KR100683165B1 - Poloidal field coil structure of bending type of tangent direction for superconducting tokamak - Google Patents

Abstract

A PF(Poloidal Field) coil structure of a bending type of a tangential direction of a superconducting tokamak is provided to absorb intensity enough to endure an electromagnetic force and contraction transformation by connecting a PF coil fixing unit to a PF coil supporting unit and a base block attached to a PF coil by a moving plate. A PF coil structure of a bending type of tangential direction of a superconducting tokamak includes a PF coil supporting unit(10a), a moving plate(22), and a PF coil fixing unit(10). The PF coil supporting unit(10a) supports a PF coil to a toroidal coil. The moving plate(22) is connected to left/right sides and inner/outer sides of the PF coil supporting unit(10a). The PF coil fixing unit(10) fixes the PF coil and is connected to the moving plate(22). A base block(30) is attached to the toroidal coil. A lower plate is horizontally attached to an upper part of the base block(30). A supporting wall(12a) is attached to inner/outer sides of the lower plate. An upper block(14) is horizontally attached to an upper part of the supporting wall(12a). The fluid plate(22) is connected to inner/outer sides of left/right sides of a lower part of the upper block(12).

Description

Tangential Bending Poroidal Coil Structure of Superconducting Tokamak Device {POLOIDAL FIELD COIL STRUCTURE OF BENDING TYPE OF TANGENT DIRECTION FOR SUPERCONDUCTING TOKAMAK}

1 is a perspective view of a superconducting tokamak device is installed PF coil structure according to the present invention.

Figure 2 is a perspective view of the upper structure of the PF coil structure according to the present invention.

Figure 3 is a perspective view of the substructure of the PF coil structure according to the present invention.

Figure 4 is a front view of the PF coil structure according to the present invention.

Figure 5 is a cross-sectional view of the front middle portion (B-B of Figure 6) of the PF coil structure according to the present invention.

Figure 6 is a cross-sectional view A-A of Figure 5 in accordance with the present invention.

Explanation of symbols on the main parts of the drawings

10. PF Coil Government 11. Lower Block

14. Upper block 16. Stud bolt

17. Cover block 18. Connecting material

10a. PF coil support 11a. Bottom plate

12a. Support wall 13a. Support plate

22. Flow Plate 23. Space

30. Base Block 50. Poordal Coil

60. Toroidal Coil

The present invention relates to a PF (POLOIDAL FIELD) coil structure of a Tokamak device, which is a nuclear fusion experiment apparatus, and more particularly, in the PF coil structure No. 6 of the PF coil structure supporting the donut-type poroid coil, The present invention relates to a PFC coil structure of a superconducting tokamak device for securing stability due to thermal, structural, and electrical deformation.

The Tokamak apparatus, a fusion experiment apparatus, consists of a toroidal coil for confining deuterium in a plasma state to a strong magnetic field, and a poroidal coil for generating plasma and controlling its position and shape. Coil structures for supporting the weight of these large coils and the magnetic force by the strong magnetic field are manufactured according to the characteristics of each coil. Since the assembly error is determined according to the precision of the coil structure, the structure should be manufactured in consideration of the characteristics of the assembly.

Conventional tokamak devices have been difficult to operate for a long time due to Joule heat loss due to high current by using a phase conducting conductor, but recently a design has been made to enable continuous operation using a superconducting conductor having no electrical resistance. Since the phase-conducting tokamak device operates at room temperature, the thermal characteristics of the coil structure were not the main considerations. Also, unlike the superconducting coils, the phase-conducting coils did not significantly reduce the driving ability due to the stress caused by the magnetic force.

