JP2804805B2 - Furnace structure wheels - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wheel of a reactor internal structure, and more particularly to a wheel of a reactor internal structure suitable for moving a reactor internal structure of a fusion reactor. It is.

2. Description of the Related Art Since a fusion reactor generally handles high-temperature plasma, the inner wall of the reactor is damaged by high-energy radiation generated by the plasma and the fusion reaction, and is gradually worn away. Therefore,
Furnace structures such as divertors, inboards and outboards need to be replaced depending on the degree of wear. Since these furnace internal structures are heavy, it is necessary to provide wheels so that they can be easily moved.

An example of such a device is a diverter module transfer device disclosed in Japanese Patent Application Laid-Open No. 58-55879.

[Problems to be Solved by the Invention] As a result of a nuclear reaction in a nuclear fusion reactor, the reactor internals generate nuclear heat. For this reason, it is necessary to cool all the furnace internals during the furnace operation. Normally, the furnace internals perform water cooling, but the wheels rotate so that piping cannot be performed, and forced cooling with all liquids including water is impossible.

During operation of the furnace, the inside of the furnace is in a vacuum, so that cooling by air convection or heat transfer cannot be performed. Furthermore, since the wheel has a gap between the wheel and the axle, heat transfer by contact cannot be expected.
Therefore, the temperature of the wheel becomes high, causing problems such as deterioration and seizure.

The present invention has been made in order to solve the above-mentioned problems of the prior art, and does not hinder the rotation of the wheels during the movement of the furnace internals, and effectively cools the temperature rise due to the nuclear heating of the wheels even in a vacuum. It is an object of the present invention to provide a wheel of a furnace internals capable of being operated.

[Means for Solving the Problems] In order to achieve the above object, the most basic configuration of the wheel of the in-furnace structure according to the present invention includes an axle attached to the in-furnace structure having cooling means built therein. And a wheel fitted to the axle, wherein the material forming the wheel is a material having a smaller linear expansion coefficient than the material forming the axle.

Further, other configurations of the wheel of the furnace internals according to the present invention,
In a device comprising an axle and wheels attached to a furnace internal structure containing cooling means, a material forming the wheels is made of a material having a smaller linear expansion coefficient than a material forming the axles, and the axle and the wheels are A metal bearing formed of a material having a linear expansion coefficient substantially equal to the linear expansion coefficient of the material of the axle is press-fitted into the axle.

In order to further achieve the above object, the configuration of the third invention according to the wheel of the in-furnace structure of the present invention includes an axle attached to the in-furnace structure having a built-in cooling means, and fitted to the axle. A wheel having a larger coefficient of linear expansion than the material of the wheel, and the inner wall side of a hole through which the axle of the wheel passes is formed to be thin.

Further, the configuration of the fourth invention relating to the wheel of the in-furnace structure of the present invention is such that a concave bearing is formed in the in-furnace structure incorporating cooling means, and a spherical wheel is fitted to the concave bearing. And wherein the coefficient of linear expansion of the material of the spherical wheel is larger than the coefficient of linear expansion of the material of the concave bearing.

[Operation] The operation of each of the above technical means is as follows.

When the temperature of the furnace internals rises due to nuclear heating during furnace operation, the temperature of both the wheel and the axle rises, but due to the difference in linear expansion coefficient, the outer diameter of the axle becomes larger than the diameter of the hole in the wheel. . Therefore, the hole of the wheel and the axle come into close contact with each other, so that the heat of the wheel is transmitted to the axle side and is absorbed by the water-cooled furnace internal structure.

In addition, in the case where the material with a larger linear expansion coefficient than the material of the wheel is sealed inside the wheel and the inner wall side of the hole through which the axle passes has a thin structure, when the temperature of the wheel of the furnace internal structure rises due to nuclear heating. Since the material having a large coefficient of linear expansion thermally expands and the thin portion is deformed and comes into close contact with the axle,
The heat of the wheels is transmitted to the axle side and absorbed by the water-cooled furnace internals.

Furthermore, in the case of a spherical wheel whose bearing is located outside the wheel, if the material on the spherical wheel side has a larger linear expansion coefficient than that of the bearing side, when the temperature of the furnace internal structure rises due to nuclear heat, the spherical wheel Comes into close contact with the bearing (concave bearing) of the furnace internal structure, so that the heat of the spherical wheel is absorbed by the water-cooled furnace internal structure.

Embodiments Embodiments of the present invention will be described below with reference to FIGS. 1 to 4.

FIG. 1 is a sectional view showing a configuration of a wheel of a furnace internal structure according to one embodiment of the present invention.

