U.S. patent application number 10/987243 was filed with the patent office on 2006-05-18 for thermal component temperature management system and method.
This patent application is currently assigned to Halliburton Energy Services, Inc.. Invention is credited to Clive D. Menezes, Haoshi Song, Bruce H. Storm.
Application Number | 20060102353 10/987243 |
Document ID | / |
Family ID | 36384996 |
Filed Date | 2006-05-18 |
United States Patent
Application |
20060102353 |
Kind Code |
A1 |
Storm; Bruce H. ; et
al. |
May 18, 2006 |
Thermal component temperature management system and method
Abstract
A system for managing the temperature of a thermal component.
The system comprises a heat exchanger in thermal contact with the
thermal component. The temperature management system also comprises
a heat storing temperature management system for removing heat from
the thermal component and storing the removed heat within the heat
storing temperature management system. The temperature management
system further comprises a heat exhausting temperature management
system for removing heat from the thermal component and
transferring the removed heat to the environment outside the
temperature management system.
Inventors: |
Storm; Bruce H.; (Houston,
TX) ; Song; Haoshi; (Sugar Land, TX) ;
Menezes; Clive D.; (Conroe, TX) |
Correspondence
Address: |
CONLEY ROSE, P.C.
PO BOX 3267
HOUSTON
TX
77253-3267
US
|
Assignee: |
Halliburton Energy Services,
Inc.
Houston
TX
|
Family ID: |
36384996 |
Appl. No.: |
10/987243 |
Filed: |
November 12, 2004 |
Current U.S.
Class: |
166/302 ;
166/57 |
Current CPC
Class: |
E21B 47/017
20200501 |
Class at
Publication: |
166/302 ;
166/057 |
International
Class: |
E21B 43/24 20060101
E21B043/24; E21B 36/00 20060101 E21B036/00 |
Claims
1. A system for the temperature management of a thermal component:
a heat exchanger thermally coupled with the thermal component; a
heat storing temperature management system thermally coupled with
said heat exchanger; and a heat exhausting temperature management
system thermally coupled with said heat storing temperature
management system.
2. The system of claim 1 wherein said heat exchanger is selected
from the group consisting of a micro-capillary, cold plate heat
exchanger; a conduction heat exchanger; a multiple layer heat
exchanger; a micro-channel, cold plate heat exchanger; and a liquid
cold plate heat exchanger.
3. The system of claim 1 wherein said system and the thermal
component are in a tool selected from the group consisting of a
downhole drill string tool, a downhole wireline tool, a permanently
installed downhole tool, and a temporary well testing tool.
4. The system of claim 1 wherein said system is at least partially
contained within a thermal barrier.
5. The system of claim 1 wherein said heat storing temperature
management system removes heat from the thermal component and
stores the heat within said heat storing temperature management
system.
6. The system of claim 5 wherein said heat exhausting temperature
management system transfers heat from said heat storing temperature
management system to the environment outside the system.
7. The system of claim 6 wherein: said temperature management
system is located within a downhole tool on a drill string; and
said exhausting temperature management system transfers heat to
drilling fluid being pumped through the drill string and the
downhole tool.
8. The system of claim 1 wherein said heat storing temperature
management system comprises: a heat sink; and a thermal conduit
system thermally coupling said heat exchanger with said heat
sink.
9. The system of claim 8 wherein said thermal conduit system
thermally couples said heat exchanger with said heat sink via at
least one of conduction, convection, and radiation.
10. The system of claim 8 wherein said heat sink comprises a phase
change material.
11. The system of claim 10 wherein said phase change material
comprises a eutectic material.
12. The system of claim 8 wherein said thermal conduit system
comprises a thermally conductive material.
13. The system of claim 12 wherein the thermal component is
immersed in a fluid.
14. The system of claim 8 wherein said thermal conduit system
comprises a coolant fluid conduit system for the flow of a coolant
fluid.
15. The system of claim 14 wherein the thermal component is
immersed in a fluid.
16. The system of claim 14 wherein the thermal component is
immersed is said coolant fluid.
17. The system of claim 8 wherein said heat storing temperature
management system transfers heat from the thermal component to said
heat sink.
18. The system of claim 8 further comprising a control system that
operates said heat exhausting temperature management system when
the temperature of said heat sink is equal to or greater than a
predetermined threshold.
19. The system of claim 1 wherein said heat exhausting temperature
management system comprises a thermoelectric cooler comprising a
hot plate and a cold plate.
20. The system of claim 19 wherein said heat exhausting temperature
management system comprises a multiple stage thermoelectric
temperature management system.
21. The system of claim 1 wherein said heat exhausting temperature
management system is selected from the group consisting of a
thermoacoustic cooler and a vapor compression temperature
management system.
22. The system of claim 1 further comprising a control system that
operates said heat exhausting temperature management system when
the temperature of the thermal component is equal to or greater
than a predetermined threshold.
23. A system for managing the temperature of a thermal component
comprising: a first heat exchanger thermally coupled with the
thermal component; a heat storing temperature management system
thermally coupled with said first heat exchanger; a second heat
exchanger thermally coupled with the thermal component; and a heat
exhausting temperature management system thermally coupled with
said second heat exchanger.
24. The system of claim 23 wherein said first and second heat
exchangers are selected from the group consisting of a
micro-capillary, cold plate heat exchanger; a conduction heat
exchanger; a multiple layer heat exchanger; a micro-channel, cold
plate heat exchanger; and a liquid cold plate heat exchanger.
25. The system of claim 23 wherein the system and the thermal
component are in a tool selected from the group consisting of a
downhole drill string tool, a downhole wireline tool, a permanently
installed downhole tool, and a temporary well testing tool.
26. The system of claim 23 wherein the system is at least partially
contained within a thermal barrier.
27. The system of claim 23 wherein said heat storing temperature
management system removes heat from the thermal component and
stores the heat within said heat storing temperature management
system.
28. The system of claim 27 wherein said heat exhausting temperature
management system transfers heat from the thermal component to the
environment outside the system.
29. The system of claim 28 wherein: said system is located within a
downhole tool on a drill string; and said exhausting temperature
management system transfers heat to drilling fluid being pumped
through the drill string and the downhole tool.
30. The system of claim 23 wherein said heat storing temperature
management system comprises: a heat sink; and a thermal conduit
system thermally coupling said first heat exchanger with said heat
sink.
31. The system of claim 30 wherein said thermal conduit system
thermally couples said first heat exchanger with said heat sink via
at least one of conduction, convection, and radiation.
32. The system of claim 30 wherein said heat sink comprises a phase
change material.
33. The system of claim 32 wherein said phase change material
comprises a eutectic material.
34. The system of claim 30 wherein said thermal conduit system
comprises a thermally conductive material.
35. The system of claim 34 wherein the thermal component is
immersed in a fluid.
36. The system of claim 30 wherein said thermal conduit system
comprises a coolant fluid conduit system for the flow of a coolant
fluid.
37. The system of claim 36 wherein the thermal component is
immersed in a fluid.
38. The system of claim 36 wherein the thermal component is
immersed is said coolant fluid.
39. The system of claim 30 wherein said heat storing temperature
management system transfers heat from the thermal component to said
heat sink.
40. The system of claim 30 further comprising a control system that
operates said heat exhausting temperature management system when
the temperature of said heat sink is equal to or greater than a
predetermined threshold.
41. The system of claim 23 wherein said heat exhausting temperature
management system comprises a thermoelectric cooler comprising a
hot plate and a cold plate.
42. The system of claim 41 wherein said heat exhausting temperature
management system comprises a multiple stage thermoelectric
temperature management system.
