Nuclear reactor coolant non-energetic ammonia addition device and ammonia addition method thereof

Abstract

This invention discloses a passive ammonia charging device and method for nuclear reactor coolant. The passive ammonia charging device includes: a base, a charging seat, a piston, a charging switch, and a reset assembly. The base has a fusion chamber connected to the coolant system pipeline and incorporating the coolant fused with ammonia. The charging seat is mounted on the base. The piston slides through the interior of the charging seat, forming a charging chamber connected to the fusion chamber. The charging seat has a first opening. This design allows for a more uniform ammonia content, avoiding ammonia waste. The passive ammonia charging device utilizes the physical principle of continuously decreasing two-phase diffusion rates, controlling the radiation oxygen content in the coolant system pipeline through a self-decelerating ammonia charging strategy. This reduces the generation of gaseous products such as hydrogen and nitrogen, providing some protection for the equipment. Furthermore, the total amount of ammonia consumed during operation is reduced, and the passive design increases the reliability of the device.

Description

Technical Field

[0001] This invention relates to the field of nuclear power plant water treatment technology, and in particular to a passive ammonia addition device and method for nuclear reactor coolant. Background Technology

[0002] Nuclear power plants, compared to conventional thermal power plants, suffer from core radiation issues. Coolant radiolysis continuously produces corrosive substances such as oxygen and hydrogen peroxide, causing changes in water quality and threatening the safety of vulnerable structures in the coolant circuit. Adding substances such as hydrogen (H2), ammonia (NH3), or hydrazine (N2H4) to the coolant is a chemical deoxygenation method used in reactors. Among these, ammonia is often used in chemical regulation as a pH control agent and reducing agent due to its safety, economy, and ability to regulate pH to mitigate corrosion.

[0003] Traditional ammonia addition strategies are mainly divided into two categories: one-time ammonia addition and continuous ammonia addition. Some special nuclear reactors adopt a one-time ammonia addition strategy before startup, relying on sufficient ammonia to maintain the deoxygenation effect throughout the entire operation.

[0004] However, this method loses its pH control function as ammonia is depleted in the later stages. Another continuous ammonia addition strategy relies on a chemical and volume control system to continuously inject diluted ammonia water for regulation, and uses monitoring and control devices for automation. However, this method leads to a continuous increase in the concentration of ammonia-containing reaction gaseous products such as hydrogen and nitrogen, and the introduction of detection and control devices under long-term radiation oxygen production conditions also increases the overall complexity and operation and maintenance costs. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a passive ammonia addition device for nuclear reactor coolant and ammonia addition method thereof.

[0006] The technical solution adopted by this invention to solve its technical problem is as follows: A passive ammonia charging device for a nuclear reactor coolant is constructed, comprising: a base, a charging seat, a piston, a charging switch, and a reset assembly; the base has a fusion chamber connected to a coolant system pipeline and incorporating ammonia gas; the charging seat is disposed on the base; the piston is slidably connected to the interior of the charging seat, and together with the charging seat, forms a charging chamber connected to the fusion chamber; the charging seat has a first opening; the charging switch is disposed between the first opening and the charging chamber, and has a second opening; the reset assembly is installed between the piston and the charging seat; the ammonia charging device includes a charging state and a shut-off state that are switched according to the pressure in the charging chamber; in the charging state, the first opening and the second opening are connected to allow ammonia gas from the charging pipe to enter the charging chamber; in the shut-off state, the first opening and the second opening are offset to isolate the charging pipe from the charging chamber.

[0007] Furthermore, the inflation base is provided with a first slide groove, and the inflation switch includes: a slider and a slide plate; the slider is fixedly installed on one side of the piston; the slide plate is slidably connected in the first slide groove, and a damping element is provided between the slide plate and the first slide groove; a second slide groove is provided on the slide plate, and the slider is slidably connected in the second slide groove; a second opening is provided on the slide plate; when the piston moves, the slider drives the slide plate to move, so that the second opening is connected to or offset from the first opening.

[0008] Furthermore, the damping element is a sealing ring, felt, or interference fit.

[0009] Furthermore, the inflatable base includes a hollow inflatable sleeve and an end cap, one end of the inflatable sleeve being sealed to the base, and the end cap being detachably installed at the other end of the inflatable sleeve.

[0010] Furthermore, the reset assembly includes an elastic element installed between the end cap and the piston.

[0011] Furthermore, the end cap is installed on the inflatable sleeve via a threaded joint, and the reset assembly also includes a first limiting member and a second limiting member that are rotatably connected to the end cap and the piston, respectively, with both ends of the elastic member installed on the first limiting member and the second limiting member, respectively.

[0012] Furthermore, the base includes: at least one connecting pipe and a diffusion chamber, the two ends of the connecting pipe being connected to the coolant system pipeline to receive the coolant and to output the coolant after it has fused with the ammonia; the diffusion chamber is disposed between the inlet and outlet of the connecting pipe to fuse the received ammonia with the coolant.

[0013] Furthermore, the diameter of the fusion cavity is larger than the diameter of the connecting pipe; the cross-sectional area of ​​the fusion cavity on the side closer to the inflatable seat is smaller than the cross-sectional area on the side farther from the inflatable seat.

