nuclear reactor

Abstract

The present invention relates to a nuclear reactor, which comprises a reactor pressure vessel, a primary circuit and a spray system. A reactor core is installed in the reactor pressure vessel; the primary circuit is installed on the reactor pressure vessel, and the primary circuit comprises a heat pipe section; the spray system comprises a water supply tank, a spray pipeline and a pressure balance pipeline. The water supply tank is arranged above the reactor pressure vessel and is used to accommodate air and cooling water. The water supply tank is connected to the interior of the reactor pressure vessel through the spray pipeline. One end of the pressure balance pipeline is connected to the heat pipe section, and the other end is connected to the air in the water supply tank. A first check valve is provided on the pressure balance pipeline, and the first check valve is used to prevent the air in the water supply tank from flowing into the primary circuit. When the rupture size of the primary circuit is within a preset range, the spray system is in a first state, and the cooling water in the water supply tank flows into the reactor pressure vessel through the spray pipeline under the action of gravity.

Description

Technical Field

[0001] The present invention relates to the technical field of nuclear power plants, in particular to a nuclear reactor. Background Art

[0002] A nuclear reactor consists of a containment vessel, a reactor pressure vessel, a core, and a primary circuit. The core is housed within the reactor pressure vessel, which is housed within the containment vessel. The primary circuit transports cooling water, which carries the heat released by the core out of the reactor pressure vessel and into the steam generators. If a primary circuit ruptures and a loss of cooling water occurs, the cooling water in the reactor pressure vessel decreases, causing the reactor core temperature to rise rapidly. If not cooled promptly, the temperature and pressure of the reactor pressure vessel could rise, leading to a more serious accident. Summary of the Invention

[0003] Based on this, it is necessary to provide a nuclear reactor to address the problem of lowering the reactor temperature.

[0004] A nuclear reactor comprising:

[0005] The reactor pressure vessel, which houses the core;

[0006] a primary circuit, mounted on the reactor pressure vessel, the primary circuit comprising a heat pipe segment;

[0007] A spray system, comprising a water supply tank, a spray pipeline, and a pressure balance pipeline. The water supply tank is arranged above the reactor pressure vessel and is used to accommodate air and cooling water. The water supply tank is connected to the interior of the reactor pressure vessel through the spray pipeline. One end of the pressure balance pipeline is connected to the hot pipe section, and the other end is connected to the air in the water supply tank. A first check valve is provided on the pressure balance pipeline, and the first check valve is used to prevent the air in the water supply tank from flowing into the primary circuit.

[0008] When the rupture size of the primary circuit is within a preset range and the primary circuit is not depressurized or the depressurization is slow, the spray system is in the first state, and the cooling water in the water supply tank flows into the reactor pressure vessel through the spray pipeline under the action of gravity;

[0009] When the rupture size of the primary circuit is larger than the preset range, the primary circuit is quickly depressurized, the air pressure in the water supply tank is greater than the air pressure in the hot pipe section, the spray system is in the second state, and the cooling water in the water supply tank flows into the reactor pressure vessel through the spray pipeline under the action of gravity and pressure.

[0010] In one embodiment, a flow limiting valve is provided on the spray pipeline, and the flow limiting valve is used to limit the flow rate of cooling water in the spray pipeline.

[0011] In one embodiment, the spray system further includes a flow-increasing pipeline and a bursting valve provided on the flow-increasing pipeline, wherein the bursting valve is used to control the connection or closing of the flow-increasing pipeline, and the bursting valve is connected to the spray pipeline in parallel with the flow-limiting valve through the flow-increasing pipeline;

[0012] When the spray system is in the second state, the flow-increasing pipeline is connected, so that the cooling water in the water-making tank can flow into the reactor pressure vessel through the flow-increasing pipeline.

