JPS585400B2 - Heat retention device for equipment or piping - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a guard vessel, and more particularly to a heat insulating device for equipment or piping that allows easy maintenance and inspection of equipment or piping inserted into the guard vessel.

Guard vessels are installed around equipment or piping to limit the amount of sodium, a coolant, leaking from equipment and piping in the primary cooling system of fast breeder reactors, and to prevent accidents involving loss of primary coolant in the reactor. be done.

The primary cooling system of a fast breeder reactor consists of a reactor vessel containing the reactor core, an intermediate heat exchanger, a sodium pump, and other equipment, and these devices are connected via piping to the reactor vessel, intermediate heat exchanger, sodium pump, It is configured by being connected in the order of the reactor vessel.

The guard vessel is installed to cover the lower part of the reactor vessel, intermediate heat exchanger, and sodium pump.

An example of a guard vessel is shown in FIG.

Reference numeral 1 denotes an intermediate heat exchanger whose upper portion is attached to the operation floor 2 within the containment vessel.

A preheater 3 is provided around the intermediate heat exchanger 1 .

A heat insulating material 4 is attached to the outside of the preheater 3 so as to cover the intermediate heat exchanger 1.

The lower part of the intermediate heat exchanger 1 is inserted into the guard vessel 5.

The guard vessel 5 is installed on a support member 6 fixed to a floor surface 7.

A preheater 8 is attached to the outer surface of the guard vessel 5.

A heat insulating material 9 is attached outside the preheater 8 so as to surround the guard vessel 5.

A drain pipe 10 is inserted into a space 11 formed within the guard vessel 5 between the surface of the heat insulating material 4 and the inner surface of the guard vessel 5.

The preheater 3 is provided to preheat the intermediate heat exchanger 1 to about 200° C. or higher when filling the intermediate heat exchanger 1 with sodium.

When the intermediate heat exchanger 1 is damaged and the sodium inside leaks, this sodium accumulates in the space 11 within the guard vessel 5.

The level of the upper end of the guard vessel 5 is higher than the upper end of the reactor core within the reactor vessel.

Guard vessels such as those described above are also arranged below the reactor vessel, sodium pump, etc., but the upper ends of these guard vessels are also located at a higher level than the upper end of the reactor core.

This prevents a loss of coolant accident in which the reactor core is exposed due to sodium leaking from the primary cooling system.

In order to ensure the above function, the guard vessel 5 is required to limit the volume of the space 11 to a certain limit value or less.

If the volume of the space 11 is increased, a large amount of sodium in the primary cooling system will leak and the reactor core will be exposed.

Sodium that has leaked and remained in the guard vessel 5 and solidified is melted by the preheater 8 and further taken out of the guard vessel 5 by the drain pipe 10.

On the other hand, since it is necessary for a person to enter the space 11 during maintenance and inspection of the intermediate heat exchanger 1, the volume of the space 11 cannot be made very small.

The volume of the space 11 within the guard vessel 5 is determined to satisfy these requirements.

During periodic maintenance and inspection of the intermediate heat exchanger 1, an inspection is performed to see if there is any abnormality in the welded portion of the container of the intermediate heat exchanger 1.

At this time, the preheater 3 and the heat insulating material 4 covering the surface of the intermediate heat exchanger 1 are removed.

It is not easy to perform such work in the narrow space 11 inside the guard vessel 5.

When the maintenance and inspection of the intermediate heat exchanger 1 is completed, the preheater 3 and the heat insulating material 4 are attached to the surface of the intermediate heat exchanger 1 again.

This type of work is also carried out in the narrow space 11 inside the guard vessel 5.
It will be held at

Maintenance and inspection takes time, and maintenance and inspection cannot be carried out easily.

SUMMARY OF THE INVENTION An object of the present invention is to provide a heat insulating device for equipment or piping that eliminates the above-mentioned conventional drawbacks and allows easy maintenance and inspection of the portion of the equipment or piping inserted into the guard vessel.

A feature of the present invention is that a first tube is placed on the outside of a guard vessel into which equipment or piping containing liquid metal is inserted from above.
A heater and a first heat insulating material are installed, a second heater and a second heat insulating material are installed outside the guard vessel and outside the equipment or piping, and the annular gap formed between the second heat insulating material and the guard vessel is covered. This is due to the fact that a member has been provided.

