JPS62233692A - Support structure of thermal shield plate for thermal shock prevention - Google Patents

Abstract

PURPOSE:To attempt abating thermal shock at a structure section of a larger wall thickness in a flow channel wall by mounting a thermal shield plate to the structure section of a larger wall thickness in a flow channel wall through an annular spacer and making a gap between the flow channel wall and the thermal shield plate a nonfluid area. CONSTITUTION:On the inner circumferential face of a structure section P of a large wall thickness in a flow channel wall 1 a thermal shield plate 9 is arranged to provide a gap S between the inner face of the wall and the plate 9 in order to abate heat shock due to high temperature fluid at the large wall thickness section. Annular spacers 20 are provided near the ends 30 and 31 of the upper and lower openings of the gap S respectively, and their inner and outer circumferential faces contact in metal touch with the outer circumferen tial face of the thermal shield plate and the outer circumferential face of the thermal shield board 9 and the outer circumferential face of the structure section of a large wall thickness, and the shield plate 9 is fixed to the outer cylinder by metal supports. High temperature fluid flowing through a high temperature fluid channel 3 is, therefore, prohibited to flow into the gap S by means of the spacers 20, and the gap becomes a nonfluid area, or a thermal shock buffer layer. Accordingly the temperature difference between the inner and outer walls a the large wall thickness section P becomes very small and stresses due to thermal shock are sufficiently abated.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a support structure for a thermal shielding plate for preventing thermal shock, and in particular to a support structure for a thermal shielding plate for preventing thermal shock. The present invention relates to a support structure for a heat shield plate that cushions impact.

[Conventional technology]

An example of a conventional support structure for a heat shield plate will be explained based on FIGS. 4 to 6.

FIG. 4 shows an example of a vertical shell-and-tube heat exchanger (intermediate heat exchanger) used in an atomic couplant, and in the figure, 1 is the outer shell of the heat exchanger.

2 is a primary fluid artificial nozzle, 3 is a primary fluid flow path, 4 is a heat exchange section that accommodates a heat exchanger tube bundle 5, 6 is a primary fluid outlet, 7 is a secondary fluid supply pipe, 8 is 2 This is a secondary fluid outlet, and the primary fluid (primary coolant) flows out from the primary fluid outlet 6 after being heat exchanged in the heat exchange section 4 . In such a heat exchanger, when an internal thermal transient phenomenon occurs due to a rapid temperature change in the primary fluid, etc., the outer wall temperature of the thick structure part P (structural discontinuity part) where the wall thickness at the outer periphery increases and A temperature difference occurs in the inner wall temperature, and thermal shock stress occurs in the thick wall structure P. In particular, large thermal shock stress is likely to occur in the heat exchanger of a fast breeder reactor that uses liquid sodium, which has high thermal conductivity. Ta. Therefore, a heat shielding plate 9 is conventionally attached to the inner wall of the thick structure part P of the heat exchanger to reduce thermal shock stress.

In addition to the conventional mounting example of the heat shield plate on the upper part of the external inner wall as shown in FIG.
There is one that is attached to the inner wall of a fluid nozzle as shown in Japanese Patent No. 36631, and heat shield plates are attached to various thick-walled structures.

FIG. 5 is a partially enlarged sectional view showing a conventional support structure for this type of heat shielding plate, and FIG. 6 is a view taken from the direction of arrow D in FIG. 5, as shown in these drawings.

Conventionally, a disk-shaped support fitting (spacer) 10 is attached to the inner circumferential surface 1a of the outer shell 1 by fillet welding (circumferential welding) 13, and a large number of support fittings 10 are arranged in the circumferential direction of the outer shell inner circumferential surface 1a. , a cylindrical heat shielding plate 9 is assembled into the protrusion 11 of the support fitting 10, and a presser plate 1 is attached to the protrusion 11 penetrating from the heat shielding plate 9.
The heat shield plate 9 was attached by fitting and fixing the heat shield plate 2.

[Problem that the invention seeks to solve]

Such a support structure for a heat shield plate has the following problems that should be improved.

That is, conventionally, the main body 10 of the support fitting 1o of the heat shielding plate 9
Since the F+ is formed into a disk shape and the fillet weld 13 is applied, an unwelded part occurs between the outer WR 1 and the metal fitting main body 10a. When the internal fluid temperature changes rapidly, an internal temperature difference will occur between the surface of the fitting body Ion that contacts the inner circumferential surface of the outer J511 and the surface that contacts the outer circumferential surface of the heat shield plate 9. As a result, thermal deformation (deflection) occurs in the metal fitting main body 10a.

