CN116189933A

CN116189933A - Submerged containment vessel with active water cooled heat sink

Info

Publication number: CN116189933A
Application number: CN202310055133.8A
Authority: CN
Inventors: 赵梓辰; 陈鹏; 郭超; 李亚冰; 展德奎; 夏少雄
Original assignee: China General Nuclear Power Corp; China Nuclear Power Technology Research Institute Co Ltd; CGN Power Co Ltd
Current assignee: China General Nuclear Power Corp; China Nuclear Power Technology Research Institute Co Ltd; CGN Power Co Ltd
Priority date: 2023-02-03
Filing date: 2023-02-03
Publication date: 2023-05-30

Abstract

The invention discloses a submerged containment vessel with an active water-cooling heat trap, which comprises a vessel body and a water-cooling heat trap; the shell body is submerged, the inside of the shell body comprises a cavity and a stacking pit which are communicated, and the stacking pit is closer to the bottom of the shell body than the cavity; the water-cooling heat trap comprises an input channel, an output channel, a circulating pump, an external water pool and a heat exchanger, wherein two opposite ends of the heat exchanger are respectively connected with the input channel and the output channel; the input channel and the output channel are respectively connected to the shell body, the input channel is communicated with the cavity, the output channel is communicated with the stacking pit, and a closed loop is formed between the shell body and the water-cooling heat trap; the circulating pump is arranged in the input channel and/or the output channel so as to drive the water vapor in the closed loop to circulate. The low-power consumption circulating pump drives the water vapor in the loop to circulate, and has the advantages of small electricity demand, strong heat sink capacity and good heat exchange effect; in addition, the design of the submerged shell and the external pool is adopted, so that the load on the containment structure is small and the anti-seismic requirement is low.

Description

Submerged containment vessel with active water cooled heat sink

Technical Field

The invention relates to the field of safety systems of nuclear reactors, in particular to a submerged containment with an active water-cooled heat sink.

Background

The containment is the last physical barrier to avoid radioactive substances from leaking out when an accident occurs in the nuclear power station, and when the accident occurs, reactor decay heat and a large amount of high-temperature steam are gradually accumulated in the containment, so that the risk of overtemperature and overpressure failure of the containment can occur.

The containment is only a safety barrier with certain pressure resistance and does not have a final heat sink function, and in the prior art, three modes of active spraying, steel shell liquid film cooling and heat pipe cooling are generally adopted to finally discharge heat into the atmosphere.

Wherein, the mode of active spraying requires overcoming back pressure and high-position water head in the shell, and the electricity requirement is large; the liquid film cooling mode of the steel shell requires a high-level water tank and has insufficient heat sink capacity; the heat pipe type cooling mode also needs a high-level water tank, the containment structure has high load and high anti-seismic requirement, in addition, the heat sink capacity is limited, the heat pipe has large heat exchange area requirement, the heat exchange effect is poor, and the overall economy is poor.

Disclosure of Invention

The invention aims to solve the technical problem of providing a submerged containment vessel with an active water-cooling heat sink.

The technical scheme adopted for solving the technical problems is as follows:

providing a submerged containment vessel with an active water-cooled heat sink, comprising a vessel body and a water-cooled heat sink; the bottom datum plane of the shell body is lower than the ground, the shell body comprises a cavity and a stacking pit which are communicated, and the stacking pit is closer to the bottom of the shell body than the cavity; the water-cooling heat trap comprises an input channel, an output channel, a circulating pump, a water pool arranged outside the shell body and a heat exchanger arranged in the water pool, wherein two opposite ends of the heat exchanger are respectively connected with the input channel and the output channel; the input channel and the output channel are respectively connected to the shell body, the input channel is communicated with the cavity, the output channel is communicated with the stacking pit, and a closed loop is formed between the shell body and the water-cooling heat trap; the circulating pump is arranged in the input channel and/or the output channel so as to drive the water vapor in the closed loop to circulate.

In some embodiments, the heat exchanger includes oppositely disposed inlet and outlet ends, the inlet end being higher than the outlet end; the inlet end is connected with the input channel, and the outlet end is connected with the output channel.

In some embodiments, the bottom elevation of the heat exchanger is higher than the top of the wall of the pit.

In some embodiments, the height of the inlet end of the output channel is greater than or equal to the height of the outlet end of the output channel.

In some embodiments, the water basin is disposed at a periphery of the housing body, and the heat exchanger is disposed within the water basin and submerged in a body of water of the water basin.

In some embodiments, the pool is above ground or below ground.

In some embodiments, isolation valves are respectively arranged on the input channel and the output channel to control the conduction of the closed loop.

In some embodiments, a pressure vessel is disposed within the pit and an interior of the pressure vessel is provided with a core fuel zone, a wall top of the pit being higher than a top elevation of the core fuel zone.

