JPH01281372A - Cooling device - Google Patents

Abstract

PURPOSE:To maintain a high efficiency operation constantly, by dividing an electric motor into two parts, adopting superconductive material for a coil of one part of the motor which is cooled by an auxiliary cooling system. CONSTITUTION:At starting-up of a cooling device, No.2 electric terminals 58 and 59 are connected to an alternative current power source which is equal to the resonance frequency of the system to generate cold heat in an expansion space 6 in a main cooling system and in No.2 expansion space 38 in an auxiliary cooling system 40 respectively. During this process, the low temperature part of No.2 cold finger 36 and a linear motor 28 are rapidly cooled because the low temperature part of the auxiliary cooling system is heat-insulated by a vacuum Dewar vessel 31. At this time, when the temperature of a coil 23 composed of superconductive material falls enough below the critical temperature, the coil 23 reaches superconductive state. Then, the power source connected to the terminals 58 and 59 is switched to terminals 26 and 27 to supply electric current to the coil 23. The electric power supplied to the linear motor 28 is effectively consumed for driving a piston 2 with less heat generation on the coil 23.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a gas cooler used for cooling, freezing, refrigeration, air conditioning, etc., such as a Stirling cooler.

[Conventional technology]

FIG. 3 is a cross-sectional west side view showing the general structure of a conventional Stirling cooler disclosed in Japanese Patent Application No. 1982-270998. In the figure, 1 is a cylinder, and a piston 2 reciprocates inside this cylinder 1. Reference numeral 3 denotes a cold finger, which includes a displacer 4 that reciprocates due to pressure fluctuations of the working gas, and whose lower part communicates with the cylinder 1 through a communication pipe 5. Displacer 4
The upper working surface 4h of , delimits the expansion space 6 and together with the compression space 7 constitutes the working space. A heat accumulator 8 provided in the displacer 4 can communicate with the working gas below it via a central hole 9 and with the working gas above it via a central hole 10 and a radial flow duct 11 . This machine is also equipped with a freezer 12 as a heat exchanger for heat exchange between the expanded cold working gas and the object to be cooled. The piston 2 is provided with seals 13, 14 and between the displacer 4 and the cold finger 3 is provided with a seal 15, 16. The screw thread 2 also has a lightweight sleeve 17 on its underside made of a non-magnetic and non-magnetizable material such as hard paper or aluminum. An annular permanent magnet 18 is fixed to the sleeve 17, and an annular gap 1 is formed in the axial direction of the piston 2.
It is designed to be able to move back and forth within 9 degrees. Annular gap 19
Inside, a magnetic field is created in the radial direction by a closed magnetic circuit consisting of an annular permanent magnet IS, a soft iron annular disk 20°, a soft iron cylinder 21 and a soft iron circular disk 22. Furthermore, a conductor consisting of a superconductor is wound around the soft iron cylinder 21 to form a coil 23 which is connected to lead wires 24.25 passing through the wall of the cylinder 1 and these leads 24.25. are connected to electrical terminals 26 and 27, respectively, outside the cylinder 1. Sleeve 17 mentioned above. Annular permanent magnet 18. Annular gap 19. Soft iron annular disc 20. Soft iron cylinder 21. Soft iron circular disc 22
．． The coil 23 and the leads 1i24, 25 collectively constitute a linear motor 28 for driving the piston. The piston 2 and the displacer 4 are reciprocally engaged with the cylinder 1 and the cold finger 3 via the piston elastic member 29 and the displacer elastic member 30, respectively, and the screws I/N 2 and the displacer 4 are in fixed positions when they are stationary. and determines the neutral position during operation. Furthermore, the vacuum dewar 31 is hermetically fastened to the flange 34 with a seal 32 and bolts 33, and the inside of the vacuum dewar 31 is evacuated by a vacuum pump (not shown) to prevent heat from entering the low temperature part from the outside world. It is supposed to be done. 35 is an object to be cooled, and 1l in the cold finger 3
It is in thermal contact with a low temperature section consisting of the fi space 6 and the freezer 12, and is therefore cooled by a cooler. 36 is a second cold finger; it includes a second displacer 37 that reciprocates due to pressure fluctuations of the working gas. Lower working surface 37 of second displacer 37
a is the 211th! The second expansion space 38 bounds an expansion space 38 which, together with the compression space 7 surrounded by the working surface 2BP of the piston 2, the working surface 4a of the displacer 4 and the working surface 37b of the second displacer 37, A main cooling system 39 constituted by a space 6 and a compression space 7 constitutes an operating space for a sub-cooling system 40 . The second displacer 37 has a second heat storage device 41, and this second heat storage device 41 is connected to the compression space 7 through a central hole 42 located in the upper part of the second heat storage device 41.
It also communicates with the second expansion space 38 via a central hole 43 and a second radial flow duct 44 in its lower part. Further, the second displacer 37 is arranged such that the gas flowing from the compression space 7 to the second expansion space 38 is connected to the second heat storage device 41.
