Passive reactor core and containment cooling and heat extraction system and method

Abstract

The invention discloses a passive reactor core and containment cooling and heat extraction system which comprises a steam generator, an air cooling heat exchanger, an exhaust unit and a water cooling heat exchanger, the primary side of the steam generator is communicated with the reactor pressure vessel; a secondary side outlet of the steam generator communicates with a heat source channel inlet of the air-cooling heat exchanger through a first pipeline; a heat source channel outlet of the air-cooling heat exchanger communicates with a heat source channel inlet of the water-cooling heat exchanger; a heat source channel of the air-cooling heat exchanger communicates with an inlet of the exhaust unit; a heat source channel outlet of the water-cooling heat exchanger is communicated with a secondary side inlet of the steam generator through a second pipeline; the interior of the containment is communicated with the first pipeline through a third pipeline; and the interior of the containment is communicated with the second pipeline through a fourth pipeline. The invention also discloses a method for cooling and heat removal of the reactor core and the containment. The system has the beneficial effects that the reactor core heat removal and the containment cooling are integrated, so that the number of system equipment is greatly reduced, and the occupation of total resources is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of containment heat removal, and in particular to a passive core and containment cooling and heat removal system and method. Background Art

[0002] Nuclear power plants are commonly equipped with passive residual heat removal systems to remove decay heat from the reactor core during transient conditions or accidents, when normal heat removal fails. Existing passive residual heat removal systems consist of an elevated water tank outside the containment vessel and a heat exchanger within the tank. Steam condenses within the heat exchanger, and the system establishes a natural circulation system to remove heat by leveraging the system's height difference and the density difference between the vapor and liquid phases. The operating time of the passive residual heat removal system is closely related to the water level in the cooling water tank. To maintain long-term heat removal operation, the cooling water tank often requires water replenishment.

[0003] To address the long-term heat removal after a LOCA (Local Containment Accident) accident, existing passive containment cooling solutions include external-tube condensation and internal-tube condensation. The open natural circulation passive containment heat removal system based on external-tube condensation employs an elevated water tank outside the containment and a cooling heat exchanger inside the containment. During an accident, high-temperature, high-pressure steam condenses and exchanges heat in the cooling heat exchanger. The system achieves natural circulation by leveraging the height difference between the cooling water tank and the heat exchanger, as well as the density of the medium in the ascending and descending sections. The passive containment cooling system based on internal condensation employs an external cooling water tank and a submerged heat exchanger within the cooling water tank. The heat exchanger inlet is connected to the containment, and the heat exchanger outlet is equipped with a bottom condensate outlet and a side exhaust outlet. During an accident, steam from the containment dry well enters the condenser through the steam inlet pipe, condenses at the pipe end, and the condensate flows through a discharge line into the gravity-driven cooling pool (GDCS). Given that the medium on the heat exchanger tube side is a steam-air mixture, the presence of air significantly degrades the system's heat transfer efficiency, making it necessary to promptly discharge non-condensable gases from the heat exchanger.

[0004] However, existing nuclear power plants have separate passive residual heat removal systems and passive containment cooling systems, with no shared equipment. This results in a high overall resource footprint and requires significant space. Therefore, it is necessary to comprehensively optimize both the passive containment cooling system and the passive residual heat removal system to reduce overall resource usage and improve the system's heat removal capacity through optimized design. Summary of the Invention

[0005] The purpose of the present invention is to provide a passive core and containment cooling and heat removal system and method to address the deficiencies of the prior art, aiming to solve the problem of large resource occupation in the prior art.

[0006] The technical solution adopted by the present invention is: a passive core and containment cooling and heat removal system, including a steam generator, an air-cooled heat exchanger, an exhaust unit and a water-cooled heat exchanger; The steam generator is arranged in the containment vessel, and the primary side of the steam generator is connected to the interior of the pressure vessel of the reactor through a pipeline; the secondary side outlet of the steam generator is connected to the inlet of the heat source channel of the air-cooled heat exchanger outside the containment vessel through a first pipeline, a first excess solenoid valve is provided on the first pipeline, and the first pipeline is connected to the steam main pipe; the heat source channel outlet of the air-cooled heat exchanger is connected to the heat source channel inlet of the water-cooled heat exchanger; the heat source channel of the air-cooled heat exchanger is connected to the inlet of the exhaust unit through a pipeline, and the outlet of the exhaust unit is connected to the atmosphere; the heat source channel outlet of the water-cooled heat exchanger is connected to the secondary side inlet of the steam generator through a second pipeline, a second excess solenoid valve and a check valve are provided on the second pipeline, and the second pipeline is connected to the water supply main pipe; The interior of the containment shell is connected to the first pipeline through a third pipeline, and a first cooling isolation valve is arranged on the third pipeline; the interior of the containment shell is connected to the second pipeline through a fourth pipeline, and a second cooling isolation valve is arranged on the fourth pipeline.

