KR101436497B1 - Passive decay heat removal system for liquid metal cooled reactors with enhanced natural circulation cooling capability using a helical type sodium-to-sodium heat exchanger - Google Patents

Abstract

The present invention relates to a complete passive residual heat removal system for a sodium-cooled reactor in which a spiral sodium-sodium heat exchanger is used to enhance the natural circulation cooling performance, and more particularly to an intermediate heat exchanger and a sodium-sodium decay heat exchanger, There is provided a system for totally passive residual heat removal of a sodium-cooled nuclear reactor, characterized in that it includes an integral type residual heat eliminating heat exchanger in which a sodium-to-sodium collapse heat exchanger is spirally provided on an outer circumferential surface of an upper coaxial pipe of a heat exchanger. The residual heat elimination system according to the present invention includes the integrated residual heat elimination heat exchanger, and the concept of designing the passive residual heat elimination design of the sodium-cooled reactor has heretofore had the problem of having a complicated core cooling mechanism with high uncertainty, . In addition, the residual heat elimination system according to the present invention is a passive safety grade residual heat removal system which improves operational reliability and ensures stable emergency residual heat elimination performance so as to prepare for all types of design standard accidents budgeted during the entire operation period of a power plant Simplification of the internal structure of the reactor and optimization of the cooling performance can be achieved through a one-dimensional single circulation flow path structure, thereby contributing to the stable operation of heat removal as well as normal operation.

Description

[0001] The present invention relates to a passive decay heat removal system for a sodium-cooled reactor that enhances natural circulation cooling performance using a spiral sodium-sodium heat exchanger heat exchanger}

The present invention relates to a complete passive residual heat removal system for a sodium-cooled reactor in which a spiral sodium-sodium heat exchanger is used to enhance the natural circulation cooling performance. More specifically, the present invention relates to a sodium- To a passive safety grade residual heat removal system of a nuclear reactor.

Most sodium-cooled reactors that are currently designed usually have a decay in the core following an emergency reactor shutdown in the event of a failure of the normal heat removal path leading to "reactor core-intermediate heat exchanger (IHX) steam generator (SG) heat elimination system to remove heat. Until now, various types of sodium-cooled reactors (liquid metal) have been used in passive safety grade residual heat removal systems for the purpose of enhancing safety. As a part of this, a method of removing residual heat of a reactor using liquid metal such as sodium as a coolant The system is designed to utilize the thermal inertia of the hot pool (hot plenum) located above the reactor core outlet to effectively remove heat from the system by natural circulation of the coolant loop.

On the other hand, in the case of the conventional large-capacity sodium-cooled reactor shown in FIG. 1, a sodium-sodium heat exchanger (DHX) which performs the function of transferring the heat of the primary system to the intermediate- a sodium-to-sodium decay heat eXchanger) was installed and a sodium-air heat exchanger was installed at the top of the nuclear reactor building, and the two heat exchangers were connected to a separate intermediate sodium loop for heat- (Direct Reactor Auxiliary Cooling System (DRACS)) that removes the heat of the primary system coolant inside the reactor vessel using the natural circulation of sodium (more than 20 m) .

At this time, the DRACS design concept of FIG. 1 basically uses a sodium-sodium heat exchanger (DHX) installed to be submerged in a hot pool as a main means of core cooling. The hot coolant of the hot pool heated in the reactor core is cooled by passing through the DHX inlet and passing through the heat transfer tube bundle zone and the cooled primary system sodium is collected at the bottom of the hot pool by the density difference between the fuel assemblies of the core And the incoming sodium coolant cools the fuel assembly by a radial heat transfer process.

In addition, the cooled sodium passing through the DHX mixes directly with the primary system sodium coolant heated in the core exit area, and also functions to lower the temperature of the sodium introduced into the hot pool. Such a cooling mechanism is referred to as "Inter-wrapper flow ", which is a structure as shown in Fig. 2 in the DRACS design concept of the prior art.

However, the prior art inter-wrapper flow requires a large-scale experimental facility for demonstrating the performance of the multidimensional phenomenon inside the sodium coolant plenum. In addition, in order to properly utilize the design of the experimental apparatus and the experimental results, It is known to be a design concept that has large uncertainties and is not easy to guarantee performance in that a detailed evaluation of distortion of the device design must be accompanied.