43. The system of claim 23 wherein said heat exhausting temperature
management system is selected from the group consisting of a
thermoacoustic cooler and a vapor compression temperature
management system.
44. The system of claim 23 further comprising a control system that
operates said heat exhausting temperature management system when
the temperature of the thermal component is equal to or greater
than a predetermined threshold.
45. A system for managing the temperature of a thermal component
comprising: a heat exchanger thermally coupled with the thermal
component; a heat storing temperature management system thermally
coupled with said first heat exchanger; and a heat exhausting
temperature management system thermally coupled with said heat
exchanger.
46. The system of claim 45 wherein said heat exchanger is selected
from the group consisting of a micro-capillary, cold plate heat
exchanger; a conduction heat exchanger; a multiple layer heat
exchanger; a micro-channel, cold plate heat exchanger; and a liquid
cold plate heat exchanger.
47. The system of claim 45 wherein the system and the thermal
component are in a tool selected from the group consisting of a
downhole drill string tool, a downhole wireline tool, a permanently
installed downhole tool, and a temporary well testing tool.
48. The system of claim 45 wherein the system is at least partially
contained within a thermal barrier.
49. The system of claim 45 wherein said heat storing temperature
management system removes heat from the thermal component and
stores the heat within said heat storing temperature management
system.
50. The system of claim 49 wherein said heat exhausting temperature
management system transfers heat from the thermal component to the
environment outside the temperature management system.
51. The system of claim 50 wherein: said system is located within a
downhole tool on a drill string; and said exhausting temperature
management system transfers heat to drilling fluid being pumped
through the drill string and the downhole tool.
52. The system of claim 45 wherein said heat storing temperature
management system comprises: a heat sink; and a thermal conduit
system thermally coupling said heat exchanger with said heat
sink.
53. The system of claim 52 wherein said thermal conduit system
thermally couples said heat exchanger with said heat sink via at
least one of conduction, convection, and radiation.
54. The system of claim 52 wherein said heat sink comprises a phase
change material.
55. The system of claim 54 wherein said phase change material
comprises a eutectic material.
56. The system of claim 52 wherein said thermal conduit system
comprises a thermally conductive material.
57. The system of claim 56 wherein the thermal component is
immersed in a fluid.
58. The system of claim 52 wherein said thermal conduit system
comprises a coolant fluid conduit system for the flow of a coolant
fluid.
59. The system of claim 58 wherein the thermal component is
immersed in a fluid.
60. The system of claim 58 wherein the thermal component is
immersed is said coolant fluid.
61. The system of claim 52 wherein said heat storing temperature
management system transfers heat from the thermal component to said
heat sink.
62. The system of claim 52 further comprising a control system that
operates said heat exhausting temperature management system when
the temperature of said heat sink is equal to or greater than a
predetermined threshold.
63. The system of claim 45 wherein said heat exhausting temperature
management system comprises a multiple stage thermoelectric
temperature management system.
64. The system of claim 63 wherein said heat exhausting temperature
management system comprises a thermoelectric temperature management
system.
65. The system of claim 45 wherein said heat exhausting temperature
management system is selected from the group consisting of a
thermoacoustic cooler and a vapor compression temperature
management system.
66. The system of claim 45 further comprising a control system that
operates said heat exhausting temperature management system when
the temperature of the thermal component is equal to or greater
than a predetermined threshold.
67. A system for managing the temperature of a thermal component
comprising: a first heat exchanger thermally coupled with the
thermal component; a heat storing temperature management system
thermally coupled with said first heat exchanger; said heat storing
temperature management system comprising a thermal conduit system;
and a heat exhausting temperature management system thermally
coupled with said thermal conduit system.
68. The system of claim 67 wherein said heat exchanger is selected
from the group consisting of a micro-capillary, cold plate heat
exchanger; a conduction heat exchanger; a multiple layer heat
exchanger; a micro-channel, cold plate heat exchanger; and a liquid
cold plate heat exchanger.
69. The system of claim 67 wherein said system and the thermal
component are in a tool selected from the group consisting of a
downhole drill string tool, a downhole wireline tool, a permanently
installed downhole tool, and a temporary well testing tool.
70. The system of claim 67 wherein said system is at least
partially contained within a thermal barrier.
71. The system of claim 67 wherein said heat storing temperature
management system removes heat from the thermal component and
stores the heat within said heat storing temperature management
system.
72. The system of claim 74 wherein said heat exhausting temperature
management system transfers heat from said thermal conduit system
to the environment outside the temperature management system.
73. The system of claim 72 wherein: said system is located within a
downhole tool on a drill string; and said exhausting temperature
management system transfers heat to drilling fluid being pumped
through the drill string and the downhole tool.
74. The system of claim 72 wherein said heat exhausting temperature
management system is thermally coupled with said heat
exchanger.
75. The system of claim 67 wherein said heat storing temperature
management system comprises a heat sink thermally coupled with said
heat exchanger through said thermal conduit system.
76. The system of claim 75 wherein said thermal conduit system
thermally couples said heat exchanger with said heat sink via at
least one of conduction, convection, and radiation.
77. The system of claim 75 wherein said heat sink comprises a phase
change material.
78. The system of claim 77 wherein said phase change material
comprises a eutectic material.
79. The system of claim 78 wherein said thermal conduit system
comprises a thermally conductive material.
80. The system of claim 79 wherein the thermal component is
immersed in a fluid.
81. The system of claim 75 wherein said thermal conduit system
comprises a coolant fluid conduit system for the flow of a coolant
fluid.
82. The system of claim 81 wherein the thermal component is
immersed in a fluid.
83. The system of claim 81 wherein the thermal component is
immersed is said coolant fluid.
84. The system of claim 75 wherein said heat storing temperature
management system transfers heat from the thermal component to said
heat sink.
85. The system of claim 75 further comprising a control system that
operates said heat exhausting temperature management system when
the temperature of said heat sink is equal to or greater than a
predetermined threshold.
86. The system of claim 67 wherein said heat exhausting temperature
management system comprises a thermoelectric cooler comprising a
hot plate and a cold plate.
87. The system of claim 86 wherein said heat exhausting temperature
management system comprises a multiple stage thermoelectric
temperature management system.
88. The system of claim 67 wherein said heat exhausting temperature
management system is selected from the group consisting of a
thermoacoustic cooler and a vapor compression temperature
management system.
89. The system of claim 67 further comprising a control system that
operates said heat exhausting temperature management system when
the temperature of the thermal component is equal to or greater
than a predetermined threshold.
90. A method of managing the temperature of a thermal component
comprising: removing heat from the thermal component with a heat
exhausting temperature management system; powering said heat
exhausting temperature management system with a power source; and
removing heat from the thermal component with a heat storing
temperature management system at least when said power source is
not operating.
91. The method of claim 90 further comprising removing heat from a
thermal component in a tool selected from the group consisting of a
downhole drill string tool, a downhole wireline tool, a permanently
installed downhole tool, and a temporary well testing tool.
92. The method of claim 90 wherein removing heat with said heat
storing temperature management system comprises: thermally coupling
said heat storing temperature management system to the thermal
component using a heat exchanger; removing heat from the thermal
component through the heat exchanger with said heat storing
temperature management system; and storing the heat removed by said
heat storing temperature management system in a heat sink within
said heat storing temperature management system.
93. The method of claim 90 wherein removing heat with said heat
exhausting temperature management system comprises: thermally
coupling said heat exhausting temperature management system with
said heat storing temperature management system; removing heat from
said heat storing temperature management system with said heat
exhausting temperature management system; and storing the heat
removed by said heat exhausting temperature management system to
the environment outside the temperature management system.
