The performance of many electrical components (e.g., electrical components on-board
an aircraft) is dependent upon the temperature at which the electrical component operates.
Specifically, many electrical components generate heat during operation. The heat can
build up to an extent that the operating temperature of an electrical component negatively
affects thc performance of the clectrical component. For cxarnple, the speed at which a
processor processes signals may be reduced when the processor operates at higher
operating tcmperatures. Moreover, and for example, the efficiency of an electrical power
coniponcnt that supplics clcctrical powcr may bc reduced whcn thc clcctrical powcr
component operates at higher operating temperatures. Higher operating temperatures may
also decrease the operational life of an electrical component. Accordingly, it may be
dcsirable to cool an clectrical component t during operation thereof to maintain the
operating temperature of the electrical component below a predetermined threshold.
RRlEF DESCRIPTION
In one embodiment, a cooling system is provided for cooling an clcctrical
component. The cooling system includes a supply of liquid natural gas (LNG) and a heat
sink configured to be positioned in thermal communication with the electrical component.
The cooling system also includes an LNG conduit configured to be interconnected between
the heat sink and the supply of LNG such that the LNG conduit is configured to carry LNG
from thc supply to the heat sink A pump i~ configured to be operatively connectcd in
fluid communication with the supply of LNG. The pump is contlgurcd to move LNG within
the LNG conduit from the supply to the hcat sink
[0003] In another crnbodiment, a method is provided for cooling an clcctrical component.
The method includes supplying a flow of liquid natural gas (LNG) from
a supply of the LNG to a heat sink that is positioned in themlal, communication with the
electrical component. The method also includes dissipating heat from t h e
clcctrical component by absorbing heat from the heat sink using the LNG.
In another embodiment, an aircraft includcs an airframe, an electrical componcnt onboard
the airframe, and a cooling system on-board the airframe. The cooling system
includcs a supply of liquid natural gas (LNG), a hcat sink positioned in thermal
communication with the electrical component, and an LNG conduit interconnected between
the heat sink and the supply of LNG such that the LNG conduit IS configured to carry
LNG from the supply to the heat sink. A pump is operatively connected in fluid
communication with the supply of LNG. The pump is configured to move LNG within the
LNG conduit from the supply to thc heat sink.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is schematic illustration of an embodiment of a cooling system for
cooling an electrical component.
Figurc 2 is a schematic illustration of an embodiment of an aircraft.
Figure 3 is a flowchart illustrating an embodiment of a method for cooling an
electrical component.
Figurc 4 is a perspective vicw of an embodiment of a hcat sink. [0009] Figure 5 is a
perspective vicw of another embodiment of a heat sink.
Figure 6 is a cross sectional view of a portion of an embodiment of a liquid naturaE
gas (LNG) conduit.
DETAILED DESCRIPTION
The following detailed description of certain embodiments wW be better
understood when read in conjunction with the appended drawings. It should be
Understood that the various embodiments are not 1 i mi t e d to the arrangements and
instrumentality shown in the drawings.
As used herein, an element or step recited in the singular and proceeded
w~tli thc wod "aff or "an1' should be understood as not excluding plural of said
clements or steps, unless such exclusion is explicitly stated. Furthermore,
references to "one enlbodiment" are not intended to be interpretted as excluding the
cxlstcnce of additional embodiments that also incorporate the reeitcd features.
Moreover, unless explicitly stated to the contrary, embodiments "comprising" or
"having" an element or a plurality of elements having a particular property may
include additional such elements not having that property.
Various embodiments of systems and methods are provided for cooling electrical
components using liquid natural gas (LNG). At least one technical effect of various
embodiments is an electrical component having an incrcased operational life span
andor increased performance (such as, but not limited to, higher speed, greater
efficiency, and/or the like). For example, at least one technical effect of various
embodiments may bc a processor that processes signals at higher speeds. Moreover, and
for example, at least one technical effect of various embodiments may be an
clcctrical power component that opera tes at a greater efficitmcy. At least one other
technical effect of various embodimcnts is the ability to cool electrical components
using LNG that is contained on-board an aircraft for use as fuel for an engine of the
aircraft.
