MAIN HEAT SINK SYSTEM FOR ACTIVE AND PASSIVE COOPERATIVE COOLING OF A NUCLEAR POWER STATION

Abstract

A method for the active and passive cooperative cooling of a nuclear power station and a primary heat sink system for use with said method are presented. The method includes: the conduction, in the event of a design-base failure and when a primary circuit pressure boundary is intact, of thermal energy in a containment to a heat sink through an active secondary circuit purge and feed system; and the automatic commissioning, in the event of a beyond-design-base failure of the station and when the primary circuit pressure boundary is intact, of a passive secondary circuit natural circulation system, such that the heat transferred from the containment to the active secondary circuit purge and feed system is conducted into the heat sink.Furthermore, the natural circulatory system of the passive secondary circuit is presented, which can be automatically activated in the event of an accident beyond the station's design blackout threshold and when the pressure limit of the primary circuit is intact, so that the heat transferred from the containment to the purge and feed system of the active secondary circuit can be conducted into the heat sink, thus carrying out active and passive cooperative cooling, accelerating the heat dissipation process in the containment that is being conducted in the event of an accident, and improving the safety of the nuclear power plant.

Description

METHOD FOR THE ACTIVE AND PASSIVE COOPERATIVE COOLING OF A NUCLEAR POWER STATION, AND MAIN HEAT SINK SYSTEM FOR USE WITH SAID METHOD Technical field The present invention pertains to the field of nuclear power plant system design, and specifically relates to a main heat sink system for the active and passive cooperative cooling of a nuclear power station. Background Since the Fukushima nuclear accident, the safety and diversity of countermeasures at nuclear power plants have garnered widespread attention. In recent years, new processes in international nuclear power plant construction emphasize the adoption of third-generation nuclear power units, which are safer and more advanced. Nuclear power plants designed in the United States employ a comprehensive passive safety system to address both design-based and beyond-design accidents, and the primary heat sink dissipates heat into the air through a containment air cooling system. 1721514 of 45 On the contrary, nuclear power plants in France employ multiple sets of active safety systems to address accidents, and the main heat sink transfers heat to the seawater through active system circulation. These main heat sinks in nuclear power plants are relatively simple and can lead to serious consequences in the event of common-cause failures. For other power plants with various main heat sink systems currently in use, most of the heat sink systems operate independently, without any collaboration or mutual support. Summary An object of the invention is to present a main heat sink system for the active and passive cooperative cooling of a nuclear power station, which can accelerate the process of heating the containment being carried out in the event of an accident, and improve the safety of the nuclear power plant. The technical solutions for carrying out the present invention are as follows: A method for the active and passive cooperative cooling of a station 1721514 of 45 nuclear energy that includes: The conduction, in the event of a basic design accident and when the pressure limit of a primary circuit is intact, of thermal energy in a containment towards a heat sink through a purging and active secondary circuit feeding system, and the automatic start-up, in the event of an accident beyond the basic design of station darkening and when the pressure limit of the primary circuit is intact, of a natural circulatory system of passive secondary circuit, so that the heat transferred from the containment to the purging and feeding system of the active secondary circuit is directed towards the interior of the heat sink. Preferably, in the event of a base design accident and when the primary circuit is damaged, the thermal energy in the containment is conducted to the heat sink through an active containment cooling system, and in the event of an accident beyond the base design of station blackout and when the primary circuit is too damaged to establish natural circulation, a passive thermal containment pipe cooling system is automatically started, so that the heat transferred from the containment to the active containment cooling system 1721514 of 45 is directed towards the heat sink. Preferably, in the event of a design-based accident and when the primary circuit is damaged, through the active containment cooling system, the thermal energy in the containment is conducted to the heat sink via an armor water cooling system. A primary heat sink system for the active and passive cooperative cooling of a nuclear power station includes a control module, an active secondary circuit purging and feeding system, and a passive secondary circuit natural circulatory system. The active secondary circuit purging and feeding system is connected to the containment, and the control module is electrically connected to the active secondary circuit purging and feeding system and configured to control, in the event of a design basis accident and when the pressure limit of a primary circuit is intact, to start the active secondary circuit purging and feeding system, so that the thermal energy in the containment is conducted to a heat sink. The natural circulatory system of the passive secondary circuit is connected to both the containment and the purge and feed system of the active secondary circuit and is configured to start automatically in the event of an accident beyond the station's base darkening design and 1721514 of 45 when the primary circuit pressure limit is intact, so that the heat transferred from the containment to the active secondary circuit's purge and feed system is conducted into the heat sink. Preferably, the active secondary circuit purge and feed system includes an emergency water supply tank and an evaporator, wherein the emergency water supply tank is disposed outside the containment, the evaporator is located inside the containment, the emergency water supply tank is in communication with the evaporator through a first pipe in which an emergency water supply pump is disposed, and the emergency water supply pump is configured to pump emergency water in the emergency water supply tank into the evaporator, a steam pipe penetrating the containment is connected to the evaporator, the emergency water entering the evaporator exchanges heat with hot air entering the evaporator from the containment, and then after evaporation, is guided out of the containment through the steam pipe; The passive secondary circuit's natural circulatory system includes an external water tank and a secondary circuit natural circulation heat exchanger, where the external water tank is arranged on an external side wall of the containment, and the secondary circuit natural circulation heat exchanger is 1721514 of 45 located inside the water tank outside the containment and is disposed above the evaporator, the secondary circuit natural circulation heat exchanger and the evaporator are connected in a circulation circuit through a second pipe on which a first pneumatic fusible valve is presented in the containment, and the first pneumatic fusible valve is configured to open automatically when the temperature in the containment exceeds a first set value, a first cooling medium in the secondary circuit natural circulation heat exchanger enters the evaporator by gravity action, returns to the secondary circuit natural circulation heat exchanger after being vaporized at high temperature in the containment, and exchanges heat by cooling water in the water tank outside the containment to form a first liquid cooling medium. Preferably, the system also includes an active containment cooling system and a passive containment thermal pipe cooling system. The active containment cooling system is connected to the containment. The control module is also electrically connected to the active containment cooling system and is configured to control, in the event of a design basis accident and when the primary circuit is damaged, the activation of the active containment cooling system. 