JP2010066211A - Support structure for plasma equilibrium magnetic field coil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a support structure for a plasma equilibrium magnetic field coil (EF coil) for dispersedly applying a fastening force to the plasma equilibrium magnetic field coil. <P>SOLUTION: The support structure for the EF coil 2 for a nuclear fusion apparatus includes a pair of clamps 31, 33 disposed to clip the EF coil 2, and the fastening force is applied to extension sections of the clamps 31, 33 extended to both sides of the EF coil 2 to clamp the EF coil 2 to support the EF coil 2 in relation to a toroidal magnetic field coil. A pair of pressure alleviating plates 4, which are disposed between the clamps 31, 33 and the EF coil 2, are interposed between the two extension sections of the clamps 31, 33. The pressure alleviating plate 4 includes a cross-section of a gradually decreasing thickness toward both ends of the extension sections of the clamps 31, 33 in the extension direction from a heavy thickness section having the greatest thickness. The pressure alleviating plate 4 is interposed with a flat face oriented to the EF coil 2 side and an inclined face oriented to the clamp 31, 33 side. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  In the present invention, a pair of clamps are arranged with a plasma equilibrium magnetic field coil (EF coil) for a fusion device interposed therebetween, and a clamping force is applied to the extension part of each clamp to the side of the plasma equilibrium magnetic field coil. The present invention relates to a support structure of a plasma equilibrium magnetic field coil that sandwiches a plasma equilibrium magnetic field coil and supports the plasma equilibrium magnetic field coil with respect to a toroidal magnetic field coil (TF coil).

  A support structure for this kind of plasma equilibrium magnetic field coil is disclosed in Patent Document 1 below. In Patent Document 1, a holder for holding an EF coil is fixed to a support seat provided on the TF coil. The holder is configured by suspending a clamp portion from a support structure fixed to a holder fixing surface of a support seat via a pair of leaf springs. The clamp is supported by sandwiching the EF coil by tightening the receiving plate connected to each leaf spring and the clamping plate connected to the receiving plate with clamping bolts in the direction in which the clamping bolts approach each other. is doing.

JP 2003-156582 A

  In the support structure described in Patent Document 1, the receiving plate and the clamping plate to which a clamping force is applied to the left and right end portions extending to the left and right sides of the EF coil are bent upward in the left and right central portions. Therefore, when mechanical pressure is concentrated on the left and right ends of the EF coil and vibration or the like is applied to the pressure concentrated portion to cause rubbing, there is a possibility that insulation deterioration may occur.

  An object of the present invention is to provide a support structure for a plasma equilibrium magnetic field coil that can be dispersed with respect to an EF coil and applied with a tightening force.

In order to solve such a problem, the plasma equilibrium magnetic field coil support structure of the present invention has a pair of clamps sandwiched between plasma equilibrium magnetic field coils for a fusion apparatus, and the plasma equilibrium magnetic field coils of each of the clamps. A support structure of a plasma equilibrium magnetic field coil that supports the plasma equilibrium magnetic field coil with respect to a toroidal magnetic field coil by applying a clamping force to the extending portions on both sides of the A pair of pressure relief plates disposed between the extended portions and interposed between each of the clamps and the plasma equilibrium magnetic field coil, wherein the pressure relief plate has the thickest wall portion To the both ends in the extending direction of the extending portion of the clamp, and has a cross-sectional shape in which one main surface is inclined to gradually reduce the thickness, and the other flat main surface is flattened with the plasma balanced magnetism. Toward the coil side, said one main surface, characterized in that it is interposed toward the clamping side.
Further, according to the present invention, the one principal surface of the pressure relaxation plate is curved in the same manner as a contact surface to the one principal surface of the clamp that has been given a predetermined clamping force and bent toward the plasma equilibrium magnetic field coil side. It is characterized by being inclined.
Further, the present invention is characterized in that the thick portion of the pressure relief plate is provided at a central portion of the pressure relief plate facing a central portion between both the extended portions of the clamp.

  According to the present invention, since the pair of pressure relief plates interposed between the clamp and the plasma equilibrium magnetic field coil receive the curved clamp over a wide range of inclined surfaces, it is distributed to the plasma equilibrium magnetic field coil. Tightening force can be applied.

  Hereinafter, the best mode of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of a TF coil (toroidal magnetic field coil) 1 included in the fusion device of the present embodiment. In addition, each direction of the up-down, front-back, left-right used in the following description is shown in each figure used for description. The top, bottom, front, back, left and right are described for explanation, and of course may be different from the actual arrangement.