94. The system of claim 93 wherein transferring the heat removed by
said heat exhausting temperature management system comprises
transferring heat to drilling fluid being pumped through a drill
string and a downhole tool.
95. The method of claim 93 wherein removing heat from said heat
storing temperature management system comprises: thermally coupling
said heat exhausting temperature management system to said heat
sink; and removing heat from said heat sink.
96. The method of claim 93 wherein removing heat from said heat
storing temperature management system comprises: thermally coupling
said heat exhausting temperature management system to a thermal
conduit system of said heat storing temperature management system;
and removing heat from said thermal conduit system.
97. The method of claim 90 wherein removing heat from the thermal
component with a heat exhausting temperature management system
comprises: thermally coupling said heat exhausting temperature
management system to the thermal component; removing heat from the
thermal component with said heat exhausting temperature management
system; and transferring the heat removed by said heat exhausting
temperature management system to the environment outside the
temperature management system.
98. The system of claim 97 wherein transferring the heat removed by
said heat exhausting temperature management system comprises
transferring heat to drilling fluid being pumped through a drill
string and a downhole tool.
99. The method of claim 90 further comprising thermally coupling
said heat exhausting temperature management system to the thermal
component with a second heat exchanger.
100. The method of claim 90 wherein removing heat from the thermal
component with said heat exhausting temperature management system
further comprises removing heat with at least one of a
thermoelectric cooler, a thermoacoustic cooler, and a vapor
compression temperature management system.
101. The method of claim 90 further comprising retarding heat flow
to the thermal component with a thermal barrier.
102. The method of claim 90 wherein the thermal component is in an
environment with a higher temperature than the thermal
component.
103. The method of claim 90 further comprising operating said heat
exhausting temperature management system with a control system that
operates said heat exhausting temperature management system when
the temperature of the thermal component is equal to or greater
than a predetermined threshold.
104. The method of claim 90 further comprising: storing the heat
removed by said heat storing temperature management system in a
heat sink within said heat storing temperature management system;
and operating said heat exhausting temperature management system
with a control system that operates said heat exhausting
temperature management system when the temperature of said heat
sink is equal to or greater than a predetermined threshold.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable.
BACKGROUND OF THE INVENTION
[0003] To drill a well, a drill bit bores thousands of feet into
the crust of the earth. The drill bit typically extends downward
from a drilling platform on a string of pipe, commonly referred to
as a "drill string." The drill string may be jointed pipe or coiled
tubing, through which drilling fluid is pumped to cool and
lubricate the bit and lift the drill cuttings to the surface. At
the lower, or distal, end of the drill string is a bottom hole
assembly (BHA), which includes, among other components, the drill
bit.
[0004] In order to obtain measurements and information from the
downhole environment while drilling, the BHA includes electronic
instrumentation. Various tools on the drill string, such as
logging-while-drilling (LWD) tools and measurement-while-drilling
(MWD) tools incorporate the instrumentation. Such tools on the
drill string contain various electronic components incorporated as
part of the BHA. These electronic components generally consist of
computer chips, circuit boards, processors, data storage, power
converters, and the like.
[0005] Downhole tools must be able to operate near the surface of
the earth as well as many thousands of feet below the surface.
Environmental temperatures tend to increase with depth during the
drilling of the well. As the depth increases, the tools are
subjected to a severe operating environment. For example, downhole
temperatures are generally high and may even exceed 200.degree. C.
In addition, pressures may exceed 20,000 psi. There is also
vibration and shock stress associated with operating in the
downhole environment, particularly during drilling operations.
[0006] The electronic components in the downhole tools also
internally generate heat. For example, a typical wireline tool may
dissipate over 100 watts of power, and a typical downhole tool on a
drill string may dissipate over 10 watts of power. While performing
drilling operations, the tools on the drill string typically remain
in the downhole environment for periods of several weeks. In other
downhole applications, drill string electronics may remain downhole
for as short as several hours to as long as one year. For example,
to obtain downhole measurements, tools are lowered into the well on
a wireline or a cable. These tools are commonly referred to as
"wireline tools." However, unlike in drilling applications,
wireline tools generally remain in the downhole environment for
less than twenty-four hours.
[0007] A problem with downhole tools is that when downhole
temperatures exceed the temperature of the electronic components,
the heat cannot dissipate into the environment. The heat may
accumulate internally within the electronic components and this may
result in a degradation of the operating characteristics of the
component or may result in a failure. Thus, two general heat
sources must be accounted for in downhole tools, the heat incident
from the surrounding downhole environment and the heat generated by
the tool components, e.g., the tool's electronics components.
[0008] While the temperatures of the downhole environment may
exceed 200.degree. C., the electronic components are typically
rated to operate at no more than 125.degree. C. Thus, exposure of
the tool to elevated temperatures of the downhole environment and
the heat dissipated by the components may result in the degradation
of the thermal failure of those components. Generally, thermally
induced failure has at least two modes. First, the thermal stress
on the components degrades their useful lifetime. Second, at some
temperature, the electronics may fail and the components may stop
operating. Thermal failure may result in cost not only due to the
replacement costs of the failed electronic components, but also
because electronic component failure interrupts downhole
activities. Trips into the borehole also use costly rig time.
[0009] In general, there are at least two methods for managing the
temperature of thermal components in a downhole tool. One method is
a heat storing temperature management system. Heat storing
temperature management involves removing heat from the thermal
component and storing the heat in another element of the heat
storing temperature management system, such as a heat sink. Another
method is a heat exhausting temperature management system. Heat
exhausting temperature management involves removing heat from the
thermal component and transferring the heat to the environment
outside the heat exhausting temperature management system. The heat
may be transferred to the drill string or to the drilling fluid
inside or outside the drill string.
[0010] A traditional method of managing the temperature of thermal
components in a downhole tool using a heat exhausting system
involves modest environmental temperatures such that the
electronics operate at a temperature above the environmental
temperature. In modest environments, the electronics may be
thermally connected to the tool housing. The thermal connection
allows the heat to dissipate to the environment by the natural heat
transfer of conduction, convection, and/or radiation. This approach
is limited by the temperature gradient between the electronics and
the environment.
[0011] A traditional method of managing the temperature of thermal
components in a downhole tool using a heat storage system in harsh
thermal environments is to place the electronics on a chassis in an
insulated vacuum flask. The vacuum flask acts as a thermal barrier
to retard heat transfer from the downhole environment to the
electronics. However, thermal flasks are heat storage systems that
only slow the harmful effects of thermal failure. Because of the
extended periods downhole in both wireline and drilling operations,
insulated flasks may not provide sufficient thermal management for
the electronic components for extended periods. Specifically, the
flask does not remove the heat generated internally by the
electronic components. A thermal mass, such as a eutectic material,
can be included in the flask to absorb heat from the downhole
environment as well as the heat generated internally by the
electronics. However, both the thermal flask and the thermal mass
are only used to thermally manage the temperature of the interior
of the electronics compartment. Because the discrete components may
internally generate heat, they may remain at a higher temperature
than the average temperature of the interior of the electronics
compartment. Thus, although the average temperature of the interior
of the compartment may remain at a desired level, discrete
components may exceed their desired operating temperatures.