In addition, the prior art of FIG. 1 needs to simplify the mechanism of cooling the sodium through the DHX to secure the operation reliability and stable performance related to the elimination of the residual heat.

In order to overcome the uncertainty of the prior art shown in Fig. 1, in the prior art shown in Fig. 3, a sodium-sodium decay heat exchanger (DHX) is installed in a pool type sodium- (DHX) using a liquid level difference between the hot and cold pools formed by the head of the primary system pump, the sodium-to-sodium decay heat exchanger (DHX) The DHX unit is installed above the low-temperature, free liquid surface inside the support barrel. This eliminates the direct contact with sodium during normal operation and eliminates unnecessary heat during normal operation without the isolation valve of the intermediate sodium loop for heat treatment or the damper at the inlet / outlet of the airflow channel of the sodium-air heat exchanger (AHX) It is designed to minimize losses.

However, in the prior art shown in Fig. 3, only when the operation of the reactor and the primary system pump is stopped due to the normal heat removal source failure, the primary system sodium and the intermediate loop for heat removal Through the active convection heat transfer process between sodium, the heat of the system can be released to the atmosphere due to the final heat sink. Therefore, it is impossible to provide the core cooling function at the early stage of transition due to the delay time until the full cooling is performed, and when the liquid level of the reactor pool is decreased due to breakage of the reactor vessel, the function can not be performed .

Therefore, it is essential to have a design concept that includes stable heat removal performance for all types of accidents expected during the entire operation period including the operation waiting period, and a design concept including the same.

In addition, one of the most urgent problems to be solved in the prior art shown in FIG. 3 is the operating performance of a fully driven residual heat removal system (PDRC) in the case where the primary system coolant pump is operated without stopping after a reactor shutdown . In this case, since the liquid level of the high-temperature pull and low-temperature pull is maintained by the pump operation and the liquid metal coolant level of the low-temperature pull can not be raised, it is impossible to perform the heat removal function smoothly according to the conventional design concept shown in FIG. There may be a serious disruption in the functioning of the safety system itself.

Therefore, it is necessary to provide a design concept capable of providing a certain amount of heat removal function even when the liquid level difference between the hot and cold pools is maintained. However, in the prior art shown in FIG. 3, I do not describe it.

Another prior art (prior art c) shown in Fig. 4 eliminates the " inter-wrapper flow "which is the main core cooling means in the prior art (a) It is a design concept that was developed by combining the advantage of securing a circulation channel that communicates with the low-temperature pool. In the prior art c, the sodium-to-sodium decay heat exchanger (DHX) is separated from the high-temperature sodium plenum by a nuclear hot-pool region and a reactor barrel core barrel, Place in a pooled (separate and annular sodium region). In this case, in the transitional mode of operation where the primary system pump is stopped, the hot sodium passing through the reactor core rises along the reactor barrel, passing over the top of the reactor barrel and located in the separated and annular sodium region. DHX and cooled by passing through DHX are collected at the bottom of the separated and annular sodium region due to the difference in density of the sodium coolant and lead to local sodium coolant stratification do.

The sodium coolant in the isolated annular spatial sodium zone stratified locally by the cooling system of the prior art c is introduced through the inlet nozzle of the Intermediate Heat Exchanger (IHX) where the inlet is located lower than the DHX outlet nozzle After passing through the IHX tube bundle area, it flows into the low-temperature pool through the IHX exit nozzle, and then flows back to the hot-sodium pool area through the core. The core → high temperature sodium pool → isolated annular space sodium pool → intermediate heat exchanger (IHX) To form a transitional circulation flow path structure composed of " sodium pool to core ". In this case, the transverse multidimensional flow from the DHX outlet to the IHX inlet is formed in the isolated annular space sodium pool outside the high temperature pool separated by the high temperature pool and the reactor barrel, and the temperature difference due to cooling and the resulting density difference The cooled sodium enters the IHX inlet area.