The vanous embodimcnts of cooling systems and methods are described
and illustrated herein with respect to being used for cooling electrical components
on-board an aircraft. But, the various embodiment.; of cooling systems and methods
are not limited to being used with aircraft. Rather, the vanous
embodiments of cooling systems and methods may be used to cool any type of
clcctrical component that is locatcd on any stationary andlor mobile platform, such as,
but not limitcd to, trains, automobiles, watercraft (e.g., a ship, a boat, a maritime
vessel, andlor the like), andlor the like. Additional1 y, the various embodiments of
cooling systems and methods are described and illustrated herein with respect to a
fixed wing airplanc. But, the various cmbodimcnts of cooling systems and methods are
not limited to airplanes or fixed wing aircraft. Rather, the various embodiments of cooling
systems and methods may be implemented within other types of aircraft having any
other design, structure, configuration, arrangement, andlor the like, such as, but not
limited to, aerostats, powered lift aircraft, andlor rotorcraft, among others.
Figure 1 is schematic illustration of an embodiment of a cooling system
10. The cooling system 10 is used to cool onc or more clcctrical componcnts
12 using LNG. LNG has a temperature of approximately 11 1 K and may be
considered cryogenic. Accordingly, LNG may be a suitable cooling medium for
clcctrical componcnts 12 that operate at tcmperaturcs above approximately 11 1 K.
The cooling system 10 may be used to cool any number of electrical components 12.
For clarity, the cooling system 10 will be described and illustrated with reference to
Figure 1 as cooling a singlc clectrical component 12. Each clcctrical component 12
may be any type and quantity of electrical component, such as, but not limited to,
signal processor, power distribution component, power source, capacitor, an electrical
componcnt that proccsscs, transmits, or relays data, and/or thc like.
The cooling system 10 in this embodiment includes a supply 14 of LNG, a
heat sink 16, an LNG conduit system 18, and a pump 20. The supply 14 is configured
to hold a supply of LNG and may be thennally insulated andlor provided with a cooling
system (not shown) to enable the supply to store the natural gas jn the liquid state. As
will bc described below, thc supply 14 may be a fucl tank of an aircraft (e.g., the
fuel tank 126 of the aircraft 100 shown in Figure 2) such that the cooling system 10
shares the same supply and may share some of the piping, pumps, controller
functionality, and/or the like.
The heat sink 16 in this example is positioned in themlal communication
with the electrical component 12. For example, the heat sink 16 may engage the
clcctrical component 12 and/or the hcat sink 16 may cngagc a thermal interface
material (TIM, not shown) that is engagcd with the clectrical component 12.
In the illustrated embodiment, the heat sink 16 is positioned in thermal
communication with a single electrical component 12. But, the heat sink 16 may be
positioncd in thermal communication with any number of electrical components 12. In
one example, the heat sink 16 can be deployed on more tihan one side of the
clectrical component 12. The heat sink 16 may include one or more cooling fins (not
shown). In somc cmbodimcnts, the heat sink 16 is a fluid block.
The LNG conduit system 18 is fluidly interconnected between the supply 14
and the heat sink 16 for carrying LNG from the supply 14 to the heat sink
16. In the illustrated mbodiment, the LNG conduit systcm 18 includes LNG
conduits 22 and 24. Each of the LNG conduits 22 and 24 is fluidly interconnected
bctwctm the suppl y 14 and the heat sink 16. In other words, each of the LNG
conduits 22 and 24 provides a fluid path betwccn the supply 14 and the heat sink 16.
The LNG conduit 22 and/or the LNG conduit 24 may be thermally insulated along at
least a portion of the length thereof to facilitate maintaining the LNG below a
predetcrmincd tcmpcraturc. For cxarnple, the LNG conduit 22 and/or the LNG
conduit 24 may be thennally insulated to facilitate maintaining the LNG in the liquid
state. Any type of thermal insulation may be used, such as, but not limited to, pipe
insulation, mineral wool, glass wool, an elastomcric foam, a rigid foam, polyethylcnc,
aerogel, a double-walled conduit (e.g., with a vacuum between tihe walls), and/or the
lib. Thc thermal insulation may bc applied to the LNG conduit 22 andlor 24 in any
manner, such as, but not limited to, extending around the LNG conduit 22 andor 24,
being wrapped around the LNG conduit 22 andlor 24, and/or the like.