[0014] The present invention also provides a passive ammonia addition method for nuclear reactor coolant, comprising the following steps:

[0015] S1. Connect the aforementioned passive ammonia addition device for the nuclear reactor coolant to the coolant system piping;

[0016] S2. Connect one end of the inflation tube to the first opening, and connect the other end of the inflation tube to the outside ammonia gas;

[0017] S3. Ammonia gas is automatically filled into the inflation chamber through the inflation tube. The pressure difference causes the piston to move the slide plate away from the base through the slider, thus reaching the cut-off state.

[0018] S4. As the ammonia in the inflation chamber merges with the coolant in the fusion chamber, the pressure difference causes the piston to move the slide plate to one end near the base via the slider, thus achieving the inflation state.

[0019] S5. Repeat steps S3 and S4 above until all the ammonia in the outside is consumed, then add ammonia again; or continuously fill the enclosed space with ammonia.

[0020] Furthermore, the cutoff state in step S3 specifically means that the ammonia gas filled into the inflation chamber will move the piston away from the base, causing the piston to drive the slider to slide away from the base in the second groove; until the slider moves to the end of the slide plate away from the base, the piston, which continues to move, will cause the second opening on the slide plate to be misaligned with the first opening through the slider, thus cutting off the connection.

[0021] Furthermore, the inflation state in step S4 specifically involves the following: as the ammonia in the fusion chamber and the inflation chamber fuses with the coolant, the piston moves towards the end closer to the base, causing the piston to drive the slider to slide towards the end closer to the base in the second groove; until the slider moves to the end of the slide plate closer to the base, the piston, which continues to move, drives the second opening on the slide plate to connect with the first opening through the slider, and external ammonia is automatically filled into the inflation chamber through the inflation pipe.

[0022] Furthermore, during the inflation state, when the pressure in the fusion chamber and the inflation chamber, and the elastic force of the elastic element are greater than the external pressure, the piston slowly moves away from the base as the ammonia content increases; until the slider moves to the end of the slide plate away from the base, causing the second opening on the slide plate to be misaligned with the first opening and shut off; or, when the pressure in the fusion chamber and the inflation chamber, and the elastic force of the elastic element are equal to or less than the external pressure, the piston remains stationary at the end near the base, and external ammonia continuously enters the fusion chamber and the inflation chamber through the connection between the second opening and the first opening.

[0023] The implementation of this invention has the following beneficial effects:

[0024] This application utilizes a fusion chamber and a gas filling chamber to ensure that the ammonia in the fusion chamber and gas filling chamber is always in contact with and fused with the coolant. This allows the coolant to be automatically and fully fused with the ammonia, resulting in a more uniform ammonia content in the coolant and preventing ammonia waste. The passive ammonia addition device utilizes the physical principle of continuously decreasing two-phase diffusion rate to control the radiation oxygen content in the coolant system pipeline through a self-decelerating ammonia addition strategy. This reduces the generation of gaseous products such as hydrogen and nitrogen, providing a certain degree of protection for the equipment. Furthermore, the total amount of ammonia consumed during operation is also reduced, and the passive design increases the reliability of the device. Attached Figure Description

[0025] To more clearly illustrate the technical solution of the present invention, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0026] In the attached image:

[0027] Figure 1 This is a schematic diagram of a passive ammonia addition device for nuclear reactor coolant provided in an embodiment of the present invention;

[0028] Figure 2 This is a cross-sectional view of a passive ammonia addition device for a nuclear reactor coolant provided in an embodiment of the present invention;

[0029] Figure 3 This is an exploded structural diagram of a passive ammonia loading device for a nuclear reactor coolant provided in an embodiment of the present invention;

[0030] Figure 4 This is a schematic diagram of the structure of the inflation switch provided in an embodiment of the present invention;

[0031] Figure 5 This is a schematic flowchart of a passive ammonia addition method for nuclear reactor coolant provided in an embodiment of the present invention.

[0032] Explanation of markings in the diagram

[0033] Base 1, fusion cavity 11, connecting pipe 12, diffusion chamber 13, inflation seat 2, inflation cavity 21, first opening 22, first slide groove 23, inflation sleeve 24, end cap 25, piston 3, inflation switch 4, slider 41, slide plate 42, damping component 43, second slide groove 44, second opening 45, reset assembly 5, elastic component 51, first limiting component 52, second limiting component 53, coolant system pipeline 6. Detailed Implementation

[0034] To provide a clearer understanding of the technical features, objectives, and effects of this invention, specific embodiments are now described in detail with reference to the accompanying drawings. In the following description, it should be understood that the orientations or positional relationships indicated by terms such as "front," "rear," "upper," "lower," "left," "right," "longitudinal," "horizontal," "vertical," "horizontal," "top," "bottom," "inner," "outer," "head," and "tail" are based on the orientations or positional relationships shown in the accompanying drawings, and are constructed and operated in a specific orientation. They are only for the convenience of describing this technical solution and do not indicate that the device or element referred to must have a specific orientation; therefore, they should not be construed as limitations on this invention.

