U.S. patent application number 11/894529 was filed with the patent office on 2008-06-26 for cooling apparatus for on-vehicle electronic device.
This patent application is currently assigned to DENSO Corporation. Invention is credited to Takahisa Fujii, Yuji Ito, Yasuhiko Niimi.
Application Number | 20080148755 11/894529 |
Document ID | / |
Family ID | 39078982 |
Filed Date | 2008-06-26 |
United States Patent
Application |
20080148755 |
Kind Code |
A1 |
Fujii; Takahisa ; et
al. |
June 26, 2008 |
Cooling apparatus for on-vehicle electronic device
Abstract
A cooling apparatus for cooling an electronic device 100 mounted
on a vehicle in combination with an automotive climate control
system 10 having a refrigeration cycle for compressing and
expanding a first heating medium is disclosed. The cooling
apparatus includes a second heating medium in liquid form, a
tubular path 60 for circulating the second heating medium flowing
therein, a heat absorber 30 for transmitting the heat from the
electronic device 100 to the second heating medium, a heat
dissipator 40 for transmitting the heat from the second heating
medium to the evaporator 15, and a pump 50 for circulating the
second heating medium. The heat dissipator 40 is coupled to the
tank unit 15c of the evaporator 15.
Inventors: |
Fujii; Takahisa;
(Kariya-city, JP) ; Ito; Yuji; (Okazaki-city,
JP) ; Niimi; Yasuhiko; (Handa-city, JP) |
Correspondence
Address: |
HARNESS, DICKEY & PIERCE, P.L.C.
P.O. BOX 828
BLOOMFIELD HILLS
MI
48303
US
|
Assignee: |
DENSO Corporation
Kariya-city
JP
|
Family ID: |
39078982 |
Appl. No.: |
11/894529 |
Filed: |
August 21, 2007 |
Current U.S.
Class: |
62/259.2 ;
62/331 |
Current CPC
Class: |
B60H 2001/00949
20130101; B60H 2001/00928 20130101; F28F 9/0234 20130101; B60H
2001/00307 20130101; B60H 1/00878 20130101; B60H 2001/00614
20130101 |
Class at
Publication: |
62/259.2 ;
62/331 |
International
Class: |
F25D 23/12 20060101
F25D023/12 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 23, 2006 |
JP |
2006-227105 |
Claims
1. A cooling apparatus for cooling an object to be cooled mounted
on a vehicle in combination with an automotive climate control
system having a refrigeration cycle for compressing and expanding a
first heating medium, wherein the climate control system includes
an evaporator having a plurality of juxtaposed tubes with a first
heating medium flowing therein and a tank unit connected with the
ends of the plurality of the tubes for distributing and collecting
the first heating medium in the plurality of the tubes, the
evaporator exchanges heat between air blown by the blower of the
climate control system and the first heating medium; the cooling
apparatus comprising a second heating medium in liquid form, a
tubular path for circulating the second heating medium flowing
therein, a heat absorber for transmitting the heat from the object
to the second heating medium, a heat dissipator for transmitting
the heat from the second heating medium to the evaporator, and a
pump for circulating the second heating medium, the heat dissipator
being coupled to the tank unit of the evaporator.
2. The cooling apparatus according to claim 1, wherein the second
heating medium in liquid form is brine having a solidification
point of lower than 0.degree. C.
3. The cooling apparatus according to claim 1, wherein the heat
dissipator is a unit independent of the evaporator and mounted on
and coupled to the tank unit of the evaporator.
4. The cooling apparatus according to claim 1, comprising a
plurality of heat dissipators, wherein the evaporator includes a
plurality of tank units connected to the each end of the tubes, and
the plurality of the heat dissipators are coupled to the plurality
of the tank units.
5. The cooling apparatus according to claim 1, further comprising a
temperature sensor for detecting the temperature of the second
heating medium and a control unit for activating the blower of the
climate control system when the temperature detected by the
temperature sensor reaches a predetermined temperature.
6. The cooling apparatus according to claim 5, wherein the climate
control system includes an air blowing unit case for accommodating
the evaporator and the blower and having a heat discharge outlet
adapted to be opened or closed, and the control unit controls the
heat discharge outlet to open upon activation of the blower.
