U.S. patent application number 13/220641 was filed with the patent office on 2012-11-22 for heat disspation device and control method.
This patent application is currently assigned to FOXCONN TECHNOLOGY CO., LTD.. Invention is credited to NIEN-TIEN CHENG, HUNG-NIEN CHIU, CHING-BAI HWANG.
Application Number | 20120292007 13/220641 |
Document ID | / |
Family ID | 47174064 |
Filed Date | 2012-11-22 |
United States Patent
Application |
20120292007 |
Kind Code |
A1 |
CHIU; HUNG-NIEN ; et
al. |
November 22, 2012 |
HEAT DISSPATION DEVICE AND CONTROL METHOD
Abstract
A heat dissipation device for cooling a heat generating
component, includes a fins module, a heat pipe, a fan, at least two
temperature sensors, and a control system. The heat pipe includes
an evaporation section absorbing heat from the heat generating
component, and a condensation section thermally connected to the
fins module. The fan is for driving airflow towards the fins
module. The at least two temperature sensors are arranged on the
evaporation section of the heat pipe, for continuously sensing
temperatures of their respective positions on the heat pipe. The
control system adjusts the speed of the fan and/or the operating
power of the heat generating component according to the sensed
temperatures of the at least two temperature sensors. A method for
controlling the heat dissipation device is also provided.
Inventors: |
CHIU; HUNG-NIEN; (Tu-Cheng,
TW) ; HWANG; CHING-BAI; (Tu-Cheng, TW) ;
CHENG; NIEN-TIEN; (Tu-Cheng, TW) |
Assignee: |
FOXCONN TECHNOLOGY CO.,
LTD.
Tu-Cheng
TW
|
Family ID: |
47174064 |
Appl. No.: |
13/220641 |
Filed: |
August 29, 2011 |
Current U.S.
Class: |
165/247 ;
165/104.26 |
Current CPC
Class: |
F28D 15/0233 20130101;
F28D 2021/0028 20130101; F28D 15/0275 20130101; F28D 15/06
20130101; F28F 1/32 20130101 |
Class at
Publication: |
165/247 ;
165/104.26 |
International
Class: |
F28F 13/00 20060101
F28F013/00; F28D 15/04 20060101 F28D015/04 |
Foreign Application Data
Date |
Code |
Application Number |
May 20, 2011 |
TW |
100117701 |
Claims
1. A heat dissipation device for cooling a heat generating
component, comprising: a fins module; a heat pipe comprising an
evaporation section for absorbing heat of the heat generating
component, and a condensation section thermally connected to the
fins module; a fan for driving airflows to flow towards the fins
module; at least two temperature sensors arranged on the
evaporation section of the heat pipe, the at least two temperature
sensors being for continuously sensing temperatures of their
respective positions on the heat pipe to get sensed temperatures;
and a controlling system for adjusting a speed of the fan and/or an
operating power of the heat generating component according to the
sensed temperatures of the at least two temperature sensors.
2. The heat dissipation device of claim 1, wherein the controlling
system compares the sensed temperatures with a first predetermined
temperature, and adjust the speed of the fan and/or an operating
power of the heat generating component according to the
comparison.
3. The heat dissipation device of claim 2, wherein the controlling
system increases the speed of the fan in condition that anyone the
sensed temperatures is higher than the first predetermined
temperature.
4. The heat dissipation device of claim 3, wherein the controlling
system compares a difference between the sensed temperatures from
the at least two temperature sensors with a first predetermined
temperature difference, and decreases the speed of the fan in
condition that the difference between the sensed temperatures is
larger than the first predetermined temperature difference.
5. The heat dissipation device of claim 4, wherein the controlling
system compares the sensed temperatures with a second predetermined
temperature, and decreases the operating power of the heat
generating component in condition that anyone of the sensed
temperatures is higher than the second predetermined
temperature.
6. A method for cooling a heat generating component, comprising:
providing a heat dissipation device with a heat pipe and a fan, and
attaching an evaporation section of the heat pipe to the heat
generating component; getting sensed temperatures of different
positions on the evaporation section of the heat pipe; adjusting a
speed of the fan and/or an operating power of the heat generating
component according to the sensed temperatures.