[0035] It should also be noted that, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "linking," "fixing," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. When an component is referred to as being "on" or "below" another component, the component can be located "directly" or "indirectly" on the other component, or there may be one or more intermediary components. The terms "first," "second," "third," etc., are only for the convenience of describing this technical solution and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first," "second," "third," etc., may explicitly or implicitly include one or more of that feature. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0036] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the invention. However, those skilled in the art will understand that the invention can be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted so as not to obscure the description of the invention with unnecessary detail.

[0037] Please see Figures 1-4According to a first embodiment of the present invention, a passive ammonia charging device for a nuclear reactor coolant includes: a base 1, a charging seat 2, a piston 3, a charging switch 4, and a reset assembly 5. The base 1 has a fusion chamber 11 connected to a coolant system pipeline 6 and incorporating coolant fused with ammonia. The charging seat 2 is mounted on the base 1. The piston 3 is slidably connected to the interior of the charging seat 2, and the charging seat 2 encloses a charging chamber 21 connected to the fusion chamber 11. The charging seat 2 has a first opening 22. The charging switch 4 is located between the first opening 22 and the charging chamber 21, and has a second opening 45. The reset assembly 5 is installed between the piston 3 and the charging seat 2. The ammonia charging device includes a charging state and a shut-off state that switch according to the pressure in the charging chamber 21. In the charging state, the first opening 22 and the second opening 45 are connected to allow ammonia from the charging pipe to enter the charging chamber 21. In the shut-off state, the first opening 22 and the second opening 45 are offset to isolate the charging pipe from the charging chamber 21.

[0038] This application includes a fusion chamber 11 connected to a coolant system pipe 6 within a base 1, into which coolant is fused with ammonia. An inflation seat 2 is mounted on the base 1, and a piston 3 is slidably connected to the interior of the inflation seat 2. The inflation seat 2 and the inflation seat 2 enclose an inflation chamber 21 that communicates with the fusion chamber 11. The inflation seat 2 has a first opening 22. An inflation switch 4 is located between the first opening 22 and the inflation chamber 21, and also has a second opening 45. A reset assembly 5 is installed between the piston 3 and the inflation seat 2. After closing the valves on both sides of the coolant system pipeline 6, the base 1 is installed in the coolant system pipeline 6 through the flange. Then, ammonia is injected into the charging chamber 21 and the fusion chamber 11 through the first opening 22 and the second opening 45. After the charging chamber 21 and the fusion chamber 11 are filled with ammonia, the first opening 22 and the second opening 45 are offset to keep the charging chamber 21, the fusion chamber 11 and the coolant system pipeline 6 sealed. Then, the valves on both sides of the coolant system pipeline 6 are opened to allow the coolant to pass through the fusion chamber 11 inside the base 1. During the passage of the coolant, the coolant will merge with the ammonia in the charging chamber 21 and the fusion chamber 11, causing the ammonia in the charging chamber 21 and the fusion chamber 11 to slowly decrease. As the ammonia decreases, the pressure inside the charging chamber 21 will decrease, causing the piston 3 to slowly move closer to the base 1 as the ammonia content decreases, making the volume of the charging chamber 21 smaller and smaller.

[0039] When piston 3 moves to the lowest end of the inflation seat 2 near the base 1, the first opening 22 and the second opening 45 become connected. Ammonia gas from the outside enters the inflation chamber 21 through the first opening 22 and the second opening 45. The incoming ammonia gas continues to mix with the passing coolant. When the rate of ammonia gas entering is the same as the rate of coolant mixing, piston 3 remains stationary, keeping the first opening 22 and the second opening 45 continuously connected. When the rate of ammonia gas entering is greater than the rate of coolant mixing, the incoming ammonia gas slowly increases the pressure inside the inflation chamber 21, causing piston 3 to slowly move away from the base 1. During the movement of piston 3, the first opening 22 and the second opening 45 remain connected, allowing ammonia gas to continuously enter the inflation chamber 21. When piston 3 moves to the top, the second opening 45 will be offset from the first opening 22 and shut off, thus sealing the fusion chamber 11, the inflation chamber 21, and the coolant system pipe 6 again. After sealing, the ammonia in the fusion chamber 11 and the gas filling chamber 21 continue to fuse with each other as the coolant passes through, repeating the above steps. The entire process is automatic, requiring only an external supply of ammonia connected to the first opening 22. This reduces energy consumption and manufacturing costs. The automatic fusion of ammonia and coolant reduces the possibility of excessive ammonia content in the coolant, avoiding ammonia waste. When the coolant cannot fuse with too much ammonia, the ammonia can be stored in the gas filling chamber 21, further reducing ammonia loss and ensuring a more suitable ammonia content in the coolant.

[0040] The reset component 5 installed between the piston 3 and the gas filling seat 2 can exert a certain pulling force during the upward movement of the piston 3. The pulling force generated is equal to the weight of the piston 3, so that the piston 3 can rise when the fusion rate of ammonia is less than the ammonia introduction rate, thereby improving the sensitivity of the entire device. During the ammonia introduction process, the content of ammonia fused into the coolant is minimized, making its content more uniform and avoiding the waste of ammonia.