In FIG. 1, reference numeral 1 indicated by a dashed line indicates a furnace internal structure 2.
An inverted T-shaped guide groove formed in a structure adjacent to
Is a furnace internal structure divided into a large number of modules, for example, which is closely arranged around the plasma region (not shown) of the nuclear fusion reactor. A water channel 8 is built in and is configured to be water-coolable.

In the example of FIG. 1, the wheels fit into the guide grooves 1 and are used to guide the in-furnace structure 2 to the destination. The present invention can also be applied to guide wheels for smoothly moving the furnace internal structure along the same principle based on the same principle.

The water-cooled internal structure 2 has an axle 3, a wheel 4 is fitted on the nuclear axle 3, a washer 5 and a nut 6.
Has been stopped by. A metal bearing 7 is mounted between the axle 3 and the wheel 4 in close contact with the axle 3, and a slight gap is provided between the metal bearing 7 and the axle 4. Can rotate with respect to the axle 3 and the metal bearing 7.

The bearing 3 and the metal bearing 7 are made of a material having substantially the same coefficient of linear expansion, and the wheel is made of a material having a smaller coefficient of linear expansion. For example, the axle 3 is made of stainless steel (SUS304), the metal bearing is made of a material made of copper and adsorbed with carbon, and the wheels are made of titanium. SUS304,
The coefficients of linear expansion of copper and titanium are 16.7 × 10 ^{-6 /} ° C and 17.7, respectively.
× a 10 ^-6 /℃,8.5×10 ^-6 / ℃. Here, since the difference in linear expansion coefficient between SUS304 and copper is small, if the metal bearing is pressed into the axle, the SUS304 and the metal bearing are in close contact even if the temperature rises.

Now, assuming that the temperature rise was, for example, 100 ° C. due to nuclear heating, the difference between the linear expansion coefficients of SUS304 and titanium was 8.2 × 1.
0 ^-6 / ° C, the difference in expansion at a temperature rise of 100 ° C is 8.4
× 10 ^-4 .

Therefore, the gap between the metal bearing and the wheel is 8.2 × 10
If the value is smaller than the value obtained by multiplying the axle diameter by ^-4 , the air gap disappears when the temperature rises within 100 ° C, and even in a vacuum, the heat generated at the wheels by heat transfer is transmitted to the structure through the metal bearings and the axle, and the cooling water passage 8 with water cooling.

When the furnace is stopped to stop nuclear heat generation and the temperature decreases, a gap is formed again between the metal bearing 7 and the wheel 4, so that the wheel 4 can rotate when moving the furnace internals.

That is, according to the present invention, when the temperature rises due to nuclear heating, the wheel comes into close contact with the metal bearing press-fitted into the axle, so that it can be efficiently cooled even in a vacuum.

Next, FIG. 2 is a sectional view showing a configuration of a spherical wheel of a furnace internal structure according to another embodiment of the present invention.

The embodiment shown in FIG. 2 shows a spherical wheel for two-dimensionally moving the internal structure of a nuclear fusion reactor, for example.

The in-furnace structure 9 is formed with a spherical concave portion that functions as a concave bearing, and has a coolant channel 13 related to the cooling means provided therein.

The spherical wheel 10 is fitted into the spherical concave portion of the furnace internal structure 9, and the fall prevention ring 11 is screwed into the spherical wheel 10.
10 is prevented from coming off the spherical recess.

On the inner surface of the spherical recess in contact with the spherical wheel 10, the rotation of the spherical wheel 10 is facilitated by using, for example, a static pressure bearing 12 as shown in the figure or a lubricating means (not shown).

Now, for example, it is assumed that stainless steel SUS304 is used for the furnace internal structure 9 and the falling-off prevention ring 11, and duralumin having a larger linear expansion coefficient than SUS304 is used for the spherical wheel. SUS3
Since the coefficient of linear expansion of 04 is 16.7 × 10 ^-6 / ° C and the coefficient of linear expansion of duralumin is 27.3 × 10 ^-6 / ° C, when the temperature rises due to nuclear heating during furnace operation, the outer diameter of the spherical wheel 10 Since the thermal expansion is larger than the diameter of the concave portion, it finally comes into close contact. For this reason, even in a vacuum, the heat of the spherical wheel 10 is absorbed by the furnace internal structure main body 9 by heat transfer, and is further discharged by the coolant flowing through the coolant passage 13 provided in the furnace internal structure body 9. .