[0007] According to the above solution, the air-cooled heat exchanger is arranged in the air-cooled tower; the water-cooled heat exchanger is arranged in the cooling water tank.

[0008] According to the above solution, the air-cooled heat exchanger and the water-cooled heat exchanger are both arranged outside the containment vessel.

[0009] According to the above solution, the fourth pipeline is connected to the fifth pipeline, and the fifth pipeline penetrates into the interior of the containment vessel and is connected to the interior of the core.

[0010] According to the above solution, a core water injection isolation valve is provided on the fifth pipeline.

[0011] According to the above scheme, the exhaust unit includes an air collecting tank, a filtering and exhausting device and an exhaust pipeline; the air collecting tank is connected to the heat source channel of the air-cooled heat exchanger through the sixth pipeline, and a first automatic air exhaust valve is arranged on the sixth pipeline; the outlet of the air collecting tank is connected to the inlet of the filtering and exhausting device through the seventh pipeline, and the outlet of the filtering and exhausting device is connected to the outside atmosphere through the exhaust pipeline.

[0012] According to the above solution, the seventh pipeline is provided with an automatic exhaust valve; and the exhaust pipeline is provided with a discharge isolation valve.

[0013] According to the above scheme, the inlet of the heat source channel of the water-cooled heat exchanger is provided with a first bypass pipeline connected to the sixth pipeline, and the first bypass pipeline is equipped with a second automatic air exhaust valve; the outlet of the heat source channel of the water-cooled heat exchanger is provided with a second bypass pipeline connected to the sixth pipeline, and the second bypass pipeline is equipped with a third automatic air exhaust valve.

[0014] The present invention also discloses a method for cooling the containment based on the passive core and containment cooling and heat removal system as described above, the method comprising: When a LOCA accident occurs in the containment, the first cooling isolation valve and the second cooling isolation valve are opened remotely or locally, and the steam in the containment enters the air-cooled heat exchanger, exchanges heat with the atmosphere outside the air-cooled heat exchanger, and then enters the water-cooled heat exchanger to exchange heat with the cooling water, thereby extracting the heat from the containment. During system operation, when gas is generated in the air-cooled heat exchanger and the water-cooled heat exchanger, the automatic air exhaust valve on the corresponding pipeline will automatically open when it detects air, and discharge the air into the gas collecting tank; when the pressure in the gas collecting tank rises to the set pressure, the automatic exhaust valve between the gas collecting tank and the filter discharge device will open, and the discharge isolation valve will be opened at the same time to filter the air in the gas collecting tank and discharge it.

[0015] The present invention further discloses a method for removing heat from the core based on the passive core and containment cooling and heat removal system as described above, the method comprising: When a power outage occurs in the entire plant and the reactor is shut down, the first and second residual solenoid valves are de-energized and automatically open, and the core heat is transferred to the secondary side of the steam generator through the primary natural circulation; the steam on the secondary side of the steam generator enters the air-cooled heat exchanger due to the natural circulation caused by the density difference, exchanges heat with the atmosphere outside the air-cooled heat exchanger, and then enters the water-cooled heat exchanger to exchange heat with the cooling water, bringing the primary circuit heat to the atmosphere and the cooling water tank, thereby achieving cooling and pressure reduction of the primary circuit.

[0016] The beneficial effects of the present invention are: 1) The present invention adopts an in-tube condensation scheme that combines air cooling and water cooling in series, with air cooling first and water cooling later, integrating the core heat removal and containment cooling into a single design. By switching valves, the entire system can serve as both a passive residual heat removal system for removing heat from the reactor core and a passive containment cooling system for cooling the containment. The entire system uses one set of air-cooled heat exchangers and one set of water-cooled heat exchangers. Compared with the existing technology, this greatly reduces the number of system devices, reduces the overall resource occupation, and reduces the occupied space.

