JPS61112893A - Argon gas-filled molding heat-insulating material - Google Patents

Abstract

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

Description

[Detailed description of the invention] <Industrial field of application> The disclosed technology belongs to the field of structural technology for heat insulating materials attached to the outside of each equipment such as a nuclear reactor or piping in a fast breeder reactor nuclear power plant. .

Therefore, the invention of this application relates to a sealed metal integrally molded heat insulating material that is internally equipped with removable mirror insulation having a heat insulating function and is used in nuclear power plants, etc. Made of Gold B - This invention relates to a molded heat insulating material in which argon gas is sealed together with the mirror insulation, and a heat insulating material such as non-combustible wool or other fibers is included.

<Prior art> For example, a heat insulating material for a nuclear reactor or piping for flowing a coolant such as liquid metal sodium between the nuclear reactor and an intermediate heat exchanger has a structure that simply has a heat insulating function. Not only is this strictly required, but also from a safety point of view, it is required to be able to be easily attached and detached to expose each piece of equipment for periodic and irregular inspections.

For example, in light water reactors and the like, unit type molded heat insulating materials are assembled into blocks.

This type focuses on the radiation blocking function as a heat dissipation control method, so for example, a metal reflector is attached inside a sealed metal case made of stainless steel or the like to create a so-called mirror insulator. The reflective mirror blocks thermal radiation and also suppresses heat dissipation due to convection.

<Problems to be solved by the invention> Although heat insulating materials using metal boxes with interior mirror insulation have the advantages of being easy to attach and remove and retaining their thermal insulation properties, they have the following problems in high-temperature fast reactors, etc. There is a problem like this.

In plants that operate at high temperatures, such as fast breeder reactors, the reflective mirrors that form the mirror insulation are made of metal, which causes material changes such as discoloration, which impairs reflective performance. This may cause the insulation function of the heat insulating material to deteriorate.

Moreover, as a result, the capacity of cooling devices such as air conditioners and ventilation for the entire plant increases, which not only increases equipment costs but also makes maintenance and inspection difficult.

In addition, the heat insulating materials for such closed metal bodies such as fast breeder reactors, which have actually been improved and used, have the disadvantage of being large and heavy, and having poor workability during attachment and detachment.

To deal with this, it may be possible to make the metal box more completely sealed to maintain the internal vacuum, but this would not only be expensive in terms of equipment, but would also make it difficult to maintain the internal vacuum. The disadvantage is that it does not necessarily provide sufficient reliability in terms of guarantees.

The purpose of the invention of this application is to solve the technical problem of insulation of nuclear power plant equipment based on the above-mentioned prior art.

<Means/effects for solving the problem> In order to solve the above-mentioned problem, the structure of the invention of this application, which is based on the scope of the above-mentioned patent claims, is based on the above-mentioned purpose. A removable heat insulating material that is installed on the outside of high-temperature generating equipment such as a breeder reactor. A predetermined metal box is sealed in advance as □, and mirror insulation is installed inside it.
Furthermore, argon gas was hermetically sealed to prevent changes in the material of the reflecting mirror of the mirror insulation and to maintain the function of preventing heat dissipation due to radiation over time.

Furthermore, a fibrous heat insulating material such as non-combustible wool is installed inside the mirror insulation, thereby not only preventing the reduction in radiation of the mirror insulation but also directing convection of the mirror insulation to the fibrous heat insulating material. The function of the heat insulating material can be maintained sufficiently over time.

If the enclosed argon gas is activated, it has a short half-life, so it can be dealt with within the waiting time for the radiation to decay during maintenance.

In this way, by using a heat insulating material that is easy to put on and take off, and has better heat retention performance and aging performance than conventional ones, it becomes easier to use surrounding air conditioning equipment, ventilation equipment, etc., and the power required is reduced.

<Embodiment - Configuration - Function> Next, one embodiment of the present invention will be described below based on the drawings.

In the embodiment shown in FIG. 1, reference numeral 1 is a heat insulating material for nuclear power plant equipment, which constitutes the gist of the invention of this application. It is detachably installed on the outer surface of the pipe 6.

