CN115331849A - Passive residual heat removal system and method for nuclear reactor - Google Patents
Passive residual heat removal system and method for nuclear reactor Download PDFInfo
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- G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
- G21C—NUCLEAR REACTORS
- G21C15/00—Cooling arrangements within the pressure vessel containing the core; Selection of specific coolants
- G21C15/18—Emergency cooling arrangements; Removing shut-down heat
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
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Abstract
The invention discloses a passive residual heat removal system and a passive residual heat removal method for a nuclear reactor, wherein the system comprises a reactor system, the hot end of the reactor system is connected with an inlet pipeline, the inlet pipeline is connected with a heat exchanger through a heat exchanger inlet header, and an isolation valve is arranged on the inlet pipeline between the reactor system and the heat exchanger inlet header; the heat exchangers are arranged in multiple stages, the multiple stages of heat exchangers are connected in series, and a heat exchanger intermediate header is arranged between every two adjacent stages of heat exchangers; the outlet of the heat exchanger is connected with an outlet pipeline, and a heat exchanger outlet header and an isolation valve are arranged on the outlet pipeline; the passive residual heat removal system for the nuclear reactor can meet different requirements on the heat carrying capacity of the residual heat removal system under different accidents, avoids too large or too small heat carrying capacity through the design of the multistage heat exchanger, and reduces the adverse effect on the nuclear reactor system caused by the false start of the passive residual heat removal system.
Description
Technical Field
The invention relates to the technical field of nuclear reactor safety, in particular to a passive residual heat removal system and method for a nuclear reactor.
Background
Under normal operation conditions, the heat of the reactor core of the nuclear reactor is led out to a steam turbine through a main heat exchanger such as a steam generator and the like so as to generate electric power, or is led out to a heat supply/steam supply system to generate heat energy or steam. After the nuclear reactor has an accident, the main heat exchangers such as the steam generator and the like are not available, and a waste heat discharge system is required to be configured to take out the waste heat of the reactor core in time, so that the accident is further deteriorated into a serious accident, and the harm of a large amount of radioactive release is caused.
In the conventional second-generation nuclear power station, an active waste heat discharge system is generally adopted to take out the waste heat of the reactor core, the active system depends on external power and needs to be provided with supporting systems such as equipment cooling water and the like, once the external power or the supporting systems are lost, the active waste heat discharge system cannot execute the functions of the active waste heat discharge system, and the waste heat of the reactor core cannot be taken out, so that the safety of the nuclear reactor is threatened.
In some third-generation nuclear power plants, passive residual heat removal systems are adopted, the function execution of the passive residual heat removal systems does not depend on external power, does not need supporting systems such as equipment cooling water and the like, and takes out core heat by means of natural physical laws (density difference, natural circulation, heat conduction and the like). The failure probability of the passive residual heat removal system is far lower than that of the active residual heat removal system, and the safety of the nuclear reactor is improved.
The inventors have found that under different accidents (e.g. a LOCA accident and a non-LOCA accident), the thermal capacity of the passive waste heat removal system may have different requirements. The existing passive residual heat removal system cannot give reasonable consideration to different accidents. The heat carrying capacity of the waste heat discharge system is too small, so that excessive heat of the reactor core is accumulated, and the reactor core is possibly melted; if the thermal energy is too large, the main system of the nuclear reactor is overcooled, thermal shock is caused, the fatigue of key components and the integrity of a pressure bearing structure are threatened, and more serious accident consequences are caused when the passive residual heat removal system is started by mistake.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides a passive residual heat removal system and a passive residual heat removal method for a nuclear reactor, which can meet different requirements on the heat carrying capacity of the residual heat removal system under different accidents, avoid too large or too small heat carrying capacity, and reduce the adverse effect of the false start of the passive residual heat removal system on the nuclear reactor system.