1721514 of 45 so that the thermal energy in the containment is conducted to the heat sink, and the passive containment thermal pipe cooling system is connected to the containment and corresponds to the active containment cooling system, and is configured to automatically start up in the event of an accident beyond the station's base darkening design and when the primary circuit is too damaged to establish natural circulation, so that the heat transferred from the containment to the active containment cooling system is directed into the heat sink. Preferably, the active containment cooling system includes a water tank inside the containment and a vaporization mechanism, wherein the water tank inside the containment is disposed inside and at a lower portion of the containment, the vaporization mechanism is located inside and above a higher portion of the containment, the water tank inside the containment and the vaporization mechanism are sequentially connected via a third pipe on which a containment coolant pump is located, and the containment coolant pump is configured to pump coolant water into the water tank inside the containment into the vaporization mechanism, where the vaporization mechanism atomizes and vaporizes the coolant water 1721514 of 45 to cool the team in containment; The passive containment thermal pipe cooling system includes an upper thermal pipe cooling system including a containment thermal pipe heat exchanger inside the containment and a containment thermal pipe heat exchanger outside the containment. The containment thermal pipe heat exchanger outside the containment is arranged in the water tank outside the containment. The containment thermal pipe heat exchanger inside the containment is located inside the containment and arranged below the containment thermal pipe heat exchanger outside the containment.The upper thermal pipe cooling system includes a circulation circuit formed by the containment thermal pipe heat exchanger inside the containment and the containment thermal pipe heat exchanger outside the containment via a fourth pipe on which a second pneumatic fusible valve is presented in the containment, and the second pneumatic fusible valve is configured to open automatically when the temperature in the containment exceeds a second set value, a second cooling medium in the containment thermal pipe heat exchanger outside the containment enters the containment thermal pipe heat exchanger inside the, 1721514 of 45 gravity containment, returns to the heat exchanger of the containment thermal pipe outside the containment after being vaporized at high temperature in the containment, and exchanges heat for cooling water in the water tank outside the containment to form a second liquid cooling medium, in which the second set value is greater than the first set value. Preferably, the vaporization structure includes a first vaporizer and a second vaporizer, where the first vaporizer is located in the upper center of the containment and has a vaporization range compatible with the main heat generation equipment in the containment, and the second vaporizer is located above the containment thermal pipe heat exchanger within the containment and has a vaporization range compatible with the containment thermal pipe heat exchanger within the containment. Preferably, the passive containment thermal pipe cooling system further includes a lower thermal pipe cooling system comprising a water tank thermal pipe heat exchanger inside the containment and an air thermal pipe heat exchanger outside the containment, wherein the water tank thermal pipe heat exchanger inside the containment is arranged in the water tank inside the containment, the pipe heat exchanger 1721514 of 45 air thermal outside the containment is located outside the containment and arranged over the water tank thermal pipe heat exchanger inside the containment, and the water tank thermal pipe heat exchanger inside the containment and the air thermal pipe heat exchanger outside the containment form a circulation circuit through a fifth pipe, a third cooling medium in the air thermal pipe heat exchanger outside the containment enters the water tank thermal pipe heat exchanger inside the containment by gravity action, returns to the air thermal pipe heat exchanger outside the containment after being vaporized at high temperature in the containment, and exchanges heat by air outside the containment to form a third liquid cooling medium. Preferably, the active containment cooling system further includes a high-pressure water supply tank connected to a third pipe via a sixth pipe and located between the containment cooling pump and the vaporization structure; a check valve is provided on the sixth pipe, a lower portion of the high-pressure water supply tank is filled with cooling water, while an upper portion of the high-pressure water supply tank is filled with high-pressure gas, and when the check valve is opened, the water from 1721514 of 45 refrigeration at the bottom is pressed inside the vaporization structure by means of high pressure gas in the high pressure water supply tank. Preferably, the active containment cooling system also includes a containment heat exchanger located above the third pipe and outside the containment; the main heat sink system also includes an active shield cooling system connected to the containment heat exchanger and configured so that the heat transferred from the containment to the containment heat exchanger is directed into the heat sink. Preferably, the active shielding cooling water system includes a heat sink heat exchanger and a cooling tower, wherein the heat sink heat exchanger and the containment heat exchanger form a circulation loop through piping, wherein the circulation loop is configured to introduce a cooling medium into the containment heat exchanger to cool the cooling water in the containment heat exchanger, and then the cooling medium returns to the heat sink heat exchanger, and 1721514 of 45 The cooling tower and the heat sink heat exchanger form a circulation circuit through pipes. The circulation circuit is configured to introduce ambient water into the heat sink heat exchanger to cool the cooling medium in the heat sink heat exchanger. The heated ambient water enters the cooling