Passive containment cooling system and reactor system

Abstract

The present application relates to nuclear power technology field, provide a kind of passive containment cooling system and reactor system, the passive containment cooling system includes: storage box, heat exchanger and cooling water pipeline;Storage box is suitable for being arranged in containment, for storing cooling water;Heat exchanger is arranged in the containment, the heat exchanger includes first state and second state;Cooling water pipeline is communicated the storage box and the heat exchanger, to form heat exchange circulation loop;In the first state, the heat exchanger is filled with inorganic salt;In the second state, the heat exchanger is the hydration inorganic salt solution of cooling water and inorganic salt.In the present application, inorganic salt hydration heat storage is combined with natural circulation cooling, realizes the efficient cooling of containment passive cooler full cycle, eliminates the short board problem of transmission passive cooler initial cooling, improves the integrity of the last safety barrier of reactor system.

Description

Technical Field

[0001] This invention relates to the field of nuclear power technology, and in particular to a passive containment cooling system and a reactor system. Background Technology

[0002] In a pressurized water reactor, when a coolant pipeline ruptures, a large amount of high-energy coolant is released from the pipeline and enters the reactor containment, causing a rapid increase in pressure and temperature inside the containment, threatening the safety of the containment pressure boundary. At the same time, the coolant contains radioactive materials, and if the containment is damaged, it will cause a leak of radioactive materials, leading to a major nuclear safety accident.

[0003] To address this issue, a natural circulation cooling heat exchanger is installed inside the reactor containment. Due to the temperature difference, the water in the large water tank outside the containment circulates naturally with the heat exchanger inside the containment, carrying away the heat from inside the containment.

[0004] This technical solution has the following problems in actual operation: After a rupture accident occurs in the coolant pipeline, the temperature and pressure inside the containment rise rapidly and reach their peak, and the safety boundary is severely threatened. At this time, the natural circulation cooler is in the start-up stage. Under the huge thermal shock, its internal flow heat transfer fluctuates violently, and the flow rate is very unstable, which seriously affects the cooler's cooling capacity inside the containment in the early stage of the accident. Summary of the Invention

[0005] This invention provides a passive containment cooling system and reactor system to address the shortcomings of existing technologies, such as unstable flow rate and poor cooling capacity of natural circulation coolers in the early stages of a rupture accident in the coolant pipeline, thereby achieving efficient cooling of the containment in the early stages of a rupture accident.

[0006] This invention provides a passive containment cooling system, comprising: a storage tank, a heat exchanger, and cooling water piping; the storage tank is adapted to be disposed outside the containment for storing cooling water; the heat exchanger is disposed inside the containment, and the heat exchanger includes a first state and a second state; the cooling water piping connects the storage tank and the heat exchanger to form a heat exchange circulation loop; in the first state, the heat exchanger is filled with inorganic salt; in the second state, the heat exchanger contains a hydrated inorganic salt solution of the cooling water and the inorganic salt.

[0007] According to the present invention, a passive containment cooling system further includes: a control valve and a detection device; the control valve is disposed in the cooling water pipeline; the detection device is disposed inside the containment and connected to the control valve; when the control valve is closed, the heat exchanger is in the first state; when the control valve is open, the heat exchanger gradually changes from the first state to the second state.

[0008] According to a passive containment cooling system provided by the present invention, the cooling water pipeline includes: a first pipeline and a second pipeline; one end of the first pipeline is connected to the outlet of the storage tank, and the other end of the first pipeline is connected to the inlet of the heat exchanger; one end of the second pipeline is connected to the outlet of the heat exchanger, and the other end of the second pipeline is connected to the inlet of the storage tank; the control valve includes: a first valve body and a second valve body; the first valve body is disposed in the first pipeline, and the second valve body is disposed in the second pipeline; both the first valve body and the second valve body are connected to the detection device.

[0009] According to a passive containment cooling system provided by the present invention, the detection device includes: a temperature detector; the temperature detector is connected to the control valve.

[0010] According to a passive containment cooling system provided by the present invention, the detection device further includes: a pressure detector; the pressure detector is connected to the control valve.

[0011] According to a passive containment cooling system provided by the present invention, a plurality of heat exchangers are provided, and the plurality of heat exchangers are respectively connected to the storage tank.

[0012] According to the present invention, a passive containment cooling system is provided, wherein the inorganic salt is potassium nitrate.

[0013] According to a passive containment cooling system provided by the present invention, along the height direction of the storage tank, the inlet of the storage tank is higher than the outlet of the storage tank.

[0014] According to a passive containment cooling system provided by the present invention, the outlet of the heat exchanger is higher than the inlet of the heat exchanger along the height direction of the containment.

[0015] The present invention also provides a reactor system comprising: a containment and a passive containment cooling system as described in any of the preceding claims.