A preferred embodiment of the present invention will be described based on FIGS. 2 and 3.

The same configuration as the conventional one is indicated by the same reference numeral, and different parts will be explained.

The intermediate heat exchanger 1 is inserted into the guard vessel 12 from above.

The guard vessel 12 is a container 13 with an open top.
and a lid 14 attached to the top of the container 13.

The container 13 is fixed on the support member 6.

A preheater 8 is attached to the side surface of the container 13, and a heat insulator 9 is attached to cover the preheater 8.

A drain pipe 10 is inserted into a space 20 formed between the intermediate heat exchanger 1 and the container 13 within the container 13 .

The drain pipe 10 penetrates the container 13 and the heat insulating material 9 and is taken out to the outside.

On the other hand, the lid 14 consists of a fixed ring part 15 and a movable cylindrical part 16.

The fixing ring part 15, which has a two-split structure, is attached to the container 1.
3 with flange bolts, and protrudes into the gap 21 formed between the intermediate heat exchanger 1 and the side wall of the container 13.

The movable cylinder 16 is placed on the fixed ring part 15.

An annular protrusion 17 that protrudes toward the intermediate heat exchanger 1 is provided at the upper portion of the movable cylindrical portion 16 .

The movable cylindrical portion 16 is also divided into two for easy installation, and when installed on the fixed ring portion 15, it is integrated with bolts.

A preheater 3 is attached to a portion of the intermediate heat exchanger 1 that exists outside the container 13.

A heat insulating material 18 is attached to cover the outside of the intermediate heat exchanger 1 to which the preheater 3 is attached.

The heat insulating material 18 is not attached to the portion of the intermediate heat exchanger 1 that exists inside the container 13.

A heat insulating material 18 is provided between the fixed ring portion 15 and the annular protrusion 17.
There is a lower end of .

An annular protrusion 19 that protrudes toward the movable cylindrical portion 16 is formed at the lower end of the heat insulating material 18 .

A gap 22 formed between the annular protrusion 19 and the movable cylindrical part 16 and a gap 23 formed between the annular protrusion 17 and the heat insulating material 18 prevent thermal expansion of the intermediate heat exchanger 1 in the radial direction. It has a width that can be absorbed.

When filling the intermediate heat exchanger 1 with sodium, the intermediate heat exchanger 1 is preheated by the preheater 3 and the preheater 8.

The preheater 8 first heats the air in the space 20 and heats the intermediate heat exchanger 1.

It is attached to the top of the container 13. Since the lid 14 consisting of the fixed ring part 15 and the movable cylindrical part 16 covers the gap 21, there is little heat radiation from inside the container 13.

Heat radiation from inside the container 13 takes place through the gaps 22 and 23, but the amount is small.

Therefore, the intermediate heat exchanger 1 is sufficiently heated by the preheater 8 as well.

The preheater 8 is used to preheat the intermediate heat exchanger 1 when filling the interior with sodium, and to preheat the container 13 when draining sodium leaked into the container 13.

During operation of the fast breeder reactor, the lower end of the intermediate heat exchanger 1 moves approximately 13 cm in the axial direction due to thermal expansion.

The portion where the lid 14 is attached moves downward by a submultiple.

Even if the intermediate heat exchanger 1 expands in this way, the annular protrusion 1
9 can move downward within the movable cylindrical portion 16, so that its elongation can be easily absorbed.

In this embodiment, there is no need to attach a preheater and a heat insulating material to the portion of the intermediate heat exchanger 1 inserted into the container 13.

For this reason, when inspecting the welded parts on the outer surface of the container of the intermediate heat exchanger 1 during maintenance and inspection of the intermediate heat exchanger 1, the preheater and heat insulating material must be removed and installed within the narrow guard vessel as in the past. There is no need to do this.

Since the work involved in maintenance and inspection of the intermediate heat exchanger 1 is reduced, maintenance and inspection become easier.

In the part inserted into the container 13 of the intermediate heat exchanger 1,
Since a preheater and a heat insulating material are not required, the volume of the guard vessel 12 itself is reduced compared to that of the conventional guard vessel 5.
The volume can be smaller than its own volume.3 This increases the space between the equipment and piping, making it easier to install the equipment and piping.

Although the guard vessel for the intermediate heat exchanger has been described, similar effects can be obtained by applying this embodiment to the guard vessels for the reactor vessel, sodium pump, and piping.