  In the fusion device, a TF coil 1 having a D-shaped outer shape shown in FIG. 1 is arranged in an annular shape at equal intervals on the outer periphery of a center solenoid (not shown) that has a cylindrical shape and extends vertically. A plurality of (six in this embodiment) EF coils (plasma equilibrium magnetic field coils) 2 having an annular shape are supported on the support seats 12a to 12f of each TF coil 1 by the clamp device 3, respectively. .

  The TF coil 1 is configured by accommodating a wire made of a superconducting material such as NbTi, Nb3Sn, Nb3Al in a case. The EF coil 2 is formed by containing a superconducting material such as NbTi in stainless steel, and the outer periphery is covered with an insulating material. The TF coil 1 and the EF coil 2 are used to confine plasma in an annular vacuum vessel (not shown) that is disposed inside each TF coil 1 and extends along the circumferential direction of the center solenoid.

  As an example of a support structure of the EF coil 2 to the support seats 12a to 12f using the clamp device 3, a support structure to the support seat 12f will be described. FIG. 2 is a perspective view showing the external appearance of the clamping device 3.

  As shown in FIG. 2, the clamp device 3 that supports the EF coil 2 on the support seat 12 f connects the clamps 31 and 33 that sandwich the EF coil 2 in the vertical direction, and the clamp 31 and the clamp 33. And 33, a tension rod 34 for applying a tightening force for sandwiching the EF coil 2 and a pair of support leaf springs 32 for supporting the clamp 31 on each support seat 12f.

  The clamp 33 has a substantially rectangular flat plate shape, and an extension plate 331 extends from the front edge portion and the rear edge portion, respectively. The extending plate 331 extends in the front-rear direction from the lower ends of the front and rear side surfaces of the clamp 33, and has a cross-sectional shape in which the lower surface coincides with the lower surface of the clamp 33 and the upper surface is inclined downward toward the tip side to gradually become thinner. Have.

  Each extension plate 331 has left and right edges of the upper surface of the EF coil 2 sandwiched between the lower surface of the clamp 33 from the front extension plate 331 to the rear extension plate 331 of the clamp 33 (on the upper surface of the EF coil 2). The inner edge and the outer edge) have a planar shape that faces the left and right edges.

  A plurality of (four in the example shown in the figure) insertion holes 332 are linearly arranged at equal intervals in the front-rear direction at both left and right ends of the clamp 33. Each of the left and right insertion holes 332 is arranged so that the front and rear positions thereof are aligned with the insertion holes 332 at the opposite edges, and has an expanded portion at the upper end.

  The clamp 31 has a substantially rectangular flat plate shape having a wider left and right width than the clamp 33, and the extension plate 311 extending from the front and rear edges and the insertion through which the tension rod 34 is inserted in the same manner as the clamp 33. Hole 312. The insertion hole 312 extends with an equal diameter from the upper end to the lower end. Support leaf springs 32 are respectively fixed to the left and right ends of the clamp 31 positioned outside the insertion hole 312.

  The support plate spring 32 is a flat plate spring portion 322 extending in the vertical direction with the main surface facing left and right, and a substantially square block-like shape provided in both the upper and lower ends of the plate spring portion 322 and extending in the front-rear direction. And a fixed portion 321. A through hole 323 that penetrates the leaf spring portion 322 in the front-rear direction extends in a straight line from the upper end portion to the lower end portion of the leaf spring portion 322 at the center portion in the left-right direction on both front and rear sides of the leaf spring portion 322. is doing. The lower fixing portion 321 of the support plate spring 32 is fixed to the left and right ends of the clamp 31, and the upper fixing portion 321 is fixed to the support seat 12f.

  The tension rod 34 has a round bar shape with enlarged diameter portions at both upper and lower ends. The upper enlarged diameter portion has a head portion 34a, and the lower enlarged diameter portion has a male screw portion 34b. ing. The tension rod 34 is inserted into the insertion hole 312 and the insertion hole 332 through the upper and lower diameter expansion portions, the head 34 a is accommodated in the expansion portion of the insertion hole 332, and extends from the lower end opening of the insertion hole 312. A nut 35 (see FIG. 3) is screwed onto the male threaded portion 34b, and the clamp 31 and the clamp 33 are connected.

  FIG. 3 is a diagram for explaining a support method for sandwiching and supporting the EF coil 2 with the clamps 31 and 33. 4A and 4B are views showing the pressure relaxation plate 4 used when the EF coil 2 is sandwiched between the clamps 31 and 33. FIG. 4A is a perspective view, FIG. 4B is a plan view, and FIG. 4C is a plan view of FIG. It is a BB sectional view. FIG. 5 is a view for explaining the cross-sectional shape of the pressure relaxation plate 4.