The technical scheme of the invention is as follows:
in a first aspect of the invention, a passive residual heat removal system for a nuclear reactor comprises a reactor system, wherein a hot end of the reactor system is connected with an inlet pipeline, the inlet pipeline is connected with a heat exchanger through a heat exchanger inlet header, and an isolating valve is arranged on the inlet pipeline between the reactor system and the heat exchanger inlet header;
the heat exchangers are arranged in multiple stages, the multiple stages of heat exchangers are connected in series, and a heat exchanger intermediate header is arranged between every two adjacent stages of heat exchangers;
the side outlet of the heat exchanger intermediate header and the outlet of the last stage of heat exchanger are both connected with an outlet pipeline, the outlet pipeline is connected with the cold end of the reactor system through the heat exchanger outlet header, and an isolation valve is arranged on the outlet pipeline between the reactor system and the heat exchanger outlet header.
In some embodiments of the invention, the reactor system is a nuclear reactor primary side system or a nuclear reactor secondary side system.
In some embodiments of the invention, the multi-stage heat exchanger is placed in a hot-trap water tank and is arranged in stages from top to bottom.
In some embodiments of the invention, the hot-trap water tank is a water tank with a certain water content or a natural cooling water source, and the water level of the hot-trap water tank is higher than that of the first-stage heat exchanger.
In some embodiments of the invention, the hot-trap water tank is used in conjunction with a containment vessel, a reflux collection tank, and a reflux line; the backflow collecting tank is connected with the containment, one end of the backflow pipeline is connected with the bottom of the backflow collecting tank, and the other end of the backflow pipeline is located above the hot-trap water tank.
In some embodiments of the present invention, the heat exchanger includes a plurality of sets of basic heat exchange modules, and the basic heat exchange modules have two forms, namely straight tube type basic heat exchange modules or bent tube type basic heat exchange modules.
In some embodiments of the invention, each group of base modules comprises a group of straight tube heat exchange tube bundles or a group of bent tube heat exchange tube bundles, and end tube plates are arranged at two ends of the straight tube heat exchange tube bundles or the bent tube heat exchange tube bundles; furthermore, the arrangement mode of the straight pipe heat exchange tube bundle or the bent pipe heat exchange tube bundle is in a fork row or a straight row.
In some embodiments of the present invention, the heat exchanger intermediate header includes a main connection pipe and side connection pipes, the side connection pipes are disposed at sides of the main connection pipe, end pipe plates are disposed at upper and lower sides of the main connection pipe, and pipe flanges are mounted on the side connection pipes.
In some embodiments of the invention, the heat exchanger inlet header and the heat exchanger outlet header are of the same structure and comprise an inlet ellipsoidal head, an outlet ellipsoidal head and a cylindrical barrel, wherein the outlet ellipsoidal head is connected with a plurality of pipelines which are centrosymmetric along the central axis of the outlet ellipsoidal head.
In a second aspect of the invention, a passive residual heat removal method for a nuclear reactor is provided, wherein in normal operation of the nuclear reactor, an inlet isolation valve of a passive residual heat removal system is in an open state, and an outlet isolation valve is in a closed state;
when an accident occurs, opening an outlet isolation valve in the passive residual heat removal system to form a circulating loop of communicated fluid, carrying heat generated by the reactor system by the fluid, transferring the heat to a heat trap water tank through a multistage heat exchanger, and returning the fluid after transferring the heat to the reactor system to form circulation;
further, the number of stages of the heat exchanger is selected to be used according to different accidents or different stages of accidents.
One or more technical schemes of the invention have the following beneficial effects:
(1) The passive residual heat removal system for the nuclear reactor adopts a passive safety design concept, does not depend on external power (such as a power supply, a steam source and the like), does not need a support system (such as equipment cooling water, a power supply and the like), has extremely low failure probability, and improves the safety of the nuclear reactor; the driving fluid forms natural circulation in the reactor system and the passive residual heat removal system by means of natural physical laws (density difference, natural circulation and the like) to carry out the residual heat of the reactor core.
