U.S. patent application number 13/509371 was filed with the patent office on 2012-09-06 for combined-loop magnetic refrigeration system.
Invention is credited to Serdar Celik, Chris Euler, Mehmet Hamdi Kural.
Application Number | 20120222428 13/509371 |
Document ID | / |
Family ID | 43991922 |
Filed Date | 2012-09-06 |
United States Patent
Application |
20120222428 |
Kind Code |
A1 |
Celik; Serdar ; et
al. |
September 6, 2012 |
COMBINED-LOOP MAGNETIC REFRIGERATION SYSTEM
Abstract
A magnetic refrigeration system having a magnetocaloric material
for adjusting the temperature of a transfer fluid is disclosed. The
magnetic refrigeration system includes tubing filled with the
transfer fluid that flows in a first pass through a heat exchanger
having a magnetocaloric material that is magnetized by one or more
electromagnets and heats the transfer fluid. The magnetocaloric
material is magnetized and demagnetized by one or more
electromagnets controlled by a timer/controller device. A three-way
solenoid valve controls the flow of heated transfer fluid from the
heat exchanger and directs the heated transfer fluid to a warm heat
exchanger for cooling of the transfer fluid. The cooled transfer
fluid is then passed a second time through the heat ex changer in
which the magnetocaloric material is demagnetized for further
cooling of the cooled transfer fluid.
Inventors: |
Celik; Serdar;
(Edwardsville, IL) ; Euler; Chris; (Edwardsville,
IL) ; Kural; Mehmet Hamdi; (Edwardsville,
IL) |
Family ID: |
43991922 |
Appl. No.: |
13/509371 |
Filed: |
August 2, 2010 |
PCT Filed: |
August 2, 2010 |
PCT NO: |
PCT/US10/44079 |
371 Date: |
May 11, 2012 |
Current U.S.
Class: |
62/3.1 |
Current CPC
Class: |
F28F 7/02 20130101; F25B
2600/01 20130101; F28F 21/08 20130101; F28D 7/106 20130101; F28D
9/0043 20130101; F25B 2321/002 20130101; Y02B 30/00 20130101; F25B
21/00 20130101; F28C 3/16 20130101; Y02B 30/66 20130101; F28D 7/06
20130101 |
Class at
Publication: |
62/3.1 |
International
Class: |
F25B 21/00 20060101
F25B021/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 11, 2009 |
US |
61260138 |
Claims
1. A magnetic refrigeration system comprising: a transfer fluid
that flows through a tubing in communication with a brazed heat
exchanger, the brazed heat exchanger including alternating layers
consisting of the tubing and a magnetocaloric material; one or more
electromagnets being operative for magnetizing and demagnetizing
the magnetocaloric material, a controller device controls the
operation of the one or more electromagnets such that the transfer
fluid is heated in a first pass through the brazed heat exchanger
when the magnetocaloric material is magnetized by the one or more
electromagnets and cooled in a second pass through the brazed heat
exchanger when the magnetocaloric material is demagnetized; a warm
heat exchanger in selective fluid flow communication with the
brazed heat exchanger for transferring heat from the transfer fluid
after the first pass of the transfer fluid through the brazed heat
exchanger; a cold heat exchanger cools a refrigerator cabinet when
the transfer fluid flowing through the cold heat exchanger provides
a cooling effect to the interior of the refrigerator cabinet after
the second pass of the transfer fluid through the brazed heat
exchanger; and a three-way valve for directing the flow of transfer
fluid from the brazed heat exchanger to either the warm heat
exchanger during the first pass of the transfer fluid or the cold
heat exchanger during the second pass of the transfer fluid as one
cycle of the magnetic refrigeration system is completed.
2. The magnetic refrigeration system of claim 1, wherein the
transfer fluid is water, a water-ethylene glycol mixture, or a
helium gas.
3. The magnetic refrigeration system of claim 1, further
comprising: a circulation pump for circulating fluid flow of the
transfer fluid through the tubing;
4. The magnetic refrigeration system of claim 1, wherein the
magnetocaloric material generates a magnetocaloric effect when the
one or more electromagnets magnetizes and demagnetizes the
magnetocaloric material.
5. The magnetic refrigeration system of claim 1, wherein the one or
more electromagnets generate a magnetic field in the range of
between 0.5-10 Tesla.
6. The magnetic refrigeration system of claim 1, wherein the
three-way valve is a solenoid valve.
7. The magnetic refrigeration system of claim 1, wherein the
three-way valve includes a cold fluidic outlet in selective fluid
flow communication with the cold heat exchanger.
8. The magnetic refrigeration system of claim 1, wherein the
three-way valve includes a warm fluidic outlet in selective fluid
flow communication with the warm heat exchanger.
9. The magnetic refrigeration system of claim 1, further comprising
at least one one-way valve for preventing flow of the transfer
fluid directly from the warm heat exchanger to the cool heat
exchanger
10. The magnetic refrigeration system of claim 1, wherein the
refrigeration cabinet is exposed to an outside ambient
temperature.
11. The magnetic refrigeration system of claim 10, wherein the
ambient temperature is about 25 degrees Celsius.
12. The magnetic refrigeration system of claim 1, wherein the
transfer fluid is heated during the first pass to a temperature
range of between 25.1-26.0 degrees Celsius.
