JP2004087706A - Refrigerator cooling superconducting magnet apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To maintain driving of a refrigerator even in a power interruption in a refrigerator cooling superconducting magnet apparatus having the refrigerator for cooling a superconducting coil on the power supplied from a power source. <P>SOLUTION: The refrigerator cooling superconducting magnet apparatus includes the superconducting coil 18 which is energized by the power supplied from the power source 30, and a GM refrigerator 13 for cooling the coil 18 by the power supplied from the power source 30. When the power supply from the power source 30 is stopped, an electric connection of the refrigerator 13 to the power source 30 is disconnected, and a changeover switch 32 for electrically connecting the refrigerator 13 to the coil 18 is provided. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a refrigerator-cooled superconducting magnet device, and more particularly to a refrigerator-cooled superconducting magnet device having a refrigerator that cools a superconducting coil with electric power supplied from a power supply device.
[0002]
[Prior art]
FIG. 1 shows a refrigerator-cooled superconducting magnet device 100 (hereinafter, referred to as a superconducting magnet device) which is an example of the related art. The superconducting magnet device 100 is used, for example, when growing a silicon single crystal by using a magnetic field applying Czochralski method (MCZ method).
[0003]
As shown in FIG. 1, the superconducting magnet device 100 generally includes a vacuum vessel main body 111, a heat shield plate 116, a Gifford McMahon type refrigerator 113 (hereinafter referred to as a GM refrigerator), a superconducting coil 118, and a power supply device for excitation. 131, a changeover switch 132, a refrigerator compressor 141, and the like.
[0004]
The heat shield plate 116 is provided inside the vacuum vessel main body 111, and a GM refrigerator 113 is disposed above the vacuum vessel main body 111. The GM refrigerator 113 is connected to a refrigerator compressor 141 that compresses a refrigerant via refrigerant pipes 142 and 143. The refrigerant (for example, helium gas) compressed to a high pressure by the refrigerator compressor 141 is supplied to the GM refrigerator 113 via the refrigerant pipe 142.
[0005]
This high-pressure refrigerant is expanded in the GM refrigerator 113, whereby the cold storage material provided in the GM refrigerator 113 is cooled. Further, the refrigerant which has been reduced in pressure by the expansion is returned to the refrigerator compressor 141 via the refrigerant pipe 143, and is again increased in pressure. Each of the GM refrigerator 113 and the refrigerator compressor 141 uses a motor as a drive source, and is configured to be driven by electric power supplied from a power supply 130.
[0006]
The GM refrigerator 113 is connected to a cooling stage 115 that is thermally connected to the superconducting coil 118. Therefore, superconducting coil 118 is cooled to below the critical temperature by GM refrigerator 113 via cooling stage 115, whereby superconducting coil 118 realizes a superconducting state.
[0007]
The vacuum vessel main body 111 forms an annular space in the center thereof, and the superconducting coil 118 is disposed so as to surround the annular space. Therefore, when the superconducting coil 118 is excited, a magnetic field is generated in the annular space formed in the vacuum vessel main body 121, and this annular space functions as a room-temperature magnetic field space 123.
[0008]
The superconducting coil 118 is connected to a power supply 130 via a lead 121, a changeover switch 132, and an excitation power supply 131. The lead 121 is configured so that heat outside the vacuum vessel main body 111 is not transmitted to the superconducting coil 118. Further, the excitation power supply device 131 controls the current supplied to the superconducting coil 118 so that the magnetic field generated in the room-temperature magnetic field space 123 has a predetermined strength.
[0009]
The changeover switch 132 is a relay switch for power failure countermeasures. The changeover switch 132 has a resistor 136 disposed between a pair of terminals 133 connected to the power supply 130 via the excitation power supply device 31 and a pair of terminals 134 connected to the superconducting coil 118 via the leads 121. And a pair of terminals 135 provided.
[0010]
FIG. 1 shows a state in which a power failure has not occurred (hereinafter, referred to as a normal state). In this normal state, the terminals 133 and 134 are connected as shown, and the terminal 135 (that is, the resistor 136) is not connected. Therefore, the power supply 130 is connected to the superconducting coil 118 via the excitation power supply device 131 and the changeover switch 132, and the superconducting coil 118 is excited by the current supplied from the power supply 130.