(2) The passive residual heat removal system for the nuclear reactor can meet different requirements on the heat carrying capacity of the residual heat removal system under different accidents, avoids too large or too small heat carrying capacity through the design of the multistage heat exchanger, and reduces the adverse effect on the nuclear reactor system caused by the false start of the passive residual heat removal system.
(3) The invention can expand the heat exchanger of the passive waste heat system according to the requirements of nuclear reactors with different power levels, adopts modular design and is flexible to install; the reactor core waste heat recovery device can meet the requirement for discharging the reactor core waste heat after different accidents, and has the characteristics of strong expandability, flexible installation, suitability for nuclear reactors with different power levels and the like.
Drawings
FIG. 1 is a schematic structural diagram of a passive residual heat removal system for a reactor;
fig. 2 is a schematic view of a basic heat exchange module of the present invention, wherein fig. 2 (a) is a schematic view of a straight tube type basic heat exchange module, fig. 2 (b) is a schematic view of a bent tube type basic heat exchange module, fig. 2 (c) is a schematic view of a row tube bundle, fig. 2 (d) is a schematic view of a cross-row tube bundle, fig. 2 (e) is a schematic view of a circular flange, and fig. 2 (f) is a schematic view of a hexagonal flange;
FIG. 3 is a schematic diagram of the parallel arrangement of the end tube sheets of multiple basic heat exchange modules of the present invention;
FIG. 4 is a schematic structural view of an intermediate header of the heat exchanger of the present invention;
FIG. 5 is a schematic view of the heat exchanger inlet and outlet headers of the present invention;
fig. 6 is a schematic diagram of a connection mode of the basic heat exchange modules of the present invention, wherein fig. 6 (a) is a schematic diagram of a straight tube type basic heat exchange module connected in series, fig. 6 (b) is a schematic diagram of a straight tube type basic heat exchange module connected in parallel, fig. 6 (c) is a schematic diagram of a straight tube type basic heat exchange module connected in series with a bent tube type basic heat exchange module, and fig. 6 (d) is a schematic diagram of a straight tube type basic heat exchange module connected in series with a bent tube type basic heat exchange module and then connected in parallel;
fig. 7 is a schematic configuration diagram of a passive residual heat removal system for a reactor provided with a multistage heat exchanger.
Detailed Description
It is to be understood that the following detailed description is exemplary and is intended to provide further explanation of the invention as claimed. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.
It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an", and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.
Example 1
In an exemplary embodiment of the present invention, a passive residual heat removal system for a nuclear reactor is provided, as shown in fig. 1, including a reactor system 10, a hot end (e.g., a primary side heat pipe section, a secondary side outlet) of the reactor system 10 is connected to an inlet pipe 11, the inlet pipe 11 is connected to a first stage heat exchanger 20 through a heat exchanger inlet header 12, and a first isolation valve 1 is disposed on the inlet pipe between the reactor system 10 and the heat exchanger inlet header 12. The heat exchangers are arranged in two stages, a first stage heat exchanger 20 and a second stage heat exchanger 30 are connected in series, and a heat exchanger intermediate header 23 is arranged between the two stages of heat exchangers; the side outlet of the intermediate heat exchanger header 23 is connected to the first outlet conduit 21, and the outlet of the second stage heat exchanger 30 is connected to the outlet conduit 31; a first heat exchanger outlet header 22 is connected to the cold side (e.g., primary side cold leg, secondary side inlet) of the reactor system 10 by a first outlet conduit 21, and a second heat exchanger outlet header 32 is connected to the cold side of the reactor system 10 by a second outlet conduit 31; a first outlet isolation valve 2 is provided on the first outlet conduit 21 and a second outlet isolation valve 3 is provided on the second conduit 31.
The reactor system 10 may be a nuclear reactor primary side system or a nuclear reactor secondary side system, such as a steam generator.