[0012] Another temperature management method for downhole
electronics proposes a vapor compression temperature management
system using water or other suitable liquid; e.g., FREON.RTM.. In
this method, liquid in one tank is thermally coupled with the
electronics chassis of the downhole tool. The liquid absorbs heat
via the heat exchanger from the downhole environment and the
electronics, where the electronics are isolated from the liquid,
and begins to vaporize. For example, water would begin to vaporize
at 100.degree. C. so long as the pressure of the tank is maintained
at 1.01.times.10.sup.5 Pa (14.7 psi). To maintain the pressure, the
steam is removed from the tank and compressed and stored in a
second tank, which is at or near the temperature of the downhole
environment. However, sufficient steam must be removed from the
first tank with a compressor to maintain the pressure at
1.01.times.10.sup.5 Pa. Otherwise, the boiling point of the liquid
will rise and thus raise the temperature of the electronics chassis
in the first tank.
[0013] In practice, vaporization temperature management has
significant problems. First, a compressor must be supplied that is
able to compress the vapor to a pressure greater than the
saturation pressure of the vapor at the temperature of the downhole
environment; e.g., 1.55.times.10.sup.6 Pa (225 psi) at 200.degree.
C. for water. Second, the method does not isolate the thermal
components but instead attempts to cool the entire electronics
region. While the average temperature of the region may remain at
100.degree. C., the temperature of the discrete electronic
components may be higher because they may internally generate heat.
Additionally, due to the typically low efficiency of most
temperature management systems and the typically relatively high
amount of heat to be extracted, substantial power may be required
by the system. This power is typically provided from downhole power
generation devices such as turbine alternators. However, the
downhole power generation devices are typically powered by drilling
fluid being pumped through the inside of the drill string during
drilling. At times during the drilling process, the pumping may be
stopped to perform various tasks such as adding pipe to or removing
pipe from the drill string. When the pumping is stopped, the
downhole power generation devices are unable to supply power to the
heat exhausting temperature management system. Thus, although
temperature management is still required, those heat exhausting
temperature management systems that require a source of power are
unable to cool the thermal components when pumping is stopped
because of the loss of power. Even if batteries are provided
downhole, they are limited in the duration for which they can
provide power to the heat exhausting temperature management
system.
[0014] Another temperature management method proposes a sorbent
temperature management system. This method again uses the
evaporation of a liquid that is thermally connected via heat
exchanger with the thermal components to manage the temperature of
the components. Instead of using a compressor to remove the vapor,
this method uses desiccants in a second tank to absorb the vapor as
it evaporates in a first tank, thus providing heat storage while
requiring no input power. However, the desiccants must absorb
sufficient vapor in order to maintain a constant pressure in the
first tank. Otherwise, the boiling point of the liquid will rise as
the pressure in the lower tank rises.
[0015] However, prior sorbent temperature management systems manage
the temperature of the entire electronics region, not the discrete
thermal components. Thus, because of internal heat generation, the
thermal components may remain at a higher temperature than the
average temperature of the entire thermal component region. Second,
the desiccants must absorb sufficient vapor in order to maintain a
constant pressure in the first tank. Otherwise, the liquid will
evaporate at a higher temperature and thus the temperature in the
first tank will increase. Further, the amount of water in the first
tank limits the system. Once all the water evaporates, the system
no longer functions.
[0016] Another heat exhausting temperature management method
involves a downhole thermoelectric refrigeration system comprising
a cold heat exchanger and a hot heat exchanger thermally coupled by
semiconductor materials. With the thermoelectric refrigeration
system, the cold heat exchanger of the temperature management
system is thermally coupled with the thermal components.
[0017] Due to the typically low efficiency of thermoelectric
refrigeration temperature management systems and the typically
relatively high amount of heat to be extracted, substantial power
is required by the temperature management system. This power can
typically only be provided from downhole power generation devices
such as turbines and alternators. However, the downhole power
generation devices are typically powered by drilling fluid being
pumped through the inside of the drill string during drilling. At
times during the drilling process, the pumping is stopped to
perform various tasks such as adding pipe to or removing pipe from
the drill string. When the pumping is stopped, the downhole power
generation devices are unable to supply power to the heat
exhausting temperature management system. Thus, although
temperature management is still required, the thermoelectric
refrigeration systems are unable to cool the thermal components
when pumping is stopped because of the loss of power. Even if
batteries are provided downhole, they are limited in the duration
for which they can provide power to the thermoelectric
refrigeration system.
[0018] Another temperature management method involves a downhole
thermoacoustic temperature management system. An example of a
downhole thermoacoustic temperature management system is described
in U.S. Pat. No. 5,165,243, issued Nov. 24, 1992 and entitled
"Compact Acoustic Refrigerator", hereby incorporated herein by
reference for all purposes. The compact acoustic refrigeration
system cools components, e.g., electrical circuits, in a downhole
environment. The system includes an acoustic engine that includes
first thermodynamic elements for generating a standing acoustic
wave in a selected medium. The system also includes an acoustic
refrigerator that includes second thermodynamic elements located in
the standing wave for generating a relatively cold temperature at a
first end of the second thermodynamic elements and a relatively hot
temperature at a second end of the second thermodynamic elements. A
resonator volume cooperates with the first and second thermodynamic
elements to support the standing wave. To accommodate the high heat
fluxes required for heat transfer to/from the first and second
thermodynamic elements, first heat pipes transfer heat from the
heat load to the second thermodynamic elements and second heat
pipes transfer heat from the first and second thermodynamic
elements to the downhole environment.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] For a more detailed description of the embodiments,
reference will now be made to the following accompanying
drawings:
[0020] FIG. 1 is a schematic view illustrating a temperature
management system according to a first embodiment;
[0021] FIG. 2 is a schematic view of a thermoelectric cooler
optionally used in the temperature management system of FIG. 1;
[0022] FIG. 3 is a flow chart representing a control system for the
heat exhausting temperature management system of the temperature
management system of FIG. 1;
[0023] FIG. 4 is a schematic view illustrating a second embodiment
temperature management system;
[0024] FIG. 5 is a schematic view illustrating a third embodiment
temperature management system; and
[0025] FIG. 6 is a schematic view illustrating a fourth embodiment
temperature management system.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0026] The present invention relates to a thermal component
temperature management system and includes embodiments of different
forms. The drawings and the description below disclose specific
embodiments with the understanding that the embodiments are to be
considered an exemplification of the principles of the invention,
and are not intended to limit the invention to that illustrated and
described. Further, it is to be fully recognized that the different
teachings of the embodiments discussed below may be employed
separately or in any suitable combination to produce desired
results. The term "couple", "couples", or "thermally coupled" as
used herein is intended to mean either an indirect or a direct
connection. Thus, if a first device couples to a second device,
that connection may be through a direct connection; e.g., via
conduction through one or more devices, or through an indirect
connection; e.g., via convection or radiation. The term
"temperature management" as used herein is intended to mean the
overall management of temperature, including maintaining,
increasing, or decreasing temperature and is not meant to be
limited to only decreasing temperature.
First Embodiment
[0027] FIG. 1 illustrates a first embodiment of a temperature
management system 10 disposed in a downhole tool 14 such as on a
drill string 16 for drilling a borehole 13 in a formation 17. The
temperature management system 10 might also be used in a downhole
wireline tool, a permanently installed downhole tool, or a
temporary well testing tool. Downhole, the ambient temperature may
sometimes exceed 200.degree. C. However, the temperature management
system 10 may also be used in other situations and applications
where the surrounding environment ambient temperature is either
greater than or less than that of the thermal components being
cooled.
[0028] The temperature management system 10 manages the temperature
of at least one thermal component 12 that may, e.g., be mounted on
at least one board 18 in the downhole tool 14. The thermal
component 12 comprises, but is not limited to, heat-dissipating
components, heat-generating components, and/or heat-sensitive
components. An example of a thermal component 12 may be an
integrated circuit, e.g., a computer chip, or other electrical or
mechanical device that is heat-sensitive or whose performance is
deteriorated by high temperature operation, or that generates heat.