Next, FIG. 3 is a cross-sectional view showing a configuration of a wheel of an in-furnace structure according to still another embodiment of the present invention, and FIG. 4 is a diagram showing deformation of the wheel shown in FIG. 3 when the temperature rises. It is a fragmentary sectional view.

In the embodiment shown in FIG. 3, a roller 15 is rotatably mounted on the in-furnace structure 9 using an axle 14, and a coolant passage 16 is provided in the axle 14 and the in-furnace structure 9. Forced cooling. The axle 14 is seal welded to prevent coolant leakage. The lateral movement of the roller 15 is restricted by the retaining ring 17.

Inside the roller 15, the material of the roller 15, for example, SUS304
A material having a larger linear expansion coefficient, for example, sodium 18 is sealed therein, and the shaft hole side of the sodium 18 sealing portion of the roller 15 is formed thin so as to be easily deformed.

Now, when the temperature rises due to nuclear heating during furnace operation, the linear expansion coefficient of sodium is 71 × 10 ⁻⁶ / ° C., which is much larger than the linear expansion coefficient of SUS304 of 16.7 × 10 ⁻⁶ / ° C. Swell. When melted, the volume increases by 2.7%. Therefore, as the temperature of the roller 15 rises, the volume of the sodium 18 thermally expands, the thin portion deforms as shown in FIG. 4, and the axle 14 and the roller 15 come into close contact with each other. The heat is absorbed by the axle 14 by heat conduction.

It should be noted that the present invention is not limited to the embodiments shown in FIGS. 1, 2 and 3 above. For example, a sodium-filled roller as shown in FIG. Needless to say, the same effects as those of the embodiment of FIG. 3 may be obtained by enclosing sodium in the furnace internal structure in the embodiment of FIG.

[Effects of the Invention] As described above in detail, according to the present invention, the rotation of the wheels during the movement of the furnace internals cannot be prevented, and the temperature rise due to the nuclear heat generation of the wheels can be effectively cooled even in a vacuum. Can be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a configuration of a wheel of a furnace internal structure according to one embodiment of the present invention, and FIG. 2 is a diagram showing a configuration of a spherical wheel of a furnace internal structure according to another embodiment of the present invention. FIG. 3 is a sectional view showing a configuration of a wheel of an in-furnace structure according to still another embodiment of the present invention, and FIG. 4 is a diagram showing a deformation of the wheel shown in FIG. 3 when the temperature rises. It is principal part sectional drawing. 2,9… Inner structure, 3… Axle, 4… Wheel, 7…
Metal bearing, 8 ... Cooling water channel, 10 ... Spherical wheel, 12 ...
Static pressure bearing, 13,16 …… Coolant flow path, 14 …… Axle, 1
5 ... Laura, 18 ... Sodium.

Continued on the front page (72) Inventor Kiyoshi Shibanuma 801 Nakahara, Naka-cho, Naka-machi, Naka-gun, Ibaraki Pref. Inside the Japan Atomic Energy Research Institute (72) Inventor Hideyuki Takatsu 801 Nakahara, Naka-cho, Naka-cho, Naka-gun, Ibaraki 1. Naka Atomic Energy Research Institute, Japan Atomic Energy Research Institute (58) Field surveyed (Int. Cl. ⁶ , DB name) G21B 1/00

Claims (6)

(57) [Claims] An axle attached to a furnace internal structure containing cooling means, and a wheel fitted to the axle, wherein the material forming the wheel is linearly expanded from the material forming the axle. Wheels for furnace internals characterized by using a material having a small coefficient. 2. An axle and wheels mounted on an internal structure of a furnace containing cooling means, wherein the material forming the wheels is a material having a smaller linear expansion coefficient than the material forming the axles. A wheel having a linear expansion coefficient substantially equal to a linear expansion coefficient of a material of the axle, and a metal bearing formed by press-fitting the axle between the wheel and the wheel. . 3. An axle attached to an internal structure of a furnace containing cooling means, and a wheel fitted to the axle. A wheel for an in-furnace structure, wherein a large material is enclosed and an inner wall side of a hole through which the axle of the wheel passes is formed to be thin. 4. The wheel of the furnace internal structure according to claim 1, wherein the wheel is the wheel according to claim 3. 5. A concave bearing is formed in an internal structure of a furnace containing cooling means, and a spherical wheel is fitted to the concave bearing, and a coefficient of linear expansion of a material of the spherical wheel is equal to that of the concave bearing. Wheels for furnace internals characterized by having a coefficient of linear expansion greater than that of the material. 6. The wheel according to claim 5, wherein the concave bearing is filled with a material having a higher linear expansion coefficient than the concave bearing, and the concave inner surface is formed to be thin.