7. The cooling apparatus according to claim 5, wherein the control
unit controls the pump to reduce the flow rate of the second
heating medium in liquid form when the temperature detected by the
temperature sensor drops to or below a predetermined
temperature.
8. The cooling apparatus according to claim 7, further comprising a
flow rate control valve, wherein the control unit controls the flow
rate control valve in place of the pump.
9. The cooling apparatus according to claim 5, further comprising a
second temperature sensor for detecting the temperature of the heat
absorber, wherein the tubular path for circulating the second
heating medium in liquid form includes a tubular bypass for
circumventing the heat absorber and a switching valve arranged at a
diverging point of the tubular bypass, and wherein the control unit
activates the switching valve in such a manner that the second
heating medium in liquid form circumvents the heat absorber and
flows through the tubular bypass when the temperature detected by
the temperature sensor drops to or below a predetermined
temperature, and the second heating medium flows through the heat
absorber when the temperature detected by the second temperature
sensor rises to or above another predetermined temperature.
10. The cooling apparatus according to claim 1, further comprising
a temperature sensor for detecting the temperature of the second
heating medium and a control unit for activating the blower of the
climate control system when the temperature detected by the
temperature sensor reaches a predetermined temperature, wherein the
climate control system includes an air blowing unit case for
accommodating the evaporator and the blower and having a heat
discharge outlet adapted to open/close, wherein the air blowing
unit case includes an external air inlet, an internal air inlet and
an internal/external air switching door for opening/closing the
external air inlet and the internal air inlet, wherein in the case
where the temperature detected by the temperature sensor while the
vehicle is moving at a predetermined speed or higher reaches a
predetermined temperature, the control unit controls the operation
of the internal/external air switching door to introduce air from
the external air inlet while at the same time opening the heat
discharge outlet.
11. The cooling apparatus according to claim 1, wherein the object
to be cooled is an electronic device mounted on vehicle.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to a cooling apparatus for cooling an
object to be cooled such as an electronic device mounted on a
vehicle in combination with an automotive climate control system,
or in particular to a cooling apparatus using brine as a heat
transfer medium.
[0003] 2. Description of the Related Art
[0004] The evaporator of an automotive climate control system
exchanges heat between refrigerant flowing in the evaporator and
air in the passenger compartment. A cooling apparatus for cooling
an on-vehicle object using this evaporator is known as disclosed in
Japanese Unexamined Patent Publication No. 2001-1753. Japanese
Unexamined Patent Publication No. 2001-1753 describes an air
conditioning system having a cooling storage cycle for cooling a
cool storage medium to supply cool air even when the vehicle engine
is stopped. This cooling storage cycle uses brine as a heat
transfer medium, and evaporator tubes are integrated as a double
tube, in which the refrigerant flows in the inner tube while brine
flows in the outer tube, so that the brine is cooled thereby
cooling the cooling storage medium making up the object to be
cooled.
SUMMARY OF THE INVENTION
[0005] The brine in the cooling storage cycle described above cools
the cooling storage medium satisfactorily. The brine flowing in the
outer tube of the double tube, however, constitutes a thermal
resistance against heat exchange between the refrigerant and air in
the passenger compartment, with the result that the quick-acting
characteristic of the cooling operation of the climate control
system may be deteriorated. Also, the process of integrally forming
a double tube is complicated, and an evaporator having such a
double tube is specially structured and expensive.
[0006] This invention has been achieved to solve the aforementioned
problem of the prior art and the object thereof is to provide a
cooling apparatus for cooling the object to be cooled such as an
on-vehicle electronic device in combination with an automotive
climate control system without deteriorating the quick-acting
cooling characteristic of the automotive climate control
system.
[0007] In order to achieve the object described above, the present
invention employs the technical means described below.
[0008] According to this invention, there is provided a cooling
apparatus for cooling an object to be cooled (100) mounted on the
vehicle in combination with an automotive climate control system
(10) having a refrigeration cycle for compressing and expanding a
first heating medium, [0009] wherein the climate control system
(10) includes an evaporator (15) having a plurality of juxtaposed
tubes with the first heating medium flowing therein and a tank unit
(15c) connected to the ends of the plurality of tubes for
distributing and collecting the first heating medium to and from
the plurality of tubes, and in which an evaporator exchanges heat
between air blown by a blower (16) of the climate control system
(10) and the first heating medium, the cooling apparatus including
a second heating medium in liquid form, a tubular path (60) for
circulating the second heating medium flowing therein, a heat
absorber (30) for transmitting the heat from the object (100) to
the second heating medium, a heat dissipator (40) for transmitting
the heat from the second heating medium to the evaporator (15), and
a pump (50) for circulating the second heating medium, the heat
dissipator (40) being coupled to the tank unit (15c) of the
evaporator (15).