The board 18 is in turn mounted on a chassis (not illustrated) and
installed within a cavity 15 of the downhole tool 14.
[0029] Heat Exchanger
[0030] The temperature management system 10 further comprises a
heat exchanger 20 thermally coupled with the thermal component 12.
In one embodiment, the heat exchanger 20 is thermally coupled via a
conductive path to the thermal component 12. However, in other
embodiments, the heat exchanger 20 may be thermally coupled with
the thermal component 12 by radiation or convection. The heat
exchanger 20 may be any appropriate type of heat exchanger, such as
a conduction heat exchanger that uses heat conduction to transfer
the heat through solids. The heat exchanger 20 may also comprise
multiple layers of different materials, e.g., copper flow tubes
with aluminum fins or plates. The heat exchanger 20 may also be a
micro-capillary heat exchanger. The micro-capillary heat exchanger
may also be a micro-channel, cold plate heat exchanger with stacked
plates enclosed in a housing. The heat exchanger may also be a
liquid cold plate heat exchanger.
[0031] Heat Storing Temperature Management System
[0032] The temperature management system 10 further comprises a
heat storing temperature management system 11 thermally coupled
with the heat exchanger 20. The heat storing temperature management
system 11 removes heat from the thermal component 12 through the
heat exchanger 20 and stores the removed heat in within the heat
storing temperature management system 11. The heat storing
temperature management system 11 comprises a heat sink 22
comprising a phase change material for storing the removed heat.
The phase change material is designed to take advantage of the heat
absorbed during the phase change at certain temperature ranges;
e.g., a eutectic material. Eutectic material is an alloy having a
component composition designed to achieve a desired melting point
for the material. The desired melting point takes advantage of
latent heat of fusion to absorb energy. Latent heat is the energy
absorbed by the material as it changes phase from solid into
liquid. Thus, when the material changes its physical state, it
absorbs energy without a change in the temperature of the material.
Therefore, additional heat will only change the phase of the
material, not its temperature. To take advantage of the latent heat
of fusion, the eutectic material may have a melting point below the
desired maintenance temperature of the thermal component 12. The
heat sink 22 may also comprise other types of thermal mass, such as
copper, to store removed heat.
[0033] The heat sink 22 may be stored in a jacket 24 capable of
withstanding downhole temperatures and shock conditions. For
example, the jacket 24 can be a stainless steel container. Because
the heat sink 22 may undergo a phase change, the jacket 24 may also
be capable of withstanding the contraction and/or expansion of the
heat sink 22.
[0034] Thermal Conduit System
[0035] The heat storing temperature management system 11 also
comprises a thermal conduit system 26 for thermally coupling the
heat exchanger 20 and the heat sink 22. The temperature gradient
between thermal component 12 and the heat sink 22 is such that the
heat sink 22 absorbs the heat from the thermal component 12 through
the heat exchanger 20 and the thermal conduit system 26. The
thermal conduit system 26 comprises a thermally conductive material
for transferring heat from the heat exchanger 20 to the heat sink
22. The thermal conduit system 26 may alternatively comprise a
coolant fluid conduit system that transfers the removed heat using
a coolant fluid in a closed-loop or an open-loop system. The
coolant fluid is thermally coupled to the heat exchanger 20 and the
heat sink 22 and transfers heat absorbed from the heat exchanger 20
to the heat sink 22, returning the coolant fluid to a lower
temperature. The thermal conduit system 26 maintains the coolant
fluid separate from the heat sink 22 material. The path of the
thermal conduit system 26 through the heat sink 22 may be straight
or tortuous depending on the performance specifications of the
temperature management system 10. For example, the thermal conduit
system 26 may flow helically into the heat sink 22, reverse, and
then flow helically out of the heat sink 22. The thermal conduit
system 26 may also transfer heat to the heat sink 22 using any
other suitable means. The fluid may be moved within the thermal
conduit system 26 using a fluid transfer device, e.g., a fluid
pump. Alternatively, the fluid in the thermal conduit system 26
flows via convection, i.e., by maintaining a temperature
differential between any two-points in the system. The thermal
component 12 may be immersed in fluid, e.g., water or a fluorinated
organic compound, e.g., FLUORINERT.RTM., or any other thermally
conductive fluid. The fluid the thermal component 12 is immersed in
need not be the same fluid as the coolant fluid in the thermal
conduit system 26. For example, the thermal component 12 may be
immersed in silicone oil or any other suitable fluid. Additionally,
the thermal component 12 may be immersed in a fluid regardless of
whether the thermal conduit system 26 is a fluid thermal conduit
system. The fluid thermal conduit system 26 may be a single-phase
or multiple-phase system. Examples of thermal conduit systems are
discussed in U.S. patent application Ser. No. 10/602,236, filed
Jun. 24, 2003 and entitled "Method and Apparatus for Managing the
Temperature of Thermal Components", hereby incorporated herein by
reference for all purposes. Alternatively, the thermal conduit
system may thermally couple more than one thermal component 12 to
the heat sink 22. Also alternatively, the heat removed from the
thermal component 12 may be absorbed directly by the heat sink 22;
e.g., via conduction by being in contact with the heat exchanger,
or via convection or radiation from the heat exchanger to the heat
sink.
[0036] Thus, with the exception of the alternatives requiring a
fluid transfer device, the heat storing temperature management
system 11 requires no power to remove heat from the thermal
component 12. Even with the fluid transfer device, the heat storing
temperature management system 11 would require low amounts of
power, e.g., less than 500 mw, and would be able to operate for
approximately 9 hours on a conventional 9 volt battery.
[0037] Heat Exhausting Temperature Management System
[0038] The temperature management system 10 also comprises a heat
exhausting temperature management system 40 thermally coupled with
the heat storing temperature management system 11. The heat
exhausting temperature management system 40 removes heat from the
heat storing temperature management system 11 and transfers the
heat to the environment outside the temperature management system
10.
[0039] In one embodiment, as illustrated in FIG. 2, the heat
exhausting temperature management system 40 comprises a
thermoelectric cooler comprising, e.g., a hot plate 46 and a cold
plate 44. The heat exhausting temperature management system 40 may
also comprise a multiple stage thermoelectric temperature
management system. The thermoelectric cooler 40 comprises two
different types of semiconductors 40' and 40'', such as a p-type
semiconductor and an n-type semiconductor, respectively, sandwiched
between the cold plate 44 and the hot plate 46. In one embodiment,
the cold plate 44 and the hot plate 46 may be made from a ceramic
material. The semiconductors 40' and 40'' are connected
electrically in series and thermally in parallel. A power source 36
provides energy for the thermoelectric cooler 40. When a positive
voltage from the power source 36 is applied to the n-type
semiconductor 40'', electrons pass from the low energy p-type
semiconductor 40' to the high energy n-type semiconductor 40''. In
so doing, the electrons absorb energy (i.e., heat). As the
electrons pass from the high energy n-type semiconductor 40'' to
the low energy p-type semiconductor 40', heat is expelled. Thus,
heat energy 48 is initially transferred from a heat source to the
cold junction, or cold plate 44. This heat is then transferred by
the semiconductors to the hot junction, or hot plate 46. The heat
transferred is proportional to the current and the number of
thermoelectric couples. From the hot plate 46, the heat is
transferred to the environment outside the temperature management
system 10. The heat may be transferred to the drill string 16, the
annulus 52 between the downhole tool 14 and the formation 17, or
the drilling fluid being pumped through the drill string 16 and the
downhole tool 14. The heat may be transferred from the hot plate 46
to the environment directly through conduction or indirectly
through convection or radiation, or any combination of direct and
indirect transfer. As used herein, the term "thermoelectric cooler"
includes both a single stage thermoelectric cooler, as well as
multistage and cascade arrangements of multiple thermoelectric
cooler stages.
