U.S. patent application number 11/689100 was filed with the patent office on 2007-10-18 for hybrid magnetic refrigerator.
Invention is credited to Katsumi Hisano, Hideo Iwasaki, Akihiro Kasahara, Tadahiko Kobayashi, Akihiro Koga, Akiko Saito, Takuya Takahashi.
Application Number | 20070240428 11/689100 |
Document ID | / |
Family ID | 38603530 |
Filed Date | 2007-10-18 |
United States Patent
Application |
20070240428 |
Kind Code |
A1 |
Koga; Akihiro ; et
al. |
October 18, 2007 |
HYBRID MAGNETIC REFRIGERATOR
Abstract
A compact and highly efficient hybrid magnetic refrigerator
includes a hybrid refrigerating apparatus wherein an evaporator of
a vapor compression refrigeration cycle and a heat exchanger of a
magnetic refrigeration cycle are thermally connected. The magnetic
refrigeration cycle is provided with a magnetic refrigeration unit
in which a magnetic substance dissipates and absorbs heat according
to the increase and decrease of a magnetic field in order to heat
and cool a refrigerant circulating in its vicinity. The heated
refrigerant is cooled by the evaporator of the vapor compression
refrigeration cycle and the cooled refrigerant is supplied to the
heat exchanger cooling the outside air.
Inventors: |
Koga; Akihiro; (Tokyo,
JP) ; Hisano; Katsumi; (Matsudo-shi, JP) ;
Iwasaki; Hideo; (Kawasaki-shi, JP) ; Kasahara;
Akihiro; (Sambu-gun, JP) ; Saito; Akiko;
(Kawasaki-shi, JP) ; Kobayashi; Tadahiko;
(Yokohama-shi, JP) ; Takahashi; Takuya; (Tokyo,
JP) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND, MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Family ID: |
38603530 |
Appl. No.: |
11/689100 |
Filed: |
March 21, 2007 |
Current U.S.
Class: |
62/3.1 ;
62/335 |
Current CPC
Class: |
Y02B 30/00 20130101;
Y02B 30/66 20130101; F25B 25/00 20130101; F25B 21/00 20130101; F25B
2321/0021 20130101 |
Class at
Publication: |
062/003.1 ;
062/335 |
International
Class: |
F25B 21/00 20060101
F25B021/00; F25B 7/00 20060101 F25B007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 30, 2006 |
JP |
2006-095945 |
Claims
1. A hybrid refrigerating apparatus comprising a vapor compression
refrigeration cycle device in which a first refrigerant is
circulated and a magnetic refrigeration cycle device in which a
second refrigerant is circulated, the vapor compression
refrigeration cycle device comprising: a compressor configured to
compress the first refrigerant; a condenser configured to condense
the first refrigerant supplied from the compressor to dissipate
heat from the first refrigerant; an expansion valve configured to
expand the first refrigerant supplied from the condenser; and an
evaporator configured to evaporate the first refrigerant supplied
from the expansion valve to absorb heat from the second
refrigerant, the first refrigerant being supplied from the
evaporator to the compressor; the magnetic refrigeration cycle
device comprising: a pump configured to circulate the second
refrigerant; a magnetic refrigeration unit including a magnet
device configured to generate a magnetic field, a magnetic
substance configured to dissipate or absorb heat in accordance with
the increase and decrease of the magnetic field applied from the
magnetic device, and a heat exchange structure having an
endothermic part in which the second refrigerant is supplied and
the magnetic substance absorbs heat from the second refrigerant; a
first heat exchanger configured to exchange heat between the first
and second refrigerants, to which the second refrigerant is
supplied, the first heat exchanger being thermally connected to the
evaporator of the vapor compression refrigeration cycle, and the
second refrigerant in the first heat exchanger being cooled by the
evaporator; and a second heat exchanger configured to cool an
atmosphere outside the second heat exchanger, the cooled second
refrigerant being supplied to the second heat exchanger.
2. The hybrid refrigerating apparatus according to claim 1, wherein
the heat exchange structure have an exothermic part in which the
second refrigerant is supplied and the magnetic substance
dissipates heat into the second refrigerant.