  As shown in FIG. 3, the clamps 31 and 33 support the EF coil 2 by sandwiching the EF coil 2 in the vertical direction via the pressure relaxation plate 4. The pressure relaxation plate 4 interposed between the clamps 31 and 33 and the EF coil 2 will be described.

  As shown in FIG. 4, the pressure relaxation plate 4 interposed between the clamp 33 and the EF coil 2 is formed on the extension plate 331 on the rear end side from the front edge of the extension plate 331 on the front end side of the clamp 33. It is a flat plate having a planar shape substantially equal to the upper surface shape of the EF coil 2 toward the rear edge, and is formed of the same material as the clamp 33. The pressure relief plate 4 is provided with a thickest portion at the center in the left and right width direction, and is inclined by retreating the upper surface downward from the thick portion to the left and right ends, and gradually becomes thinner. It has a cross-sectional shape.

In the present embodiment, the upper surface of the pressure relaxation plate 4 is a cross section of the lower surface in which the clamp 33 to which a tightening force is applied from the tension rod 34 is bent using the contact portion with the thick portion of the pressure relaxation plate 4 as a fulcrum. It has a cross-sectional shape that matches the shape and is curved and inclined. Specifically, as shown in FIG. 5, the upper surface of the thick portion of the pressure relaxation plate 4 is the origin 0, and the axis extending through the origin 0 and parallel to the lower surface of the pressure relaxation plate 4 is the X axis. The amount of retreat (distance) δ toward the lower surface of the upper surface relative to is determined so as to satisfy the relationship expressed by the following (Equation 1).
δ = W (3Lx ² −x ³ ) / (6EI) (Formula 1)
Here, W: tightening force applied from the tension rod 34 to the clamp 33, L: distance on the X axis from the origin 0 of the position where the tightening force is applied to the clamp 33, x: upper surface of the pressure relief plate 4 On the X axis from the origin 0, E: Young's modulus of the clamp 33, and I: sectional moment of the clamp 33 at the distance x. In FIG. 5, the left-side cross-sectional shape from the thick part of the pressure relaxation plate 4 is described, but the left-side cross-sectional shape is also determined under the same conditions as the right side.

  Further, the pressure relaxation plate 4 interposed between the clamp 31 and the EF coil 2 includes the EF coil 2 extending from the front edge of the extension plate 311 on the front side of the clamp 31 to the rear edge of the extension plate 311 on the rear side. The lower surface from the thick part located in the center part of the left-right width direction to both ends is interposed between the clamp 33 and the EF coil 2 described above. A cross-sectional shape determined under the same conditions as the upper surface of the pressure relaxation plate 4 is formed.

  Next, operation | movement of the clamp apparatus 3 which clamps the EF coil 2 using the pressure relaxation board 4 is demonstrated using FIG.

  As shown in FIG. 6A, when a nut 35 is screwed onto the male threaded portion 34b of the tension rod 34 protruding downward from the clamp 31, the clamps 31 and 33 have a head 34a and A tightening force in a direction in which the nuts 35 approach each other is applied. When the clamps 31 and 33 to which the tightening force is applied from the head 34a of the tension rod 34 and the nut 35 sandwich the EF coil 2 in the vertical direction via the pressure relaxation plate 4, as shown in FIG. The left and right ends are bent in the direction in which the tightening force is applied, with the contact point with the thick portion of the pressure relaxation plate 4 as a fulcrum.

  The amount of tightening of the nut 35 with respect to the male threaded portion 34b of the tension rod 34 is a gap between the EF coil 2, the clamps 31 and 33, and the pressure relief plate 4 due to cooling and vertical electromagnetic force load during operation of the EF coil 2. When a predetermined tightening amount that can prevent the occurrence of the pressure is reached, the clamps 31 and 33 are curved and inclined upper surfaces of the pressure relaxation plate 4 that face the upper and lower surfaces that sandwich the EF coil 2 via the pressure relaxation plate 4. Or bend along the lower surface. As a result, the clamps 31 and 33 bent with the thick portion of the pressure relaxation plate 4 as a fulcrum bring the contact surface into close contact with the substantially entire surface from the left end to the right end of the upper surface or the lower surface of the pressure relaxation plate 4 in contact.