FIG. 1 illustrates a tangentially bent type poroid coil structure 100 of a superconducting tokamak device. As described above, the superconducting coil structure of the tokamak device includes a toroidal coil structure 60, which is made of an in-pipe stranded conductor (CICC), a method of enclosing a superconducting wire with a rectangular metal tube, and then connecting the conductor to the winder equipment. It comprises a coil wound in the form of D, 16 such D-shaped coil is made. The supercritical liquid helium is flowed through the in-pipe twisted conductor at a pressure of about 5 atm, and the superconducting wire is cooled to cryogenic temperature to become a superconducting coil. When a 35 kA direct current flows here, the magnetic field strength reaches a maximum of 7.2 T, and the magnetic field traps the plasma in the tokamak. The toroidal coils continuously form a toroidal magnetic field. The central solenoid (CS) coil and the poroid coil produce a plasma by rapidly changing the poroid magnetic field, and control the position and shape of the plasma. The magnet system of the tokamak device is composed of the toroidal coil, the central solenoid coil and the poroid coil. The central solenoid coil and the structure are in the center of the tokamak device, and the three-pair (5, 6, 7 PF coil structures) are vertically symmetrical while the outer coil and the PF coil structure 100 are not shown. The vacuum vessel in which the plasma is confined is configured in the donor form in the inner space of the D-shaped toroidal coil structure.

The superconducting coil of the superconducting tokamak device operates at a cryogenic temperature of about 4.5K and is vulnerable to structural deformation and thermally unstable. Therefore, it is necessary to establish an environment that satisfies the operating conditions in order to improve the stability of the tokamak operation.

To this end, the PF coil structure supports the weight of all the low-temperature structures and toroidal coils, which are superconducting coils, and supports the thermal, structural, and electrical stability to design the structure in consideration of manufacturing characteristics, assembly characteristics, and repair characteristics. Performance is very important.

In other words, the PF coil structure requires support structures of different shapes depending on the coil size, the current applied and the position. Superconducting magnets operating in cryogenic (4.5 K) and high magnetic fields generate heat shrinkage by cooling and electromagnetic force by applying current, which is an important factor in designing support structures. In addition, the PF structure is connected to the foundation block of the TF coil structure, so it is necessary to understand the relative behavior. Electromagnetic forces acting on the PF coil structure are generated in the vertical and radial directions.

In particular, since the vertical force can act as a attraction force and a repulsive force between the coils symmetrical according to the direction of the current, the structure must be flexible in the radial direction, and must be robust in the vertical direction. In addition, the flexible structure must satisfy the buckling conditions caused by the compressive force. Development of a PF coil structure that satisfies these conditions is required.

Therefore, the technical problem to be achieved in the present invention is to secure the thermal, structural and electrical stability of the capacitive coil of the superconducting tokamak device operated at 4.5K to absorb sufficient strength and shrinkage deformation to withstand electromagnetic force, and to manufacture and assemble It is to provide an easy PF coil structure.

In the tangential bend-type poroid coil structure of the superconducting tokamak device of the present invention for solving the above technical problem, in the PF coil structure for supporting the toroidal coil 50, the poroidal PF coil support 10a supporting the coil 50 to the toroidal coil 60; and a flow plate 22 connected to the inside and the outside of the PF coil support 10a; and the captive coil 50 It is characterized in that it comprises a PF coil fixing portion 10 is fixed to and connected to the flow plate (22).

The PF coil support 10a includes: a base block 30 attached to the toroidal coil 60; and a lower plate 11a horizontally attached to an upper portion of the base block 30; and the lower plate 11a. A support wall 12a attached to the outside; and a support plate 13a supporting the attachment portion of the lower portion of the support wall 12a and the lower plate 11a; and horizontally attached to an upper portion of the support wall 12a. It provides a tangential bend-type poroid coil structure of the superconducting tokamak device, characterized in that the flow plate 22 comprises an upper block 14 connected to the inner and outer sides of the lower left and right, respectively.

PF coil fixing part 10, the left and right sides of the PF coil support (10a) and the lower block 11 which is connected to the upper and inner side to the bottom of the flow plate 22; and the same flow plate 22 is connected A tangent of the superconducting tokamak device, comprising one or more stud bolts 16 connected to the lower block 11 on the ship; and a cover block 17 connected to the inside and the outside of the stud bolts 16. Provided is a directional bend type poroid coil structure.

Connection member 18 is provided between the lower block 11 to provide a tangential bending type poroid coil structure of the superconducting tokamak device, characterized in that for connecting the lower block 11 on both sides.