3. The hybrid refrigerating apparatus according to claim 1, wherein
the second refrigerant is supplied to the endothermic part after
absorbing heat in the evaporator.
4. The hybrid refrigerating apparatus according to claim 2, wherein
the exothermic part is arranged so as to be close to the first heat
exchanger
5. The hybrid refrigerating apparatus according to claim 4, wherein
the exothermic part is arranged at an upstream side of the second
refrigerant in respect to the first heat exchanger.
6. The hybrid refrigerating apparatus according to claim 2, wherein
an heat insulating unit is provided between the exothermic part and
the endothermic part.
7. The hybrid refrigerating apparatus according to claim 1, wherein
the heat exchange structure includes a first pipe in which the
first refrigerant flows and a second pipe in which the second
refrigerant flows, and the first and second pipes are embedded in
the heat exchange structure to form the evaporator and the first
heat exchanger.
8. The hybrid refrigerating apparatus according to claim 7, wherein
the second pipe is provided with a high-temperature side section in
which the heated second refrigerant flows and a low-temperature
side section in which the cooled second refrigerant flows, the
high-temperature side section and the low-temperature side section
are arranged in parallel, the heat exchange structure includes a
tubular section which is arranged in the heat exchange structure so
as to penetrate the high-temperature side section and the
low-temperature side section of the second pipe for the second
refrigerant to form a third heat exchanger, and the magnetic
substance is arranged inside the tubular section.
9. The hybrid refrigerating apparatus according to claim 1, further
comprising an actuator configured to shift the magnetic
substance.
10. The hybrid refrigerating apparatus according to claim 1,
wherein the compressor includes a piston configured to shift the
magnetic material.
11. A hybrid refrigerating apparatus comprising the vapor
compression refrigeration cycle device in which a first refrigerant
is circulated and a magnetic refrigeration cycle device in which a
second refrigerant is circulated, the vapor compression
refrigeration cycle device comprising: a first channel in which the
first refrigerant is circulated; a compressor, provided in the
first channel, configured to compress a first refrigerant; an
expansion valve, provided in the first channel, configured to
expand the first refrigerant; a condenser configured to dissipate
heat from the first refrigerant, the condenser being provided in
the channel between the compressor and the expansion valve; and an
evaporator configured to absorb heat from outside and transfer heat
to the first refrigerant, the evaporator being provided in the
channel between the expansion valve and the compressor; the
magnetic refrigeration cycle device comprising: a pump configured
to circulate the second refrigerant; a branch unit configured to
divide the second refrigerant supplied from the pump into second
and third refrigerant channels; a merging unit configured to merge
the second and third refrigerant channels and return the second
refrigerant through the second and third refrigerant channels to
the pump; a magnetic refrigeration unit including a heat exchange
structure provided with endothermic and exothermic parts, a magnet
device configured to apply magnetic field to either one of the
endothermic part and the exothermic part, and a magnetic substance,
which is shifted between the endothermic part and the exothermic
part, configured to dissipate or absorb heat in accordance with the
increase and decrease of the magnetic field applied from the
magnetic device, the endothermic part being arranged in the second
refrigerant channel to cool the second refrigerant and the
exothermic part being arranged in the third refrigerant channel to
heat the second refrigerant; a first heat exchanger, configured to
cool the second refrigerant, the first heat exchanger being
provided in the second channel and thermally connected to the
evaporator of the vapor refrigeration cycle, and the heated second
refrigerant being supplied to the first heat exchanger; and a
second heat exchanger configured to cool atmosphere outside the
second heat exchanger, the second heat exchanger being provided in
the first channel and the cooled second refrigerant being supplied
to the second heat exchanger.
12. The hybrid refrigerating apparatus according to claim 11,
wherein the exothermic part is arranged so as to be close to the
first heat exchanger.
13. The hybrid refrigerating apparatus according to claim 11,
wherein the exothermic part is arranged at an upstream side of the
second refrigerant in respect to the first heat exchanger.