The heat exchangers are placed in the hot-trap water tank 50 and are sequentially arranged step by step from top to bottom, the hot-trap water tank 50 can be a water tank with a certain water capacity, and can also be a natural cooling water source such as rivers, lakes, seas and the like, and the water surface of the hot-trap water tank 50 is higher than the first-stage heat exchanger 20 and the second-stage heat exchanger 30.
The hot-trap water tank 50 is matched with a containment vessel 60, a backflow collecting tank 51 and a backflow pipeline 52 for use; the return collection tank 51 is connected with the containment vessel 60, one end of the return pipeline 52 is connected with the bottom of the return collection tank 51, and the other end is positioned above the hot-trap water tank 50.
The first-stage heat exchanger 20, the heat exchanger intermediate header 23 and the second-stage heat exchanger 30 are fixedly arranged in the hot-trap water tank 50; the first and second stage heat exchangers 20 and 30 are each positioned at a center elevation higher than a center elevation of the hot zone of the reactor system 10. According to different application scenarios, when the reactor system 10 is a nuclear reactor primary side system, the reactor system 10 hot zone refers to a reactor core; when the reactor system 10 is a nuclear reactor secondary side system, the reactor system 10 hot zone refers to a heat exchange tube bundle of a secondary side heat exchanger.
The first stage heat exchanger 20 and the second stage heat exchanger 30 are in the form of tube bundles arranged in either a cross-row or a row. The first-stage heat exchanger 20 and the second-stage heat exchanger 30 are formed by combining a plurality of groups of basic heat exchange modules according to requirements. The first-stage heat exchanger 20, the second-stage heat exchanger 30 and the heat exchanger intermediate header 23 are connected in series to form a passage, and multiple paths may be connected in parallel.
The basic heat exchange module has two forms, as shown in fig. 2 (a) and 2 (b), and includes a straight tube type basic heat exchange module 100 and a bent tube type basic heat exchange module 200. Each base module is comprised of two end tube sheets 110, a set of straight tube heat exchanger bundles 120, or a set of bent tube heat exchanger bundles 130. The straight tube heat exchange tube bundle 120 and the bent tube heat exchange tube bundle 130 are formed by parallel arrangement of metal round tubes 101 with certain thickness, the inner diameter of the round tubes is between 5mm and 25mm, the thickness of the tube wall is between 0.5 mm and 5mm, or the specification meeting the national standard is adopted; the length of the metal round tube 101 can be customized according to needs; the material of the metal round tube 101 may be stainless steel, titanium alloy, aluminum alloy, or the like. The metal round pipe 101 is in a form that the straight pipe type basic heat exchange module 100 is a straight pipe, and the bent pipe type basic heat exchange module 200 is a round pipe with a 90-degree bend in the middle of the pipe; each basic module only adopts one type of round pipe, namely, the round pipes are straight pipes or round pipes containing 90-degree bent pipes. The number of the metal round tubes 101 composing the straight tube heat exchange tube bundle 120 and the bent tube heat exchange tube bundle 130 can be customized as required. As shown in fig. 2 (c) and 2 (d), the arrangement of the metal round tubes 101 of the straight tube heat exchange tube bundle 120 and the bent tube heat exchange tube bundle 130 may be in a fork arrangement or a straight arrangement; the center distance between the metal round pipes 101 is 1.1 to 2 times of the outer diameter of the metal round pipes 101; the center-to-center distance between the metal round tubes 101 is kept constant in the longitudinal direction.
Two end tube plates 110 of the straight tube type basic heat exchange module 100 are respectively connected with two ends of a straight tube heat exchange tube bundle 120 in a welding mode. The two end tube plates 110 of the elbow type basic heat exchange module 200 are respectively connected with the two ends of the elbow type heat exchange tube bundle 130 by welding.