A seal 45,46 is provided to force the passage through. Near the exit of the second radial flow channel L-44, there is a second radial flow pipe that serves as a heat exchanger and extracts the cold heat generated in the working space to the outside.
77) - The 47 is provided and the second cold fin is 36
The near motor 28 is arranged adjacent to the sub-cooling system 40 and is configured to be cooled by the cold heat generated in the low-temperature section of the sub-cooling system 40. The second displacer 37 is reciprocatably engaged with the cylinder 1 via a second displacer elastic member 48, and the second displacer 37 is at a fixed position when at rest and at a center when in operation. determining the position. Next, the operation of the conventional Starisig cooler described above will be explained. When an AC power source (not shown) equal to the resonance frequency of the system is connected to the electric terminals 26 and 27, the coil 23
An alternating current flows in the circumferential direction, and the interaction between this alternating current and the radial magnetic field created by the annular permanent magnet 18 causes a periodic Golentz force to act on the coil 23 in the axial direction C.
Ku. As a result, piston 2. A filter assembly consisting of a sleeve 17 and an annular permanent magnet 18 and an elastic member 29 for the piston.
The system becomes resonant and the assembly vibrates axially. The vibration of the piston 2 is caused by the compression space 7.1 between the amount of strain 6
．． Communication pipe 5. Double heating device8. Center hole 9° Center hole 10. Radial flow group I-11, freezer 12, second expansion space 38. 2nd door heat PJ41. Center hole 42. Center hole 43. While periodically bringing about pressure changes in the working gas sealed in the working space consisting of the second radial flow gas 44 and the second freezer 47, the change in the flow rate of the gas passing through the heat storage device 8 also causes the displacer 4 to The change in the flow rate of the gas passing through the second heat storage device 41 causes a periodic axial alternating vibration force to be generated in the second displacer 37. In this way, the displacer 4 including the heat storage device 8 and the second heat storage device 41 are included. The second displacer 37 is the piston 2
The cold finger 3 and the second cold finger 36 reciprocate in the axial direction at the same frequency but with different phases. When the displacer 4 and the second displacer 37 reciprocate while maintaining an appropriate phase relationship with the pressure fluctuation, the working gas sealed in the working space undergoes a thermodynamic cycle known as the "reverse Stirling cycle". In the main cooling system 39, the expansion space 6
In addition, in the sub-cooling system 40, cold heat is generated in the second expansion space 38. Regarding the above-mentioned "reverse Stirling cycle" and its principle of cold generation, see the literature rCryocool, ersJ (G, Walk
er, Plenum Press, New Year
K, 1983, PP 177-123). The principle will be briefly explained below. While the gas in the compression space 7 compressed by the piston 2 flows through the communication pipe 5, the heat of compression is cooled and the gas in the compression space 7 is cooled down through the center hole 9. i
! Flows into Ffi18. In the heat storage "Ii8", the working gas is pre-cooled by the cold energy stored half a cycle before, and the working gas is further passed through the center hole 10, the radial flow groove 11 and the freezer 1.
2 into the expansion space 6. Then, when most of the working gas enters the expansion space 6, expansion begins, and the expansion space 6
Generates cold heat inside. The working gas then returns through the flow path and enters the compression space 7 while releasing cold heat to the heat storage device 8 in the reverse order. At this time, heat is removed from the outside within the freezer 12 to cool the outside. When most of the working gas returns to the compression space 7, compression begins again and the next cycle begins. Through the process described above, the above-mentioned "reverse Stirling cycle" is completed and cold heat is generated. Although the main cooling system 39 has been described above as an example, the sub-cooling system 40 also mainly generates cold heat in the second expansion air R38 and the second freezer 47 by the same effect. On the other hand, when the cooler is operating, Joule heat generation equal to R2 is generated in the coil 23 due to the electric resistance R of the coil 23 and the flowing current . Moreover, since the low temperature part of the sub-cooling system 40 is insulated by the vacuum dewar 31, if the cooler is designed so that the cooling capacity of the sub-cooling system 40 of the cooler is > Joule light heat, then the above equation can be achieved. The low Q 116 of the second cold finger 36 and the linear motor 28 are cooled and their temperature drops by an amount of heat equal to the difference. In this way, when the temperature of the coil 23, which is an element constituting the linear motor 28, is sufficiently lowered by 1 degree to a certain certain temperature, that is, below the critical temperature, the coil 23 made of superconducting material becomes a superconducting layer and generates electricity. The resistance R becomes extremely small. At this time, the electric power input to the linear motor 28 is bis!・It is effectively consumed as the force for driving t2, and the object to be cooled can be cooled extremely efficiently.