14. The hybrid refrigerating apparatus according to claim 11,
wherein a heat insulating unit is provided between the exothermic
part and the endothermic part.
15. The hybrid refrigerating apparatus according to claim 11,
further comprising an actuator configured to shift the magnetic
substance.
16. The hybrid refrigerating apparatus according to claim 11,
wherein the compressor includes a piston configured to shift the
magnetic material.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon and claims the benefit of
priority from prior Japanese Patent Application No. 2006-095945,
filed Mar. 30, 2006, the entire contents of which are incorporated
herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a compact size hybrid
magnetic refrigerator.
[0004] 2. Description of the Related Art
[0005] Conventionally, a vapor compression refrigeration cycle has
been generally utilized for a refrigerating apparatus for domestic,
household and business use (refrigeration ability: around 0.1 to 1
kW). As is well known, this vapor compression refrigeration cycle
is provided with a compressor to compress a refrigerant and an
expansion valve to expand the refrigerant. A condenser to dissipate
heat from the refrigerant and an evaporator to absorb heat in the
refrigerant are arranged in the refrigerant channel between the
compressor and the expansion valve. Accordingly, in this vapor
compression refrigeration cycle, the refrigerant supplied from the
compressor dissipates heat at the condenser. The refrigerant
supplied from the condenser is expanded at the expansion valve and
is supplied to the evaporator where heat is absorbed. The
refrigerant is again supplied to the compressor and is compressed.
The characteristics of this vapor compression refrigeration cycle
are given as a temperature-entropy diagram (T-s diagram) and a
compression-enthalpy diagram (p-h diagram), and a reversible cycle
is explained in both diagrams.
[0006] In addition, for special purposes limited to very low
temperature environments, JP-A 2002-106999 discloses a magnetic
refrigeration cycle utilizing a magnetic substance (so-called
magnetic working material), which has an exothermic and endothermic
effect according to the increase and decrease of a magnetic field.
This magnetic refrigeration cycle is arranged with a
superconducting magnet which applies a magnetic field in the
refrigerant channel path between the heat exchangers, and a
magnetic working material having magneto-caloric effect is taken in
and out in this magnetic field. Accordingly, in this magnetic
refrigeration cycle, by the operation of applying or eliminating a
magnetic field to the magnetic working material, exothermic heat
and endotherm from the magnetic working material are given to the
refrigerant in the refrigerant channel path. The cooled refrigerant
is supplied to a radiator, and the refrigerant given heat is
supplied to an exhaust heat exchanger. The magnetic working
material is not limited to a material that generates heat by the
application of magnetic field and absorbs heat when a magnetic
field is eliminated, but is known as a material that absorbs heat
when a magnetic field is applied and generates heat when a magnetic
field is eliminated.
[0007] In recent years, demands for a refrigerating apparatus which
is able to refrigerate down to a low temperature region (-30
degrees Celsius or lower), such as to preserve freshness of food
products using quick freezing (-30 degrees Celsius or lower), is
increasing for domestic, household and business use. However,
conventionally, in order to realize a low temperature region (-30
degrees Celsius) for a vapor compression refrigeration cycle used
generally in, such as, households, it is required to increase its
compression ratio. By responding to such demand, a lubricant or
coefficient of performance (COP) inside the refrigerating apparatus
may deteriorate. Generally, a multistage compression and single
stage expansion refrigerating cycle is employed as measures to
prevent such occurrence. However, such measures are said to be
unsuitable for domestic and household use due to the complexity of
refrigerating system and the high-cost of such apparatus.
[0008] On the other hand, the magnetic refrigeration cycle requires
an extremely large increase and decrease of the magnetic field in
order to generate a large difference in temperature in a magnetic
refrigeration cycle using a magnetic substance having a known
magneto-caloric effect. Accordingly, quite an ambitious and
sophisticated apparatus likewise a superconducting magnet is
required. In a low magnetic field, which can be realized by a
permanent magnet, a magnetic substance being able to generate a
large temperature difference is already developed, and a magnetic
refrigeration cycle using such magnetic substance has been
disclosed in JP-A 2002-106999 (KOKAI).