[0011]
On the other hand, in the normal state, the power supply 130 also supplies power to the GM refrigerator 113 and the refrigerator compressor 141. Accordingly, the GM refrigerator 113 expands the refrigerant by the electric power supplied from the power supply 130 to generate cold and cool the cold storage material. In addition, the refrigerator compressor 141 performs a process of increasing the pressure of the refrigerant using electric power supplied from the power supply 130.
[0012]
FIG. 2 shows a state in which the above-described superconducting magnet device 100 has lost power (hereinafter, referred to as a power failure state). When a power failure occurs, the changeover switch 132, which is a relay switch, switches terminals. More specifically, when a power failure occurs, the changeover switch 132 disconnects the terminal 133 and the terminal 134 and connects the terminal 134 to the terminal 135.
[0013]
In a normal state in which power is supplied from the power supply 130 to the superconducting coil 118, the superconducting coil 118 performs a process of forming a magnetic field in the room-temperature strong magnetic field space 123 and storing power. When a power failure occurs, it is necessary to consume the power stored in the superconducting coil 118. Therefore, the changeover switch 132 performs a switching process to connect the superconducting coil 118 and the resistor 136. As a result, the electric power stored in superconducting coil 118 is consumed when resistor 136 generates heat.
[0014]
Assuming that the resistor 136 is not provided, the GM refrigerator 113 and the refrigerator compressor 141 stop due to a power failure, and the temperature of the superconducting coil 118 rises to change from the superconducting state to the normal conducting state. There is a possibility that a large voltage is generated in the coil 118 and the excitation power supply 131 is damaged. However, by providing the resistor 136 as described above, the excitation power supply device 131 can be prevented from being damaged.
[0015]
[Problems to be solved by the invention]
By the way, when an attempt is made to produce a silicon single crystal using the above-mentioned magnetic field applying Czochralski method (MCZ method) using the superconducting magnet device 100, it takes several days to produce one silicon single crystal ingot. It takes time. In addition, a silicon single crystal is a substrate on which a semiconductor element is manufactured, and therefore, it is required to manufacture an ingot having a certain quality.
[0016]
However, if a power failure occurs during the production of a silicon single crystal and the application of a magnetic field by the superconducting magnet device 100 stops, a region where no magnetic field is applied occurs in the silicon single crystal, and a uniform silicon single crystal Cannot be manufactured.
[0017]
On the other hand, the time of the power failure occurring is about 2 to 3 minutes on average, but if the temperature of the superconducting coil 118 rises within this time and becomes the normal conduction state, it is returned to the superconducting state. It takes several hours to one day to cool down, resulting in a time loss.
[0018]
The present invention has been made in view of the above problems, and a refrigerator-cooled superconducting magnet device that suppresses the occurrence of a quench in a power failure state by enabling the refrigerator to be driven even in a power failure state. The purpose is to provide.
[0019]
[Means for Solving the Problems]
In order to solve the above problems, the present invention is characterized by taking the following means.
[0020]
The invention according to claim 1 is
A superconducting coil that is excited by electric power supplied from a power supply,
And a refrigerator that cools the superconducting coil with electric power supplied from the power supply.
When the power supply from the power supply is stopped, an electrical connection between the refrigerator and the power supply is cut off, and switching means for electrically connecting the refrigerator and the superconducting coil is provided. Is what you do.
[0021]
The invention according to claim 2 is
The refrigerator-cooled superconducting magnet device according to claim 1,
The switching means includes:
A first connection state in which the refrigerator and the power supply are electrically connected depending on whether power is supplied from the power supply, and a second connection state in which the superconducting coil and the refrigerator are electrically connected. It is a relay switch for automatically switching a connection state.
[0022]
The invention according to claim 3 is:
The refrigerator-cooled superconducting magnet device according to claim 1 or 2,
The superconducting coil is characterized in that a magnetic field is applied to a molten crucible of molten polycrystalline silicon during a manufacturing process of a silicon single crystal by a magnetic field applying Czochralski method.
[0023]
The invention according to claim 4 is
A superconducting coil that is excited by electric power supplied from a power supply,
And a refrigerator that cools the superconducting coil with electric power supplied from the power supply.