The LNG conduit 22 is a supply conduit that is configured to carry LNG from
the supply 14 to the heat sink 16. In the illustrated embodiment, the LNG conduit 24 is a
return conduit that is configured to carry, or return, LNG from the heat sink 16 to the
supply 14. Accordingly, in the illustratcd embodiment, the LNG is rcturncd to thc
supply 14 after being used to cool the clectrical component 12. In other words, the
LNG conduit system 18 is a closed loop system in the illustrated embodiment. In
other embodiments, the LNG conduit system 18 is an open loop systcm wherein the
LNG is not returned to the supply 14 after being used to cool the
electrical component 12. Rather, in such other embodiments, after being used to cool the
electrical component 12 the LNG is carried to another component, such as, but not limited
to, a waste or other type of collection container (not sihown), an enginc, a furnace,
and/or the like. For example, after being used to cool the electrical component
12, there may be a complete or partial vaporization of the LNG, and such vapor may be
supplied to an engine for use as fuel by the engine, may be disposed of as waste, andlor
may be reliquified and returned to the supply 14.
In Figure 1, the LNG conduit system 18 is illustrated as a relatively simple
system for fluidly interconnecting a single heat sink 16 to the supply 12 of LNG.
But, one or more other heat sinks 16 may be fluidly interconnected to the supply 14
by the LNG conduit system 18. The LNG conduit systcm 18 may thus be used to
supply LNG to a plurality of heat sinks 16. Each of such other heat sinks 16 may be
positioned in thermal communication with any number of electrical components
12. Moreover, each of such other hcat sinks 16 may be fluidly interconnected
in serles or parallel with the heat sink 16 shown in Figure 1. Accordingly, such
other heat slnks 16 may include one or more heat sinks 16 that is fluidly interconnected
to thc supply 14 of LNG in serics with the hcat sink 16 shown in Figure 1 andlor one
or more heat sinks 16 that is fluidly interconnected tto the supply 14 of LNG in
parallel with the heat sink 16 shown in Figure 1. The LNG conduit system 18 may
include any number of LNG conduits, which may be arrangcd in any pattern, paths,
andor the like, for fluidly interconnecting any number of heat sinks 16 to the supply 14
of LNG.
The pump 20 is operatively connected in fluid communication with thc supply 14.
Operation of the pump 20 moves LNG within the LNG conduit system 18. For example,
the pump 20 moves LNG within the LNG conduit 22 from the supply 14 to the heat sink
16. In the illustrated embodiment, the pump 20 also moves LNG within the LNG
conduit 24 from the heat sink 16 to the supply 14. In other embodiments
wherein the LNG is not rcturned to the supply 14 after being used to cool the electrical
component 12, the pump 20 may move the LNG within the LNG e0ndui.t 24 from the
hcat sink 16 to another component as described above. Although
only a single pump 20 is shown, the cooling system 10 may include any number of
pumps 20. Each pump 20 may have any location within the cooling system 10 that
cnablcs the pump 20 to move LNG within the LNG conduit systcm 18. For example, thc
illustrated cnibodiment of the pump 20 is located along the LNG conduit 22. But, other
cxcmplary locations of the pump 20 include a location along the LNG conduit
24, a location within thc supply 14, and/or thc likc. Each pump 20 may be any type of
pump that enables the pump 20 to move LNG within the LNG conduit systcm 18,
such as, but not limited to, a positive displacement pump, an impulse pump, a
hydraulic ram pump, a vclocity pump, a centrifugal pump, an educator-jet pump, a
gravity pump, a valve less pump, andor the like. In some embodiments, the pump 20 is a
fucl pump for an engine. In some embodiments, the pump 20 may bc located such
that the pump 20 does not directly contact the LNG but operates at ambient temperatures,
such as, but not limited to, by pressurizing the supply 14 of LNG. Such
a location of the pump 20 may be easier andlor less costly to implement.
The cooling system 10 may include a controllcr 26 or other sub-systcm for
controlling operation of the cooling system 10. For example, the controlner 26 may
control activation and deactivation of operation of the cooling system 10.