BRIEF SUMMARY OF THE INVENTION
[0009] According to an aspect of the present invention, there is
provided a hybrid refrigerating apparatus comprising a vapor
compression refrigeration cycle device in which a first refrigerant
is circulated and a magnetic refrigeration cycle device in which a
second refrigerant is circulated,
[0010] the vapor compression refrigeration cycle device
comprising:
[0011] a compressor configured to compress the first
refrigerant;
[0012] a condenser configured to condense the first refrigerant
supplied from the compressor to dissipate heat from the first
refrigerant;
[0013] an expansion valve configured to expand the first
refrigerant supplied from the condenser; and
[0014] an evaporator configured to evaporate the first refrigerant
supplied from the expansion valve to absorb heat from the second
refrigerant, the first refrigerant being supplied from the
evaporator to the compressor;
[0015] the magnetic refrigeration cycle device comprising:
[0016] a pump configured to circulate the second refrigerant;
[0017] a magnetic refrigeration unit including a magnet device
configured to generate a magnetic field, a magnetic substance
configured to dissipate or absorb heat in accordance with the
increase and decrease of the magnetic field applied from the
magnetic device, and a heat exchange structure having an
endothermic part in which the second refrigerant is supplied and
the magnetic substance absorbs heat from the second
refrigerant;
[0018] a first heat exchanger configured to exchange heat between
the first and second refrigerants, to which the second refrigerant
is supplied, the first heat exchanger being thermally connected to
the evaporator of the vapor compression refrigeration cycle, and
the second refrigerant in the first heat exchanger being cooled by
the evaporator; and
[0019] a second heat exchanger configured to cool an atmosphere
outside the second heat exchanger, the cooled second refrigerant
being supplied to the second heat exchanger.
[0020] Further, according to an aspect of the present invention,
there is provided a hybrid refrigerating apparatus comprising the
vapor compression refrigeration cycle device in which a first
refrigerant is circulated and a magnetic refrigeration cycle device
in which a second refrigerant is circulated,
[0021] the vapor compression refrigeration cycle device
comprising:
[0022] a first channel in which the first refrigerant is
circulated;
[0023] a compressor, provided in the first channel, configured to
compress a first refrigerant;
[0024] an expansion valve, provided in the first channel,
configured to expand the first refrigerant;
[0025] a condenser configured to dissipate heat from the first
refrigerant, the condenser being provided in the channel between
the compressor and the expansion valve; and
[0026] an evaporator configured to absorb heat from outside and
transfer heat to the first refrigerant, the evaporator being
provided in the channel between the expansion valve and the
compressor;
[0027] the magnetic refrigeration cycle device comprising:
[0028] a pump configured to circulate the second refrigerant;
[0029] a branch unit configured to divide the second refrigerant
supplied from the pump into second and third refrigerant
channels;
[0030] a merging unit configured to merge the second and third
refrigerant channels and return the second refrigerant through the
second and third refrigerant channels to the pump;
[0031] a magnetic refrigeration unit including a heat exchange
structure provided with endothermic and exothermic parts, a magnet
device configured to apply magnetic field to either one of the
endothermic part and the exothermic part, and a magnetic substance,
which is shifted between the endothermic part and the exothermic
part, configured to dissipate or absorb heat in accordance with the
increase and decrease of the magnetic field applied from the
magnetic device, the endothermic part being arranged in the second
refrigerant channel to cool the second refrigerant and the
exothermic part being arranged in the third refrigerant channel to
heat the second refrigerant;
[0032] a first heat exchanger, configured to cool the second
refrigerant, the first heat exchanger being provided in the second
channel and thermally connected to the evaporator of the vapor
refrigeration cycle, and the heated second refrigerant being
supplied to the first heat exchanger; and
[0033] a second heat exchanger configured to cool atmosphere
outside the second heat exchanger, the second heat exchanger being
provided in the first channel and the cooled second refrigerant
being supplied to the second heat exchanger.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0034] FIG. 1 is a block diagram schematically showing a hybrid
magnetic refrigerator according to an embodiment of the present
invention.
