KR101832067B1 - Coolant tank, and containment passive cooling system including the same - Google Patents

Abstract

The present invention is to provide a coolant tank, and a containment passive cooling system including the same to prevent a containment from being re-pressurized and reheated in the cooling of the containment in case of a design basis accident and a serious accident. The coolant tank includes a storage tank for storing cooling water, a partition part disposed in the storage tank and dividing the interior of the storage tank into first and second storage tanks for separating the cooling water, a first heat exchanger extended from the storage tank to the containment and cooling the containment based on the cooling water, and a second heat exchanger extended from the first storage tank to the outside of the storage tank and cooling the cooling water of the first storage tank.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling water storage tank,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling water storage tank and a nuclear reactor passive cooling system including the same, and more particularly, to a cooling water storage tank for cooling a reactor building and a reactor building passive cooling system including the same.

Generally, in the case of a design basis accident or a major accident at a nuclear power plant, radioactive material is discharged together with steam into the reactor building, which causes the temperature and pressure in the reactor building to rise sharply. Failure to adjust the rising temperature and pressure can destroy the reactor building. Therefore, reactor building cooling system is installed in the reactor building, so that the temperature and pressure that rise when a design basis accident or a serious accident occurs are controlled.

However, it is difficult for the operator to control the cooling system in case of design basis accidents and serious accidents, and there is a problem that the cooling system can not operate properly due to the problems such as the loss of the power for the extinguished power. Therefore, a passive cooling system has been applied. The passive cooling system may include a coolant reservoir installed outside the reactor building and a heat exchanger extending from the coolant reservoir into the reactor building.

This allows the reactor building to be cooled as the heat exchanger operates passively in the event of a design basis accident or major accident. Here, at the beginning of the accident, the thermal energy is smoothly removed by the low temperature of the cooling water. However, when the temperature of the cooling water rises due to the repeated heat exchange, the thermal energy can not be completely removed and the temperature and pressure of the reactor building rise again.

Korean Patent Registration No. 10-1552511 (Reactor Building Passive Cooling System)

It is an object of the present invention to provide a cooling water storage tank for preventing the reactor building from being repressed and reheating in cooling of the reactor building in case of a design basis accident and a serious accident, and a reactor building passive cooling system including the same.

The reactor building passive cooling system according to the present invention is a reactor building passive cooling system that is adjacent to an outer wall of a nuclear reactor building and capable of cooling the nuclear reactor building by passive movement. The nuclear reactor passive cooling system includes: a storage tank for storing cooling water; A first heat exchanger extending from the storage tank to the reactor building to cool the reactor building based on the cooling water, and a second heat exchanger for cooling the reactor building based on the cooling water, And a second heat exchanger extending from the first storage tank to the outside of the storage tank for cooling the cooling water of the first storage tank.

The reactor building passive cooling system may further include an air inflow portion provided on the outer wall of the storage tank for guiding an air flow to the second heat exchanger.

The air inlet may be arranged to surround the second heat exchanger and may be provided in a tube shape having an open top.

The air inlet may be provided in the form of a venturi tube having an open top.

The reactor building passive cooling system may further include a valve provided in the partition to allow cooling water of the second storage tank to flow into the first storage tank when the level of the first storage tank is reduced.

The valve may be provided as a one-way valve for allowing the cooling water of the second storage tank to be introduced into the first storage tank and preventing the cooling water of the first storage tank from flowing into the second storage tank.

The one-way valve may include at least one of a floating valve and a check valve.

The capacity of the first reservoir may be less than the capacity of the second reservoir.

Wherein the reactor building passive cooling system comprises a steam outlet provided in the first storage tank and forming a path for discharging steam generated from the first storage tank to the outside of the storage tank and a steam outlet provided in the second storage tank, And a pressure regulator for maintaining the internal pressure of the second reservoir equal to the external atmospheric pressure irrespective of the pressure.

The first heat exchanger includes an inlet pipe through which coolant flows from the second reservoir, an outlet pipe through which coolant provided from the inlet pipe flows into the first reservoir, and a heat exchanger disposed between the inlet pipe and the outlet pipe can do.

According to another aspect of the present invention, there is provided a cooling water storage tank capable of cooling a building by passive operation. The cooling water storage tank includes a storage tank for storing cooling water and a storage tank for storing cooling water, A first heat exchanger extending from the storage tank to the building and cooling the building based on the cooling water and a second heat exchanger extending from the first storage tank to the outside of the storage tank, And a second heat exchanger for cooling the cooling water in the storage tank.

