JP2009281684A - Magnetic refrigerating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure high heat exchanging efficiency by improving the durability of magnetic working substances. <P>SOLUTION: The inside of a central duct 7 filled with the magnetic working substances is provided with a partitioning plate 16 composed of a lateral plate 17 for dividing the inside of the central duct 7 into two in the thickness direction, and longitudinal plates 18 orthogonally connected with the lateral plate section 17 and dividing the inside of the central duct 7 into ten in the longitudinal direction, and thus the inside of the central duct 7 is divided into twenty filling chambers 19 in parallel with each other and connecting between end ducts 10, 11. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a magnetic refrigeration apparatus using the magnetocaloric effect of a magnetic working material.

In recent years, a magnetic refrigeration apparatus using a property (magneto-caloric effect) that causes a large temperature change when a magnetic working material is magnetized or demagnetized has been attracting attention in place of a conventional gas refrigeration apparatus using a gas refrigerant such as Freon. ing. As the magnetic field generating means that acts on the magnetic work substance, a superconducting magnet or the like that can generate a high magnetic field is advantageous, but it requires a large amount of power to maintain a superconducting magnet that operates near 4K (−269 ° C.). In a magnetic refrigeration apparatus having a refrigeration capacity of about 1 to 10 kW or less, such as a refrigerator or an air conditioner, a compact form using a permanent magnet that does not require power for generating a magnetic field is desired.
Therefore, the present applicant has proposed a magnetic refrigeration apparatus using a permanent magnet as magnetic field generating means in Patent Document 1.

This consists of a rotor that is rotated by a driving means and has a permanent magnet fixed to the peripheral surface, and the rotor is pivotally supported, and the inner surface is filled with a granular magnetic working material whose temperature changes in accordance with the increase or decrease of the magnetic field. An apparatus main body having a cylindrical stator in which a duct adjacent to the permanent magnet is disposed, and a cooling fluid circulation means for circulating a cooling fluid (water, etc.) in a circulation path formed by connecting the ducts, A heat exchanger that is provided in the circulation path and performs heat exchange between the cooling fluid and the object to be cooled.
In this magnetic refrigeration apparatus, the magnetic working material is magnetized and the temperature rises due to the approach of the permanent magnet accompanying the rotation of the rotor, and the magnetic working material is demagnetized and the temperature falls due to the separation of the permanent magnet. In accordance with this timing, the cooling fluid circulating means circulates the cooling fluid so that it passes between the ducts, so that the temperature on the low-temperature piping connection side of the duct is lowered to a temperature where the refrigerating capacity and the heat load are balanced, The temperature on the pipe connection side is a constant temperature in which the exhaust heat capacity and the refrigeration capacity of the exhaust heat exchanger are balanced.

JP 2008-51409 A

  However, in the duct, the magnetic working material tends to float irregularly due to the flow of the cooling fluid, and the magnetic working material may collide with the inner wall surface of the duct or collide with each other with the magnetic working material, resulting in wear deterioration. is there. Moreover, the flow of the cooling fluid is likely to be non-uniform in a wide duct, resulting in a decrease in heat exchange efficiency.

  Therefore, the present invention provides a magnetic refrigeration apparatus capable of ensuring high heat exchange efficiency by suppressing wear deterioration of a magnetic working substance to improve durability and uniforming a flow of a cooling fluid in a duct. It is aimed at.

In order to achieve the above object, the invention described in claim 1 is characterized in that the filling region of the magnetic working substance in the duct is divided into a plurality of filling chambers parallel to each other by a partition plate.
According to a second aspect of the present invention, in the configuration of the first aspect, in order to further improve the heat exchange efficiency, the partition plate is provided with a communication portion for communicating between adjacent filling chambers. Is.
The invention according to claim 3 is characterized in that, in the configuration of claim 1 or 2, the partition plate is formed of the same material as the magnetic working substance in order to achieve further improvement in heat exchange efficiency. .