[0017] 2) The present invention adopts a cooling solution that combines air cooling and water cooling in series, which can meet the needs of high-load heat extraction in the early stage of an accident, and rely on air cooling to achieve low-load heat extraction in the later stage of the accident. Compared with the existing technology, it reduces the system's demand for cooling water volume and increases the system's effective heat removal operating time.

[0018] 3) The present invention is designed with an automatic air exhaust valve, which can timely exhaust the air in the heat exchanger when the system is running, effectively improving the cooling and heat exhaust power of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1It is a structural diagram of a specific embodiment of the present invention.

[0020] Among them, 1: containment, 2: reactor pressure vessel, 3: steam generator; 4: air-cooling tower, 5: air-cooled heat exchanger, 6: cooling water tank, 7: water-cooled heat exchanger, 8: first cooling isolation valve, 9: first automatic air exhaust valve, 10: first residual exhaust solenoid valve, 11: check valve, 12: water injection isolation valve, 13: gas collecting tank, 14: automatic exhaust valve, 15: filter discharge device, 16: discharge isolation valve, 17: second cooling isolation valve, 18, second residual exhaust isolation valve, 19, second automatic air exhaust valve, 20, third automatic air exhaust valve. DETAILED DESCRIPTION

[0021] To make the objectives, technical solutions, and advantages of this application more clear, the technical solutions of this application will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0022] In the description of the embodiments of the present application, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the embodiments of the present application. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0023] In the description of the embodiments of this application, it should be noted that, unless otherwise specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of this application based on the specific circumstances.

[0024] In the embodiments of the present application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, a first feature being "above," "above," and "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0025] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiments of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples, unless they are contradictory. In addition, the term "plurality" means including two or more.

[0026] like Figure 1 The passive core and containment cooling and heat removal system shown is specifically a combined air-cooling and water-cooling passive core and containment cooling and heat removal system, including a steam generator 3, an air-cooled heat exchanger 5, an exhaust unit and a water-cooled heat exchanger 7; The steam generator 3 is arranged in the containment vessel 1, and the primary side of the steam generator 3 is connected to the interior of the pressure vessel 2 of the reactor through a pipeline; the secondary side outlet of the steam generator 3 is connected to the heat source channel inlet of the air-cooled heat exchanger 5 outside the containment vessel 1 through a first pipeline, and a first waste heat discharge solenoid valve 10 (specifically, a first waste heat discharge solenoid valve) is provided on the first pipeline, and the first pipeline is connected to the steam main pipe; the heat source channel outlet of the air-cooled heat exchanger 5 is connected to the heat source channel inlet of the water-cooled heat exchanger 7; the heat source channel of the air-cooled heat exchanger 5 is connected to the exhaust unit inlet through a pipeline, and the outlet of the exhaust unit is connected to the atmosphere; the heat source channel outlet of the water-cooled heat exchanger 7 is connected to the secondary side inlet of the steam generator 3 through a second pipeline, and a second waste heat discharge solenoid valve 18 and a check valve 11 are provided on the second pipeline, and the second pipeline is connected to the water supply main pipe; The interior of the containment shell 1 is connected to the first pipeline through a third pipeline, and a first cooling isolation valve 8 is arranged on the third pipeline; the interior of the containment shell 1 is connected to the second pipeline through a fourth pipeline, and a second cooling isolation valve 17 is arranged on the fourth pipeline.

[0027] In the present invention, two groups of steam generators 3 are arranged in the containment vessel 1. The primary side of the steam generator 3 forms a core primary circuit with the reactor pressure vessel 2, the main pump, etc. through pipelines. The core primary circuit and the secondary circuit realize heat transfer through the steam generator 3. The high-temperature coolant in the primary circuit transfers heat to the secondary circuit in the steam generator 3. This is a well-known technology in the industry and will not be repeated here.

[0028] Preferably, the air-cooled heat exchanger 5 is arranged in the air-cooling tower 4 and tilted downward at a certain angle in the horizontal direction (the outlet end of the heat source channel of the air-cooled heat exchanger is lower than the height of the inlet end of the heat source channel) to facilitate the discharge of condensate and the collection of non-condensable gas; the water-cooled heat exchanger 7 is arranged in the cooling water tank 6.

[0029] In the present invention, the air-cooling heat exchanger 5 and the water-cooling heat exchanger 7 are both arranged outside the containment vessel 1 , and the air-cooling tower 4 is arranged above the cooling water tank 6 .