In some embodiments, the bottom elevation of the heat exchanger is higher than the top elevation of the core fuel zone.

In some embodiments, the pressure vessel and the wall of the pit form a gap, the output channel communicates with the gap, and an in-pile melt retention system is formed between the pressure vessel and the pit.

The implementation of the invention has the following beneficial effects: the invention adopts the design of the water-cooling heat trap, the water-cooling heat trap and the shell body form a closed circulation loop, and the water vapor circulation is completed in the loop under the drive of the low-power consumption circulation pump, so that the invention has the advantages of small electricity consumption requirement, strong heat trap capacity and good heat exchange effect; in addition, the design of the submerged shell and the external water tank is adopted, so that the problems of high load and high anti-seismic requirement of the high-level water tank on the containment structure are solved.

Drawings

The invention will be further described with reference to the accompanying drawings and examples, in which:

FIG. 1 is a schematic structural diagram of a nuclear island arrangement of one embodiment of the present invention;

fig. 2 is a schematic structural diagram of a nuclear island arrangement of one embodiment of the present invention.

Detailed Description

For a clearer understanding of technical features, objects and effects of the present invention, a detailed description of embodiments of the present invention will be made with reference to the accompanying drawings. In the following description, it should be understood that the directions or positional relationships indicated by "front", "rear", "upper", "lower", "left", "right", "longitudinal", "transverse", "vertical", "horizontal", "top", "bottom", "inner", "outer", "head", "tail", etc. are configured and operated in specific directions based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present invention, and do not indicate that the apparatus or element to be referred to must have specific directions, and thus should not be construed as limiting the present invention.

It should also be noted that unless explicitly stated or limited otherwise, terms such as "mounted," "connected," "secured," "disposed," and the like are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. When an element is referred to as being "on" or "under" another element, it can be "directly" or "indirectly" on the other element or one or more intervening elements may also be present. The terms "first," "second," "third," and the like are used merely for convenience in describing the present invention and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated, whereby features defining "first," "second," "third," etc. may explicitly or implicitly include one or more such features. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

In the following description, for purposes of explanation and not limitation, specific details are set forth such as the particular system architecture, techniques, etc., in order to provide a thorough understanding of the embodiments of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

Fig. 1 illustrates a nuclear island arrangement and primary equipment in some embodiments of the invention, including a containment vessel 1, a pressure vessel 2, and a core fuel zone 3. The containment vessel 1 is used to prevent the escape of radioactive materials after an accident. The pressure vessel 2 is arranged at the bottom of the containment vessel 1 as an important pressure boundary for the reactor-loop. The core fuel zone 3 is provided inside the pressure vessel 2 for accommodating core fuel of the nuclear reactor. Further, an IVR (In-vehicle recovery) system is formed In the internal structures of the pressure Vessel 2 and the containment Vessel 1, so that heat In the pressure Vessel 2 can be conducted to the containment Vessel 1, and the containment Vessel 1 can conduct heat to the external environment to realize the heat removal function.

Containment 1 may include a shell body 11, a pit 12, and a water-cooled heat sink 13 in some embodiments. The housing body 11 is a hollow and closed housing for providing a protective structure for a nuclear reactor. The housing body 11 includes a cavity and a stacking pit 12 which are communicated, and the stacking pit 12 is closer to the bottom of the housing body 11 than the cavity. Specifically, the cavity is at the upper middle portion of the housing body 11, and the pit 12 is at the bottom of the housing body 11. Further, referring to fig. 1, the cavity and the pit 12 may be defined by a plane where the top 121 of the wall of the pit 12 is located, wherein a space above the top 121 of the wall of the pit 12 is the cavity, and a space below the top 121 of the wall of the pit 12 is the pit 12.

The pressure vessel 2 is disposed in the pit 12 and forms a gap with the wall surface of the pit 12 for accommodating a water body. The water-cooled heat sink 13 is connected to the housing body 11 and forms a closed circuit for cooling the high-temperature gas in the housing body 11.

The pit 12, the pressure vessel 2 and the gap between them form an IVR system for injecting water into the pit 12 after an accident and removing heat from the interior of the pressure vessel 2 by natural convection. It will be appreciated that the wall top 121 of the pit 12 is higher than the top elevation of the core fuel zone 3 so that the water in the pit 12 can completely submerge the core fuel zone 3. Wherein the elevation represents the height of each part of an object, the bottom elevation represents the elevation value of the bottom surface of the object, and the top elevation represents the elevation value of the top surface of the object.

As also shown in fig. 1, the housing body 11 may be made of prestressed concrete or steel in some embodiments; the bottom datum line of the shell body 11 is lower than the ground and is submerged, namely, a part of the shell body 11 is positioned below the ground, or can be positioned below the ground, the distribution position of the shell body 11 is not limited to the layout shown in the figure, and only the bottom datum plane of the shell body 11 and the ground form a sufficient height difference so as to meet the position matching relation of the shell body 11 and the water-cooling heat sink 13.