A power storage flywheel for storing power supplied from the power source,
When the power supply from the power supply is stopped, disconnection of the electrical connection between the refrigerator and the power supply is provided, and switching means for electrically connecting the refrigerator and the power storage flywheel are provided. It is characterized by the following.
[0024]
The invention according to claim 5 is
The refrigerator-cooled superconducting magnet device according to claim 4,
The switching means includes:
A first connection state in which the refrigerator and the power supply are electrically connected, and the refrigerator and the power storage flywheel are electrically connected depending on whether power is supplied from the power supply. It is a relay switch for automatically switching the second connection state.
[0025]
The invention according to claim 6 is:
The refrigerator-cooled superconducting magnet device according to claim 4 or 5,
The superconducting coil is characterized in that a magnetic field is applied to a molten crucible of molten polycrystalline silicon during a manufacturing process of a silicon single crystal by a magnetic field applying Czochralski method.
[0026]
Each of the above-described inventions operates as follows.
[0027]
According to the first aspect of the present invention, when the power supply is interrupted, the switching unit disconnects the electric connection between the refrigerator and the power supply, and the refrigerator and the superconducting coil are electrically connected. The superconducting coil has a characteristic of storing electric power (SMES: Superconducting Magnetic Energy Storage) during normal operation of the refrigerator-cooled superconducting magnet device (meaning that no power failure occurs).
[0028]
For this reason, even if the power supply fails, the superconducting coil storing the power by the SMES serves as the power supply to supply the refrigerator with the power. Therefore, even after a power failure, the superconducting coil can be cooled to maintain the superconducting state, and the magnetic force generated by the superconducting coil can be prevented from fluctuating.
[0029]
According to the second or fifth aspect of the present invention, as the switching means for switching between the first connection state and the second connection state, a relay switch that automatically switches according to whether power is supplied from a power supply is used. Accordingly, the switching process can be performed without providing a detection unit for detecting the stop of the power from the power supply, and the configuration of the switching unit can be simplified. ,
According to the third or sixth aspect of the present invention, the refrigerator maintains the drive regardless of the presence or absence of a power failure, and thus the cooling of the superconducting coil is maintained. Can be kept constant, so that a high-quality silicon single crystal can be manufactured even if a power failure occurs.
[0030]
According to the fourth aspect of the present invention, since the power storage flywheel for storing the power supplied from the power supply is provided, the power storage flywheel is used during the normal operation (meaning no power failure). Flywheels store power.
[0031]
On the other hand, when the power supply fails, the switching unit disconnects the electrical connection between the refrigerator and the power supply, and the refrigerator and the power storage flywheel are electrically connected. The stored power storage flywheel serves as a power source to supply power to the refrigerator. Therefore, even after a power failure, the superconducting coil can be cooled to maintain the superconducting state, and the magnetic force generated by the superconducting coil can be prevented from fluctuating.
[0032]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
[0033]
3 and 4 show a refrigerator-cooled superconducting magnet device 10A (hereinafter, referred to as a superconducting magnet device) according to a first embodiment of the present invention. FIG. 3 shows the superconducting magnet device 10A in a normal state (a state without a power failure), and FIG. 4 shows the superconducting magnet device 10A in a power failure state. The superconducting magnet device 10A is used, for example, when growing a silicon single crystal by using a magnetic field applying Czochralski method (MCZ method).
[0034]
The superconducting magnet device 10A generally includes a vacuum vessel main body 11, a heat shield plate 16, a Gifford-McMahon type refrigerator 13 (hereinafter, referred to as a GM refrigerator), a superconducting coil 18, an excitation power supply 31, a changeover switch 32, and an inverter 36. , A second changeover switch 37, a refrigerator compressor 41, and the like.
[0035]
The heat shield plate 16 is provided inside the vacuum vessel main body 11, and a GM refrigerator 13 is disposed above the vacuum vessel main body 111. The GM refrigerator 13 is connected via refrigerant pipes 42 and 43 to a refrigerator compressor 41 that compresses the refrigerant. The refrigerant (for example, helium gas) compressed to a high pressure by the refrigerator compressor 41 is supplied to the GM refrigerator 13 via the refrigerant pipe 42.
