JP5823904B2 - Rotating permanent magnet magnetic refrigeration system - Google Patents

Description

  The present invention relates to a rotary permanent magnet magnetic refrigeration apparatus based on a magnetocaloric effect.

  The ferromagnetic material generates heat when a magnetic field is applied adiabatically, and absorbs heat when the magnetic field is removed adiabatically. This is called the magnetocaloric effect and is prominent near the phase transition temperature (Curie temperature) between ferromagnetism and paramagnetism. A magnetic refrigeration apparatus is one in which a low temperature part and a high temperature part are generated by combining the magnetocaloric effect of a ferromagnetic material and the reciprocating flow of a heat exchange medium, and other objects can be cooled using the low temperature part. Since the Curie temperature is unique to the ferromagnetic material, it is necessary to select a ferromagnetic material having a Curie temperature in the temperature range where the magnetic refrigeration apparatus is to be used. In addition, the ferromagnetic material used in the magnetic refrigeration apparatus is called a magnetic working substance.

  In order to increase the magnetocaloric effect and increase the capacity of the magnetic refrigeration apparatus, it is preferable to apply a strong magnetic field and remove the magnetic field. In order to simplify the structure of the magnetic refrigeration apparatus, it is preferable to apply and remove a magnetic field by moving a permanent magnet. Therefore, conventionally, a certain kind of Halbach array permanent magnet magnetic circuit is assembled, and a magnetic field is applied and removed by rotating the permanent magnet magnetic circuit (see Patent Documents 1 and 2 below).

  The inventors of the present application have already proposed this type of magnetic refrigeration apparatus (see Patent Document 3 below).

Special table 2007-522657 gazette JP 2008-051412 A JP 2011-226735 A

  A conventional magnetic refrigeration apparatus will be described with reference to the magnetic refrigeration apparatus of Patent Document 3 described above.

  FIG. 7 is an overall schematic diagram of a conventional magnetic refrigeration apparatus, FIG. 8 is a cross-sectional view of a main body portion having a pair of permanent magnet magnetic circuits in the annular Halbach array, and FIG. 9 is a diagram of the permanent magnet magnetic circuit in the annular Halbach array. FIG. 10 is a top view of the permanent magnet magnetic circuit of the annular Halbach array of FIG. 9.

As shown in FIG. 7, a rotor A having a permanent magnet assembly 101 paired with a permanent magnet magnetic circuit in an annular Halbach array rotates around a common rotating shaft 105, and the flow path of the rotary valve 130 is By switching, the heat exchange medium cooled by the ducts 112A to 112D whose temperature has been demagnetized and cooled is cooled by the cooler 123, and then cooled to the ducts 112A to 112D whose temperature has been increased by excitation. Then, the heat returns to the exhaust heat exchanger 132 and releases the heat for work. In FIG. 7 , B is a stator, 121A and B are low-temperature pipes, 122A and B are high-temperature pipes, 124 is an object to be cooled, and 131 is a circulator.

  More specifically, as shown in FIG. 8, the rotor A side of the main body portion having a pair of permanent magnet magnetic circuits in an annular Halbach array of the magnetic refrigeration apparatus is a non-magnetic container for housing each permanent magnet magnetic circuit. 101A ′, 101B ′, a first annular Halbach array permanent magnet magnetic circuit 102 housed in a nonmagnetic container 101A ′, and a first annular Halbach array permanent magnet magnet housed in a nonmagnetic container 101B ′ A permanent magnet assembly 101, which is a pair of a second annular Halbach array permanent magnet magnetic circuit 103 opposed to the circuit 102, a first annular Halbach array permanent magnet magnetic circuit 102 and a second annular Halbach array permanent magnet. The spacer 104 disposed between the magnetic circuit 103 and the first annular Halbach array permanent magnet magnetic circuit 102 and the second annular Halbach arrangement Comprising a common rotary shaft 105 to be fitted and a permanent magnet magnetic circuit 103 and the spacer 104.