There was a risk that an excessive thermal load would be applied to the welded part 13, impairing the function of the welded part 13, and eventually causing a problem in the function of supporting the heat shield plate. In addition, the support metal fitting 10 of the heat shield plate
are arranged on the inner circumferential surface of the outer shell 1 with a gap in the circumferential direction, so that part of the fluid passing through the flow path 3, as shown by the arrow X in FIGS. 5 and 6, It flowed into the gap S between the inner circumferential surface 1a of the outer shell 1 and the outer circumferential surface 9a of the heat shielding plate 9, and a flow region was generated in the gap. Therefore, in the event that the original function of the heat shield plate 9 is impaired and a sudden internal thermal transient occurs, the thermal shock cannot be sufficiently alleviated due to the lack of temperature followability of the thick internal structure P. There was also.

The present invention has been made in view of the above points, and its purpose is to ensure the soundness of a support member that supports a heat shield plate, and to provide reliability that can sufficiently alleviate thermal shock. The object of the present invention is to provide a support structure for a high heat shielding plate.

[Means for solving problems]

In order to achieve the above object, the present invention forms an annular spacer interposed between a thick-walled structure of a high-temperature fluid flow path and a heat shielding plate; The annular spacer is disposed at both ends of the opening of the gap between the inner circumferential surface of the wall and the outer circumferential surface of the heat shielding plate, and the outer circumferential surface of the annular spacer is placed on the inner circumferential surface of the thick structure. The inner circumferential surface of the spacer is brought into contact with the outer circumferential surface of the heat shielding plate to block the fluid in the high temperature fluid flow path from flowing into the gap between the thick structure part and the heat shielding plate, and the gap is A plurality of support fittings having a completely welded groove are welded to the installation position of the front 4D annular spacer on the inner circumferential surface of the channel wall and arranged in the circumferential direction to make the support metal a non-flow area. The heat shielding plate is supported by making a metal fitting protrude from an insertion hole provided in the annular spacer and fixing the heat shielding plate through the protruding portion.

[Effect]

According to the present invention having such a configuration, the annular spacer interposed between the inner circumferential surface of the channel wall and the outer circumferential surface of the heat shielding plate closes the gap between the thick structure and the heat shielding plate. This prevents fluid from flowing into the gap, and this gap becomes a non-flow area.
The fluid in the high-temperature fluid flow path does not come into direct contact with the inner circumferential surface of the IV wall structure.

As a result, a thermal buffering effect works in the gap, and even if the temperature of the high-temperature fluid changes rapidly, the temperature difference between the outer wall temperature and the inner wall temperature of the thick-walled structure becomes extremely small, reducing the thermal shock that occurs in the thick-walled structure. can be sufficiently relieved.

In addition, since the support metal fittings that support the heat shield plate are attached to the inner circumferential surface of the thick-walled structure by complete welding, there is no room for unwelded parts to occur at these welded locations as in the past.
As a result, even if humidity changes occur in the high-temperature fluid, there will be no places where thermal deformation occurs in the support metal fittings, which prevents excessive thermal loads from being applied to the welded parts of the support metal parts, and by extension the support metal Jl. be able to ensure the soundness of

〔Example〕

An embodiment of the present invention will be explained based on FIGS. 1(a), 1(b) to 3. FIG.

FIG. 1(a) is a partially omitted sectional view showing an embodiment of the heat shield plate support structure of the present invention, and FIG.
Figure 2 is an enlarged sectional view of the 11th cut (b) in the front direction (B
FIG. 3 is a partially cutaway sectional view seen from above (direction C) in FIG. 2.

First, the outline of the heat shield plate support structure of this embodiment will be explained based on FIG. 1(a). In the drawings, the same reference numerals as in the conventional example shown in FIGS. 4 to 6 indicate the same parts. That is, 1 is the medium rIrJ used for the atomic couplant.
The outer shell of the heat exchanger, 3 is the inner MJ of the outer J scrap 1 of the intermediate heat exchanger.
The flow path for the primary coolant (liquid sodium) is formed along IIN, and 9 is a heat-proofing heat source installed on the inner peripheral surface of the J'X flesh structure P of the primary fluid flow path 3. The heat shielding plate 9 is a shielding plate, and the heat shielding plate 9 is formed of a cylindrical thin metal plate, and is attached to the thick wall of the outer shell along the inner circumferential surface of the outer shell by a mounting member 21 with an annular spacer 20 (described later) interposed therebetween. It is attached to the structural part P.

