A passive containment cooling system driven by gas injection principle and chemical reaction

Abstract

This invention proposes a passive containment cooling system driven by gas jet principle and chemical reaction, belonging to the field of nuclear reaction. It addresses the problems of poor reliability and easy failure of existing active containment spraying measures. It includes a containment with air cooling channels around its perimeter; a spraying device for discharging refrigerant to cool the containment; at least one sealed water tank, with the outlet of each tank connected to the inlet of the spraying device; a chemical dosing device connected to the sealed water tank, used to add chemicals to the tank when the containment pressure increases; the chemicals react to increase the pressure inside the sealed water tank and force water into the spraying device; a gas release device, with its inlet connected to the outlet of the sealed water tank via a switch, and the outlet located within the air cooling channels; and a controller electrically connected to both the chemical dosing device and the gas release device. It is primarily used for containment cooling.

Description

Technical Field

[0001] This invention belongs to the field of nuclear reaction, and in particular relates to a passive containment cooling system driven by gas ejection principle and chemical reaction. Background Technology

[0002] Following a severe accident in a reactor, the containment structure may experience a rise in temperature and pressure, and could even fail. Maintaining the integrity of the containment structure can significantly reduce the release of radioactive materials into the external environment, and is a crucial objective of severe accident mitigation strategies. In severe accidents, such as those originating from a large breach, a large amount of high-temperature steam is typically released into the containment structure, causing a rise in temperature and pressure. Developing effective methods to remove heat from the containment structure is essential for maintaining its integrity.

[0003] Currently, nuclear power plants mostly employ active containment spray systems to reduce temperature and pressure within the containment during accidents. However, a major problem they face is that the spray pumps require AC power during operation, which undoubtedly increases the risk of spray system failure due to power loss. This also places stringent demands on the reliability of the power system. To address the main problems with current containment cooling systems used in nuclear power plants, a novel passive containment cooling system is designed. Summary of the Invention

[0004] In view of this, the present invention aims to propose a passive containment cooling system driven by gas jet principle and chemical reaction to solve the problem of poor reliability and easy failure of existing active containment spray measures.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a passive containment cooling system driven by gas injection principle and chemical reaction, comprising:

[0006] The containment vessel is equipped with air cooling channels on its periphery;

[0007] The spray system is used to output refrigerant to cool the containment vessel;

[0008] At least one sealed water tank is provided, and the outlet of each sealed water tank is connected to the inlet of the spray device;

[0009] A dosing device is connected to the sealed water tank and is used to add chemicals into the sealed water tank when the pressure of the containment increases. The chemicals are used to increase the pressure inside the sealed water tank after the reaction and to force the water in the sealed water tank into the spraying device.

[0010] The gas discharge device has an inlet end connected to the outlet end of a sealed water tank via a switch, and the outlet end is located inside the air cooling channel.

[0011] The controller is electrically connected to both the dosing device and the gas release device.

[0012] Furthermore, the spraying device includes a water storage tank and a spraying device, wherein the water outlet of the sealed water tank is connected to the water inlet of the water storage tank, and the water outlet of the water storage tank is equipped with a spraying device.

[0013] Furthermore, the spraying device is a spray head.

[0014] Furthermore, the dosing device includes a dispensing device and a triggering device. The dispensing device has at least two isolated storage tanks. Both the triggering device and the dosing device are electrically connected to the controller. The triggering device transmits a signal indicating high containment pressure to the controller, which then controls the dispensing device to dispense the agent in response to the triggering device.

[0015] Furthermore, the dispensing device is an electric valve.

[0016] Furthermore, the triggering device is a pressure sensor.

[0017] Furthermore, the switch is a second shut-off valve.

[0018] Furthermore, the sealed water tank is connected to the spraying device via a pipeline, and a check valve and a first shut-off valve are sequentially installed on the pipeline.

[0019] Furthermore, an ultrasonic oscillator is provided at the outlet end of the gas discharge device, and the ultrasonic oscillator is electrically connected to the controller.

[0020] Furthermore, the gas discharge device is a gas nozzle.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] 1. This system uses a large amount of gas generated by a chemical reaction to provide driving force, which forces the water in the sealed water tank into the spray device to stabilize its liquid transport, spray and cool the containment shell, and then uses air jet principle to cool the containment shell in a timely manner to remove the heat inside the containment.

[0023] 2. This system takes into account the specific application environment of the PCCS system, the conditions and states during an accident, and makes full use of the operating characteristics of nuclear power plants;

[0024] 3. This system reduces the installation of active equipment such as pumps. Based on the existing containment structure, by setting up a water tank around the containment, the use of active mechanical equipment such as pumps is avoided, which reduces the failure rate of the equipment, reduces the control of active equipment such as pumps, effectively reduces the possibility of human error, simplifies the design of the measurement and control system, and has high reliability.