[0016] The passive containment cooling system and reactor system provided by this invention, by placing inorganic salts within the heat exchanger, allows coolant from the storage tank to flow into the heat exchanger through cooling water pipes during the initial startup phase of the passive containment cooling system. This coolant fully contacts the inorganic salts within the heat exchanger, causing a hydration reaction that absorbs a large amount of heat. The heat from the high-temperature, high-pressure working fluid within the containment is then transferred to the hydrated inorganic salt solution through the heat exchanger tube walls, achieving efficient heat absorption and storage. In the later stages of a breach accident, the passive containment cooling system smoothly transitions to a natural circulation cooling phase using the hydrated inorganic salt solution. In summary, this invention combines inorganic salt hydration heat storage with natural circulation cooling, achieving efficient cooling throughout the entire lifecycle of the passive containment cooler. This eliminates the initial cooling bottleneck of the driven passive cooler during startup and enhances the integrity of the reactor system's final safety barrier. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the passive containment cooling system provided by the present invention.

[0019] Figure label:

[0020] 1: Passive containment cooling system; 110: Storage tank; 120: Heat exchanger; 131: First piping; 132: Second piping; 141: First valve body; 142: Second valve body;

[0021] 2: Containment vessel; 3: Reactor. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0023] To address the issue of rapid pressure and temperature increases within the containment vessel during a coolant pipeline rupture accident in a pressurized water reactor, related technologies have incorporated a natural circulation cooling heat exchanger within the reactor containment vessel. Under the influence of temperature differences, water from the large water tank outside the containment vessel circulates naturally through the heat exchanger inside the containment vessel, thus removing heat from the containment vessel.

[0024] However, after the coolant pipeline ruptures, the temperature and pressure inside the containment rise rapidly and reach their peak, posing the most serious threat to the safety boundary. At this time, the natural circulation cooler is in the start-up phase. Under the huge thermal shock, the internal flow and heat transfer of the natural circulation cooler fluctuates violently, and the flow rate is very unstable, which seriously affects the cooler's cooling capacity inside the containment during the initial stage of the accident.

[0025] To address the above problems, the present invention provides a passive containment cooling system 1 and a reactor system.

[0026] The following is combined Figure 1 The passive containment cooling system 1 and reactor system of the present invention are described.

[0027] like Figure 1 As shown, the passive containment cooling system 1 provided by the present invention includes: a storage tank 110, a heat exchanger 120, and cooling water pipelines.

[0028] Storage tank 110 is adapted to be installed outside containment 2 for storing cooling water; heat exchanger 120 is installed inside containment 2, and heat exchanger 120 includes a first state and a second state; cooling water pipeline connects storage tank 110 and heat exchanger 120 to form a heat exchange loop; in the first state, heat exchanger 120 is filled with inorganic salt; in the second state, heat exchanger 120 contains a hydrated inorganic salt solution of cooling water and inorganic salt.

[0029] When the coolant pipeline inside containment 2 is working normally, the passive containment cooling system 1 is not working, the heat exchange circulation loop is disconnected, the heat exchanger 120 is disconnected from the storage tank 110, the heat exchanger 120 is in the first state, and the heat exchanger 120 is filled with inorganic salt.

[0030] When the coolant pipe of reactor 3 ruptures, the high-energy working fluid is released into containment 2, causing the temperature and pressure inside containment 2 to rise rapidly, forming a high-temperature and high-pressure working fluid.

[0031] At this time, the passive containment cooling system 1 is activated, the heat exchange circulation loop is connected, the heat exchanger 120 is connected to the storage tank 110, the heat exchanger 120 is in the second state, and the heat exchanger 120 contains flowing cooling water and a hydrated inorganic salt solution.

[0032] Understandably, inorganic salts have a high heat storage capacity. During the hydration process after inorganic salts combine with cooling water, heat can be efficiently absorbed and stored, enabling efficient cooling of the containment 2 in the early stages of a breach accident.

[0033] As time goes by, the inorganic salt in heat exchanger 120 gradually decreases until the inorganic salt in heat exchanger 120 reacts completely with the cooling water. At this time, the temperature and pressure inside containment 2 tend to stabilize. The circulating working fluid in the heat exchange loop is a hydrated inorganic salt solution. This hydrated inorganic salt solution circulates naturally in the heat exchange loop, which can meet the cooling effect inside containment 2 in the later stages of the accident.