[0035] FIG. 2 is a perspective view schematically showing a
magnetic refrigeration unit shown in FIG. 1.
[0036] FIG. 3 is a block diagram schematically showing a hybrid
magnetic refrigerator according to another embodiment of the
present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0037] There will be described a hybrid magnetic refrigerator
according to an embodiment of the present invention with reference
to the drawings.
[0038] FIG. 1 schematically shows the hybrid magnetic refrigerator
according to a first embodiment of the present invention. The
hybrid magnetic refrigerator shown in this FIG. 1 comprises a
combination of a vapor compression refrigeration cycle 1 and a
magnetic refrigeration cycle 10. In other words, the hybrid
magnetic refrigerator shown in FIG. 1 is provided with a heat
exchange connection 8, which thermally connects the vapor
compression refrigeration cycle 1 and the magnetic refrigeration
cycle 10. An evaporator 2 in the vapor compression refrigeration
cycle 1 and a high temperature side heat exchanger 11 in the
magnetic refrigeration cycle 10 are thermally attached for heat
exchange at this heat exchange connection 8.
[0039] As shown in FIG. 1, the vapor compression refrigeration
cycle 1 comprises a compressor 3 to compress a refrigerant and an
expansion valve 5 to expand the refrigerant. A condenser 4 and the
evaporator 2 within the heat exchange connection 8 are connected in
the refrigerant channel between the compressor 3 and expansion
valve 5. Accordingly, the refrigerant in the refrigeration cycle 1
is compressed at the compressor 3, and this compressed refrigerant
is supplied to the condenser 4 where the heat from the compressed
refrigerant is diffused. The compressed refrigerant is supplied
from the condenser 4 to the expansion valve 5, where it is expanded
and supplied to the evaporator 2. At the evaporator 2, the expanded
refrigerant absorbs heat from the high temperature side heat
exchanger 11 of the magnetic refrigeration cycle 10, which is
thermally connected to the evaporator 2 of the vapor compression
refrigeration cycle 1, so that the high temperature side heat
exchanger 11 is deprived of heat quantity. Here, the evaporator 2
of the vapor compression refrigeration cycle 1 cools off the heat
exchanger 11 of the magnetic refrigeration cycle 10 at
approximately below 0 degrees Celsius, or preferably, in the range
of 0 to -10 degrees Celsius.
[0040] The magnetic refrigeration cycle 10 is provided with a pump
14 to supply the refrigerant into the heat exchange connection 8.
The refrigerant cooled down at the heat exchange connection 8 is
supplied to a heat exchanger 16 where the refrigerant is heat
exchanged between the external environment in which this heat
exchanger 16 is situated and is circulated so that it is supplied
to the pump 14 again. The heat exchange connection 8 is provided
with the heat exchanger 11 and a magnetic refrigeration unit 12,
which has an exothermic unit 12A and endothermic unit 12B. The heat
exchanger 11 and the exothermic unit 12A of the magnetic
refrigeration unit 12 are arranged at the high temperature side,
and the heat exchanger 16 and the endothermic unit 12B of the
magnetic refrigeration unit 12 are arranged at the low temperature
side of this magnetic refrigeration cycle 10. The magnetic
refrigeration unit 12 is provided with a magnet device 18 to apply
magnetic field to the exothermic unit 12A and is connected to an
external actuator 22 so that a magnetic substance 20 having a
magneto-caloric effect is movable between the exothermic unit 12A
and the endothermic unit 12B. This magnetic substance has a
characteristic (magneto-caloric effect) of dissipating and
absorbing heat depending on the increase and decrease of the
magnetic field. The magnetic substance 20 moving between the
exothermic unit 12A and the endothermic unit 12B is arranged in a
tubular housing as explained later and moves therein in piston
action. In the case where the magnetic substance 20 having a
positive magnetic effect wherein the magnetic substance 20
dissipates heat (heat dissipation) when applied a magnetic field
and absorbs heat (cools down) upon demagnetization is incorporated
in the magnetic refrigeration unit 12, the magnet device 18 is
arranged on the high temperature side of the magnetic refrigeration
cycle 10 as shown in FIG. 1. In the case where the magnetic
substance 20 possesses a negative magnetic effect, the magnet
device 18 is arranged on the low temperature side of the magnetic
refrigeration cycle 10. Here, as for the magnetic substance 20
having a negative magnetic effect, the magnetic substance 20
absorbs heat (cools down) when it is applied a magnetic field and
dissipates heat (heat dissipation) upon demagnetization.