tower and exchanges heat with air, and then the cooled ambient water returns to the heat sink heat exchanger. Preferably, the first pneumatic fusible valve and the second pneumatic fusible valve each include a main valve, a pneumatic actuator, and a fusible valve, wherein the main valve has a valve cavity in which the valve seat is presented, and the valve seat divides the valve cavity into a liquid inlet cavity and a liquid outlet cavity, and a valve port communicating the liquid inlet cavity with the liquid outlet cavity disposed on the valve seat, one end of the pneumatic actuator is connected to a gas supply source in a power plant through a fusible valve, while the other end of the pneumatic actuator penetrates the main valve to connect, in a sliding manner, to the main valve and has a valve core at one end and mates with the valve port of the valve seat, and 1721514 of 45 The fusible valve opens after the temperature in the containment exceeds a set value so that the pneumatic actuator moves towards the valve port by the pressure of the gas transmitted from the gas supply source, until the valve core closes the valve port. Preferably, the fusible valve includes a valve body, a valve stem, a spring, and a fusible link. The valve body has a reservoir, a gas inlet, a gas outlet, and an exhaust port. The gas inlet is connected to the gas supply source in the power plant, the gas outlet is connected to the pneumatic actuator, and the exhaust port is open to the atmosphere. The reservoir is axially arranged along the valve stem, and the gas inlet, gas outlet, and exhaust ports are axially arranged along the valve stem at intervals, each communicating with the reservoir. A lower portion of the valve stem extends into the reservoir.and is provided with a valve ball connected to a wall of the container bore in a sealed and sliding manner, the spring is in a compressed condition and encased over an upper portion of the valve stem, and the fusible link is fixed to both ends of the spring in the axial direction so that the spring remains compressed, and, 1721514 of 45 The valve stem has a normal state and a high temperature condition. When the valve stem is in a normal condition, the valve ball is located between the gas outlet port and the exhaust port so that the gas inlet port and the gas outlet port are connected while the gas outlet port and the exhaust port are disconnected. When the valve stem is in a high temperature condition, the fusible link melts at high temperature in the containment so that the spring extends to push the valve stem to move axially, until the valve ball is located between the gas inlet port and the gas outlet port so that the gas inlet port and the gas outlet port are disconnected while the gas outlet port and the exhaust port are connected. Preferably, the water tank outside the containment is provided with a water baffle to divide the water tank outside the containment into a first cooling compartment for cooling the naturally circulating heat exchanger of the secondary circuit and a second cooling compartment for cooling the heat exchanger of the thermal piping of the containment outside the containment, and when the water pressure on either side of the water baffle is greater than the set value, the cooling water on the higher pressure side can push the water baffle open to connect the first cooling compartment with the second 1721514 of 45 refrigerant compartment. Preferably, the water deflector includes a door frame and at least one door leaf structure. An external side surface of the door frame is connected to the water tank outside the containment in a sealed manner. The door leaf structure includes a linkage mechanism and two leaves. The ends of the two leaves closest to each other are hinged to the door frame, and a sealing ring is arranged on an external side surface of each leaf. The linkage mechanism includes two connecting rods and a constant-force spring. The two connecting rods correspond to the two leaves one by one; the ends of the two connecting rods furthest from each other are hinged to the corresponding leaves, and the ends of the two connecting rods closest to each other are connected to the two ends of the constant-force spring.When the water pressure on either side of the water deflector is greater than the spring force of the constant force spring, the cooling water on a higher pressure side can push each leaf to rotate around a hinge point so that, by means of the sealing ring in a sealed position, the leaf and door frame are connected and adjacent leaves are connected, or the leaf and door frame are disconnected from each other and adjacent leaves are disconnected from each other. 1721514 of 45 In the present invention, by additionally providing the natural secondary circuit circulatory system connected to both the containment and the active secondary circuit purge and feed system, the passive secondary circuit natural circulatory system can be automatically activated when the temperature in the containment exceeds a set value, especially in the event of an accident beyond the base design blackout of the station and when the pressure limit of the primary circuit is intact, so that the heat transferred from the containment to the active secondary circuit purge and feed system is directed into the heat sink, thereby carrying out active and passive cooperative cooling, accelerating the heat dissipation process in the containment that is being driven towards an accident, and improving the safety of the nuclear power plant. Brief description of the figures Figure 1 is a general assembly diagram of a main heat sink system for the active and passive cooperative cooling of a nuclear power station presented in a first embodiment of the present invention; Figure 2 is a schematic diagram of a pneumatic fusible valve; Figure 3 is a schematic diagram showing an internal interface of 1721514 of 45 the fusible valve; Figure 4 is a front view of a water deflector; Figure 5 is a top view of the closed water deflector; and Figure 6 is a top view of the open water deflector. In the figures: 1 - active secondary circuit purge and feed system; 2 - active containment cooling system; 3 - active shielding cooling water system; 4 - passive secondary circuit natural circulation system; 5 - passive containment thermal pipe cooling system; 7 - containment; 8 - upper thermal pipe cooling system; 9 - lower thermal pipe cooling system; 10 - emergency water supply tank; 11 - emergency water supply pump; 12 - evaporator; 13 - relief valve; 20 - water tank inside the containment; 21 - containment cooling pump; 22 - containment heat exchanger; 23 - first evaporator; 24 - second evaporator; 25 - high-pressure water supply tank; 31 - shielding water pump; 32 - heat sink heat exchanger; 33 - heat sink pump; 40 - valve stem;41 - first pneumatic fusible valve; 42 - secondary circuit natural circulation heat exchanger; 43 - water tank outside the containment; 44 - fusible link; 45 - spring; 46 - water deflector; 47 - main valve; 48 - actuator; 1721514 of 45 pneumatic; 481 - valve core; 49 - fusible valve; 410 - valve stem; 411 - valve ball; 50 - containment thermal pipe heat exchanger inside the containment; 51 - second pneumatic fusible valve; 52 - containment thermal pipe heat exchanger outside the containment; 53 - water tank thermal pipe heat exchanger