13. The magnetic refrigeration system of claim 1, wherein the
transfer fluid is cooled during a second pass to a temperature
range of between 24.0-24.9 degrees Celsius.
14. The magnetic refrigeration system of claim 1, wherein the
refrigeration cabinet is cooled down to a temperature range of
between 19.0 to 23.0 degrees Celsius.
15. The magnetic refrigeration system of claim 1, further
comprising: A timer/controller component for controlling the
operation of the three-way valve such that either the warm fluidic
outlet is in fluid flow communication with the warm heat exchanger
or the cold fluidic outlet is in fluid flow communication with the
warm heat exchanger.
16. A magnetic refrigeration system comprising: a transfer fluid
that flows through a tubing in communication with a brazed heat
exchanger, the brazed heat exchanger including alternating layers
of the tubing and a magnetocaloric foam, the magnetocaloric foam
containing a magnetocaloric material; one or more electromagnets
being operative for magnetizing and demagnetizing the
magnetocaloric material contained in the magnetocaloric foam, a
controller device controls the operation of the one or more
electromagnets such that the transfer fluid is heated in a first
pass through the brazed heat exchanger when the magnetocaloric
material in the magnetocaloric foam is magnetized by the one or
more electromagnets and cooled in a second pass through the brazed
heat exchanger when the magnetocaloric material in the
magnetocaloric foam is demagnetized; a circulation pump for
circulating fluid flow of the transfer fluid through the tubing; a
warm heat exchanger in selective fluid flow communication with the
brazed heat exchanger for transferring heat from the transfer fluid
after the first pass of the transfer fluid through the brazed heat
exchanger; a cold heat exchanger cools a refrigerator cabinet when
the transfer fluid flowing through the cold heat exchanger provides
a cooling effect to the interior of the refrigerator cabinet after
the second pass of the transfer fluid through the brazed heat
exchanger; and a three-way valve for directing the flow of transfer
fluid from the brazed heat exchanger to either the warm heat
exchanger during the first pass of the transfer fluid or the cold
heat exchanger during the second pass of the transfer fluid as one
cycle of the magnetic refrigeration system is completed.
17. A magnetic refrigeration system comprising: a transfer fluid
that flows through a tubing in communication with a brazed heat
exchanger, the brazed heat exchanger including an enclosure in
communication with the tubing, the enclosure being filled with a
magnetocaloric foam in which the transfer fluid flows through, the
magnetocaloric foam containing a magnetocaloric material; one or
more electromagnets being operative for magnetizing and
demagnetizing the magnetocaloric material contained in the
magnetocaloric foam, a controller device controls the operation of
the one or more electromagnets such that the transfer fluid is
heated in a first pass through the brazed heat exchanger when the
magnetocaloric material in the magnetocaloric foam is magnetized
and cooled in a second pass through the brazed heat exchanger when
the magnetocaloric material contained in the magnetocaloric foam is
demagnetized; a circulation pump for circulating fluid flow of the
transfer fluid through the tubing; a warm heat exchanger in
selective fluid flow communication with the brazed heat exchanger
for transferring heat from the transfer fluid after the first pass
of the transfer fluid through the brazed heat exchanger; a cold
heat exchanger cools a refrigerator cabinet when transfer fluid
flowing through the cold heat exchanger for provides a cooling
effect to the interior of the refrigerator cabinet after the second
pass of the transfer fluid through the brazed heat exchanger; and a
three-way valve for directing the flow of transfer fluid from the
brazed heat exchanger to either the warm heat exchanger during the
first pass of transfer fluid or the cold heat exchanger during the
second pass of the transfer fluid as one cycle of the magnetic
refrigeration system is completed.
18. A magnetic refrigeration system comprising: a transfer fluid
that flows through a tubing in communication with a coaxial heat
exchanger, the coaxial heat exchanger including tubing defining an
inner tube surrounded by an outer tube, wherein the outer tube is
filled with a transfer fluid and the inner tube is filled with a
magnetocaloric material; one or more electromagnets being operative
for magnetizing and demagnetizing the magnetocaloric material, a
controller device controls the operation of the one or more
electromagnets such that the transfer fluid is heated in a first
pass through the coaxial heat exchanger when the magnetocaloric
material is magnetized by the one or more electromagnets and cooled
in a second pass through the coaxial heat exchanger when the
magnetocaloric material is demagnetized; a circulation pump for
circulating fluid flow of the transfer fluid through the tubing; a
warm heat exchanger in selective fluid flow communication with the
coaxial heat exchanger for transferring heat from the transfer
fluid after the first pass of the transfer fluid through the
coaxial heat exchanger; a cold heat exchanger cools a refrigerator
cabinet when the transfer fluid flowing through the cold heat
exchanger provides a cooling effect to the interior of the
refrigerator cabinet after the second pass of the transfer fluid
through the coaxial heat exchanger; and a three-way valve for
directing the flow of transfer fluid from the coaxial heat
exchanger to either the warm heat exchanger during the first pass
of the transfer fluid or the cold heat exchanger during the second
pass of the transfer fluid as one cycle of the magnetic
refrigeration is completed.
