JP5312844B2 - Magnetic refrigeration equipment - Google Patents

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 (magnetocaloric 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 working 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 that balances the exhaust heat capacity and the refrigeration capacity of the exhaust heat exchanger.

JP 2008-51409 A

As magnetic working substances, gadolinium-based materials, lanthanum-iron-silicon compounds, etc. are known, and among these, several types of magnetic working substances with different characteristics are filled in each duct and used in combination. A large temperature difference can be obtained.
However, since the flow rate of the cooling fluid that exchanges heat with the magnetic working material in the duct is equal in the circulation path, it is difficult to ensure a large refrigeration capacity with the magnetic working material on the high temperature side. Refrigerating capacity can be improved by filling a larger amount of magnetic working material on the higher temperature side, but a large amount of magnetic working material is required, leading to an increase in the size of the apparatus.

  Therefore, the present invention provides a magnetic refrigeration apparatus capable of obtaining a large refrigeration capacity with a large temperature difference without increasing the amount of magnetic working material in a so-called hybrid type using several kinds of magnetic working materials in combination. It is for the purpose.

In order to achieve the above object, according to the first aspect of the present invention, the magnetic working substance is arranged with its characteristics changed for each duct so that the temperature becomes lower at the downstream side of the circulation path, while each duct in the circulation path is arranged. Each of the bypass pipes is provided with a bypass pipe for bypassing the downstream circulation path, and each of the bypass pipes is provided with a flow rate adjusting means capable of adjusting the flow rate of the bypass pipe. It is.
The invention according to claim 2 is characterized in that, in the configuration of claim 1, in order to appropriately adjust the flow rate in the bypass pipe, the flow rate adjusting means is a flow rate adjusting valve.
According to a third aspect of the present invention, in the configuration of the first aspect , the flow rate adjusting means is a fixed orifice in order to easily adjust the flow rate in the bypass pipe.
According to a fourth aspect of the present invention, in the configuration according to any one of the first to third aspects, the permanent magnet is fixed to the peripheral surface of the rotor that is rotated by the driving means in order to achieve a configuration that leads to further miniaturization. The duct is disposed on the inner surface of a cylindrical stator that pivotally supports the rotor, and the temperature of the magnetic working material is changed by the contact and separation of the permanent magnet accompanying the rotation of the rotor. To do.

According to the first aspect of the present invention, in a so-called hybrid type using a plurality of types of magnetic working materials in combination, a large refrigeration capacity can be obtained with a large temperature difference without increasing the amount of magnetic working materials. . Therefore, a small and high-performance magnetic refrigeration apparatus can be provided.
According to the second aspect of the present invention, in addition to the effect of the first aspect, the flow rate adjustment in the bypass pipe can be appropriately performed by adopting the flow rate adjustment valve.
According to the third aspect of the invention, in addition to the effect of the first aspect, the flow rate in the bypass pipe can be easily adjusted by adopting the fixed orifice.
According to the invention described in claim 4, in addition to the effect of any one of claims 1 to 3, it is possible to achieve further downsizing of the magnetic refrigeration apparatus.

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. Of the ducts 6, 6,..., One set of ducts 6, 6 adjacent in the circumferential direction has granular magnetic working substances 7, 7,..., And the other set of ducts 6, 6 has granular magnetic work. The working substances 8, 8... Are filled respectively. Here, the types of the magnetic working material 7 and the magnetic working material 8 are different, and the temperature change accompanying the increase and decrease of the magnetic field is lower in the magnetic working material 7 than in the magnetic working material 8.

  Furthermore, a low-temperature pipe 9 and a high-temperature pipe 10 led out of the stator 3 are connected to each duct 6 to form a circulation path for cooling fluid (here, water). Here, between the pair of ducts 6A and 6B in the axially symmetric position (hereinafter, when the positions are distinguished, the reference numerals of the constituent parts are given AB...), The low temperature pipe 9B and the high temperature pipe 10A are the other. A high-temperature pipe 10C and a low-temperature pipe 9D are connected between the two ducts 6C and 6D. Further, between a pair of adjacent ducts 6A and 6C, low-temperature pipes 9A and 9C are connected to each other via a cooler 11 for cooling the object to be cooled 12, and the other sets of ducts 6B and 6D are high-temperature pipes. 10B and 10D are connected to the circulator 14 and the exhaust heat exchanger 15 via the rotary valve 13.