inside the containment; 54 - water tank isolation valve outside the containment; 55 - air thermal pipe heat exchanger outside the containment; 461 - blade; 462 - coupling rod; 463 - constant force spring; 464 - sealing ring and 465 - door frame. Detailed description of the achievements For a better understanding of the technical solution of the present invention for those skilled in the prior art, this invention shall now be described in detail together with the accompanying figures and embodiments. The embodiments of the present invention shall be described in detail with examples thereof shown in the figures of the invention, in which the same or similar symbols refer to the same or similar elements or to elements with the same or similar functions. The embodiments described below, which refer to the figures, are 1721514 of 45 are merely illustrative, and are used solely for the explanatory purposes of the present invention and should not be interpreted as limitations of the present invention. First realization With reference to Figure 1, this embodiment presents a method for the active and passive cooperative cooling of a nuclear power station, including: The conduction, in the event of a basic design accident and when a primary circuit pressure limit is intact, of thermal energy in a containment 7 towards a heat sink through an active secondary circuit purge and feed system 1, and the automatic start-up, in the event of an accident beyond the basic design of station blackout and when the primary circuit pressure limit is intact, of a natural circulatory system of secondary circuit 4, so that the heat transferred from containment 7 to the active secondary circuit purge and feed system 1 is conducted into the heat sink. Specifically, in the present embodiment, in the event of a design failure and when the primary circuit is damaged, through the system of 1721514 of 45 active containment cooling 2, thermal energy in containment 7 is conducted to the heat sink through a shield cooling water system 3. In the present embodiment, in the event of a base design accident and when the primary circuit is damaged, the thermal energy in containment 7 is directed to the heat sink through an active containment cooling system 2, and in the event of an accident beyond the base design of station blackout and when the primary circuit is too damaged to establish natural circulation, a thermal pipe cooling system of passive containment 5 is automatically started, so that the heat transferred from containment 7 to the active containment cooling system 2 is directed into the heat sink. Second realization As shown in Figure 1, the present embodiment presents a main heat sink system for the active and passive cooperative cooling of a nuclear power station, including a control module, an active secondary circuit purge and feed system 1, an active containment cooling system 2, and a shielding coolant water system. 1721514 of 45 active 3, a passive secondary circuit natural circulatory system 4 and a passive containment thermal pipe cooling system 5. The active secondary circuit 1 purge and feed system penetrates containment 7 to connect, in a fixed manner, below the passive secondary circuit 4 natural circulatory system, and the active secondary circuit 1 purge and feed system is connected to the passive secondary circuit 4 natural circulatory system via piping. The active containment 2 cooling system penetrates containment 7 to connect, in a fixed manner, above the active armor 3 cooling water system. The active armor 3 cooling water system is connected to the active containment 2 cooling system via a containment heat exchanger 22, and the active armor 3 cooling water system is located outside containment 7. The passive containment thermal pipe cooling system 5 includes an upper thermal pipe cooling system 8 and a lower thermal pipe cooling system 9 which are arranged, respectively, at an upper and lower part of the containment 7. The passive secondary circuit natural circulatory system 4 and the passive containment thermal piping cooling system 5 share a common water tank outside of containment 43. 1721514 of 45 The purging and feeding system of active secondary circuit 1 is connected to containment 7, and the control module is electrically connected to the purging and feeding system of active secondary circuit 1 and configured to control, in the event of a design basis accident and when the pressure limit of a primary circuit is intact, the start-up of the purging and feeding system of active secondary circuit 1, so that the thermal energy in containment 7 is conducted to a heat sink. The natural circulatory system of the passive secondary circuit 4 is connected to both containment 7 and the purge and feed system of the active secondary circuit 1 and is configured to start automatically in the event of an accident beyond the station's base darkening design and when the pressure limit of the primary circuit is intact (in this case, a temperature in containment 7 exceeding a first set value), so that the heat transferred from containment 7 to the purge and feed system of the active secondary circuit 1 is conducted into the heat sink. By additionally having the passive secondary circuit natural circulatory system 4 connected to both containment 7 and the active secondary circuit purge and feed system 1, the passive secondary circuit natural circulatory system 4 can be automatically activated when the temperature in containment 7 exceeds a set value, especially in the event of a 1721514 of 45 accident beyond the station's basic darkening design and when the primary circuit pressure limit is intact, so that the heat transferred from containment 7 to the active secondary circuit 1 purge and feed system can be conducted into the heat sink, thereby carrying out active and passive cooperative cooling, accelerating the heat process in the containment being conducted in the event of an accident, and improving the safety of the nuclear power plant. The active containment cooling system 2 is connected to containment 7, and the control module is also electrically connected to the active containment cooling system 2 and is configured to control, in the event of a design basis accident and when the primary circuit is damaged, the start-up of the active containment cooling system 2, so that the thermal energy in containment 7 is conducted to the heat sink. The containment 22 heat exchanger is arranged outside of containment 7 and the active shielding 3 cooling water system is connected to the containment 22 heat exchanger and is configured so that the heat transferred from containment 7 to the containment 22 heat exchanger is conducted into the heat sink. By additionally providing the active shield cooling water system 3 connected to the active containment cooling system 2, the system of 1721514 of 45 active containment cooling 2 can be aided so that in the event of a design basis accident and when the primary circuit is damaged, the heat transferred from containment 7 to the active containment cooling system 2 is conducted into the heat sink, thus also carrying out active and passive cooperative cooling, accelerating the heat process in the containment that is leading to an accident and improving the safety of the nuclear power plant. The passive containment 5 thermal pipe cooling system is connected to containment 