[0041] In this process, since the fusion chamber 11 and the charging chamber 21 remain sealed in the cut-off state, as the ammonia and coolant fuse, the piston 3 will also slowly move downward, making the space of the charging chamber 21 smaller and smaller. This allows the ammonia in the fusion chamber 11 and the charging chamber 21 to always be in contact with and fuse with the coolant, making the ammonia content in the coolant more uniform and avoiding the waste of ammonia.

[0042] In some embodiments, the first opening 22 is connected to one end of the inflation pipe, and the other end of the inflation pipe is connected to an ammonia storage tank. Ammonia is pumped into the first opening 22 through the ammonia storage tank and the inflation pipe. When the first opening 22 connects with the second opening 45, the ammonia automatically enters the inflation chamber 21. This allows for the storage of a larger amount of ammonia, enabling the inflation chamber 21 to quickly fill with ammonia. This causes the first opening 22 and the second opening 45 to re-interlock and close, thus preventing a low ammonia content in the coolant. The reaction is faster and suitable for a wider range of applications.

[0043] In some embodiments, a sealing cover can be wrapped around the inflatable base 2, with the interior of the sealing cover connected to the first opening 22 and the inflation tube. The sealing cover is filled with ammonia gas. After the first opening 22 and the second opening 45 are connected, the ammonia gas in the sealing cover enters the inflation chamber 21 through the inflation tube, the first opening 22, and the second opening 45, filling the inflation chamber 21 with ammonia gas. The entire device operates automatically, further saving energy. The sealing cover facilitates installation and ammonia filling, enabling use in remote locations. The sealing cover can be of a flexible structure, making it suitable for more installation environments and ensuring that all the ammonia gas in the sealing cover enters the inflation chamber 21, further reducing ammonia gas loss. The passive ammonia addition device utilizes the physical principle of continuously decreasing two-phase diffusion rate to control the radiation oxygen content in the coolant system pipeline 6 through a self-decelerating ammonia addition strategy. Compared with the one-time ammonia addition strategy, it also has a pH control function to reduce the corrosive environment. Compared with the continuous ammonia addition strategy, it reduces the generation of gaseous products such as hydrogen and nitrogen, which provides a certain degree of protection for the equipment. Furthermore, the total amount of ammonia consumed during operation is also reduced. The passive design also increases the reliability of the device.

[0044] Please see Figures 1-4 In some embodiments, the inflation base 2 is provided with a first slide groove 23, and the inflation switch 4 includes a slider 41 and a slide plate 42. The slider 41 is fixedly installed on one side of the piston 3, and the slide plate 42 is slidably connected in the first slide groove 23. A damping element 43 is provided between the slide plate 42 and the first slide groove 23. A second slide groove 44 is provided on the slide plate 42, and the slider 41 is slidably connected in the second slide groove 44. A second opening 45 is provided on the slide plate 42. When the piston 3 moves, the slider 41 drives the slide plate 42 to move, so that the second opening 45 is connected to or offset from the first opening 22.

[0045] This application provides an inflation base 2 with a first slide groove 23, and an inflation switch 4 including a slider 41 and a slide plate 42. The slider 41 is mounted on the piston 3, and the slide plate 42 is slidably connected in the first slide groove 23. A damping element 43 is provided between the slide plate 42 and the first slide groove 23. A second slide groove 44 is provided on the slide plate 42, and the slider 41 is slidably connected in the second slide groove 44. In the closed state, the slide plate 42 is located at the end of the first slide groove 23 away from the base 1. As the ammonia and coolant fuse, the piston 3 slowly moves towards the base 1. During the movement, it will drive the slider 41 to move together in the second slide groove 44. Since the damping element 43 is provided between the slide plate 42 and the first slide groove 23, the slide plate 42 and the first slide groove 23 will remain relatively stationary. The second opening 45 on the slide plate 42 is always offset from the first opening 22. When the piston 3 drives the slider 41 to move to the end of the second slide groove 44 near the base 1, the piston 3 will drive the slide plate 42 to move towards the base 1 in the first slide groove 23 through the slider 41, overcoming the resistance of the damping element 43, until the second opening 45 on the slide plate 42 is connected to the first opening 22, and the piston 3 remains stationary.

[0046] Afterwards, once the inflation state is reached, external ammonia gas enters the inflation chamber 21 through the second opening 45 and the first opening 22. When the ammonia gas inlet rate is equal to or less than the fusion rate, the piston 3 remains stationary, and the second opening 45 and the first opening 22 remain connected, allowing external ammonia gas to continuously enter the inflation chamber 21, increasing the ammonia content in the coolant. When the ammonia gas inlet rate is greater than the fusion rate, the ammonia content in the inflation chamber 21 increases, causing its pressure to rise. The piston 3 will then slowly move away from the base 1. During this movement, due to the damping element 43 between the slide plate 42 and the first slide groove 23, the piston 3 will only drive the slider 41 to move upward in the second slide groove 44 on the slide plate 42. Throughout this process, the second opening 45 and the first opening 22 remain connected. When slider 41 moves to the end of the second slide groove 44 away from base 1, piston 3 drives slide plate 42 to move away from base 1 on the first slide groove 23 via slider 41. This causes the first opening 22 and the second opening 45 to be misaligned, creating a cut-off state. The ammonia in the gas filling chamber 21 and the fusion chamber 11 will then slowly fuse with the coolant in a closed state, keeping the ammonia content in the coolant uniform. The entire process does not require electrical components for control; it is entirely mechanical, simple in structure, and has a low failure rate. The connection between the first opening 22 and the second opening 45 is controlled by the pressure of the ammonia. It can automatically close to stop the supply of ammonia when there is too much ammonia and automatically open to continue supplying ammonia when there is too little ammonia, further avoiding ammonia waste. It can also automatically balance the ammonia content in the coolant, saving space and manufacturing costs, and reducing labor intensity.