Each end tube plate 110 is provided with openings 103 corresponding to the number and size of the metal round tubes 101, and both ends of each metal round tube 101 are connected with the openings of the two end tube plates 110 respectively. As shown in fig. 2 (e) and 2 (f), the end tube sheet 110 may employ a circular flange, complying with national standards specifications to reduce manufacturing costs; hexagonal flanges may also be used; as shown in fig. 3, when multiple sets of end tube sheets are arranged in parallel, the tube bundle can be arranged more closely, and the space required for installation is substantially reduced. The basic heat exchange module can be modularly prefabricated in a manufacturing factory and then transported to a nuclear reactor site for assembly, so that construction and installation are facilitated.
As shown in fig. 4, the intermediate header of the heat exchanger includes a main connection pipe 140 and side connection pipes 150, the side connection pipes 150 are disposed at the sides of the main connection pipe 140, end pipe plates 110 are disposed at the upper and lower sides of the main connection pipe 140, and pipe flanges 111 are mounted on the side connection pipes; the main connecting pipe 140 is in the form of a straight circular pipe, and the inner diameter of the pipe is not less than the diameter of the maximum circumscribed circle of the tube bundle open area of the end tube plate 110, so as to ensure that all the fluid in the tube bundle connected with the end tube plate 110 can enter the main connecting pipe 140; the length of the main connection pipe 140 is not greater than that of a group of basic heat exchange modules; the main connection pipe 140 is connected at both ends thereof to the two end tube plates 110, respectively. The side connection pipe 150 is in the form of a circular pipe having an inner diameter not greater than that of the main connection pipe 140; the side connection pipe 150 may be composed of a plurality of elbows and straight pipe sections, the length and orientation of which are determined by the installation requirements, so that the heat exchanger intermediate header 23 can be connected to the inlet of the first heat exchanger intermediate outlet header 22; the side connection pipe 150 has one end connected to a side of the middle of the main connection pipe 140 and the other end connected to the pipe flange 111.
As shown in fig. 5, the heat exchanger inlet header 12, the first heat exchanger outlet header 22, and the second heat exchanger outlet header 32 have the same structure, and are composed of an inlet ellipsoidal head 121, an outlet ellipsoidal head 123, and a cylindrical barrel 122. The cylindrical barrel 122 has a diameter not smaller than the diameter of the inlet duct 11, the first outlet duct 21 or the second outlet duct 31. The inlet ellipsoidal head 121 is connected to one end of the inlet pipe 11, the first outlet pipe 21, or the second outlet pipe 31; the outlet ellipsoidal head 123 is connected to the first stage heat exchanger 20, the second stage heat exchanger 30, or the tubes of the intermediate header 23 of the heat exchanger. When the first-stage heat exchanger 20 and the second-stage heat exchanger 30 are composed of a plurality of groups of basic heat exchange modules connected in parallel, a plurality of pipelines which are centrosymmetric along the central axis of the outlet ellipsoid head 123 can be connected.
As shown in fig. 6, according to the requirements of installation convenience and maintenance convenience, the first stage heat exchanger 20 and the second stage heat exchanger 30 may adopt basic heat exchange modules of different combination modes, as shown in fig. 6 (a) -6 (d), including but not limited to connecting multiple sets of straight tube type basic heat exchange modules 100 in series, connecting multiple sets of straight tube type basic heat exchange modules 100 in parallel, connecting the straight tube type basic heat exchange modules 100 in series with the bent tube type basic heat exchange modules 200 in series, and then connecting multiple sets in parallel.
Depending on the accident to be dealt with by each nuclear reactor, a further heat exchanger may be added to the first-stage heat exchanger 20 and the second-stage heat exchanger 30. As shown in fig. 7, a third stage heat exchanger 40 may be provided, and a second heat exchanger intermediate header 33 may be provided between the second stage heat exchanger 30 and the third heat exchanger 40, specifically, an outlet of the second stage heat exchanger 30 is connected to an inlet of the second heat exchanger intermediate header 33; the outlet of the second heat exchanger intermediate header 33 is connected to the inlet of the third stage heat exchanger 40; the outlet of the second heat exchanger intermediate header 33 is connected to the inlet of the third heat exchanger outlet header 32; the outlet of the third stage heat exchanger 40 is connected to the inlet of a third heat exchanger outlet header 42. So as to more flexibly meet the requirements of various accidents on waste heat discharge.
