JPH046917B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention is used as a testing device for simulating core heat transfer and flow characteristics of a multi-purpose high-temperature gas reactor, for example, by transferring a heavy test object such as a block simulating a reactor core to a pressure vessel. The present invention relates to a support device for supporting without applying thermal stress.

Because there is a large temperature difference between the high-temperature test specimen and the pressure vessel that houses it, the above-mentioned support device is designed to suppress the thermal stress generated in the support device as much as possible, and to be used in the support device. It is desirable to minimize exposure of metal members to high-temperature gases.

Here, the head support device that was conventionally used is the first one.
As shown in the figure. Fig. 1 shows a device in which a fuel test body 2 simulating an actual reactor core is housed in a pressure vessel 1, and cooling gas is flowed from the outside in the direction of arrow A to test the heat transfer flow characteristics of the reactor core. It is. pressure vessel 1
It consists of an outer cylinder 3 and a header 4 made of a heat insulating material such as ceramic fiber placed above and below the outer cylinder 3. The test specimen 2 is a heavy object consisting of a graphite block 2, which is the same as the core of the actual reactor, with gas passage holes 5 installed therein, and a heater with the same heat generation capacity as the fuel. A heat insulating block 6 is interposed between the test specimen 2 and the outer cylinder 3 to surround the test specimen 2. 7 is a gas inlet and outlet piping to the pressure vessel. Such test specimen 2 and heat insulation block 6
The weight of the pressure vessel 1 is supported by the pressure vessel 1 via the following support device 8. That is, the support device 8 is constructed as an assembly of graphite support blocks 9, carbonaceous heat insulating blocks 10, and heat-resistant metal support cylinders 11 arranged one on top of the other in the radial direction. Among these, the support block 9 on which the test specimen 2 is directly placed and supported is made of graphite with high thermal conductivity in order to alleviate the thermal shock caused by the temperature change of the cooling gas. The heat insulating block 10 is designed to provide heat insulation between the metal support cylinder 11 and is made of a carbonaceous heat insulating material with low thermal conductivity.The weight load of the test specimen 2 is insulated from the support block 9. It is transmitted to the pressure vessel 1 via the block 10 and the support tube 11. Further, the support tube 11 is provided with an upper edge flange so as to support the heat insulation block 6 at the same time. Further, all of these members and the test specimen 2 are brought into surface contact to prevent the flow of the cooling gas bypassing through a path other than the gas passage hole of the test specimen.

By the way, in the above test equipment, the temperature inside the test body 2 is about 1000℃, while the temperature inside the pressure vessel 1 is about 1000℃.
Since the outer cylinder 3 is water-cooled to suppress temperature rise, a very large temperature difference occurs between the two, and the temperature gradient due to this temperature difference acts in the radial direction of the support device 8, causing the insulation block to 10, support tube 11
generate excessive thermal stress. That is, the heat insulating block 10 itself has a very large thickness in the radial direction, and the temperature gradient in the radial direction of the block itself becomes large. Furthermore, although the carbonaceous heat insulating block 10 in contact with the inner periphery of the support tube 11 has a relatively low thermal conductivity,
Thermal conductivity is one order of magnitude higher than that of a heat insulating material such as ceramic fiber, so the inner diameter side of the support tube becomes quite hot. On the other hand, the pressure vessel 1 is water-cooled as described above. Furthermore, each component is restrained in the radial direction, and as a result, excessive thermal stress is generated between the inner and outer diameters of the support cylinder flange and the heat insulating block 10 due to the temperature difference. Note that in order to alleviate the thermal stress, it is possible to consider a method such as making a slit in the flange portion of the support tube to release thermal expansion, but this method cannot be adopted from the viewpoint of preventing bypass of the gas flow.

It is an object of the present invention to eliminate the drawbacks of the above-mentioned conventional structure and to provide a device for supporting a heavy object that can be used in high-temperature gas with higher integrity.

The present invention will be described in detail below based on illustrated embodiments.