[0030] Preferably, the fourth pipeline is communicated with the fifth pipeline, and the fifth pipeline penetrates into the interior of the containment vessel 1 and is communicated with the interior of the core.

[0031] In the present invention, the fifth pipeline is provided with a core water injection isolation valve 12; under severe accident conditions, the condensate at the outlet of the water-cooled heat exchanger 7 flows into the core through the fifth pipeline by gravity to achieve core cooling.

[0032] Preferably, the exhaust unit includes an air collecting tank 13, a filtering and exhausting device 15 and an exhaust pipeline; the air collecting tank 13 is connected to the heat source channel of the air-cooled heat exchanger 5 through the sixth pipeline, and the sixth pipeline is provided with a first automatic air exhaust valve 9; the outlet of the air collecting tank 13 is connected to the inlet of the filtering and exhausting device 15 through the seventh pipeline, and the outlet of the filtering and exhausting device 15 is connected to the outside atmosphere through the exhaust pipeline.

[0033] In the present invention, the seventh pipeline is provided with an automatic exhaust valve 14 ; the exhaust pipeline is provided with a discharge isolation valve 16 .

[0034] Preferably, the heat source channel inlet of the water-cooled heat exchanger 7 is provided with a first bypass line connected to the sixth line, and a second automatic air exhaust valve 19 is configured on the first bypass line; the heat source channel outlet of the water-cooled heat exchanger 7 is provided with a second bypass line connected to the sixth line, and a third automatic air exhaust valve 20 is configured on the second bypass line. In the present invention, the second and third bypass lines are designed to exhaust air and water vapor from the heat source channels of the water-cooled heat exchanger and the air-cooled heat exchanger.

[0035] In the present invention, the gas collecting tank 13 collects the air and a small amount of steam discharged from the air-cooled heat exchanger 5 and the water-cooled heat exchanger 7 through the corresponding automatic air exhaust valves. The design pressure of the gas collecting tank 13 is slightly higher than the pressure of the containment shell 1 after the accident and can be designed at 1 MPa; the gas collecting tank 13 is connected to the filtering and exhausting device 15. When the pressure of the gas collecting tank 13 is close to the design pressure of the system pipeline, the automatic exhaust valve 14 between the gas collecting tank 13 and the filtering and exhausting device 15 automatically opens based on the pressure difference, and the radioactive substances in the gas are filtered and discharged.

[0036] In the present invention, each isolation valve is remotely opened and closed when powered on, and manually opened and closed on site when powered off; each solenoid valve is set to be normally closed when powered on and normally open when powered off.

[0037] Under normal operating conditions, the first cooling isolation valve 8 and the second cooling isolation valve 17 are closed to isolate the containment vessel 1; the first residual row solenoid valve 10 and the second residual row solenoid valve 18 are in the energized closed state to isolate the secondary side of the steam generator 3; other valves in the system are also in the closed state.

[0038] When a LOCA accident occurs in the containment vessel 1, the passive core and containment cooling and heat removal system of the present invention is used. Driven by the pressure difference, the high-temperature and high-pressure steam in the containment vessel 1 enters the air-cooled heat exchanger 5 and the water-cooled heat exchanger 7 for condensation. The condensate flows into the containment vessel 1 under the action of gravity, thereby reducing the temperature and pressure of the containment vessel 1. Specifically, a method for cooling the containment vessel 1 based on the passive core and containment cooling and heat removal system is as follows: When a LOCA accident occurs in the containment vessel 1, the first cooling isolation valve 8 and the second cooling isolation valve 17 are opened remotely or locally, and the system is put into operation as a passive containment cooling system. The high-temperature and high-pressure steam in the containment vessel 1 enters the air-cooling heat exchanger 5 located in the air-cooling tower 4, exchanges heat with the atmosphere outside the air-cooling heat exchanger 5, and then enters the water-cooling heat exchanger 7 located in the cooling water tank 6 to exchange heat with the cooling water, thereby extracting heat from the containment vessel 11. During the operation of the system, when gas is generated in the air-cooled heat exchanger 5 and the water-cooled heat exchanger 7, the automatic air exhaust valve on the corresponding pipeline will automatically open when it detects air, and discharge the air into the gas collecting tank 13; after the air is discharged, the corresponding automatic air exhaust valve will automatically close; as the air in the system pipeline is intermittently discharged, the air in the gas collecting tank 13 gradually accumulates and the pressure gradually increases; when the pressure of the gas collecting tank 13 rises to the set pressure, the automatic exhaust valve 14 between the gas collecting tank 13 and the filter discharge device 15 is opened, and the discharge isolation valve 16 is opened remotely or manually on site to filter the air in the gas collecting tank 13 and discharge it.