19. A magnetic refrigeration system comprising: a transfer fluid
that flows through a tubing in communication with a U-tube heat
exchanger, the U-tube heat exchanger including an enclosure that
encases U-shaped tubing filled with a magnetocaloric material, a
plurality of baffles being spaced within the enclosure to guide the
flow of transfer fluid through the U-tube heat exchanger; one or
more electromagnets being operative for magnetizing and
demagnetizing the magnetocaloric material, a controller controls
the operation of the one or more electromagnets such that the
transfer fluid is heated in a first pass through the U-tube heat
exchanger when the magnetocaloric material is magnetized by the one
or more electromagnets and cooled in a second pass through the
U-tube heat exchanger when the magnetocaloric material is
demagnetized; a circulation pump for circulating fluid flow of the
transfer fluid through the tubing; a warm heat exchanger in
selective fluid flow communication with the U-tube heat exchanger
for transferring heat from the transfer fluid after the first pass
of the transfer fluid through the U-tube heat exchanger; a cold
heat exchanger cools a refrigerator cabinet when the transfer fluid
flowing through the cold heat exchanger provides a cooling effect
to the interior of the refrigerator cabinet after the second pass
of the transfer fluid through the U-tube heat exchangers; and a
three-way valve for directing the flow of transfer fluid from the
U-tube heat exchanger to either the warm heat exchanger during the
first pass of the transfer fluid or the cold heat exchanger during
the second pass of the transfer fluid as one cycle of the magnetic
refrigeration system is completed.
20. A magnetic refrigeration system comprising: a transfer fluid,
that flows through a tubing in communication with a fluidized bed,
the fluidized bed including a packed bed in communication with the
tubing, the packed bed including membranes and a magnetocaloric
material for mixing with the transfer fluid as the transfer fluid
flows through the pack bed; one or more electromagnets being
operative for magnetizing and demagnetizing the magnetocaloric
material; controls the operation of the one or more electromagnets
such that the transfer fluid is heated in a first pass through the
fluidized bed when the magnetocaloric material is magnetized by the
one or more electromagnets and cooled in a second pass through the
fluidized bed when the magnetocaloric material is demagnetized; a
circulation pump for circulating fluid flow of the transfer fluid
through the tubing; a warm heat exchanger in selective fluid flow
communication with the fluidized bed for transferring heat from the
transfer fluid after the first pass of the transfer fluid through
the fluidized bed; a cold heat exchanger cools with a refrigerator
cabinet when the transfer flowing through the fluidized bed
provides a cooling effect to the interior of the refrigerator
cabinet after the second pass of the transfer fluid through the
fluidized bed; and a three-way valve for directing the flow of
transfer fluid from the fluidized bed to either the warm heat
exchanger or the cold heat exchanger after the second pass of the
transfer fluid as one cycle of the magnetic refrigeration is
completed.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims benefit of U.S. Provisional
Application No. 61/260,138 filed on Nov. 11, 2009.
FIELD
[0002] This document relates to a magnetic refrigeration system,
and more particularly to a magnetic refrigeration system for
generating a magnetocaloric effect that changes the temperature of
a transfer fluid for cooling a magnetic refrigerator.
BACKGROUND
[0003] It is well known in refrigeration technology to employ a gas
compression and expansion cycle arrangement to generate the
necessary cooling effect inside a refrigerator in a room
temperature environment. However, refrigeration technology that
relies on a gas compression and expansion cycle arrangement raises
issues related to environmental destruction caused by the use of
particular Freon gases as well as CFC substitutes that can be
discharged into the environment.
[0004] In recent years magnetic refrigeration technology has shown
great promise because of its environmental-friendliness and high
efficiency relative to the conventional gas compression and
expansion cycle arrangement of prior refrigeration technology. In
particular, magnetic refrigeration technology relies on a
magnetocaloric effect. The magnetocaloric effect is a phenomenon in
which the temperature of a magnetocaloric material changes in
accordance with a changing external magnetic field being applied by
a magnet to magnetize or demagnetize the magnetocaloric material.
In the late twentieth century, a magnetic refrigeration system
called an Active Magnetic Refrigeration System that uses a
magnetocaloric material for cooling a refrigerator in a room
temperature environment was developed. Magnetic refrigeration based
on this type of magnetocaloric system required that a magnetic
field generated by a magnet be applied to a magnetocaloric material
that is heated when magnetized such that thermal energy is
transferred to the adjacent area by a transfer fluid that flows
through adjacent tubing. Although the prior art magnetic
refrigeration systems have been successful, there is still a need
in the art for further improvements and advances that promote
greater efficiencies in magnetic refrigeration technology.