[0047] In some embodiments, a baffle is fixedly installed on the piston 3, and a second opening 45 is provided on the baffle. The baffle is slidably connected to the inflation base 2, so that the surface of the baffle blocks the first opening 22. When the piston 3 moves to the lowest end near the base 1 as ammonia is consumed, the second opening 45 coincides with the first opening 22 and connects, and ammonia continuously enters the inflation chamber 21. When the ammonia inflow rate is greater than the fusion rate, the ammonia content in the inflation chamber 21 will increase, causing its pressure to increase. The piston 3 will drive the baffle to move away from the base 1, and the second opening 45 will be offset from the first opening 22 and cut off. By quickly switching between connection and offset cutoff between the second opening 45 and the first opening 22, the reaction becomes more sensitive, further reducing the waste of ammonia, facilitating manufacturing, and reducing manufacturing costs.

[0048] Please see Figures 1-4 In some embodiments, the damping element 43 is a sealing ring, felt, or interference fit.

[0049] This application utilizes a damping element 43 that can be a sealing ring, felt, or an interference fit. An annular groove can be provided on the sliding plate 42, and the damping element 43, which is a sealing ring or felt, is placed into the annular groove. The annular groove limits the position of the damping element 43, thereby improving sealing performance and connection strength, extending service life, and further reducing ammonia waste.

[0050] When the damping element 43 is a sealing ring, it can improve the seal between the slide plate 42 and the first slide groove 23, prevent the ammonia gas in the inflation chamber 21 from leaking out, further reduce the waste of ammonia gas, and save costs.

[0051] When the damping component 43 is made of felt, the cost is lower and it is easier to install. The felt can reduce the friction between the slide plate 42 and the first slide groove 23, so that the slider 41 can move the slide plate 42 with less effort, further improving the sensitivity.

[0052] The interference fit between the slide plate 42 and the first groove 23 produces a certain damping effect, which is cheaper, has better sealing, and is easier to manufacture.

[0053] Please see Figures 1-4 In some embodiments, the inflatable base 2 includes a hollow inflatable sleeve 24 and an end cap 25, one end of the inflatable sleeve 24 being sealed to the base 1, and the end cap 25 being detachably installed at the other end of the inflatable sleeve 24.

[0054] This application utilizes a hollow inflation sleeve 24 and an end cap 25. One end of the inflation sleeve 24 is sealed to the base 1, and the end cap 25 is detachably installed on the other end of the inflation sleeve 24. The hollow inflation sleeve 24 provides space for ammonia gas to enter, is simple to manufacture, saves manufacturing costs, and facilitates installation. The end cap 25 can be connected to the inflation sleeve 24 via a threaded connection or bolts. Opening the end cap 25 facilitates the installation of the reset assembly 5 and the inflation switch 4 within the inflation sleeve 24, making installation more labor-saving and convenient, and reducing labor intensity.

[0055] Please see Figures 1-4 In some embodiments, the reset assembly 5 includes an elastic element 51 mounted between the end cap 25 and the piston 3.

[0056] This application utilizes the elastic element 51 between the end cap 25 and the piston 3. When the piston 3 moves to the end away from the base 1 via the slider 41 and the slide plate 42, the elastic element 51 is in its original state. As the ammonia and coolant in the inflation chamber 21 fuse, the piston 3 overcomes the elastic force of the elastic element 51 and moves closer to the base 1, causing the elastic element 51 to be stretched. When the piston 3 moves to the end of the first slide groove 23 near the base 1 via the slider 41 and the slide plate 42, the first opening 22 and the second opening 45 are connected, and ammonia enters the inflation chamber 21. The elastic element 51 in the chamber also moves the piston 3 away from the base 1 through the elasticity generated. With the assistance of the piston 3, external ammonia is drawn into the inflation chamber 21, which further improves the efficiency of filling the inflation chamber 21 with ammonia, reduces ammonia loss, makes the ammonia content in the coolant more uniform, and makes the reaction more sensitive.

[0057] Please see Figures 1-4 In some embodiments, the end cap 25 is mounted on the inflatable sleeve 24 via a threaded pair. The reset assembly 5 also includes a first limiting member 52 and a second limiting member 53 that are rotatably connected to the end cap 25 and the piston 3, respectively. The two ends of the elastic member 51 are respectively mounted on the first limiting member 52 and the second limiting member 53.