The transitional circulation flow path structure of the prior art c has an uncertainty in the cooling performance in terms of directly cooling the fuel assembly by the circulating flow rate passing through the core through the hot and cold pools, Can be reduced. However, thermal stress caused by stratification by reactor barrels and "Y-piece" structure may cause structural problems, and the soda coolant mixing characteristics in the outer space of the reactor barrel may cause overall system circulation flow rate and thermal capacity But it still has uncertainties in terms of its ability to exert a dominant influence on the market.

In conventional passive safety grade demagnetization systems (PDRC), the heat transfer characteristics in the sodium-sodium decay heat exchanger (DHX) depend on how much hot coolant (sodium) is introduced into the DHX installed in the large hot pool area The heat transfer performance is determined. Therefore, in order to meet design criteria with respect to the elimination of emergency residual heat, a stable supply of sodium coolant to DHX must be ensured during the entire operating period of the plant, including normal operation modes. However, with the DHX installation method disclosed in the prior art a, b, and c as described above, it is difficult to secure a predictable core circulation flow rate of the same type for the entire operation mode of the power plant, And does not provide any countermeasures and coping facilities for securing them.

Therefore, the inventors of the present invention conducted a study to solve the problems of the conventional passive residual heat elimination system, and in order to effectively remove the decay heat generated in the reactor core even when the normal heat removal function is lost, the sodium- The present invention has been accomplished by developing a passive safety grade residual heat removal system for a sodium-cooled reactor capable of stable operation only by natural phenomena without the involvement of an active device or an operator by applying an integrated residual heat eliminating heat exchanger installed on the outer peripheral surface.

Japanese Patent Application Laid-Open No. 10-2004-0100164

It is an object of the present invention to provide a complete passive residual heat removal system of a sodium-cooled reactor in which a spiral sodium-sodium heat exchanger is used to enhance the natural circulation cooling performance.

In order to achieve the above object,

High temperature pools accommodated by high temperature sodium heated by reactor core;

An intermediate heat exchanger for performing heat exchange with sodium in the hot pool;

A sodium-sodium decay heat exchanger contained within the hot pool to remove decay heat inside the reactor;

A sodium-to-air heat exchanger installed at a higher position than the sodium-sodium decay heat exchanger; And

And a mid-sodium loop for heating to connect the sodium to sodium decay heat exchanger and the sodium to air heat exchanger, the system comprising:

An intermediate heat exchanger and a sodium-sodium decay heat exchanger, wherein the sodium-to-sodium decay heat exchanger is spirally provided on an outer circumferential surface of the upper coaxial pipe of the intermediate heat exchanger. A complete passive residual heat elimination system is provided.

In addition,

The present invention provides a sodium-cooled reactor having a reactor core loaded with a plurality of nuclear fuel rods at a lower end of a high temperature pool of the residual heat elimination system.

Further,

The residual heat removal system is used to directly introduce the hot sludge into the sodium-sodium decay heat exchanger and the sodium cooled in the sodium-sodium decay heat exchanger to flow through the intermediate heat exchanger from the hot pool into the cold pool, And removing the residual heat of the reactor.

The residual heat elimination system according to the present invention includes the integrated residual heat elimination heat exchanger, and the concept of designing the passive residual heat elimination design of the sodium-cooled reactor has heretofore had the problem of having a complicated core cooling mechanism with high uncertainty, . In addition, the residual heat elimination system according to the present invention is a passive safety grade residual heat removal system which improves operational reliability and ensures stable emergency residual heat elimination performance so as to prepare for all types of design standard accidents budgeted during the entire operation period of a power plant Simplification of the internal structure of the reactor and optimization of the cooling performance can be achieved through a one-dimensional single circulation flow path structure, thereby contributing to the stable operation of heat removal as well as normal operation.