[0040] The cold plate 44 of the heat exhausting temperature
management system 40 is thermally coupled with the heat sink 22 of
the heat storing temperature management system 11. The heat
exhausting temperature management system 40 removes heat from the
heat sink 22 at the cold plate 44 and transfers the removed heat to
the hot plate 46. From the hot plate 46, the heat is then
transferred to the environment outside the temperature management
system 10. The heat may be transferred to the drill string 16, the
drilling fluid traveling in the annulus 52 between the downhole
tool 14 and the formation 17, or the drilling fluid being pumped
through the drill string 16 and the downhole tool 14. The heat may
be transferred from the hot plate 46 to the environment through
conduction or through convection or radiation, or any combination
of direct and indirect transfer. The heat exhausting temperature
management system 40 allows removed heat to be transferred to the
drilling fluid even though the drilling fluid may be at a higher
temperature than the thermal component 12. The heat exhausting
temperature management system 40 may also comprise more than one
thermoelectric cooler thermally coupled with the heat storing
temperature management system 11. Instead of a thermoelectric
cooler, alternatively the heat exhausting temperature management
system 40 may comprise a thermoacoustic system, a vapor compression
system, or other suitable heat pumping device.
[0041] Power for the thermal component 12 and the thermoelectric
cooler 40 may be supplied by a turbine alternator 42, which is
driven by the drilling fluid pumped through the drill string 16.
The turbine alternator 16 may be of the axial, radial, or mixed
flow type. Alternatively, the alternator 42 may be driven by a
positive displacement motor driven by the drilling fluid, such as a
Moineau-type motor.
[0042] If the heat exhausting temperature management system 40 is
powered primarily by, e.g., the turbine alternator 42, it may
operate during pumping of drilling fluid through the drill string
16 and for short time periods with the pumps off. With the pumps
on, the heat exhausting temperature management system 40 removes
heat from the heat storing temperature management system 11 and
allows the temperature management system 10 to maintain heat
removal from the thermal component 12. There are, however, periods
when drilling fluid is not pumped through the drill string 16.
During these times, the heat exhausting temperature management
system 40 may not be operational, unless there is some other source
of power. However, even if the heat exhausting temperature
management system 40 is not operating, the heat storing temperature
management system 11 is able to remove heat from the thermal
component 12 and store the removed heat the heat sink 22. Once
drilling fluid flow is restored, the heat exhausting temperature
management system 40 will then remove the stored removed heat from
the heat sink 22. Thus, the heat storing temperature management
system 11 and the heat exhausting temperature management system 40
combine to manage the temperature of the thermal component 12.
[0043] Alternatively, when the power source 36 is on, the heat
exhausting temperature management system 40 may be operated by a
control system that determines when the heat exhausting temperature
management system 40 operates. The control system is represented by
the flow chart shown in FIG. 3. With reference to the flow chart
shown in FIG. 3, the heat exhausting temperature management system
40 may remain in the off state until the temperature of the
heatsink (T.sub.Heatsink), or some other monitored component, e.g.,
a thermal component 12, reaches a predetermined setpoint
temperature (T.sub.Setpoint). Thus, even though the power source 36
is providing power, the control system dictates whether the heat
exhausting temperature management system 40 operates based on the
monitored criteria.
[0044] Thermal Barrier
[0045] The temperature management system 10 may alternatively
further comprise a thermal barrier 50 enclosing the heat storing
temperature management system 11, the heat exchanger 20, and the
thermal component 12. The thermal barrier 50 thus separates the
heat storing temperature management system 11, the heat exchanger
20, and the thermal component 12 from the downhole environment. The
thermal barrier 50 may also enclose only a portion of the heat
storing temperature management system 11. The thermal barrier 50
hinders heat transfer from the outside environment to the heat
storing temperature management system 11 and the thermal component
12. By way of non-limiting example, the barrier 50 may be an
insulated vacuum "flask", a vacuum "flask" filled with an
insulating solid, a material-filled chamber, a gas-filled chamber,
a fluid-filled chamber, or any other suitable barrier. In addition,
the space 52 between the thermal barrier 50 and the tool 14 may be
evacuated. Creating a vacuum aids in hindering heat transfer to the
temperature management system 10 and the thermal component 12.
[0046] General Closing
[0047] The temperature management system 10 removes enough heat to
maintain the thermal component 12 at or below its rated
temperature, which may be; e.g., no more than 125.degree. C. For
example, the temperature management system 10 may maintain the
component 12 at or below 100.degree. C., or even at or below
80.degree. C. Typically, the lower the temperature, the longer the
life of the thermal component 12.
[0048] Thus, the temperature management system 10 may not manage
the temperature of the entire cavity 15 or even the entire
electronics chassis, but does manage the temperature of the thermal
component 12 itself. When absorbing heat from the thermal component
12, the temperature management system 10 may allow the average
temperature of the cavity 15 to reach a higher temperature than
that at which the thermal components 12 are held. Absorbing heat
from the thermal component 12 thus extends the useful life of the
thermal component 12, despite the average temperature of the cavity
15 being higher. This allows the thermal component 12 to operate a
longer duration at a given environment temperature for a given
volume of heat sink than possible if the average temperature of the
entire cavity 15 is managed.
Second Embodiment
[0049] Thermal Component, Heat Exchanger, and Heat Storing
Temperature Management System
[0050] FIG. 4 illustrates a second embodiment of a temperature
management system 310 disposed in a downhole tool 14 such as on a
drill string 16 for drilling a borehole 13 in a formation 17. The
temperature management system 310 might also be used in a downhole
wireline tool, a permanently installed downhole tool, or a
temporary well testing tool. However, the temperature management
system 310 may also be used in other situations and applications
where the surrounding environment ambient temperature is either
greater than or less than that of the thermal components being
cooled.
[0051] As with the temperature management system 10, the
temperature management system 310 manages the temperature of a
thermal component 312 mounted, e.g., on a board 318 in the downhole
tool 14. The temperature management system 310 also comprises a
heat exchanger 320 thermally coupled with the thermal component 312
as with the temperature management system 10. The temperature
management system 310 also comprises a heat storing temperature
management system 311 thermally coupled with the heat exchanger 320
as disclosed in the temperature management system 10, including
similar reference numerals for like parts. The heat storing
temperature management system 311 removes heat from the thermal
component 312 through the heat exchanger 320 and stores the removed
heat within the heat storing temperature management system 311. The
heat storing temperature management system 311 also comprises a
thermal conduit system 326 for thermally coupling the heat
exchanger 320 and the heat sink 322.
[0052] Heat Exhausting Temperature Management System #2
[0053] The temperature management system 310 also comprises a heat
exhausting temperature management system 340. However, in the
temperature management system 310, the heat exhausting temperature
management system 340 is thermally coupled with a second heat
exchanger 321, which is thermally coupled to the thermal component
312 in a similar manner as the heat exchanger 320. Thus, instead of
removing heat from the heat sink 322 of the heat storing
temperature management system 311, the heat exhausting temperature
management system 340 removes heat from the thermal component 312
through the second heat exchanger 321. The heat exhausting
temperature management system 340 then transfers the removed heat
to the environment outside the temperature management system 310.
