JPH033830Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a heat insulating structure for a high-temperature heat exchanger, and in particular, the present invention relates to a heat insulating structure for a high-temperature heat exchanger.
A heat insulating material is applied to the inner and outer walls to form a heat insulating layer on these, making it possible to create an internal and external heat retention structure, preventing the end plate from rising above a predetermined temperature, and preventing the temperature gradient of the end plate. This invention relates to a heat insulating structure for a high temperature heat exchanger that can reduce the size of the heat exchanger.

[Prior Art] In recent years, research and development has been carried out on multi-purpose high-temperature gas reactors that utilize the heat generated in nuclear reactors for multiple purposes such as power generation, steel manufacturing, chemical reactions, seawater desalination, and district heating and cooling. This multi-purpose high-temperature gas reactor extracts the heat generated in the reactor using a primary high-temperature heat medium such as helium, exchanges heat between the primary high-temperature heat medium and the secondary high-temperature heat medium through intermediate heat exchange, and uses a steam generator to exchange heat between the primary and secondary high-temperature heat medium. Next, heat is exchanged between the high temperature heat medium and the water supply system.

A high-temperature heat exchanger such as an intermediate heat exchanger for exchanging heat between primary helium gas and secondary helium gas has a configuration as shown in FIG. 4, for example.

As shown in the figure, the heat exchanger 1 has a cylindrical outer shell 2, and an outer shell insulation layer 3 is formed on the outer shell 2 to keep it warm.

This outer body heat insulating material layer 3 is formed to cover the outer side of the outer body 2 from the upper end plate part 4 forming the upper part to the lower end plate part 5 forming the lower part.

Further, the lower end plate portion 5 forming the lower part of the outer body 2 includes an outlet portion 7 for the primary helium gas A and an outlet portion 7 for the primary helium gas A.
An inlet section 6 is provided in a double structure inside.

The primary helium gas A introduced from the inlet 6 passes between the inner shell 8 and the manifold 9 and flows from the circulation outlet 10 to the circulation inlet 11 via a primary helium circulator (not shown). It's summery. The primary helium gas A flowing into the circulation inlet 11 passes between the outer shell 2 and the inner shell 8 and is circulated from the outlet 7 to the reactor.

Furthermore, an outlet section 12 and an inlet section 13 for the secondary helium gas B are formed in the upper part of the manifold 9 in a double structure. Secondary helium B is introduced into the inlet portion 13 via a secondary helium circulator (not shown), and this secondary helium gas B flows into the helical heat exchanger tube 14, where it is mixed with the primary helium gas. After exchanging heat with gas A, it is collected in a manifold 9 and circulated through an outlet section 12 to a steam generation section.

[Problems to be solved by the invention] By the way, as mentioned above, the primary helium A is forcibly circulated and cooled by the secondary helium system circulator, but the secondary helium system circulator does not control the driving of the primary helium A. In the event of an accident such as a stoppage, natural convection will occur due to temperature differences instead of cooling.

Due to this natural convection of primary helium gas A, the temperature gradually rises from the bottom of the outer shell 2 upwards, and in particular, the temperature of the upper end plate 4 forming the upper part of the outer shell 2 rises by about 100 degrees Celsius compared to during normal operation. As a result, there was a risk that the temperature of the upper end plate 4 would exceed its permissible temperature. Therefore, in the conventional external heat insulation structure, the upper end plate 4
The permissible temperature had to be increased, which necessitated a design change.

[Purpose of the invention] The present invention was created to effectively solve the problems mentioned above.

The purpose of this invention is to prevent the head plate forming one end of the outer shell of the heat exchanger from reaching a temperature higher than the permissible temperature when the circulation of high-temperature heat medium such as primary helium gas is stopped due to the stoppage of the circulator. An object of the present invention is to provide a heat insulating structure for a high-temperature heat exchanger, which can prevent temperature rise, reduce the temperature gradient of a head plate part, and improve the reliability of the heat exchanger.

[Summary of the invention] In order to achieve the above object, the present invention provides a heat-insulating structure for a high-temperature heat exchanger in which an outer-shell insulation material layer is formed on the outer side of the heat exchanger outer shell so as to cover it. An internal heat insulating material layer is formed along the inner wall of the end plate forming one end of the outer shell, and an external heat insulating layer thinner than the outer shell heat insulating material layer is formed along the outer side in order to reduce the temperature gradient in the end plate. The internal insulation layer prevents the temperature of the head plate from rising above a predetermined temperature in the event of an accident, and the external insulation layer prevents heat in the thickness direction of the head plate. This is designed to relieve bending stress due to stress or thermal expansion difference.

[Example] An example of the present invention will be described in detail below with reference to the accompanying drawings.

As shown in FIG. 1, an outer shell 2 formed in a cylindrical shape is provided, and a lower end plate 5 forming the lower part of the outer shell 2 has an outlet part 7 and an inlet part 6 for primary helium gas A. is provided with a double pipe structure.