[0036]
The high-pressure refrigerant is expanded in the GM refrigerator 13, whereby the cold storage material provided in the GM refrigerator 13 is cooled. Further, the refrigerant which has been reduced in pressure by the expansion is returned to the refrigerator compressor 41 via the refrigerant pipe 43, and is again increased in pressure. Each of the GM refrigerator 13 and the refrigerator compressor 41 uses a motor as a drive source, and is configured to be driven by electric power supplied from a power supply 30.
[0037]
The GM refrigerator 13 has a first-stage cooling cylinder 14A and a second-stage cooling cylinder 14B. The first-stage cooling cylinder 14A is thermally connected to the top plate 16A, and the second-stage cooling cylinder 14B is thermally connected to the cooling stage 15.
[0038]
Therefore, the GM refrigerator 13 cools the heat shield plate 16 to prevent external heat from entering the heat shield plate 16, and the superconducting coil 18 causes the GM refrigerator 13 (2) to pass through the cooling stage 15. It is cooled below the critical temperature by the stage cooling cylinder 14B). Thereby, superconducting coil 18 realizes a superconducting state.
[0039]
The vacuum vessel main body 11 forms an annular space in the center. The superconducting coil 18 is provided so as to surround this annular space. Therefore, when the superconducting coil 18 is excited, a magnetic field is generated in the annular space formed in the vacuum vessel main body 21, and this annular space functions as a room-temperature magnetic field space 23. An apparatus for producing a silicon single crystal by the MCZ method is disposed in the room temperature magnetic field space 23, and produces a silicon single crystal ingot in a magnetic field generated by the superconducting coil 18.
[0040]
The superconducting coil 18 is connected to a power supply 30 via a lead 21, a changeover switch 32, and an excitation power supply device 31. The lead 21 is configured so that heat outside the vacuum vessel main body 11 is not transmitted to the superconducting coil 18. The excitation power supply device 31 controls the current supplied to the superconducting coil 18 so that the magnetic field generated in the room-temperature magnetic field space 23 has a predetermined strength.
[0041]
The changeover switch 32 is a relay switch for power failure countermeasures. The changeover switch 32 is connected to a pair of terminals 33 connected to the power supply 30 via the excitation power supply 31, a pair of terminals 34 connected to the superconducting coil 18 via the leads 21, and to an inverter 36. It has a configuration having a pair of terminals 35.
[0042]
Similarly to the first changeover switch 32, the second changeover switch 37 is also a relay switch for power failure countermeasures, and is connected to a pair of terminals 38 connected to the power supply 30, the GM refrigerator 13 and the refrigerator compressor 41. A pair of terminals 39 and a pair of terminals 40 connected to the inverter 36 are provided. The inverter 36 performs a process of converting the input into DC and AC.
[0043]
FIG. 3 shows a state in which no power failure has occurred (hereinafter, referred to as a normal state). In this normal state, the first change-over switch 32 connects the terminals 33 and 34, and the terminal 35 is open. Therefore, the power supply 30 is connected to the superconducting coil 18 via the excitation power supply device 31 and the changeover switch 32. Thereby, superconducting coil 18 is excited by the current supplied from power supply 30.
[0044]
The second changeover switch 37 connects the terminal 38 to the terminal 39 and the terminal 40 is open. Therefore, the power supply 30 is connected to the GM refrigerator 13 and the refrigerator compressor 41 via the second changeover switch 37. Thereby, the GM refrigerator 13 and the refrigerator compressor 41 are driven by the electric power supplied from the power supply 30, the GM refrigerator 13 expands the refrigerant to generate cold, and cools the regenerator material. The refrigerant is subjected to high pressure. Therefore, superconducting coil 18 is cooled by GM refrigerator 13 and is brought into a superconducting state.
[0045]
FIG. 4 shows the superconducting magnet device 10A in a power outage state (hereinafter, referred to as a power outage state). When a power failure occurs, the first changeover switch 32 and the second changeover switch 37, which are relay switches, switch terminals.
[0046]
Specifically, when a power failure occurs, the first change-over switch 32 disconnects the terminals 33 and 34 and connects the terminals 34 and 35. The second changeover switch 37 disconnects the terminal 38 from the terminal 40 and connects the terminal 40 to the terminal 39.