According to the first aspect of the present invention, the wear deterioration of the magnetic working material is suppressed and the durability is improved, and the flow of the cooling fluid in the duct is made uniform, so that high heat exchange efficiency can be ensured. It leads to improvement of freezing capacity.
According to the second aspect of the present invention, in addition to the effect of the first aspect, the fluid pressure between the filling chambers is equalized by the communicating portion, and the flow is more uniform, and further improvement in heat exchange efficiency is expected. it can.
According to the third aspect of the present invention, in addition to the effect of the first or second aspect, the contact amount between the cooling fluid and the magnetic working substance increases, leading to further improvement in heat exchange efficiency.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an overall view showing an example of a magnetic refrigeration apparatus. In the magnetic refrigeration apparatus 1, an apparatus main body 2 includes a hollow cylindrical stator 3 whose front and rear ends in the axial direction are closed and whose inside is vacuum-tight. The rotor 4 is provided with a pair of permanent magnets 5 and 5 attached radially to an axially symmetric circumferential surface in the stator 3. The front and rear ends of the rotor 4 are rotatably supported by the stator 3 and are controlled to rotate by a servo motor (drive means) (not shown) connected via a speed reducer.

  Further, four ducts 6, 6... Which are twice as many as the permanent magnets 5 are fixed to the inner periphery of the stator 3 at equal intervals in the circumferential direction so as to be close to the outer peripheral surface of the permanent magnet 5. ing. As shown in FIG. 2, the duct 6 has an arc shape along the inner circumference of the stator 3 and a magnetic working material (here, gadolinium (Gd)) 8 having a particle diameter of 0.6 to 1.0 mm. , 8... Are filled with a hollow central duct 7, and are connected to both ends of the central duct 7 by bolts 9, 9. It consists of. At the end of one end duct 10 in the longitudinal direction (the axial direction of the stator 3), there is an inlet 12 for cooling fluid, and at the end of the other end duct 11 opposite to the end duct 10, Cooling fluid outlets 13 are respectively formed.

Further, on the walls adjacent to each other of the central duct 7 and the end ducts 10 and 11, as shown in FIG. 3, three oval through holes 14, 14. Thus, the central duct 7 and the end ducts 10 and 11 are communicated with each other through the opposing through holes 14 and 14. Further, between the walls at the positions of the opposing through holes 14 and 14, metal nets 15, 15... Having a mesh smaller than the diameter of the magnetic working material 8 are sandwiched and fixed so that the magnetic working material from the central duct 7 is sandwiched. 8 outflow is prevented.
On the other hand, inside the central duct 7, a horizontal plate portion 17 that bisects the inside of the central duct 7 in the thickness direction, and is connected to the horizontal plate portion 17 orthogonally, and the central duct 7 is divided into ten in the longitudinal direction. A partition plate 16 comprising vertical plate portions 18, 18... Is provided, and the inside of the central duct 7 is divided into 20 parallel filling chambers 19, 19... Connecting the end ducts 10, 11. It is divided. The magnetic working substance 8 is filled into each filling chamber 19 equally.

  A low-temperature pipe 21 and a high-temperature pipe 22 led out of the stator 3 are connected to each duct 6 of the apparatus main body 2 to form a circulation path for a cooling fluid (water here). Here, between the pair of ducts 6A and 6A in the axially symmetric position (hereinafter, the reference numerals of the constituent parts are denoted by AB when distinguishing the positions), the low temperature pipe 21A and the high temperature pipe 22A are connected to another group. Between the ducts 6B and 6B, a low temperature pipe 21B and a high temperature pipe 22B are connected, respectively. On the other hand, between a pair of adjacent ducts 6 </ b> A and 6 </ b> B, low-temperature pipes 21 </ b> A and 21 </ b> B are connected to each other via a cooler 23 for cooling the object 24 to be cooled. Further, the high-temperature pipes 22A and 22B of the other adjacent ducts 6A and 6B are connected to a circulator 26 and a waste heat exchanger 27, which are cooling fluid circulation means, via a rotary valve 25.

  The rotary valve 25 has the same structure as that disclosed in Patent Document 1 shown in the background art, and is provided with an inflow port 28 communicating with an inflow chamber provided therein and at 90 ° intervals communicating with the inflow chamber 4. Two outflow ports 29, 29, 30, and 30 are formed, and a valve body provided in the inflow chamber is connected to a shaft formed coaxially with the rotor 4 so as to be integrally rotatable. Here, the inflow port 28 is connected to the circulator 26, and the four outflow ports 29, 30 are connected to the high-temperature pipe 22 </ b> B in a set of axially symmetric positions 29, 30. Is connected to the high-temperature pipe 22A and the other outflow port 30 is connected to the exhaust heat exchanger 27. The cooling fluid supplied from the circulator 6 is supplied to the high-temperature pipes 22A and 22B every 90 ° rotation of the valve body. It is made to supply alternately.