As before, the heat may be transferred to the drill string 16, the
drilling fluid traveling in the annulus 52 between the downhole
tool 14 and the formation 17, or the drilling fluid being pumped
through the drill string 16 and the downhole tool 14. The heat may
be transferred from the hot plate to the environment directly
through conduction or indirectly through convection or radiation,
or any combination of direct and indirect transfer. The heat
exhausting temperature management system 340 allows removed heat to
be transferred to the drilling fluid even though the drilling fluid
may be at a higher temperature than the thermal component 312. The
heat exhausting temperature management system 340 may also comprise
more than one thermoelectric cooler thermally coupled with the
thermal component 312, thus comprising multiple stages of heat
exhausting temperature management. Instead of a thermoelectric
cooler, alternatively the heat exhausting temperature management
system 340 may comprise a thermoacoustic cooler or a vapor
compression temperature management system. The temperature
management system 310 may also be used to cool more than one
thermal component 312.
[0054] Power for the thermal component 312 and the thermoelectric
cooler 340, is similarly supplied by the turbine alternator 42, a
battery, or combination thereof, which may be driven by the
drilling fluid pumped through the drill string 16. Because the heat
exhausting temperature management system 340 is powered by the
turbine alternator 42, it may only operate during pumping of
drilling fluid through the drill string 16. During that time, the
heat exhausting temperature management system 340 removes heat from
the thermal component 312 and allows the temperature management
system 310 to maintain heat removal from the thermal component 312.
There are, however, periods when drilling fluid is not pumped
through the drill string 16. During these times, the heat
exhausting temperature management system 340 may not be
operational, unless there is some amount of battery power. However,
when the heat exhausting temperature management system 340 is not
operating, the heat storing temperature management system 311 is
still able to remove heat from the thermal component 312 and store
the removed heat the heat sink 322. Once drilling fluid flow is
restored, the heat exhausting temperature management system 340
will then be able to begin removing heat from the thermal component
312. Thus, the heat storing temperature management system 311 and
the heat exhausting temperature management system 340 combine to
manage the temperature of the thermal component 312.
[0055] Alternatively, when the power source 36 is on, the heat
exhausting temperature management system 340 may be operated by a
control system that determines when the heat exhausting temperature
management system 340 operates. The control system is similar to
the control system described above and represented by the flow
chart shown in FIG. 3.
[0056] Thermal Barrier
[0057] The temperature management system 310 may also alternatively
comprise a thermal barrier 350 enclosing the temperature management
system 310. The thermal barrier 350 may also enclose only a portion
of the temperature management system 310. The thermal barrier 350
hinders heat transfer from the outside environment to the
temperature management system 310 and the thermal component
312.
[0058] General Closing
[0059] The temperature management system 310 removes enough heat to
maintain the thermal component 312 at or below its rated
temperature, which may be; e.g., no more than 125.degree. C. For
example, the temperature management system 310 may maintain the
component 312 at or below 100.degree. C., or even at or below
80.degree. C. Typically, the lower the temperature, the longer the
life of the thermal component 312.
[0060] Thus, the temperature management system 310 may not manage
the temperature of the entire cavity 315 or even the entire
electronics chassis, but does manage the temperature of the thermal
component 312 itself. When absorbing heat from the thermal
component 312, the temperature management system 310 may allow the
average temperature of the cavity 315 to reach a higher temperature
than that at which the thermal components 312 are held. Absorbing
heat from the thermal components 312 thus extends the useful life
of the thermal component 312, despite the average temperature of
the cavity 315 being higher. This allows the thermal component 312
to operate a longer duration at a given environment temperature for
a given volume of heat sink than possible if the average
temperature of the entire cavity 315 is managed.
Third Embodiment
[0061] Thermal Component, Heat Exchanger, and Heat Storing
Temperature Management System
[0062] FIG. 5 illustrates a third embodiment of a temperature
management system 410 disposed in a downhole tool 14 such as on a
drill string 16 for drilling a borehole 13 in a formation 17. The
temperature management system 410 might also be used in a downhole
wireline tool, a permanently installed downhole tool, or a
temporary well testing tool. However, the temperature management
system 410 may also be used in other situations and applications
where the surrounding environment ambient temperature is either
greater than or less than that of the thermal components being
cooled.
[0063] As with the temperature management system 10, the
temperature management system 410 manages the temperature of one or
more thermal components 412 mounted on one or more boards 418 in
the downhole tool 14. The temperature management system 410 also
comprises a heat exchanger 420 thermally coupled with the thermal
component 412 as with the temperature management system 10. The
temperature management system 410 also comprises a heat storing
temperature management system 411 thermally coupled with the heat
exchanger 420 as disclosed in the temperature management system 10,
including similar reference numerals for like parts. The heat
storing temperature management system 411 removes heat from the
thermal component 412 through the heat exchanger 420 and stores the
removed heat in within the heat storing temperature management
system 411. The heat storing temperature management system 411 also
comprises a thermal conduit system 426 for thermally coupling the
heat exchanger 420 and the heat sink 422.
[0064] Heat Exhausting Temperature Management System #3
[0065] The temperature management system 410 also comprises a heat
exhausting temperature management system 440. However, in the
temperature management system 410, the heat exhausting temperature
management system 440 is thermally coupled with the heat exchanger
420, not the heat sink 422. Thus, instead of removing heat from the
heat sink 422 of the heat storing temperature management system
411, the heat exhausting temperature management system 440 removes
heat from the heat exchanger 420. The heat exhausting temperature
management system 440 then transfers the removed heat to the
environment outside the temperature management system 410. As
before, the heat may be transferred to the drill string 16, the
drilling fluid traveling in the annulus 52 between the downhole
tool 14 and the formation 17, or the drilling fluid being pumped
through the drill string 16 and the downhole tool 14. The heat may
be transferred from the hot plate to the environment directly
through conduction or indirectly through convection or radiation,
or any combination of direct and indirect transfer. The heat
exhausting temperature management system 440 allows removed heat to
be transferred to the drilling fluid even though the drilling fluid
may be at a higher temperature than the thermal component 412. The
heat exhausting temperature management system 440 may also comprise
more than one thermoelectric cooler thermally coupled with the
thermal component 412, thus comprising multiple stages of heat
exhausting temperature management. Instead of a thermoelectric
cooler, alternatively the heat exhausting temperature management
system 440 may comprise a thermoacoustic cooler or a vapor
compression temperature management system. The temperature
management system 410 may also be used to cool more than one
thermal component 412.
[0066] Power for the thermal component 412 and the thermoelectric
cooler 440 may be similarly supplied by the turbine alternator 42,
which may be driven by the drilling fluid pumped through the drill
string 16. If the heat exhausting temperature management system 440
is powered by the turbine alternator 42, it may only operate during
pumping of drilling fluid through the drill string 16. During that
time, the heat exhausting temperature management system 440 removes
heat from the thermal component 412 through the heat exchanger 420
and allows the temperature management system 410 to maintain heat
removal from the thermal component 412. There are, however, periods
when drilling fluid is not pumped through the drill string 16.
During these times, the heat exhausting temperature management
system 440 may not be operational, unless there is some amount of
battery power. However, when the heat exhausting temperature
management system 440 is not operating, the heat storing
temperature management system 411 is still able to remove heat from
the thermal component 412 and store the removed heat the heat sink
422. Once drilling fluid flow is restored, the heat exhausting
temperature management system 440 will then be able to begin
removing heat from the thermal component 412. Thus, the heat
storing temperature management system 411 and the heat exhausting
temperature management system 440 combine to manage the temperature
of the thermal component 412.