[0047]
In this embodiment, an electromagnetic relay switch using a coil is used as each of the changeover switches 32 and 37 for performing the above-described terminal changeover process. The electromagnetic relay switch has an excitation coil internally supplied with a current from a power supply 30 and a connection piece that is displaced by the excitation coil and switches connection of each terminal.
[0048]
Now, the first changeover switch 32 will be described as an example. Since the current is normally supplied from the power supply 130, the excitation coil is excited to attract the connection piece by magnetic force. Thereby, the connection piece connects the terminal 33 and the terminal 34. On the other hand, when a power failure occurs, the current supply from the power supply 30 is stopped, so that the excitation coil is demagnetized, whereby the connection piece is displaced and the terminal 34 and the terminal 35 are connected.
[0049]
As described above, in the present embodiment, the relay switch that automatically switches according to the presence or absence of the supply of the current from the power supply 30 is used. Thus, it is possible to perform the switching processing of the terminal terminals 33 to 35 and 38 to 40 described above.
[0050]
When the changeover switches 32 and 37 are switched as described above, the superconducting coil 18 is electrically connected to the GM refrigerator 13 and the refrigerator compressor 41 via the first changeover switch 32, the inverter 36, and the second changeover switch 37. It will be in the state of being connected.
[0051]
In the normal state in which power is supplied from the power supply 30 to the superconducting coil 18 as described above, the superconducting coil 18 performs a process of forming a magnetic field in the room-temperature strong magnetic field space 23 and storing power. That is, since the superconducting coil 18 functions as a superconducting power storage device (SMES), the superconducting coil 18 can be used as a power supply.
[0052]
Therefore, in the present embodiment, the superconducting coil 18 is electrically connected to the GM refrigerator 13 and the refrigerator compressor 41 in the power failure state. As a result, even if the power supply 30 loses power, the superconducting coil 18 storing the electric power serves as a power supply, and power is supplied from the superconducting coil 18 to the GM refrigerator 13 and the refrigerator compressor 41. At this time, since the electric power supplied from the superconducting coil 18 is DC, it is converted into AC by the inverter 36 and then supplied to the GM refrigerator 13 and the refrigerator compressor 41.
[0053]
Accordingly, the GM refrigerator 13 and the refrigerator compressor 41 maintain the drive regardless of the presence or absence of the power outage, so that the cooling of the superconducting coil 18 is maintained and the occurrence of quench is suppressed. For this reason, when the superconducting magnet device 10A is applied to an apparatus for manufacturing a silicon single crystal by the MCZ method, the magnetic force generated by the superconducting coil 18 can be kept constant even if a power failure occurs. Can be manufactured.
[0054]
Next, a second embodiment of the present invention will be described.
FIGS. 5 and 6 show a superconducting magnet device 10B according to a second embodiment of the present invention. In FIGS. 5 and 6, the same components as those shown in FIGS. 3 and 4 used in the description of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
[0055]
In the superconducting magnet device 10A according to the first embodiment described above, the GM refrigerator 13 and the refrigerator compressor 41 use the superconducting coil 18 as a power source in a power outage state by utilizing the function of the superconducting power storage device (SMES) of the superconducting coil 18. To prevent quench from occurring. On the other hand, the present embodiment is characterized in that a power storage flywheel 50 is used instead of the superconducting coil 18. Hereinafter, the superconducting magnet device 10B will be described in detail.
[0056]
This embodiment also has two first changeover switches 52 and 57. Each of the changeover switches 52 and 57 is constituted by an electromagnetic relay switch that automatically performs a switching process according to the presence or absence of a power failure similarly to the changeover switches 32 and 37 of the first embodiment.
[0057]
The first changeover switch 52 includes a resistor 56 connected between a pair of terminals 53 connected to the power supply 30 via the excitation power supply device 31 and a pair of terminals 54 connected to the superconducting coil 18 via the lead 21. And a pair of terminals 55 provided therein. On the other hand, the second changeover switch 57 includes a pair of terminals 58 connected to the power supply 30, a pair of terminals 59 connected to the GM refrigerator 13 and the refrigerator compressor 41, and a power storage fly through the inverter 36. It has a configuration having a pair of terminals 60 connected to the wheel 50.