[0058] This application utilizes a first limiting member 52 and a second limiting member 53, respectively rotatably connected to the end cap 25 and the piston 3, with both ends of the elastic member 51 respectively mounted on the first limiting member 52 and the second limiting member 53. The operator can control the distance between the end cap 25 and the base 1 by rotating the end cap 25 using the threaded connection. Rotating the first limiting member 52 and the second limiting member 53 on the end cap 25 and the piston 3 prevents torsion of the elastic member 51 during rotation, allowing the operator to rotate the end cap 25 more smoothly. By controlling the distance between the end cap 25 and the base 1, the stretching length of the elastic member 51 can be changed, thereby altering the elastic force exerted by the elastic member 51 on the piston 3. After the piston 3 moves multiple times, the elasticity of the elastic member 51 weakens. The operator can then rotate the end cap 25, causing the elastic member 51 to be stretched between the piston 3 and the end cap 25, thus increasing the elastic force of the elastic member 51 on the piston 3, extending its service life, and facilitating adjustment.

[0059] By changing the distance between the end cap 25 and the piston 3, the pressure change inside the inflation chamber 21 can also be changed, thereby adjusting the fusion rate of ammonia and coolant in the inflation chamber 21. This makes it suitable for more operating environments and allows for more flexible adjustment.

[0060] Please see Figures 1-4 In some embodiments, the base 1 includes at least one connecting pipe 12 and a diffusion chamber 13. The two ends of the connecting pipe 12 are respectively connected to the coolant system pipeline 6 to receive coolant and output it after the coolant and ammonia are mixed. The diffusion chamber 13 is disposed between the inlet and outlet of the connecting pipe 12 to mix the received ammonia with the coolant.

[0061] This application utilizes at least one connecting pipe 12 and a diffusion chamber 13. The two ends of the connecting pipe 12 are connected to the coolant system pipeline 6 to receive coolant, which is then discharged after merging with ammonia. The diffusion chamber 13 is positioned between the inlet and outlet of the connecting pipe 12 to merge the incoming ammonia with the coolant. The connecting pipe 12 facilitates the installation of the entire ammonia charging device within the coolant system pipeline 6, improving installation efficiency and sealing with the base 1. The diffusion chamber 13 expands the contact area between the ammonia and the passing coolant, allowing the passing coolant to quickly and fully merge with the ammonia, thus improving merging efficiency.

[0062] Please see Figures 1-4 In some embodiments, the diameter of the fusion cavity 11 is larger than the diameter of the connecting pipe 12. The cross-sectional area of ​​the fusion cavity 11 on the side closer to the inflation seat 2 is smaller than the cross-sectional area on the side farther from the inflation seat 2.

[0063] In this application, the diameter of the fusion chamber 11 is larger than the diameter of the connecting pipe 12. When the coolant passes through the fusion chamber 11, the area can be expanded and the flow rate slowed down, allowing the ammonia in the gas filling chamber 21 and the fusion chamber 11 to fuse more quickly and fully with the ammonia, further improving the fusion efficiency. The ammonia in the coolant is also more uniform.

[0064] This application achieves spontaneous decay of the ammonia addition rate by using the physical principle that the mass transfer rate at the phase interface gradually decreases during two-phase diffusion. The conical fusion chamber 11 increases stability through a negative feedback mechanism that reduces the gas-liquid contact area due to the rise of the coolant liquid level, thereby improving the stability and uniformity of the fusion of ammonia and coolant.

[0065] Please see Figures 1-5 The present invention also provides a passive ammonia addition method for nuclear reactor coolant, comprising the following steps:

[0066] S1. Connect the aforementioned passive ammonia addition device for the nuclear reactor coolant to the coolant system pipeline 6;

[0067] S2. Connect one end of the inflation tube to the first opening 22, and connect the other end of the inflation tube to the outside ammonia gas.

[0068] S3. Ammonia gas is automatically filled into the inflation chamber 21 through the inflation tube. The pressure difference causes the piston 3 to move the slide plate 42 away from the base 1 via the slider 41, thus reaching the cut-off state.

[0069] S4. As the ammonia in the inflation chamber 21 merges with the coolant in the fusion chamber 11, the pressure difference causes the piston 3 to move the slide plate 42 to one end near the base 1 via the slider 41, thus achieving the inflation state.

[0070] S5. Repeat steps S3 and S4 above until all the external ammonia is consumed, then add ammonia again.

[0071] This application involves the following steps: Step S1. Connecting the aforementioned passive ammonia charging device for the nuclear reactor coolant to the coolant system pipeline 6; Step S2. Connecting one end of the charging pipe to the first opening 22 and the other end of the charging pipe to external ammonia gas; Step S3. Automatically filling the charging chamber 21 with ammonia gas through the charging pipe, using the pressure difference to move the piston 3, via the slider 41, to the end away from the base 1, reaching the cut-off state; Step S4. As the ammonia gas in the charging chamber 21 merges with the coolant in the fusion chamber 11, using the pressure difference to move the piston 3, via the slider 41, to the end closer to the base 1, reaching the charging state; Step S5. Repeating steps S3 and S4 until all the external ammonia gas is consumed, and then adding ammonia gas again. It can make the ammonia content in the coolant more uniform, avoid ammonia waste, control the radiation oxygen content in the coolant system pipeline through the self-deceleration ammonia addition strategy, reduce the generation of gaseous products such as hydrogen and nitrogen, play a certain role in protecting the equipment, and reduce the total amount of ammonia consumed during operation. The passive design also increases the reliability of the entire ammonia addition process.