7. The method of claim 6, wherein the sensed temperatures are
compared with a first predetermined temperature, and the speed of
the fan and/or an operating power of the heat generating component
is/are adjusted according to the comparison.
8. The method of claim 7, wherein the speed of the fan is increased
in condition that anyone the sensed temperatures are higher than
the first predetermined temperature.
9. The method of claim 8, wherein a difference between the sensed
temperatures from the at least two temperature sensors is compared
with a first predetermined temperature difference, and the speed of
the fan is decreased in condition that the difference between the
sensed temperatures is larger than the first predetermined
temperature difference.
10. The method of claim 9, wherein the sensed temperatures are
compared with a second predetermined temperature, and the operating
power of the heat generating component is decreased in condition
that anyone of the sensed temperatures is higher than the second
predetermined temperature.
Description
BACKGROUND
[0001] 1. Technical Field
[0002] The present disclosure generally relates to heat dissipation
devices, and control method for the heat dissipation devices.
[0003] 2. Description of Related Art
[0004] During operation of electronic devices such as computer
central processing units (CPUs), a large amount of heat is often
produced. The heat must be quickly removed from the electronic
devices to prevent them from becoming unstable or being damaged.
Many heat dissipation devices are employed to dissipate heat
produced by the electric device. A heat dissipation device
generally comprises a base attached to the electric device, a
plurality of fins thermally connected to the base by heat pipes,
and a fan for driving airflow towards the fins. The base is
intimately attached to the CPU for absorbing the heat generated by
the CPU. Most of the heat accumulated on the base is transferred to
the fins by the heat pipes and then the fins are cooled by airflow
driven by the fan.
[0005] To achieve high efficiency heat transfer, a fan speed of the
heat dissipation device is high, which is not energy saving.
[0006] Therefore, what is needed is to provide a heat dissipation
device capable of effectively improving heat dissipating efficiency
under different temperatures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Many aspects of the disclosure can be better understood with
reference to the following drawings. The components in the drawings
are not necessarily drawn to scale, the emphasis instead being
placed upon clearly illustrating the principles of the
disclosure.
[0008] FIG. 1 is a schematic view of a heat dissipation device in
accordance with an embodiment of the present disclosure.
[0009] FIG. 2 is similar to FIG. 1, but showing another aspect of
the heat dissipation device.
[0010] FIG. 3 is an exploded view of the heat dissipation device of
FIG. 1.
[0011] FIG. 4 is a function block diagram of the circuit of the
mobile phone of FIG. 1.
[0012] FIG. 5 is a plot of the thermal resistance versus the fan
speed of the heat dissipation device.
[0013] FIG. 6 is a flowchart illustrating a principle of fan speed
and processor power adjustment of the heat dissipation device.
DETAILED DESCRIPTION
[0014] Reference will now be made to the drawings to describe the
present embodiment of a heat dissipation device, in detail.
[0015] Referring to FIGS. 1-4, a heat dissipation device 10
according to an embodiment includes a fan 11, a fins module 12, a
heat pipe 13, a base 14, two fixing plates 15, and a control system
16.
[0016] The fan 11 is for driving airflow towards the fins module
12. The fan 11 includes a housing 111, a hub 112 and a plurality of
blades 113 radially and extending outward from the hub 112. The
housing 111 defines an air outlet 1111 at a lateral side. The hub
112 and the plurality of blades 113 are received in the housing
111.
[0017] The fins module 12 is arranged adjacent to the air outlet
1111. The fins module 12 includes a plurality of fins 121 arranged
in parallel to each other. Air channels 122 are formed between each
two neighboring fins 121. The fins 121 each define a rectangular
through hole 123 with a size matching the heat pipe 13. The through
holes 123 of the plurality of fins 121 are arranged in alignment,
thereby the heat pipe 13 can penetrate through the plurality of
fins 121 via the through holes 123.
[0018] The heat pipe 13 has a curved shape with a flat profile. The
heat pipe 13 is made of metal pipe with excellent heat conductivity
and phase-change media sealed in the metal pipe. The heat pipe 13
includes an evaporation section 131 and a condensation section
132.