An embodiment applied to the piping described above will be described based on FIG. 4.

Components that are the same as those in the embodiment shown in FIG. 2 are designated by the same reference numerals.

The primary cooling system piping 27 connects the reactor vessel, intermediate heat exchanger, sodium pump, and reactor vessel in this order.

A part of the primary cooling system piping 27 is U-shaped as shown in FIG.

The primary cooling system piping 27 of such a portion is arranged within the guard vessel 12 in the same manner as shown in FIG.

The guard vessel 12 includes a container 13 whose top is open and a lid 14 that covers the top of the container 13.

The container 13 is fixed to the floor surface 7. The preheater 8 is attached to the side surface of the container 13, and the heat insulating material 9 is attached to the container 13 so as to cover the preheater 8.

A drain pipe 10 is inserted into a space 20 formed between a pipe 27 and a container 13.

The lid 14 consists of a fixed ring part 15 fixed to the container 13 with bolts, and a pair of movable cylindrical parts 16A and 16B detachably attached to the fixed ring part 15.

The fixed ring part 15 and the movable cylindrical parts 16A and 16B are
It has a two-part structure.

Outside the container 13, similar to the intermediate heat exchanger shown in FIG.
A preheater 3 and a heat insulating material 18 are attached around the primary cooling system piping 2γ.

The movable cylindrical parts 16A and 16B are arranged above the fixed ring part 15 and around the primary cooling system piping 27.

A heat insulating material 1 is placed below the annular protrusion 1T of the movable cylindrical portion 16A.
8. There is an annular protrusion 19 at the lower end.

A similar structure exists between the movable cylindrical portion 16B and the heat insulating material 18.

The preheater 3 and the heat insulator 18 are not attached to the primary cooling system piping 27 inside the container 13 .

In this embodiment as well, the same functions and effects as in the embodiment shown in FIG. 2 can be obtained.

Another embodiment of the invention is shown in FIGS. 5 and 6.

FIG. 5 shows the annular protrusion 19 of the embodiment shown in FIG. 3 separated from the heat insulating material 18.

The annular protrusion 23 is attached to the intermediate heat exchanger 1 by welding, and is arranged between the fixed ring part 15 and the annular protrusion 17.

In the embodiment shown in FIG. 6, a lid 24 (corresponding to the fixing ring part 15) attached to the upper part of the container 13 is made to protrude close to the heat insulating material 18, and a guard vessel 25 is attached to the container 13.
and a lid 24.

An annular protrusion 26 is formed in the intermediate heat exchanger 1 below the lid 24 and reaches near the side wall of the container 13 .

These embodiments also provide the same effects as those of the embodiments described above.

According to the present invention, a heater attached to the outside of the guard vessel heats the part of equipment or piping inserted into the guard vessel that is filled with liquid metal, and heats that part between the equipment or piping and the guard vessel. This can be done by an annular gap with a cover on top and an insulating material attached to the outside of the guard vessel.

Therefore, according to the present invention, there is no need to attach a heater or a heat insulating material to the part of the equipment or piping inserted into the guard vessel, and maintenance and inspection of the equipment or piping can be easily performed at the part inserted into the guard vessel.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of a conventional guard vessel, Fig. 2 is a longitudinal sectional view of a heat insulating device for equipment which is a preferred embodiment of the present invention, and Fig. 3 is a detailed longitudinal sectional view of the section ■ in Fig. 2. Figure 4 is a vertical sectional view of a piping heat retention device according to another embodiment of the present invention, and Figure 5 is
6 and 6 are longitudinal cross-sectional views of other embodiments of the heat insulating device for equipment. Explanation of symbols, 1...Intermediate heat exchanger, 12...
... Guard vessel, 13 ... Container, 14.
・・・・・・Lid, 17°19・・・Annular protrusion, 2
1... Gap.

Claims (1)

[Claims] 1. A guard vessel into which a device or piping containing liquid metal is inserted from above, a first heater and a first heat insulating material attached to the outside of the guard vessel, and a device or pipe that is outside the guard vessel and into which the device or the pipe is inserted. A heat insulating device for equipment or piping, comprising a second heater and a second heat insulating material attached to the outside of the pipe, and a member covering an annular gap formed between the second heat insulating material and the container.