JPS63180888A - Liquid metal cooling heat exchanger - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat exchanger for cooling liquid metal suitable for a heat exchanger that integrates a ring pump and a heat exchanger.

[Conventional technology]

As shown in Figure 2, the reactor cooling system for a loop-type liquid metal cooled fast breeder reactor includes a primary main circulation pump 3 disposed between a reactor vessel 1 and an intermediate heat exchanger 2. They are connected by piping 4. The primary coolant, which is a liquid metal, flows out of the reactor vessel 1, is pressurized by the primary main circulation pump 3, flows into the intermediate heat exchanger 2, exchanges heat with the secondary coolant, and then returns to the reactor. It flows into container 1. For the primary main piping 4, both the intermediate heat exchanger 2 and the primary main circulation pump 3 serve as one anchor point (fixed point), so the piping installed between commercial equipment must be meandered to absorb thermal expansion. Therefore, the disadvantage is that the length of the piping becomes long and the building containing them also becomes larger. A tank-type liquid metal cooled fast breeder reactor, in which the core and all primary cooling system equipment are housed in one large container, is also possible, but it is necessary to construct a very large reactor vessel. Therefore, I came up with the idea of simplifying the primary main piping 4 by integrating the intermediate heat exchanger 2 with the primary main circulation pump.

A conventional example of such a heat exchanger is JP-A-53-18.
As described in No. 850, a mechanical pump is placed in the center,
There are those in which a bundle of heat transfer tubes is arranged around the heat exchanger and housed in one container, and those in which an electromagnetic pump is inserted inside the heat exchanger as in Japanese Patent Application Laid-Open No. 61-794.

[Problems to be Solved by the Invention] Among the above-mentioned conventional techniques, in the case of incorporating a mechanical pump as in JP-A-53-18850, the outer diameter of the body becomes large and the internal structure of the heat exchanger becomes complicated. There is.

In addition, in cases where an electromagnetic pump is incorporated inside a heat exchanger as in JP-A-61-794, the structure is simpler than that in which a mechanical pump is incorporated, but the entire electromagnetic pump is immersed in high-temperature liquid sodium. When inspecting the electromagnetic coil of the electromagnetic pump, it is not possible to inspect it from the outside, so it is necessary to remove the seal and pull out the entire electromagnetic pump. In addition, the design of the electromagnetic pump part is difficult because the heat resistance and sodium resistance of the seal and coil for leading out the cable to the outside are strict.

An object of the present invention is to solve problems such as maintainability, heat resistance, and sodium resistance of an electromagnetic pump coil, and a seal for pulling out a cable to the outside in a heat exchanger integrated with an electromagnetic pump.

[Means for solving problems]

The above purpose is to install an annular core with an electromagnetic coil on the outside of the heat exchanger body, install only the annular core inside the body, and create a flow path for liquid metal between the electromagnetic coil and the core. This is achieved by creating a structure that produces a pump action.

[Function] In the heat exchanger according to the present invention, an iron core with an electromagnetic coil installed outside the body generates a magnetic field, which excites the iron core installed inside the body. The magnetic field and the Lorentz force generated by the current generated in the liquid metal in the flow path between the core and the shell act as a pump. Therefore, since the coil is installed outside the body, maintenance of the electromagnetic coil becomes easy, nine conditions for heat resistance design of the electromagnetic coil are relaxed, and there is no need to consider sodium resistance.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 8 shows a system in which the present invention is applied to an intermediate heat exchanger and a steam generator of a loop type fast breeder reactor, and
FIG. 9 shows a system in which the present invention is applied to a steam generator for a tank-type fast breeder reactor. Both include the amount of piping in the plant,
It is possible to reduce the installation space.

FIG. 1 shows the structure of the intermediate heat exchanger in FIG. 8.