[Problems to be Solved by the Invention] Above t: The conventional cooler is configured as described above, but the Joule heat generation of the coil 23 is large in the normal conduction state, and the cooling of the sub-cooling system 40 of the cooler is When the capacity is exceeded, the temperature of the fill 23 does not fall below the critical temperature, which causes a problem that efficient operation cannot be performed. Furthermore, in order to suppress the Joule heat generation of the coil 23, it is necessary to increase the size of the linear motor 28, resulting in a problem that the cooler becomes large. This invention was made to solve the above-mentioned problems, and aims to provide a cooler that can always operate efficiently. [Means for Solving the Problems] A cooler according to the present invention divides an electric motor, which was conventionally one, into two, and uses a coil formed of a superconducting material only in one of the divided electric motors. The configuration is such that only one electric motor is cooled by the sub-cooling system. In other words, in this invention, part or all of the coil is made of superconducting material? S electric motor, a second Ti air motor whose coil is formed of a normal good conductor, a main cooling system that generates cold heat and cools the object to be cooled by the joint operation of these electric motors and the second motor, and the electric motor. The electric motor is provided with a sub-cooling system for cooling the sub-cooling system, and only the electric motor is disposed adjacent to the fuser of the sub-cooling system. Note that the ordinary conductor is a material such as a pot or aluminum.

[For production]

The electric motor can be divided and only one electric motor can be cooled by the sub-cooling system. Therefore, depending on the capacity of the sub-cooling system, the coil formed of the superconducting material of this electric motor can always be cooled to below the critical temperature.