The operation of the magnetic refrigeration apparatus 1 configured as described above will be described.
First, when the permanent magnets 5 and 5 are at 0 ° positions (positions shown in FIG. 1), the magnetic working materials 8A and 8A in the ducts 6A and 6A at the 0 ° and 180 ° positions are magnetized to increase the temperature. Rises. On the other hand, the magnetic working materials 8B and 8B in the ducts 6B and 6B at the positions of 90 ° and 270 ° that are 90 ° out of phase with each other are demagnetized and the temperature is lowered.
At this time, as indicated by the solid line arrow, the cooling fluid passes through the rotary valve 25, the circulating pipe 26 → the high temperature pipe 22B of the duct 6B at the 90 ° position → the duct 6B at the relevant position → the low temperature pipe 21B → the duct at the 270 ° position. 6B hot pipe 22B → duct 6B at the position → cold pipe 21B → cooler 23 → cold pipe 21A at the position 6 ° 180 ° → duct 6A at the position 6 → high temperature pipe 22A → cold pipe 6A at the position 0 ° It is made to circulate in order of 21A-> duct 6A of the said position-> high temperature piping 22A-> rotary valve 25-> waste heat exchanger 27-> circulator 26.
Therefore, the cooling fluid cooled by the magnetic working material 8B whose temperature has decreased is cooled by the cooler 23, and then the magnetic working material 8A whose temperature has been increased and the temperature has been increased is cooled to remove the heat exchanger. Returning to 27, the amount of heat for work is released.

Next, when the rotor 4 is rotated 90 ° together with the permanent magnets 5 and 5 (two-dot chain line positions in FIG. 1), the magnetic working substances 8A and 8A in the ducts 6A and 6A at the positions of 0 ° and 180 ° are The magnetic working materials 8B and 8B in the ducts 6B and 6B at the positions of 90 ° and 270 ° are demagnetized to increase the temperature. At this time, the rotary valve 25 is also rotated 90 ° through the shaft, so that the cooling fluid is circulated from the high-temperature pipe 22A of the duct 6A at the 0 ° position as shown by the dotted arrow. Become.
By repeating this rotation, the temperature of each duct 6 on the side of the low-temperature pipe 21 is lowered to a temperature at which the refrigerating capacity and the heat load are balanced. On the other hand, the temperature at the connection side of the high-temperature pipe 22 of each duct 6 becomes a substantially constant temperature due to the balance between the exhaust heat capacity and the refrigeration capacity of the exhaust heat exchanger 27.

When the cooling fluid is circulated, the cooling fluid flowing in each duct 6 is supplied from the inlet 12 to the end duct 10 and then flows into the central duct 7 from each through hole 14. Since it is divided into a plurality of filling chambers 19, the cooling fluid is divided into the respective filling chambers 19, flows in parallel in the central duct 7, flows from the opposite through holes 14 to the end duct 11, and flows out from the outlet 13. Will do. Therefore, the pressure loss in each filling chamber 19 becomes equal, the flow becomes uniform, and the heat exchange efficiency is improved.
Further, since the magnetic working material 8 in each filling chamber 19 is restrained from moving in the narrow filling chamber 19, the magnetic working material 8 collides with the inner wall surface of the central duct 7 or the partition plate 16, or the magnetic working material 8. It becomes difficult to happen that 8 collide with each other.

  FIG. 4 is a graph showing the difference in refrigeration capacity depending on the presence or absence of a partition plate in the magnetic refrigeration apparatus of the above embodiment, where the horizontal axis represents the flow rate (L / min) of the cooling fluid and the vertical axis represents the refrigeration capacity (W). ing. As test conditions, the high temperature end temperature is 24 ° C., the circulation cycle time is 1.8 sec, and the temperature difference between the high temperature end and the low temperature end is 5 ° C. As is clear from this, even when the flow rate is increased from 3 L / min to 5 L / min, the apparatus in which the partition plate is always provided in the duct has a higher refrigeration capacity than the apparatus in which the partition plate is not provided in the duct. I understand that.