7 and corresponds to the active containment 2 cooling system. It is configured to automatically activate in the event of an accident exceeding the station's base blackout design and when the primary circuit pressure limit is too compromised to establish natural circulation (in this case, a temperature in containment 7 exceeding a second preset value). This activation allows the heat transferred from containment 7 to the active containment 2 cooling system to be conducted into the heat sink. The second preset value is higher than the first preset value. By additionally providing the cooling system for the passive containment heat pipe 5 corresponding to the active containment heat pipe cooling system 2, the cooling system for the passive containment heat pipe 5 can be started automatically when the 1721514 of 45 temperature in containment 7 exceeds a set value, especially in the event of an accident beyond the station's basic darkening design and when the primary circuit is damaged, so that the heat transferred from containment 7 to the active containment cooling system 2 is conducted into the heat sink, also carrying out, in this way, active and passive cooperative cooling, accelerating the heat process in the containment that is leading to an accident, and improving the safety of the nuclear power plant. Through the cooperation of different active and passive systems in the event of various accidents, the reliability of the power plant is ensured and the safety of the nuclear power plant is improved. In the present invention, active and passive thermal conduction means are used to conduct heat reduction from the reactor core, heat reduction from spent fuel, heat from storage, or heat from elements important to the safety of seawater and the atmosphere of the main heat sink, which can ensure the operation of equipment related to nuclear safety, the discharge of waste heat from the reactor or spent fuel, and maintain the integrity of the containment, in the face of both design basis and beyond design basis accidents. The active secondary circuit 1 purge and feed system includes an emergency water supply tank 10, a supply pump of1721514 of 45 emergency water 11, an evaporator 12 and a relief valve 13. The emergency water supply tank 10, the emergency water supply pump 11, the evaporator 12 and the relief valve 13 are sequentially connected by piping. A steam pipe on which the relief valve 13 is installed penetrates beyond the containment. The emergency water supply pump 11 is located below the emergency water supply tank 10. The relief valve 13 is higher than the evaporator 12. The emergency water supply tank 10, the emergency water supply pump 11 and the relief valve 13 are located outside containment 7. The evaporator 12 is located inside containment 7.The emergency water supply pump 11 carries water to the evaporator 12 through pipes. This water vaporizes into steam due to the high temperature of the containment and is then discharged through the relief valve 13. A quantity of water from the emergency water supply tank 10 should support a 72-hour operation. The emergency water supply pump 11 is an electric or pneumatic pump, and the relief valve 13 is an electric or pneumatic regulating valve that opens automatically and resets according to a set pressure that does not exceed a factory pressure of the evaporator 12. The passive secondary circuit natural circulatory system 4 includes a water tank outside containment 43, a heat exchanger of 1721514 of 45 natural circulation secondary circuit 42 and a first pneumatic fusible valve 41. The water tank outside the containment 43 is arranged on an external side wall of the containment 7. The natural circulation secondary circuit heat exchanger 42 is arranged inside the water tank outside the containment 43, and is connected to the first pneumatic fusible valve 41 by piping. The natural circulation secondary circuit heat exchanger 42 is located inside the water tank outside the containment 43, the first pneumatic fusible valve 41 is located inside the containment 7, and the evaporator 12 is located below the water tank outside the containment 43 and the natural circulation secondary circuit heat exchanger 42. The secondary circuit natural circulation heat exchanger 42 is connected to an inlet pipe and an outlet pipe of the evaporator 12 in the active secondary circuit purge and feed system 1 through pipes, so as to transfer heat from the evaporator 12 to the water tank outside the containment 43, while the first pneumatic fusible valve 41 remains closed in normal operation. The first pneumatic fusible valve 41 is set to open automatically when the temperature in containment 7 exceeds a predetermined value. A first cooling medium in the secondary circuit natural circulation heat exchanger 42 enters the evaporator 12 by action 1721514 of 45 of gravity, returns to the natural circulation heat exchanger of the secondary circuit 42 after being vaporized at high temperature in containment 7, and exchanges heat for cooling water in the water tank outside containment 43 to form a first liquid cooling medium. The active containment cooling system 2 includes a water tank inside containment 20, a containment cooling pump 21, a containment heat exchanger 22, a first sprayer 23, a second sprayer 24, and a high-pressure water supply tank outside containment 25. The water tank inside containment 20, the cooling pump of containment 21, and the heat exchanger of containment 22 are sequentially connected by pipes. The other end of the heat exchanger of containment 22 is respectively connected to the first sprayer 23 and the second sprayer, and the high-pressure water supply tank 25 is connected to the pipe that connects the heat exchanger of containment 22 and the cooling pump of containment 21 via another pipe. The cooling pump for containment 21 is at a height discharge with or lower than the bottom level of the water tank inside containment 20. 1721514 of 45 The water tank inside containment 20 is located in the lowest position of containment 7, the cooling pump of containment 21 and the heat exchanger of containment 22 are located outside the containment, and the heat exchanger of containment 22 is located above the cooling pump of containment 21. The first sprayer 23 is located in the highest position within containment 7, the second sprayer is located within containment 7 in a lower position than the first sprayer 23, and both the second sprayer and the first sprayer 23 are located at a higher height than evaporator 12. The water tank inside containment 20 is connected to the cooling pump in containment 21 via piping, and the differential head of the cooling pump in containment 21 is over 100 meters. The cooling water flowing through the hotter side of the heat exchanger in containment 22 is piped to two spray points; one of these points is the first spray point 23, and the other is the second spray point 24. The passive containment 5 thermal pipe cooling system includes an upper thermal pipe cooling system 8 and a lower thermal pipe cooling system 9. 