Morcovcr, and for examplc, thc controllcr 26 may control operation of the pump 20,
any valves (not shown) of the cooling system 10, and/or any other components of the
cooling systcm 10. The controller 26 may control various operations of the pump 20,
such as, activation and deactivation of the pump 20, a flow rate of the LNG provided by
the pump 20, and/or the like. Other exemplary operations of the controlEer 26
includc, but arc not limited to, monitoring one or more sensors (not shown) that
determine operating andlor other temperatures of the electrical component 12,
controlling valves to control the flow of LNG to different heat sinks 16 of the cooling
systcm 10, andlor thc likc. Othcr scnsors may bc intcgratcd into the systcm 10 to
rnon~tor LNG pressure, LNG temperature, LNG veloci ty, and/or the like within the
LNG conduit system 18. Moreover, in an aircraft application, other sensors may be
used to maintain thc integrity and safety of the aircraft, which may includc cfficicncy of
operations that may use the LNG supply up to a margin required for cooling.
Operation of the cooling system 10 to cool the electrical component 12 will now
be described. The electrical component 12 generates heat during operation thercof.
Thc thermal communication bctween the hcat sink 16 and thc clcctrical conlponent
12 enables the heat sink 16 to absorb at least some of the heat generated by the
electrical component 12. A flow of the LNG is supplied from the supply 14 to the heat
sink 16. The flow of LNG is supplied to the hcat sink 16 such that the LNG flows along
andor within the heat sink 16 in thermal communication therewith. In one example,
thc hcat sink 16 includcs one or more channels that provide for fluid communication
of' the LNG. The thermal communication between the LNG flow and the heat sink 16
enables the LNG to absorb at least some heat from the heat sink 16. The LNG thus
dissipatcs at lcast some heat from thc clcctrical componcnt 12 through thc hcat sink 16.
In some embodiments, the LNG absorbs enough heat fkom the heat sink 16 such that the
LNG changes to a gaseous state and/or vaporizes.
Thc cooling system 10 may be used to dissipate any amount of heat from the
clcctrical component 12. For example, the cooling system 10 may cool the electrical
component 12 to any operating temperature or range thereof. Examples of operating
tcmpcraturcs or rangcs thereof to which the cooling system 10 may cool thc clcctrical
component include, but are not limited to, an operating temperature of below
approximately 300 K, an operating temperature of below approximately 250 K, an
opcrating temperature of bclow approximately 160 K, an operating temperature of
between approximately 130 K and 170 K, an operating temperature of between
approximately 140 K and 160 K, andor the like. Such operating temperatures may be
achicvcd by ]balancing thc LNG flow along and/or through the heat sink 16 with the
ratc of heat generation by certain components 12.
Various parameters of the various componen ts of the cooling systcm
10 may be sclccted to adapt the functionality of the systcm 10 to a specific
application, to provide the system 10 with a predetermined functionality (e.g., a
cooling capability of the system 10, the number of electrical compontmts 12 that thc
systcm 10 is used to cool, thc cfficicncy of the systcm 10, the type(s) of clcctrical
components 52 that the system 10 is used to cool, and/or the like), andor the like.
Examples of such various parameters include, but are not limited to, the dimensions andlor
materials of the heat sink 16, the dimensions of the various conduits of the LNG conduit
system 18, the pressure(s) within the LNG conduit system 18, the volume and/or
velocity of flow within the LNG conduit system 18, the amount of LNG contained within
thc cooling system 10, the use ofvarious conduit features (e.g., valves, restrictors, blowouts,
manual shutoffs, automatic shutoffs, and/or the like), and/or the like.
The heat sink 16 may be configured to be in thermal communication with the LNG
flow received from the supply 14 using any arrangement, means, structure,
configuration, and/or the like. For example, the flow of LNG may engage the heat sink 16
to establish the thermal communication therebetween. Moreover, and for example, the LNG
flow may thcrrnally communicate with the heat sink 16 through one or more intervening
structures (e.g., a conduit wall, a TIM, andlor the like) that is engaged between the LNG
flow and the heat sink 16. Exemplary configurations for establishing the thermal
communication between the LNG and the heat sink 16 will be described below with
reference to Figures 4 and 5.