[0067] Alternatively, when the power source 36 is on, the heat
exhausting temperature management system 440 may be operated by a
control system that determines when the heat exhausting temperature
management system 440 operates. The control system is similar to
the control system described above and represented by the flow
chart shown in FIG. 3.
[0068] Thermal Barrier
[0069] The temperature management system 410 may also alternatively
comprise a thermal barrier 450 enclosing the temperature management
system 410. The thermal barrier 450 may also enclose only a portion
of the temperature management system 410. The thermal barrier 450
hinders heat transfer from the outside environment to the
temperature management system 410 and the thermal component
412.
[0070] General Closing
[0071] The temperature management system 410 removes enough heat to
maintain the thermal component 412 at or below its rated
temperature, which may be; e.g., no more than 125.degree. C. For
example, the temperature management system 410 may maintain the
component 412 at or below 100.degree. C., or even at or below
80.degree. C. Typically, the lower the temperature, the longer the
life of the thermal component 412.
[0072] Thus, the temperature management system 410 may not manage
the temperature of the entire cavity 415 or even the entire
electronics chassis, but does manage the temperature of the thermal
component 412 itself. When absorbing heat from the thermal
component 412, the temperature management system 410 may allow the
average temperature of the cavity 415 to reach a higher temperature
than that at which the thermal components 412 are held. Absorbing
heat from the thermal component 412 thus extends the useful life of
the thermal component 412, despite the average temperature of the
cavity 415 being higher. This allows the thermal component 412 to
operate a longer duration at a given environment temperature for a
given volume of heat sink than possible if the average temperature
of the entire cavity 415 is managed.
Fourth Embodiment
[0073] Thermal Component, Heat Exchanger, and Heat Storing
Temperature Management System
[0074] FIG. 6 illustrates a fourth embodiment of a temperature
management system 510 disposed in a downhole tool 14 such as on a
drill string 16 for drilling a borehole 13 in a formation 17. The
temperature management system 510 might also be used in a downhole
wireline tool, a permanently installed downhole tool, or a
temporary well testing tool. However, the temperature management
system 510 may also be used in other situations and applications
where the surrounding environment ambient temperature is either
greater than or less than that of the thermal components being
cooled.
[0075] As with the temperature management system 10, the
temperature management system 510 manages the temperature of one or
more thermal components 512 mounted on one or more boards 518 in
the downhole tool 14. The temperature management system 510 also
comprises a heat exchanger 520 thermally coupled with the thermal
component 512 as with the temperature management system 10. The
temperature management system 510 also comprises a heat storing
temperature management system 511 thermally coupled with the heat
exchanger 520 as disclosed in the temperature management system 10,
including similar reference numerals for like parts. The heat
storing temperature management system 511 removes heat from the
thermal component 512 through the heat exchanger 520 and stores the
removed heat in within the heat storing temperature management
system 511. The heat storing temperature management system 511 also
comprises a thermal conduit system 526 for thermally coupling the
heat exchanger 520 and the heat sink 522.
[0076] Heat Exhausting Temperature Management System #4
[0077] The temperature management system 510 also comprises a heat
exhausting temperature management system 540. However, in the
temperature management system 510, the heat exhausting temperature
management system 540 is thermally coupled with the thermal conduit
system 526, not the heat sink 522. Thus, instead of removing heat
from the heat sink 522 of the heat storing temperature management
system 511, the heat exhausting temperature management system 540
removes heat from the thermal conduit 526. The heat exhausting
temperature management system 540 then transfers the removed heat
to the environment outside the temperature management system 510.
As before, the heat may be transferred to the drill string 16, the
drilling fluid traveling in the annulus 52 between the downhole
tool 14 and the formation 17, or the drilling fluid being pumped
through the drill string 16 and the downhole tool 14. The heat may
be transferred from the hot plate to the environment directly
through conduction or indirectly through convection or radiation,
or any combination of direct and indirect transfer. The heat
exhausting temperature management system 540 allows removed heat to
be transferred to the drilling fluid even though the drilling fluid
may be at a higher temperature than the thermal component 512. The
heat exhausting temperature management system 540 may also comprise
more than one thermoelectric cooler thermally coupled with the
thermal component 512, thus comprising multiple stages of heat
exhausting temperature management. Instead of a thermoelectric
cooler, alternatively the heat exhausting temperature management
system 540 may comprise a thermoacoustic cooler or a vapor
compression temperature management system. The temperature
management system 510 may also be used to cool more than one
thermal component 512.
[0078] Power for the thermal component 512 and the thermoelectric
cooler 540, may similarly be supplied by the turbine alternator 42,
which may be driven by the drilling fluid pumped through the drill
string 16. Because the heat exhausting temperature management
system 540 is powered by the turbine alternator 42, it may only
operate during pumping of drilling fluid through the drill string
16. During that time, the heat exhausting temperature management
system 540 removes heat from the thermal component 512 through the
thermal conduit 526 and allows the temperature management system
510 to maintain heat removal from the thermal component 512. There
are, however, periods when drilling fluid is not pumped through the
drill string 16. During these times, the heat exhausting
temperature management system 540 may not be operational, unless
there is some amount of battery power. However, when the heat
exhausting temperature management system 540 is not operating, the
heat storing temperature management system 511 is still able to
remove heat from the thermal component 512 and store the removed
heat the heat sink 522. Once drilling fluid flow is restored, the
heat exhausting temperature management system 540 will then be able
to begin removing heat from the thermal component 512. Thus, the
heat storing temperature management system 511 and the heat
exhausting temperature management system 540 combine to manage the
temperature of the thermal component 512.
[0079] Alternatively, when the power source 36 is on, the heat
exhausting temperature management system 540 may be operated by a
control system that determines when the heat exhausting temperature
management system 540 operates. The control system is similar to
the control system described above and represented by the flow
chart shown in FIG. 3.
[0080] Thermal Barrier
[0081] The temperature management system 510 may also alternatively
comprise a thermal barrier 550 enclosing the temperature management
system 510. The thermal barrier 550 may also enclose only a portion
of the temperature management system 510. The thermal barrier 550
hinders heat transfer from the outside environment to the
temperature management system 510 and the thermal component
512.
[0082] General Closing
[0083] The temperature management system 510 removes enough heat to
maintain the thermal component 512 at or below its rated
temperature, which may be; e.g., no more than 125.degree. C. For
example, the temperature management system 510 may maintain the
component 512 at or below 100.degree. C., or even at or below
80.degree. C. Typically, the lower the temperature, the longer the
life of the thermal component 512.
[0084] Thus, the temperature management system 510 may not manage
the temperature of the entire cavity 515 or even the entire
electronics chassis, but does manage the temperature of the thermal
component 512 itself. When absorbing heat from the thermal
component 512, the temperature management system 510 may allow the
average temperature of the cavity 515 to reach a higher temperature
than that at which the thermal components 512 are held. Absorbing
heat from the thermal component 512 thus extends the useful life of
the thermal component 512, despite the average temperature of the
cavity 515 being higher. This allows the thermal component 512 to
operate a longer duration at a given environment temperature for a
given volume of heat sink than possible if the average temperature
of the entire cavity 515 is managed.
[0085] While specific embodiments have been shown and described,
modifications can be made by one skilled in the art without
departing from the spirit or teaching of this invention. The
embodiments as described are exemplary only and are not limiting.
Many variations and modifications are possible and are within the
scope of the invention. Accordingly, the scope of protection is not
limited to the embodiments described, but is only limited by the
claims that follow, the scope of which shall include all
equivalents of the subject matter of the claims.
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