The operation principle of the passive residual heat removal system for the nuclear reactor of the embodiment is as follows:
when the nuclear reactor normally operates, the inlet isolating valve of the passive residual heat removal system is in an open state, and the outlet isolating valve of the passive residual heat removal system is in a closed state, and the setting mode has the following advantages: (1) The inlet isolation valve of the passive residual heat removal system is opened, so that the temperature of fluid in the inlet pipe is higher than that of the fluid in the outlet pipe before the passive residual heat removal system is put into operation, and the initial natural circulation is strengthened during putting in; (2) The inlet isolation valve is opened, and the outlet isolation valve is closed, so that when the passive residual heat removal system is put into operation, the operation can be carried out only by ensuring that the outlet isolation valve can be opened, and the inlet and outlet isolation valves are not required to be opened, thereby eliminating the risk of failure in the operation of the passive residual heat removal system caused by failure of the inlet isolation valve; (3) The inlet isolation valve is opened, the outlet isolation valve is closed, fluid from the inlet isolation valve is isolated in the main flow direction, and no large-scale fluid flows in, but if the inlet isolation valve and the outlet isolation valve are both closed, the fluid in the passive surplus heat transfer pipe is in a water body closed state, and the structural boundary formed by the isolation valve and the heat transfer pipe is threatened by heat conduction and heat leakage, for example, the isolation valve is leaked.
Under the condition of accidents, the main heat exchangers such as the steam generator are unavailable, the heat of the reactor core cannot be led out through the main heat exchangers such as the steam generator, in order to prevent the accidents from further worsening into serious accidents, the passive waste heat discharge system can be started through the passive waste heat discharge system trigger signals (such as high temperature at the outlet of the reactor core, low water level of the steam generator, low pressure of a pressure stabilizer and the like), and the outlet isolation valve in the middle of the passive waste heat discharge system is opened, so that a communicated fluid circulation loop is formed between the reactor system and each stage of heat exchanger.
The heat generated in the reactor system is carried by the fluid, the fluid enters the heat exchangers of all stages in sequence through the connecting pipelines, the heat exchangers transfer the heat to the hot trap water tank, and then the fluid returns to the reactor system through the connecting pipelines. In the whole process, the fluid forms natural circulation under the driving of density difference of the fluid in the reactor system and the fluid in each stage of heat exchanger.
The water in the hot-trap water tank is continuously heated until the water is saturated and evaporated, and the steam is cooled by the inner wall surface of the containment and condensed into water, collected by the backflow collecting tank and returned to the hot-trap water tank through the backflow pipeline to realize long-term circulation. The heat of the inner wall surface of the containment is brought to the outer wall surface through heat conduction, and is finally discharged into the atmospheric environment through modes such as convection heat exchange and the like. In the accident process, along with the reduction of the continuous heat of the system and the decay heat of the reactor core, the heat capacity of the system is finally matched with the decay heat of the reactor core, and the power plant is not likely to have more serious accident conditions.
In some accident conditions (e.g., a LOCA accident) or during different phases of the accident, if more waste heat removal capacity is required, the number of open outlet isolation valves may be increased based on a trigger signal (e.g., a pressurizer low pressure), which allows fluid from the reactor system to enter the multi-stage heat exchanger, transferring heat to the hot-trap water tank. This results in a lower enthalpy of the fluid returning to the reactor system. The fluid is also driven by the density difference to form natural circulation in the whole process.
On the other hand, if when the nuclear reactor normally operates, the inlet isolation valve of the passive residual heat removal system is mistakenly opened due to misoperation or system abnormity, although fluid of the reactor system can enter the first-stage heat exchanger and is moved out of the energy of the reactor system, and further the accidental temperature and pressure reduction of the reactor system is caused, because the heat exchange capacity of the first-stage heat exchanger is relatively small, compared with the existing passive residual heat removal system, the adverse effect on the nuclear reactor system is relatively small.