[0010] The heat dissipator of the cooling apparatus, which is
coupled to the tank unit of the evaporator of the climate control
system, has no adverse effect on heat exchange between the first
heating medium (refrigerant) flowing inside the tubes and air
blowing between the tubes and fins of the evaporator, and
therefore, the quick-acting cooling characteristic of the climate
control system is not deteriorated. Also, even in the case where
the climate control system is not being operated with no
refrigerant flowing in the evaporator, heat can be normally
radiated using an evaporator formed of aluminum as a heat radiator
having a large surface area.
[0011] According to this invention, the second heating medium in
liquid form is brine having a solidification point of lower than
0.degree. C., and therefore, can be prevented from being frozen
even in a cold environment.
[0012] According to this invention, the heat dissipator (40) is
configured independently of the evaporator (15) and coupled to by
being mounted on the tank unit (15c) of the evaporator. With this
configuration, the evaporator used for the cooling apparatus
according to the invention can be realized with a minor design
change or without any design change of the existing evaporator.
[0013] According to this invention, the cooling apparatus may
comprise a plurality of heat dissipators (40), the evaporator (15)
may include a plurality of tank units (15b, 15c) connected to the
each end of the tubes, and the plurality of the heat dissipators
(40) are coupled to the plurality of the tank units (15b, 15c). As
a result, a more uniform temperature distribution of the core unit
of the evaporator is obtained and the cooling capacity of the
cooling apparatus is improved.
[0014] According to this invention, the cooling apparatus may
further comprise a temperature sensor (70) for detecting the
temperature (Tb) of the second heating medium, and a control unit
(80) for activating the blower (16) of the climate control system
(10) when the temperature (Tb) detected by the temperature sensor
(70) reaches a predetermined temperature (T1).
[0015] With this configuration, even in the case where the climate
control system is not being operated and no refrigerant is flowing
in the evaporator, heat transmitted to the evaporator from the heat
dissipators of the cooling apparatus can be efficiently radiated by
applying the air of the blower to the evaporator.
[0016] According to this invention, the climate control system (10)
includes an air blowing unit case (17) having a heat discharge
outlet port (25) for accommodating the evaporator (15) and the
blower (16) and adapted to be opened or closed, and the control
unit (80) controls the heat discharge outlet port (25) to open upon
activation of the blower (16). As a result, even in the case where
the climate control system is not being operated and the cool air
outlet of the air blowing unit case is closed, the blower can be
activated of the cooling apparatus.
[0017] According to this invention, the control unit (80) controls
the pump (50) to reduce the flow rate of the second heating medium
in liquid form when the temperature (Tb) detected by the
temperature sensor (70) drops to or below a predetermined
temperature (T3). As a result, condensation or the like, which
otherwise might be caused by excessively cooling the electronic
device can be prevented.
[0018] According to this invention, the cooling apparatus further
comprises a flow rate control valve, and the control unit (80)
controls the flow rate control valve in place of the pump (50). As
a result, condensation or the like, which otherwise might be caused
by excessively cooling the electronic device can be prevented.
[0019] According to this invention, the cooling apparatus may
further comprise a second temperature sensor (72) for detecting the
temperature (Tk) of the heat absorber (30), wherein the tubular
path (60) for circulating the second heating medium in liquid form
includes a tubular bypass (61) for circumventing the heat absorber
(30) and a switching valve (62) arranged at a diverging point of
the tubular bypass (61), and wherein the control unit (80)
activates the switching valve (62) in such a manner that the second
heating medium in liquid form circumvents the heat absorber (30)
and flows through the tubular bypass (61) when the temperature (Tb)
detected by the temperature sensor (70) drops to or below a
predetermined temperature (T3) and the second heating medium flows
through the heat absorber (30) when the temperature (Tk) detected
by the second temperature sensor (72) rises to or above another
predetermined temperature (T5). As a result, condensation or the
like, which otherwise might be caused by excessive cooling of the
electronic device can be also prevented.
