System device for secondary loop dosing

Abstract

The utility model relates to a system device for secondary loop dosing, which relates to the field of secondary loop dosing and comprises an ammonia source end, a water source end, at least two ammonia metering devices connected in parallel and at least one dosing end. The ammonia source end is connected with at least two ammonia metering devices which are connected in parallel through a pump and a switch valve; the water source end is connected with at least two ammonia metering devices which are connected in parallel through a switch valve; the at least two ammonia metering devices which are connected in parallel are connected with at least one dosing end through a switch valve. According to the system device provided by the utility model, the dosing system of the secondary loop is redesigned, and the ammonia metering equipment connected in parallel is adopted, so that the defect of unstable operation of the secondary loop caused by fluctuation of the dosing amount in the switching process is avoided, the usability of thermodynamic system equipment is improved, the service life of the thermodynamic system equipment is prolonged, and long-term and stable operation of a power plant is ensured.

Description

Technical Field

[0001] The utility model relates to the field of secondary circuit dosing, in particular to a system device for secondary circuit dosing. Background Art

[0002] Currently, ammonia / hydrazine is added to the secondary circuits of nuclear and thermal power plants to improve water quality in these systems, reducing oxygen corrosion and other forms of chemical attack. Chemical dosing systems can improve the availability and service life of thermal system equipment, thereby ensuring long-term, stable operation of the power plant. These chemicals are primarily used to adjust the pH value, dissolved oxygen level, and ammonia / hydrazine content of the secondary circuits. Chemicals are typically added to the condensate system, main feedwater and startup feedwater systems, steam generator blowdown systems, and turbine building closed cooling water systems. Ammonia / hydrazine solutions are added to the steam generator blowdown system to mitigate oxygen corrosion during wet maintenance of steam generators and to reduce dissolved oxygen content in the feedwater.

[0003] For example, CN110713220A discloses a system and method for adding hydrazine, a deoxidizer, to the secondary circuit system of a high-temperature gas-cooled reactor nuclear power plant. The system includes a water feed ammonia adding device arranged on the outlet pipe of a high-pressure heater for adding hydrazine, and a sampling and monitoring device arranged at the inlet pipe of a steam generator for monitoring the dissolved oxygen and hydrazine content for controlling the amount of hydrazine added. This solution minimizes the flow-accelerated corrosion rate of the secondary circuit water feed system without changing the chemical water treatment agent in the secondary circuit of the nuclear power unit and only changing the hydrazine dosing position. The utility model also changes the sampling position of the secondary circuit system to make the samples taken more reasonable and representative.

[0004] However, in the current chemical dosing system, during the ammonia / hydrazine dispensing process, the electric valve has a slow opening and closing time, and each valve has a different opening and closing time, resulting in different dosing concentrations during the dispensing process. At the same time, the liquid level in the solution tank is different. During the solution tank switching process, the valve opening and closing time is long, which will cause problems such as solution tank cross-contamination, resulting in inaccurate dosing and unstable operation of the secondary circuit. Utility Model Content

[0005] In view of the problems existing in the prior art, the purpose of the present invention is to provide a system device for secondary circuit dosing to solve the defect that the current dosing system cannot stably operate the secondary circuit due to inaccurate dosing caused by uncoordinated valve opening and closing.

[0006] To achieve this purpose, the present invention adopts the following technical solutions:

[0007] The utility model provides a system device for secondary circuit dosing, the system device comprising:

[0008] Ammonia source end, water source end, at least two ammonia metering devices in parallel, and at least one dosing end;

[0009] The ammonia source is connected to at least two ammonia metering devices connected in parallel via a pump and a switch valve;

[0010] The water source end is connected to at least two ammonia metering devices connected in parallel via a switch valve;

[0011] The at least two ammonia metering devices connected in parallel are connected to at least one dosing end via a switch valve.