1 is a conceptual view briefly showing a nuclear reactor passive cooling system according to the present embodiment,
FIG. 2 is a cross-sectional view of the passive cooling system for reactor building according to the present embodiment, taken along the line II '
FIG. 3 is a sectional view schematically showing a cooling water storage tank of a nuclear reactor passive cooling system according to the present embodiment,
FIG. 4 is a cross-sectional view of the cooling water reservoir of the reactor building passive cooling system according to the present embodiment taken along line II-II '
FIG. 5 is a graph showing changes in internal pressure and temperature of a nuclear reactor building using a cooling water storage tank of a conventional passive cooling system,
FIG. 6 is a graph showing changes in internal pressure and temperature of a nuclear reactor building using the cooling water storage tank of the passive cooling system according to the present embodiment,
7 is a flowchart showing the operation of the reactor building passive cooling system according to the present embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, it should be understood that the present invention is not limited to the disclosed embodiments, but may be implemented in various forms, and the present embodiments are not intended to be exhaustive or to limit the scope of the invention to those skilled in the art. It is provided to let you know completely. The shape and the like of the elements in the drawings may be exaggerated for clarity, and the same reference numerals denote the same elements in the drawings.

 FIG. 1 is a conceptual view briefly showing a nuclear reactor passive cooling system according to the present embodiment, and FIG. 2 is a cross-sectional view of a nuclear reactor passive cooling system according to the present embodiment taken along line I-I '.

1 and 2, a reactor building passive cooling system 100 (hereinafter, referred to as a cooling system) according to the present embodiment includes a cooling water storage tank 200.

The cooling water storage tank 200 may be disposed in an upper region of the outer circumference of the reactor building 10. The cooling water storage tank 200 can supply the cooling water to the inside of the reactor building 10 if necessary, and at this time, the cooling water can be supplied by the natural fall even if the main power of the reactor facility is lost, . However, if it is necessary to adjust the flow rate of the cooling water to the inside of the reactor building 10, the height of the cooling water storage tank 200 may be changed.

The number of the cooling water storage tanks 200 is not limited to the number of the cooling water storage tanks 200. The number of the cooling water storage tanks 200 is not limited thereto.

Meanwhile, the first heat exchanger 300 is connected to the cooling water storage tank 200. One side of the first heat exchanger 300 is disposed inside the cooling water storage tank 200 and the other side of the first heat exchanger 300 is extended into the reactor building 10 to cool the reactor building 10 based on cooling water stored in the cooling water storage tank 200. . The first heat exchanger 300 will be described in more detail with reference to the accompanying drawings.

On the other hand, the cooling water accommodated in the cooling water storage tank 200 can be accommodated in the cooling water storage tank 200 while being partitioned. Hereinafter, the cooling water storage tank 200 according to the present embodiment will be described in detail with reference to the accompanying drawings. However, the detailed description of the above-described components will be omitted, and the same reference numerals will be used to describe them.

FIG. 3 is a cross-sectional view schematically showing a cooling water storage tank of the reactor building passive cooling system according to the present embodiment, FIG. 4 is a cross-sectional view of the cooling water storage tank of the reactor building passive cooling system according to the present embodiment cut along the II- Sectional view.

3 and 4, the cooling water storage tank 200 according to the present embodiment includes a storage tank 200a. The storage tank 200a forms an outer shape of the cooling water storage tank 200 and may be supported on the outer wall of the reactor building 10. [ Here, the storage tank 200a forms a space for receiving the cooling water therein, and may be provided as a housing, but the shape of the storage tank 200a is not limited.

Inside the storage tank 200a, a partition 210 for partitioning the receiving space of the cooling water is provided. The partition 210 may be provided as a partition 210a. The partition wall 210a is disposed between the upper wall and the lower wall of the storage tank 200a and is divided into a first storage tank 200aa and a first storage tank 200aa adjacent to the reactor building 10 and a second storage tank 200ab ).

Here, the capacity of the second storage tank 200ab may be set larger than that of the first storage tank 200aa. For example, the capacity of the first storage tank 200aa may be 50% or less of the capacity of the entire storage tank 200a.

The first heat exchanger 300 is connected to the first storage tank 200aa and the second storage tank 200ab. The first heat exchanger 300 includes an outflow pipe 310 connected to the first reservoir 200aa, an inflow pipe 320 connected to the second reservoir 200ab and a second inflow pipe 320b connected between the outflow pipe 310 and the inflow pipe 320 And a heat exchange unit 330 disposed in the heat exchange unit 330. [ The first heat exchanger 300 circulates the cooling water in the second storage tank 200ab toward the first storage tank 200aa so that the cooling of the reactor building 10 is performed.