One or more spaces 23 penetrate the inside of the flow plate 22 to provide a tangential bend-type poroid coil structure of the superconducting tokamak device, which is characterized in that it absorbs displacement of the poroid coil 50.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 2 shows a perspective view of the upper structure of the PF coil structure according to the present invention.

As shown in FIG. 2, the PF coil structure is a structure for supporting the toroidal coil 50 to the toroidal coil 60, and is attached to the toroidal coil 60 through the base block 30. The PF coil fixing part 10 is formed on both sides of the PF coil supporting part 10a, and the PF coil supporting part 10a and the PF coil fixing part 10 are connected by the flow plate 22. As the poroid coil 50 shrinks and expands in accordance with changes in temperature and magnetic field, the flow plate 22 flows in the displacement direction of the poroid coil 50.

The PF coil support 10a supports the toroidal coil 60 to the toroidal coil 60. The PF coil support 10a has a lower portion of the base block 30 attached to one side of the toroidal coil 60, and a lower plate 11a is horizontally attached to the upper portion of the base block 30. The support wall 12a is attached to both sides (inside and outside) of the lower plate 11a, and the support plate 13a supports the attachment part of the lower part of the support wall 12a and the lower plate 11a. Here, the inside and the outside direction is defined as the direction toward the center of the tokamak device as the inner side, the direction opposite to the center of the tokamak device as the outside. The upper and lower sides and the left and right directions are directions determined based on the drawings and are relative directions which may be changed in actual application.

The PF coil support 10a is attached to the upper block 14 horizontally on the upper portion of the support wall 12a, and the flow plate 22 to be described later is connected to the inner and outer sides of the lower left and right sides of the upper block 14, respectively. . The upper part of the support wall 12a is connected to the middle portion of the upper block 14, and the flow plate 22 is connected to the inside and outside of the lower left and right sides of the upper block 14 to which the support wall 12a is not connected. .

The upper block 14, the upper part of the support wall 12a and the flow plate 22 are bolted, and the lower part of the support wall 12a and the lower plate 11a are also bolted. 2 shows a state where the bolt is not fastened to the upper block 14 and the support wall 12a.

One end of the flow plate 22 is connected to the inner and outer sides of the lower left and right sides of the upper block 14. The other end of the flow plate 22 is connected to the upper side of one side of the lower block 11 of the PF coil fixing part 10 to be described later. One or more spaces 23 penetrate the inside of the flow plate 22 to absorb displacement of the prisoner coil 50. The displacement of the poroid coil 50 is a relative displacement due to changes in temperature, magnetic field, or the like.

The PF coil fixing part 10 fixes the poroid coil 50 and is connected to the flow plate 22.

The PF coil fixing part 10 is formed on both sides (left and right sides) of the PF coil support part 10a, and the upper inside and outside of the lower block 11 is connected to the lower part of the flow plate 22. One or more stud bolts 16 are connected to the upper portion of the lower block 11, and the fluid plate 22 is fitted on the same line to be connected.

Cover blocks 17 are respectively connected to the inside and the outside of the stud bolts 16. The upper part of the stud bolt 16 is nut. A connection member 18 is installed between the lower blocks 11 to connect the lower blocks 11 on both sides.

Grooves are formed in the upper portion of the lower block 11 and the lower portion of the cover block 17 so as to fit the shape of the poroid coil 50 so that the poroid coil 50 is seated in order to fix the poroid coil 50.

Figure 3 shows a perspective view of the substructure of the PF coil structure according to the present invention. The substructure of the PF coil structure is a structure in which the superstructure of the PF coil structure is symmetrical with respect to the central horizontal plane of the tokamak device. The positions of the lower block 11, the upper block 14 and the cover block 17 are changed.

Figure 4 shows a front state of the PF coil structure according to the present invention.

As shown in FIG. 4, the upper block 14, the support wall 12a, and the upper part of the flow plate 22 are bolted, and the lower part of the support wall 12a and the lower plate 11a are also bolted.

One or more stud bolts 16 are connected to the upper portion of the lower block 11, and the fluid plate 22 is fitted on the same line to be connected. Cover blocks 17 are respectively connected to the tops of the stud bolts 16. The upper part of the stud bolt 16 is finished with a nut.