In the case of a plurality of leak detectors, the configuration is as shown in FIG. 2, but since it is not directly related to this invention, the attachment/detachment mechanism of the leak detector etc. is omitted.

Further, the embodiment shown in FIG. 3 shows a plurality of joints connected in the circumferential direction and in the longitudinal direction.

Needless to say, the heat insulating material 1.1' of the invention of this application is not limited to a fan-shaped cross section according to the shape of the outer surface of each device.
Of course, any shape having a three-dimensional curved surface, such as a rectangular shape or a rhombus shape, can of course be adopted in terms of design.

Also, the internal mirror insulation is substantially the same as that of a light water reactor.

However, in the invention of this application, although it is impossible to illustrate, argon gas sealed as an inert gas inside the housing type casing 3 of the closed metal box is used during fast breeder reactor operation. It is sealed so that the atmospheric pressure is slightly higher than atmospheric pressure when it is in operation, and is approximately equal to the atmospheric pressure around the device, for example, about 1 atmosphere, which is expected to be slightly lower when it is stopped.

In addition, the inside of the casing 3 is filled with non-combustible wool 5.
Mirror insulation 4 is installed in between.

Argon gas is inherently more viscous than air or nitrogen, making it difficult for internal argon gas convection to occur.

Furthermore, since the mirror insulation 4 is in argon gas, it is difficult to change over time and dissipation due to heat radiation is prevented.

Furthermore, since the thermal conductivity of the enclosed argon gas is less than 10% lower than that of air or nitrogen, heat dissipation due to thermal conduction of the argon gas, which has less convection, is also reduced.

Recent experiments in fast reactors and the like have predicted that the nonflammable wool 5 will at least reduce gas convection.

Since the half-life of argon gas (1.83 hr) is short, for example, if the metal case as a heat insulator is sufficiently attenuated within the waiting time for cooling liquid metal sodium to be removed from the equipment. Even if there is activation in the event of a leak, the waiting time for the coolant to decay during maintenance is sufficient to deal with it.

<Effects of the Invention> As described above, according to the invention of this application, insulation of high-temperature plants such as fast breeder reactors is basically required, and it is possible to use heat insulating materials for periodic and irregular maintenance inspections. In a heat insulating material that must be attached and removed, it has the basically excellent effect of providing a heat insulating material that is light in weight and easy to attach and detach, with little exposure to radiation.

In addition, the insulation function of each heat insulating material does not change in any way over time and can be fully guaranteed, preventing convection within the body, and has the excellent effect of reducing tacitness, etc., and has a large energy saving effect. It is also possible to reduce air conditioning equipment in nuclear power plants.

[Brief explanation of drawings]

The drawings are detailed explanatory diagrams of the invention of this application, in which Fig. 1 is a perspective view of a basic embodiment of the heat insulating material, Fig. 2 is a perspective view of each metal box unit, and Fig. 3 is a perspective view of each unit. FIG. 4 is a partially broken perspective view of each unit made of metal; FIG. 5 is a partial sectional view of the molded heat insulating material attached to the outer surface of the equipment; The figure is a partial sectional view of the molded heat insulating material attached to the equipment, and FIG. 7 is a partial perspective view of another embodiment of the molded heat insulating material added to the equipment. 6., 6'... Equipment, 4... Mirror insulation, 1'... Metal box, 1... Molded heat insulating material, 5
...Insulation material

Claims (2)

[Claims] (1) In a molded heat insulating material of a sealed metal box that is removably installed on the outside of equipment such as a fast breeder reactor nuclear power plant and has mirror insulation inside, argon gas is sealed inside the sealed metal box. A molded heat insulating material containing argon gas. (2) In a molded heat insulating material for a sealed metal box that is removably attached to the outside of equipment such as a fast breeder reactor nuclear couplant and has mirror insulation inside, argon gas is inside the sealed metal box. A molded heat insulating material containing argon gas, characterized in that it is encapsulated and filled with a heat insulating material.