[0013] In one embodiment, the reactor pressure vessel, the primary circuit, and the spray system are all disposed within the containment vessel of the nuclear reactor;

[0014] A stack pit is provided on the inner wall of the containment vessel, and the reactor pressure vessel is at least partially accommodated in the stack pit. The height of the top of the stack pit is the same as the height of the upper edge of the active section of the core. The stack pit is used to collect the coolant lost in the first circuit and the condensed water in the containment vessel.

[0015] In one embodiment, the inner bottom wall of the containment shell includes a first connecting portion and a recessed portion connected to each other. The recessed portion extends in a direction away from the upper top wall of the containment shell to form the stack pit. The first connecting portion includes a first connecting end and a second connecting end. The first connecting end is used to connect to the inner side wall of the containment shell, and the second connecting end is used to connect to the top of the recessed portion. The height of the first connecting end is greater than the height of the second connecting end.

[0016] In one embodiment, a pressure relief valve is installed on the heat pipe section, and the pressure relief valve is used to relieve the pressure of the heat pipe section. A reflux piece is provided on the bottom wall of the reactor pressure vessel, and the reflux piece is used to allow the liquid in the reactor pit to flow into the reactor pressure vessel to cool the core when the pressure in the reactor pressure vessel is lower than the pressure in the containment vessel.

[0017] In one embodiment, it also includes a connected cooling water tank and a heat exchanger, wherein the cooling water tank is installed on the outer wall of the containment shell and is used to contain coolant, and the heat exchanger is arranged in the containment shell and is used to reduce the gas temperature in the containment shell.

[0018] In one embodiment, in an initial state, the volume occupied by air in the water replenishing tank is 4%-10% of the total volume of the water replenishing tank.

[0019] In one embodiment, a second check valve is provided on the spray pipeline, and the second check valve is used to prevent backflow when the air pressure in the reactor pressure vessel is greater than the air pressure in the water supply tank.

[0020] In one embodiment, a spray head is installed at the end of the spray pipeline extending into the reactor pressure vessel.

[0021] Beneficial effects of the present invention:

[0022] The nuclear reactor described above has a core installed within a reactor pressure vessel, and a primary circuit installed within the reactor pressure vessel reduces the temperature within the reactor pressure vessel. A water-making tank is positioned above the reactor pressure vessel and contains air and cooling water. Therefore, the cooling water within the water-making tank flows into the reactor pressure vessel through a spray line under its own gravity, thereby reducing the core temperature. A pressure-balancing line connects the hot pipe section and the air within the water-making tank, ensuring that the air pressure within the hot pipe section is equal to that within the water-making tank. A first check valve is provided on the pressure-balancing line to prevent air within the water-making tank from flowing into the primary circuit. When the rupture size of the primary circuit is within the preset range, the air pressure in the water supply tank and the air pressure in the primary circuit do not fluctuate much, that is, the primary circuit has not been depressurized or the depressurization is slow, so the spray system is in the first state, and the cooling water in the water supply tank flows into the reactor pressure vessel through the spray pipe under the action of gravity, thereby reducing the temperature of the core; when the rupture size of the primary circuit is larger than the preset range, that is, the primary circuit is quickly depressurized, the air pressure in the water supply tank is greater than the air pressure in the hot pipe section, so the spray system is in the second state. At this time, because the air pressure in the water supply tank is greater than the air pressure in the primary circuit, A first check valve is installed on the pressure balance pipeline. The air above the make-up water tank cannot flow back into the hot pipe section. The air in the make-up water tank can only act downward in the make-up water tank, thereby pressing the cooling water in the make-up water tank into the spray pipeline. Therefore, in addition to being affected by its own gravity, the water in the make-up water tank is also affected by the air pressure above the make-up water tank. Both gravity and air pressure act downward, so that the cooling water in the make-up water tank flows into the reactor pressure vessel through the spray pipeline under the action of gravity and pressure, which speeds up the flow rate of the cooling water and further improves the efficiency of reducing the core temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic structural diagram of a nuclear reactor provided in an embodiment of the present invention.

