into the chemical cleaning circuit before the test begins to remove oxygen, thereby reducing the dissolved oxygen content in the circuit to below the limit.

[0030] In some embodiments, the water quality control unit may further include a dissolved oxygen probe 4, a dissolved hydrogen probe 5, an online pH meter 6, and a conductivity meter 7, which are respectively installed in the circulation branch and connected in parallel with the dosing tank 3 and the resin bed 8. The dissolved oxygen probe 4, dissolved hydrogen probe 5, online pH meter 6, and conductivity meter 7 may be all or partially connected in series. The dissolved oxygen probe 4, dissolved hydrogen probe 5, online pH meter 6, and conductivity meter 7 are used to monitor relevant water quality parameters in the chemical cleaning loop online, including dissolved oxygen (DO) concentration, dissolved hydrogen (DH) concentration, pH value, and conductivity (reflecting ion concentration). The dissolved oxygen probe 4, dissolved hydrogen probe 5, online pH meter 6, and conductivity meter 7 can be added, removed, or replaced according to actual conditions.

[0031] In some embodiments, the water quality control unit may further include an inlet water intake 17 and an outlet water intake 18. The inlet water intake 17 is located in the circulation branch and at the rear end of the dosing tank 3 and the resin bed 8. The inlet water intake 17 is used to take samples during the test. The sample taken is water before the chemical cleaning circuit is cleaned and after being treated by the dosing tank 3, the resin bed 8, and the deaerator 16. The outlet water intake 18 is located in the chemical cleaning circuit and at the rear end of the temperature control component of the heating unit, close to the water storage tank 1. The outlet water intake 18 is used to take samples during the test. The sample taken is water before it flows back to the water storage tank 1 after the chemical cleaning circuit is cleaned. The sample is used to detect water quality parameters that cannot be monitored online, such as dissolved iron content in the circuit.

[0032] Before the chemical cleaning test begins, the water in the water storage tank 1, the chemical cleaning loop and the circulation branch are treated through the resin bed 8 and the deaerator 16 so that the water quality in the loop can be restored to the chemical cleaning water quality conditions of the secondary loop of the liquid metal reactor nuclear power unit before the chemical cleaning test is carried out.

[0033] The heating unit includes a temperature control component and a heater 14. The temperature control component is located at least before the water inlet of the tube sample 15 to be cleaned to regulate the water temperature. The heater 14 heats the tube sample 15 to simulate the actual temperature conditions. The temperature control component is used to regulate the water temperature of the chemical cleaning circuit, and the heater 14 is used to directly or indirectly heat the tube sample 15 to simulate the actual temperature conditions outside the tube sample 15.

[0034] In some embodiments, the temperature control assembly includes a heat exchanger 11, a condenser 10, and a preheater 12. The cold end inlet of the heat exchanger 11 is connected to the outlet of the electromagnetic flowmeter 13, the cold end outlet of the heat exchanger 11 is connected to the inlet of the tube sample 15 to be cleaned through the preheater 12, the hot end inlet of the heat exchanger 11 is connected to the outlet of the tube sample 15 to be cleaned, and the hot end outlet of the heat exchanger 11 is connected to the water storage tank 1 through the condenser 10.

[0035] In some embodiments, the heater 14 includes at least one of three components: a heating furnace, a heating coil, and a heating wire. The tube sample 15 to be cleaned is placed in the heating furnace and heated by electricity; and / or the heating coil is fitted over the outside of the tube sample 15 to be cleaned and heated by electricity; and / or the heating wire is connected to both ends of the tube sample 15 to be cleaned and directly heated by electricity. Only one of the heating furnace, heating coil, and heating wire may be provided, or two or three may be provided as redundant alternatives.

[0036] Preferably, in this embodiment, the heater 14 is a heating furnace. By controlling the internal heating temperature of the tubular furnace to simulate the external temperature conditions during the actual cleaning of the tube sample 15, the simulated chemical cleaning effect can better reflect the real working conditions in the project.

[0037] The room-temperature water in the storage tank 1 is first sent to the heat exchanger 11 by the high-pressure pump 9, where it exchanges heat with the high-temperature water flowing out after cleaning. Then it flows to the preheater 12, where it is heated to a specified temperature before flowing into the tube sample 15 to be cleaned for chemical cleaning. After cleaning, the high-temperature water in the loop flows back to the heat exchanger 11 for initial cooling, then flows to the condenser 10 to be cooled to room temperature before flowing back to the storage tank 1. In addition, the tube sample 15 to be cleaned is placed in a tube furnace, where the internal heating is maintained at a specified temperature, up to 200°C, to simulate the actual temperature conditions on the outside of the tube sample 15.

[0038] Understandably, the water storage tank 1, circulation pump 2, high-pressure pump 9, electromagnetic flowmeter 13 and the tube sample to be cleaned 15 in the chemical cleaning circuit of this utility model, the dosing tank 3, resin bed 8 and deaerator 16, dissolved oxygen probe 4, dissolved hydrogen probe 5, online pH meter 6, conductivity meter 7, etc. in the water quality control unit, and the heat exchanger 11, condenser 10 and preheater 12, heater 14, etc. in the heating unit are all connected to each other by corrosion-resistant and high-temperature resistant pipes, such as stainless steel pipes.