  On the other hand, on the stator B side of the main body portion having the pair of permanent magnet magnetic circuits in the annular Halbach array of the magnetic refrigeration apparatus, the first annular Halbach array permanent magnet magnetic circuit 102 and the second annular Halbach array permanent magnet are provided. A duct 112 containing a magnetic working material arranged in a magnetic field space 111 where a very large magnetic field can be generated between the surface facing the magnetic circuit 103, a holder 113 for supporting the duct 112 containing the magnetic working material, this holder 113, a support plate 114 that supports the support column 114, a side plate 115 that supports the support column 114, a bearing 116 that is disposed between the common rotary shaft 105 and the side plate 115, and a bearing retainer 117 that holds the bearing 116.

  As described above, in the permanent magnet magnetic circuit, the permanent magnet is fixed by the non-magnetic material, for example, 3 mm non-magnetic plates 101A and 101B so as not to prevent the permanent magnet from falling off. Adjustment of the magnetic field was difficult, and there was a problem in terms of strengthening the magnetic field in the gap in the magnetic circuit.

  In order to solve these problems, the present invention uses a pair of permanent magnet magnetic circuits of an annular Halbach arrangement fitted to a common rotating shaft, and a portion for fixing the permanent magnet of the pair is made of a magnetic metal body. An object of the present invention is to provide a rotary permanent magnet magnetic refrigeration apparatus that is composed of a cover plate and can reinforce the magnetic field in the vicinity of the magnetic circuit and adjust the magnetic field distribution.

In order to achieve the above object, the present invention provides
[1] An annular Halbach array of permanent magnet magnetic circuits fitted to a common rotating shaft is used, a cover plate is disposed at a portion for fixing the permanent magnet of the pair, and the cover plate is made of a magnetic metal body. The rotating permanent magnet magnetic refrigeration apparatus is characterized in that a tapered surface is formed in the peripheral portion of the lid plate and the tapered surface is pressed by a frame plate .

[ 2] A pair of permanent magnet magnetic circuits in an annular Halbach arrangement fitted to a common rotating shaft is used, and a cover plate is arranged at a portion where the permanent magnets of the pair are fixed, and the cover plate is made of a magnetic metal body. The rotary permanent magnet magnetic refrigeration apparatus is characterized in that a step portion is formed in the peripheral portion of the lid plate and the step portion is pressed by a frame plate .
[ 3] The rotary permanent magnet magnetic refrigeration apparatus according to [1] or [2] , wherein the lid plate is made of an iron plate .

  According to the present invention, a conventional pair of permanent magnet magnetic circuits in an annular Halbach arrangement fitted to a common rotating shaft is used, and a lid is used instead of a non-magnetic plate at a portion for fixing the pair of permanent magnets. A plate is arranged, and the lid plate is made of a magnetic metal body, so that the magnetic field near the magnetic circuit can be strengthened and the magnetic field distribution can be adjusted.

It is a cross-sectional schematic diagram of the fixing part of the permanent magnet of the permanent magnet magnetic circuit of the annular | circular shaped Halbach arrangement | sequence fitted to the common rotating shaft which shows 1st Example of this invention. It is a top schematic diagram of the permanent magnet assembly of the permanent magnet magnetic circuit of the annular | circular shaped Halbach arrangement | sequence fitted to the common rotating shaft which shows 1st Example of this invention. It is a cross-sectional schematic diagram of the fixing part of the permanent magnet of the permanent magnet magnetic circuit of the annular | circular shaped Halbach arrangement | sequence fitted to the common rotating shaft which shows 2nd Example of this invention. It is a top schematic diagram of the permanent magnet assembly of the permanent magnet magnetic circuit of the annular | circular shaped Halbach arrangement | sequence fitted to the common rotating shaft which shows 2nd Example of this invention. It is a figure which shows the magnetic field analysis result of the magnetic circuit of a prior art example. It is a figure which shows the magnetic field analysis result of the magnetic circuit of this invention. It is a whole schematic diagram of the conventional magnetic refrigeration apparatus. It is sectional drawing of the main-body part which has a pair of the permanent magnet magnetic circuit of the annular | circular Halbach arrangement | sequence of the conventional magnetic refrigeration apparatus. It is a schematic diagram which shows the pair of the permanent magnet magnetic circuit of the annular | circular Halbach arrangement | sequence of the conventional magnetic refrigeration apparatus. FIG. 10 is a top view of the permanent magnet magnetic circuit of the annular Halbach array of FIG. 9.

