U.S. patent application number 13/134727 was filed with the patent office on 2011-12-22 for apparatus having agitator for agitating fluid.
This patent application is currently assigned to DENSO CORPORATION. Invention is credited to Kentarou Fukuda, Rie Fukuta, Yoshimasa Hijikata, Touru Kawaguchi, Yasunori Niiyama, Yoshiyasu Yamada, Shinichi Yatsuzuka.
Application Number | 20110308774 13/134727 |
Document ID | / |
Family ID | 45327644 |
Filed Date | 2011-12-22 |
United States Patent
Application |
20110308774 |
Kind Code |
A1 |
Fukuta; Rie ; et
al. |
December 22, 2011 |
Apparatus having agitator for agitating fluid
Abstract
An apparatus of a heat transfer circuit in which a heat transfer
fluid with small particles circulates includes a container and an
agitator. The container is located in a lower position of the
apparatus in a vertical direction and defines a chamber where the
heat transfer liquid passes when circulating in the heat transfer
circuit. The agitator is located in the chamber to agitate the heat
transfer fluid.
Inventors: |
Fukuta; Rie; (Nisshin-city,
JP) ; Hijikata; Yoshimasa; (Miyoshi-city, JP)
; Yatsuzuka; Shinichi; (Nagoya-city, JP) ; Yamada;
Yoshiyasu; (Chiryu-city, JP) ; Kawaguchi; Touru;
(Kariya-city, JP) ; Niiyama; Yasunori;
(Kuwana-city, JP) ; Fukuda; Kentarou;
(Kariya-city, JP) |
Assignee: |
DENSO CORPORATION
Kariya-city
JP
|
Family ID: |
45327644 |
Appl. No.: |
13/134727 |
Filed: |
June 15, 2011 |
Current U.S.
Class: |
165/109.1 |
Current CPC
Class: |
F28F 13/12 20130101;
H01L 23/473 20130101; H01L 2924/0002 20130101; H01L 2924/00
20130101; H01L 2924/0002 20130101; F28D 1/05366 20130101; F28F
2250/08 20130101 |
Class at
Publication: |
165/109.1 |
International
Class: |
F28F 13/12 20060101
F28F013/12 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 17, 2010 |
JP |
2010-138694 |
Claims
1. An apparatus of a heat transfer circuit in which a heat transfer
fluid with a solvent and a plurality of particles dispersed in the
solvent circulates to transfer heat generated by a heat source, the
solvent being water or organic solvent, the apparatus comprising: a
container located in a lower position of the apparatus in a
vertical direction and defining a chamber where the heat transfer
liquid passes to circulate in the heat transfer circuit; and an
agitator located in the chamber and configured to agitate the heat
transfer fluid.
2. The apparatus according to claim 1, wherein the apparatus is a
heat exchanger, a reserver tank, or a pipe of the heat transfer
circuit.
3. The apparatus according to claim 1, wherein the agitator
produces a vortex in a jet of the heat transfer liquid issuing into
the chamber in order to shake the jet.
4. The apparatus according to claim 3, wherein the container and
the agitator are a single piece, the container defines an inlet to
the chamber, and a height of the inlet is less than a height of the
chamber in the vertical direction so that the container serves as
the agitator.
5. The apparatus according to claim 1, wherein the container and
the agitator are a single piece, the container has a cylindrical
inner surface defining an inlet to the chamber, and the inlet
extends in a direction of the tangent to the cylindrical inner
surface of the container so that the container serves as the
agitator.
6. The apparatus according to claim 1, wherein the agitator
ultrasonically vibrates the heat transfer fluid.
7. The apparatus according to claim 1, wherein the agitator
includes a driven portion and a rotator that rotates with the
driven portion.
8. The apparatus according to claim 7, wherein the rotator is
positioned below the driven portion in the vertical direction, and
the driven portion is driven by the heat transfer liquid flowing
into the chamber.
9. The apparatus according to claim 7, wherein the driven portion
is driven by power supply from a starter of an engine or a motor of
a vehicle.
10. The apparatus according to claim 7, wherein the driven portion
is driven by power generated when a door of a vehicle is opened and
closed.
11. The apparatus according to claim 1, wherein the agitator
includes a cylindrical column, and the cylindrical column produces
a Karman vortex when the heat transfer fluid flowing into the
chamber hits the cylindrical column.