[0024] In the picture:

[0025] 100. Reactor pressure vessel; 110. Reactor core; 120. Reflux components;

[0026] 200, primary circuit; 210, cold pipe section; 220, hot pipe section; 221, pressure relief valve;

[0027] 300, sprinkler system; 310, water supply tank; 320, sprinkler pipeline; 321, flow limiting valve; 322, second electric valve; 323, second check valve; 330, pressure balancing pipeline; 331, first check valve; 332, first electric valve; 340, flow increasing pipeline; 341, burst valve;

[0028] 400, containment vessel; 410, first connection portion; 420, recessed portion; 430, second connection portion;

[0029] 500. Cooling water tank;

[0030] 600, heat exchanger;

[0031] 700. Steam generator. DETAILED DESCRIPTION

[0032] To make the above-mentioned objects, features, and advantages of the present invention more readily apparent, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. The following description sets forth numerous specific details to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art may make similar modifications without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0033] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0034] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0035] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two components, or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0036] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it 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 intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0037] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

[0038] The embodiment of the present invention provides a nuclear reactor, such as Figure 1As shown, the nuclear reactor includes a reactor pressure vessel 100, a primary circuit 200 and a spray system 300. A core 110 is installed in the reactor pressure vessel 100; the primary circuit 200 is installed on the reactor pressure vessel 100, and the primary circuit 200 includes a heat pipe section 220; the spray system 300 includes a water supply tank 310, a spray pipeline 320 and a pressure balance pipeline 330. The water supply tank 310 is arranged above the reactor pressure vessel 100 and is used to accommodate air and cooling water. The water supply tank 310 is connected to the interior of the reactor pressure vessel 100 through the spray pipeline 320. One end of the pressure balance pipeline 330 is connected to the heat pipe section 220, and the other end is connected to the air in the water supply tank 310. A first check valve 331 is provided on the pressure balance pipeline 330, and the first check valve 331 is used to prevent the air in the water supply tank 310 from flowing into the primary circuit 200; when the rupture size of the primary circuit 200 is within the preset range, the spray system 300 is in the first state, and the cooling water in the water supply tank 310 flows into the reactor pressure vessel 100 through the spray pipeline 320 under the action of gravity; when the rupture size of the primary circuit 200 is greater than the preset range and the air pressure in the water supply tank 310 is greater than the air pressure in the hot pipe section 220, the spray system 300 is in the second state, and the cooling water in the water supply tank 310 flows into the reactor pressure vessel 100 through the spray pipeline 320 under the action of gravity and pressure.

[0039] The above-described nuclear reactor has a core 110 installed within a reactor pressure vessel 100. A primary circuit 200 is installed on the reactor pressure vessel 100 to reduce the temperature within the reactor pressure vessel 100. A water makeup tank 310 is positioned above the reactor pressure vessel 100 and contains air and cooling water. Therefore, the cooling water within the water makeup tank 310 flows into the reactor pressure vessel 100 through a spray line 320 under its own gravity, thereby reducing the temperature of the core 110. A pressure equalization line 330 connects the hot pipe section 220 and the air within the water makeup tank 310, thereby ensuring that the air pressure within the hot pipe section 220 is equal to that within the water makeup tank 310. A first check valve 331 is provided on the pressure equalization line 330 to prevent air within the water makeup tank 310 from flowing into the primary circuit 200. When the rupture size of the primary loop 200 is within the preset range, the air pressure in the water supply tank 310 and the air pressure in the primary loop 200 do not fluctuate much, that is, the primary loop 200 is not depressurized or the depressurization is slow, so the spray system 300 is in the first state, and the cooling water in the water supply tank 310 flows into the reactor pressure vessel 100 through the spray pipe 320 under the action of gravity, thereby reducing the temperature of the core 110; when the rupture size of the primary loop 200 is larger than the preset range, and the air pressure in the water supply tank 310 is greater than the air pressure in the hot pipe section 220, that is, the primary loop 200 is quickly depressurized, the spray system 300 is in the second state. At this time, because the air pressure in the water supply tank 310 is greater than the air pressure in the hot pipe section 220, pressure, and a first check valve 331 is installed on the pressure balance pipeline 330. The air above the make-up water tank 310 cannot flow back into the hot pipe section 220, so the gas in the make-up water tank can only act downward in the make-up water tank 310, thereby pressing the cooling water in the make-up water tank 310 into the spray pipeline 320. Therefore, in addition to being affected by its own gravity, the water in the make-up water tank 310 is also affected by the air pressure above the make-up water tank 310. Both gravity and air pressure act downward, so that the cooling water in the make-up water tank 310 flows into the reactor pressure vessel 100 through the spray pipeline 320 under the action of gravity and pressure, thereby accelerating the flow rate of the cooling water and further improving the efficiency of reducing the temperature of the core 110.