SUMMARY
[0005] In an embodiment, a magnetic refrigeration system may
include a transfer fluid that flows through tubing in communication
with a brazed heat exchanger. The brazed heat exchanger has
alternating layers of tubing and magnetocaloric material. One or
more electromagnets are operative for magnetizing and demagnetizing
the magnetocaloric material. A controller controls the operation of
one or more electromagnets such that the transfer fluid is heated
in a first pass through the brazed heat exchanger when the
magnetocaloric material is magnetized by one or more electromagnets
and then the transfer fluid is cooled in a second pass through the
brazed heat exchanger when the magnetocaloric material is
demagnetized. A circulation pump is provided for circulating fluid
flow of the transfer fluid through the tubing. In addition, a warm
heat exchanger is in selective fluid flow communication with the
brazed heat exchanger for transferring heat from the transfer fluid
after the first pass of the transfer fluid through the brazed heat
exchanger. A cold heat exchanger cools a refrigerator cabinet when
the transfer fluid flowing through the cold heat exchanger provides
a cooling effect to the interior of the refrigerator cabinet after
the second pass through the brazed heat exchanger. A three-way
valve is provided for directing the flow of transfer fluid from the
brazed heat exchanger to either the warm heat exchanger during the
first pass of the transfer fluid or the cold heat exchanger during
the second pass of the transfer fluid as one cycle of the magnetic
refrigeration system is completed.
[0006] In another embodiment, a magnetic refrigeration system may
include a transfer fluid that flows through tubing in communication
with a brazed heat exchanger. The brazed heat exchanger has
alternating layers of tubing and a magnetocaloric foam containing a
magnetocaloric material. One or more electromagnets are operative
for magnetizing and demagnetizing the magnetocaloric material
contained in the magnetocaloric foam. A controller device controls
the operation of one or more electromagnets such that the transfer
fluid is heated in a first pass through the brazed heat exchanger
when the magnetocaloric material contained in the magnetocaloric
foam is magnetized by one or more electromagnets and then the
transfer fluid is cooled in a second pass through the brazed heat
exchanger when the magnetocaloric material in the magnetocaloric
foam is demagnetized. A circulation pump is provided for
circulating fluid flow of the transfer fluid through the tubing. In
addition, a warm heat exchanger is in selective fluid flow
communication with the brazed heat exchanger for transferring heat
from the transfer fluid after the first pass of the transfer fluid
through the brazed heat exchanger. A cold heat exchanger cools a
refrigerator cabinet when the transfer fluid flowing through the
cold heat exchanger provides a cooling effect to the interior of
the refrigerator cabinet after the second pass of the transfer
fluid through the brazed heat exchanger. A three-way valve is
provided for directing the flow of transfer fluid from the brazed
heat exchanger to either the warm heat exchanger during the first
pass of the transfer fluid or the cold heat exchanger during the
second pass of the transfer fluid as one cycle of the magnetic
refrigeration system is completed.
[0007] In yet another embodiment, a magnetic refrigeration system
may include a transfer fluid that flows through tubing in
communication with a brazed heat exchanger. The brazed heat
exchanger includes an enclosure filled with magnetocaloric foam
containing a magnetocaloric material in communication with the
tubing in which the transfer fluid flows through. One or more
electromagnets are operative for magnetizing and demagnetizing the
magnetocaloric material contained in the magnetocaloric foam. A
controller device controls the operation of one or more
electromagnets such that the transfer fluid is heated during a
first pass through the brazed heat exchanger when the
magnetocaloric material in the magnetocaloric foam is magnetized
and cooled in a second pass through the brazed heat exchanger when
the magnetocaloric material contained in the magnetocaloric foam is
demagnetized. A circulation pump is provided for circulating fluid
flow of the transfer fluid through the tubing. In addition, a warm
heat exchanger is in selective fluid flow communication with the
brazed heat exchanger for transferring heat from the transfer fluid
after the first pass of the transfer fluid through the brazed heat
exchanger. A cold heat exchanger cools a refrigerator cabinet when
the transfer fluid flowing through the cold heat exchanger provides
a cooling effect to the interior of the refrigerator cabinet after
the second pass of the transfer fluid through the brazed heat
exchanger. A three-way valve is provided for directing the flow of
transfer fluid from the brazed heat exchanger to either the warm
heat exchanger during the first pass of the transfer fluid or the
cold heat exchanger during the second pass of the transfer fluid as
one cycle of the magnetic refrigeration system is completed.
[0008] In a further embodiment, a magnetic refrigeration system may
include a transfer fluid that flows through tubing being in
communication with a coaxial heat exchanger. The coaxial heat
exchanger includes tubing having an inner tube surrounded by an
outer tube, wherein the outer tube is filled with a transfer fluid
and the inner tube has a magnetocaloric material. One or more
electromagnets are operative for magnetizing and demagnetizing the
magnetocaloric material. A controller device controls the operation
of one or more electromagnets such that the transfer fluid is
heated during a first pass through the coaxial heat exchanger when
the magnetocaloric material is magnetized and cooled during a
second pass through the coaxial heat exchanger when the
magnetocaloric material is demagnetized. A circulation pump is
provided for circulating fluid flow of the transfer fluid through
the tubing. In addition, a warm heat exchanger is in selective
fluid flow communication with the coaxial heat exchanger for
transferring heat from the transfer fluid after the first pass
through the coaxial heat exchanger. A cold heat exchanger cools a
refrigerator cabinet when the transfer fluid flowing through the
cold heat exchanger provides a cooling effect to the interior of
the refrigerator cabinet after the second pass of the transfer
fluid through the coaxial heat exchanger. A three-way valve is
provided for directing the flow of transfer fluid from the coaxial
heat exchanger to either the warm heat exchanger during the first
pass of the transfer fluid or the cold heat exchanger during the
second pass of the transfer fluid after one cycle of the magnetic
refrigeration system is completed.