The water-cooled heat sink 13 may include, in some embodiments, an input channel 131, an output channel 132, a heat exchanger 133, a water sump 134, an isolation valve 135, and a circulation pump 136. The input channel 131 and the output channel 132 are respectively connected to the shell body 11, and the height of one end of the input channel 131 connected to the shell body 11 is higher than that of one end of the output channel 132 connected to the shell body 11, specifically, the input channel 131 is communicated with the middle-upper space of the shell body 11, the output channel 132 is communicated with the bottom space of the shell body 11, that is, the input channel 131 is communicated with the cavity, and the output channel 132 is communicated with the stacking pit 12, so as to provide structural support for water vapor circulation in the closed loop.

The heat exchanger 133 may be a heat pipe type heat exchanger in some embodiments, arranged in a tube bundle, communicated through an upper header and a lower header, and disposed in the water tank 134 and immersed in the water body of the water tank 134 for transferring heat in the shell body 11 to the water tank 134; it may include an inlet end and an outlet end which are disposed opposite to each other up and down, the inlet end is connected to the input channel 131, the outlet end is connected to the output channel 132, and it is understood that the heat exchanger 133 is respectively communicated with the inner space of the case body 11 through the input channel 131 and the output channel 132; where the tube bundle is oriented vertically or inclined in the basin 134 with the inlet end higher than the outlet end, it will be appreciated that hot gases enter the heat exchanger 133 from the inlet channel 131 and, after cooling, condensed water in the tube bundle can flow automatically into the outlet channel 132.

In some embodiments, the bottom elevation of the heat exchanger 133 is higher than the wall top 121 of the pit 12, which facilitates the condensate within the tube bundle to flow into the pit 12 by height differences, which can further reduce power consumption. It will be appreciated that the body of water within the pit 12 need not completely fill the entire volume of the pit 12, and that only the body of water is required to submerge the core fuel zone 3 to achieve the heat exchange effect, and therefore, in some embodiments, the bottom elevation of the heat exchanger 133 need only be guaranteed to be higher than the top elevation of the core fuel zone 3.

As shown in fig. 1 and 2, the water reservoir 134 is in some embodiments open for heat transfer with the heat exchanger 133; in addition, a sufficient height difference is reserved between the bottom datum plane of the shell body 11 and the ground, so that the height of the water pool 134 can be flexibly arranged, and the water pool 134 can be a negative digging water pool, a water pool above the ground, a water pool below the ground and a water pool above the ground; the water tank 134 may be disposed around the shell 11, may be a dedicated water tank or may be a water tank shared with other systems, without placing the water tank 134 on top of the shell 11 or attaching to the upper portion of the shell 11, so as to reduce the load and vibration-proof requirements of the shell 11; it will be appreciated that the location of the distribution of the water pools 134 is not limited to the illustrated arrangement, as long as the same or similar functions are achieved.

Isolation valves 135 may be disposed on the input and

output channels

131, 132, respectively, in some embodiments, proximate to the penetrations of the input and

output channels

131, 132 and the housing body 11, respectively, for controlling the conduction of the closed loop. It will be appreciated that the location of the isolation valve 135 is not limited to the illustrated arrangement, and may be provided either internally or externally to the housing body 11, as long as the same or similar functions are achieved.

As shown in fig. 1 and 2, the circulation pump 136 is disposed on the input channel 131 or the output channel 132 for providing power for the water vapor circulation in the closed loop, and meanwhile, the circulation pump 136 reduces the stagnation of non-condensable gases (such as air and hydrogen) in the heat exchanger 133, so as to enhance the condensation effect and facilitate the heat discharge. Specifically, at least one row of closed circulation loop system is formed between the inner space of the shell body 11 and the water-cooling heat sink 13, and at least one circulation pump 136 is arranged in each row of circulation loop to drive the water vapor in the loop to circulate. It will be appreciated that the circulation pump 136 may be an air compression pump, a fan or other alternative pump, and that the location of the distribution is not limited to the illustrated arrangement nor the number is limited to the number illustrated, so long as the same or similar functions are achieved.

In some embodiments, when the pressure vessel 2 is in a normal operation state, the isolation valve 135 and the circulation pump 136 are in a closed state; in the event of an accident, the isolation valve 135 and the circulation pump 136 are in an open state.