[0020] According to this invention, the cooling apparatus may
further comprise a temperature sensor (70) for detecting the
temperature (Tb) of the second heating medium and a control unit
(80) for activating the blower (16) of the climate control system
(10) when the temperature (Tb) detected by the temperature sensor
(70) reaches a predetermined temperature (T1), wherein the climate
control system (10) includes an air blowing unit case (17) for
accommodating the evaporator (15) and the blower (16) and having a
heat discharge outlet (25) adapted to open/close, wherein the air
blowing unit case (17) includes an external air inlet (19), an
internal air inlet (18) and an internal/external air switching door
(20) for opening/closing the external air inlet (19) and the
internal air inlet (18), wherein in the case where the temperature
(Tb) detected by the temperature sensor (70) while the vehicle is
running at a predetermined speed or higher reaches a predetermined
temperature (T1), the control unit (80) controls the operation of
the internal/external air switching door (20) to introduce air from
the external air inlet (19) while at the same time opening the heat
discharge outlet port (25). As a result, the heat from the heat
dissipator of the cooling apparatus can be radiated by cooling the
evaporator with air flow caused by driving the vehicle without
activating the blower.
[0021] Incidentally, the reference numeral in each parenthesis
attached to each name of the means described above shows an example
of correspondence with the specific means described in the
embodiments below.
[0022] The present invention may be more fully understood from the
description of preferred embodiments of the invention, as set forth
below, together with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is a schematic diagram showing the cooling apparatus
according to a first embodiment of the invention, and the cooling
circuit of the climate control system collaborating with the
cooling apparatus.
[0024] FIG. 2 is a schematic diagram showing the state in which the
heat dissipator of the cooling apparatus is coupled to the
evaporator of the climate control system.
[0025] FIG. 3 is a schematic diagram showing the state in which the
heat dissipator of the cooling apparatus according to a second
embodiment of the invention is coupled to the evaporator of the
climate control system.
[0026] FIG. 4 is a schematic diagram showing the cooling circuit of
the cooling apparatus according to a third embodiment and the air
blowing unit case and the blower of the climate control system.
[0027] FIG. 5 is a schematic diagram showing the cooling circuit of
the cooling apparatus according to a fourth embodiment and the air
blowing unit case and the blower of the climate control system.
[0028] FIG. 6 is a control flowchart for the cooling apparatus
according to the fourth embodiment.
[0029] FIG. 7 is a schematic diagram showing the cooling circuit of
the cooling apparatus according to a fifth embodiment of the
invention.
[0030] FIG. 8 is a control flowchart for the cooling apparatus
according to the fifth embodiment.
[0031] FIG. 9 is a schematic diagram showing the cooling circuit of
the cooling apparatus according to a sixth embodiment and the air
blowing unit case and the blower of the climate control system.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0032] With reference to the accompanying drawings, a preferred
first embodiment of the invention will be explained in detail. The
cooling apparatus 1 according to the first embodiment is for
cooling an electronic device mounted on a vehicle and configured to
radiate heat generated in the electronic device to the evaporator
of an automotive climate control system. FIG. 1 is a schematic
diagram showing the cooling apparatus 1 according to the first
embodiment and the climate control system 10 collaborating with the
cooling apparatus 1. With reference to FIG. 1, the climate control
system 10 includes, interconnected by tubes, a compressor 11 for
compressing a first heating medium (hereinafter referred to as the
refrigerant), a condenser 12 for condensing and liquefying by
cooling the refrigerant compressed into a high temperature by heat
exchange with the atmospheric air, a liquid tank 13 for separating
the refrigerant into a liquid and gas, an expansion valve 14 for
expanding the refrigerant, and an evaporator 15 for exchanging heat
between the low temperature refrigerant and the air in the
passenger compartment. The refrigerant flows in the tubular paths
in the direction of the white arrows. The evaporator 15 is
accommodated in an air blowing unit case 17 together with a blower
16 for blowing air to the evaporator 15. An internal air inlet 18,
an external air inlet 19 and an internal/external air switching
door 20 for opening/closing these inlets are arranged upstream of
the blower 16 of the air blowing unit case 17. A heater core 21 for
the heating operation, an air outlet 22 directed toward the upper
half bodies of the vehicle occupants, an air outlet 23 directed to
the feet of the occupants, a defroster air outlet 24, a heat
discharge air outlet 25, doors 26, 27, 28 for opening/closing these
air outlets and an auto/manual switching door 29 are arranged
downstream of the evaporator 15.