The annular spacer 20 forms a gap S between the inner circumferential surface 1a of the thick structure part P and the outer circumferential surface 9a of the heat shielding plate 9. Each annular spacer 2o is arranged such that its outer circumferential surface contacts the inner circumferential surface 1a of the outer shell 1 with a metal touch, and the inner circumferential surface thereof contacts the outer circumferential surface 9a of the heat shielding plate 9 with a metal touch. It's Nishide.

FIG. 1(b) is an enlarged cross-sectional view of part A in FIG. 1(a) showing the details of the support structure of the heat shielding plate 9. In FIG. This is a mounting member for attaching to the inner circumferential surface of the meat structure P]a.

The mounting member 21 consists of a small-diameter cylindrical supporting metal fitting 22 and a disc-shaped pressing plate 23. The support fitting 22 has one end 22'
is sharpened into a conical shape to make the conical surface a completely welded groove surface, and a plurality of supporting metal fittings 22 are arranged in the circumferential direction at the mounting positions of the annular spacers 2o on the inner circumferential surface of the outer shell 1, and It is fixed by performing complete welding 24 with the tip of one end 22' in point contact with the inner circumferential surface 1a of the outer shell 1. On the other hand, the annular spacer 20 is inserted in the circumferential direction.
.

A plurality of holes 25 are provided, and when the annular spacer 2o is arranged on the inner peripheral surface of the outer shell 1, the support metal fitting 22 is inserted into the insertion hole 25, and a part of the support metal fitting 22 protrudes from the insertion hole 25. It is. Then, after inserting the protruding portion of the support fitting 22 protruding from the insertion hole 25 into the mounting hole 9b of the heat shielding plate 9, the holding plate 23 is fitted into the supporting fitting 22, and the holding plate 23 is inserted into the mounting hole 9b of the heat shielding plate 9.
3 is in contact with the inner peripheral surface of the heat shielding plate 9, and by welding 26 the holding plate 23 and the fill of the support fitting 22, the heat shielding plate 9 is attached while being pressed against the inner peripheral surface of the annular spacer 2o. ing. The insertion hole 25 provided in the annular spacer 20 is formed to have a diameter sufficiently larger than the diameter of the support fitting 22, so that when the annular spacer 20 thermally expands in the circumferential direction, the welded portion 24 of the support fitting 22 is inserted. This is to prevent shear load from being applied. Further, the annular spacer 20 includes
As shown in FIG. 3, in order to absorb circumferential elongation due to thermal expansion, a part of the annular spacer 20 is divided (a portion indicated by the symbol G) to form a gap 27 for absorbing thermal expansion. An uneven step surface 28 is formed on the end surface of each divided portion G of the annular spacer 20.
．． 29 is formed, and the uneven surfaces of the stepped surfaces 28 and 29 are overlapped and bonded to each other to prevent fluid from flowing between the joints of the divided portion G.

According to such a heat shielding plate support structure, a gap S is formed between the outer circumferential surface 9a of the heat shielding plate 9 and the inner circumferential surface 1a of the thick-walled component P via the upper and lower annular spacers 20. is formed, and each annular spacer 20 is formed on the inner circumferential surface 1a of the outer shell 1.
and the outer circumferential surface 9/1 of the heat shielding plate 9 along the circumferential direction with a metal touch, thus preventing fluid from flowing into the gap S via the annular spacer 2o. Therefore, the gap S
In this case, the primary high-temperature fluid flowing into the primary fluid flow path 3 does not flow and form a flow, and the gap S becomes a non-flow region (stagnant region).

The primary high temperature fluid does not come into direct contact with the inner circumferential surface 1a of the thick structure portion P, and the gap S forms a thermal buffer layer.

As a result, even if the temperature of the 51st-order high-temperature fluid changes suddenly, the fluid heat after the temperature change is not transferred to the knob wall structure part P immediately, but gradually over time, and during that time, the fluid heat after the temperature change is transferred to the thick wall structure part P. The entire wall thickness of the outer shell 1 is transferred from the thin wall structure P' other than the thick wall structure P' (the N wall structure P' is already in a state that follows the temperature change of the primary high temperature fluid). Since the humidity of the primary high-temperature fluid approaches the temperature of the primary high-temperature fluid due to the The temperature difference on the inner wall side becomes extremely small, and the heat generated in the thick structure part P? l
I impact stress can be sufficiently alleviated.

Furthermore, the support metal fittings 22 that support the heat shielding plate 9 are as follows.

