JPH05256981A - Fast breeder reactor - Google Patents

Abstract

PURPOSE:To control the flow pattern in a intermediate heat exchanger vessel and suppress swinging and waving of free surface. CONSTITUTION:To direct the downward jet flow out of the intermediate heat exchanger inlet pipe 23 in an intermediate heat exchanger vessel 22 containing an intermediate heat exchanger 15 to the intermediate heat exchanger 15 side, a flow guide 30 consisting of an oblique plate 30a and a plurality of vertical plates 30b, 30c is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fast breeder reactor, and in particular, an intermediate heat exchanger (hereinafter referred to as IHX) is housed in an independent container having a liquid surface, and a primary system coolant inflow pipe is provided from above. After being inserted and discharged as a jet below the liquid surface, I
The present invention relates to a top entry loop type fast breeder reactor which enters the HX and exchanges heat with a secondary system.

[0002]

2. Description of the Related Art Generally, a top-entry loop type fast breeder reactor has a core, a pump and an IHX each housed in a container having an independent liquid level, and each container is connected by an inverted U-shaped pipe to form a circulation flow path. Is forming.

First, the structure of a conventional top entry loop type fast breeder reactor will be described with reference to FIG. In FIG. 4, the reactor vessel 3 accommodating the core 1 is divided into a hot plenum 5 and a cold plenum 6 by an intermediate plenum 4, and the hot plenum 5 is provided with an inverted U-shaped IHX inlet pipe connected to the IHX vessel. ing.

A high pressure plenum 2 is provided below the core 1 in the cold plenum 6, and a reverse U-shaped furnace vessel inflow pipe 8 is also connected from the pump vessel 10. I
The IHX container 22 for housing the HX15 is also divided into a hot plenum 19 and a cold plenum 21 by a partition wall 20, and an inverted U-shaped IHX inlet pipe 23 connected to the reactor vessel 3 is provided in the hot plenum 19. ing.

In the cold plenum 21, there is provided an inverted U-shaped IHX outlet pipe 11 connected to the pump container 10.
The pump container 10 containing the pump 9 is also divided into an upper plenum 12 and a lower plenum 13 by a partition wall 14, and the lower plenum 13 has an IHX outlet pipe 11 connected to the IHX container 22 and a reactor container inflow connected to the reactor vessel 3. A pipe 8 is provided.

Next, the flow of the coolant will be described with reference to FIGS. 4 and 5. First, liquid metal sodium, which is a coolant having a high temperature in the core 1, circulates in the hot plenum 5, flows through the IHX inlet pipe 23, and flows into the hot plenum 19 in the IHX container 22. After circulating inside, it rises inside the flow skirt 16 and flows into the IHX 15 through the inlet window 17 of the IHX.

Then, heat is exchanged with the liquid metal sodium of the secondary cooling system through the heat transfer tube 18, cooled, and discharged from the lower part of the IHX 15 to the cold plenum 21 in the IHX container 22,
It is led to the pump suction plenum through the HX outlet pipe 11.

After that, the coolant is pressurized by a pump 9 installed in a pump vessel 10, passes through a reactor vessel inflow pipe 8, enters a high pressure plenum 2 in a reactor vessel 3, and again passes through a core 1 to be heated. And is circulated to the IHX container 22.

The flow of the coolant in the hot plenum 19 in the IHX container 22 having such a structure is jetted from the IHX inlet pipe 23, collides with the partition wall 20, changes its direction, and flows in the hot plenum 19. It is sucked into the flow skirt 16.

[0010]

As described above, in the hot plenum in the IHX container 22 having the free liquid surface, the flow of the coolant flowing out of the IHX inlet pipe 23 disturbs the flow condition greatly, resulting in a complicated flow. Liquid level at the same time
26 also oscillates greatly, the liquid level fluctuates greatly due to ripples, etc., which may cause the structure to vibrate. In addition, liquid metal sodium used as a coolant has a high thermal conductivity, and the temperature of the structural material at the connection part also changes rapidly with the fluctuation of the liquid level. There is a problem that impairs the soundness of wood. further,
There is a possibility that the cover gas 27 may be entrained due to the large swing or waviness of the liquid surface 26, and when the entrained bubbles reach the core 1, the reactivity acts as a disturbance and the integrity of the core is impaired.