1721514 of 45 The upper thermal pipe cooling system 8 includes a containment thermal pipe heat exchanger inside containment 50, a second pneumatic fusible valve 51 and a containment thermal pipe heat exchanger outside containment 52 located inside the water tank outside containment 43. The containment heat pipe heat exchanger inside containment 50, the second pneumatic fusible valve 51, and the containment heat pipe heat exchanger outside containment 52 are sequentially connected by piping to form a closed loop. The containment heat pipe heat exchanger inside containment 50 and the second pneumatic fusible valve 51 are located inside containment 7, the containment heat pipe heat exchanger outside containment 52 is located outside containment 7, and the containment heat pipe heat exchanger outside containment 52 is at a higher elevation than the containment heat pipe heat exchanger inside containment 50. The second pneumatic fusible valve 51 is set to open automatically when the temperature in containment 7 exceeds a predetermined value. A second cooling medium in the containment heat pipe heat exchanger outside containment 52 enters the containment heat pipe heat exchanger inside the containment. 1721514 from 45 containment 50 by the action of gravity, returns to the heat exchanger of the thermal containment pipe outside of containment 52 after being vaporized at high temperature in containment 7, and exchanges heat for cooling water in the water tank outside of containment 43 to form a second liquid cooling medium. The first vaporizer 23 has a coverage area of ​​100%; that is, the coverage area of ​​the first vaporizer is equal to a cross-sectional area of ​​the containment. The second vaporizer has a coverage area that is greater than a cross-sectional area of ​​the containment heat pipe heat exchanger within the containment 50 in the passive containment heat pipe cooling system 5. The second vaporizer 24 is located above the containment heat pipe heat exchanger within the containment 50 of the passive containment heat pipe cooling system 5. High-pressure water supply tank 25 is located outside containment 7 and has an outlet connected to a cooling pump outlet in containment 21. High-pressure water supply tank 25 is at a higher elevation than the water tank inside containment 20. A check valve is provided on an outlet pipe from the water tank inside containment 20. The top portion of high-pressure water supply tank 25 is filled with nitrogen and is pressurized. 1721514 of 45 greater than 10MPa, while a lower part of the high-pressure water supply tank 25 is filled with cooling water. When the check valve is opened, the cooling water at the bottom is forced into the vaporization structure by means of high-pressure nitrogen in the high-pressure water supply tank 25. The high-pressure water supply tank outside containment 25 can automatically provide water to vaporize a surface of the thermal pipe heat exchanger of containment 50 inside containment 7 to enhance the heat exchange effect. Additionally, a passive vaporization installation is presented for the containment thermal pipe heat exchanger within containment 50, which vaporizes water to the surface of the containment thermal pipe heat exchanger within containment 50 by means of energy storage from the high-pressure water supply tank outside containment 25 to enhance heat exchange capacity, so that the passive and active installations cooperate to accelerate heat conduction. The lower thermal pipe cooling system 9 includes a water tank thermal pipe heat exchanger inside containment 53, a water tank isolation valve outside containment 54, and an air thermal pipe heat exchanger outside 1721514 of 45, containment 55, which are sequentially connected to form a closed cycle. The lower thermal pipe cooling system 9 is lower than the upper thermal pipe cooling system 8. The air thermal pipe heat exchanger outside containment 55 and the water tank isolation valve outside containment 54 are located outside containment 7. The water tank thermal pipe heat exchanger inside containment 53 is located inside containment 7. The air thermal pipe heat exchanger outside containment 55 is at a higher height than the water tank isolation valve outside containment 54.The air thermal pipe heat exchanger outside containment 55 and the water tank isolation valve outside containment 54 are both at a higher height than the water tank thermal pipe heat exchanger inside containment 53. A third cooling medium in the containment air thermal pipe heat exchanger outside containment 55 enters the water tank thermal pipe heat exchanger inside containment 53 by gravity action, returns to the containment air thermal pipe heat exchanger outside containment 55 after being vaporized at high temperature in the containment, and exchanges heat with air outside the containment to form a third liquid cooling medium. 1721514 of 45 There are hydrocarbon media contained in the containment pipe heat exchanger within containment 50, the containment pipe heat exchanger outside containment 52, the water tank heat exchanger within containment 53, and the air heat exchanger outside containment 55, as described above. Under a certain degree of vacuum, when the temperature in containment 7 reaches more than 60°C, boiling occurs in the containment pipe heat exchanger outside containment 52 and the air heat exchanger outside containment 55. The two-phase boiling heat exchanger in the pipes solves the problem of low heat exchange efficiency in the case of an open heat exchanger, thus improving the heat exchange effect. The active shielding 3 cooling water system includes a shielding water pump 31, a heat sink heat exchanger 32, a heat sink pump 33, and a cooling tower. The shield water pump 31, the heat sink heat exchanger 32, and the containment heat exchanger 22 form a circulation circuit via piping. The shield water pump 31 introduces a medium of cooling into the heat sink heat exchanger 32 and into the containment heat exchanger 22 to cool the water. 1721514 of 45 coolant in the containment heat exchanger 22 and then the heated cooling medium returns to the heat sink heat exchanger 32. The heat sink pump 33, the cooling tower, and the heat exchanger of heat sink 32 form a circulation circuit via piping. The heat sink pump 33 pumps ambient water into the cooling tower and into the heat exchanger of heat sink 32 to cool the medium within the heat exchanger. The heated ambient water then enters the cooling tower and exchanges heat with air, and finally, the cooled ambient water returns to the heat exchanger of heat sink 32. The water pump for shield 31 is located immediately below the heat exchanger for heat sink 32, and the heat exchanger for heat sink 32 is higher than the water pump for heat sink 33. The water pump for shield 31, the heat exchanger for heat sink 32, and the water pump for heat sink 33 are located outside containment 7. The water pump for heat sink 33 is at a lower height than the heat exchanger for heat sink 32, the heat exchanger for heat sink 32 is at a lower height than the water pump for shield 31, and the water pump for shield 31 is at a lower height than or discharges with the containment heat exchanger 22, and the heat exchanger 1721514 of 45 of heat sink 32 is at a lower height than the containment heat exchanger 22. The shielding water pump 31 delivers cooling water at a temperature of 45°C or less to a cooler side of the containment heat exchanger 22 of the active containment cooling system 2, where the water, after being heated, returns to a warmer side of the heat exchanger of the heat sink 32, and then the heat sink pump 33 