[0012] The system device provided by the utility model redesigns the dosing system of the secondary circuit and adopts parallel ammonia metering equipment, thereby avoiding the defect of unstable operation of the secondary circuit caused by fluctuations in the dosing amount during the switching process, improving the availability and service life of the thermal system equipment, thereby ensuring the long-term, stable and operation of the power plant.

[0013] As a preferred technical solution of the present invention, the ammonia source end includes a liquid storage device and a helium source.

[0014] As a preferred technical solution of the present invention, the helium source is connected to the liquid storage device through a first isolation valve, a pressure reducing valve, a solenoid valve and a second isolation valve in sequence.

[0015] As a preferred technical solution of the present invention, the liquid storage device is also equipped with a pressure relief safety component.

[0016] As a preferred technical solution of the present invention, the pressure relief safety assembly includes a safety valve, an absorber and a ball valve connected in sequence.

[0017] As a preferred technical solution of the present utility model, the safety valve is connected to a liquid storage device.

[0018] As a preferred technical solution of the present invention, the at least two ammonia metering devices connected in parallel are connected to at least one dosing end via a pipeline provided with a switch valve.

[0019] As a preferred technical solution of the present invention, when ≥2 dosing ends are provided, the at least two ammonia metering devices connected in parallel are respectively connected to the at least two dosing ends via parallel pipelines provided with switch valves.

[0020] As a preferred technical solution of the present invention, the dosing end is connected to the dosing point via a pump.

[0021] As a preferred technical solution of the present invention, an exhaust device is provided on the pipeline between the pump and the dosing point.

[0022] Compared with the existing technical solutions, the present invention has the following beneficial effects:

[0023] (1) The device provided by the utility model can accurately control the volume of the dosing and the volume of the desalted water, thereby accurately controlling the dosing amount and solving the problem of inconsistent dosing concentration caused by inconsistent opening and closing times of the electric valve.

[0024] (2) Add exhaust to the pump outlet pipe to solve the problem of pump failure, so that normal drug addition can be carried out to the system.

[0025] (3) Ammonia / hydrazine storage tanks are equipped with nitrogen sealing measures and supporting facilities such as pressure reducing valves and safety valves required for nitrogen sealing; at the same time, respirators are installed to isolate the gas and prevent the escape of volatile gases. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of a system device for secondary circuit dosing provided by an embodiment of the utility model;

[0027] Figure 2 This is a schematic diagram of a system device for secondary circuit dosing provided in Example 1 of the present utility model;

[0028] Figure 3 This is a schematic diagram of a system device for secondary circuit dosing provided in Example 2 of the present utility model;

[0029] Figure 4 This is a schematic diagram of a system device for secondary circuit dosing provided in Example 3 of the present utility model;

[0030] Figure 5 This is a schematic diagram of a system device for secondary circuit dosing provided in Example 4 of the present utility model.

[0031] In the figure: 100-ammonia source, 110-liquid storage equipment, 111-safety valve, 112-absorber, 113-ball valve, 120-helium source, 121-first isolation valve, 122-pressure reducing valve, 123-solenoid valve, 124-second isolation valve, 200-water source, 300-ammonia metering equipment, 400-dosing end, 410-dosing point, 420-exhaust equipment, 500-pump, 600-switch valve.

[0032] The following is a further detailed description of the present invention. However, the following examples are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims. DETAILED DESCRIPTION

[0033] In order to better illustrate the present invention and facilitate understanding of the technical solution of the present invention, typical but non-limiting embodiments of the present invention are as follows:

[0034] This embodiment provides a system device for secondary circuit dosing, such as Figure 1 As shown, the system device includes:

[0035] Ammonia source end 100, water source end 200, at least two ammonia metering devices 300 connected in parallel, at least one dosing end 400;

[0036] The ammonia source end 100 is connected to at least two ammonia metering devices 300 connected in parallel via a pump 500 and a switch valve 600;

[0037] The water source end 200 is connected to at least two ammonia metering devices 300 connected in parallel via a switch valve 600;

[0038] The at least two ammonia metering devices 300 connected in parallel are connected to at least one dosing end 400 via a switch valve 600 .