[0034] The passive containment cooling system 1 provided by this invention, by placing inorganic salts within the heat exchanger 120, allows coolant in the storage tank 110 to flow into the heat exchanger 120 through cooling water pipes during the initial startup phase of the passive containment cooling system 1. This coolant fully contacts the inorganic salts within the heat exchanger 120, causing a hydration reaction that absorbs a large amount of heat. The heat from the high-temperature, high-pressure working fluid within the containment 2 is then transferred to the hydrated inorganic salt solution through the tube wall of the heat exchanger 120, achieving efficient heat absorption and storage. During the later stages of a breach accident, the passive containment cooling system 1 smoothly transitions to a natural circulation cooling phase for the hydrated inorganic salt solution. In summary, this invention combines inorganic salt hydration heat storage with natural circulation cooling, achieving efficient cooling throughout the containment cycle, eliminating the initial cooling bottleneck of the driven passive cooler, and enhancing the integrity of the reactor system's final safety barrier.

[0035] The storage tank 110 is a container for storing cooling water, and its capacity can be selected according to actual needs.

[0036] The cooling water can be ordinary fresh water.

[0037] Among them, inorganic salt is a heat-absorbing material, which can be any one or more of sulfate, chloride, and potassium nitrate.

[0038] In some embodiments, the inorganic salt may be potassium nitrate to meet the high temperature and high pressure conditions following a rupture in the coolant pipeline within containment 2.

[0039] Among them, heat exchanger 120 is a heat exchange device with heat exchange function, such as heat exchange tube, heat exchange plate, etc.

[0040] In some embodiments, multiple heat exchangers 120 may be provided, and the multiple heat exchangers 120 are respectively connected to the storage tank 110 to enhance the heat exchange effect.

[0041] The number and distribution of heat exchangers 120 can be set according to specific circumstances.

[0042] The heat exchanger 120 and the storage tank 110 are connected by cooling water pipes to form a heat exchange circulation loop.

[0043] Cooling water pipes are used to connect heat exchanger 120 and storage tank 110 so that the heat exchange medium can flow in the heat exchange circulation loop.

[0044] The cooling water pipeline can be any type of conduit known in the art, such as carbon steel pipe, rubber and plastic pipe, etc.

[0045] Furthermore, such as Figure 1 As shown, the cooling water pipeline includes: a first pipeline 131 and a second pipeline 132; one end of the first pipeline 131 is connected to the outlet of the storage tank 110, and the other end of the first pipeline 131 is connected to the inlet of the heat exchanger 120; one end of the second pipeline 132 is connected to the outlet of the heat exchanger 120, and the other end of the second pipeline 132 is connected to the inlet of the storage tank 110.

[0046] In some embodiments, along the height direction of the storage tank 110, the inlet of the storage tank 110 is higher than the outlet of the storage tank 110, so that the fluid can circulate naturally in the heat exchange loop by its own weight.

[0047] Furthermore, along the height direction of the containment 2, the outlet of the heat exchanger 120 is higher than the inlet of the heat exchanger 120, so that the heated hydrated inorganic salt solution can rise naturally and enter from the top of the storage tank 110 through the second pipeline 132.

[0048] In this embodiment, the density of the hydrated inorganic salt solution decreases after heating, causing it to rise naturally and enter the upper part of the storage tank 110 along the second pipe 132. The liquid at the bottom of the storage tank 110 flows naturally into the first pipe 131, thus circulating naturally and continuously carrying away the heat inside the containment vessel 2, reducing the temperature and pressure of the containment vessel 2, and ensuring its safety.

[0049] Furthermore, the passive containment cooling system 1 of the present invention also includes: a control valve and a detection device.

[0050] The control valve is located in the cooling water pipeline and is used to control the opening or closing of the cooling water pipeline; the detection device is located inside the containment 2 and is connected to the control valve. The detection device is used to control the opening or closing of the control valve.

[0051] When the control valve is closed, the heat exchanger 120 is in the first state; when the control valve is open, the heat exchanger 120 gradually changes from the first state to the second state.

[0052] When the control valve is closed, the heat exchange circulation loop is disconnected, the heat exchanger 120 is not connected to the storage tank 110, and the heat exchanger 120 is in the first state.

[0053] With the control valve open, the heat exchange circulation loop is connected, and the heat exchanger 120 is connected to the storage tank 110. The inorganic salt in the heat exchanger 120 reacts with the cooling water, and the substance in the heat exchanger 120 gradually changes from inorganic salt to hydrated inorganic salt solution. The heat exchanger 120 gradually changes from the first state to the second state, and the passive containment cooling system 1 smoothly transitions to the natural circulation cooling stage.

[0054] The detection device is used to measure the temperature and pressure inside the containment 2, and the control device controls the opening and closing of the control valve based on the measurement results of the detection device, thereby controlling the opening and closing of the passive containment cooling system 1.

[0055] In some embodiments, the detection device includes a temperature detector connected to a control valve.

[0056] If the temperature detector detects that the temperature inside containment 2 exceeds the temperature threshold, it indicates that a coolant pipeline has ruptured, and the control device will open the control valve.

[0057] In some embodiments, the detection device further includes a pressure detector; the pressure detector is connected to a control valve.