The high temperature primary liquid metal is transferred from the inlet pipe 5 to the upper plenum 1.
2, flows through the heat transfer tube 9, exchanges heat with the secondary liquid metal outside the tube, becomes low temperature, and collects in the lower plenum 13, then flows between the annular core 14 and the outer shell 15, where it It is pressurized by the Lorentz force generated from the magnetic field of the electromagnetic coiled iron core 10 and the induced current generated in the primary sodium, and returns from the outlet pipe 6 to the reactor vessel 1 shown in FIG. 8.

The low temperature secondary liquid metal flows into the inlet pipe 7 and enters the central pipe 1.
After lowering 1 and reversing it, go up the outside of the heat exchanger tube 9, and 1
After exchanging heat with the next liquid metal and reaching a high temperature, it is guided from the outlet pipe 8 to the steam generator 31 shown in FIG.

The electromagnetic pump includes an annular iron core with an electromagnetic coil (hereinafter abbreviated as an electromagnetic coil) 10 provided in the heat exchanger outer shell 15, and an annular iron core 14 provided inside the container opposite to the electromagnetic coil 1o.
The structure is such that a coolant flow path is formed between the electromagnetic coil 10 and the iron core 14.

The electromagnetic pump used in the present invention is a linear induction type.

This includes FLIP (Flat Linear Ind
(cution pump) type and ALIP (Annular
There is a Linear Induction (Pun+p) type. Electromagnetic pumps drive liquid metal using a magnetic field generated by an electromagnetic coil and a Lorentz force caused by an induced current, but because the depth of penetration of the magnetic field into the liquid metal is determined, the width of the flow path is limited.

Therefore, the FLIP type is not suitable for creating a large flow passage cross-sectional area due to its shape, and the ALIP type is used for a large capacity type.

There are two types of ALIP types: one in which only an iron core is installed inside the flow path, and one in which an iron core with an electromagnetic coil is installed. Types in which an iron core with an electromagnetic coil is installed inside the flow path can be made smaller because the penetration depth of the magnetic field is greater, but the electromagnetic coil is immersed in high-temperature liquid metal, which poses problems in terms of maintainability and heat resistance. becomes.

On the other hand, the type with only the iron core inside is 1000 (M W
When applied to the main cooling system (4 loops) of a class e) fast breeder reactor, it is difficult to install it on piping because the diameter of the flow path must be extremely large, about 4 (m). However, if the structure of the present invention is such that the electromagnetic coil 1o is provided in the outer shell of the heat exchanger and the iron core 14 is provided in the inner cylinder of the container, it will fit well, and there will be problems with the maintainability and heat resistance and sodium resistance of the electromagnetic coil 10. It can be eliminated.

In addition, since the electromagnetic coil 10 weighs approximately 50 tons, an electromagnetic coil support structure 18 is provided separately from the heat exchanger main body support structure 17.
Supported by A gap is provided between the electromagnetic coil 10 and the outer shell 15, and the difference in thermal expansion between the heat exchanger body and the electromagnetic coil is absorbed by sliding.

FIG. 3 shows the structure of the steam generator of the present invention shown in FIGS. 5 and 6.

The secondary liquid metal flowing in from the inlet pipe 7 flows down around the helical coil heat transfer tube 27, exchanges heat with the water in the tube, and becomes low temperature. When flowing between the annular iron core 14 and the outer shell 15, it is pressurized by the Lorentz force generated from the magnetic field and induced current generated by the electromagnetic coil 10, rises up the central tube 11, and flows through the outlet piping 8 to the intermediate heat exchanger 2. return.

Next, water flows in from the water supply inlet 26 and rises inside the helical coil heat transfer tube 27, exchanges heat with the secondary liquid metal, becomes high-temperature steam, and flows out from the steam outlet 25.

FIG. 7 shows a main cooling system when the present invention is applied to an intermediate heat exchanger/steam generator integrated heat exchanger in a loop type fast breeder reactor.

FIG. 4 shows the structure of the above intermediate heat exchanger/steam generator integrated heat exchanger.