[0033] The evaporator 15 according to this embodiment is of an
ordinary type called a "drone cup" used for the automotive climate
control system, and therefore, only a general structure thereof is
shown in FIG. 2. As shown in FIG. 2, the evaporator 15 includes a
core unit 15a formed of a multiplicity of fins and tubes arranged
in alternate layers in the vertical direction of the drawing, an
upper tank unit 15b and a lower tank unit 15c connected to the
upper and lower ends, respectively, of the plurality of the tubes
and extending in the horizontal direction in the drawing to
distribute the refrigerant to and collect the refrigerant from the
plurality of the tubes, and a refrigerant inlet port 15d and a
refrigerant outlet port 15e. Although the evaporator 15 according
to this embodiment has upper and lower tank units, the invention
may alternatively employ an evaporator having a tank unit on one
side, or on the lower side thereof.
[0034] In the cooling apparatus 1 according to the first
embodiment, as shown in FIG. 1, the on-vehicle electronic device
100 is cooled by circulating a second heating medium in liquid form
flowing in the directions of the black arrows between the
high-temperature on-vehicle electronic device 100 and the
low-temperature evaporator 15. According to this embodiment, the
second heating medium in liquid form is brine having a
solidification point of lower than 0.degree. C. The cooling
apparatus 1 is configured of, connected by a tubular path 60, a
heat absorber 30 for transmitting heat from the electronic device
100 to the brine, a heat dissipator 40 for transmitting heat from
the brine to the evaporator 15 and a pump 50 for circulating the
brine.
[0035] The heat dissipator, as designated by reference numeral 40
in FIG. 2, includes a heat dissipator case 41 formed of aluminum
substantially in the shape of a parallelepipedal box, and a brine
inlet port 42 and a brine outlet port 43 arranged on the opposed
side surfaces of the heat dissipator case 41. The brine is filled
and flows in the space formed in the case. The heat dissipator 40
has one large-area side of the parallelepiped thereof brazed or
caulked fixedly in close contact on the bottom surface of the lower
tank unit 15c of the evaporator. The use of the lower tank unit 15c
causes the refrigerant stored therein to exhibit a function
equivalent to a heat pipe, and therefore, improvement in cooling
capacity is expected.
[0036] The heat absorber 30, though not shown in detail, like the
aforementioned heat dissipator 40, includes a heat absorber case
formed of aluminum substantially in the shape of a parallelepipedal
box, and a brine inlet port and a brine outlet port arranged on the
opposed side surfaces of the case. The brine is filled and flows in
the space formed in the case. The heat absorber case has one side
surface thereof fixed in contact with the high-temperature parts of
the electronic device 100 with a band or the like to receive heat
therefrom. For this purpose, fixing means such as a screw may be
used in accordance with the structure of the electronic device 100
to be cooled, or depending on the cooling conditions, the heat
absorber unit case may be placed in a casing of the electronic
device, surrounded by high-temperature air but not in contact with
any heat-generating parts thereof.
[0037] The operation of the cooling apparatus 1 according to this
embodiment will now be explained. The heat generated in the
electronic device 100 is transmitted to the brine through the heat
absorber 30, and the brine is sent to the heat dissipator 40 by the
pump 50. The heat contained in the brine is transmitted to the
low-temperature refrigerant in the lower tank unit 15c of the
evaporator through one side of the heat dissipator case 41 and the
bottom of the lower tank unit 15c thereby to cool the electronic
device 100.
[0038] The heat transmission explained above concerns a case in
which the compressor 11 of the climate control system 10 is
activated and the low-temperature refrigerant flows in the
evaporator 15. Nevertheless, the cooling apparatus 1 according to
the invention can cool the electronic device 100 even when the
compressor 11 of the climate control system is not being operated.