[0009] In another embodiment, a magnetic refrigeration system may
include a transfer fluid that flows through tubing in communication
with a U-tube heat exchanger. The U-tube heat exchanger includes an
enclosure that encases U-shaped tubing having a magnetocaloric
material with a plurality of baffles spaced within the interior of
the enclosure to guide the flow of transfer fluid through the
enclosure of the U-tube heat exchanger. One or more electromagnets
are in operative for magnetizing and demagnetizing the
magnetocaloric material. A controller device controls the operation
of one or more electromagnets such that the transfer fluid is
heated in a first pass through the U-tube heat exchanger when the
magnetocaloric material is magnetized by one or more electromagnets
and then cooled in a second pass through the U-tube heat exchanger
when the magnetocaloric material is demagnetized. A circulation
pump is provided for circulating fluid flow of the transfer fluid
through the tubing. In addition, a warm heat exchanger is in
selective fluid flow communication with the U-tube heat exchanger
for transferring heat from the transfer fluid after the first pass
of the transfer fluid through the U-tube heat exchanger. A cold
heat exchanger cools a refrigerator cabinet when the transfer fluid
flowing through the cold heat exchanger provides a cooling effect
to the interior of the refrigerator cabinet after the second pass
of the transfer fluid through the coaxial heat exchanger. A
three-way valve is provided for directing the flow of transfer
fluid from the U-tube heat exchanger to either the warm heat
exchanger during the first pass of the transfer fluid or the cold
heat exchanger during the second pass of the transfer fluid as one
cycle of the magnetic refrigeration system is completed.
[0010] In one other embodiment, a magnetic refrigeration system may
include a transfer fluid that flows through tubing in communication
with a fluidized bed. The fluidized bed includes a packed bed in
fluid flow communication with the tubing. The packed bed includes
one or more membranes and a magnetocaloric material for mixing with
the transfer fluid as the transfer fluid flows through the pack
bed. One or more electromagnets are operative for magnetizing and
demagnetizing the magnetocaloric material. A controller controls
the operation of one or more electromagnets such that the transfer
fluid is heated in a first pass of the transfer fluid through the
fluidized bed when the magnetocaloric material is magnetized and
cooled in a second pass of the transfer fluid through the fluidized
bed when the magnetocaloric material is demagnetized. A circulation
pump is provided for circulating fluid flow of the transfer fluid
through the tubing. In addition, a warm heat exchanger is in
selective fluid flow communication with the fluidized bed for
transferring heat from the transfer fluid after the first pass of
the transfer fluid through the fluidized bed. A cold heat exchanger
cools a refrigerator cabinet when the transfer fluid provides a
cooling effect to the interior of the refrigerator cabinet after
the second pass of the transfer fluid through the fluidized bed. A
three-way valve is provided for directing the flow of transfer
fluid from the fluidized bed to either the warm heat exchanger
during the first pass of the transfer fluid or the cold heat
exchanger during the second pass of the transfer fluid as one cycle
of the magnetic refrigeration system is completed.
[0011] Additional objectives, advantages and novel features will be
set forth in the description which follows or will become apparent
to those skilled in the art upon examination of the drawings and
detailed description which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a perspective view of a first embodiment for the
magnetic refrigeration system;
[0013] FIG. 2 is a simplified illustration of the first embodiment
for the magnetic refrigeration system showing the fluid pathway of
the transfer fluid within the system;
[0014] FIG. 3 is a simplified illustration of a brazed heat
exchanger for the first embodiment of the magnetic refrigeration
system;
[0015] FIG. 4 is a simplified illustration of the three-way
solenoid valve for the magnetic refrigeration system;
[0016] FIG. 5 is a simplified illustration of the check valve
arrangement for magnetic refrigeration system;
[0017] FIG. 6 is a perspective view of magnetocaloric foam
containing a magnetocaloric material used in a second embodiment of
the magnetic refrigeration system;
[0018] FIG. 7 is a simplified illustration of a brazed heat
exchanger including the magnetocaloric foam in alternating layers
for the second embodiment of the magnetic refrigeration system;
[0019] FIG. 8 is a simplified illustration of a brazed heat
exchanger having an enclosure filled with the magnetocaloric foam
for a third embodiment of the magnetic refrigeration system;
[0020] FIG. 9 is a simplified illustration of a coaxial heat
exchanger used with a fourth embodiment of the magnetic
refrigeration system;
[0021] FIG. 10 is a side view of the coaxial heat exchanger;
[0022] FIG. 10A is an enlarged end view of the coaxial heat
exchanger shown in FIG. 10;
[0023] FIG. 11 is a top view of the coaxial heat exchanger;
[0024] FIG. 12 is simplified illustration of a U-tube heat
exchanger used with a fifth embodiment of the magnetic
refrigeration system;
[0025] FIG. 13 is a simplified illustration of the U-Tube heat
exchanger;
[0026] FIG. 14 is a simplified illustration of a fluidized bed used
with a sixth embodiment of the magnetic refrigeration system;
and
[0027] FIG. 15 is a simplified illustration of the fluidized
bed.
[0028] Corresponding reference characters indicate corresponding
elements among the view of the drawings. The headings used in the
figures should not be interpreted to limit the scope of the
claims.