  As described above, according to the magnetic refrigeration apparatus 1 of the above-described form, the filling region (central duct 7) of the magnetic working substance 8 in the duct 6 is divided into a plurality of filling chambers 19, 19,. By classifying, the wear deterioration of the magnetic working material 8 is suppressed and the durability is improved, and the flow of the cooling fluid in the duct 6 is made uniform, so that high heat exchange efficiency can be secured, and consequently the refrigeration capacity is improved. It leads to.

In addition, the division form of the filling chamber in the filling region can be appropriately changed by changing the shape of the partition plate. For example, it is possible to change the number of horizontal plate portions and vertical plate portions as well as to change the number of horizontal plate portions and vertical plate portions as shown in FIG.
Further, as shown in the figure, it is also possible to form a plurality of communication holes 31, 31. If such a communication hole 31 is provided, the fluid pressure between the filling chambers 19 becomes equal, the flow is made uniform, and further improvement in heat exchange efficiency can be expected. Of course, in addition to the communication hole, the form of the communication part can be changed as appropriate, such as a slit or a gap formed between the partition plate standing on one inner wall surface of the duct and the other inner wall surface. Is possible. Further, the filling chamber may be partitioned and formed by alternately arranging partition plates between the opposing inner wall surfaces.

And it is also possible to form a partition plate with the same material (gadolinium etc.) as a magnetic working substance. If it does in this way, the contact amount of a cooling fluid and a magnetic working material will increase, and it will lead to the further improvement of heat exchange efficiency.
Moreover, in the said form, although the partition plate is provided in parallel with the flow of the cooling fluid and the filling chamber is formed, for example, the partition plate is arranged in a crossing manner and in a staggered manner to form the filling chamber. Is also possible. In this case, the cooling fluid flows in a meandering manner in the filling region, and the amount of contact between the cooling fluid and the magnetic working substance increases.
In addition, the form of the duct is not limited to the above structure, and it is appropriately designed such as changing the positions of the inlet and outlet, or forming the central duct and end duct integrally and partitioning both ducts with a partition plate. It can be changed.

1 is an overall configuration diagram of a magnetic refrigeration apparatus. It is explanatory drawing of a duct, (A) shows the plane seen from the axial direction of the stator, (B) shows the cross section seen from the axial center side of the stator, respectively. (A) is an AA arrow line view, (B) is a cross-sectional view of a duct. It is a graph which shows the difference in the refrigerating capacity by the presence or absence of a partition plate. It is explanatory drawing which shows the example of a change of a partition plate.

Explanation of symbols

  1 .... Magnetic refrigeration equipment 2 .... Main body 3 .... Stator 4 .... Rotor 5 .... Permanent magnet 6 ... Duct 7 ... Central duct 8 ... Magnetic work substance 10 11 .. End duct, 12 .. Inlet, 13 .. Outlet, 14 .. Through hole, 16 .. Partition plate, 17 .. Horizontal plate part, 18 .. Vertical plate part, 19 .. Filling chamber, 21 .. Low temperature piping, 22. High temperature piping, 23 ... Cooler, 24 ... Cooled body, 31 ... Communication hole.

Claims (3)

A rotor that is rotated by a driving means and has a permanent magnet fixed on a peripheral surface thereof, and the rotor is pivotally supported, and the inner surface side is filled with a granular magnetic working material whose temperature changes in accordance with the increase or decrease of the magnetic field. A device body having a permanent magnet and a cylindrical stator in which a duct adjacent to the permanent magnet is disposed;
A cooling fluid circulation means for circulating a cooling fluid in a circulation path formed by connecting the ducts;
A heat exchanger provided in the circulation path and performing heat exchange between the cooling fluid and an object to be cooled, and a magnetic refrigeration apparatus comprising:
A magnetic refrigeration apparatus characterized in that the magnetic working substance filling region in the duct is divided into a plurality of parallel filling chambers by a partition plate.   The magnetic refrigeration apparatus according to claim 1, wherein the partition plate is provided with a communication portion that communicates between adjacent filling chambers.   The magnetic refrigeration apparatus according to claim 1 or 2, wherein the partition plate is made of the same material as the magnetic working substance.

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