[0072] Please see Figures 1-5 In some embodiments, the cutoff state in step S3 specifically means that the ammonia gas filled into the inflation chamber 21 will move the piston 3 away from the base 1, causing the piston 3 to drive the slider 41 to slide in the second groove 44 away from the base 1; until the slider 41 moves to the end of the slide plate 42 away from the base 1, the piston 3, which continues to move, will drive the second opening 45 on the slide plate 42 to be misaligned with the first opening 22 through the slider 41 to cut off.

[0073] This application allows the piston 3 to drive the slider 41 to slide in the second groove 44 towards the end away from the base 1, so that the piston 3 has a certain stroke to move towards the end away from the base 1. This allows the gas filling chamber 21 to store more ammonia gas, and there is enough ammonia gas content to mix with the coolant, thereby making the ammonia gas content in the coolant more uniform and avoiding the waste of ammonia gas.

[0074] Please see Figures 1-5 In some embodiments, the inflation state in step S4 is specifically as follows: as the ammonia in the fusion chamber 11 and the inflation chamber 21 fuses with the coolant, the piston 3 moves towards the end closer to the base 1, causing the piston 3 to drive the slider 41 to slide towards the end closer to the base 1 in the second slide groove 44; until the slider 41 moves to the end of the slide plate 42 closer to the base 1, the piston 3, which continues to move, drives the second opening 45 on the slide plate 42 to connect with the first opening 22 through the slider 41, and the external ammonia is automatically filled into the inflation chamber 21 through the inflation pipe.

[0075] This application utilizes a passive ammonia addition device where piston 3 slowly moves towards base 1 as the ammonia content decreases. This device leverages the physical principle of continuously decreasing two-phase diffusion rates. Compared to a one-time ammonia addition strategy, it also features pH control to mitigate corrosive environments. Compared to a continuous ammonia addition strategy, it produces fewer hydrogen, nitrogen, and other gaseous byproducts, and the total amount of ammonia consumed during operation is also reduced. The passive design also increases the reliability of the entire device. The entire process reduces energy consumption and conserves resources.

[0076] Please see Figures 1-5 In some embodiments, when the pressure of the fusion chamber 11 and the inflation chamber 21 and the elastic force of the elastic element 51 are greater than the external pressure in the inflation state, the piston 3 slowly moves away from the base 1 as the ammonia content increases; until the slider 41 moves to the end of the slide plate 42 away from the base 1, causing the second opening 45 on the slide plate 42 to be misaligned with the first opening 22 and cut off.

[0077] Alternatively, when the pressure in the fusion chamber 11 and the inflation chamber 21 and the elastic force of the elastic element 51 are equal to or less than the external pressure, the piston 3 remains stationary at the end near the base 1, and external ammonia gas continuously enters the fusion chamber 11 and the inflation chamber 21 through the connection between the second opening 45 and the first opening 22.

[0078] This application utilizes piston 3 to connect or disconnect the second opening 45 from the first opening 22 based on the ammonia content in the filling chamber 21. This allows for automatic closure to stop ammonia flow when there is excessive ammonia, and automatic opening to continuously flow ammonia when there is insufficient ammonia, further preventing ammonia waste. It also allows the ammonia content in the coolant to automatically reach equilibrium, saving space and manufacturing costs, and reducing labor intensity.

[0079] It is understood that the above embodiments only illustrate preferred embodiments of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can freely combine the above technical features without departing from the concept of the present invention, and can also make several modifications and improvements, all of which fall within the protection scope of the present invention. Therefore, all equivalent transformations and modifications made with respect to the scope of the claims of the present invention should fall within the scope of the claims of the present invention.

Claims

1. A passive ammonia addition device for nuclear reactor coolant, characterized in that, include: Base (1), inflation seat (2), piston (3), inflation switch (4) and reset assembly (5); The base (1) is provided with a fusion chamber (11) that is connected to the coolant system pipeline (6) and connected to the coolant that is fused with ammonia. The air filling seat (2) is provided on the base (1). The piston (3) is slidably connected inside the air seat (2), and the air seat (2) surrounds an air chamber (21) that communicates with the fusion cavity (11). The air seat (2) is provided with a first opening (22). The inflation switch (4) is located between the first opening (22) and the inflation chamber (21), and is provided with a second opening (45). The reset assembly (5) is installed between the piston (3) and the air inlet (2); The ammonia addition device includes a filling state and a shut-off state that are switched according to the pressure in the filling chamber (21); In the inflated state, the first opening (22) is connected to the second opening (45) to allow ammonia gas from the inflation tube to be introduced into the inflation chamber (21). In the cut-off state, the first opening (22) and the second opening (45) are offset and cut off to isolate the inflation tube from the inflation chamber (21). The inflation seat (2) is provided with a first slide groove (23), and the inflation switch (4) includes: a slider (41) and a slide plate (42); the slider (41) is fixedly installed on one side of the piston (3); the slide plate (42) is slidably connected in the first slide groove (23), and a damping element (43) is provided between the slide plate (42) and the first slide groove (23); a second slide groove (44) is opened on the slide plate (42), and the slider (41) is slidably connected in the second slide groove (44); The second opening (45) on the slide plate (42) is moved by the slider (41) when the piston (3) moves, so that the second opening (45) is connected to or offset from the first opening (22); The inflatable base (2) includes a hollow inflatable sleeve (24) and an end cap (25). One end of the inflatable sleeve (24) is sealed to the base (1). The end cap (25) is detachably installed at the other end of the inflatable sleeve (24). The reset assembly (5) is installed between the end cap (25) and the piston (3).