In the present embodiment, however, the outflow pipe 310 and the inflow pipe 320 of the first heat exchanger 300 are connected to the first reservoir 200aa and the second reservoir 200ab, respectively. However, this is an embodiment for explaining this embodiment, and the outflow pipe 310 and the inflow pipe 320 of the first heat exchanger 300 may extend to the inside of the first storage tank 200aa.

On the other hand, a vapor outlet H1 is formed in the upper wall of the first reservoir 200aa. The steam outlet H1 allows the steam generated as the cooling water in the first storage tank 200aa is heated in the cooling of the reactor building 10 to be discharged to the outside. Thus, it is possible to prevent the storage tank 200a from being damaged or damaged due to a change in internal pressure.

And a water level reduction delay unit 220 may be mounted on the steam outlet H1. The water level reduction delay unit 220 separates the droplets and moisture from the steam discharged from the first storage tank 200aa to the outside air so that the separated water is returned to the first storage tank 200aa.

The water level reduction delay unit 220 may be provided by a wet separator to delay the reduction of the water level of the cooling water in the storage tank 200a and to perform passive cooling of the reactor building 10 for a longer period of time.

On the other hand, the passenger alarm unit 230 may be mounted on the water level reduction delay unit 220. The passive alarm unit 230 may alarm the performance of cooling of the reactor building 10 when a design basis accident and a serious accident occur. When the gas is introduced into the steam outlet H1, the passive alarm unit 230 may cause a sound based on the gas flow to be generated or an alarm lamp to be turned on.

For example, the passive alarm unit 230 may be provided with a sound alarm capable of generating noise according to pressure generation, or an emergency light alarm for lighting an emergency light according to a self-power generation facility such as a propeller rotating according to a gas flow.

However, this is an embodiment for explaining the present embodiment, and the passive alarm unit 230 may be provided in various configurations capable of performing an alarm by passive operation even if power is not supplied from the outside.

The passive alarm unit 230 alerts the occurrence of a cooling failure of the reactor building 10 when a design basis accident and a major accident occur, thereby enabling the occurrence of an accident to be recognized primarily around the periphery, And the degree of decompression can be recognized.

On the other hand, a pressure regulating portion H2 is formed on the upper wall of the second reservoir 200ab. The pressure regulator H2 maintains the internal pressure of the second reservoir 200ab equal to the external atmospheric pressure regardless of the internal pressure of the first reservoir 200aa.

Filters F1 and F2 are mounted on the steam outlet H1 and the pressure regulator H2, respectively. The filters F1 and F2 are installed in the reservoir tank 200a in order to prevent harmful substances such as radioactive substances from entering the reservoir tank 200a from the inside of the reactor building 10 to the outside air when the first heat exchanger 300 is damaged or damaged. Prevent outflow.

Meanwhile, an inlet for connecting the first reservoir 200aa and the second reservoir 200ab may be provided under the partition 210a. This inlet may be provided as a one-way valve 210aa. Way valve 210aa allows the cooling water on the second storage tank 200ab side to flow into the first storage tank 200aa and prevents the cooling water in the first storage tank 200aa from flowing into the second storage tank 200ab.

The one-way valve 210aa may be a floating valve or a check valve, and may be mounted on the partition 210a.

However, the number of the one-way valves 210aa is limited to three. However, the number of the one-way valves 210aa is limited to three, I never do that.

Meanwhile, the one-way valve 210aa forms a path through which the cooling water accommodated in the second storage tank 200ab can be introduced into the first storage tank 200aa.

More specifically, the first reservoir 200aa to which the outlet pipe 310 is connected in the event of a design basis accident and a major accident, quickly reaches the saturation temperature. This contributes to the stabilization of the heat removal performance of the cooling system 100, so that the temperature and pressure of the reactor building 10 are quickly stabilized. The reason why the capacity of the first reservoir 200aa is smaller than the capacity of the second reservoir 200ab as described above is for the purpose of exploiting this effect.

The first storage tank 200aa reaches the saturation temperature and the cooling water accommodated in the first storage tank 200aa is heated and discharged to the outside through the steam outlet H1. Thus, a water level difference is generated between the first storage tank 200aa and the second storage tank 200ab. Accordingly, the cooling water in the second storage tank 200ab flows through the one-way valve 210aa to the first storage tank 200aa to eliminate the water level difference.