12. The apparatus according to claim 1, wherein the agitator
includes a film having a fixed end on one side and a free end on
the other side, and the free end of the film floats in the heat
transfer fluid when the heat transfer fluid flows into the
chamber.
13. The apparatus according to claim 1, wherein the agitator
includes an inlet passage for the heat transfer fluid to the
chamber, and the inlet passage extends obliquely downward toward
the chamber.
14. The apparatus according to claim 1, wherein the agitator
includes an inlet passage for the heat transfer fluid to the
chamber, and the inlet passage is connected to a bottom of the
container in such a manner that the heat transfer fluid flows
upward in the chamber.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is based on and claims priority to Japanese
Patent Application No. 2010-138694 filed on Jun. 17, 2010, the
contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to an apparatus having an
agitator for agitating a heat transfer fluid with small
particles.
BACKGROUND OF THE INVENTION
[0003] A heat transfer fluid is used to absorb heat from a heat
source and transfer the absorbed heat. For example, a heat transfer
fluid disclosed in JP-A-2007-31520 or US 2010/0095911 corresponding
to JP-A-2008-189901 is formed by adding nanoparticles with a
diameter on the order of nanometers to a solvent to improve a heat
conductivity of the heat transfer fluid.
[0004] Specifically, in JP-A-2007-31520, carbon nanotube of 0.05 wt
% or more and cellulose derivative or its sodium salt are added to
a solvent such as water or ethylene glycol. In US 2010/0095911,
carbon nanotube and carboxymethylcellulose sodium salt are added to
a solvent such as water or ethylene glycol.
[0005] There is a possibility that the nanoparticles can
precipitate out of the solvent with time or due to the cessation of
the flow of the heat transfer fluid. If the nanoparticles
precipitate out of the solvent, the heat conductivity of the heat
transfer fluid decrease.
SUMMARY OF THE INVENTION
[0006] In view of the above, it is an object of the present
invention to provide an apparatus having an agitator for agitating
a heat transfer fluid with small particles to prevent a decrease in
a heat conductivity of the heat transfer fluid.
[0007] According to an aspect of the present invention, an
apparatus of a heat transfer circuit in which a heat transfer fluid
with small particles circulates includes a container and an
agitator. The container is located in a lower position of the
apparatus in a vertical direction and defines a chamber where the
heat transfer liquid passes when circulating in the heat transfer
circuit. The agitator is located in the chamber to agitate the heat
transfer fluid.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The above and other objects, features, and advantages will
become more apparent from the following description and drawings in
which like reference numerals depict like elements. In the
drawings:
[0009] FIG. 1 is a block diagram of a heat transfer circuit
including an apparatus having an agitator according to a first
embodiment of the present invention;
[0010] FIG. 2 is a diagram illustrating a detailed view of the
agitator of the apparatus of FIG. 1;
[0011] FIGS. 3A-3D are diagrams illustrating a flow of a heat
transfer fluid caused by the agitator;
[0012] FIG. 4 is a diagram illustrating an apparatus having an
agitator according to a second embodiment of the present
invention;
[0013] FIG. 5 is a block diagram of a heat transfer circuit
including an apparatus having an agitator according to a third
embodiment of the present invention;
[0014] FIG. 6 is a diagram illustrating an apparatus having an
agitator according to a fourth embodiment of the present
invention;
[0015] FIG. 7 is a block diagram of a heat transfer circuit
including an apparatus having an agitator according to a fifth
embodiment of the present invention;
[0016] FIG. 8 is a diagram illustrating a detailed view of the
agitator of the apparatus of FIG. 7;
[0017] FIG. 9 is a diagram illustrating an agitator according to a
modification of the fifth embodiment;
[0018] FIGS. 10A-10C are diagrams illustrating operations of an
agitator according to a sixth embodiment of the present
invention;
[0019] FIG. 11 is a diagram illustrating an agitator according to a
seventh embodiment of the present invention, and
[0020] FIG. 12 is a diagram illustrating an agitator according to
an eighth embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
First Embodiment
[0021] A heat transfer circuit 1 according to a first embodiment of
the present invention is described below with reference to FIG. 1.