DETAILED DESCRIPTION
[0029] Referring to the drawings, one embodiment of the magnetic
refrigeration system is illustrated and generally indicated as 10
in FIGS. 1-3. A first embodiment of the magnetic refrigeration
system 10 includes a brazed heat exchanger 12 that heats a transfer
fluid 30 from ambient temperature, for example 25 degrees Celsius,
to a predetermined temperature range of between 25.1-26.0 degrees
Celsius in a first pass of the transfer fluid 30 through the brazed
heat exchanger 12 and then cools the transfer fluid 30 to another
predetermined temperature range of between 24.0-24.9 degrees
Celsius in a second pass of the transfer fluid 30 through the
brazed heat exchanger 12. The brazed heat exchanger 12 includes an
exchanger body 37 having a plurality of plates 43 therein, which
are vacuum brazed together to form alternate layers of plates 43
that define alternating channels 45A and 45B throughout the brazed
heat exchanger 12. As shown in FIG. 3, alternate channels 45A each
include a magnetocaloric material 28 and respective alternating
channels 45B are adapted for flow of the transfer fluid 30 through
each channel 45B to transfer thermal energy between the
magnetocaloric material 28 and transfer fluid 30 as shall be
discussed in greater detail below. As used herein, the term
"magnetocaloric material" shall mean any material that provides a
magnetocaloric effect such that a magneto-thermodynamic phenomenon
is generated in which a reversible change in temperature of a
suitable material is caused by exposing the material to a changing
magnetic field.
[0030] The brazed heat exchanger 12 includes a fluid inlet 38 for
permitting the ingress of transfer fluid 30 into the exchanger body
37 and a fluid outlet 40 for the egress of transfer fluid 30 from
the exchanger body 37. Hollow tubing 21 communicates with the fluid
inlet 38 and fluid outlet 40 of the brazed heat exchanger 12 for
transporting the transfer fluid 30 between various components
throughout the magnetic refrigeration system 10 as illustrated in
FIG. 2. In one embodiment, the transfer fluid 30 used within the
magnetic refrigeration system 10 may be water. In other
embodiments, the transfer fluid 30 may be a water-ethylene glycol
mixture, air, or helium.
[0031] Magnetic refrigeration system 10 also includes one or more
electromagnets 26, such as superconducting electromagnets, that
could yield a magnetic field in the range of between 0.5-10 Tesla.
In the first embodiment, the magnetic refrigeration system 10
includes a pair of electromagnets 24A and 24B that are oriented on
opposite sides of exchanger body 37 for magnetizing and
demagnetizing the magnetocaloric material 28 inside the brazed heat
exchanger 12 when the electromagnets 24A and 24B are activated and
deactivated by the magnetic refrigeration system 10. The
magnetocaloric material 28 contained in each channel 45A of the
brazed heat exchanger 12 is heated up to a predetermined
temperature when the pair of electromagnets 24A and 24B are
activated as the transfer fluid 30 makes the first pass through the
brazed heat exchanger 12. The heat generated by the magnetized
magnetocaloric material 28 inside channels 45A radiates and is
transferred to the transfer fluid 30 flowing inside adjacent
alternating channels 45B as the transfer fluid 30 flows from the
fluid inlet 38 and then exits the fluid outlet 40 of the brazed
heat exchanger 12.
[0032] Referring back to FIG. 2, after the heated transfer fluid 30
exits the fluid outlet 40 of the brazed heat exchanger 12 a
circulation pump 20 may continuously circulate the flow of transfer
fluid 30 to a solenoid valve 22 that guides the transfer fluid 30
to a warm heat exchanger 18 or cold heat exchanger 16. In one
embodiment, the solenoid valve 22 is a three-way solenoid valve 22
that permits the transfer fluid 30 to flow to either the warm heat
exchanger 18 after the transfer fluid 30 has been heated up by the
brazed heat exchanger 12 during the first pass by the transfer
fluid 30, or the cold heat exchanger 16 once the transfer fluid 30
has been cooled down after making the second pass through the
brazed heat exchanger 12.
[0033] Referring to FIG. 4, the solenoid valve 22 includes a
solenoid valve body 39 that defines a fluidic channel arrangement
42 with gates (not shown) that channel transfer fluid 30 to either
the warm heat exchanger 18 during the first pass or the cold heat
exchanger 16 during the second pass of the transfer fluid through
the brazed heat exchanger 12 as one cycle of the magnetic
refrigeration system 10 has been completed. For example, the
solenoid valve 22 may be similar to those valves used in heat pumps
and air conditioners. In particular, the fluidic channel 42 defines
a cold fluidic outlet 44 for transport of the transfer fluid 30 to
the cold heat exchanger 16 and a warm fluidic outlet 46 for
transport of the transfer fluid 30 to the warm heat exchanger 18.
The solenoid valve 22 is controlled by a timer/controller device 23
that operates the gates to control the flow of transfer fluid 30
through either the cold fluidic outlet 44 or warm fluidic outlet
46. As shown, warm fluid pathway 50 designates the flow of transfer
fluid 30 from the solenoid valve 20 to the warm heat exchanger 18,
while the cold fluid pathway 52 designates the flow of transfer
fluid 30 from the solenoid valve 20 to the cold heat exchanger 16
as shall be discussed in greater detail below.