[0039] When a plant-wide power outage or reactor shutdown occurs, the passive core and containment cooling and heat removal system of the present invention is required to remove heat from the core. Specifically, a method for removing heat from the core based on the passive core and containment cooling and heat removal system is as follows: When a plant-wide power outage occurs and the reactor is shut down, the first and second residual heat removal solenoid valves 10 and 18 are de-energized and automatically opened, and the system is put into operation as a passive residual heat removal system; the core heat is transferred to the secondary side of the steam generator 3 through a natural circulation of the primary loop; the steam on the secondary side of the steam generator 3 enters the air-cooled heat exchanger 5 located in the air-cooling tower 4 due to the natural circulation caused by the density difference, and after exchanging heat with the atmosphere outside the air-cooled heat exchanger 5, enters the water-cooled heat exchanger 7 located in the cooling water tank 6 to exchange heat with the cooling water, thereby bringing the primary loop heat to the atmosphere and the cooling water tank 6, thereby achieving cooling and pressure reduction of the primary loop.

[0040] Under severe accident conditions, such as a core meltdown, the core water injection isolation valve 12 is opened electrically remotely or manually on-site, and the condensate at the outlet of the water-cooled heat exchanger 7 in the passive core and containment cooling and heat removal system flows into the core by gravity, thereby achieving core cooling.

[0041] In the present invention, when a plant-wide power outage or reactor shutdown occurs, or when a LOCA accident occurs within containment vessel 1, high-temperature, high-pressure steam within containment vessel 1, driven by a pressure differential, enters the air-cooled heat exchanger 5 and the water-cooled heat exchanger 7 for condensation. The condensate then flows into containment vessel 1 under the action of gravity, thereby reducing the temperature and pressure of containment vessel 1. When a plant-wide power outage or reactor shutdown occurs, core heat is transferred to the secondary side of steam generator 3 through natural circulation in the primary circuit. The secondary side steam, due to natural circulation caused by density differences, enters the air-cooled heat exchanger 5 and the water-cooled heat exchanger 7 for condensation and heat exchange, thereby transferring the primary circuit heat to the atmosphere and cooling water tank 6, thereby reducing the temperature and pressure of the primary circuit.

[0042] The present invention adopts an in-tube condensation scheme with air cooling and water cooling in series (an air-cooled heat exchanger 5 and a water-cooled heat exchanger 7 are arranged outside the containment vessel 1), air cooling is performed first and then water cooling, and the core heat removal and the containment vessel 1 cooling are integrated into a design. By switching valves, the entire system can be used as a passive residual heat removal system to remove heat from the reactor core, and can also be used as a passive containment vessel cooling system to cool the containment vessel 1; the entire system shares a set of air-cooling towers 4, a set of air-cooling heat exchangers 5, a set of cooling water tanks 6, and a set of water-cooling heat exchangers 7.

[0043] The present invention provides automatic air exhaust valves based on the principle of thermostatics at the top of the air-cooled heat exchanger 5 and the water-cooled heat exchanger 7 and in corresponding dead zones of air flow; a short pipe of no less than 300 mm is installed in front of the automatic air exhaust valve to accumulate air and at the same time make the temperature of the automatic air exhaust valve lower than the mainstream temperature of the steam pipe to ensure the normal operation of the automatic air exhaust valve.

[0044] The contents not described in detail in this specification belong to the prior art known to those skilled in the art.