In FIG. 2, the support device 8 according to the present invention includes a support block 9 made of graphite, a heat insulating block 10 made of ceramic with low thermal conductivity, a cylindrical first support tube 11A made of heat-resistant metal, and an inverted truncated conical support tube 11A. and a second heat-resistant metal support tube 11B.
The heavy load is carried out by support block 9 and insulation block 1.
0, is supported by the pressure vessel 1 via the second support cylinder 11B and the first support cylinder 11A. In addition, heat insulation block 5
is supported in the same way. Here support block 9
is a cylindrical body with a gas flow path in the center, and supports the test specimen 2 on its flat upper surface. The heat insulating block 10 is a cylindrical body whose outer diameter is not so large as shown in the left, and engages with a step on the outer periphery of the support block 9 to support the support block 9 from below while covering the peripheral surface of the support block. . On the other hand, the first support cylinder 11A arranged along the inner circumference of the pressure vessel outer cylinder 3 has flanges on the upper and lower sides, and the lower flange is fixedly supported on the pressure vessel side. A second supporting cylinder 1 having an inverted truncated cone shape is formed by applying flanges at the upper and lower ends so as to span between the upper flange of the cylinder 11A and the lower surface of the heat insulating block 10.
1B is installed across the bridge. Furthermore, the remaining spaces on the inner diameter side of the heat insulating block 10 facing the high temperature gas flow path side and on the inner and outer diameter sides of the metal support tube 11B are covered with ceramic fibers having excellent heat insulation properties and made of the same material as the header 4 of the pressure vessel. There is.

According to the above configuration, first, the support block 9 and the inner diameter side flange of the second support cylinder 11B are located vertically opposite to each other, and the heat insulation block 10, which is interposed between them and performs heat insulation, has a wall thickness in the radial direction. Since it can be made thinner, thermal stress due to temperature differences in the radial direction is reduced accordingly. Also, since the inner diameter side is covered with another heat insulating material, it is not directly exposed to high temperature gas. However, a large temperature difference still occurs between the support part of the heat insulating block 10 and the part fixed to the pressure vessel 1.
By combining A and the inverted truncated conical second support cylinder 11B in series as shown in the figure, the temperature gradient in the radial direction is converted to the temperature gradient in the axial direction, so that deformation due to thermal expansion is Unlike the device shown in FIG. 1, it is no longer completely restrained and can escape relatively freely, so thermal stress is alleviated, and thus generation of excessive thermal stress can be avoided. In this configuration as well, all of the parts are in surface contact with each other as in the conventional structure, and it is possible to prevent the cooling gas flow from being improperly bypassed within the pressure vessel.

As described above, the present invention provides a heavy object support device that includes a support block that supports a heavy object, a heat insulating block that supports the support block, a cylindrical support cylinder whose lower flange is fixedly supported on the pressure vessel side, and a support block that supports a heavy object. It is constructed as a combination structure with an inverted truncated cone-shaped support tube installed between the upper flange of the support tube and the lower surface of the insulation block, and therefore, unlike conventional devices, each component that makes up the support device is Compared to a structure in which the pressure vessel and the pressure vessel are overlapped in the radial direction, the thermal stress generated in the support device due to the large temperature difference between the center part exposed to high-temperature gas and the pressure vessel can be significantly alleviated. This makes it possible to improve the soundness of the support device.

It should be noted that the present invention is not limited to the test apparatus shown as an example in the drawings, but can be broadly applied to various apparatuses that support heavy objects in high-temperature gas.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of the entire structure of a nuclear reactor core simulation test apparatus using a conventional support device, and FIG. 2 is a cross-sectional view of the structure of an embodiment of the present invention. 1... Pressure vessel, 2... Test specimen as a heavy object, 5... Gas flow path hole, 7... Gas flow path piping,
8...Support device, 9...Support block, 10...
Heat insulation block, 11A...first support cylinder, 11B
...Second support tube, A...Gas flow.

Claims (1)

[Scope of Claims] 1. A support structure for supporting a heavy object placed in a high-temperature gas flow path in a pressure vessel that houses it, which surrounds the high-temperature gas flow path and supports the heavy object on its upper surface. A support block made of a material with high thermal conductivity, a cylindrical heat insulation block that supports the support block, and a diameter larger than the heat insulation block,
and a cylindrical first metal support tube whose lower flange is fixedly supported on the pressure vessel side, and an upper flange of the cylindrical metal support tube and the insulation block so as to transmit the load of heavy objects to the support tube. 1. A support device for a heavy object installed in a high-temperature gas, characterized by comprising a second metal support tube in the shape of an inverted truncated cone, which is installed to span between the bottom surface and the bottom surface. 2. The support device according to claim 1, wherein the inner diameter side of the heat insulating block facing the high temperature gas flow path is covered with a heat insulating material having good heat insulation properties.A heavy object installed in a high temperature gas. support device.