[0041] Meanwhile, in this magnetic refrigeration cycle 10, the
magnetic refrigeration unit 12 is arranged on the high temperature
side and the low temperature side of the magnetic refrigeration
cycle 10, and an insulation structure is provided between the high
temperature side and the low temperature side of the magnetic
refrigeration unit 12 in order to prevent heat transfer between the
two sides.
[0042] In the magnetic refrigeration cycle 10 shown in FIG. 1, the
refrigerant supplied from the pump 3 is cooled down to the
temperature of the evaporator 2 at the heat exchanger 11, which is
thermally connected to the evaporator 2 of the vapor compression
refrigeration cycle 1, and is supplied to the exothermic unit 12A
of the magnetic refrigeration unit 12. At the exothermic unit 12A
of the magnetic refrigeration unit 12, the temperature of the
refrigerant is subject to increase from exothermic heat of the
magnetic substance 20, however, maintains a relatively low
temperature such as around 0 degrees Celsius due to being cooled in
advance by the heat exchanger 11. The refrigerant maintained at a
relatively low temperature is supplied to the endothermic unit 12B
of the magnetic refrigeration unit 12 by the pressure from the pump
14. At this endothermic unit 12B, the magnetic substance 20
deprives the refrigerant of heat, and the refrigerant is further
cooled down to, for example, -20 to -30 degrees Celsius. The
sufficiently cooled refrigerant is supplied to the heat exchanger
16 on the low temperature side of the magnetic refrigeration cycle
10 and is returned again to the pump 14 via this heat exchanger 16.
At the heat exchanger 16 on the low temperature side of the
magnetic refrigeration cycle 10, its external environment is cooled
by the supplied refrigerant.
[0043] The cooling temperature difference at each of the vapor
compression refrigeration cycle 1 and the magnetic refrigeration
cycle 10 shown in FIG. 1 is within the range of approximately 20 to
30 degrees Celsius, or, preferably, greater or equal to 30 degrees
Celsius. Accordingly, if it can be cooled down to approximately 0
degrees Celsius at the vapor compression refrigeration cycle 1, the
heat exchanger 16 of the magnetic refrigeration cycle 10 will be
able to refrigerate its environmental temperature down to -30
degrees Celsius or lower.
[0044] FIG. 2 shows an example of the structure of the magnetic
refrigeration unit 12 shown in FIG. 1. As shown in FIG. 1, at the
connection 8, the pipe 42 where the evaporated cooling refrigerant
is circulated intersects with the pipe 44 where the magnetic
cooling refrigerant is circulated, thereby thermally connecting the
evaporator 2 of the vapor compression refrigeration cycle 1 and the
heat exchanger 11 on the high temperature side of the magnetic
refrigeration cycle 10. In other words, the pipes 42 and 44 are
arranged in embedded structure at the connection 8. The pipe 44 for
magnetic cooling refrigerant is horseshoe-shaped. One side of this
horseshoe-shaped pipe 44 for magnetic cooling refrigerant
corresponds to a high temperature side pipe 44A of the magnetic
refrigeration cycle 10 and the other side corresponds to a low
temperature side pipe 44B of the magnetic refrigeration cycle 10. A
tubular section 48 which slidably receives the magnetic substance
20 are so extended as to penetrate through the high temperature
side pipe 44A and the low temperature side pipe 44B, thereby
forming an embedded structure between the pipes 44A and 44B and the
tubular section 48. Outside this tubular section 48 is provided an
actuator 22 to selectively shift the magnetic substance 20 between
the high temperature side pipe 44A and the low temperature side
pipe 44B. In addition, permanent magnets 50 are arranged on both
sides of the high temperature side pipe 44A where the tubular
section 48 is extended, and by these permanent magnets 50, a
magnetic field can be applied to the magnetic substance 20 inside
the tubular section 48. Accordingly, the high temperature side and
the low temperature side of the tubular section 48, which is
applied a magnetic field from the permanent magnet 50, is
determined as the exothermic unit 12A and the endothermic unit 12B
of the magnetic refrigeration unit 12.