The cooli ng system 10 may be used to cool electrical components that are located
on-board an aircraft. For example, Figun: 2 is a schematic illustration of an embodiment of
an aircraft 100 that includes a cooling system 110 that uses LNG in a substan tially similar
manner to the cooling system 10 (Figure 1). In the illustrated embodment, the aircraft 100
is a fixed wing passenger airplane. ?he aircraft 100 includes a plurality of electrical
components 1 12, an airframe 1 14, a source 1 16 of electrical power, a power distribution
system 118, an engine system 120, and the cooling system 110. The source 116, the
electrical components 1 12, the powcr distribution system 1 18, the engine system 120, and
the cooling system 1 10 are each located on-board the airframe 1 14. Specifically, the source
1 16, the electrical components 1 12, the power distribution system 1 18, the engine system
120, and the cooling systcm 110 are positioned at various locations on andlor within the
airframe
114 such that the source 11 6, the electrical components 1 12, the power distribution
system 118, the engine system 120, and the cooling system 110 are carried by the
airframe 1 14 during flight of the aircraft 100.
The power distribution system 118 is configured (e.g., operatively connected)
between the sourcc 116 and the electrical components 112 to carry electrical power
from the source 1 16 to the electrical components 112. The source
116 may be any typc of source of electrical power, for example a gcneration dcvicc or a
storage device. In the illustrated embodiment, the aircraft 100 includes two sources
116 that are each turbine generators associated with the engine system 120 of the aircraft
100. Other cxamplcs of the source 116 as a gcneration dcvice include elcctrical
generators and/or solar cells, among others. Examples of the source 116 as a storage device
include fuel cells, batteries, flywheels, andlor capacitors, among others. Although shown
as being located at thc cnginc system 120 of the aircraft 100, each source 1 16 may be
located at any other location along the airframe 114. Moreover, although two are
shown, the aircraft 100 may include any number of the sources 116.
Sub-sets 122 of the electrical components 112 arc shown in Figure 2 at various
locations along the airframe 114. Each sub-set 122 may include any number of electrical
components 1 12. In some embodiments, one or more sub-sets 122 only includes a single
electrical component 112. When a sub-set 122 includcs two or more electrical components
112, all of the electrical components 112 of the sub-set 122 may be of the same type or the
sub-set 122 may include two or more different types of electrical components 1 12. The
aircraft 100 may include any number of the sub-sets
122. In some embodiments, it may be advantageous to arrange the sub-sets 122 such that
electrical components 112 that benefit from cooling using the LNG are grouped together.
Such sub-sets J 22 may be coolcd using LNG as dcscribcd and/or illustratcd herein, while
sub-sets 122 that do not benefit from cooling using LNG are left uncooled andlor are
cooled by othcr means.
Thc locations and pattern of sub-sets 122 along thc airframc J 14 shown in
Figure 2 are for example only. Each sub-set 122 may have any other
lowt~on along the airframe 114 and the sub-sets 122 may be arranged in any other pattern
relative to each other. Moreover, the electrical components 112 of the same sub-set 122 are
shown in Figure 1 as grouped together at the samc location along the airframe 114 for
illustrative purposes only. The electrical components 112 of the same subset 122 need
not be located at the same location along the airframe 114. Rather, each electrical
component 112 may have any location along the airframe 114, whether or not such location
is the same, or adjacent to, the location of one or more other electrical components 112 of
thc samc sub-set 122. In some cmbodiments, the clectrical components are groupcd
together in the sub-sets 122 based on corresponding power distribution modules (not
shown) of the power distribution system 118 that are common to groups (i.e., the sub-sets
122) of the clectrical components 1 12.
Each electrical component 112 of each sub-set 122 may be any type of electrical
component. Examples of the electrical components 112 include flight controls,
avionics, displays, instruments, sensors, galley ovens, heaters, refrigeration units, lighting,
fans, de-ice and anti-ice systems, engine management systems, flight management systems,
power distribution componen ts, starters, starter-generators, environmental controls,
pressurization systcms, entertainment systems, microwaves, weapon systcms, and'or cameras,
among others.