[0058]
Here, the power storage flywheel 50 is a device that stores electrical energy as mechanical energy utilizing the flywheel effect. The power storage flywheel 50 includes a flywheel that stores energy, a bearing that supports the flywheel, a power generator that performs energy conversion processing between electric energy and mechanical energy, and the like.
[0059]
In a normal state in which no power failure occurs, the power storage flywheel 50 converts the electric force (electric energy) supplied from the power supply 30 into mechanical energy of rotation of the flywheel and stores the mechanical energy. The mechanical energy stored in the flywheel can be converted into electric power (electrical energy) and output through a power generator. Therefore, the GM refrigerator 13 and the refrigerator compressor 41 can be driven using the power storage flywheel 50 as a power supply.
[0060]
FIG. 5 shows the superconducting magnet device 10B in a normal state where no power failure has occurred. In this normal state, the first changeover switch 53 connects the terminal 53 and the terminal 54 and opens the terminal 55. Therefore, the power supply 30 is connected to the superconducting coil 18 via the excitation power supply device 31 and the changeover switch 52. Thereby, superconducting coil 18 is excited by the current supplied from power supply 30.
[0061]
In addition, the second changeover switch 57 connects the terminal 58 and the terminal 59, and the terminal 60 is open. Therefore, the power supply 30 is connected to the GM refrigerator 13 and the refrigerator compressor 41 via the second changeover switch 57.
[0062]
Thereby, the GM refrigerator 13 and the refrigerator compressor 41 are driven by the electric power supplied from the power supply 30, the GM refrigerator 13 expands the refrigerant to generate cold, and cools the regenerator material. The refrigerant is subjected to high pressure. Therefore, superconducting coil 18 is cooled by GM refrigerator 13 and is brought into a superconducting state.
[0063]
FIG. 6 shows the superconducting magnet device 10B in a power outage state in which a power outage has occurred. When a power failure occurs, the first changeover switch 52 and the second changeover switch 57, which are relay switches, switch terminals.
[0064]
Specifically, when a power failure occurs, the first changeover switch 57 disconnects the terminal 53 from the terminal 54 and connects the terminal 54 to the terminal 55. Thus, superconducting coil 18 is connected to resistor 56. As a result, the power stored in the superconducting coil 18 is consumed by the heat generated by the resistor 56, and therefore, it is possible to prevent the excitation power supply device 31 from being damaged during a power failure.
[0065]
On the other hand, the second changeover switch 57 disconnects the terminal 58 and the terminal 60 and connects the terminal 60 to the terminal 59. By making such a connection, the power storage flywheel 50 is electrically connected to the GM refrigerator 13 and the refrigerator compressor 41 instead of the power supply 30.
[0066]
By the way, in the normal state where power is supplied from the power supply 30 to the power storage flywheel 50 as described above, the power storage flywheel 50 converts electric energy into mechanical energy, Is stored. That is, the power storage flywheel 50 can be used as a power supply.
[0067]
Therefore, in the present embodiment, the power storage flywheel 50 is electrically connected to the GM refrigerator 13 and the refrigerator compressor 41 in the power failure state. As a result, even if the power supply 30 loses power, the power storage flywheel 50 that stores energy serves as a power supply, and power is supplied from the power storage flywheel 50 to the GM refrigerator 13 and the refrigerator compressor 41. At this time, since the power supplied from the power storage flywheel 50 is DC, the power is converted to AC by the inverter 36 and then supplied to the GM refrigerator 13 and the refrigerator compressor 41.
[0068]
Therefore, also in the superconducting magnet device 10B according to the present embodiment, the GM refrigerator 13 and the refrigerator compressor 41 maintain the drive regardless of the presence or absence of the power failure, so that the cooling of the superconducting coil 18 is maintained and the occurrence of quench is suppressed. . For this reason, when the superconducting magnet device 10B is applied to an apparatus for manufacturing a silicon single crystal by the MCZ method, the magnetic force generated by the superconducting coil 18 can be kept constant even if a power failure occurs. Can be manufactured.
[0069]
【The invention's effect】
As described above, according to the present invention, the following various effects can be realized.