【Example】

FIG. 1 is a cross-sectional side view showing a schematic configuration of a cooling machine that is an embodiment of the present invention. The same or corresponding parts as in FIG. . In this embodiment, as shown in FIG. 1, in addition to the first linear motor 28, the piston 2 is provided with a lightweight second sleeve 49 made of a non-magnetic and non-magnetic material, such as hard paper or aluminum, on its upper side. ing. A second annular permanent magnet 50 is fixed to the second sleeve 49 and is capable of reciprocating within the second annular gap 51 in the axial direction of the piston 2 . Within the second annular gap 51 is a second annular permanent magnet 50° and a second soft iron annular disk 52. A magnetic field is created in the radial direction by a closed magnetic circuit consisting of a second soft iron cylinder 53 and a second soft iron circular disk 54. Further, a second coil 55 is formed on the second soft iron annular disk 52 by a good conductor such as copper or aluminum, and this second coil 55 is connected to a second lead wire 56,57 passing through the wall of the cylinder 1. These second lead wires 56, 57 are connected to second T4 terminals 58, 59, respectively, outside the cylinder 1. The second sleeve 49 mentioned above. Second annular permanent magnet 50, second annular space 11!51. Second soft iron annular disk 52, second
Soft iron cylinder 53. Second soft iron circular disc 54. The second coil 55 and the second lead wires 56 and 57 collectively constitute a second linear motor 60 for driving the piston. Note that a seal 61 is provided between the piston 2 and the wall of the cylinder 1.
is provided to prevent the room temperature gas in the second linear motor 60 from flowing into the low temperature first linear motor 28. Next, the operation of this embodiment will be explained. When the cooler is started, that is, when the temperature of the coil 23 made of superconductor is higher than the critical temperature and is in a normal conduction state, an AC power source (
(not shown), an alternating current flows in the circumferential direction through the second coil 55, and this alternating current and the second hammered permanent magnet 5
A periodic Lorentz force acts on the second coil 55 in the axial direction due to the interaction with the radial magnetic field created by the coil 55. As a result, bisl, n2. Sleeve 17. Annular permanent magnet 18
The system consisting of the assembly consisting of the second sleeve 49 and the second annular permanent magnet 50 and the elastic member 29 for the piston is in a resonant state, and the assembly vibrates in the axial direction. Bis 1-2
The vibration of the compressed space 7. Expansion space6. Communication pipe 5. Heat storage device8. Center hole9. Center hole 10. Radial flow duct 11.
Freezer 12° second expansion space 38. Second heat storage device 41. Center hole 42° Center hole 43. While periodically bringing pressure changes to the working gas sealed in the working space consisting of the second radial distribution duct 44 and the second freezer 47, the heat storage M8
Due to the change in the flow rate of the gas passing through the displacer 4,
Further, the change in the flow rate of the gas passing through the second heat storage device 41 causes a periodic alternating vibration force in the axial direction to be generated in the second displacer 37 . In this way, the displacer 4 including the heat storage device 8 and the second M heat device 41 are included. The second displacer 37 moves the cold finger 3 and the second cold finger 3 at the same frequency as the piston 2 but at a different phase.
6 in the axial direction. When the displacer 4 and the second displacer 37 reciprocate while maintaining an appropriate phase relationship with the pressure fluctuations, the working gas is sealed in the working space and the working gas is filled with the "reverse star" as described in the operation of the conventional example. constitutes “Ring Cycle”,
In the main cooling system 39, cold heat is generated in the expansion chamber [6, and in the sub-cooling system 40, cold heat is generated in the second expansion space 38. In the above process, no current flows through the coil 23, and therefore no Joule heat is generated in the coil 23. In addition, the low temperature part of the sub-cooling system 40 is a vacuum dewar 3.
1, the low-temperature portion of the second cold finger 36 and the linear motor 28 are cooled rapidly and their temperatures drop. In this way, when the temperature of the coil 23, which is an element constituting the linear motor 28, is sufficiently lowered to a certain certain temperature, that is, below a critical temperature, the coil 23 made of a superconducting material enters a superconducting state. At this time, when the power source (not shown) connected to the second electric terminals 58 and 59 is connected to the electric terminals 26 and 27, a current flows through the coil 23 which is in a superconducting state and starts to drive the cooler. The electrical resistance of the coil 23 in the superconducting state is extremely small, so there is little heat generation due to the slanted resistance, and therefore,