Example 2
In a typical embodiment of the invention, a passive residual heat removal method for a nuclear reactor is provided,
when the nuclear reactor normally operates, the passive residual heat removal system inlet isolation valve is in an open state, and the passive residual heat removal system outlet isolation valve is in a closed state;
when an accident occurs, opening an outlet isolation valve in the passive residual heat removal system to form a circulating loop of communicated fluid, carrying heat generated by the reactor system by the fluid, transferring the heat to a heat trap water tank through a multistage heat exchanger, and returning the fluid after transferring the heat to the reactor system to form circulation;
furthermore, the number of stages of the heat exchanger is selected according to different accidents or different stages of the accidents.
The embodiments described above are intended to illustrate the technical solutions of the present invention in detail, and it should be understood that the above-mentioned embodiments are only specific embodiments of the present invention, and are not intended to limit the present invention, and any modification, supplement or similar substitution made within the scope of the principles of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. A passive residual heat removal system for a nuclear reactor is characterized by comprising a reactor system, wherein the hot end of the reactor system is connected with an inlet pipeline, the inlet pipeline is connected with a heat exchanger through a heat exchanger inlet header, and an isolating valve is arranged on the inlet pipeline between the reactor system and the heat exchanger inlet header;
the heat exchangers are arranged in multiple stages, the multiple stages of heat exchangers are connected in series, and a heat exchanger intermediate header is arranged between every two adjacent stages of heat exchangers;
the side outlet of the heat exchanger intermediate header and the outlet of the last stage of heat exchanger are both connected with an outlet pipeline, the outlet pipeline is connected with the cold end of the reactor system through the heat exchanger outlet header, and an isolation valve is arranged on the outlet pipeline between the reactor system and the heat exchanger outlet header.
2. The passive residual heat removal system for a nuclear reactor of claim 1, wherein the reactor system is a nuclear reactor primary side system or a nuclear reactor secondary side system.
3. The passive residual heat removal system for a nuclear reactor according to claim 1, wherein the multi-stage heat exchangers are placed in the hot-trap water tank and are arranged in a cascade from top to bottom.
4. The passive residual heat removal system for a nuclear reactor according to claim 3, wherein the hot-trap water tank is a water tank with a certain water content or a natural cooling water source, and the water level of the hot-trap water tank is higher than that of the first-stage heat exchanger.
5. The passive residual heat removal system for a nuclear reactor according to claim 4, wherein the hot trap water tank is used in combination with the containment, the return collection tank, and the return line; the backflow collecting tank is connected with the containment, one end of the backflow pipeline is connected with the bottom of the backflow collecting tank, and the other end of the backflow pipeline is located above the hot-trap water tank.
6. The passive residual heat removal system for a nuclear reactor according to claim 1, wherein the heat exchanger comprises a plurality of groups of basic heat exchange modules, and the basic heat exchange modules have two forms, namely a straight tube type basic heat exchange module or a bent tube type basic heat exchange module.
7. The passive residual heat removal system for a nuclear reactor according to claim 6, wherein each group of base modules comprises a group of straight tube heat exchange tube bundles or a group of bent tube heat exchange tube bundles, and end tube plates are arranged at two ends of each straight tube heat exchange tube bundle or each bent tube heat exchange tube bundle; furthermore, the arrangement mode of the straight pipe heat exchange tube bundle or the bent pipe heat exchange tube bundle is in a fork row or a straight row.
8. The passive residual heat removal system for a nuclear reactor according to claim 1, wherein the heat exchanger intermediate header includes a main connection pipe and side connection pipes, the side connection pipes are disposed at sides of the main connection pipe, end pipe plates are disposed at upper and lower sides of the main connection pipe, and pipe flanges are mounted on the side connection pipes.