FIG. 1 is a schematic view showing a residual heat removal system corresponding to the prior art a; FIG.
2 is a schematic view showing a cooling mechanism of the conventional technology a;
FIG. 3 is a schematic view illustrating a residual heat removal system corresponding to the prior art b; FIG.
FIG. 4 is a schematic view illustrating a residual heat removal system corresponding to the prior art c; FIG.
5 is a schematic view illustrating an embodiment of a complete passive residual heat elimination system according to the present invention;
FIG. 6 is a view showing a head portion of a conventional residual heat removal system and a residual heat removal system according to the present invention; FIG.
7 is a view showing a coolant flow path according to a residual heat removal system of the prior art a, b, and c;
FIG. 8 is a view illustrating a coolant flow path according to a completely driven passive heat removal system according to the present invention; FIG.
9 is a schematic view of an integrated residual heat eliminating heat exchanger in a complete passive residual heat elimination system according to the present invention;
10 is a cross-sectional view of a multi-axial annular chamber in a complete passive residual heat removal system according to the present invention;
11 is a view schematically showing still another embodiment of a complete passive residual heat elimination system according to the present invention;
Figure 12 is a perspective view of a completely driven passive heat removal system according to the present invention;
FIG. 13 is a view showing an example of a supporting structure for fixing a helical heat transfer pipe in the complete passive residual heat elimination system according to the present invention. FIG.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings in order to facilitate a person skilled in the art to easily carry out the technical idea of the present invention. . In the drawings, the same reference numerals are used to designate the same or similar components throughout the drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

The present invention

High temperature pools accommodated by high temperature sodium heated by reactor core;

An intermediate heat exchanger for performing heat exchange with sodium in the hot pool;

A sodium-sodium decay heat exchanger contained within the hot pool to remove decay heat inside the reactor;

A sodium-to-air heat exchanger installed at a higher position than the sodium-sodium decay heat exchanger; And

And a mid-sodium loop for heating to connect the sodium to sodium decay heat exchanger and the sodium to air heat exchanger, the system comprising:

An intermediate heat exchanger and a sodium-sodium decay heat exchanger, wherein the sodium-to-sodium decay heat exchanger is spirally provided on an outer circumferential surface of the upper coaxial pipe of the intermediate heat exchanger. A complete passive residual heat elimination system is provided.

FIG. 5 is a schematic view illustrating a system for completely removing the passive residual heat of a sodium-cooled reactor according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a complete passive residual heat removal system of a sodium-cooled reactor according to the present invention will be described in detail with reference to the drawings.

Referring to FIG. 5, a complete passive residual heat elimination system for a sodium-cooled reactor according to the present invention includes a high temperature pool filled with a high temperature sodium heated by a reactor core; An intermediate heat exchanger (IHX) for heat-exchanging with the hot-pool sodium; Sodium decay heat exchanger (DHX) contained within the hot pool to remove decay heat inside the reactor; A sodium-to-air heat exchanger (AHX) installed at a higher elevation than the sodium di-sodium decay heat exchanger (DHX); And an intermediate sodium loop for heat transfer connecting the sodium to sodium decay heat exchanger (DHX) to the sodium to air heat exchanger (AHX).

At this time, the residual heat elimination system according to the present invention includes an integral type residual heat elimination heat exchanger 100 having a spiral shape of a sodium-sodium decay heat exchanger (DHX) on the outer circumferential surface of an upper coaxial pipe of the intermediate heat exchanger (IHX) .

The integrated residual heat eliminating heat exchanger 100 is an integrated unit of an intermediate heat exchanger (IHX) and a decay heat exchanger (DHX). By dramatically simplifying the multi-dimensional coolant flow characteristic inside the high temperature pool to one- The heat removal mechanism of DHX can be utilized effectively. In addition, since the core barrel and the separator Y-piece provided in the prior art c shown in FIG. 4 can be removed, the internal structure of the reactor can be remarkably simplified. Further, as compared in FIG. 6, it is possible to reduce the number of penetration parts of the reactor head compared to the prior art a, b, and c, and to reduce the number of component heads by eliminating the conventional tube- It can also be expected to improve economic efficiency by reducing production / construction / maintenance costs.

At this time, the integrated dehumidification heat exchanger 100 introduces the sodium cooled in the sodium-sodium decay heat exchanger (DHX) from the hot pool to the cold pool through the intermediate heat exchanger (IHX).