  The rotary valve 13 has the same structure as that disclosed in Patent Document 1 shown in the background art, and is provided with an inflow port 16 communicating with an inflow chamber provided therein and at 90 ° intervals communicating with the inflow chamber 4. Two outflow ports 17, 17, 18, 18 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 16 is connected to the circulator 14, and the four outflow ports 17, 18 are connected to the high-temperature pipe 10 </ b> D at one set 17, 17 in the axially symmetrical position, and in the other set, one outflow port 18 Is connected to the high-temperature pipe 10B and the other outflow port 18 is connected to the exhaust heat exchanger 15, and the cooling fluid supplied from the circulator 14 is supplied to the high-temperature pipes 10B and 10D every 90 ° rotation of the valve body. It is made to supply alternately.

  And between 1 set of duct 6B, 6D to which the high temperature piping 10 is connected to the exhaust heat exchanger 15, respectively, between the low temperature piping 9B, 9D, the 1st bypass pipe 19 provided with the flow regulating valve 20 is provided. It is connected. On the other hand, between the other sets of ducts 6A and 6C to which the low temperature pipe 9 is connected to the cooler 11, the second bypass pipe 21 having the flow rate adjusting valve 22 is also connected between the low temperature pipes 9A and 9C. Has been. Therefore, the flow regulating valve 20 of the first bypass pipe 19 can bypass the ducts 6A and 6C and the cooler 11 in the subsequent stage, and can flow a predetermined amount of cooling fluid to the first bypass pipe 19. The flow rate adjusting valve 22 bypasses the cooler 11 in the subsequent stage and allows a predetermined amount of cooling fluid to flow through the second bypass pipe 21.

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 (solid line positions in FIG. 1), the magnetic working materials 7 and 8 in the ducts 6B and 6A at the 0 ° and 180 ° positions are magnetized to increase the temperature. Rises. On the other hand, the magnetic working materials 7 and 8 in the ducts 6C and 6D at the positions of 90 ° and 270 ° that are 90 ° out of phase with each other are demagnetized to lower the temperature.
At this time, as indicated by the solid line arrow, the cooling fluid is passed through the rotary valve 13 circulator 14 → high temperature piping 10D → duct 6D → low temperature piping 9D → high temperature piping 10C → duct 6C → low temperature piping 9C → cooler 11 → It is made to circulate in order of low temperature piping 9A-> duct 6A-> high temperature piping 10A-> low temperature piping 9B-> duct 6B-> high temperature piping 10B-> rotary valve 13-> exhaust heat exchanger 15-> circulation machine 14.
Therefore, the cooling fluid cooled by the magnetic working materials 7C and 8D whose temperature has been lowered cools the cooled object 12 by the cooler 11, and then cools the magnetic working materials 7A and 8B whose temperature has been increased and increased in temperature. Returning to the exhaust heat exchanger 15, the amount of 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 7A and 8B in the ducts 6A and 6B at the positions of 0 ° and 180 ° are The magnetic working materials 7C and 8D of the ducts 6C and 6D at the positions of 90 ° and 270 ° are demagnetized to increase the temperature. At this time, since the valve body of the rotary valve 13 is also rotated by 90 ° via the shaft, the cooling fluid is circulated from the high-temperature pipe 10B of the duct 6B 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 9 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 10 of each duct 6 is substantially constant due to the balance between the exhaust heat capacity and the refrigeration capacity of the exhaust heat exchanger 15.

During the circulation of the cooling fluid, the flow rate adjustment valve 20 of the first bypass pipe 19 and the flow rate adjustment valve 22 of the second bypass pipe 21 are operated to open the high temperature side in both cases of the forward and reverse of the circulation path. The ducts 6B and 6D filled with the magnetic working material 8 are set to have a larger flow rate than the ducts 6A and 6C filled with the magnetic working material 7 on the low temperature side. Then, a large refrigerating capacity is obtained by the ducts 6B and 6D having a large flow rate, and a large temperature difference is obtained by the ducts 6A and 6C having a small flow rate.
FIG. 2 is a graph showing a relationship between the temperature difference ΔT and the refrigerating capacity P in the magnetic working material. For example, the characteristic of the magnetic working material 8 is a dotted line graph a, and the magnetic working material 7 is a one-dot chain line graph b. In this case, a composite characteristic at the solid line portion c is obtained by adjusting the flow rate.

  As described above, according to the magnetic refrigeration apparatus 1 of the above embodiment, the magnetic working substances 7 and 8 are arranged with different characteristics for each duct 6 so as to be lower in temperature toward the downstream side of the circulation path, while in the circulation path. The first and second bypass pipes 19 and 21 for bypassing the downstream circulation path are respectively provided in the pipes on the outlet side of the ducts 6, and the flow rate adjustment capable of adjusting the flow rate of the bypass pipes in the respective bypass pipes In the so-called hybrid type using a plurality of magnetic working materials 7 and 8 in combination, a large temperature can be achieved without increasing the amount of the magnetic working materials 7 and 8 by providing the means (flow control valves 20 and 22). A large refrigerating capacity can be obtained by the difference. Therefore, a small and high-performance magnetic refrigeration apparatus 1 can be provided.