2. The passive ammonia addition device for nuclear reactor coolant according to claim 1, characterized in that, The damping element (43) is a sealing ring, felt, or interference fit.

3. The passive ammonia addition device for nuclear reactor coolant according to claim 1, characterized in that, The reset assembly (5) includes an elastic element (51) installed between the end cap (25) and the piston (3).

4. The passive ammonia addition device for nuclear reactor coolant according to claim 3, characterized in that, The end cap (25) is installed on the air sleeve (24) by a threaded pair. The reset assembly (5) also includes a first limiting member (52) and a second limiting member (53) that are rotatably connected to the end cap (25) and the piston (3), respectively. The two ends of the elastic member (51) are respectively installed on the first limiting member (52) and the second limiting member (53).

5. The passive ammonia addition device for nuclear reactor coolant according to claim 3, characterized in that, The base (1) includes at least one connecting pipe (12) and a diffusion chamber (13). The two ends of the connecting pipe (12) are respectively connected to the coolant system pipeline (6) to receive the coolant and output the coolant after it is mixed with the ammonia. The diffusion chamber (13) is located between the inlet and outlet of the connecting pipe (12) to fuse the incoming ammonia gas with the coolant.

6. The passive ammonia addition device for nuclear reactor coolant according to claim 5, characterized in that, The diameter of the fusion cavity (11) is larger than the diameter of the connecting pipe (12); the cross-sectional area of ​​the fusion cavity (11) on the side closer to the inflatable seat (2) is smaller than the cross-sectional area on the other side away from the inflatable seat (2).

7. A method for passively adding ammonia to a nuclear reactor coolant, characterized in that, Includes the following steps: S1. Connect the passive ammonia addition device for the nuclear reactor coolant according to any one of claims 1-6 to the coolant system pipeline (6); S2. Connect one end of the inflation tube to the first opening (22), and connect the other end of the inflation tube to the outside ammonia gas; S3. Ammonia gas is automatically filled into the inflation chamber (21) through the inflation tube. The pressure difference causes the piston (3) to move the slide plate (42) away from the base (1) through the slider (41) to reach the cut-off state. S4. As the ammonia in the inflation chamber (21) merges with the coolant in the fusion chamber (11), the piston (3) is moved by the slider (41) to the end near the base (1) by the pressure difference, thus achieving the inflation state. S5. Repeat steps S3 and S4 above until all the ammonia in the outside is consumed, then add ammonia again; or continuously fill the enclosed space with ammonia.

8. The passive ammonia addition method for nuclear reactor coolant according to claim 7, characterized in that, The cutoff state in step S3 specifically means that the ammonia gas filled into the inflation chamber (21) will move the piston (3) away from the base (1), causing the piston (3) to drive the slider (41) to slide away from the base (1) in the second groove (44); until the slider (41) moves to the end of the slide plate (42) away from the base (1), the piston (3) that continues to move will drive the second opening (45) on the slide plate (42) to be misaligned with the first opening (22) through the slider (41) and cut off.

9. The passive ammonia addition method for nuclear reactor coolant according to claim 8, characterized in that, The inflation state in step S4 is specifically as follows: as the ammonia in the fusion chamber (11) and the inflation chamber (21) fuses with the coolant, the piston (3) moves toward the end closer to the base (1), causing the piston (3) to drive the slider (41) to slide toward the end closer to the base (1) in the second groove (44); until the slider (41) moves to the end of the slide plate (42) closer to the base (1), the piston (3) continues to move and drives the second opening (45) on the slide plate (42) to connect with the first opening (22) through the slider (41), and external ammonia is automatically filled into the inflation chamber (21) through the inflation pipe.

10. The passive ammonia addition method for nuclear reactor coolant according to claim 9, characterized in that, In the inflation state, when the pressure of the fusion chamber (11) and the inflation chamber (21) and the elastic force of the elastic element (51) are greater than the external pressure, the piston (3) slowly moves away from the base (1) as the ammonia content increases; until the slider (41) moves to the end of the slide plate (42) away from the base (1), causing the second opening (45) on the slide plate (42) to be misaligned with the first opening (22) and cut off; Alternatively, when the pressure in the fusion chamber (11) and the inflation chamber (21) and the elastic force of the elastic element (51) are equal to or less than the external pressure, the piston (3) remains stationary at the end near the base (1), and external ammonia gas continuously enters the fusion chamber (11) and the inflation chamber (21) through the communication between the second opening (45) and the first opening (22).

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