[0019] The evaporation section 131 of the heat pipe 13 is thermally
attached to a central portion of the base 14 and fixed to the base
14 by the fixing plate 15. At least two temperature sensors 133 are
arranged at different positions of the evaporation section 131. At
the position where each temperature sensor 133 sits, a temperature
is sensed, and a sensed result is sent to the control system 16, by
the temperature sensor 133. The number of temperature sensors 133
can be two, three, four, or more. In this embodiment, there are
three temperature sensors 133 arranged on the evaporation section
131.
[0020] The condensation section 132 of the heat pipe 13 is
perpendicular to the evaporation section 131 and thermally
connected to the fins module 12. In addition, the condensation
section 132 penetrates through the plurality of fins 121 via the
through holes 123.
[0021] The base 14 is a flat heat conductive plate with the four
corners cut off. The base 14 has its bottom intimately attached to
a processor 17 in use. The base 14 has its top attached to the
evaporation section 131 of the heat pipe 13.
[0022] The fixing plates 15 each include a central portion 151, a
first side portion 152 and a second side portion 153. The central
portion 151 is a strip-like portion fixed with the base 14. The
first and second side portions 152, 153 respectively extend from an
end of the central portion 151 along a direction inclined to the
central portion 151. The first and second side portions 152, 153
each include a distal end, in which a through hole 154 is defined.
Accordingly, the base 14 can be fixed to a circuit board (not
illustrated) by bolts 155 penetrating through the through holes
154. In this embodiment, a plurality of gaskets 156 engage with
corresponding bolts 155 under the fixing plates 15.
[0023] Referring to FIG. 4, the control system 16 communicates with
the processor 17 and the fan 11, thereby adjusting a heat
dissipating efficiency of the heat dissipation device 10.
[0024] Referring to FIG. 5, a plot of the thermal resistance versus
the fan speed of the heat dissipation device 10 is illustrated.
When the processor 17 has a relatively low power, for example 35
watts (Q.sub.in=35 W), the thermal resistance of the heat
dissipation device 10 decreases as the fan speed increases. When
the processor 17 has a higher power, for example 40 and 45 watts
(Q.sub.in=40 W, Q.sub.in=45 W), the thermal resistance of the heat
dissipation device 10 first decreases and then increases, as the
fan speed increases. Generally, the processor 17 has an operation
power greater than 40 watts.
[0025] Referring to FIG. 6, the control system 16 is capable of
adjusting the speed of the fan 11 and the operation power of the
processor 17, according to temperatures respectively sensed by the
three temperature sensors 133. The principle of fan speed and
processor power adjustment of the heat dissipation device 10 is
described in detail as follows.
[0026] First, the three temperature sensors 133 continuously sense
temperatures S1, S2 and S3 of the respective positions where they
sit. The control system 16 respectively compares the temperatures
S1, S2 and S3 with a first critical temperature T1 which stands for
a normal operating temperature of the processor 17.
[0027] In condition that the temperatures S1, S2 and S3 are all
lower than or equal to the first critical temperature T1, the
control system 16 keeps the operation power of the processor 17
unchanged. If the temperatures S1, S2 and S3 are all lower than or
equal to the first critical temperature T1, it shows that heat
dissipating efficiency of the heat dissipation device 10
satisfactorily meets the cooling needs of the processor 17.
Accordingly, there is no need to adjust the operation power of the
processor 17.
[0028] In condition, that anyone of the temperatures S1, S2, and S3
is higher than the first critical temperature T1, the control
system 16 increases the speed of the fan 11. If anyone of the
temperatures S1, S2, and S3 is higher than the first critical
temperature T1, it shows that heat dissipating efficiency of the
heat dissipation device 10 fails to meet the cooling needs of the
processor 17. Accordingly, the speed of the fan 11 increases to
improve the heat dissipating efficiency of the heat dissipation
device 10. Successively, the control system 16 compares a
difference between S1 and S2 with a first critical temperature
difference N1, to check out whether there is a nonuniform
temperature distribution caused by drying-out of the heat pipe 13.