The electric power input to the linear motor 28 is effectively consumed as a force for driving the piston 2, and therefore the object to be cooled can be cooled extremely efficiently. Although a magnet type linear motor is shown as an example, a moving coil type linear motor or a rotary motor may also be used.
, the same effect as the above embodiment is achieved. Further, in the above embodiment, the cold finger 3 and the cylinder 1 are mechanically strongly connected to each other in an integrated cooling machine. However, as in another embodiment of the present invention shown in FIG. A separate cooler may be used in which the fingers 3 and the cylinder 1 are separated from each other via a long communication pipe 5, and the same effects as in the above embodiment can be achieved. Furthermore, in the above embodiments, a gas cooler based on the Stirling cycle was used as an example, but other gas coolers such as the Gifford-McMahon (GM) cycle, the Rankine (vapor compression type) cycle, or the Preyton cycle may be used. A cooler based on a gas cycle may also be used, and the same effects as in the above embodiment can be achieved. Furthermore, in the embodiment described above, the linear motor 28 and the second linear motor 60 were operated independently by changing the switch. 28 and the second linear motor 60 at the same time (this may be operated simultaneously, and the same effect as in the embodiment described above is achieved. [Effects of the Invention] As described above, the present invention can operate the electric motor instead of the conventional one. The structure is such that the electric motor is divided into two parts, and only the coil of one electric motor is made of superconducting material, and is cooled by the sub-cooling system, so the capacity of the electric motor of the superconducting material coil is designed according to the capacity of the sub-cooling system. If you do this, you can always cool the main coil to below the critical temperature.In addition, when you start the cooler, only the second electric motor is operated, and after the superconducting material coil of the other electric motor becomes below the critical temperature, the main coil is cooled down to below the critical temperature. In this case, since the coil generates little heat during startup, operation in a superconducting state can be performed quickly.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional side view showing a schematic configuration of a cooler that is an embodiment of the present invention, FIG. 2 is a cross-sectional side view showing a schematic configuration of a cooler that is another embodiment of the present invention, and FIG. 1 is a cross-sectional side view showing a schematic configuration of a conventional Stirling cooler. 1 cylinder, 2...piston, 2a, 4a, 4b, 3
7a, 37b - working surface, 3 cold 7, (nga, 4
Displacer, 5 communication pipe, 6 expansion strain gap, 7 compression space, 8 heat storage device, 9,10°42.43 center hole,
11. Radial distribution duct, 12. Freezer, 13.
14, 15, 16, 32° 45.46 Seal, 17
・Sleeve, 18 Annular permanent magnet, 19... Annular space, 20 Soft iron annular disk, 21 ・Soft iron cylinder, 22
・Soft iron circular disc, 23 ・Coil, 24.25
・Lead wire, 26.27 Ti electric terminal 28 ・Linear motor, 29 Piston Jul! Member, 30 ・Elastic member for displacer, 31 ・Vacuum dewar-133-
Bolt, 34 Flange, 35... Cooled object, 36...
2nd cold finger, 37... 2nd displacer,
38 Second expansion space, 39 Main cooling system, 40 Sub-cooling system, 41 Second heat storage word, 44 Second radial distribution duct, 47 Second freezer, 48 Second displacer elastic member, 49--Second sleeve, 50-Second annular permanent magnet, 51--Second annular gap, 52 Second soft iron annular disk, 53 Second soft iron cylinder, 54 Second soft iron circular disk, 55 Second coil , 56, 57, 2nd lead wire, 58, 59 2nd electrical terminal, 60 2nd linear motor, 6 tosseal. Note that the same reference numerals in the figures indicate the same or equivalent parts. Agent Masuo Oiwa (2 others) Procedural amendment (voluntary)

Claims (1)

[Claims] An electric motor in which part or all of the coil is made of superconducting material, and a second electric motor in which the coil is made of ordinary good conductor.
An electric motor, a main cooling system that generates cold heat and cools an object to be cooled by the joint operation of these electric motors and a second electric motor, and a sub-cooling system that cools the electric motor. A chiller in which only the electric motor is placed adjacent to a freezer in the system.