[0025] 4. This system can generate ultrasonic waves of appropriate frequency in the gas diversion device by setting an acoustic oscillator, which will cause the gas to vibrate, thereby increasing the gas flow and speed, thus achieving a larger gas flow rate. Attached Figure Description

[0026] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0027] Figure 1 This is a schematic diagram of a passive containment cooling system driven by gas injection principle and chemical reaction as described in this invention.

[0028] 1. Sealed water tank; 2. Dosing device; 3. Spraying device; 4. Water storage tank; 5. Spraying equipment; 6. Dispensing device; 7. Triggering device; 8. Containment vessel; 9. Pipeline; 10. Check valve; 11. First shut-off valve; 12. Gas release device; 13. Second shut-off valve; 14. Air cooling channel; 15. Ultrasonic oscillator. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other, and the described embodiments are only some embodiments of the present invention, not all embodiments.

[0030] It should be noted that the descriptions of "left," "right," "left side," "right side," "upper part," "lower part," "top," and "bottom" in this invention are defined based on the orientation or positional relationships shown in the accompanying drawings. They are merely for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the described structure must be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0031] In the description of this invention, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" 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 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 invention based on the specific circumstances.

[0032] Referring to the accompanying drawings, this embodiment describes a passive containment cooling system driven by gas injection and chemical reaction, comprising:

[0033] The containment vessel 8 has air cooling channels 14 on its periphery. By providing air cooling channels 14, airflow can be enhanced, thereby improving the cooling effect on the containment vessel 8. The air cooling channels 14 can be formed by providing another shell on the outside of the containment vessel 8.

[0034] Spray device 3 is used to output refrigerant to cool containment 8;

[0035] At least one sealed water tank 1 is provided, and the outlet of each sealed water tank 1 is connected to the inlet of the spray device 3. The sealed water tank 1 can be specifically arranged around the periphery of the containment vessel 8, and can play a role in stabilizing the overall ambient temperature of the containment vessel 8 when not in use. The outlet of the sealed water tank 1 is located at the lower part of the sealed water tank 1, so that as much water as possible can be discharged during drainage.

[0036] The dosing device 2 is connected to the sealed water tank 1 and is used to add chemicals into the sealed water tank 1 when the pressure of the containment 8 increases. The chemicals are used to increase the pressure in the sealed water tank 1 after the reaction and to force the water in the sealed water tank 1 into the spraying device 3.

[0037] The gas discharge device 12 has its inlet end connected to the outlet end of the sealed water tank 1 via a switch, and its outlet end is located in the air cooling channel 14.

[0038] The controller is electrically connected to both the dosing device 2 and the gas release device 12.

[0039] In this embodiment, the spraying device 3 includes a water storage tank 4 and a spraying device 5. The water outlet of the sealed water tank 1 is connected to the water inlet of the water storage tank 4, and the water outlet of the water storage tank 4 is equipped with the spraying device 5.

[0040] In this embodiment, the spraying device 5 is a spray head. A spray head from an existing spray cooling system can be used.

[0041] In this embodiment, the dosing device 2 includes a dispensing device 6 and a triggering device 7. The dispensing device 6 has at least two isolated storage tanks. Both the triggering device 7 and the dosing device 2 are electrically connected to a controller. The triggering device 7 transmits a signal indicating high pressure on the containment vessel 8 to the controller, which then controls the dispensing device 6 to dispense the reagent in response to the triggering device 7. The reagent can be sodium bicarbonate or sodium carbonate plus an acid such as hydrochloric acid or acetic acid. Sodium carbonate and acetic acid are readily available and can be preferred; however, they are not exhaustively listed here. Any reagent that can react in water and cause gas expansion without affecting the system can be selected.

[0042] In this embodiment, the dispensing device 6 is a housing with an electric valve. Existing technology can be used for the electric valve; for example, a ball screw controlling two doors to open and close in a parallel manner can meet the requirements of this system. No exhaustive list is provided here; any gate that can fulfill the dispensing function can be used in this system.

[0043] In this embodiment, the triggering device 7 is a pressure sensor. The pressure sensor detects the pressure on the containment vessel 8 and transmits the pressure signal to the controller, which then controls the electric valve to operate.

[0044] In this embodiment, the switch is a second shut-off valve 13. The second shut-off valve 13 can prevent water backflow and ensure that water flows in one direction only.

[0045] In this embodiment, the sealed water tank 1 is connected to the spray device 3 via a pipeline 9, and a check valve 10 and a first shut-off valve 11 are sequentially installed on the pipeline 9.