The rotary permanent magnet magnetic refrigeration apparatus of the present invention uses a pair of permanent magnet magnetic circuits in an annular Halbach arrangement fitted to a common rotating shaft, and arranges a lid plate at a portion where the permanent magnet of this pair is fixed, In this rotary permanent magnet magnetic refrigeration apparatus, the lid plate is made of a magnetic metal body, and a tapered surface is formed around the lid plate, and the tapered surface is pressed by a frame plate .

  Hereinafter, embodiments of the present invention will be described in detail.

  FIG. 1 is a schematic cross-sectional view of a fixed part of a permanent magnet of an annular Halbach array permanent magnet magnetic circuit fitted to a common rotating shaft according to a first embodiment of the present invention, and FIG. 2 is fitted to the common rotating shaft. It is the upper surface schematic diagram of the permanent magnet assembly of the permanent magnet magnetic circuit of the made annular | circular shaped Halbach array.

In these drawings, 1 is a permanent magnet assembly, 2 is a permanent magnet (for example, NdFeB) constituting the permanent magnet assembly 1, and 3 is a frame for housing the permanent magnet 2 [ for example, a non-magnetic body or a metal body (SUS). and aluminum)], 4 of the pressing frame plate [thickness 3mm tapered 4A is formed to suppress the pop-out of the permanent magnet 2, for example, non-magnetic or metal body (SUS or aluminum)], 5 jumped out of the permanent magnet 2 A cover plate (magnetic metal plate having a thickness of 2.8 mm: for example, an iron plate) formed with a taper 5A, 6 is a screw for fixing the press frame plate 4 to the frame body 3 in order to fix the cover plate 5 It is a member.

  FIG. 3 is a schematic cross-sectional view of a fixed portion of a permanent magnet of an annular Halbach array permanent magnet magnetic circuit fitted to a common rotating shaft according to a second embodiment of the present invention, and FIG. 4 is fitted to the common rotating shaft. It is the upper surface schematic diagram of the permanent magnet assembly of the permanent magnet magnetic circuit of the made annular | circular shaped Halbach array.

In these drawings, 11 is a permanent magnet assembly, 12 is a permanent magnet (for example, NdFeB) constituting the permanent magnet assembly 11, and 13 is a frame for housing the permanent magnet 12 [ for example, a non-magnetic body or a metal body (SUS). And aluminum)], 14 is a pressing frame plate (a 3 mm thick frame plate: for example, a non-magnetic material or a metal body (SUS or aluminum)), and 15 is a permanent magnet. 12 is a lid plate (magnetic metal plate: iron plate) having a stepped portion 15 </ b> A that holds the projection 15, and 16 holds the press frame plate 14 to the frame body 13 in order to fix the lid plate 15. It is the screw member for.

  According to the present invention, as described above, replacement of the cover plate of the permanent magnet constituting the permanent magnet assembly with iron was performed. Therefore, the conventional example (gap length 22 mm) and the invention in which a 3 mm thick, for example, iron lid plate is arranged immediately before the permanent magnet (gap length 16 mm = 22 mm between permanent magnets—iron plate thickness 3 mm × 2) The spatial distribution of the magnetic field was calculated. In calculation, the thickness of the iron plate was set to 2.8 mm, and the gap between the iron plate and the permanent magnet was secured to 0.2 mm. The type of iron was SS400. These values are obtained when the permanent magnet is N40SH. When the permanent magnet is changed to N48M, the magnetic field must be 1.1 times and the force 1.2 times.

  FIG. 5 is a diagram showing a magnetic field analysis result of a conventional magnetic circuit, and FIG. 6 is a diagram showing a magnetic field analysis result of the magnetic circuit of the present invention.