The engine system 120 includes one or more engines 124 and one or more fuel
tanks 126. The fucl tank 126 contains a supply of fuel. Each of thc cngines
124 is opwatively connected in fluid communication to receive fuel from one or more of the
fuel tanks 126. The cngines 124 use the fuel supplied from the fuel tanks 126 to generate
thrust for gcncrating and controlling flight of the aircraft 100. Thc engine system J 20 may
include one or more fuel pumps 128. Each fuel pump 128 is operatively connected in
fluid communication with one or more corresponding fuel tanks 126 and with one or more
corresponding engines 124 for pumping he1 from the fucl tank(s) 126 to the cngine(s) 124.
The aircraft 100 may include any number of fuel tanks 126, each of which may
have any location along the airframe 114. In the illustrated embodiment, the aircraft 100
includcs a single he1 tank 126 that is located within a fuselage 130 of the airframe 114.
Examples of other locations of fuel tanks 126 include, but are not limited to, fuel tanks
(not shown) located within corresponding wings 132 of thc airframe 1 14. The aircraft
100 may include any number of fuel pumps 128. Each fuel pump 128 may have any
location along the airframe 114. In the illustrated embodiment, the fuel pumps 128 are
located within the fuel tank 126. Examples of othcr locations of hcl pumps include,
but are not limited to, mounted to a corresponding engine 124, located proximate a
corresponding engine 124, andor the like.
Each engine 124 may be any type of engine, such as, but not limitcd to, a turbine
engine, an engine that drives a propeller or other rotor, a radial engine, a piston engine, a
turboprop cngine, a turbofan cngine, andlor the like. Although two are shown, tlhe aircraft
100 may include any number of the engines 124. Although shown located on the wings
132 of the airframe 1 14, each engine 124 may have any other location along the airframe
1 14. For cxamplc, the aircraft 100 may include an engine 124 located at a tail 134 and/or
another location along the fuselage 130 of the airframe 114.
Each engine 124 may use any type(s) of fuel, such as, but not limited to, a
petrolcum-based fucl, hydrogen, natural gas. andlor the like. In the exemplary embodiment,
the engines 124 are configured to use at least natural gas as fuel. The fuel tank 126 is
configured to hold a supply of LNG. The fuel tank 126 may be thermally insulated
and/or provided with a cooling system (not shown) to enable the fuel tank 126 to store thc
natural gas in the liquid state. The engines 124 use the natural gas as fuel in the gaseous
statc. The cnginc system 120 may include one or more heating systems 136 that heat the
LNG stored by the fucl tank 126 to change thc LNG stored by thc fucl tank 126 to the
gaseous state for supply to the engines 124 as fuel.
In some other embodiments, one or more of the engines 124 is configured to
use both natural gas and onc or more other types of fuel, whether at thc same andlor different
times. Morcovcr, in some other embodiments, one or more of the engines 124 is not
configured to use natural gas as a fuel. Accordingly, it should be understood that the aircraft
100 may includc a fucl tank (not shown) that holds a diffcrcnt type of fuel than natural gas.
It should also be understood that the aircraft
100 may include one or more other supplies of LNG that is not a fuel tank for an engine
124. In othcr words, the aircraft 100 may include one or more supplies of LNG that is
not a component of the engine system 120.
The cooling system 110 includes a supply of LNG. In the illustrated embodiment,
the LNG supply of the cooling system 110 is the fuel tank 126. In other embodiments, the
cooling system 110 includcs a supply of LNG that is separate from the fuel tank 126 (c-g., a
supply that is not a fuel tank). Moreover, in some embodiments, a backup supply of LNG
is provided for supplying the cooling system
1 10 with LNG when the supply of LNG from a main supply (c.g., the fuel tank I26 in
the illustrated embodiment) is interrupted. In the illustrated embodiment, the cooling system
1 10 includes two cooling circuits 1 1 Oa and 1 lob. The cooling circuit 1 1 Oa is used to cool
sub-groups 122a and 122b of the clectrical components 1 12, while thc cooling circuit 1 lob
cools the sub-groups 122c and 122d of the electrical components
112. The cooling system 110 may include any number of cooling circuits. Each cooling
circuit may cool any number of electrical components 112 and any number of sub-groups
The cooling circuit llOa includes one or more heat sinks 2 16a, an LNG conduit
system 218a, and a pump. Similarly, the cooling circuit 1 lob includes one or more heat
sinks 2 16b, an LNG conduit system 21 8b, and a pump. In the illustrated embodiment,
the pumps of the cooling circuits UOa and llOb are corresponding fuel pumps 128 of the
cnginc systcm 120. In other cmbodimcnts, the cooling circUJit 1 lOa andlor the cooling
circuit llOb includcs a pump that is separate from the corresponding fuel pump 128 of the
cngine system 120.