[0034] Once the transfer fluid 30 has been heated up during the
first pass through the brazed heat exchanger 12 and is circulated
by the circulation pump 20, the heated transfer fluid 30 enters the
solenoid valve 22. As the transfer fluid 30 enters the solenoid
valve 22, the timer/controller device 23 controls the gates of the
valve 22 such that the transfer fluid 30 that enters the fluid
inlet 48 is made to exit through the warm fluid outlet 46 for
transport to the warm heat exchanger 18. The heated transfer fluid
30 entering the warm heat exchanger 18 is then cooled as the heat
contained in the transfer fluid 30 is transferred through the
tubing 21 of the warm heat exchanger 18. In one embodiment of the
warm heat exchanger 18, tubing 21 may have a U-tube configuration
that allows the heat contained in the transfer fluid 30 to be
readily and efficiently transferred through the tubing 21. The warm
heat exchanger 18 may include a circulation fan 32 to assist in
dissipating the radiated heat transferred from the heated transfer
fluid 30.
[0035] Referring to FIGS. 2 and 5, after exiting the warm heat
exchanger 18, the cooled transfer fluid 30 is directed back for a
second pass through the brazed heat exchanger 12 via a one-way
check valve 26A that permits one-way fluid flow through tubing 21
and into the fluid inlet 38 of the brazed heat exchanger 12 as
illustrated by the arrows that indicate fluid flow of transfer
fluid 30. Another one-way check valve 26B permits fluid flow only
from the cool heat exchanger 16 and prevents any transfer fluid 30
from flowing from the warm heat exchanger 18 to the cold heat
exchanger 16. The cooled transfer fluid 30 reenters the brazed heat
exchanger 30 during the second pass with the electromagnets 24A and
24B turned off by the timer/controller 23, thereby placing the
magnetocaloric material 28 in a demagnetized state. In the
demagnetized state, the magnetocaloric material 28 is cooled down
and is maintained at a temperature that is lower than the
temperature of the cooled transfer fluid 30 reentering the brazed
heat exchanger 12 from the warm heat exchanger 18. In one
embodiment, the temperature range of the cooled transfer fluid 30
that returns from the brazed heat exchanger 12 may be in a range of
between 24.5 to 25.5 degrees Celsius. As the cooled transfer fluid
30 travels through the brazed heat exchanger 12 the relatively
cooler temperature of the magnetocaloric material 28 surrounding
the flow of the cooled transfer fluid 30 transfers thermal energy
between the magnetocaloric material 28 and the transfer fluid 30,
thereby further reducing the temperature of the cooled transfer
fluid 30 as heat from the transfer fluid 30 is transferred to the
magnetocaloric material 28. At the outlet of the brazed heat
exchanger 12, the temperature of the transfer fluid 30 may be in
the range of between 24.0-24.9 degrees Celsius for the first
cycle.
[0036] Once the cooled transfer fluid 30 is further cooled down in
the brazed heat exchanger 12 during the second pass, the further
cooled transfer fluid 30 re-enters the solenoid valve 22 and the
timer/controller 23 switches the gates of the valve 22 such that
the transfer fluid 30 exits only through the cold fluid outlet 44
and enters the cold heat exchanger 16. The cold heat exchanger 16
cools the interior of a refrigeration cabinet 14 that is exposed to
the surrounding ambient temperature. For example, the refrigerator
cabinet 14 may be cooled down to a temperature range of between
19.0-23.0 degrees Celsius when the ambient temperature surrounding
the refrigerator cabinet 14 is about 25 degrees Celsius. In one
embodiment, the tubing 21 of the cold heat exchanger 16 has a
U-tube configuration such that the further cooled transfer fluid 30
flowing through tubing 21 provides a cooling effect by reducing the
temperature of the refrigeration cabinet 14 to a desired cool
temperature. After the further cooled transfer fluid 30 is
circulated through the cold heat exchanger 16, the transfer fluid
30 exits through the one-way check valve 26B and enters the brazed
heat exchanger 12 to begin the next cycle of the magnetic
refrigeration system 10.
[0037] In one embodiment of the magnetic refrigeration system 10,
the coefficient of performance using water as the transfer fluid 30
is 0.4 wherein the coefficient of performance for prior art
magnetic refrigeration system is in the range of between 0.05-0.5.
In addition, at an ambient temperature of 25 degrees Celsius, the
magnetic refrigeration system 10 can achieve a temperature within
the transfer fluid 30 of 21 degrees Celsius in the cold heat
exchanger and a temperature within the transfer fluid 30 of 27
degrees Celsius in the warm heat exchanger. As such, the
temperature of the transfer fluid 30 is reduced by 0.7 degrees
Celsius from the first pass to the second pass through the magnetic
refrigeration system 10.
[0038] Referring to FIGS. 6 and 7, a second embodiment of the
magnetic refrigeration system, designated 10A, is illustrated.