delivers seawater or fresh water from the cooling tower to the cooler side of the heat exchanger of the heat sink 32. The shielding water pump 31 is a centrifugal water pump, and the heat sink heat exchanger 32 is a highly compacted plate heat exchanger. The first pneumatic fusible valve 41 in the passive secondary circuit natural circulatory system 4 and the second pneumatic fusible valve 51 in the passive containment thermal pipe cooling system 5 do not require any power supply but are automatically controlled by temperature responses. As shown in Figure 2, the first pneumatic fusible valve 41 and the second pneumatic fusible valve 51 each include a main valve 47, a pneumatic actuator 48, and a fusible valve 49. The valve 1721514 of 45 main 47 is a check valve, the pneumatic actuator 48 is a pneumatic actuator in case of accidents, and the fusible valve 49 is installed in a gas passage of the actuator. The main valve 47 has a valve cavity in which the valve seat is located, and the valve seat divides the valve cavity into a liquid inlet cavity and a liquid outlet cavity, and a valve port that communicates the liquid inlet cavity with the liquid outlet cavity that is disposed above the valve seat. One end of the pneumatic actuator 48 is connected to a gas supply source in a power plant through a fusible valve 49, while the other end of the pneumatic actuator 48 penetrates the main valve 47 to connect, in a sliding manner, to the main valve 47 and has a valve core at one end and combines with the valve port of the valve seat, and the fusible valve 49 can be opened after the temperature in the containment 7 exceeds a set value so that the pneumatic actuator 48 is moved towards the valve port by the pressure of the gas transmitted from the gas supply source, until the valve core closes to the valve port. As shown in Figure 3, which is a schematic diagram that Figure 1721514 of 45 illustrates an internal interface of the fusible valve 49. The fusible valve 49 includes a valve body 410, a valve stem 40, a spring 45, and a fusible link 44. The valve body 410 is arranged with a container orifice, a gas inlet orifice N1, a gas outlet orifice N2, and an exhaust orifice N3. The gas inlet orifice N1 is connected to the gas supply source at the power plant, the gas outlet orifice N2 is connected to the pneumatic actuator 48, the exhaust orifice N3 is open to the atmosphere, the container orifice is axially arranged along the valve stem 410, and the gas inlet orifice N1, gas outlet orifice N2, and exhaust orifice N3 are axially arranged along the valve stem 410 at intervals, each in communication with the container orifice. A lower portion of the valve stem 410 extends into the reservoir bore and features a valve ball 411 attached to a wall of the reservoir bore in a sealed, sliding manner. The spring 45 is in a compressed condition and encased over an upper portion of the valve stem 410. The shear link 44 is attached to both ends of the spring 45 in the axial direction, where the spring 45 is locked by the shear link 44, thus maintaining the spring 45 in a compressed condition. The 410 valve stem has a normal condition and a condition of 1721514 of 45 high temperature, when the valve stem 410 is in the normal condition, the valve ball is located between the gas outlet port N2 and the exhaust port N3 such that the gas inlet port N1 and the gas outlet port N2 are connected while the gas outlet port N2 and the exhaust port N3 are disconnected. At this time, pressure can be transmitted from the gas source to the pneumatic actuator 48, and the main valve 47 is in the closed condition. When the valve stem 410 is in a high-temperature condition, i.e., the temperature in the containment exceeds 65°C, the fusible link 44 melts under the elevated containment temperature, causing the spring 45 to extend and push the valve stem 410 axially. This pushes the valve ball 411 between the gas inlet port N1 and the gas outlet port N2, disconnecting the gas inlet port N1 and the gas outlet port N2, while connecting the gas outlet port N2 and the exhaust port N3. The gas supply from the gas source is interrupted, and the connection between N2 and N3 allows the compressed gas to be discharged to the pneumatic actuator 48 of the main valve 47 through N3. At this point, the pneumatic actuator 48 of the main valve resets, and the valve opens automatically. In current art, the valve used on a passive system circuit is, 1721514 of 45, generally, an electric valve that needs to be opened by means of a power supply system. In the present invention, the valve based on the aforementioned melting principle is cleverly combined with the temperature increase in case of an accident so that a passage can be opened automatically, the passive action is deactivated, and the defect of opening a valve by means of a safe power supply in the traditional passive system is solved. In the present embodiment, a water baffle 46 is arranged within the water tank outside the containment 43 to divide the water tank outside the containment 43 into a first cooling compartment for cooling the naturally circulating heat exchanger of the secondary circuit 42 and a second cooling compartment for cooling the heat exchanger of the containment thermal piping outside the containment 52. When the water pressure on either side of the water baffle 46 is greater than the set value, the cooling water on the higher pressure side can push the water baffle 46 open to connect the first cooling compartment with the second cooling compartment. The two compartments are isolated by the water baffle 46 during normal operation. In the event of an accident, the secondary circuit natural circulation heat exchanger 42 and the containment thermal pipe heat exchanger 52 outside the containment are not used. 1721514 of 45 simultaneously, and the water deflector 46 isolates and prevents exchange between lower temperature water and higher temperature water, and when a differential pressure on the two sides of the water deflector 46 reaches 0.003MPa, the water deflector 46 automatically opens to ensure a shared amount of water between the two sides. As shown in Figures 4, 5, and 6, the water deflector includes a door frame 465 and at least one door leaf structure. An external side surface of the door frame 465 is sealed to the water tank outside the containment 43. The door leaf structure includes a linkage mechanism and two leaves 461. The ends of the two leaves 461, which are close to each other, are hinged to the door structure 465, and a sealing ring 464 is disposed on an external side surface 461 of each leaf. The linkage mechanism includes two coupling rods 462 and a constant-force spring 463.The two coupling rods 462 correspond to the two leaves of the water baffle 461. The ends of the two coupling rods 462 furthest apart are respectively hinged to the corresponding leaves 461, and the ends of the two coupling rods 462 closest to each other are respectively connected to two ends of the constant force spring 463. When the water pressure on any side of the water baffle 46 is greater than the spring force of the constant force spring 463, the cooling water on the higher pressure side will be released. 