[0070]
According to the first aspect of the present invention, even if the power supply fails, the superconducting coil storing the power serves as a power supply to supply power to the refrigerator. Therefore, even after the power failure, the superconducting coil is cooled by the refrigerator. Thus, the superconducting state can be maintained, so that the magnetic force generated by the superconducting coil can be stabilized.
[0071]
Further, according to the second or fifth aspect of the present invention, the switching process can be performed without providing a detection unit for detecting a power stop from the power supply, so that the configuration of the switching unit can be simplified. ,
According to the third or sixth aspect of the present invention, since the magnetic field applied to the molten polycrystalline silicon melting crucible can be kept constant, a high-quality silicon single crystal can be manufactured even if a power failure occurs. be able to.
[0072]
According to the fourth aspect of the present invention, the power storage flywheel, which stores the power even when the power supply fails, serves as a power supply to supply power to the refrigerator. As a result, the superconducting state can be maintained, thereby preventing the magnetic force generated by the superconducting coil from fluctuating.
[Brief description of the drawings]
FIG. 1 is a diagram showing a state of a conventional superconducting magnet device in a normal state.
FIG. 2 is a diagram showing a state of a conventional superconducting magnet device at the time of a power failure.
FIG. 3 is a diagram showing a normal state of the superconducting magnet device according to the first embodiment of the present invention.
FIG. 4 is a diagram illustrating a state of the superconducting magnet device according to the first embodiment of the present invention at the time of a power failure.
FIG. 5 is a diagram showing a state of a superconducting magnet device according to a second embodiment of the present invention in a normal state.
FIG. 6 is a diagram illustrating a state of a superconducting magnet device according to a second embodiment of the present invention at the time of a power failure.
[Explanation of symbols]
10A, 10B superconducting magnet device
11 Vacuum container body
13 GM refrigerator
15 Cooling stage
16 Heat shield plate
18 Superconducting coil
21 Lead
22 hollow cylinder
23 Room temperature strong magnetic field space
30 power supply
31 Excitation power supply
32 1st changeover switch
36 Inverter
37 Second changeover switch
41 Refrigerator compressor
50 Flywheel for power storage
52 first changeover switch
56 Resistance
57 Second changeover switch

Claims (6)

A superconducting coil that is excited by electric power supplied from a power supply,
And a refrigerator that cools the superconducting coil with electric power supplied from the power supply.
When the power supply from the power supply is stopped, an electrical connection between the refrigerator and the power supply is cut off, and switching means for electrically connecting the refrigerator and the superconducting coil is provided. Chiller cooled superconducting magnet device. The refrigerator-cooled superconducting magnet device according to claim 1,
The switching means includes:
A first connection state in which the refrigerator and the power supply are electrically connected depending on whether power is supplied from the power supply, and a second connection state in which the superconducting coil and the refrigerator are electrically connected. A refrigerator-cooled superconducting magnet device, which is a relay switch that automatically switches a connection state. The refrigerator-cooled superconducting magnet device according to claim 1 or 2,
The refrigerator is characterized in that the superconducting coil is configured to apply a magnetic field to a molten crucible of molten polycrystalline silicon during a manufacturing process of a silicon single crystal by a magnetic field applying Czochralski method. Superconducting magnet device. A superconducting coil that is excited by electric power supplied from a power supply,
And a refrigerator that cools the superconducting coil with electric power supplied from the power supply.
A power storage flywheel for storing power supplied from the power source,
When the power supply from the power supply is stopped, disconnection of the electrical connection between the refrigerator and the power supply is provided, and switching means for electrically connecting the refrigerator and the power storage flywheel are provided. A superconducting magnet device cooled by a refrigerator. The refrigerator-cooled superconducting magnet device according to claim 4,
The switching means includes:
A first connection state in which the refrigerator and the power supply are electrically connected, and the refrigerator and the power storage flywheel are electrically connected depending on whether power is supplied from the power supply. A refrigerator-cooled superconducting magnet device, which is a relay switch that automatically switches a second connection state. The refrigerator-cooled superconducting magnet device according to claim 4 or 5,
The refrigerator is characterized in that the superconducting coil is configured to apply a magnetic field to a molten crucible of molten polycrystalline silicon during a manufacturing process of a silicon single crystal by a magnetic field applying Czochralski method. Superconducting magnet device.

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