[0046] In this embodiment, an ultrasonic oscillator 15 is provided at the outlet end of the gas discharge device 12, and the ultrasonic oscillator 15 is electrically connected to the controller. The ultrasonic oscillator 15 can generate ultrasonic waves of appropriate frequency in the gas discharge device 12, causing the gas to vibrate, thereby increasing the gas flow and velocity, and thus increasing the gas's entrainment effect on the back pressure zone gas in the air cooling channel 14, thereby enhancing the gas flow effect and bringing a stronger cooling effect.

[0047] In this embodiment, the gas discharge device 12 is a gas nozzle. Any existing gas nozzle capable of unidirectional gas discharge can be used.

[0048] When the pressure in the containment vessel 8 is too high, the triggering device 7 will transmit the pressure signal to the controller. The controller will then control the dosing device 2 to add the reagent into the sealed water tank 1 for reaction. The increased gas pressure will cause water to flow from the sealed water tank 1 through the check valve 10 and the first shut-off valve 11 of the pipeline 9 into the water storage tank 4 of the spraying device 3. The water will then be sprayed through the spraying equipment 5 of the water storage tank 4 to spray the containment vessel 8 located below the spraying equipment 5, thereby cooling the containment vessel 8.

[0049] After the water in the sealed water tank 1 is completely drained, the controller opens the second shut-off valve 13 and closes the pipeline 9. This allows the remaining gas to be ejected from the gas release device 12, entraining the gas in the back pressure zone and creating a strong gas flow effect in the air cooling channel 14, helping the containment vessel 8 continue to cool. The exact time when the water in the sealed water tank 1 is completely drained can be determined based on empirical data derived from the drug dosage and reaction rate, which is then input into the controller. This allows the controller to control the timing of opening the second shut-off valve 13 and closing the pipeline 9.

[0050] The controllers, sensors, and control programs mentioned above are all existing technologies and will not be elaborated upon here.

[0051] The embodiments of the present invention disclosed above are merely illustrative of the invention. These embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention.

Claims

1. A passive containment cooling system driven by gas jet principle and chemical reaction, characterized in that, include: The containment vessel (8) has air cooling channels (14) on its periphery; A spray device (3) is used to output refrigerant to cool the containment vessel (8); At least one sealed water tank (1) is provided, and the outlet end of each sealed water tank (1) is connected to the inlet end of the spray device (3); The dosing device (2) is connected to the sealed water tank (1) and is used to add chemicals into the sealed water tank (1) when the pressure of the containment vessel (8) increases. The chemicals are used to increase the pressure inside the sealed water tank (1) after the reaction and to force the water in the sealed water tank (1) into the spraying device (3). The gas discharge device (12) has its inlet end connected to the outlet end of the sealed water tank (1) via a switch, and the outlet end is located in the air cooling channel (14). The controller is electrically connected to both the dosing device (2) and the gas release device (12).

2. The passive containment cooling system driven by gas jet principle and chemical reaction according to claim 1, characterized in that: The spraying device (3) includes a water storage tank (4) and a spraying device (5). The outlet of the sealed water tank (1) is connected to the inlet of the water storage tank (4), and the outlet of the water storage tank (4) is equipped with the spraying device (5).

3. The passive containment cooling system driven by gas injection principle and chemical reaction according to claim 2, characterized in that: The spraying device (5) is a spray head.

4. The passive containment cooling system driven by gas jet principle and chemical reaction according to claim 1, characterized in that: The dosing device (2) includes a dispensing device (6) and a triggering device (7). The dispensing device (6) has at least two isolated storage tanks. Both the triggering device (7) and the dosing device (2) are electrically connected to the controller. The triggering device (7) transmits a signal indicating high pressure of the containment vessel (8) to the controller. The controller responds to the triggering device (7) and controls the dispensing device (6) to dispense the agent.

5. A passive containment cooling system driven by gas jet principle and chemical reaction according to claim 4, characterized in that: The dispensing device (6) is an electric valve.

6. A passive containment cooling system driven by gas jet principle and chemical reaction according to claim 4, characterized in that: The triggering device (7) is a pressure sensor.

7. A passive containment cooling system driven by gas jet principle and chemical reaction according to claim 1, characterized in that: The switch is the second shut-off valve (13).

8. A passive containment cooling system driven by gas jet principle and chemical reaction according to claim 1, characterized in that: The sealed water tank (1) is connected to the spray device (3) via a pipeline (9), and a check valve (10) and a first shut-off valve (11) are sequentially installed on the pipeline (9).

9. A passive containment cooling system driven by gas jet principle and chemical reaction according to any one of claims 1-8, characterized in that: An ultrasonic oscillator (15) is provided at the outlet end of the gas discharge device (12), and the ultrasonic oscillator (15) is electrically connected to the controller.

10. A passive containment cooling system driven by gas injection principle and chemical reaction according to claim 9, characterized in that: The gas discharge device (12) is a gas nozzle.

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