A heat transfer fluid circulates in the heat transfer circuit 1 and
transfers heat generated by a heat source such as an engine or a
transmission apparatus of a vehicle to outside, thereby cooling the
heat source. The heat transfer fluid includes a solvent and small
particles having heat conductivity greater than that of the
solvent. The particles are dispersed in the solvent so that the
heat transfer fluid can have a high heat conductivity. Therefore,
the heat transfer fluid can efficiently transfer the heat.
[0022] The solvent can carry the particles dispersed in the
solvent. For example, the solvent can be water or organic material
such as ethylene glycol or toluene. The solvent can be a
single-component substance or a mixture of components.
[0023] Each particle dispersed in the solvent is very small, for
example, on the order of micrometers or nanometers in size. For
example, the particle can be a metal particle made of gold (Au),
silver (Ag), copper (Cu), iron (Fe), or nickel (Ni). Alternatively,
the particle can be an inorganic particle made of silicon (Si) or
fluorine (F). Alternatively, the particle can be an oxide particle
made of aluminum oxide (Al.sub.2O.sub.3), magnesium oxide (MgO),
copper oxide (CuO), Ferric trioxide (Fe.sub.2O.sub.3), or titanium
oxide (TiO). Alternatively, the particle can be a polymer particle
made of carbon nanotube or resin.
[0024] The particle is not limited to a particular shape. For
example, the particle can have a rod-like shape, a spherical shape,
or a polyhedral shape. The rod-like shaped particle means a long
particle having a large aspect ratio, which is a ratio of the long
side (i.e., length) to the short side (i.e., width).
[0025] Referring to FIG. 1, the heat transport circuit 1 includes a
central processing circuit (CPU) 2, a heat exchanger (HEX) 3, a
radiator 4, a reserver tank 5, and a pump 6. The CPU 2, the heat
exchanger 3, the radiator 4, the reserver tank 5, and the pump 6
are connected in a ring to form the heat transfer circuit 1. The
CPU 2 is an example of a heat source.
[0026] Although not shown in the drawings, the heat exchanger 3 has
a heat exchange plate and a pipe extending around the heat exchange
plate. The heat transfer fluid passes the heat exchanger 3 by
flowing through the pipe. The heat exchange plate is thermally
connected to the CPU 2 so that heat generated by the CPU 2 can be
transferred to the heat exchange plate. When the heat transfer
fluid flows through the pipe, the heat transfer fluid comes into
thermal contact with the heat exchange plate so that the heat
transferred to the heat exchange plate can be absorbed by the heat
transfer fluid. Thus, the CPU 2 can be cooled. In the heat
exchanger 3, an inlet of the pipe is connected to the pump 6, and
an outlet of the pipe is connected to the radiator 4.
[0027] The radiator 4 includes a core 43, a lower tank 41, and an
upper tank 44. The core 43 has tubes and fins that are alternately
arranged with the tubes. The tubes connect the lower tank 41 and
the upper tank 44. The fins are in thermal contact with the tubes
to increase the surface areas of the tubes. The lower tank 41 has
an inlet pipe 42 connected to the heat exchanger 3. The heat
transfer fluid flows from the heat exchanger 3 to the radiator 4
through the inlet pipe 42 and is collected in the lower tank 41.
The heat transfer fluid collected in the lower tank 41 flows
through the pipes and is collected in the upper tank 44. The upper
tank 44 has an outlet pipe 45 connected to the reserver tank 5.
[0028] The reserver tank 5 is an auxiliary tank for storing the
heat transfer fluid circulating in the heat transfer circuit 1. An
inlet pipe 52 connected to the outlet pipe 45 of the radiator 4 is
connected to a lower part of the reserver tank 5 in a vertical
direction. An outlet pipe 53 connected to the pump 6 is connected
to the reserver tank 5. It is noted that the output pipe 53 is
located above the inlet pipe 52 in the vertical direction. The
reserver tank 5 has a bottom container 51 in a lower position in
the vertical direction.