[0040] It should be noted that, because the primary circuit 200 is connected to the reactor pressure vessel 100 , the air pressure in the water supply tank 310 is greater than the air pressure in the heat pipe section 220 , that is, the air pressure in the water supply tank 310 is greater than the air pressure in the reactor pressure vessel 100 .

[0041] In some embodiments, as Figure 1As shown, the primary loop 200 also includes a cold pipe section 210 connected to the hot pipe section 220. The hot pipe section 220 is connected to the steam generator 700. The hot pipe section 220, the cold pipe section 210 and the steam generator 700 cooperate with each other to reduce the temperature in the reactor pressure vessel 100. The layout position and specific usage method of the primary loop 200 are common knowledge in the field and will not be elaborated here.

[0042] In some embodiments, as Figure 1 As shown, a first electric valve 332 is provided on the pressure balancing pipeline 330 . The first electric valve 332 is used to control the connection and disconnection of the pressure balancing pipeline 330 . The first electric valve 332 is in a normally open state.

[0043] In some embodiments, as Figure 1 As shown, a flow limiting valve 321 is provided on the spray line 320. The flow limiting valve 321 is used to limit the flow rate of the cooling water in the spray line 320. The flow limiting valve 321 is provided on the spray line 320 to limit the flow rate of the cooling water in the spray line 320. When the spray system 300 is in the first state, the flow limiting valve 321 limits the flow rate of the cooling water in the spray line 320. This prevents the water in the makeup water tank 310 from being rapidly depleted, maintains long-term top spray cooling at the top of the core 110, and facilitates response to a loss of coolant accident when the breach size of the primary circuit 200 is within a preset range.

[0044] In some embodiments, as Figure 1 As shown, a second electric valve 322 is provided on the spray pipeline 320. The second electric valve 322 is used to control the connection and disconnection of the spray pipeline 320. The second electric valve 322 is in a normally open state.

[0045] In some embodiments, as Figure 1 As shown, the spray line 320 is provided with a second check valve 323. The second check valve 323 is used to prevent backflow when the air pressure within the reactor pressure vessel 100 is greater than the air pressure within the makeup water tank 310. By providing the second check valve 323 on the spray line 320, when the air pressure within the reactor pressure vessel 100 is greater than the air pressure within the makeup water tank 310, the gas within the reactor pressure vessel 100 will not flow back into the makeup water tank 310, thereby allowing the water in the makeup water tank 310 to flow smoothly into the spray line 320.