[0045] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent replacements for some of the technical features therein. However, any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A passive core and containment cooling and heat removal system, characterized in that: It includes steam generator, air-cooled heat exchanger, exhaust unit and water-cooled heat exchanger; The steam generator is arranged in the containment vessel, and the primary side of the steam generator is connected to the interior of the pressure vessel of the reactor through a pipeline; the secondary side outlet of the steam generator is connected to the inlet of the heat source channel of the air-cooled heat exchanger outside the containment vessel through a first pipeline, a first excess solenoid valve is provided on the first pipeline, and the first pipeline is connected to the steam main pipe; the heat source channel outlet of the air-cooled heat exchanger is connected to the heat source channel inlet of the water-cooled heat exchanger; the heat source channel of the air-cooled heat exchanger is connected to the inlet of the exhaust unit through a pipeline, and the outlet of the exhaust unit is connected to the atmosphere; the heat source channel outlet of the water-cooled heat exchanger is connected to the secondary side inlet of the steam generator through a second pipeline, a second excess solenoid valve and a check valve are provided on the second pipeline, and the second pipeline is connected to the water supply main pipe; The interior of the containment shell is connected to the first pipeline through a third pipeline, and a first cooling isolation valve is arranged on the third pipeline; the interior of the containment shell is connected to the second pipeline through a fourth pipeline, and a second cooling isolation valve is arranged on the fourth pipeline.

2. The passive core and containment cooling and heat removal system according to claim 1, wherein: The air-cooling heat exchanger is arranged in an air-cooling tower; the water-cooling heat exchanger is arranged in a cooling water tank.

3. The passive core and containment cooling and heat removal system according to claim 2, wherein: The air-cooled heat exchanger and the water-cooled heat exchanger are both arranged outside the containment vessel.

4. The passive core and containment cooling and heat removal system according to claim 3, wherein: The fourth pipeline is communicated with the fifth pipeline, and the fifth pipeline penetrates into the interior of the containment vessel and is communicated with the interior of the core.

5. The passive core and containment cooling and heat removal system according to claim 4, characterized in that: The fifth pipeline is provided with a core water injection isolation valve.

6. The passive core and containment cooling and heat removal system according to claim 5, characterized in that: The exhaust unit includes an air collecting tank, a filtering and exhausting device, and an exhaust pipeline; the air collecting tank is connected to the heat source channel of the air-cooled heat exchanger through a sixth pipeline, and a first automatic air exhaust valve is arranged on the sixth pipeline; the outlet of the air collecting tank is connected to the inlet of the filtering and exhausting device through a seventh pipeline, and the outlet of the filtering and exhausting device is connected to the outside atmosphere through the exhaust pipeline.

7. The passive core and containment cooling and heat removal system according to claim 6, wherein: The seventh pipeline is provided with an automatic exhaust valve; the exhaust pipeline is provided with a discharge isolation valve.

8. The passive core and containment cooling and heat removal system according to claim 6 or 7, characterized in that: The inlet of the heat source channel of the water-cooled heat exchanger is provided with a first bypass pipeline connected to the sixth pipeline, and a second automatic air exhaust valve is arranged on the first bypass pipeline; the outlet of the heat source channel of the water-cooled heat exchanger is provided with a second bypass pipeline connected to the sixth pipeline, and a third automatic air exhaust valve is arranged on the second bypass pipeline.

9. A method for cooling a containment vessel based on the passive core and containment vessel cooling and heat removal system according to claim 7, characterized in that: The method is: When a LOCA accident occurs in the containment, the first cooling isolation valve and the second cooling isolation valve are opened remotely or locally, and the steam in the containment enters the air-cooled heat exchanger, exchanges heat with the atmosphere outside the air-cooled heat exchanger, and then enters the water-cooled heat exchanger to exchange heat with the cooling water, thereby extracting the heat from the containment. During system operation, when gas is generated in the air-cooled heat exchanger and the water-cooled heat exchanger, the automatic air exhaust valve on the corresponding pipeline will automatically open when it detects air, and discharge the air into the gas collecting tank; when the pressure in the gas collecting tank rises to the set pressure, the automatic exhaust valve between the gas collecting tank and the filter discharge device will open, and the discharge isolation valve will be opened at the same time to filter the air in the gas collecting tank and discharge it.

10. A method for removing heat from a reactor core based on the passive core and containment cooling and heat removal system according to claim 7, characterized in that: The method is: When a power outage occurs in the entire plant and the reactor is shut down, the first and second residual solenoid valves are de-energized and automatically open, and the core heat is transferred to the secondary side of the steam generator through the primary natural circulation; the steam on the secondary side of the steam generator enters the air-cooled heat exchanger due to the natural circulation caused by the density difference, exchanges heat with the atmosphere outside the air-cooled heat exchanger, and then enters the water-cooled heat exchanger to exchange heat with the cooling water, bringing the primary circuit heat to the atmosphere and the cooling water tank, thereby achieving cooling and pressure reduction of the primary circuit.

Images