[0029] The pump 6 is an electric pump and forces the heat transfer
fluid to circulate in the heat transfer circuit 1. When the pump 6
is activated, the heat transfer fluid circulates in the heat
transfer circuit 1 so as to cool the CPU 2. Specifically, the heat
transfer fluid pumped by the pump 6 flows to the heat exchanger 3
and absorbs the heat generated by the CPU 2 through the heat
exchange plate in the heat exchanger 3. Then, the heat transfer
fluid flows to the radiator 4 so that the absorbed heat can be
transferred to the radiator 4 by the heat transfer fluid. In the
radiator 4, when the heat transfer fluid flows from the lower tank
41 to the upper tank 44 through the tubes of the core 43, the heat
transfer fluid is cooled by dissipating the absorbed heat into the
air passing through the tubes and the fins of the core 43. The heat
transfer fluid cooled in the core 43 is collected in the upper tank
44, flows out to the reserver tank 5, and is sucked into the pump
6. The heat transfer fluid sucked into the pump 6 is pumped up to
the heat exchanger 3, absorbs the heat generated by the CPU 2 in
the heat exchanger 3, and then is cooled by dissipating the
absorbed heat into the air in the radiator 4. In this way, when the
pump 6 is in operation, the heat transfer fluid continuously
circulates in the heat transfer circuit 1 and repeats absorption
and dissipation of heat.
[0030] When the pump 6 is stopped, the flow of the heat transfer
fluid is stopped. As a result, there is a possibility that the
particles in the heat transfer fluid may solidify and precipitate
out of the solvent. Since the precipitation of the particles occurs
due to the fact that the heat transfer fluid is under the influence
of gravity, it is difficult to completely prevent the
precipitation. As mentioned previously, when the particles
precipitate out of the solvent, the heat conductivity of the heat
transfer fluid decreases compared to when the particles are
dispersed in the solvent. Therefore, even when the pump 6 is
reactivated under a condition where the particles precipitate out
of the solvent, absorption of heat in the heat exchanger 3 and
dissipation of heat in the radiator 4 are not suitably performed
due to a decrease in the heat conductivity of the heat transfer
fluid. As a result, a desired cooling performance cannot be
obtained in the heat transfer circuit 1.
[0031] It is likely that the precipitate of the particles remains
in the tubes and the containers of the apparatus of the heat
transfer circuit 1. Specifically, the precipitate can exist in the
inlet pipe 42, the outlet pipe 45, the inlet pipe 52, the output
pipe 53, the lower tank 41 of the radiator 4, and the bottom
container 51 of the reserver tank 5.
[0032] According to the first embodiment, an agitator 7 for
agitating the heat transfer fluid is provided in the container that
is located in a lower position in the vertical direction.
Specifically, in an example shown in FIG. 1, the agitator 7 is
provided in each of a chamber 71 of the lower tank 41 of the
radiator 4 and a chamber 71 of a bottom container 51 of the
reserver tank 5. That is, each of the radiator 4 and the reserver
tank 5 is an apparatus having an agitator for agitating a heat
transfer fluid with a solvent and small particles dispersed in the
solvent to prevent the particles from precipitating out of the
solvent.
[0033] FIG. 2 illustrates a detailed view of the lower tank 41
having the agitator 7. The lower tank 41 itself serves as the
agitator 7. That is, the lower tank 41 and the agitator 7 are a
single piece. The agitator 7 is configured as an oscillator for
producing vortexes VA, VB in a jet of the heat transfer fluid
issuing into the chamber 71 so as to swing the jet. The agitator 7
includes a chamber member (e.g., the lower tank 41) defining the
chamber 71, and a nozzle (e.g., the inlet pipe 42) defining an
inlet 72 to the chamber 71. It is noted that a height "a" of the
inlet 72 is less than a height "H" of the chamber 71 in the
vertical direction.
[0034] Operations of the agitator 7 shown in FIG. 2 are described
below with reference to FIGS. 3A-3D. When the heat transfer fluid
flows into the chamber 71 through the inlet 72, a jet of the heat
transfer fluid issuing from the inlet 72 into the chamber 71 occurs
due to a difference between the height "a" of the inlet 72 and the
height "H" of the chamber 71. As indicated by a solid line in FIG.
3A, the jet of the heat transfer fluid issuing into the chamber 71
is deflected toward a lower inner surface of the chamber member due
to the Coanda effect so that the jet can approach the lower inner
surface of the chamber member as close as possible or be attached
to the lower inner surface of the chamber member. Then, as
indicated by a broken line in FIG. 3A, a clockwise vortex VA is
produced between the jet and the lower inner surface of the chamber
member, and a counter-clockwise vortex VB is produced between the
jet and an upper inner surface of the chamber 71. At this time,
pressure is less in the vortex VA than in the vortex VB. Therefore,
as indicated by an arrow in FIG. 2 and FIG. 3A, a stream of the
heat transfer fluid toward the vortex VA occurs near the inlet 72
of the chamber 71. That is, the stream of the heat transfer fluid
circles from near the inlet 72 toward the lower inner surface of
the chamber member.