In some embodiments, the pressure difference is close to zero at the end of the input channel 131 and the output channel 132 respectively communicated with the interior of the shell body 11, and the water vapor can be driven to circulate in the closed loop by only providing small power by the circulating pump 136 through the height difference of the condensed water. It should be understood that the distribution positions of the input channels 131 and the output channels 132 are not limited to the illustrated arrangement, the two channels may be connected to the inner wall of the housing body 11 or enter the housing body 11, and the positions of the two channels penetrating the housing body 11 are not limited to the illustrated positions; in addition, the two passages may have bent pipes or three-way connection portions, and the structure thereof is not limited to that shown in the drawings as long as the same or similar functions can be achieved.

In some embodiments, the output channel 132 includes two opposite ends, and the height of the end connected to the heat exchanger 133 is higher than or equal to the height of the end connected to the housing body 11, that is, the height of the inlet end of the output channel 132 is higher than or equal to the height of the outlet end, and the output channel 132 is in a descending state or a horizontal state from the heat exchanger 133 to the pit 12, so that the condensate water can flow into the pit 12 automatically, and thus the power consumption can be reduced. It will be appreciated that the output channel 132 is slightly elevated from the heat exchanger 133 to the pit 12, and that condensate water can also flow into the pit 12 under the drive of the circulation pump 136, and the distribution is not limited as long as the same or similar functions are possible.

In some embodiments, a circulation loop system is formed between the water-cooled heat trap 13 and the shell body 11, specifically, after an accident occurs, the isolation valve 135 and the circulation pump 136 are opened, a refueling water tank (not shown) of the ivr system fills water in the stack pit 12 and submerges the core fuel area 3, and heat is led out from the pressure vessel 2, the water is heated and evaporated into water vapor and diffuses into the middle-upper space inside the shell body 11, that is, the water is heated and evaporated into water vapor and diffuses into the cavity, and in addition, a loop break may also continuously release a large amount of high-temperature water and water vapor; under the drive of the circulating pump 136, the water vapor enters the heat exchanger 133 through the input channel 131, the heat exchanger 133 transfers the heat of the water vapor to the water tank 134 and the atmosphere, the water vapor is cooled into condensed water, and the condensed water automatically flows into the output channel 132 and the pit 12; the condensed water is heated and evaporated into water vapor, and participates in the cycle again.

It is to be understood that the above examples only represent preferred embodiments of the present invention, which are described in more detail and are not to be construed as limiting the scope of the invention; it should be noted that, for a person skilled in the art, the above technical features can be freely combined, and several variations and modifications can be made without departing from the scope of the invention; therefore, all changes and modifications that come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Claims

1. A submerged containment vessel with an active water cooled heat sink, comprising:

the shell comprises a shell body, wherein the bottom datum plane of the shell body is lower than the ground, a cavity and a stacking pit are communicated with each other in the shell body, and the stacking pit is closer to the bottom of the shell body than the cavity; and

the water-cooling heat trap comprises an input channel, an output channel, a circulating pump, a water tank arranged outside the shell body and a heat exchanger arranged in the water tank, wherein two opposite ends of the heat exchanger are respectively connected with the input channel and the output channel; the input channel and the output channel are respectively connected to the shell body, the input channel is communicated with the cavity, the output channel is communicated with the stacking pit, and a closed loop is formed between the shell body and the water-cooling heat trap; the circulating pump is arranged in the input channel and/or the output channel so as to drive the water vapor in the closed loop to circulate.

2. The submerged containment with active water cooled heat sink of claim 1, wherein the heat exchanger comprises oppositely disposed inlet and outlet ends, the inlet end being higher than the outlet end; the inlet end is connected with the input channel, and the outlet end is connected with the output channel.

3. The submerged containment vessel with active water cooled heat sink of claim 1, wherein the bottom elevation of the heat exchanger is higher than the top of the wall of the pit.

4. The submerged containment with active water cooled heat sink of claim 1, wherein the height of the inlet end of the output channel is greater than or equal to the height of the outlet end of the output channel.

5. The submerged containment vessel with an active water cooled heat sink of claim 1, wherein the basin is disposed at a perimeter of the hull body, and wherein the heat exchanger is disposed within the basin and submerged in a body of water of the basin.

6. The submerged containment with active water cooled heat sink of claim 5, wherein the basin is above or below ground.

7. The submerged containment vessel with an active water cooled heat sink of claim 1, wherein isolation valves are provided on the input and output channels, respectively, to control the conductance of the closed loop.

8. The submerged containment with active water cooled heat sink of claim 1, wherein a pressure vessel is disposed within the pit and a core fuel zone is disposed within the pressure vessel, the top of the wall of the pit being higher than the top level of the core fuel zone.

9. The submerged containment with active water cooled heat sink of claim 8, wherein the bottom elevation of the heat exchanger is higher than the top elevation of the core fuel zone.

10. The submerged arc furnace with active water-cooled heat sink of claim 8, wherein the pressure vessel has a gap with the wall of the pit, the output channel is in communication with the gap, and an in-pile melt retention system is formed between the pressure vessel and the pit.