  According to the present embodiment, the pair of pressure relief plates 4 having a cross-sectional shape that gradually decreases in thickness from the thick part to the left and right ends, the flat surface faces the EF coil 2 side, and the inclined surface is clamped. By interposing between the clamps 31 and 33 and the EF coil 2 toward the sides 31 and 33, the contact surfaces of the clamps 31 and 33 with the pressure relief plate 4 are made thicker portions of the pressure relief plate 4. Can be bent along the shape of the inclined surface of the pressure relaxation plate 4. Therefore, the surface pressure can be distributed and applied not only to the left and right ends of the EF coil 2 but also to the center, and the maximum value of the surface pressure applied to the EF coil 2 can be kept small.

  Further, according to the present embodiment, the inclined surface of the pressure relaxation plate 4 facing the clamps 31 and 33 is a gap between the EF coil 2, the clamps 31 and 33, and the pressure relaxation plate 4 due to the operation of the EF coil 2. Since the surface of the EF coil 2 is curved and inclined equally to the contact surface to the inclined surfaces of the clamps 31 and 33 which are bent by applying a clamping force sufficient to prevent the occurrence of The pressure can be distributed more effectively.

  Examples of the present invention will be described below. FIG. 7 is a diagram showing the distribution in the left-right width direction of the surface pressure applied to the upper and lower surfaces of the EF coil 2 sandwiched between the clamps 31 and 33. FIG. 8 is a diagram showing a comparison between the cross-sectional shape of the pressure relaxation plate 4 and the maximum surface pressure applied to the upper and lower surfaces of the EF coil 2.

  First, when the clamping force is applied to the clamps 31 and 33 and the EF coil 2 is sandwiched, the pressure relaxation plate 4 is interposed between the clamps 31 and 33 and the EF coil 2, and the pressure relaxation plate 4 In comparison with the comparative example in which the EF coil 2 is directly sandwiched between the clamps 31 and 33 without interposing the wire, the distribution of the surface pressure applied to the upper and lower surfaces of the EF coil 2 in the left and right width directions is determined using the finite element method. Analyzed. The analysis results are shown in FIG.

  As shown in FIG. 7, in the comparative example in which the EF coil 2 is directly sandwiched between the clamps 31 and 33, a large surface pressure is applied to both left and right ends of the EF coil 2, and almost no pressure is applied to the center in the left and right direction. It can be confirmed that there is not. On the other hand, in the embodiment in which the pressure relaxation plate 4 is interposed, the surface pressure is distributed between the left and right ends of the EF coil 2, and the surface pressure as large as the comparative example is applied to the left and right ends. Can be confirmed.

  Thus, by inserting the pressure relief plate 4 between the clamps 31 and 33 and the EF coil 2 and sandwiching the EF coil 2, the EF coil 2 can be compared with the case where the clamp 31 and 33 directly sandwich the EF coil 2. It was confirmed that the surface pressure was dispersed between the left and right ends of 2, and the maximum surface pressure applied to the left and right ends could be kept small.

  Next, the relationship between the cross-sectional shape of the contact surface of the pressure relaxation plate 4 with the clamps 31 and 33 and the maximum surface pressure applied to the EF coil 2 was analyzed using a finite element method. For the analysis, as shown in FIG. 8A, the pressure relaxation plate 40a in which the cross-sectional shape of the contact surface with the clamps 31 and 33 from the origin toward the X-axis direction is formed flat, and curved surfaces 1 to 4 The pressure relaxation plates 40b to 40e formed in the above were used. The analysis result is shown in FIG.

  As shown in FIG. 8 (b), the pressure relief plate 40a having a flat contact surface with the clamps 31 and 33 has the largest maximum surface pressure of the EF coil 2 and the left and right widths of the thick portion gradually narrow. The maximum surface pressure is reduced in the order of 1 to 3 and the maximum surface pressure is the lowest on the curved surface 3 in which the inclined surfaces are curved and inclined in the same manner as the contact surfaces of the clamps 31 and 33 which are bent by the tightening force. I can confirm that. Further, it can be confirmed that the maximum surface pressure is larger in the curved surface 4 in which the inclined surface is curved and inclined more greatly than the contact surfaces of the clamps 31 and 33 which are bent by the tightening force.

  In this way, by bringing the cross-sectional shape of the pressure relaxation plate 4 closer to the cross-sectional shape of the contact surfaces of the clamps 31 and 33 that are bent by the tightening force, the surface pressure is applied between the left and right ends of the EF coil 2. It was confirmed that the maximum surface pressure applied to the EF coil 2 can be kept small by effectively dispersing. Moreover, it has confirmed that such an effect could be obtained more effectively by making the inclined surface of the pressure relaxation plate 4 bend and bend in the same manner as the contact surfaces of the clamps 31 and 33 bent toward the EF coil 2 side.