[0035] Due to the circulating stream, as shown in FIGS. 3B and 3C,
the jet, indicated by the solid line, moves away from the lower
inner surface of the chamber member, the vortex VA disappears, and
the vortex VB moves toward the inlet 72. Then, as shown in FIG. 3D,
the jet, indicated by the solid line, is deflected toward an upper
inner surface of the chamber member due to the Coanda effect so
that the jet can approach the upper inner surface of the chamber
member as close as possible or be attached to the upper inner
surface of the chamber member. Thus, the vortexes VA, VB in FIG. 3D
are symmetrically positioned relative to the vortexes VA, VB in
FIG. 3A. Then, phenomena like those shown in FIGS. 3B and 3C occurs
so that the state in the chamber 71 can return to FIG. 3A from FIG.
3D. In this way, when the heat transfer fluid flows into the
chamber 71, the states shown in FIGS. 3A-3D are repeated. Such an
oscillation phenomenon of the jet of the heat transfer fluid in the
chamber 71 is caused by the ups and downs of the vortexes VA, VB
that are located on opposite sides of the jet.
[0036] As described above, according to the first embodiment, at
least one of the apparatus of the heat transfer circuit 1 for
circulating the heat transfer fluid with the solvent and the small
particles dispersed in the solvent includes the agitator 7 in a
lower position of the container in the vertical direction.
[0037] In such an approach, even when the small particles
precipitate out of the solvent due to the stop of the pump 6 and
are deposited in the lower position of the apparatus in the
vertical direction due to the gravity, the heat transfer fluid can
be agitated by the agitator 7 so that the small particles can be
dispersed in the solvent. Thus, the heat conductivity of the heat
transfer fluid is maintained so that a desired heat transfer
performance can be obtained.
[0038] Preferably, the agitator 7 can be provided in at least one
of the radiator 4, the reserver tank 5, and the pipes 42, 45, 52,
and 53. That is, the agitator 7 can be located in a position where
it is likely that the precipitate of the small particles will
occur. Thus, the heat transfer fluid can be effectively agitated by
the agitator 7 so that the small particles can be dispersed in the
solvent.
[0039] The agitator 7 is configured as an oscillator for producing
vortexes in a jet of the heat transfer fluid issuing into the
chamber 71 so as to swing the jet. Thus, the agitator 7 swings the
heat transfer fluid in the chamber 71 during the circulation of the
heat transfer fluid in the heat transfer circuit 1. Thus, the heat
transfer fluid in the chamber 71 is agitated so that the
precipitate of the small particles in the chamber 71 can be
prevented.
[0040] The agitator 7 includes the chamber member defining the
chamber 71 and the nozzle defining the inlet 72 for the heat
transfer fluid to the chamber 71. The height "a" of the inlet 72 is
less than the height "H" of the chamber 71 in the vertical
direction so that the agitator 7 can serve as the oscillator. Since
the container located in the lower position of the apparatus itself
serves as the agitator 7, there is no need to add a separate
agitator. Thus, manufacturing cost can be reduced.
Second Embodiment
[0041] An apparatus having an agitator 8 according to a second
embodiment of the present invention is described below with
reference to FIG. 4. According to the second embodiment, the
agitator 8 is provided in a radiator 4A.
[0042] The agitator 8 is located in a lower position of a container
of the apparatus in the vertical direction. As shown in FIG. 4, the
agitator 8 includes a chamber 81 defined by a chamber member 41A
and an inlet passage 82 defined by an inlet pipe 42A that is
connected to an inlet 82a to the chamber 81. It is noted that the
chamber member 41A is a lower tank of the radiator 4A. That is, the
lower tank of the radiator 4A and the agitator 8 are a single
piece. The chamber member 41A has a cylindrical inner surface
defining the inlet 82a. The inlet passage 82 extends in a direction
of the tangent to the cylindrical inner surface of the chamber
member 41A. When the heat transfer fluid enters the chamber 81
through the inlet passage 82 of the inlet pipe 42A, the heat
transfer fluid flows along the cylindrical inner surface of the
chamber member 41A. Thus, in the chamber 81, the heat transfer
fluid moves from the outside to the inside to form a circle. In
this way, a swirling flow of the heat transfer fluid is produced in
the chamber 81.