The primary helium gas A introduced into the outer shell 2 from the inlet part 6 is normally passed between the inner shell 8 and the manifold 9, and then from the circulation outlet part 10 to the circulation inlet part 11 via a primary helium circulator (not shown). It is beginning to be introduced in The primary helium gas A introduced into the circulation inlet section 11 is normally circulated between the outer shell 2 and the inner shell 8 through the outlet section 7 to the reactor.

On the other hand, an inlet section 13 and an outlet section 12 for the secondary helium gas B are formed in the upper part of the manifold 9 in a double pipe structure. The secondary helium gas B is passed through the inlet section 13 through a secondary helium circulator (not shown).
is introduced from the manifold 9 and exchanges heat with the primary helium gas A in the helical heat exchanger tube 14.
After passing through, the steam is circulated through the outlet section 12 to the steam generator.

Further, an outer shell insulating material layer 3 is formed on the outer shell 2 to keep it warm. This outer shell insulation layer 3
is formed from the lower mirror plate part 5 to the upper part of the outer body 2 so as to cover the outer side thereof.

In particular, in the present invention, the upper end plate 4 of the outer body 2 is provided with an internal heat insulating layer 1 for keeping it warm.
5 is formed. This internal heat insulating material layer 15 is formed along the inner wall of the upper mirror plate portion 4 to a predetermined thickness (approximately 150 mm). This internal heat insulating material layer 15 is made of, for example, Kao wool.

Further, an external heat insulating material layer 16 is formed along the outer side of the upper mirror plate portion 4 . This external insulation layer 16
is formed to be continuous with the outer shell heat insulating material layer 3 covering the outer shell 2 and to have a thickness thinner than this. In this embodiment, the thickness is less than half the thickness of the outer shell insulation layer 3 (50~
The thickness of the external heat insulating material layer 16 is set to 60 mm). For example, the external insulation layer 1 is made of calcium silicate, etc.
6 is formed.

The external heat insulating layer 16 formed in this way is designed to reduce the temperature gradient of the upper end plate 4.

That is, as shown by the broken line in FIG. 2, the temperature gradient in the upper end plate 4 increases only with the internal heat insulating layer 15 formed on the inner wall of the upper end plate 4, but as shown by the solid line, By forming 16, the temperature gradient in the upper mirror plate portion 4 can be reduced.

This means that the local thermal stress generated in the thickness direction of the upper end plate portion 4 is alleviated.

Further, by forming the external heat insulating material layer 16 thinner than the outer body heat insulating material layer 2, the amount of heat dissipated from the upper end plate portion 4 is increased, and a rise in temperature of the upper end plate portion 4 is suppressed.

Furthermore, as shown in FIG.
5 and the outer shell insulation layer 3 alone, bending stress is created between them due to the difference in thermal expansion between the upper end plate portion 4 on the outer shell insulation layer 3 side and the upper end plate portion 4 on the inner insulation layer 15 side. occurs. That is, in response to the force that tends to extend the upper end plate 4 on the outer shell insulation layer 3 side, the upper end plate 4 on the inner insulation layer 15 side
can only grow within that temperature range, so
As shown by the broken line in the figure, a force is generated between them, and the outer shell 2 is deformed so as to bulge outward. The outer heat insulating material layer 16 is made of such an outer shell 2.
This alleviates the bending stress, that is, the force caused by the difference in thermal expansion of the outer shell 2, and prevents the outer shell 2 from deforming outward.

In this way, the present invention has an internal heat retention structure in which the internal heat insulating layer 15 is formed on the inner wall of the upper end plate 4, so that the upper end plate 4 can be prevented from rising above the allowable temperature in the event of an accident such as when the circulator stops driving. It is possible to prevent the temperature from rising and also to ensure the amount of heat dissipated from the upper end plate 4 by the external heat insulating layer 16 while alleviating the thermal stress or bending stress that occurs there, improving the reliability of the heat exchanger. can be done.

[Effects of the invention] In summary, according to the invention, an internal heat insulating layer is formed along the inner wall of the end plate forming one end of the outer body, and an external heat insulating layer is formed along the outer wall. In the event of an accident such as when the circulator stops driving, it is possible to prevent the temperature of the end plate from rising beyond its permissible temperature, thereby improving the reliability of the heat exchanger.

[Brief explanation of drawings]

Fig. 1 is a schematic side sectional view of a high-temperature heat exchanger according to the present invention, Fig. 2 shows the main parts of the present invention and shows the temperature gradient of the end plate, and Fig. 3 shows bending stress generated in the end plate. FIG. 4 is a side sectional view showing a conventional high temperature heat exchanger. In the figure, 2 is an outer shell, 3 is an outer shell heat insulating material layer, 4 and 5 are end plates, 15 is an inner heat insulating material layer, and 16 is an outer heat insulating material layer.

Claims (1)

[Scope of utility model registration request] In a high heat exchanger in which an outer shell insulation layer is formed to cover the outer part of the heat exchanger outer shell,
An internal heat insulating layer is formed along the inner wall of the head plate forming one end of the outer shell, and an outer layer is thinner than the outer shell heat insulating material layer in order to reduce the temperature gradient of the head plate along the outer side. A heat insulating structure for a high temperature heat exchanger characterized by forming a layer of heat insulating material.