[0045] In the structure of the magnetic refrigeration unit 12 shown
in FIG. 2, the evaporated cooling refrigerant is circulated in the
pipe 42 and the magnetic cooling refrigerant is circulated in the
pipe 44, and the magnetic cooling refrigerant is refrigerated by
the evaporated cooling refrigerant at the connection 8. This cooled
refrigerant is circulated from the high temperature side pipe 44A
to the low temperature side pipe 44B. At the high temperature side
pipe 44A, when the magnetic substance 20 is shifted to the
exothermic section 12A of the high temperature side of the tubular
section 48, the magnetic substance 20 is exothermic due to the
application of magnetic field and conducts heat exchange between
the magnetic cooling refrigerant. Along with the heat dissipation
of the magnetic substance 20, the temperature of the magnetic
cooling refrigerant increases. However, since the magnetic cooling
refrigerant is cooled in advance, the magnetic cooling refrigerant
maintains a relatively low temperature while being circulated in
the low temperature side pipe 44B. When the magnetic substance 20
is shifted to the endothermic unit 12B of the low temperature side
of the tubular section 48, the magnetic substance 20 applies an
endothermic effect to the magnetic cooling refrigerant. The
sufficiently cooled magnetic cooling refrigerant is supplied to the
heat exchanger 16 via the low temperature side pipe 44B.
[0046] In the structure shown in FIG. 2, the connection 8 is
illustrated with a pair of permanent magnets 50 arranged in two
places, and a tubular section 48 is arranged between the pair of
permanent magnets 50. However, it is obvious that a plurality of
connections 8 may be provided, or a combination of a permanent
magnet 50 and a tubular section 48 may be arranged in a plurality
of places so that a plurality of endothermic units 12B are provided
to the low temperature side pipe 44B to further cool the magnetic
cooling refrigerant to a lower temperature. Alternatively, as is
obvious from the arrangement in FIG. 2, an electromagnet may be
provided instead of the permanent magnet 50. Further, it is
preferable that a heat insulation zone 24 is provided between the
high temperature section and low temperature side pipes 44A and 44B
so that heat is not transferred to both sides.
[0047] Meanwhile, when the magnetic substance 20 has a negative
magnetic effect instead of the magnetic substance 20 having the
positive magnetic effect, it is obvious that the permanent magnet
50 or the electromagnet is provided on the low temperature side
pipe 44B. There is no constraint on the time cycle for applying or
eliminating a magnetic field to the magnetic substance 20,
therefore, it may be determined appropriately in accordance with
the cooling characteristics realized at the magnetic refrigeration
cycle 10. Alternatively, without providing an independent actuator
22, the magnetic substance 20 may be shifted by utilizing the
piston of the compressor 3 used in the vapor compression
refrigeration cycle or a mechanical movement of a cylinder or some
kind of mechanical movement.
[0048] In the hybrid magnetic refrigerator shown in FIGS. 1 and 2,
refrigeration in a lower temperature can be realized by cooling the
refrigerant of the magnetic refrigeration cycle by the vapor
compression refrigeration cycle and further by the magnetic
refrigeration cycle. In comparison to the case where similar
refrigeration is realized by only the magnetic refrigeration cycle,
because the refrigerant circulating inside the magnetic
refrigeration cycle is cooled in advance, the magnetic refrigerator
can be made compact.
[0049] FIG. 3 schematically shows the hybrid magnetic refrigerator
according to another embodiment of the present invention. In FIG.
3, same symbols will be given and explanations will be omitted for
sections and devices equivalent to those shown in FIG. 1.