The first critical temperature difference N1 is defined with a
value representing a threshold of normal temperature difference
between two of the temperature sensors 133 on the heat pipe 13.
[0029] In condition that the difference between S1 and S2 is lower
than or equal to the first critical temperature difference N1
(S1-S2<N1, or S1-S2=N1), the control system 16 keeps the
operation power of the processor 17 unchanged. The condition
S1-S2<N1 or S1-S2=N1 shows that there is no nonuniform
temperature distribution on the heat pipe 13, and the heat
dissipating efficiency can be finely improved by only increasing
the speed of the fan 11. As such, there is no need to adjust the
operation power of the processor 17.
[0030] In condition that the difference between S1 and S2 is larger
than the first critical temperature difference N1 (S1-S2>N1),
the control system 16 decreases the speed of the fan 11 and then
compares the difference between S2 and S3 with a second critical
temperature difference N2. The condition S1-S2>N1 shows that
there is a nonuniform temperature distribution on the heat pipe 13,
and the heat dissipating efficiency cannot be finely improved by
increasing the speed of the fan 11. That is because the increased
speed of the fan 11 leads to higher thermal resistance of the heat
dissipation device 10. As such, the speed of the fan 11 is
decreased to reduce the thermal resistance of the heat dissipation
device 10, according to what is illustrated in FIG. 5. Then a
difference between S2 and S3 is compared with second critical
temperature difference N2 to further check whether there is a
nonuniform temperature distribution on the heat pipe 13. The second
critical temperature difference N2 is defined with a value
representing another threshold of normal temperature difference
between another two of the temperature sensors 133 on the heat pipe
13.
[0031] In condition that the difference between S2 and S3 is lower
than or equal to the second critical temperature difference N2
(S2-S3<N2, or S2-S3=N2), the control system 16 keeps the
operation power of the processor 17 unchanged. The condition
S2-S3<N2 or S2-S3=N2 shows that the nonuniform temperature
distribution on the heat pipe 13 is eliminated by decreasing the
speed of the fan 11, and it is the drying-out condition of the heat
pipe 13 which leads to former low heat dissipating efficiency. As
such, the heat dissipating efficiency can be improved by only
decreasing the speed of the fan 11 to achieve lower thermal
resistance of the heat dissipation device 10.
[0032] In condition that the difference between S2 and S3 is larger
than the second critical temperature difference N2 (S2-S3>N2),
the control system 16 decreases the speed of the fan 11 and
respectively compares the temperatures S1, S2 and S3 with a second
critical temperature T2. The condition S2-S3>N2 shows that the
thermal resistance of the heat dissipation device 10 has not been
reduced to a minimum value by decreasing the speed of the fan 11,
according to FIG. 5. As such, the speed of the fan 11 further
decreases to achieve a lower thermal resistance of the heat
dissipation device 10, and the temperatures S1, S2 and S3 with a
second critical temperature T2 to check out whether the processor
17 has been cooled to a satisfied temperature lower than or equal
to the second critical temperature T2.
[0033] In condition that the temperatures S1, S2, and S3 are all
lower than or equal to the second critical temperature T2, the
control system 16 keeps the operation power of the processor 17
unchanged. The condition that the temperatures S1, S2, and S3 are
all lower than or equal to the second critical temperature T2 shows
that, the processor 17 has been cooled to a satisfied temperature
by further decreasing the speed of the fan 11. As such, there is no
need to lower the operation power of the processor 17.
[0034] In condition, that anyone of the temperatures S1, S2, and S3
is higher than T2, the control system 16 decreases the operation
power of the processor 17. The condition that the anyone of the
temperatures S1, S2, and S3 is higher than T2 shows that, it is
impossible to cool the processor 17 to the satisfied temperature
range only by achieving lowest thermal resistance of the heat
dissipation device 10. As such, the processor 17 can only be cooled
by reducing the operation power thereof.
[0035] It is to be understood that the above-described embodiments
are intended to illustrate rather than limit the disclosure.
Variations may be made to the embodiments without departing from
the spirit of the disclosure as claimed. The above-described
embodiments illustrate the scope of the disclosure but do not
restrict the scope of the disclosure.
* * * * *