Since it is attached to the inner wall of the outer shell 1 by complete welding 24, an unwelded part (the part indicated by the symbol a in FIG. 5) is generated between the outer shell 1 and the support fitting 22 as in the conventional case. As a result, there is no place where thermal deformation can occur in the support fitting 22 even if a sudden temperature change occurs in the primary high temperature fluid, so an excessive thermal load is applied to the welded part 24. It is possible to reliably prevent this and ensure the integrity of the welded portion 24.

Furthermore, according to this embodiment, the support fitting 22 that supports the heat shielding plate 9 fits into the holding plate 23 without protruding from it, and the joint surface d between the supporting fitting 22 and the holding plate 23 forms a flat surface. Because of this, the fluid resistance of the primary high-temperature fluid can be minimized.

The annular spacer 20 is formed with a divided part (gap part 27) that absorbs the elongation due to thermal expansion, and the insertion hole 25 in which the annular spacer 2o is disposed is made sufficiently large so that the shear load at the time of thermal expansion is absorbed by the support metal. 22, it is possible to provide a heat shielding plate support structure with excellent heat resistance and durability.

Note that this embodiment has been described using as an example the support structure of a heat shield plate attached to an intermediate heat exchanger of a nuclear couplant, but the structure is not limited to this, and other structures such as fast breeder reactors, pressurized watercolor reactors, etc. steam generator.

It can be applied to heat exchangers in thermal power plants, and also to high-temperature fluid containers, piping, etc. other than heat exchangers.

〔Effect of the invention〕

As described above, according to the present invention, the soundness of the support member that supports the heat shield plate is ensured, and the heat resistance is maintained. Therefore, it is possible to provide a highly reliable support structure for a heat shielding plate that can sufficiently reduce the impact caused by No. 11.

[Brief explanation of drawings]

FIG. 1(,) is a partially omitted cross-sectional view of a heat shielding plate support structure according to an embodiment of the present invention, and FIG. 1(b) is an A of FIG. 1(a).
FIG. 2 is a partially omitted front view of No. 11fi(b) as seen from direction B, FIG. 3 is a partially cutaway sectional view as seen from direction C of FIG. 2, and FIG. FIG. 5 is a cross-sectional view of a main part showing a conventional example of a heat shielding plate support structure, and FIG. 6 is a partially omitted cross-sectional view of the intermediate heat exchanger as viewed from direction D in FIG. ]... Outer shell (channel, 4!, la... inner peripheral surface of outer shell, 3... high temperature fluid flow path, 9... heat shielding plate, 9a...
・Outer peripheral surface of heat shielding plate, 20... annular spacer, 22・
...Supporting metal fitting, 23...Pressure plate, 24...Completely welded part, 25...Through hole, 27...Gap, 28.
29...Uneven stepped surface. 30.3.1... Both ends of the opening of the gap, G... Divided part, (and 1 other person) - 1st opening
υ. s-m main part Figure 2 Figure 30 4th review

Claims (1)

[Claims] 1. A heat shield plate is attached to the inner circumferential surface of a thick structure of a flow path wall forming a high temperature fluid flow path while maintaining a predetermined gap by interposing a spacer, The spacer is an annular spacer whose outer circumferential surface contacts the inner circumferential surface of the channel wall and whose inner circumferential surface contacts the outer circumferential surface of the heat shield plate, and the annular spacer is connected to the thick wall structure. are arranged at both ends of the opening of a gap formed between the inner circumferential surface of the heat shield plate and the outer circumferential surface of the heat shielding plate, and the fluid of the high-temperature fluid flow path is provided in the gap through the annular spacer. A supporting metal fitting having a full penetration groove is welded to the installation position of the annular spacer on the inner circumferential surface of the flow path wall. A plurality of supporting metal fittings are arranged in the circumferential direction, and the heat shielding plate is supported by protruding from an insertion hole provided in the annular spacer and fixing the heat shielding plate through the protruding portion. A support structure for a heat shield plate for preventing thermal shock, characterized by: 2. In claim 1, the annular spacer is divided into several parts, and each of the divided parts has a gap for absorbing elongation due to thermal expansion of the annular spacer, and the divided annular spacer has a structure The ends of the member have uneven stepped surfaces that overlap and join each other, and the insertion hole provided in the annular spacer is formed to such an extent that no shear load is applied to the support fitting during thermal expansion of the annular spacer. A support structure for a heat shield plate for preventing thermal shock, wherein the hole diameter is sufficiently larger than the outer diameter of the support fitting.