Accordingly, the cooling water storage tank 200 keeps the heat removal performance of the cooling system 100 constant from the beginning of the design basis accident and the serious accident, so that the pressure and the temperature of the reactor building 10 are gradually reduced. Therefore, in the conventional cooling system, the temperature and pressure of the reactor building 10 decrease, and the heat removal performance decreases due to the increase of the cooling water temperature, thereby solving the problem that the pressure and the temperature of the reactor building 10 are re-pressurized and reheated .

More specifically, the conventional cooling system and the cooling system 100 according to the present embodiment are compared as follows.

FIG. 5 is a graph showing changes in internal pressure and temperature of a reactor building due to use of a cooling water storage tank of a conventional passive cooling system. FIG. 6 is a graph showing changes in internal pressure and temperature of the reactor building according to the cooling water storage tank of the passive cooling system according to the present embodiment. Fig.

As shown in FIGS. 5 and 6, the conventional cooling system operates with the temperature and pressure rise of the reactor building 10 in the event of a design basis accident and a major accident. At this time, the conventional cooling system can reduce the temperature and pressure of the reactor building 10.

However, in the conventional cooling system, the efficiency of the cooling system 100 is drastically lowered according to the heating of the cooling water after a predetermined time has elapsed. As shown in the section "A " in FIG. 5, there is a problem that the temperature and pressure of the reactor building 10 are raised again. Particularly, in a period where the temperature and pressure of the reactor building 10 for a long period of time rise, the operator can secure additional cooling means in order to prevent repressurization of the nuclear reactor building. At this time, there is a possibility that an incorrect operator action may occur.

However, even if the cooling water accommodated in the first storage tank 200aa is heated, the cooling system 100 according to the present embodiment allows the cooling water accommodated in the second storage tank 200ab to flow naturally into the first storage tank 200aa, do. Accordingly, as shown in FIG. 6, the temperature and pressure of the reactor building 10 are reduced smoothly in the event of a design basis accident and a major accident, and the problem of the temperature and pressure of the reactor building 10 rising again can be solved.

Referring again to FIGS. 3 and 4, a second heat exchanger 400 may be connected to the first reservoir 200aa. The second heat exchanger (400) extends from the outside of the storage tank (200a) into the first storage tank (200aa) through the inflow pipe and the outflow pipe. The second heat exchanger (400) cools the cooling water of the first storage tank (200aa) through the atmosphere. The second heat exchanger 400 may be provided as an air-cooling type heat exchanger, and the cooling performance of the first heat exchanger 300 is improved by cooling the cooling water of the first storage tank 200aa.

In addition, an air inflow part 410 may be provided on the outer wall of the storage tank 200aa. The air inlet 410 is disposed to surround the second heat exchanger 400, and an opening may be formed in the upper portion. Here, the air inlet 410 introduces the air flow to the second heat exchanger 400 to improve the heat exchange performance of the second heat exchanger 400, which may be provided as an air-cooled heat exchanger.

The shape of the air inflow part 410 is not limited, although the air inflow part 410 may be provided in the form of a venturi tube having an open upper part for the purpose of venturi effect.

Hereinafter, the operation of the reactor building passive cooling system according to the present embodiment will be described in more detail. However, the detailed description of the above-described components will be omitted and the same reference numerals will be given.

7 is a flowchart showing the operation of the reactor building passive cooling system according to the present embodiment.

As shown in FIG. 7, the cooling system 100 according to the present embodiment can be operated upon occurrence of a design basis accident and a serious accident (S100). At this time, steam and radioactive materials are discharged from inside the reactor building (10), thereby increasing the temperature and pressure inside the reactor building (10).

Thus, the cooling water in the heat exchanging part 330 is heated, and the heated cooling water flows into the first storage tank 200aa. At this time, the cooling water stored in the second storage tank 200ab flows into the first heat exchanger 300 and is supplied to the heat exchange unit 330. [ In this manner, the cooling system 100 repeats the inflow and outflow and causes the circulation of the cooling water based on the natural force to be performed (S200).

On the other hand, as the time elapses after the occurrence of the design basis accident and the major accident, the temperature of the cooling water in the first storage tank 200aa rises to the breaking point (S300). However, the cooling water stored in the second storage tank 200ab is maintained at the initial temperature in a state where the cooling water does not flow with the cooling water of the first storage tank 200aa.

 In addition, the time to reach the point at which the cooling water is broken in the first storage tank 200aa becomes shorter than the conventional cooling water storage tank having the same capacity as the cooling water storage tank 200 according to the present embodiment. Thus, the cooling system 100 according to the present embodiment is stabilized through a relatively short transient period.