The high temperature primary liquid metal is transferred from the inlet pipe 5 to the upper plenum 1.
2, flows down inside the heat transfer tube 9, exchanges heat with the secondary liquid metal around the tube, becomes low temperature, and collects in the lower plenum 13, then ascends the central tube 11 and flows through the outlet pipe 6 into the reactor vessel 1. be returned to.

Next, the secondary liquid metal exists in a sealed state in the container of the heat exchanger, and the Lorentz force is generated between the annular core 14 and the outer shell 15 from the magnetic field and induced current caused by the annular electromagnetic coil 1o. The heat transfer tube 9 is pressurized and rises around the heat transfer tube 9 while receiving heat from the high temperature primary liquid metal inside the tube. Thereafter, the water flows down through the helical coil heat transfer tube 27 while imparting heat to the water.

The water flowing in from the water supply pipe 26 is transferred to the coiled coil heat exchanger tube 2
7, during which it exchanges heat with the high temperature secondary liquid metal around the tube and becomes vapor. Thereafter, the steam flows from the steam outlet 25 to the turbine 33.

Further, a cover gas region 30 is provided in the upper part to absorb volume changes due to temperature of the secondary liquid metal.

〔Effect of the invention〕

According to the present invention, the maintainability and heat resistance of the electromagnetic coil in an electromagnetic pump integrated with a heat exchanger are improved, and there is no need to consider sodium resistance, so a more rational and easy design can be achieved. Since the seal for leading the cable to the outside is removed, the overall reliability is also increased.

Furthermore, as a plant, there is no need for piping between the pump and the heat exchanger, and the installation space is reduced, which has the effect of making the building that houses them more compact.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of an embodiment of the present invention, FIG. 2 is a diagram of a conventional loop-type fast breeder reactor main cooling system, and FIG.
4 is a vertical sectional view showing other embodiments of the present invention, FIG. 5 is a loop diagram to which the present invention is applied, and FIG.
FIG. 7 shows a loop in which the present invention is also applied to a steam generator. 5... Primary system inlet piping, 6... Primary system outlet piping, 7
...Secondary system inlet piping, 8...Secondary system outlet piping, 9.
...Heat transfer tube, 10...Electromagnetic pump coil, 11...
Central pipe, 12... Upper plenum, 13... Lower plenum, 14... Annular core, 15... Outer shell, 16...
・Inner cylinder.

Claims (1)

[Claims] 1. A heat exchanger consisting of a container and a bundle of heat transfer tubes inside the container and having a heat exchange function between liquid metal and liquid metal or liquid metal and non-liquid metal, in which an annular electromagnetic pump is provided around the outer periphery of the container. An iron core with an electromagnetic coil is provided, and an annular electromagnetic coil-free core is provided inside the container opposite to the electromagnetic coil to form a flow path for liquid metal coolant between the electromagnetic coil-equipped iron core and the electromagnetic coil-free core. A heat exchanger for liquid metal cooling characterized by: 2. The heat exchanger has a structure in which the core with the outer electromagnetic coil is supported separately from the heat exchanger body, and a gap is provided between the heat exchanger and the core with the outer electromagnetic coil to release thermal expansion of the heat exchanger body. A heat exchanger for liquid metal cooling according to claim 1. 3. In a heat exchanger in which heat exchange between liquids is performed in the shell, and at least one of the liquid metals is a liquid metal, the heat exchanger is arranged so as to surround the first flow path of the liquid metal leading to the heat exchange area in the shell. an iron core without an electromagnetic coil provided at a position to form a flow path of the liquid metal as shown in FIG. It is characterized by comprising: an iron core with an electromagnetic coil provided at a position above the iron core without an electromagnetic coil; and an inversion flow path for the liquid metal that flows through both the first and second flow paths in the shell below the iron core without an electromagnetic coil. A heat exchanger for liquid metal cooling.