(1) As a result of calculation of the magnetic circuit (elf), the maximum magnetic field at the center of the gap in the conventional example (gap length = 22 mm) is 9810 G, and the maximum magnetic field at the center of the gap in the present invention (gap length = 16 mm). Was 9040G. Thus, it was found that the present invention is smaller than the conventional example with respect to the maximum magnetic field at the center of the gap. However, compared with the conventional example, the present invention is a trapezoid in which the spatial distribution of the magnetic field is less uneven, and smooth excitation and demagnetization can be realized by rotation. Further, the magnetic field becomes wider fan-shaped central parts component A in a view corresponding to the region of more than 0.8T as shown in FIG. 6, it has a cleaner fan-shape. In the present invention, the gap length of 16 mm is 22 mm between the magnets and the thickness of the cover plate is 3 mm × 2. Moreover, these are values when the permanent magnet is N40SH, and when it is changed to N48M, it becomes 1.1 times.

  (2) As for the force acting on the magnetic circuit, it can be seen that the present invention is larger than the conventional example. That is, in the case of the conventional example, the force acting on the magnetic circuit is 272 kgf, whereas in the case of the present invention, it is 295 kgf. However, in the case of the present invention, the force acting on the magnetic circuit was calculated from magnet 451 kgf-iron cover plate 156 kgf. Moreover, these are values when the permanent magnet is N40SH, and when it is changed to N48M, it becomes 1.2 times.

  (3) It was found that the present invention is larger than the conventional example with respect to the leakage magnetic field at the rear 25 mm and the side 75 mm of the magnet. That is, in the case of the conventional example, the rear maximum magnetic field is 1570 G and the lateral maximum magnetic field is 70 G, whereas in the present invention, the rear maximum magnetic field is 1620 G and the lateral maximum magnetic field is 80 G. Note that these are values when the permanent magnet is N40SH, and when it is changed to N48M, it becomes 1.1 times.

  (4) In addition, it was found that the present invention is smaller than the conventional example with respect to the Z direction maximum magnetic attraction stress of the Gd duct inserted in the center of the gap. Further, as described above, the present invention is a trapezoid with less stress unevenness than the conventional example, and the stress fluctuation due to rotation is suppressed. That is, in the case of the conventional example, the maximum magnetic attraction stress in the Z direction is 446 kPa, whereas in the case of the present invention, it is 380 kPa. Note that these are values when the permanent magnet is N40SH, and when it is changed to N48M, it becomes 1.2 times.

  Thus, as compared with the conventional example, the rotary permanent magnet magnetic refrigeration apparatus of the present invention can reinforce the magnetic field near the magnetic circuit and adjust the magnetic field distribution.

  In addition, this invention is not limited to the said Example, Based on the meaning of this invention, a various deformation | transformation is possible and these are not excluded from the scope of the present invention.

  The rotating permanent magnet magnetic refrigeration apparatus of the present invention can be used as a rotating permanent magnet magnetic refrigeration apparatus that can reinforce the magnetic field in the vicinity of the magnetic circuit and adjust the magnetic field distribution.

DESCRIPTION OF SYMBOLS 1,11 Permanent magnet assembly 2,12 Permanent magnet 3,13 Frame body which accommodates permanent magnet 4,14 Holding frame board 4A , 5A taper 5,15 Cover plate 6,16 Screw member 14A , 15A step part

Claims (3)

With pairs of permanent magnets the magnetic circuit of the common rotary shaft mated annular Halbach array, a cover plate is arranged in a portion to fix the permanent magnets of the pair, rotary constituting the lid plate of a magnetic metal material A rotary permanent magnet magnetic refrigeration apparatus , wherein a taper surface is formed in a peripheral portion of the lid plate, and the taper surface is pressed by a frame plate . A rotary type in which a pair of permanent magnet magnetic circuits in an annular Halbach arrangement fitted to a common rotating shaft is used, a cover plate is disposed at a portion where the pair of permanent magnets is fixed, and the cover plate is made of a magnetic metal body. A rotary permanent magnet magnetic refrigeration apparatus comprising a stepped portion formed in a peripheral portion of the lid plate and configured to hold the stepped portion with a frame plate . 3. The rotary permanent magnet magnetic refrigeration apparatus according to claim 1, wherein the cover plate is made of an iron plate .