[0058] If the pressure detector detects that the pressure inside containment 2 exceeds the pressure threshold, it indicates that a coolant pipeline has ruptured, and the control device will open the control valve.

[0059] In some embodiments, the detection device includes a temperature detector and a pressure detector; if at least one of the pressure detector and the temperature detector detects that a parameter inside the containment 2 exceeds a set threshold, it indicates that a coolant pipeline rupture has occurred, and the control device controls the control valve to open. The control valve may be a safety valve known in the art.

[0060] Furthermore, the control valve includes: a first valve body 141 and a second valve body 142; the first valve body 141 is disposed in the first pipeline 131, and the second valve body 142 is disposed in the second pipeline 132; both the first valve body 141 and the second valve body 142 are connected to the detection device.

[0061] The first valve body 141 is used to control the opening and closing of the first pipeline 131, and the second valve body 142 is used to control the opening and closing of the second pipeline 132.

[0062] In this embodiment, by providing a first valve body 141 and a second valve body 142 at both ends of the heat exchanger 120, compared to providing only one valve body in the heat exchange cycle loop, the inlet and outlet of the heat exchanger 120 can be controlled to prevent the inorganic salts in the heat exchanger 120 from coming into premature contact with the cooling water.

[0063] The passive containment cooling system 1 provided by this invention utilizes inorganic salts within the heat exchanger 120. By combining the high heat storage capacity of the inorganic salt material with cooling water through hydration, efficient heat absorption and storage are achieved. This allows for efficient cooling of the containment 2 in the early stages of a breach accident, smoothly transitioning to natural circulation cooling. In summary, this invention combines inorganic salt hydration heat storage with natural circulation cooling, achieving efficient cooling throughout the entire lifecycle of the passive containment cooler. This eliminates the initial cooling bottleneck of traditional passive coolers during startup, enhancing the integrity of the reactor system's final safety barrier.

[0064] The present invention also provides a reactor system including a containment 2 and a passive containment cooling system 1 as described above.

[0065] The reactor system provided by this invention achieves efficient heat absorption and storage by incorporating inorganic salts within the heat exchanger 120 and utilizing the hydration process of the inorganic salt material with high heat storage capacity combined with cooling water. This enables efficient cooling of the containment vessel 2 in the early stages of a breach accident and a smooth transition to natural circulation cooling. In summary, this invention combines inorganic salt hydration heat storage with natural circulation cooling, achieving efficient cooling of the containment passive cooler throughout its entire lifecycle. This eliminates the initial cooling bottleneck of traditional passive coolers and enhances the integrity of the reactor system's final safety barrier.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A passive containment cooling system, characterized in that, include: Storage tank, suitable for installation outside the containment, for storing cooling water; A heat exchanger is disposed within the containment, and the heat exchanger includes a first state and a second state; Cooling water pipes connect the storage tank and the heat exchanger to form a heat exchange circulation loop; In the first state, the heat exchanger is filled with inorganic salts; in the second state, the heat exchanger contains the cooling water and the hydrated inorganic salt solution, which serves as the cooling medium for the subsequent natural circulation process. Along the height direction of the storage tank, the inlet of the storage tank is higher than the outlet of the storage tank; along the height direction of the containment vessel, the outlet of the heat exchanger is higher than the inlet of the heat exchanger.

2. The passive containment cooling system according to claim 1, characterized in that, Also includes: A control valve is installed in the cooling water pipeline; The detection device is located inside the containment and connected to the control valve; When the control valve is closed, the heat exchanger is in the first state; when the control valve is open, the heat exchanger gradually changes from the first state to the second state.

3. The passive containment cooling system according to claim 2, characterized in that, The cooling water pipeline includes: a first pipeline and a second pipeline; One end of the first pipeline is connected to the outlet of the storage tank, and the other end of the first pipeline is connected to the inlet of the heat exchanger; one end of the second pipeline is connected to the outlet of the heat exchanger, and the other end of the second pipeline is connected to the inlet of the storage tank. The control valve includes: a first valve body and a second valve body; The first valve body is disposed in the first pipeline, and the second valve body is disposed in the second pipeline; Both the first valve body and the second valve body are connected to the detection device.

4. The passive containment cooling system according to claim 2, characterized in that, The detection device includes: a temperature detector; The temperature detector is connected to the control valve.

5. The passive containment cooling system according to claim 4, characterized in that, The detection device further includes: a pressure detector; The pressure detector is connected to the control valve.

6. The passive containment cooling system according to claim 1, characterized in that, Multiple heat exchangers are provided, and each heat exchanger is connected to the storage tank.

7. The passive containment cooling system according to claim 1, characterized in that, The inorganic salt is potassium nitrate.

8. A reactor system, characterized in that, Includes the containment and the passive containment cooling system as described in any one of claims 1 to 7.

Images