[0046] In some embodiments, as Figure 1As shown, the spray system 300 also includes a flow-increasing pipeline 340 and a bursting valve 341 arranged on the flow-increasing pipeline 340. The bursting valve 341 is used to control the connection or closing of the flow-increasing pipeline 340. The bursting valve 341 is connected to the spray pipeline 320 in parallel with the flow-limiting valve 321 through the flow-increasing pipeline 340; when the spray system 300 is in the second state, the flow-increasing pipeline 340 is connected so that the cooling water in the water-making tank 310 can flow into the reactor pressure vessel 100 through the flow-increasing pipeline 340. By setting up a flow-increasing pipeline 340 and installing a bursting valve 341 on the flow-increasing pipeline 340, when the rupture size of the primary circuit 200 is larger than a preset range and the air pressure in the water-making tank 310 is greater than the air pressure in the hot pipe section 220, the pressure difference between the water-making tank 310 and the primary circuit 200 will cause the bursting valve 341 to open. The cooling water in the water-making tank 310 is subjected to the dual effects of gravity and the air pressure above it, and flows into the reactor pressure vessel 100 in two ways. One path of cooling water flows directly into the reactor pressure vessel 100 through the spray pipeline 320, and the other path of cooling water flows into the reactor pressure vessel 100 through the flow-increasing pipeline 340 in sequence.

[0047] More specifically, if Figure 1 As shown, one end of the flow-increasing line 340 is connected to a first portion of the spray line 320 upstream of the flow-limiting valve 321, and the other end of the flow-increasing line 340 is connected to a second portion of the spray line 320 downstream of the flow-limiting valve 321. When the spray system 300 is in the second state, cooling water in the makeup water tank 310 can flow into the reactor pressure vessel 100 in sequence through the first portion of the spray line 320 upstream of the flow-limiting valve 321, the flow-increasing line 340, and the second portion of the spray line 320 downstream of the flow-limiting valve 321. When the breach size of the primary circuit 200 exceeds a preset range, the cooling water in the primary circuit 200 is rapidly lost, the core 110 is exposed and rapidly heats up, and the flow-increasing line 340 automatically opens under pressure, allowing both cooling water lines to flow into the reactor pressure vessel 100. This increases the volume of cooling water flowing in, improves cooling efficiency, and prevents melting of the core 110.

[0048] It will be appreciated that when the spray system 300 is in the second state, i.e., the size of the breach in the primary circuit 200 is larger than a preset range, the air pressure in the primary circuit 200 is lower than the air pressure in the makeup water tank 310. The pressure differential between the makeup water tank 310 and the primary circuit 200 can cause the bursting valve 341 to open, thereby allowing cooling water to flow into the reactor pressure vessel 100 through the flow-increasing pipeline 340. Opening the bursting valve 341 in response to a pressure differential is a conventional technique in the art, and therefore the specific installation structure of the bursting valve 341 will not be described in detail herein.

[0049] In some embodiments, in the initial state, the space inside the water supply tank 310 includes a gas space for accommodating air and a liquid space for accommodating cooling water, wherein the gas space is located above the liquid space. The reactor pressure vessel 100 is connected to the liquid space of the water supply tank 310 through the spray line 320, and the heat pipe section 220 of the first circuit is connected to the gas space of the water supply tank 310 through the pressure balance line 330. Since a gas space for accommodating air is reserved in the water supply tank 310, the reserved air can be used as a driving pressure head when the spray line 320 is in the second state. It should be noted that the initial state refers to the state when the water supply tank 310 is installed, that is, the state when the water supply tank 310 has not yet been used. The initial state mentioned below will also be explained in this way and will not be repeated.

[0050] Furthermore, in some embodiments, in the initial state, the volume occupied by air in the water replenishment tank 310 is 4%-10% of the total volume of the water replenishment tank 310. That is, the volume of the air space in the water replenishment tank 310 accounts for 4%-10% of the total volume of the water replenishment tank 310. This can increase the pressure head for driving the spray pipe 320 in the second state. For example, if the volume occupied by air in the water replenishment tank 310 is 4% of the total volume of the water replenishment tank 310, the specific calculation is as follows:

[0051] When the primary circuit 200 is fully depressurized, the water in the makeup water tank 310 can be discharged into the primary circuit 200 under the action of the pressurized gas above. During normal operation of the nuclear reactor, the pressure in the primary circuit 200 is 15.5 MPa. Because the first check valve 331 is installed in the pressure equalization line 330, when a breach occurs in the primary circuit 200, the initial pressure of the gas above the makeup water tank 310 remains at 15.5 MPa. If the volume of the fully pressurized makeup water tank 310 is V1 and the volume of the air space is V2, according to the ideal gas equation:

[0052] P1V1=nRT=P2V2

[0053]

[0054] Among them, P1 is the pressure after the primary circuit 200 is completely depressurized. Because when the primary circuit 200 is breached, the maximum pressure of the containment 400 is 0.55 MPa, it is conservatively considered that the pressure after the primary circuit 200 is depressurized is 0.55 MPa; P2 is the initial partial pressure of the upper air in the water supply tank 310, which is 15.5 MPa.

[0055] In some embodiments, a nozzle is installed at the end of the spray pipe 320 extending into the reactor pressure vessel 100. By providing the nozzle, the spray range of the cooling water in the reactor pressure vessel 100 is made larger. Moreover, when a loss of coolant accident occurs, the core 110 is exposed first and heats up. The temperature of the core 110 is higher at the top and lower at the bottom. Spray cooling at the top of the core 110 can effectively suppress the temperature peak of the core 110. With the use of accident-resistant fuel, the melting point of the cladding has been greatly improved, and the oxidation rate has been greatly reduced in a high-temperature water vapor environment. The temperature of the core 110 can be maintained within the limit by top spraying. There is no need to inject a large amount of cooling water to flood the core 110 again in the short term after the accident, thereby saving the water volume of the mitigation system and providing sufficient time for the activation of conventional active equipment.

[0056] In some embodiments, as Figure 1 As shown, the reactor pressure vessel 100, the primary circuit 200, and the spray system 300 are all disposed within the containment vessel 400 of the nuclear reactor. A pit is provided on the inner wall of the containment vessel 400, and the reactor pressure vessel 100 is at least partially contained within the pit. The top of the pit is at the same height as the upper edge of the active section of the core 110. The pit is used to collect coolant lost from the primary circuit 200 and condensed water within the containment vessel 400. By providing the pit on the inner wall of the containment vessel 400, the reactor pressure vessel 100 is at least partially contained within the pit. When the pit collects coolant lost from the primary circuit 200 and condensed water within the containment vessel 400, it can be used to cool the reactor pressure vessel 100.

[0057] It should be noted that the height of the top of the pit is the same as the height of the upper edge of the active section of the core 110 , which reduces the depth of the pit and thus reduces the difficulty of setting up the pit.

[0058] In some embodiments, as Figure 1 As shown, the inner bottom wall of the containment vessel 400 includes a first connecting portion 410 and a recessed portion 420, which are connected. The recessed portion 420 extends away from the upper top wall of the containment vessel 400 to form a stack pit. The first connecting portion 410 includes a first connecting end and a second connecting end. The first connecting end is used to connect to the inner side wall of the containment vessel 400, and the second connecting end is used to connect to the top of the recessed portion 420. The height of the first connecting end is greater than that of the second connecting end. The stack pit is set on the inner bottom wall of the containment vessel 400, and the first connecting portion 410 is set on one side of the stack pit in an inclined state. This facilitates the flow of cooling liquid from the containment vessel 400 into the stack pit.

[0059] Furthermore, if Figure 1As shown, the inner bottom wall of the containment vessel 400 may further include a second connecting portion 420. The side of the recessed portion 420 facing away from the first connecting portion 410 is connected to the inner sidewall of the containment vessel 400 via the second connecting portion 420. In some embodiments, the second connecting portion may be inclined, and its inclination direction is opposite to that of the first connecting portion 410. The first connecting portion 410 and the second connecting portion 420, which are inclined toward the stack pit, are disposed on either side of the stack pit, thereby further facilitating the flow of cooling water from the containment vessel 400 into the stack pit.

[0060] It should be noted that, in some embodiments, the side of the recessed portion 420 facing away from the first connecting portion 410 may also be directly connected to the inner wall of the containment vessel 400. In addition, in some embodiments, the first connecting portion and / or the second connecting portion may also be arranged horizontally, which is not limited here.