[0043] As described above, according to the second embodiment, the
agitator 8 includes the chamber 81 and the inlet passage 82. The
chamber member 41A defining the chamber 81 has the cylindrical
inner surface, and the inlet passage 82 extends in the direction of
the tangent to the cylindrical inner surface of the chamber member
41A. In such an approach, the heat transfer fluid flowing into the
chamber 81 through the inlet passage 82 forms a swirling flow in
the chamber 81. Thus, the heat transfer fluid in the chamber 81 is
agitated so that the precipitate of the small particles in the
chamber 81 can be prevented.
Third Embodiment
[0044] An apparatus having an agitator 9 according to a third
embodiment of the present invention is described below with
reference to FIG. 5. According to the third embodiment, the
agitator 9 is provided in at least one of a radiator 4B and a
reserver tank 5B.
[0045] The agitator 9 is configured as an ultrasonic vibrator and
ultrasonically vibrates the heat transfer fluid collected in
chambers 41a, 51a in a lower position of containers (i.e., the
lower tank 41, the bottom container 51) of the radiator 4B and the
reserver tank 5B. The agitator 9 includes an ultrasonic transducer
and a vibrating member joined to the ultrasonic transducer. The
ultrasonic transducer is an electronic device for converting
electric power supplied from a power source such as a battery into
mechanical ultrasonic vibrations. The mechanical ultrasonic
vibrations are transmitted to the vibrating member so that a tip of
the vibrating member can ultrasonically vibrate in its length
direction. The ultrasonic vibrations are transmitted to the heat
transfer fluid around the vibrating member so that the heat
transfer fluid in the chambers 41a, 51a can be agitated.
[0046] As described above, according to the third embodiment, the
agitator 9 is configured as an ultrasonic vibrator and
ultrasonically vibrates the heat transfer fluid collected in the
chambers 41a, 51a during the circulation of the heat transfer fluid
in the heat transfer circuit 1. Thus, the heat transfer fluid in
the chambers 41a, 51a is agitated so that the precipitate of the
small particles in the chambers 41a, 51a can be prevented.
Fourth Embodiment
[0047] An apparatus having an agitator 10 according to a fourth
embodiment of the present invention is described below with
reference to FIG. 6. According to the fourth embodiment, the
agitator 10 is provided in a radiator 4C.
[0048] The agitator 10 is located in a lower position of a
container of the apparatus in the vertical direction. As shown in
FIG. 6, the agitator 10 is located in a chamber 41a of the lower
tank 41 of the radiator 4C. The agitator 10 includes a rotator 101,
a driven portion 102, and a rotating shaft 103. The rotator 101
rotates when the driven portion 102 or the rotating shaft 103 are
driven. The rotator 101 is coupled to the driven portion 102
through the rotating shaft 103. The rotator 101 is positioned below
the driven portion 102 in the vertical direction.
[0049] As shown in FIG. 6, the driven portion 102 is located at
almost the same height as the inlet pipe 42 that is connected to an
upper portion of the lower tank 41. The rotator 101 is located in a
lower position in the lower tank 41. For example, the driven
portion 102 can be an impeller or radially-arranged blades. The
driven portion 102 is driven by the heat transfer fluid flowing
into the chamber 41a so that the rotating shaft 103 can rotate. The
rotator 101 rotates with the rotating shaft 103 so that the heat
transfer fluid in the lower position in the chamber 41a can be
agitated.
[0050] As described above, according to the fourth embodiment, the
agitator 9 includes the rotator 101 in the chamber 41a. Thus, the
heat transfer fluid in the chamber 41a is agitated so that the
precipitate of the small particles in the chamber 41a can be
prevented.
[0051] The rotator 101 rotates with the driven portion 102 that is
driven by pressure of the heat transfer fluid flowing into the
chamber 41a. In such an approach, the rotator 101 rotates without
an external power source so that the heat transfer fluid in the
chamber 41a can be efficiently agitated.
[0052] Alternatively, the driven portion 102 can be driven by using
an external power source. For example, the driven portion 102 can
be driven by power supply from a starter of an engine or a motor of
the vehicle. The driven portion 102 can be driven by power
generated when a door of the vehicle is opened and closed.