9. The passive residual heat removal system for a nuclear reactor according to claim 1, wherein the heat exchanger inlet header and the heat exchanger outlet header have the same structure and comprise an inlet ellipsoidal head, an outlet ellipsoidal head and a cylindrical barrel, and the outlet ellipsoidal head is connected with a plurality of pipelines which are centrosymmetric along the central axis of the outlet ellipsoidal head.
10. A passive residual heat removal method for a nuclear reactor using the passive residual heat removal system for a nuclear reactor according to any one of claims 1 to 9,
when a nuclear reactor normally operates, an inlet isolation valve of the passive residual heat removal system is in an open state, and an outlet isolation valve is in a closed state;
when an accident occurs, opening an outlet isolation valve in the passive residual heat removal system to form a circulating loop of communicated fluid, carrying heat generated by the reactor system by the fluid, transferring the heat to a heat trap water tank through a multistage heat exchanger, and returning the fluid after transferring the heat to the reactor system to form circulation;
further, the number of stages of the heat exchanger is selected to be used according to different accidents or different stages of accidents.
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| CN202211115574.4A CN115331849A (en) | 2022-09-14 | 2022-09-14 | Passive residual heat removal system and method for nuclear reactor |
| PCT/CN2023/096007 WO2024055628A1 (en) | 2022-09-14 | 2023-05-24 | Passive residual heat removal system and method for nuclear reactor |
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| CN202211115574.4A CN115331849A (en) | 2022-09-14 | 2022-09-14 | Passive residual heat removal system and method for nuclear reactor |
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| WO (1) | WO2024055628A1 (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| WO2024055628A1 (en) * | 2022-09-14 | 2024-03-21 | 上海核工程研究设计院股份有限公司 | Passive residual heat removal system and method for nuclear reactor |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4753771A (en) * | 1986-02-07 | 1988-06-28 | Westinghouse Electric Corp. | Passive safety system for a pressurized water nuclear reactor |
| US5255296A (en) * | 1992-06-24 | 1993-10-19 | Westinghouse Electric Corp. | Collecting and recirculating condensate in a nuclear reactor containment |
| CN202018219U (en) * | 2010-11-26 | 2011-10-26 | 李颖 | Multistage combined heat exchange device |
| US9275761B2 (en) * | 2012-06-13 | 2016-03-01 | Westinghouse Electric Company Llc | Small modular reactor safety systems |
| CN106653106A (en) * | 2017-01-19 | 2017-05-10 | 华南理工大学 | Nuclear power station spent fuel pool multistage long-distance passive heat pipe cooling system |
| CN110207523B (en) * | 2019-05-08 | 2022-12-09 | 中国核电工程有限公司 | Multistage cooling system of nuclear power plant equipment cooling water |
| CN110265158B (en) * | 2019-06-24 | 2024-09-24 | 上海核工程研究设计院股份有限公司 | Multi-power-scale integrated reactor and application method thereof |
| CN110570957B (en) * | 2019-09-06 | 2024-04-12 | 长江勘测规划设计研究有限责任公司 | Multistage reciprocating passive cooling system of underground nuclear power station |
| CN111430050B (en) * | 2020-04-24 | 2024-06-18 | 上海核工程研究设计院股份有限公司 | Passive residual heat removal system for secondary side of reactor and use method |
| CN115331849A (en) * | 2022-09-14 | 2022-11-11 | 上海核工程研究设计院有限公司 | Passive residual heat removal system and method for nuclear reactor |
-
2022
- 2022-09-14 CN CN202211115574.4A patent/CN115331849A/en not_active Withdrawn
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| Publication number | Priority date | Publication date | Assignee | Title |
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| WO2024055628A1 (en) * | 2022-09-14 | 2024-03-21 | 上海核工程研究设计院股份有限公司 | Passive residual heat removal system and method for nuclear reactor |
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| WO2024055628A1 (en) | 2024-03-21 |
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