[0061] Specifically, if Figure 1 As shown, a pressure relief valve 221 is installed on the heat pipe section 220 to relieve pressure from the heat pipe section 220. A reflux member 120 is provided on the bottom wall of the reactor pressure vessel 100. When the pressure within the reactor pressure vessel 100 is lower than the pressure within the containment vessel 400, the reflux member 120 allows liquid in the reactor pit to flow into the reactor pressure vessel 100 to cool the core 110. During normal operation of the nuclear reactor, the pressure within the reactor pressure vessel 100 is higher than the pressure within the containment vessel 400. At this time, the reflux member 120 automatically closes and will not be accidentally opened. When an accident occurs, for example, a rupture occurs in the primary circuit 200, the coolant in the primary circuit 200 is lost, and the reactor pit is flooded, the pressure of the hot pipe section 220 is quickly relieved through the pressure relief valve 221 on the hot pipe section 220. The pressure in the reactor pressure vessel 100 is lower than the pressure in the containment vessel 400. The reflux component 120 automatically opens under the action of the pressure difference, thereby establishing a re-flooding flow channel for the core 110. The cooling liquid in the reactor pit can flow into the reactor pressure vessel 100, thereby cooling the core 110, ensuring the re-flooding of the core 110, and eliminating the core 110 melting accident.

[0062] More specifically, in some embodiments, the return member 120 is a check valve. During normal nuclear reactor operation, the pressure within the reactor pressure vessel 100 is greater than the pressure within the containment vessel 400. At this point, the check valve automatically closes and prevents accidental opening. In the event of an accident, such as a breach in the primary circuit 200, loss of coolant in the primary circuit 200, or flooding of the reactor pit, the pressure within the reactor pressure vessel 100 becomes lower than the pressure within the containment vessel 400. The check valve automatically opens due to the pressure differential.

[0063] In some embodiments, as Figure 1As shown, the containment vessel 400 further includes a cooling water tank 500 and a heat exchanger 600 connected thereto. The cooling water tank 500 is mounted on the outer wall of the containment vessel 400 and is used to hold coolant. The heat exchanger 600 is disposed within the containment vessel 400 and is used to reduce the temperature of the gas within the containment vessel 400. By mounting the cooling water tank 500 on the outer wall of the containment vessel 400 and being used to hold coolant, and mounting the heat exchanger 600 within the containment vessel 400 and being connected thereto, when the temperature within the containment vessel 400 rises, the heat exchanger 600 is used to reduce the temperature of the gas within the containment vessel 400, thereby reducing the temperature within the containment vessel 400 and improving the operational safety of the nuclear reactor.

[0064] The implementation of the aforementioned spray system 300 does not require manual operation or external power supply. After an accident occurs, it can automatically operate based on the water level and pressure of the primary circuit 200, automatically matching the water injection flow rate requirements, making it a highly reliable passive safety system. The nuclear reactor provided in this application uses a spray system plus passive core recirculation cooling (i.e., the cooling liquid in the reactor pit can flow back into the reactor pressure vessel 100), which can effectively cope with extreme conditions such as the Fukushima incident in Japan and can prevent the core 110 from melting even in the event of a prolonged power outage.