The present invention has been made to solve the above-mentioned problems, and its purpose is to control the flow pattern in the IHX container and to provide high-speed growth having an IHX container capable of suppressing free liquid level fluctuations and ripples. To provide a furnace.

[0012]

The present invention is a nuclear fuel, I
An IHX for storing the IHX in a fast breeder reactor in which the HX and the coolant circulation pump are housed in independent containers each having a liquid level, and the containers are connected by piping to circulate the coolant. It is characterized in that a flow guide including a slanting plate and a plurality of vertical plates is installed so that the direction of the jet flowing downward from the IHX inlet pipe in the container is directed to the IHX side.

Further, a perforated plate is provided in a part of the flow guide so as to block the flow path, and the inflowing coolant is I
It is covered with a flow skirt so that it flows from the lower part to the upper part of the IHX entrance window along the outer shell of the HX.
Further, a flow path regulating ring is provided on the lower end of the flow skirt or on the outer peripheral portion of the flow skirt from the lower end to the liquid surface of the coolant.

[0014]

With this structure, the flow pattern of the IHX in the container is controlled, and the jet flow that flows downward from the IHX inlet pipe flows uniformly toward the IHX side, and the IHX flows from the lower end of the flow skirt to the IHX Since it flows into the interior through the inlet window, the flow reaching the vicinity of the liquid surface in the IHX container is reduced, and the free liquid surface can be suppressed from swinging and waviness, and the structure vibration can be suppressed.

Further, since the fluctuation of the liquid level can be suppressed, the transient thermal stress applied to the structural material at the liquid contact portion of the coolant can be prevented. Further, by suppressing the ripples, it is possible to prevent gas entrainment on the free liquid surface and maintain the integrity of the core.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIGS. 1 and 2, those parts which are the same as those corresponding parts in FIGS. 4 and 5 are designated by the same reference numerals, and a description of the overlapping parts will be omitted.

FIG. 1 is a partial bird's-eye view of a hot plenum portion in an IHX container according to one embodiment of the present invention, and FIG. 2 is a horizontal sectional view near the bottom of the hot plenum in the IHX container in FIG. IHX container 22 as shown in FIG.
IHX inlet piping 23 inserted in the hot plenum 19 of
Below this, a slanting plate 30a for directing the flow ejected downward from this IHX inlet pipe 23 to the IHX15 side, and a slanting plate 30
Vertical plate 30 that regulates the flow that flows on both sides of a and that directly hits the IHX outlet pipe 11 and cold trap 31 shown in FIG.
b and a flow guide 30 composed of a vertical plate 30c for adjusting the flow distribution of the coolant flowing into the flow skirt 16 of the IHX 15.

Next, the operation of this embodiment having such a configuration will be described. First, as shown by the arrow in FIG. 1, the flow of the coolant flowing out of the IHX inlet pipe 23 is the oblique plate.
The direction is bent by 30a and flows in the IHX15 direction.
Further, the vertical plate 30b suppresses the components flowing in the direction of the IHX outlet pipe 11 and the direction of the cold trap 31.

As a result, the conventional IH as shown in FIG.
The flow that has collided with the IHX outlet pipe 11 and the cold wrap 31 generated in the X container 22 and becomes an ascending component and directly reaches the free liquid surface 26 disappears. On the other hand, the flow of the coolant under collision with the IHX15 becomes a direct rising component or a flow along the outer peripheral direction of the IHX15, and both reach the flow skirt 16 and are sucked into the IHX15 through the inlet window 17 as they are.

As described above, most of the flow flowing out of the IHX inlet pipe 23 is an ascending flow along the outer periphery of the IHX 15 and is sucked from the inlet window 17 as it is, so that it directly reaches the liquid surface 26 in the IHX container 22. Is greatly reduced.