That is, the coolant passes through a heat source (RX core), the coolant is hot-pooled, cooled in a sodium-sodium decay heat exchanger (DHX), which is a transient emergency heat sink, sink into the intermediate heat exchanger (IHX), and the sodium cooled through the intermediate heat exchanger enters the low temperature pool. In this way, the integral residual heat eliminating heat exchanger 100 forms a serialized circulation flow path leading to the sodium-sodium decay heat exchanger (DHX) and the intermediate heat exchanger (IHX) It is possible to provide a stable cooling system by providing a direct cooling function on the circulating flow path of the reactor internal sodium coolant regardless of any accident that may occur.

The provision of such a single circulating flow path structure allows for a more efficient circulation of the refrigerant by the formation of a smooth circulation flow rate of the transient primary system coolant compared to the prior art passive residual heat removal system in which the heat removal function via DHX is provided in parallel with the intermediate heat exchanger It is possible to improve not only the cooling performance of the system but also the operational reliability of the safety grade residual heat removal system.

In addition, since the DHF flow rate can be clarified by forming the single circulation flow path as described above through the integrated residual heat eliminating heat exchanger, the uncertainty of the residual heat removal performance can be obtained by optimizing the residual heat removal flow path of the hot pool and simplifying the internal structure of the reactor vessel. To facilitate verification testing and interpretation of the licensing process.

This can be more easily confirmed by comparing the residual heat eliminating flow path of the prior art a, b, and c disclosed in FIG. 7 with the single circulating flow path through the integrated residual heat eliminating heat exchanger of the present invention disclosed in FIG.

That is, as compared to the flow paths of the prior arts a, b, and c disclosed in Fig. 7, the single circulation flow path through the integrated residual heat eliminating heat exchanger of the present invention, as shown in Fig. 8, This is a structure that can exhibit a very simplified and effective cooling performance in terms of directly cooling the core by a circulating flow rate through the core.

9, the sodium-sodium decay heat exchanger (DHX) may be a helical tube provided on the outer circumferential surface of an upper coaxial pipe of the intermediate heat exchanger, 500).

The spiral heat transfer pipe 500 is provided on the upper outer circumferential surface of the intermediate heat exchanger IHX, that is, on the outer circumferential surface of the coaxial pipe of the intermediate heat exchanger, A plurality of helical heat transfer tubes may be provided on the outer circumferential surface of the upper side coaxial pipe so as to intersect with each other.

At this time, the helical heat transfer pipe 500 may be provided so as to be submerged in the high temperature pool, and in particular, the helical heat transfer pipe is always arranged sufficiently lower than the sodium free liquid surface of the high temperature paste. As a result, it is possible to prevent the gas suction from the high temperature full free liquid surface and to cool the high temperature paste sodium in the helical heat transfer tube more efficiently.

In addition, the sodium-sodium decay heat exchanger (DHX) including the spiral heat transfer pipe 500 is connected to the end of the low temperature sodium chamber 203 into which the low temperature sodium of the sodium loop for removing the residual heat is introduced from the sodium-air heat exchanger (AHX) Can be expanded to a position lower than the lowermost end of the helical heat transfer pipe (500), and the lower part of the low temperature sodium chamber (203) can be arranged to be submerged in the high temperature pool.

In the residual heat eliminating system according to the present invention, the integral type residual heat eliminating heat exchanger 100 may include a multi-layered annular chamber 200 as shown in FIG.

That is, the integral type residual heat eliminating heat exchanger 100 may include a multi-axial annular chamber 200 that can be divided into a total of four zones. As shown in FIG. 10, the multi-axial annular chamber 200 At the center of the intermediate heat exchanger (IHX), a low temperature sodium downfalling pipe (201) in which low temperature sodium of the intermediate heat transfer system (IHTS) flows downward and a high temperature sodium uprising pipe (202) A coaxial piping section of the intermediate heat exchanger IHX is provided,

A low temperature sodium chamber 203 and a spiral heat transfer pipe 500 through which the low-temperature sodium of the sodium loop for removing residual heat is introduced from the sodium-to-air heat exchanger (AHX) are connected to the outer side of the upper coaxial piping portion of the intermediate heat exchanger (IHX) The hot sodium chamber 204 through which the heated hot sodium flows out may be provided coaxially with the coaxial piping portion of the intermediate heat exchanger IHX.