[0039] By implementing this utility model, the following beneficial effects can be achieved:

[0040] This invention relates to a liquid metal stack loop cleaning test device. The chemical cleaning loop is equipped with a high-pressure pump 9 to ensure the pressure meets the requirements of the cleaning test. A water quality control unit controls the water quality in the chemical cleaning loop, and a heating unit controls both the water quality and the heating unit temperature to simulate the actual on-site temperature environment. This invention can reproduce the actual working conditions and water quality of the pipe sample to be cleaned as closely as possible, to verify the actual cleaning effect of chemical cleaning and the safety of the loop pipe substrate.

[0041] It is understood that the above embodiments only illustrate preferred embodiments of the present utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present utility model patent. It should be noted that for those skilled in the art, without departing from the concept of the present utility model, the above embodiments or technical features can be freely combined, and several modifications and improvements can be made. These all fall within the protection scope of the present utility model, that is, the embodiments described "in some embodiments" can be freely combined with any of the embodiments above and below. Therefore, all equivalent transformations and modifications made within the scope of the claims of the present utility model should fall within the coverage of the claims of the present utility model.

Claims

1. A liquid metal stack loop cleaning test device, characterized in that, include: The chemical cleaning circuit includes a water tank (1), a circulation pump (2), a high-pressure pump (9), an electromagnetic flowmeter (13), and a tube sample (15) to be cleaned, wherein the water tank (1), the circulation pump (2), the high-pressure pump (9), the electromagnetic flowmeter (13), and the tube sample (15) to be cleaned are connected sequentially. The water quality control unit includes a dosing tank (3), a resin bed (8), and a deaerator (16). The deaerator (16) is connected to the water storage tank (1). The dosing tank (3), the resin bed (8), the water storage tank (1), and the circulation pump (2) form a circulation branch. The heating unit includes a temperature control component and a heater (14). The temperature control component is located at least in front of the water inlet of the tube sample (15) to be cleaned to adjust the water temperature. The heater (14) heats the tube sample (15) to be cleaned to simulate the actual temperature conditions.

2. The liquid metal stack loop cleaning test apparatus according to claim 1, characterized in that, The temperature control assembly includes a heat exchanger (11), a condenser (10), and a preheater (12). The cold end inlet of the heat exchanger (11) is connected to the outlet of the electromagnetic flowmeter (13). The cold end outlet of the heat exchanger (11) is connected to the inlet of the tube sample (15) to be cleaned through the preheater (12). The hot end inlet of the heat exchanger (11) is connected to the outlet of the tube sample (15) to be cleaned. The hot end outlet of the heat exchanger (11) is connected to the water storage tank (1) through the condenser (10).

3. The liquid metal stack loop cleaning test apparatus according to claim 1, characterized in that, The heater (14) includes at least one of the following: a heating furnace, a heating coil, and a heating wire. The tube sample (15) to be cleaned is placed in the heating furnace; and / or the heating coil is fitted around the outside of the tube sample (15) to be cleaned; and / or the heating wire is connected to both ends of the tube sample (15) to be cleaned.

4. The liquid metal stack loop cleaning test apparatus according to any one of claims 1-3, characterized in that, The water quality control unit also includes a dissolved oxygen probe (4), which is located in the circulation branch and is connected in parallel with the dosing tank (3) and the resin bed (8).

5. The liquid metal stack loop cleaning test apparatus according to any one of claims 1-3, characterized in that, The water quality control unit also includes a dissolved hydrogen probe (5), which is located in the circulation branch and is connected in parallel with the dosing tank (3) and the resin bed (8).

6. The liquid metal stack loop cleaning test apparatus according to any one of claims 1-3, characterized in that, The water quality control unit also includes an online pH meter (6), which is located in the circulation branch and is connected in parallel with the dosing tank (3) and the resin bed (8).

7. The liquid metal stack loop cleaning test apparatus according to any one of claims 1-3, characterized in that, The water quality control unit also includes a conductivity meter (7), which is located in the circulation branch and is connected in parallel with the dosing tank (3) and the resin bed (8).

8. The liquid metal stack loop cleaning test apparatus according to any one of claims 1-3, characterized in that, The water quality control unit also includes a water inlet (17), which is located in the circulation branch and at the rear end of the dosing tank (3) and the resin bed (8).

9. The liquid metal stack loop cleaning test apparatus according to any one of claims 1-3, characterized in that, The water quality control unit also includes a water outlet (18), which is located in the chemical cleaning circuit and at the rear end of the temperature control component, close to the water storage tank (1).

10. The liquid metal stack loop cleaning test apparatus according to any one of claims 1-3, characterized in that, The deoxygenator (16) is equipped with nitrogen or hydrogen.

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