Specifically, in a case where the compressor 11 is not in
operation, the temperature of the evaporator 15 is substantially
equal to ambient air temperature. However, since the electronic
device 100 generates heat, the temperature thereof is higher than
ambient air temperature, as well as the temperature of the brine
for transmitting the heat of the electronic device 100. Thus, heat
contained in the brine of the heat dissipator 40, after being
transmitted to the metal case forming the lower tank unit 15c of
the evaporator and the tubes and fins of the evaporator, is
dissipated into ambient air thereby to cool the electronic device
100. The core unit of the evaporator has a large surface area, and
therefore, the evaporator, even if no refrigerant flows therein,
can be used as a heat radiator. Also, heat transmitted from the
brine to the evaporator 15 is not only radiated from the evaporator
15 by the natural cooling function of air, but also can be radiated
efficiently by being forcibly cooled by air blown from the blower
16 to the evaporator 15. As another alternative, without activating
the blower 16, heat can be radiated forcibly by atmospheric air
introduced and blown to the evaporator 15 while the vehicle is
moving.
[0039] The heat dissipator of the cooling apparatus according to
the first embodiment described above is mounted on and coupled to
the lower tank unit of the evaporator. Alternatively, the heat
dissipator case and the lower tank unit of the evaporator may be
formed integrally with each other. In such a case, contact heat
resistance which otherwise might be generated between the
independent heat dissipator 40 and the lower tank unit according to
the first embodiment is eliminated, and therefore heat conductivity
is improved.
[0040] A cooling apparatus 2 according to a second embodiment will
not be explained with reference to FIG. 3. FIG. 3 is a schematic
diagram showing a state in which the heat dissipators 40 are
coupled to the evaporator 15. The cooling apparatus 2 according to
this embodiment includes two heat dissipators 40 mounted on the
lower tank unit 15c and the upper tank unit 15b, respectively. As a
result, a more uniform temperature distribution of the core unit
15a of the evaporator is obtained and cooling capacity improved.
Incidentally, since the brine is supplied to the two heat
dissipators 40 from a single heat absorber, a diverging point (not
shown) is formed midway of the tubular path 60.
[0041] A cooling apparatus 3 according to a third embodiment will
now be explained with reference to FIG. 4. In FIG. 4, the
compressor, the condenser and the like making up the refrigeration
cycle of the climate control system are not shown. The cooling
apparatus 3 according to the third embodiment includes a
temperature sensor 70 and a control unit 80 in addition to the
cooling apparatus according to the first embodiment. Further, the
cooling apparatus 3 includes three heat absorbers 30. The
temperature sensor 70 is arranged midway of the tubular path 60
leading from the heat dissipator 40 to the heat absorber 30 to
detect the brine temperature, and the control unit 80 can receive a
signal from the temperature sensor 70. Also, the three heat
absorbers 30 are mounted on three electronic devices 100,
respectively.
[0042] The control unit 80 activates the blower 16 in the air
blowing unit case 17 in accordance with temperature detected by the
temperature sensor 70 while the compressor is not being operated.
Specifically, in a case where the brine temperature Tb rises to a
predetermined temperature T1 or higher, the blower 16 is activated
to forcibly cool the evaporator 15 by air, however when the
detected temperature Tb drops to a predetermined temperature T2
lower than the predetermined temperature T1, the blower 16 is
stopped. Also, the control unit 80 activates an electric motor (not
shown) for opening the door 28 on the heat discharge outlet 25 at
the same time as the blower 16. In order to reduce the failure rate
of the blower motor 16a, the r.p.m. of the blower 16 may be
increased or decreased without starting/stopping the blower 16 as
described above. Also, the brine temperature may be measured at
other points than the aforementioned points. For example, the
temperature of the brine in the heat absorber 30 or the heat
dissipator 40 may be measured, or the temperature of the case of
the heat absorber or the heat dissipator may be measured as the
brine temperature. As another alternative, the temperature of the
electronic device 100 may be measured by a temperature sensor.