The low temperature sodium downfalling pipe 201, the high temperature sodium uptake pipe 202, the low temperature sodium chamber 203 and the high temperature sodium chamber 204 constituting the multi-axial annular chamber 200 have a gap In particular, it is possible to provide a releasable gap between the low-temperature sodium chamber 203 and the high-temperature sodium riser pipe 202 of the intermediate heat exchanger so that the spiral-type heat transfer pipe 500 can be separated and maintained / desirable.

The upper end of the multi-layered annular chamber 200 is designed and arranged so that a nozzle connected to the high temperature pipe and the low temperature pipe of the sodium loop is connected to the sodium loop for removing the residual heat , The design and arrangement of the sodium loop is not particularly limited and can be carried out based on a conventional design.

The hot sodium discharged from the helical heat transfer pipe 500 to the sodium-air heat exchanger (AHX) may be discharged through a hot sodium chamber provided above the reactor baffle 300 as shown in FIG. That is, a hot sodium chamber for discharging hot sodium to the sodium-to-air heat exchanger (AHX) is provided above the reactor baffle (300). This is to prevent the sodium liquid in the hot pool from rising, and it is possible to prevent the sodium in the hot pool from contacting the hot sodium chamber even if the sodium liquid level in the hot pool rises.

11, the residual heat elimination system according to the present invention may further include a support barrel 400 for supporting the integrated residual heat elimination heat exchanger 100. [

The support cylinder 400 serves to facilitate the cooling performance of the decay heat exchanger (DHX) 500 in the spiral heat transfer tube 500 and to supply the siro coolant, which has passed through the helical heat transfer tube area, to the inlet of the intermediate heat exchanger (IHX) 12, a lower portion of the support cylinder 400 is connected to and supported by a horizontal separation plate 600, and an upper portion of the support cylinder 400 is connected to a separate baffle plate 600. [ And can be supported by a baffle plate. At this time, the baffle plate is a plate-like structure having a certain thickness immersed in the high-temperature paste. The baffle plate is not connected to any structure on the core, but merely connects the upper ends of the plurality of support cylinders 400, And may be provided to be connected to the vertically standing reactor baffle 300 to support the support cylinder 400. The baffle plate 300 is provided only for supporting the upper part of the support cylinder 400. The baffle plate 300 has no influence on the flow path through which the coolant flows and does not affect the flow path through which the coolant flows And may be provided in a suitable form to support the upper portion of the support cylinder 400.

The support tube 400 is a space capable of flowing to the inlet of the intermediate heat exchanger IHX after passing through the lower end of the sodium di-sodium decay heat exchanger (DHX) So that the sodium coolant can flow smoothly to the inlet of the intermediate heat exchanger (DHX).

In the residual heat removal system according to the present invention, the spiral heat transfer pipe 500 of the sodium-sodium decay heat exchanger (DHX) may be fixed and supported through the support structure 700.

That is, when there are a plurality of spiral heat transfer tubes 500, the spiral heat transfer tubes may be deformed or damaged due to their weight. Therefore, the residual heat elimination system of the present invention may further include a support structure 700 capable of fixing and supporting the helical heat transfer pipe 500, and the support structure may be formed of, for example, a spiral heat transfer pipe And a plurality of holes through which the heat transfer tubes corresponding to the respective rows of the heat transfer tubes 500 may pass.

However, the support structure 700 is not limited thereto, and if the spiral type heat transfer tube 500 can be fixed and supported, the spiral type heat transfer tube 500 can be appropriately deformed and processed.

Meanwhile, in the residual heat elimination system according to the present invention, the integrated residual heat elimination heat exchanger 100 may be provided with a low-temperature sodium inlet and a high-temperature sodium outlet together in one reactor head, (DHX) and an intermediate heat exchanger (IHX) are provided in parallel to solve the problem that the structure and the mechanism are complicated, thereby simplifying the structure of the residual heat removal system and optimizing the cooling performance. have.

In addition,

The present invention provides a sodium-cooled reactor having a reactor core loaded with a plurality of nuclear fuel rods at a lower end of a high temperature pool of the residual heat elimination system.

Hereinafter, the sodium-cooled reactor according to the present invention will be described in detail.