Magnetic refrigeration system 10A is substantially similar to the
first embodiment of the magnetic refrigeration system 10; however,
magnetic refrigeration system 10A includes a brazed heat exchanger
12A that replaces the magnetocaloric material 28 in a solid state
with a magnetocaloric foam material 34 that contains a
magnetocaloric material 28. The magnetocaloric foam 34 completely
fills a space to form alternating layers within the brazed heat
exchanger 12A that increases the heat transfer area of the
magnetocaloric material 28, thereby producing a higher rate of heat
transfer between the magnetocaloric material 28 and the transfer
fluid 30 flowing through tubing 21. The timer/controller device 23
also controls the magnetization and demagnetization of the
magnetocaloric material 28 in the magnetocaloric foam 34 in order
to adjust the temperature of the transfer fluid 30 through the
magnetic refrigeration system 10.
[0039] As shown in FIG. 7, the second embodiment of the brazed heat
exchanger 12A includes a body 37A that encases alternating U-shaped
layers of magnetocaloric foam 34 and U-shaped tubing 21 in which
the transfer fluid 30 flows through. The U-shaped tubing 21 inside
the brazed heat exchanger 12A communicates with an inlet 60 and an
outlet 62 for the ingress and egress of transfer fluid 30 through
the heat exchanger 12A. A pair of electromagnets 24A and 24B is
positioned on opposite sides of the body 37A for magnetizing and
demagnetizing the magnetocaloric material 28 in the magnetocaloric
foam 34 when actuated by the timer/controller device 23.
[0040] Referring to FIG. 8, a third embodiment of the magnetic
refrigeration system, designated 10B, is illustrated. Magnetic
refrigeration system 10B is substantially similar to the first
embodiment of the magnetic refrigeration system 10 with the
exception that a brazed heat exchanger 12B includes an enclosure 33
completely filled with the magnetocaloric foam 34 in which the
transfer fluid 30 flows through. The enclosure 33 of the brazed
heat exchanger 12B may include one or more fluid inlets 68 for the
ingress of transfer fluid 30 into the brazed heat exchanger 12B and
one or more fluid outlets 70 for the egress of transfer fluid 30
from the brazed heat exchanger 12B. As noted with the other
embodiments, the timer/controller device 23 controls the
magnetization and demagnetization of the magnetocaloric material
128 contained in the magnetocaloric foam 34 inside the enclosure 33
by the electromagnets 24A and 24B such that the temperature of as
the transfer fluid 30 is adjusted as fluid flows through the foam
34 that fills the inside of enclosure 33.
[0041] Referring to FIGS. 9-11, a fourth embodiment of the magnetic
refrigeration system, designated 10C, is illustrated. Magnetic
refrigeration system 10C replaces the brazed heat exchanger 12 of
the other embodiments with a coaxial heat exchanger 13 having
tubing 21 that defines an inner tube 55 filled with the
magnetocaloric material 28 surrounded by an outer tube 57 wherein
the transfer fluid 30 flows. Alternatively, the magnetocaloric
material 28 may fill the inner tube 55, while the transfer fluid 30
may flow through the outer tube 57. Electromagnets 24A and 24B may
be positioned in the axial space 63 defined by the coaxial heat
exchanger 13 or a plurality of electromagnets 24 may be positioned
around the tubing 21 surrounding the magnetocaloric material 28 in
order to adjust the temperature of the transfer fluid 30.
[0042] As shown in FIGS. 12 and 13, a fifth embodiment of the
magnetic refrigeration system, designated 10D, is illustrated.
Magnetic refrigeration system 10D includes a U-tube heat exchanger
15 having an enclosure 41 that encases U-shaped tubing 21 filled
with the magnetocaloric material 28. A plurality of baffles 56 may
be spaced between the fluid inlet 72 and fluid outlet 74 of the
enclosure 41. This arrangement of baffles 56 guides the flow of
transfer fluid 30 entering the fluid inlet 72 over a greater area
of the U-shaped tubing 21 within the enclosure 41 as illustrated by
fluid flow 51, thereby providing a greater transfer rate of thermal
energy between the magnetocaloric material 28 and the transfer
fluid 30.
[0043] Referring to FIGS. 14 and 15, a sixth embodiment of the
magnetic refrigeration system, designated 10E, is illustrated.
Magnetic refrigeration system 10E replaces the brazed heat
exchanger 12 of the other embodiment with a fluidized bed 17, which
allows direct contact between the magnetocaloric material 28 and
the transfer fluid 30. The fluidized bed 17, which is formed to
enable a solid-fluid mixture for improved heat transfer, includes a
packed bed 64 that defines an opening 65 for inflow of transfer
fluid 30 through the packed bed 64 from a fluid inlet 76 to a fluid
outlet 78. As the transfer fluid 30 enters the packed bed 64, the
magnetocaloric material 28 is mixed with the transfer fluid 30.
Membranes 66 contained inside the packed bed 64 prevents mixing of
the magnetocaloric material 28 with the transfer fluid 30 so that
the magnetocaloric material 28 does not become entrained with the
transfer fluid 30 as the fluid 30 exits the fluidized bed 17. The
membranes 66 may be elastic or rigid bodies, such as strainers used
in conventional refrigeration or plumbing system.
[0044] It should be understood from the foregoing that, while
particular embodiments have been illustrated and described, various
modifications can be made thereto without departing from the spirit
and scope of the invention as will be apparent to those skilled in
the art. Such changes and modifications are within the scope and
teachings of this invention as defined in the claims appended
hereto.
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