Alternatively, a mechanical rotating power can be applied directly
to the rotator 101 or the rotating shaft 103.
Fifth Embodiment
[0053] An apparatus having an agitator 11 according to a fifth
embodiment of the present invention is described below with
reference to FIGS. 7 and 8. According to the fifth embodiment, the
agitator 11 is provided in at least one of a radiator 4D and a
reserver tank 5D.
[0054] The agitator 11 includes a cylindrical column 111 located in
a chamber 112 in a lower position of containers (i.e., the lower
tank 41, the bottom container 51) of the radiator 4D and the
reserver tank 5D. The cylindrical column 111 is positioned so that
the heat transfer fluid flowing into the chamber 112 can hit the
cylindrical column 111. For example, the cylindrical column 111 can
be positioned near the inlet to the chamber 112. As shown in FIG.
8, when the heat transfer fluid hits the cylindrical column 111, a
Karman vortex is created on the downstream side of the cylindrical
column 111.
[0055] In an example shown in FIGS. 7 and 8, an axis of the
cylindrical column 111 is in a horizontal direction perpendicular
to the vertical direction. The axis of the cylindrical column 111
is not limited to the horizontal direction. For example, the axis
of the cylindrical column 111 can be in the vertical direction.
[0056] In the example shown in FIGS. 7 and 8, one cylindrical
column 111 is provided in the chamber 112. Alternatively, two or
more cylindrical columns 112 can be provided in the chamber
112.
[0057] As described above, according to the fifth embodiment, the
agitator 11 includes the cylindrical column 111 in the chamber 112.
Thus, the heat transfer fluid in the chamber 112 is agitated so
that the precipitate of the small particles in the chamber 112 can
be prevented.
Sixth Embodiment
[0058] An apparatus having an agitator 12 according to a sixth
embodiment of the present invention is described below with
reference to FIGS. 10A-10C. According to the sixth embodiment, the
agitator 12 is provided in the radiator 4E.
[0059] The agitator 12 is located in the chamber 41a of the lower
tank 41, which is located in a lower position of the radiator 4E in
the vertical direction. The agitator 12 includes a thin film 122
having a fixed end 121 on one side and a free end on the other
side. The fixed end 121 is located at a predetermined height from a
bottom of the lower tank 41. When the heat transfer fluid flows
into the chamber 41a, the film 122 floats in the heat transfer
fluid depending on its specific gravity and elasticity.
[0060] As shown in FIG. 10A, in normal operation conditions where
the heat transfer fluid continuously flows into the chamber 41a,
the film 122 is stretched along a direction of flow of the heat
transfer fluid. Then, when the heat transfer fluid stops
circulating in the heat transfer circuit 1 due to, for example,
deactivation of the pump 6, the small particles start to
precipitate out of the solvent. As a result, as shown in FIG. 10B,
a precipitate D of the small particles on the film 122 occurs, and
the film 122 is deformed due to the weight of the precipitate D so
that the free end of the film 122 can hang down on the bottom of
the chamber 41 due to its elasticity. Then, when the pump 6 is
reactivated, the heat transfer fluid restarts to circulate in the
heat transfer circuit 1 and thus flows into the chamber 41a. As a
result, as shown in FIG. 10C, the film 122 is blown up by pressure
of the heat transfer fluid so that the precipitate D on the film
122 can be dispersed in the solvent of the heat transfer fluid.
[0061] As described above, according to the sixth embodiment, the
agitator 12 includes the film 122 located in the chamber 41a. When
the small particles precipitate out of the solvent due to the stop
of the circulation of the heat transfer fluid in the heat transfer
circuit 1, the precipitate D of the small particles occurs on the
film 122. Therefore, when the circulation of the heat transfer
fluid is restarted, the film 122 is blown up by the heat transfer
fluid flowing into the chamber 41a so that the precipitate D on the
film 122 can be dispersed. Thus, the heat transfer fluid in the
chamber 41a is agitated so that the precipitate of the small
particles in the chamber 41a can be prevented. The ability of the
agitator 12 to disperse the precipitate can be adjusted by
adjusting the size, the hardness, the elasticity, and/or the
like.