1721514 of 45 can push the leaf 461b to rotate around a hinge point so that by means of the sealing ring 464 in a sealed manner, the leaf 461 and the door frame 465 are connected and the adjacent leaves 461 are connected, or the leaf 461 and the frame 465 are disconnected from each other, and the adjacent leaves 461 are disconnected from each other. When the water baffle is opened, water from the water tank outside containment 43 flows from a higher liquid level side to a lower liquid level side, until an balanced water level is achieved. In current art, annular water tanks outside the containment mostly have a communicative structure, and the higher temperature of the water tank outside the containment after an accident will cause the heat exchange performance to decrease or even expose or leak the passive heat exchanger.According to the present invention, the water tank outside the containment with the water baffle is designed to employ a partition for isolation in the event of a base accident to ensure isolation between the higher temperature water and the lower temperature water on the two sides of the partition, and when a differential pressure between the two sides of the partition reaches a set value, the partition automatically opens to ensure a shared quantity of water between the two sides, thus avoiding the problems of early water evaporation in an early stage of an accident and insufficient water. 1721514 of 45 in a final stage of the accident. In the event of a design-based accident, and when the primary circuit pressure limit is intact, heat can be discharged to a main air-heat sink via the secondary circuit's purge and feed system. If the primary circuit is damaged, the heat can be transferred to the shielding water cooling system 3 via the active containment cooling system 2, and then conducted to the seawater and atmosphere of the main heat sink. In the event of an accident exceeding the station's design-based blackout, and when the primary circuit pressure limit is intact, the heat can be conducted to the main atmosphere-heat sink via the passive secondary circuit's natural circulation system 4.When the primary circuit is damaged and cannot establish natural circulation, or even when the reactor core is melted, the heat from containment 7 can be conducted from containment 7 to the water tank outside containment 43 by means of the containment thermal pipe heat exchanger within containment 50 of the passive containment thermal pipe cooling system 5, and then conducted to the main atmosphere heat sink by means of evaporation and heat exchange. It should be noted that the implementations described above are merely exemplary embodiments for the purpose of illustrating the principle of the invention and that the invention is not limited to them. 1721514 of 45, as understood in the art, it will be evident that various modifications and variations of the invention can be made without departing from the spirit or essence of the invention. Such modifications and variations should also be considered as included within the scope of protection of the invention.

Claims

1. A main heat sink system for the active and passive cooperative cooling of a nuclear power station, characterized in that it comprises: an active secondary circuit purge and feed system (1); an active containment cooling system (2); an active protection cooling water system (3); a passive secondary circuit natural circulation system (4); and a passive containment heat pipe cooling system (5); wherein the active secondary circuit purge and feed system (1) penetrates a containment (7) to be fixedly connected below the passive secondary circuit natural circulation system, wherein the active containment cooling system penetrates the containment (7) to be fixedly connected above the active protection cooling water system outside the containment (7),and the passive containment heat tube cooling system includes an upper heat tube cooling system and a lower heat tube cooling system, which are arranged respectively in an upper and lower part of the containment (7); the passive secondary circuit natural circulation system includes an outlet containment water tank (43), a secondary circuit natural circulation heat exchanger (42), and a pneumatic fuse valve A (41), wherein the secondary circuit natural circulation heat exchanger (42) and the pneumatic fuse valve A (41) are connected via piping and are connected to an inlet pipe and an outlet pipe of an evaporator (12) in the active secondary circuit feed and bleed system via piping,The secondary circuit natural circulation heat exchanger (42) is located inside the outlet containment water tank (43), and the pneumatic fuse valve A (41) is located inside the containment (7) and is fixedly installed below the outlet containment water tank (43) and the secondary circuit natural circulation heat exchanger (42). The upper heat tube cooling system includes a containment heat tube heat exchanger (50), a pneumatic fuse valve B (51), and an outlet containment heat tube heat exchanger (52) that are sequentially connected via piping to form a closed cycle, wherein the containment heat tube heat exchanger (50) and the pneumatic fuse valve B (51) are located inside the containment (7).the outlet containment heat tube heat exchanger (52) is located outside the containment (7), the outlet containment heat tube heat exchanger (52) is at a higher height than the pneumatic fuse valve b (51) and the pneumatic fuse valve b (51) is at a higher height than the containment heat tube heat exchanger (50); the pneumatic fuse valve A (41) or the pneumatic fuse valve B (51) includes a main valve (47), a pneumatic actuator (48) and a fuse valve (49), wherein the pneumatic actuator (48) is installed on the main valve (47), and the fuse valve (49) is connected to the pneumatic actuator (48) through piping; and the main valve (47) is a pneumatic shut-off valve,The pneumatic actuator (48) is a crashed pneumatic actuator and the fusible valve (49) is installed in a gas path of the actuator; the fusible valve (49) is provided with three pipe ports N1, N2 and N3, where N1 is a gas inlet port connected to the gas supply pipes in a power plant, N2 is a gas outlet port connected to the pneumatic actuator (48) and N3 is an exhaust port in communication with the atmosphere; and the fusible valve (49) includes a valve stem (40), a fusible link (44) and a spring (45), wherein the spring (45) is installed around the valve stem (40), the fusible link (44) is located on one side of the spring (45) and connected to an upper and lower part of the spring (45), the valve stem (40) is in the upper position under normal operating conditions,The valve stem (40) compresses the spring (45) located at the top to connect ports N1 and N2, in which case a gas source pressure can be transmitted to the pneumatic actuator (48), so that the main valve (47) is in a closed state in which the spring (45) is blocked by the fusible link (44); when the temperature in the containment (7) is above 65°C, the fusible link (44) is automatically disconnected and the spring (45) pushes the valve stem (40) to the lower position, in which case N2 and N3 are connected while N1 is disconnected; and disconnecting N1 cuts off the gas supply from the gas source, while connecting N2 and N3 can discharge compressed gas into the pneumatic actuator (48) of the main valve (47) through N3, in which case the pneumatic actuator (48) of the main valve is reset and the valve opens automatically. 21 Claims follow,