The connecting member 18 is connected between the lower blocks 11 on both sides to connect the lower blocks 11. The connecting member 18 may be spaced apart from the lower plate 11a so that the lower block 11 is not connected to the lower plate 11a. Therefore, the PF coil support 10a is connected only by the PF coil fixing part 10 and the flow plate 22.

Figure 5 shows a cross-sectional state of the front middle portion (B-B of Figure 6) of the PF coil structure according to the present invention.

As shown in FIG. 5, the foundation block is attached to the upper portion of the toroidal coil 60, and the lower plate 11a is attached to the upper portion of the foundation block. The support wall 12a is bolted to the outside of the lower plate 11a, and the support plate 13a is supported at the lower portion of the support wall 12a so that the lower plate 11a is supported by the support wall 12a. The lower part of the inner support wall 12a is attached to the toroidal coil 60. The upper block 14 is bolted to the upper portion of the inner and outer support walls 12a. Lower block 11 is located on the same line as the connecting member 18, it can be seen that the connecting member 18 is spaced apart from the lower plate (11a) at a predetermined interval.

Figure 6 shows the A-A cross-sectional state of Figure 5 according to the present invention.

As shown in FIG. 6, the PF coil fixing parts 10 are positioned at both sides of the PF coil support part 10a, and the stud bolt 16, the flow plate 22, and the support wall 12a are formed on the same line. . The array of series of stud bolts 16, the flow plate 22 and the support wall 12a is arranged to bend to the curvature of the poroid coil 50.

The design of the PF coil structure is carried out based on the choice of materials, the understanding of the operating loads and the appropriate design criteria. First, in terms of materials, the PF coil structure has excellent strength and toughness even at cryogenic temperatures of 4.5K. Most metallic and nonmetallic materials are brittle at cryogenic temperatures. In this respect, the stainless steel 300 series have excellent low temperature properties and are widely used as low temperature structural materials. Therefore, the main material of the PF structure is preferably SUS 316LN is used to further strengthen the strength and toughness.

Typical load conditions for the magnet structure are the preload of the bolt during assembly, the cooling, the relative strain with the application of TF current, and the electromagnetic force with the application of the current of the PF coil. Table 1 shows the vertical electromagnetic force used in the structural analysis. The PF coil structure of the present invention corresponds to the PF6 coil structure in Table 1.

Vertical force is mainly due to the attraction (+) and repulsive force (-) of the upper and lower coils depending on the direction of the current. For PF5, up to 10.1 MN. In particular, because the PF coil has a large change in current with time, the electromagnetic load can act dynamically and periodically. Therefore, these fatigue loads are considered in the design.

Table 1. Load condition of PF coil for structural analysis

Vertical Magnetic Forces [MN] IM SOF SOB EOB MF PF5 4.84 -0.01 -0.27 -0.43 10.1 / 3.1 PF6 -0.45 1.40 2.17 1.95 3.9 / -3.2 PF7 0.32 0.01 -0.14 0.66 5.8 / -1.4

Note) IM (Initial Magnetization), SOF (Start of Flattop), SOB (Start of Burn), EOB (End of Burn), MF (Maximum Force).

At cryogenic temperatures the material increases in strength while decreasing toughness. In particular, repeated yield after yield strength is one of the cryogenic material properties. Therefore, the structural design standard of the magnet structure was prepared separately based on the ASME code, and the stress tolerance is defined as follows.

* Primary film stress Pm ≤1.0KSm

* Primary membrane stress + bending stress Pm + Pb ≤1.3KSm

* Primary Stress + Secondary Stress Pm + Pb + Q ≤1.5KSm

Where Sm is the design stress at operating temperature and is defined as 2/3 of the yield strength. K is the stress concentration coefficient.

As shown in FIG. 2, the PF coil structure may have a radial flexibility using a thin plate flow plate, and may have a structure capable of withstanding vertical electromagnetic force by using a stud bolt and a support wall. And the connection of the flow plate and the lower block is electron beam welding is used.