[0039] In the present invention, the dosing end 400 is configured specifically according to the dosing point 410 required by the secondary circuit, and the specific number can be selected based on actual conditions. For example, the dosing objects can be selected as the condensate system, the main feed water and startup feed water system, the steam generator sewage system and the turbine plant closed cooling water system.

[0040] The ammonia source end 100 includes a liquid storage device 110 and a helium source 120 .

[0041] In the present invention, the ammonia source provided by the ammonia source end 100 includes aqueous ammonia and / or vicinal ammonia.

[0042] In the present invention, the water provided by the water source end 200 can be tap water, industrial water, industrial return water and other available water sources, such as desalted water.

[0043] The helium source 120 is connected to the liquid storage device 110 through a first isolation valve 121 , a pressure reducing valve 122 , a solenoid valve 123 and a second isolation valve 124 in sequence.

[0044] In the present invention, a helium source 120 is provided for sealing the liquid storage device 110 .

[0045] The liquid storage device 110 is also equipped with a pressure relief safety component.

[0046] The pressure relief safety assembly includes a safety valve 111 , an absorber 112 and a ball valve 113 which are connected in sequence.

[0047] The safety valve 111 is connected to the liquid storage device 110 .

[0048] In the present invention, the pressure relief safety component is used to relieve the excessive pressure of the liquid storage device 110 , and the absorber 112 is used to isolate the gas to prevent the escape of volatile gas.

[0049] The at least two ammonia metering devices 300 connected in parallel are connected to at least one dosing end 400 via a pipeline provided with a switch valve 600 .

[0050] When the number of the dosing terminals 400 is ≥ 2, the at least two ammonia metering devices 300 connected in parallel are respectively connected to the at least two dosing terminals 400 via parallel pipelines provided with switch valves 600 .

[0051] The dosing end 400 is connected to the dosing point 410 via a pump 500 .

[0052] An exhaust device 420 is provided on the pipeline between the pump 500 and the dosing point 410 .

[0053] Exemplarily, during the dosing process, at least two ammonia metering devices 300 connected in parallel are used alternately, so that the medicine is prepared before being fed into the corresponding dosing end 400 to avoid fluctuations in the dosing amount. Specifically, when the ammonia liquid used in one ammonia metering device 300 reaches the liquid level at which drainage stops, the corresponding switch valve 600 is closed to stop drainage. At this time, the switch valve 600 of another ammonia metering device 300 (ammonia liquid has been prepared in advance) is opened to transport the ammonia liquid of the other ammonia metering device 300 to the dosing end 400, and the ammonia metering device 300 with a low liquid level starts to prepare liquid. Exemplarily, the ammonia source end 100 is opened to feed ammonia liquid to a predetermined liquid level, and then the feeding of ammonia liquid is stopped. Then, the water source end 200 is opened to feed water to a predetermined liquid level. When the amount of liquid fed is greater than the predetermined amount, the dosing amount can be controlled to decrease or increase.

[0054] Furthermore, in order to illustrate the dosing effect that can be achieved by the system device for secondary circuit dosing provided by the present invention, the following examples are used for illustration, as follows:

[0055] Example 1

[0056] The embodiment provides a system device for secondary circuit dosing, such as Figure 2 As shown, the system device includes:

[0057] Ammonia source end 100, water source end 200, two parallel ammonia metering devices 300 and two dosing ends 400;

[0058] The ammonia source end 100 is connected to two ammonia metering devices 300 connected in parallel via a pump 500 and a switch valve 600;

[0059] The water source end 200 is connected to two ammonia metering devices 300 connected in parallel via a switch valve 600;

[0060] The two parallel ammonia metering devices 300 are connected to the two dosing terminals 400 via a switch valve 600 .

[0061] The ammonia source end 100 includes a liquid storage device 110 and a helium source 120 .