[0062] It is preferable that the film 122 be made of a shape-memory
material. For example, the film 122 can return to its original
shape according to temperature. When the film 122 returns to its
original shape, the precipitate on the film 122 is flipped up. In
this way, the film 122 can disperse the precipitate thereon by
itself. Thus, the ability of the agitator 12 to disperse the
precipitate can be improved.
Seventh Embodiment
[0063] An apparatus having an agitator 13 according to a seventh
embodiment of the present invention is described below with
reference to FIG. 11. According to the seventh embodiment, the
agitator 13 is provided in a radiator 4F.
[0064] As shown in FIG. 11, the agitator 13 includes a chamber 131
defined by the lower tank 41 located in the lower position of the
radiator 4F and an inlet passage 132 connected to the chamber 131.
The inlet passage 132 extends obliquely downward toward the chamber
131 in the vertical direction so that the heat transfer fluid
flowing into the chamber 131 through the inlet passage 132 can move
toward the bottom of the chamber 131. Thus, the heat transfer fluid
near the bottom of the chamber 131 is agitated so that the
precipitate D on the bottom of the chamber 131 can be
dispersed.
[0065] As described above, according to the seventh embodiment, the
agitator 13 includes the chamber 131 and the inlet passage 132
connected to the chamber 131 in such a manner the inlet passage
extends obliquely downward toward the chamber 131. In such an
approach, the heat transfer fluid flowing into the chamber 131
through the inlet passage 132 moves toward the bottom of the
chamber 131. Thus, the heat transfer fluid near the bottom of the
chamber 131 is agitated so that the precipitate Don the bottom of
the chamber 131 can be prevented. Since the precipitate D is likely
to occur on the bottom of the chamber 131, the agitator 13 can
effectively disperse the precipitate D.
Eighth Embodiment
[0066] An apparatus having an agitator 14 according to an eighth
embodiment of the present invention is described below with
reference to FIG. 12. According to the eighth embodiment, the
agitator 14 is provided in a radiator 4G.
[0067] As shown in FIG. 12, the agitator 14 includes a chamber 141
defined by a lower tank 41G located in the lower position of the
radiator 4G and an inlet passage 142 connected to the bottom of the
chamber 141 in such a manner that the heat transfer fluid flows
upward in the chamber 141 like a fountain flow. Thus, the heat
transfer fluid near the bottom of the chamber 141 is agitated so
that the precipitate D on the bottom of the chamber 141 can be
dispersed.
[0068] As described above, according to the eighth embodiment, the
agitator 14 includes the chamber 141 and the inlet passage 142
connected to the bottom of the chamber 141. In such an approach,
the heat transfer fluid near the bottom of the chamber 131 is
agitated so that the precipitate D on the bottom of the chamber 141
can be prevented. Since the precipitate D is likely to occur on the
bottom of the chamber 141, the agitator 14 can effectively disperse
the precipitate D.
Modifications
[0069] The embodiments described above can be modified in various
ways, for example, as follows.
[0070] The solvent of the heat transfer fluid can be an organic
solvent such as hexane, diethyl ether, chloroform, ethyl acetate,
tetrahydrofuran, dichloromethane, acetone, acetonitrile,
N,N-dimethylformamide, dimethyl sulfoxide, butanol acetate,
2-propanol, 1-propanol, methanol, ethanol, or formic acid.
[0071] The solvent can be a mixture of two components. In this
case, it is preferable that one component have a freezing-point
depression effect. For example, the solvent can be formed by adding
a freezing-point depressant to water. For example, the
freezing-point depressant can be potassium acetate or sodium
acetate. In such an approach, a freezing-point of the heat transfer
fluid is reduced so that the heat transfer fluid can be used even
in cold climates. Further, addition agents such as a rust inhibitor
and an antioxidant can be added to the solvent as needed.
[0072] In the first embodiment, the chamber 71 has a cubic shape.
The chamber 71 is not limited to the cubic shape. For example, the
chamber 71 can have a cylindrical shape or an oval shape. Although
the inlet 72 of the chamber 71 has a rectangular cross-section, the
inlet 72 is not limited to the rectangular cross-section. For
example, the inlet 72 can have a circular cross-section, an
ellipsoidal cross-section, or a semicircular cross-section.
[0073] The embodiments described above can be combined in various
ways as needed.
[0074] Such changes and modifications are to be understood as being
within the scope of the present invention as defined by the
appended claims.
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