JPS616498A - Radiation preventive structure of high-temperature multiple piping - 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 In the present invention, in internally insulated high-temperature multiple piping for transporting high-temperature fluid, discontinuous portions of the heat insulating material in the support structure supporting the liner container constituting the flow path of the high-temperature fluid are provided. Regarding the structure that blocks radiant heat leakage 1, is the insulation performance? This invention relates to an improved radiation prevention structure for high-temperature multiple piping.

High-temperature piping that transports high-temperature fluids, such as primary fluid i/X in a multipurpose high-temperature gas reactor, which is a type of nuclear blunt.
100OC1a With high-temperature, high-pressure fluids reaching OKV/crAl, piping materials that can withstand such high temperatures and pressures for long periods of time are currently under development. Therefore, piping that transports such fluids must maintain the pressure within the system. A structure that separates the pressure boundary and temperature barrier is currently being adopted for this purpose. That is, the basic structure of high-temperature piping is as shown in FIG. 1, in which a pressure pipe 1 for maintaining the pressure of high-temperature fluid 4 and a liner 3 for forming a flow path for the fluid 4 are arranged concentrically to form an annular shape. An internal insulation method is adopted in which an annular portion is formed and a heat insulating material 2 is filled in the annular portion.1. ing.

〃) In such a structure, the insulation material is discontinuous at the installation part of the spacer for maintaining the space between the pressure pipe 1 and the liner 3, and the support structure that supports the liner 3. Gaps formed in the insulation material at discontinuities caused heat leakage due to radiation, which not only increased heat loss but also became the main cause of hot fist spots.

Next, as a countermeasure to this problem, fibrous heat insulating materials such as Ceramic 9 Fiber were filled with increased packing density to prevent the occurrence of gaps.

However, as the temperature of the fluid used gradually rises, the insulation layer is divided into two layers, and the low temperature side is Insulation materials with a relatively long life at high temperatures, such as molded insulation materials such as metal laminated insulation materials, are increasingly being used for the high-temperature side Vr-. . Therefore, gaps are likely to occur at discontinuous portions of the heat insulating material, which poses a problem in preventing leakage of radiant heat.

The present invention was developed in view of the above-mentioned technical problems, and it prevents radiant heat from leaking from the pipe, suppresses the occurrence of spots and heat leakage, improves the insulation performance, and uses a locally discontinuous structure. The object of the present invention is to provide a radiation prevention structure for high-temperature multiple piping that makes it possible to reduce the generated thermal stress.

That is, the present invention includes a liner that constitutes a flow path for high-temperature fluid in high-temperature multiple piping. In the gap space between both sides of the support structure to be supported and the heat insulating material placed outside the liner pipe, a radiant plate having a short reflection plate concentrically and multiplexed integrally is installed, and the radiant heat of the high temperature fluid ρλ is absorbed by the gap. By blocking leakage through the space to the pressure pipe side, it prevents local overheating of the pipe due to radiation heat transfer and reduces the occurrence of thermal stress in the support structure, thereby maintaining the integrity of the pipe. It is characterized by an increase in sex.

An embodiment of the present invention will be described in detail below.

FIG. 2 shows an example of internally insulated high-temperature multiple piping, where 5 is a pressure pipe and 6 is a liner for forming a flow path for the innermost high-temperature fluid 7 (for example, He gas). This liner 6
A heat insulating layer is provided between the pressure pipe 5 and the partition pipe 8.
It is divided into two layers through interposition, and the inside is covered with, for example, a metal laminated insulation material 9.
10?Fibrous insulation material on the outside? Filling 0 partition pipe 9
is integrally formed with a partition pipe support 1lk having a truncated conical shape f' at one end thereof, and the other end is attached to the male power pipe 5 by welding. The liner 6 is fixed to the pressure pipe 5 via a liner sabot 12'. Liner Sabo) 12 is a deformed cone-shaped structure with a tubular part in the center,
One end is fixed in contact with the liner 6 and the other end is in contact with the partition pipe 8. As shown in FIG. 3, 13 reflective roots are provided between the liner sabot 12 and the metal laminated heat insulating material 9. Figure m4 is a 18-person diagram of the radiation reflecting plate 13, in which reflective pieces 13a' that reflect radiation are provided in multiple layers on the thin disc-shaped plate 13, and the tips of the reflecting pieces i" 3 a (7) are It may have a flat shape as shown in the figure, or it may be bent inward as shown in Fig. The slide joint portion 14 is provided in the structure shown in FIG.
0 C,, I Kp/crAP pressure tube 5 and 1000
Since the metal temperature difference between the liner 6 and the liner 6 that is in contact with the gas at ℃, 40b/a/lP reaches as much as 900C, the difference in thermal expansion will be absorbed by the slide joint part 14.
Because a pressure loss occurs in the fluid between the slide joint 14 and the next slide joint, a pressure difference is generated, so that high-temperature fluid 7 is generated in the metal laminated insulation material between the slide joints. However, the insulation performance will be drastically reduced.

However, the liner support 12 installed between the partition pipe 8 and the liner 6 not only has the function of branching the liner 6 into the partition pipe 8, but also has a sealing function to block short-path flow. Therefore, there is no short bath flow, and no deterioration in insulation performance occurs. That is, the radiation prevention plates 13 installed on both sides of the liner support 120, or the gap created between the metal laminated heat insulating material 9 and the liner support 12.
High temperature fluid of 100C, 40Kt/cat7
Does it reflect the incoming radiant heat that is generated and leak to the partition pipe 8 side? Since the liner support 5 and the partition pipe 8 are isolated from each other, there is no overheating of the liner support 5 and the partition pipe 8, and therefore the generated thermal stress is reduced.
As described in detail above, the radiation prevention structure of the present invention is a support for supporting the liner assembly that constitutes the flow path of high-temperature fluid in high-temperature multiple piping. 11) Overheating of the liner support structure can be prevented by installing radiant heat reflecting plates on both sides of the structure.
, reducing the occurrence of thermal stress in the structure; 1. It is possible to provide highly safe high-temperature multiple piping and will greatly contribute to the development of the nuclear power industry.

[Brief explanation of drawings]

Figure 1 shows the basic structure of high-temperature piping, and Figure 2 shows the structure of high-temperature multiple piping according to the present invention. The cross-sectional view shown in Figure 3 is an enlarged view of the radiation reflector mounting part, and Figure 4 is an example of the structure of the radiation reflector. FIG. 5 is a partial cross-sectional view showing another example of the structure of the radiation reflecting plate. 5... Pressure pipe 6... Liner 7... High temperature fluid 8... Partition pipe 9... Metal laminated insulation material 1
0...Fibrous insulation material 11...Partition pipe support 1
2... Liner support 13... Radiation reflector 1
3 a - Reflector piece 14...Slide joint Fig. 1 Fig. 2

Claims (1)

[Claims] A radiation prevention system that has short reflecting pieces concentrically integrated in the gap between both sides of the support structure that supports the liner that constitutes the flow path of high-temperature fluid in the high-temperature multiple piping and the insulation material placed on the outside of the liner pipe. A radiation prevention structure for high-temperature multiple piping characterized by the provision of plates.