[0062] The helium source 120 is connected to the liquid storage device 110 in sequence through a first isolation valve 121 , a pressure reducing valve 122 , a solenoid valve 123 and a second isolation valve 124 ; the helium source 120 is provided to seal the liquid storage device 110 .

[0063] The liquid storage device 110 is also equipped with a pressure relief safety component.

[0064] The pressure relief safety assembly includes a safety valve 111 , an absorber 112 and a ball valve 113 which are connected in sequence.

[0065] The safety valve 111 is connected to the liquid storage device 110 .

[0066] Since ≥2 dosing terminals 400 are provided, the two parallel ammonia metering devices 300 are connected to the two dosing terminals 400 respectively via parallel pipelines provided with switch valves 600 .

[0067] The dosing end 400 is connected to the dosing point 410 via a pump 500 .

[0068] An exhaust device 420 is provided on the pipeline between the pump 500 and the dosing point 410 .

[0069] Example 2

[0070] The embodiment provides a system device for secondary circuit dosing, such as Figure 3 As shown, the system device includes:

[0071] Ammonia source end 100, water source end 200, two parallel ammonia metering devices 300 and three dosing ends 400;

[0072] The ammonia source end 100 is connected to two ammonia metering devices 300 connected in parallel via a pump 500 and a switch valve 600;

[0073] The water source end 200 is connected to two ammonia metering devices 300 connected in parallel via a switch valve 600;

[0074] The two parallel ammonia metering devices 300 are connected to the three dosing terminals 400 via a switch valve 600 .

[0075] The ammonia source end 100 includes a liquid storage device 110 and a helium source 120 .

[0076] The helium source 120 is connected to the liquid storage device 110 in sequence through a first isolation valve 121 , a pressure reducing valve 122 , a solenoid valve 123 and a second isolation valve 124 ; the helium source 120 is provided to seal the liquid storage device 110 .

[0077] The liquid storage device 110 is also equipped with a pressure relief safety component.

[0078] The pressure relief safety assembly includes a safety valve 111 , an absorber 112 and a ball valve 113 which are connected in sequence.

[0079] The safety valve 111 is connected to the liquid storage device 110 .

[0080] Since ≥2 dosing terminals 400 are provided, the two parallel ammonia metering devices 300 are connected to the three dosing terminals 400 respectively via parallel pipelines provided with switch valves 600 .

[0081] The dosing end 400 is connected to the dosing point 410 via a pump 500 .

[0082] An exhaust device 420 is provided on the pipeline between the pump 500 and the dosing point 410 .

[0083] Example 3

[0084] The embodiment provides a system device for secondary circuit dosing, such as Figure 4 As shown, the system device includes:

[0085] Ammonia source end 100, water source end 200, three parallel ammonia metering devices 300 and four dosing ends 400;

[0086] The ammonia source 100 is connected to three ammonia metering devices 300 connected in parallel via a pump 500 and a switch valve 600;

[0087] The water source end 200 is connected to three ammonia metering devices 300 connected in parallel via a switch valve 600;

[0088] The three parallel ammonia metering devices 300 are connected to the four dosing terminals 400 via a switch valve 600 .

[0089] The ammonia source end 100 includes a liquid storage device 110 and a helium source 120 .

[0090] The helium source 120 is connected to the liquid storage device 110 in sequence through a first isolation valve 121 , a pressure reducing valve 122 , a solenoid valve 123 and a second isolation valve 124 ; the helium source 120 is provided to seal the liquid storage device 110 .

[0091] The liquid storage device 110 is also equipped with a pressure relief safety component.

[0092] The pressure relief safety assembly includes a safety valve 111 , an absorber 112 and a ball valve 113 which are connected in sequence.

[0093] The safety valve 111 is connected to the liquid storage device 110 .

[0094] Since ≥2 dosing terminals 400 are provided, the three parallel ammonia metering devices 300 are connected to the four dosing terminals 400 respectively via parallel pipelines provided with switch valves 600 .

[0095] The dosing end 400 is connected to the dosing point 410 via a pump 500 .