[0065] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0066] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A nuclear reactor, characterized in that: include: A reactor pressure vessel (100) having a reactor core (110) installed therein; A primary circuit (200) is installed on the reactor pressure vessel (100), and the primary circuit (200) includes a heat pipe section (220); A spray system (300) comprises a water supply tank (310), a spray pipeline (320) and a pressure balance pipeline (330). The water supply tank (310) is arranged above the reactor pressure vessel (100) and is used to accommodate air and cooling water. The water supply tank (310) is communicated with the interior of the reactor pressure vessel (100) through the spray pipeline (320). One end of the pressure balance pipeline (330) is communicated with the hot pipe section (220), and the other end is communicated with the air in the water supply tank (310). A first check valve (331) is provided on the pressure balance pipeline (330). The first check valve (331) is used to prevent the air in the water supply tank (310) from flowing into the primary circuit (200). When the breach size of the primary circuit (200) is within a preset range, the spray system (300) is in a first state, and the cooling water in the water supply tank (310) flows into the reactor pressure vessel (100) through the spray pipeline (320) under the action of gravity; When the breach size of the primary circuit (200) is greater than the preset range, and the air pressure in the water supply tank (310) is greater than the air pressure in the hot pipe section (220), the spray system (300) is in a second state, and the cooling water in the water supply tank (310) flows into the reactor pressure vessel (100) through the spray pipeline (320) under the action of gravity and pressure; A flow limiting valve (321) is provided on the spray pipeline (320), and the flow limiting valve (321) is used to limit the flow rate of cooling water in the spray pipeline (320); The spray system (300) further comprises a flow-increasing pipeline (340) and a bursting valve (341) provided on the flow-increasing pipeline (340), wherein the bursting valve (341) is used to control the connection or closing of the flow-increasing pipeline (340), and the bursting valve (341) is connected to the spray pipeline (320) in parallel with the flow-limiting valve (321) through the flow-increasing pipeline (340); When the spray system (300) is in the second state, the flow-increasing pipeline (340) is connected, so that the cooling water in the water-making tank (310) can flow into the reactor pressure vessel (100) through the flow-increasing pipeline (340).

2. The nuclear reactor according to claim 1, characterized in that The reactor pressure vessel (100), the primary circuit (200), and the spray system (300) are all arranged in the containment vessel (400) of the nuclear reactor; A stack pit is provided on the inner wall of the containment vessel (400), the reactor pressure vessel (100) is at least partially accommodated in the stack pit, and the top of the stack pit is at the same height as the upper edge of the active section of the core (110), and the stack pit is used to collect the coolant lost from the primary circuit (200) and the condensed water in the containment vessel (400).

3. The nuclear reactor according to claim 2, characterized in that The inner bottom wall of the containment shell (400) includes a first connecting portion (410) and a recessed portion (420) connected to each other, the recessed portion (420) extending in a direction away from the upper top wall of the containment shell (400) to form the stack pit, the first connecting portion (410) includes a first connecting end and a second connecting end, the first connecting end is used to be connected to the inner side wall of the containment shell (400), the second connecting end is used to be connected to the top end of the recessed portion (420), and the height of the first connecting end is greater than the height of the second connecting end.

4. The nuclear reactor according to claim 2, characterized in that A pressure relief valve (221) is installed on the heat pipe section (220), and the pressure relief valve (221) is used to relieve the pressure of the heat pipe section (220). A reflux member (120) is provided on the bottom wall of the reactor pressure vessel (100), and the reflux member (120) is used to allow the liquid in the reactor pit to flow into the reactor pressure vessel (100) to cool the reactor core (110) when the pressure in the reactor pressure vessel (100) is lower than the pressure in the containment vessel (400).

5. The nuclear reactor according to claim 2, characterized in that The invention also includes a cooling water tank (500) and a heat exchanger (600) connected to each other. The cooling water tank (500) is installed on the outer wall of the containment shell (400) and is used to contain coolant. The heat exchanger (600) is arranged in the containment shell (400) and is used to reduce the gas temperature in the containment shell (400).

6. The nuclear reactor according to claim 1, characterized in that In the initial state, the volume occupied by air in the water supply tank (310) is 4%-10% of the total volume of the water supply tank (310).

7. The nuclear reactor according to claim 1, characterized in that A second check valve (323) is provided on the spray pipeline (320), and the second check valve (323) is used to prevent backflow when the air pressure in the reactor pressure vessel (100) is greater than the air pressure in the water supply tank (310).

8. The nuclear reactor according to claim 1, characterized in that A spray head is installed at the end of the spray pipeline (320) extending into the reactor pressure vessel (100).

Images