[0043] A cooling apparatus 4 according to a fourth embodiment will
now be explained with reference to FIG. 5. When the climate control
system is operating to cool the passenger compartment, i.e. when
both the compressor and the blower 16 are in operation, the cooling
power of the cooling apparatus 4 is maximised. An excessive cooling
operation, however, may reduce the surface temperature of the
electronic device 100 below ambient air temperature and may form
condensation on the electronic device 100. In view of this, with
the cooling apparatus 4 according to the fourth embodiment, the
control unit 80 further has the function of adjusting the output of
the pump 50 and thus regulate the flow rate of the circulating
brine. As a result, the electronic device 100 is prevented from
excessively decreasing in temperature and forming condensation. In
a case where the brine temperature Tb detected by the temperature
sensor 70 drops to a predetermined temperature T3 or lower, the
control unit 80 decreases the pump output and thus reduces the flow
rate of the circulating brine, however when the temperature Tb
rises to a predetermined temperature T4 or higher, the pump output
is increased for an increased flow rate. Incidentally, the
temperature T3 is determined by comparing the internal air
temperature Ta detected by the internal air temperature sensor 71
normally held in the climate control system with the brine
temperature Tb, and therefore, the temperature T3 changes according
to internal air temperature Ta.
[0044] A control flowchart of the cooling apparatus according to
the fourth embodiment is shown in FIG. 6. As shown in FIG. 6, the
control unit 80 controls the on/off operation of the blower for the
cooling apparatus and the on/off operation of the heat discharge
outlet when the compressor and the blower of the climate control
system are not being operated, and controls the flow rate of the
brine when the compressor and the blower of the climate control
system are both in operation.
[0045] Instead of controlling the flow rate of the circulating
brine by controlling the output of the pump 50 as in the cooling
apparatus 4 according to the fourth embodiment, a flow rate control
valve may be arranged in the brine circulating path, and the flow
rate may be controlled by the control unit 80 adjusting the valve
opening degree of the flow rate control valve.
[0046] A cooling apparatus 5 according to a fifth embodiment will
now be explained with reference to the schematic diagram of FIG. 7
and the flowchart of FIG. 8. In FIG. 7, neither the compressor and
the condenser making up the refrigeration cycle of the climate
control system nor the air blowing unit case and the blower are
shown. The cooling apparatus 5, like the cooling apparatus
according to the fourth embodiment, can control the on/off
operation of the blower and the flow rate of the brine to prevent
excessive cooling. In the cooling apparatus 5, the tubular bypass
61 circumventing the heat absorbers 30 is formed in the tubular
path 60 of the brine, and a three-way valve 62 is arranged at the
diverging point of the tubular bypass 61. Further, the cooling
apparatus 5 according to this embodiment, in addition to the first
temperature sensor 70 for detecting the brine temperature, includes
a second temperature sensor 72 for detecting the temperature Tk of
the case of one of the three heat absorbers 30 which is coupled to
the electronic device 100 having the lowest allowable temperature.
In a case where the brine temperature Tb drops to a predetermined
temperature T3 or lower, the control unit 80 switches the three-way
valve 62 so that the brine flows in the tubular bypass 61, however
when the temperature Tk of the case of the heat absorber 30
detected by the second temperature sensor 72 rises to another
predetermined temperature T5 or higher, on the other hand, the
three-way valve 62 is switched so that the brine flows in the heat
absorbers 30.
[0047] A cooling apparatus 6 according to a sixth embodiment will
now be explained with reference to FIG. 9. The cooling apparatus 6
according to this embodiment, like the cooling apparatus according
to the third embodiment, includes a brine tubular path 60, heat
absorbers 30, a heat dissipator 40, a pump 50, a temperature sensor
70 and a control unit, but differs from the cooling apparatus
according to the third embodiment in that in this embodiment, the
evaporator 15 is cooled using the air flow caused by a running
vehicle. Assuming that the vehicle is moving at a higher than
predetermined speed with the compressor and the blower 16 not in
operation. The cooling apparatus according to the sixth embodiment
operates so that in the case where the brine temperature Tb rises
to a predetermined temperature T1 or higher, the internal/external
air switching door 20 of the air blowing unit case 17 is switched
to introduce atmospheric air in accordance with a command from the
control unit 80. Also, the control unit 80 activates an electric
motor (not shown) to open the door 28 of the heat discharge outlet
25 when the internal/external switching door 20 is switched to
introduce atmospheric air. As a result, the evaporator 15 and the
brine are forcibly cooled by air flow caused by a moving
vehicle.
[0048] While the invention has been described by reference to
specific embodiments chosen for purposes of illustration, it should
be apparent that numerous modifications could be made thereto by
those skilled in the art without departing from the basic concept
and scope of the invention.
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