The sodium-cooled nuclear reactor according to the present invention comprises a single pass heat exchanger including an intermediate heat exchanger and a sodium-sodium decay heat exchanger, wherein the sodium-sodium disintegration heat exchanger is coaxially provided on the upper circumferential surface of the intermediate heat exchanger, A residual heat removal system is provided,

Since the residual heat elimination system includes the integrated residual heat elimination heat exchanger, the coolant passes through the reactor core which is a heat source, is cooled in a sodium-sodium decay heat exchanger, which is a heat sink of the transient high temperature pool, (IHX) which is a normal heat sink, and the sodium cooled by the intermediate heat exchanger flows into the low temperature pool. In this way, the integrated residual heat eliminating heat exchanger forms a serialized circulation flow path leading to the sodium-sodium decay heat exchanger and the intermediate heat exchanger. Accordingly, the sodium- It is possible to provide a direct cooling function on the circulating flow path of the reactor internal sodium coolant regardless of an accident, thereby providing a stable cooling system.

Further,

The residual heat removal system is used to directly introduce the hot sludge into the sodium-sodium decay heat exchanger and the sodium cooled in the sodium-sodium decay heat exchanger to flow through the intermediate heat exchanger from the hot pool into the cold pool, And removing the residual heat of the reactor.

As described above, the residual heat elimination system includes an integral remanufacturing heat exchanger including an intermediate heat exchanger and a sodium-sodium decay heat exchanger, wherein an upper side peripheral surface of the intermediate heat exchanger is coaxially provided with a sodium-sodium disintegration heat exchanger , The integrated remanufacturing heat exchanger can efficiently cool the sodium as the coolant through the following cooling path.

After the integrated dehumidification heat exchanger is cooled in a sodium-sodium decay heat exchanger of an integral-type dehumidification heat exchanger, which passes through a reactor core that is a heat source and the coolant passes through a hot pool and is a transient emergency heat sink, Sodium that has flowed into the intermediate heat exchanger (IHX), which is a normal heat sink, and passed through the shell-side flow path of the intermediate heat exchanger, which has lost its cooling function due to loss of the normal heat eliminating function, .

In general, when the reactor is operating normally, the normal heat removal path consisting of reactor core → high temperature pool → intermediate heat exchanger (IHX) → low temperature pool → reactor core can be operated to cool the coolant sodium, The normal heat removal path can not be operated effectively.

However, in the method of removing the residual heat of the reactor according to the present invention, the residual heat eliminating system including the integrated residual heat eliminating heat exchanger is used to perform the heat recovery from the reactor core to the high temperature pool to the collapse heat exchanger (spiral heat exchanger) to the intermediate heat exchanger (IHX) (IHX) can be continuously provided with the cooling function of the decay heat exchanger even if the heat removal function of the intermediate heat exchanger (IHX) is lost due to the power shutdown due to the transient operation of the transient circulation channel composed of the reactor core, It is possible to secure a stable heat removal performance of the heat exchanger.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but many variations and modifications may be made without departing from the scope of the present invention. It will be understood that the invention may be practiced.

IHX: intermediate heat exchanger
DHX: Decay Heat Exchanger
RX core: reactor core
AHX: Sodium-Air-Heat Exchanger
UIS: Upper Internal Structure
100: Integrated type residual heat removal heat exchanger
200: Multi-layered annular chamber
201: Low temperature sodium down pipe
202: High temperature sodium uptake tube
203: low temperature sodium chamber
204: Hot Sodium Chamber
300: reactor baffle
400: Support tube
500: Spiral tube
600: Horizontal separator
700: support structure

Claims (17)