In addition, as the cooling water of the first storage tank 200aa evaporates, the cooling water of the lower temperature of the second storage tank 200ab naturally flows into the first storage tank (S400). Accordingly, the heat removal performance of the cooling system 100 is lowered due to the increase in the temperature of the cooling water accommodated in the first storage tank 200aa, thereby solving the problem that the pressure and temperature of the reactor building 10 are re-pressurized and reheated.

Since the temperature of the first storage tank 200aa rises rapidly as compared with that of the second storage tank 200ab, the second storage tank 200aa is provided with the second heat exchanger 400 so that the heat of the first storage tank 200aa can be continuously removed have. Thus, there is an effect that the overall heat removal amount of the cooling system 100 is increased. In addition, when a venturi is applied to the air inlet 410, the air cooling performance is further increased.

Thus, the cooling water storage tank and the nuclear reactor passive cooling system including the cooling water storage tank can quickly stabilize the performance of the nuclear reactor passive cooling system, thereby preventing performance deterioration of the nuclear reactor passive cooling system.

Also, the cooling water storage tank and the nuclear reactor passive cooling system including the cooling water storage tank can continuously reduce the pressure and the temperature of the nuclear reactor building, and it is possible to suppress the occurrence of the secondary accident such as the destruction of the reactor building.

One embodiment of the invention described above and shown in the drawings should not be construed as limiting the technical idea of the present invention. The scope of protection of the present invention is limited only by the matters described in the claims, and those skilled in the art will be able to modify the technical idea of the present invention in various forms. Accordingly, such improvements and modifications will fall within the scope of the present invention as long as they are obvious to those skilled in the art.

10: Reactor building
100: Reactor building passive cooling system
200: Reactor system
300: first heat exchanger
400; The second heat exchanger

Claims (11)

1. A reactor building passive cooling system adjacent to an outer wall of a nuclear reactor building and capable of passively cooling the nuclear reactor building,
A storage tank in which cooling water is stored;
A partition for partitioning the inside of the storage tank into the first and second storage tanks so that the cooling water is separated;
A first heat exchanger extending from the first reservoir to the reactor building and cooling the reactor building based on the cooling water; And
And a second heat exchanger extending from the first storage tank to the outside of the storage tank for cooling the cooling water in the first storage tank,
Wherein the capacity of the first reservoir is less than the capacity of the second reservoir,
The first heat exchanger
An outlet pipe through which the cooling water is introduced from the second storage tank, an outlet pipe through which the cooling water supplied from the inlet pipe flows into the first storage tank, and a heat exchanger disposed between the inlet pipe and the outlet pipe. Reactor building passive cooling system.
The method according to claim 1,
Further comprising an air inflow portion provided on an outer wall of the storage tank for guiding an air flow to the second heat exchanger.
3. The method of claim 2,
The air inlet
Wherein the first and second heat exchangers are arranged to surround the second heat exchanger and are provided in a tube shape with an open top.
The method of claim 3,
The air inlet
And a venturi tube having an open upper portion.
The method according to claim 1,
Further comprising a valve provided in the partition to allow cooling water of the second storage tank to flow into the first storage tank when the level of the first storage tank is reduced.
6. The method of claim 5,
The valve
Wherein the cooling water in the second storage tank is introduced into the first storage tank and the cooling water in the second storage tank is prevented from flowing into the second storage tank.
The method according to claim 6,
The one-way valve
A floating valve, and a check valve. The reactor building passive cooling system according to claim 1,
delete The method according to claim 1,
A steam outlet provided in the first storage tank and forming a path through which steam generated in the first storage tank is discharged to the outside of the storage tank; And
Further comprising a pressure regulator provided in the second reservoir to maintain the internal pressure of the second reservoir equal to the external atmospheric pressure regardless of the internal pressure of the first reservoir.
delete A cooling water reservoir capable of cooling a building by passive motion,
A storage tank in which cooling water is stored;
A partition for partitioning the inside of the storage tank into the first and second storage tanks so that the cooling water is separated;
A first heat exchanger extending from the first reservoir to the building and cooling the building based on the cooling water; And
And a second heat exchanger extending from the first storage tank to the outside of the storage tank for cooling the cooling water in the first storage tank,
Wherein the capacity of the first reservoir is less than the capacity of the second reservoir,
The first heat exchanger
An outlet pipe through which the cooling water is introduced from the second storage tank, an outlet pipe through which the cooling water supplied from the inlet pipe flows into the first storage tank, and a heat exchanger disposed between the inlet pipe and the outlet pipe. Coolant reservoir.

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