In particular, here, since a flow rate adjusting valve is employed as the flow rate adjusting means, the flow rate in the bypass pipe can be adjusted appropriately.
Further, the permanent magnet 5 is fixed to the peripheral surface of the rotor 4 rotated by the servo motor, and the duct 6 is disposed on the inner surface of the cylindrical stator 3 that pivotally supports the rotor 4. Since the temperature of the magnetic working materials 7 and 8 changes due to the contact and separation of the permanent magnet 5 accompanying the rotation, further miniaturization of the magnetic refrigeration apparatus 1 can be achieved.

In the above embodiment, four ducts are provided, but depending on the number of permanent magnets, there may be more than this, and in this case, each duct is filled with a magnetic working substance having different characteristics, and each duct What is necessary is just to connect a bypass pipe to the exit side. Further, the circulation path is not limited to the above form, and for example, even when a plurality of ducts are connected in parallel and the cooling fluid flows, a bypass pipe may be connected on the outlet side.
Further, the flow rate adjusting means is not limited to the flow rate adjusting valve, and other means such as a fixed orifice can be employed. In particular, if a fixed orifice is used, the flow rate can be easily adjusted. Of course, a combination of these means may be employed.

And in the said form, although it becomes the structure which made the magnetic working material hybrid in the set of apparatus main body provided with the stator and the rotor, as shown in FIG. In between, the ducts having the same phase are connected in series by pipes 23, 23... To form a circulation path that reciprocates with respect to the heat exchanger 24 such as a cooler, and the respective rotors are rotated synchronously. The present invention can be applied to the device 1a. That is, also here, the characteristic of the magnetic working substance is changed for each duct 6 of each apparatus main body 2 and arranged so that the temperature becomes lower toward the downstream side of the circulation path. What is necessary is just to connect the bypass pipe 25 provided with the flow volume adjustment valve 26, respectively. Of course, in this case as well, the form of the circulation path, the position of the bypass pipe, and the like can be changed as appropriate without departing from the spirit of the present invention.

1 is an overall configuration diagram of a magnetic refrigeration apparatus. It is a graph which shows the relationship between a temperature difference and freezing capacity. It is explanatory drawing which shows the example of a change of a magnetic refrigeration apparatus.

Explanation of symbols

  1, 1a ··· Magnetic refrigeration device ··· Device body 3 ·· Stator 4 ·· Rotor 5 · · Permanent magnet 6 · · Duct 7 · 8 · · Magnetic work material · · · Low temperature pipe, 10 .... High temperature pipe, 11 .... Cooler, 12 .... Cooled object, 14 .... Circulator, 15 .... Exhaust heat exchanger, 19 .... First bypass pipe, 20,22,26 ... -Flow control valve, 21 ... Second bypass pipe, 23 ... Piping, 25 ... Bypass pipe.

Claims (4)

A plurality of ducts filled with a magnetic working material whose temperature changes in accordance with the increase or decrease of the magnetic field is connected to a heat exchanger via a pipe to form a cooling fluid circulation path, and the permanent magnet is relative to the duct. A magnetic refrigeration apparatus that cools the cooling fluid by the magnetic working substance and cools the object to be cooled by the heat exchanger by circulating the cooling fluid through the circulation path.
The magnetic working substance is disposed with a different characteristic for each duct so that the temperature is lower at the downstream side of the circulation path, while the downstream pipe is connected to the pipe on the outlet side of each duct. A magnetic refrigeration apparatus comprising a bypass pipe for bypassing a circulation path, and a flow rate adjusting means capable of adjusting a flow rate of the bypass pipe in each bypass pipe.   The magnetic refrigeration apparatus according to claim 1, wherein the flow rate adjusting means is a flow rate adjusting valve. The magnetic refrigeration apparatus according to claim 1, wherein the flow rate adjusting means is a fixed orifice.   The permanent magnet is fixed to a circumferential surface of a rotor that is rotated by driving means, and the duct is disposed on an inner surface of a cylindrical stator that pivotally supports the rotor, and the rotation of the rotor causes the rotor to rotate. The magnetic refrigeration apparatus according to any one of claims 1 to 3, wherein the temperature of the magnetic working material is changed by contact and separation of a permanent magnet.

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