[0050] In the vapor compression refrigeration cycle 1 in the hybrid
magnetic refrigerator shown in FIG. 3, a receiver 6 to store a
liquefied refrigerant is provided between the condenser 4 and the
expansion valve 5. In other words, the refrigerant is compressed
and liquefied at the compressor 3 and is temporary stored in the
receiver 6 after heat is released from the liquefied refrigerant at
the condenser 4. The liquefied refrigerant is supplied to the
expansion valve 5 from this receiver 6 and is expanded and
vaporized. The vaporized refrigerant is supplied to the evaporator
2, where it deprives heat from the periphery of the evaporator
2.
[0051] In the hybrid magnetic refrigerator shown in FIG. 3, the
evaporator 2 of the vapor compression refrigeration cycle 1 and the
heat exchanger 11 of the magnetic refrigeration cycle are provided
in the connection 8. The heat exchanger 11 of the magnetic
refrigeration cycle is cooled by the evaporator 2 of the vapor
compression refrigeration cycle 1. Furthermore, the heat exchanger
11 of this magnetic refrigeration cycle is provided on the high
temperature side of the magnetic refrigeration cycle.
[0052] In the magnetic refrigeration cycle 30 shown in FIG. 3, the
refrigerant from the pump 32 is divided into two refrigerant
channels; one on the low temperature side and the other on the high
temperature side, at a branch section. Then, the refrigerant merges
again at the merging section and returns to the pump 32. In the
refrigerant channel on the low temperature side, the endothermic
unit 12B of the magnetic refrigeration unit 12 is provided. The
refrigerant is supplied via this endothermic section 12B to the
heat exchanger 16, which deprives the external environment of heat,
and is again returned to the pump 32. Meanwhile, in the refrigerant
channel on the high temperature side, the exothermic unit 12A of
the magnetic refrigeration unit 12 is provided. Heat is transferred
to the refrigerant from the magnetic substance 20 at the exothermic
unit 12A. The refrigerant passed through the exothermic unit 12A is
supplied to the heat exchanger 11 of the magnetic refrigeration
cycle, is refrigerated by the evaporator 2 of the vapor compression
refrigeration cycle 1 and is returned in similar fashion to the
pump 32.
[0053] The magnetic refrigeration unit 12 shown in FIG. 3 does not
have the pipe 44 for magnetic cooling refrigerant formed in a
horse-shoe shape in the structure shown in FIG. 2. However, it can
be realized by arranging the high temperature side pipe 44A and the
low temperature side pipe 44B in parallel. In other words, the
refrigerant from the pump 14 is split and supplied to the high
temperature side pipe 44A and low temperature side pipe 44B
respectively, are again merged and returned to the pump 14. As
shown in FIG. 3, likewise the magnetic refrigeration cycle shown in
FIGS. 1 and 2, when the magnetic substance 20 having a positive
magnetic effect is combined in the magnetic refrigeration unit 12,
the magnet device 18 is arranged on the high temperature side of
the magnetic refrigeration cycle. However, when the magnetic
substance 20 possesses a negative magnetic effect, the magnet
device 18 is arranged on the low temperature side of the magnetic
refrigeration cycle 10.
[0054] In the hybrid magnetic refrigerator shown in FIG. 3,
refrigeration in a lower temperature can be realized by cooling the
refrigerant of the magnetic refrigeration cycle at the vapor
compression refrigeration cycle and further at the magnetic
refrigeration cycle. In comparison to the case where similar
refrigeration is realized by only the magnetic refrigeration cycle,
because the refrigerant circulating inside the magnetic
refrigeration cycle is cooled in advance, the magnetic refrigerator
can be made compact.
[0055] As mentioned above, according to the present invention, a
hybrid magnetic refrigerator which is compact, highly efficient,
can refrigerate down to a low temperature region and can be used
for household, domestic and business purposes is provided.
[0056] Additional advantages and modifications will readily occur
to those skilled in the art. Therefore, the invention in its
broader aspects is not limited to the specific details and
representative embodiments shown and described herein. Accordingly,
various modifications may be made without departing from the spirit
or scope of the general inventive concept as defined by the
appended claims and their equivalents.
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