Table 2 shows the stress analysis results for the PF coil structure. The maximum stress of the stud bolt is 165 MPa and is generated during assembly at room temperature. The maximum stress during operation is 205 MPa in the lower block and cover block, and most of the stresses are far below the allowable values. On the fatigue side, the stud bolts, the lower block and the cover block show alternating stresses of 100 MPa and 130 MPa or less, respectively, and have sufficient fatigue life.

Table 2. PF Coil Structure Structural Analysis Results

Parts Load Condition Stress Intensity (max.), MPa Allowable Stress, MPa Stud Assembly 165 750 Blocks MRF 205 650 Flex. plate MRF 161 650

Note) Maximum Repulsive Force (MRF)

In the present invention, the design criteria, design progress, and structural analysis results of the KSTAR PF coil support structure are presented. The analytical results demonstrate the structural feasibility of the current design, and in particular have sufficient safety margin for fatigue life as well as static strength.

While the invention has been described and illustrated in connection with a preferred embodiment for illustrating the principles of the invention, the invention is not limited to the construction and operation as shown and described. Rather, it will be apparent to those skilled in the art that many changes and modifications to the present invention are possible without departing from the spirit and scope of the appended claims. Accordingly, all such suitable changes and modifications and equivalents should be considered to be within the scope of the present invention.

As described above, the PF coil structure of the present invention connects the PF coil fixing part with the basic block attached to the toroidal coil by a flow plate to the PF coil support part, thereby connecting the poroidal coil which is a high magnetic field generating device operated at cryogenic temperatures. By designing and manufacturing to satisfy the thermal, structural and electrical stability of supporting PF coil structure, it absorbs sufficient strength and shrinkage deformation to withstand electromagnetic force, and secures the performance and stable operation characteristics of superconducting fusion test apparatus. Can be provided.

Claims (8)

In the PF coil structure that supports the toroidal coil 50 to the toroidal coil 60, A PF coil support part 10a for supporting the toroidal coil 50 to the toroidal coil 60; A flow plate 22 connected to the inside and the outside of the left and right sides of the PF coil support 10a; And The tangential bending type poroid coil structure of the superconducting tokamak device, characterized in that it comprises a PF coil fixing portion (10) fixed to the captive coil 50 and connected to the flow plate (22). The method according to claim 1, The PF coil support 10a, A basic block 30 attached to the toroidal coil 60; A lower plate (11a) attached horizontally to the upper portion of the base block (30); A support wall 12a attached to the inside and the outside of the lower plate 11a; And Tangential bending of the superconducting tokamak device, characterized in that it is attached to the upper portion of the support wall (12a) horizontally, and the fluid plate 22 is connected to the inner and outer sides of the lower left and right, respectively. Type poroid coil structure. The method according to claim 2, A support plate (13a) is formed on the attachment portion of the lower portion of the support wall (12a) and the lower plate (11a) to support the attachment portion tangential bending type poroid coil structure of the superconducting tokamak device. The method according to claim 2, The base block is attached to both lower sides of the lower plate tangentially bend-type poroid coil structure of the superconducting tokamak device, characterized in that to support the lower plate on the top of the toroidal coil in a balanced manner. The method according to claim 1, The PF coil fixing unit 10, A lower block 11 connected to the inner and outer sides of the lower side of the flow plate 22 while being the left and right sides of the PF coil support 10a; One or more stud bolts 16 connected to the lower block 11 on the same line to which the flow plate 22 is connected; And Tangential bending type poroid coil structure of the superconducting tokamak device, characterized in that it comprises a cover block (17) connected to the upper and inner sides of the stud bolts (16). The method according to claim 5, A connecting member 18 is installed between the lower block 11 to connect the lower block 11 on both sides of the tangential bending type poroid coil structure of the superconducting tokamak device. The method according to claim 1, One or more spaced portions 23 penetrate the inside of the flow plate 22 to absorb displacement of the captive coil 50. The method according to claim 1, The arrangement of the PF coil support, the flow plate, and the PF coil fixing part is formed to be bent in accordance with the curvature of the poroid coil to stably support the annular poroid coil. Coil structure.

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