  In the said embodiment, the case where the retreating amount (distance) to the flat surface side of the inclined surface with which the pressure relaxation board 4 was provided was defined so that the relationship represented by (Formula 1) might be satisfy | filled. However, the pressure relaxation plate 4 has a cross-sectional shape in which the contact surface with the clamps 31 and 33 is inclined from the thickest portion having the greatest thickness to the left and right ends, and the thickness is gradually reduced. If the flat surface is oriented toward the EF coil 2 and the inclined surface is oriented toward the clamps 31 and 33, the cross-sectional shape of the inclined surface is arbitrary.

  For example, in the above-described example, in addition to the relationship defined in (Equation 1), the cooling force of the EF coil 2 and the like, the vertical electromagnetic force load generated in the EF coil 2 and the like are considered as necessary, and the tightening force And the inclined surface can be curved and inclined in the same manner as the contact surfaces of the clamps 31 and 33 which are bent toward the EF coil 2 side.

  Moreover, although the said embodiment demonstrated the case where the thick part of the pressure relaxation board 4 was provided in the center part of the left-right direction, the formation position of a thick part is not restricted to a center part, Arbitrary right-and-left direction is arbitrary. Can be determined at any position.

  Although the case where the pressure relaxation plate 4 is formed of the same material as that of the clamps 31 and 33 has been described in the above embodiment, the material of the pressure relaxation plate 4 is not necessarily the same as that of the clamps 31 and 33. You may form with a different material. In this case, it is possible to avoid concentration of surface pressure by curving and inclining the inclined surface of the pressure relaxation plate 4 so as to suppress the gap generated by the thermal contraction difference between the clamps 31 and 33 and the pressure relaxation plate 4.

  In the above embodiment, the case where the insertion holes 312 and 332 formed at the left and right ends of the clamps 31 and 33 are linearly arranged at equal intervals in the front-rear direction has been described. However, as shown in FIG. 9, the insertion holes 312 and 332 may be arranged along the left and right edges of the upper surface or the lower surface of the EF coil 2 held between the clamps 31 and 33.

It is a perspective view of TF coil with which the fusion device of one embodiment of the present invention is provided. It is a perspective view which shows the external appearance of the clamp apparatus with which a nuclear fusion apparatus is provided. It is a figure explaining the support method which inserts | pinches and supports an EF coil with a clamp. It is a figure which shows the pressure relaxation board used when pinching an EF coil with a clamp. It is a figure explaining the cross-sectional shape of a pressure relaxation board. It is a figure explaining operation | movement of the clamp apparatus which pinches | interposes an EF coil using a pressure relaxation board. It is a figure which shows distribution in the width direction on either side of the surface pressure added to the upper and lower surfaces of the EF coil inserted | pinched by the clamp. It is a figure which compares and shows the cross-sectional shape of a pressure relaxation board, and the maximum surface pressure added to the upper and lower surfaces of an EF coil. It is a figure explaining the modification of the arrangement | positioning method of the insertion hole with which a clamp is equipped.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 TF coil 12a-12f Support seat 2 EF coil 3 Clamp apparatus 31, 33 Clamp 312, 332 Insertion hole 32 Support leaf | plate spring 34 Tension rod 4 Pressure relief plate

Claims (3)

A pair of clamps are arranged with a plasma equilibrium magnetic field coil for a fusion device interposed therebetween, and a clamping force is applied to an extension portion of each of the clamps on both sides of the plasma equilibrium magnetic field coil, thereby the plasma equilibrium magnetic field coil Is a support structure of a plasma equilibrium magnetic field coil that supports the plasma equilibrium magnetic field coil with respect to a toroidal magnetic field coil,
A pair of pressure relief plates disposed between the extended portions of each of the clamps and interposed between each of the clamps and the plasma equilibrium magnetic field coil;
The pressure relief plate has a cross-sectional shape in which one main surface is inclined from the thickest portion having the largest thickness to both ends in the extending direction of the extending portion of the clamp to gradually reduce the thickness. A support structure for a plasma equilibrium magnetic field coil, wherein the other main surface is flat and faces the plasma equilibrium magnetic field coil side, and the one main surface faces the clamp side.   The one principal surface of the pressure relaxation plate is curved and inclined equally with a contact surface to the one principal surface of the clamp that has been given a predetermined tightening force and bent toward the plasma equilibrium magnetic field coil side. The support structure of a plasma equilibrium magnetic field coil according to claim 1, wherein:   The said thick part of the said pressure relaxation board is provided in the center part of the said pressure relaxation board facing the center part between the both said extension parts of the said clamp, The Claim 1 or 2 characterized by the above-mentioned. Support structure for plasma equilibrium magnetic field coil.

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