Thus, according to this embodiment, the IHX container
There is almost no coolant that directly reaches the free liquid level in 22, and the free liquid level fluctuations and waviness are reduced, and vibration of the structure is suppressed. Further, since the fluctuation of the liquid level is reduced, it is possible to prevent the transient thermal stress applied to the structural material at the liquid contact portion of the coolant. Further, by suppressing the swelling at the free liquid surface, it is possible to prevent the liquid level upper cover gas from being inserted and to maintain the soundness of the core.

FIG. 3 shows a second embodiment of the present invention in which the vertical plate 30c is radially arranged in order to adjust the flow distribution of the coolant to be raised along the outer periphery of the IHX 15. The other parts are the same as those in the first embodiment, and the description thereof will be omitted. This makes it possible to make the flow distribution of the coolant that rises along the outer periphery of the IHX15 more uniform,
Liquid level fluctuation can be suppressed.

According to the present invention, a perforated plate is installed in a part of the flow guide 30 so as to block the flow path according to the above-mentioned embodiment, and the IHX is such that the inflowing coolant is downward along the outer shell of the IHX. Is covered with a flow skirt 16 so as to flow toward the IHX inlet window 17 located above the flow skirt 16, and a flow path regulating ring is provided on the lower end of the flow skirt 16 or on the outer peripheral portion of the flow skirt 16 from the lower end to the liquid surface 26. You can also

As a result, the flow of the coolant reaching the free liquid surface is further reduced, and the fluctuation of the liquid surface can be suppressed.

[0025]

According to the present invention, it is possible to provide a fast breeder reactor having an IHX container capable of controlling the flow pattern in the IHX container and suppressing fluctuations and ripples of the free liquid surface.

[Brief description of drawings]

FIG. 1 is an enlarged bird's-eye view showing a hot plenum portion in an intermediate heat exchanger container in an embodiment of a fast breeder reactor according to the present invention.

FIG. 2 is a horizontal cross-sectional view showing the vicinity of the bottom of the hot plenum in FIG.

FIG. 3 is a horizontal cross-sectional view showing the vicinity of the bottom of the hot plenum in the intermediate heat exchanger container according to the second embodiment of the present invention.

FIG. 4 is a configuration diagram showing a conventional top entry loop type fast breeder reactor.

5 is a bird's-eye view partially showing the flow state of the coolant in the hot plenum in the intermediate heat exchanger container in FIG.

[Explanation of symbols]

1 ... Reactor core, 2 ... High pressure plenum, 3 ... Reactor vessel, 4 ... Intermediate plenum, 5 ... Hot plenum, 6 ... Cold plenum, 7 ... Reactor upper mechanism, 8 ... Reactor vessel inflow piping, 9 ... Pump, 10 ... Pump Container, 11 ... IHX outlet piping, 12 ... Upper plenum, 13 ... Lower plenum, 14 ... Partition wall, 15 ... Intermediate heat exchanger, 16 ... Flow skirt, 17 ... Inlet window, 18 ... Heat transfer tube, 19
... hot plenum, 20 ... bulkhead, 21 ... cold plenum,
22 ... IHX container, 23 ... IHX inlet piping, 24 ... IHX secondary system inlet piping, 25 ... IHX secondary system outlet piping, 26 ... Liquid level, 27
… Cover gas, 30… Flow guide, 30a… Oblique plate, 30
b, 30c ... Vertical plate, 31 ... Cold trap.

Claims (1)

[Claims] 1. A nuclear fuel, an intermediate heat exchanger, and a coolant circulation pump are housed in independent containers each having a liquid level,
In a fast breeder reactor configured to circulate a coolant by connecting each of the vessels with each other, a downward flow from an intermediate heat exchanger inlet pipe in an intermediate heat exchanger vessel that accommodates the intermediate heat exchanger. A fast breeder reactor characterized in that a flow guide comprising a slanted plate and a plurality of vertical plates is installed so that the direction of the jet flow is directed toward the intermediate heat exchanger side.