High temperature pools accommodated by high temperature sodium heated by reactor core;
An intermediate heat exchanger for performing heat exchange with sodium in the hot pool;
A sodium-sodium decay heat exchanger contained within the hot pool to remove decay heat inside the reactor;
A sodium-to-air heat exchanger installed at a higher position than the sodium-sodium decay heat exchanger; And
And a mid-sodium loop for heating to connect the sodium to sodium decay heat exchanger and the sodium to air heat exchanger, the system comprising:
And an integrated dehumidifying heat exchanger including an intermediate heat exchanger and a sodium-sodium decay heat exchanger, wherein a sodium-to-sodium decay heat exchanger is spirally provided on an outer circumferential surface of an upper coaxial pipe of the intermediate heat exchanger,
The sodium-sodium decay heat exchanger includes a helical tube,
Wherein the hot sodium introduced into the sodium-to-air heat exchanger from the helical heat transfer tube flows out through a hot sodium chamber provided above the reactor baffle.
The integrated desalination heat exchanger according to claim 1, wherein the integrated dehumidification heat exchanger constitutes a flow path for introducing the high-temperature full-sodium into the low-temperature pool through the intermediate heat exchanger after cooling in the sodium-sodium decay heat exchanger. Residual heat removal system.
delete 2. The sodium-cooled reactor as claimed in claim 1, wherein the spiral heat transfer tubes are provided on the outer circumferential surface of the upper coaxial pipe of the intermediate heat exchanger in such a manner that a plurality of helical heat transfer tubes are alternately rotated in different directions. Residual heat removal system.
The system according to claim 1, wherein the helical heat transfer pipe is provided so as to be submerged in the high temperature pool, wherein the helical heat transfer pipe is disposed lower than the sodium free liquid surface of the high temperature paste.
The heat exchanger according to claim 1, wherein the sodium-sodium decay heat exchanger extends from the sodium-to-air heat exchanger such that the end of the low temperature sodium chamber into which the low temperature sodium of the sodium loop for removing the residual heat is introduced is lower than the lowermost end of the helical heat transfer tube, Wherein the lower portion of the low temperature sodium chamber is arranged to be submerged in the high temperature pool.
delete 2. The heat recovery unit according to claim 1, wherein the integrated residual heat eliminating heat exchanger
A low temperature sodium downfalling pipe in which the low temperature sodium of the intermediate heat transfer system (IHTS) flows downward in the intermediate heat exchanger;
A coaxial piping portion of an intermediate heat exchanger (IHX) comprising a hot sodium riser pipe through which hot sodium flows upward;
At the outer side of the upper side coaxial piping portion, a low-temperature sodium chamber into which low-temperature sodium of the sodium loop for removing the residual heat is introduced from the sodium-to-air heat exchanger; And
And a high-temperature sodium chamber through which hot high-temperature sodium flows while passing through a helical heat transfer tube are sequentially arranged.
9. The method of claim 8, wherein the annular structure is a multi-layered annular chamber structure consisting of a low-temperature sodium downcomer, a coaxial tubing, a low temperature sodium chamber, and a hot sodium chamber. Passive residual heat removal system.
9. The system of claim 8, wherein in the annular structure, the low temperature sodium downfalling pipe, the coaxial piping, the low temperature sodium chamber and the hot sodium chamber are provided with a gap for thermal isolation. .
The system of claim 1, wherein the sodium-sodium decay heat exchanger further comprises a support structure for fixing the helical heat transfer tube.
12. The system of claim 11, wherein the support structure is a plate-like structure having a predetermined thickness including a plurality of holes through which heat transfer tubes corresponding to respective rows of the helical heat transfer tubes can pass, Residual heat removal system.
The system of claim 1, wherein the residual heat elimination system further comprises a support barrel for supporting the integral remanufacturing heat exchanger.
14. The method of claim 13, wherein the support tube is in an expanded form so as to have a space capable of flowing to the inlet of the intermediate heat exchanger after passing through the lower end of the high temperature pooled sodium di-sodium decay heat exchanger. A complete passive residual heat removal system for a cooling reactor.
14. The system of claim 13, wherein the lower end of the support tube is connected to a horizontal separator plate and the upper end of the support tube is connected to a baffle plate.
16. The method of claim 15, wherein the baffle plate is a plate-like structure that is submerged in a high-temperature pool. The baffle plate is connected to the reactor baffle to connect the upper ends of the plurality of support bases, A complete passive residual heat removal system for a nuclear reactor.
The residual heat removal system of claim 1 is used to direct the hot sludge into the sodium-sodium decay heat exchanger and the sodium cooled in the sodium-sodium decay heat exchanger into the hot pool from the hot pool through the intermediate heat exchanger, Wherein the residual heat is passively removed.

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