[0096] An exhaust device 420 is provided on the pipeline between the pump 500 and the dosing point 410 .

[0097] Example 4

[0098] The embodiment provides a system device for secondary circuit dosing, such as Figure 5 As shown, the system device includes:

[0099] Ammonia source end 100, water source end 200, two parallel ammonia metering devices 300 and four dosing ends 400;

[0100] The ammonia source end 100 is connected to two ammonia metering devices 300 connected in parallel via a pump 500 and a switch valve 600;

[0101] The water source end 200 is connected to two ammonia metering devices 300 connected in parallel via a switch valve 600;

[0102] The two parallel ammonia metering devices 300 are connected to the four dosing terminals 400 via a switch valve 600 .

[0103] The ammonia source end 100 includes a liquid storage device 110 and a helium source 120 .

[0104] The helium source 120 is connected to the liquid storage device 110 in sequence through a first isolation valve 121 , a pressure reducing valve 122 , a solenoid valve 123 and a second isolation valve 124 ; the helium source 120 is provided to seal the liquid storage device 110 .

[0105] The liquid storage device 110 is also equipped with a pressure relief safety component.

[0106] The pressure relief safety assembly includes a safety valve 111 , an absorber 112 and a ball valve 113 which are connected in sequence.

[0107] The safety valve 111 is connected to the liquid storage device 110 .

[0108] Since ≥2 dosing terminals 400 are provided, the two parallel ammonia metering devices 300 are connected to the four dosing terminals 400 respectively via parallel pipelines provided with switch valves 600 .

[0109] The dosing end 400 is connected to the dosing point 410 via a pump 500 .

[0110] An exhaust device 420 is provided on the pipeline between the pump 500 and the dosing point 410 .

[0111] The above embodiment is used to provide a system device for secondary circuit dosing to add ammonia to the secondary circuit system. During the dosing process, the dosing volume and the desalted water volume can be accurately controlled, thereby accurately controlling the dosing amount and solving the problem of inconsistent dosing concentration caused by inconsistent opening and closing times of the electric valve. At the same time, exhaust equipment is provided on the pipeline before the dosing point to avoid the problem of pump failure, so that normal dosing can be carried out to the system.

[0112] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details of the above embodiments. Within the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the scope of protection of the present invention.

[0113] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0114] In addition, the various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A system device for secondary circuit dosing, characterized in that: The system device includes: Ammonia source, water source, at least two ammonia metering devices in parallel, and at least one dosing terminal; The ammonia source is connected to at least two ammonia metering devices connected in parallel via a pump and a switch valve; The water source end is connected to at least two ammonia metering devices connected in parallel via a switch valve; The at least two ammonia metering devices connected in parallel are connected to at least one dosing end via a switch valve.

2. The system device according to claim 1, wherein: The ammonia source end includes a liquid storage device and a helium source.

3. The system device according to claim 2, characterized in that: The helium source is connected to the liquid storage device through a first isolation valve, a pressure reducing valve, a solenoid valve and a second isolation valve in sequence.

4. The system device according to claim 2, wherein: The liquid storage device is also equipped with a pressure relief safety component.

5. The system device according to claim 4, characterized in that: The pressure relief safety assembly includes a safety valve, an absorber and a ball valve which are connected in sequence.

6. The system device according to claim 5, characterized in that: The safety valve is connected to the liquid storage device.

7. The system device according to claim 1, wherein: The at least two ammonia metering devices connected in parallel are connected to at least one dosing end via a pipeline provided with a switch valve.

8. The system device according to claim 7, characterized in that: When the number of the dosing ends is ≥2, the at least two ammonia metering devices connected in parallel are respectively connected to the at least two dosing ends via parallel pipelines provided with switch valves.

9. The system device according to claim 1, wherein: The dosing end is connected to the dosing point through a pump.

10. The system device according to claim 9, characterized in that: An exhaust device is provided on the pipeline between the pump and the dosing point.

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