Referring now to the cooling circuit 110a, thc LNG conduit system
218a is fluidly interconnected between the fuel tank 126 and the heat sinks 216a of the
sub-groups 122a and 122b for carrying LNG from the fuel tank 126 to the heat sinks
2 16a. In thc illustrated embodiment, thc heat sinks 216a are fluidly
intcrconnected with the LNG conduit system 2 18a in parallel with each other. During
operation of the cooling circuit 110a, the LNG flow absorbs at least some heat from the heat
sinks 216a such that the LNG dissipates at least somc hcat from the sub- groups 122a and
122b of the electrical components 112. In some embodiments, the LNG absorbs enough
heat from the heat sinks 2 16a such that the LNG changes to a gaseous state andfor
vaporizes.
Thc LNG conduit system 2 18b of the cooling circuit llOb is fluidly interconnected
between the fuel tank 126 and the heat sinks 216b of the sub-groups
122c and 122d for carrying LNG from the fuel tank 126 to the heat sinks 216b. In the
illustrated embodiment, the heat sinks 216b are fluidly interconnected with the LNG conduit
systcrn 218a in scrics with cach other. During operation of the cooling circuit 110b, the LNG
flow absorbs at least some heat from the heat sinks 216b such that the LNG dissipates at
least some heat from the sub-groups 122c and 122d of the electrical components 112. In
some cmbodimcnts, the LNG absorbs enough heat from the heat sinks 216b such that the
LNG changes to a gaseous state andlor vaporizes.
In the illustrated embodiment, the LNG conduit systems 218a and
2 18b arc cach open loop systems wherein the LNG used to cool thc sub-groups 122a,
122b, 122c, and 122d, respectively, is then delivered to the engines 124 for use as fuel by the
engines 124. Alternatively, the LNG conduit system 2 18a and/or 21 8b is a closed-loop
systcrn whcrcin the LNG is returned to the fuel tank 126 aftcr bcing uscd to cool the
respcctive sub-groups 122a, 122b, 122c, and 122d. In another example, the closed loop
system can provide some portion of the LNG to the engines 124 and some portion back to
thc fucl tank 126.
As described above, the engines 124 use natural gas as fuel nn the gaseous state.
The heat absorbed by the flow of LNG increases the temperature of the
LNG. The incrcasc in temperature of the LNG aftcr cooling the clcctrical components
112 may facilitatc supplying the LNG to thc engines 124 in a gascous statc. For
example, the heat absorbed by the flow of LNG may increase the temperature of the LNG
toward a supply temperature at which the LNG is supplied to the cngines I24 in a gaseous
statc. The increase in temperature of the LNG via the heat sinks 216 may replace the
heating system 136 or may supplement the heating system 136. For example, in some
cmbodimcnts, the heat absorbed by the LNG from the heat sinks
216 is sufficient to raisc the temperature of the LNG to thc supply temperature,
wherein the aircraft 100 may or may not include the heating system(s) 136. In other
embodiments, the heat absorbed by the LNG from the heat sinks 216 may not be sufficient to
raisc thc tcmpcraturc of the LNG to the supply tempcrature. In such embodiments, the
LNG is further heated by the heating system 136 to raise the temperature of the LNG to the
supply temperature (whether it is the heat absorbed by the heat sinks or the heat applied by
the heating system 136 that vaporizes andlor changes the LNG to a gaseous state).
Various tempcrature sensors can be deployed throughout the cooling system 110 to monitor
thc tcmpcraturc and dctcnnine whethcr the heating system 136 is rcquired to raise thc LNG
tclnperature.
Figure 3 is a flowchart illustrating an embodiment of a method 300 for cooling an
clcctrical component. For example, the method 300 may be prcfonned using the cooling
system 10 (Figure 1) or the cooling system 110 (Figure 2). The method 300 includes, at
302, supplying a flow of LNG from a supply of the LNG to a heat sink that is positioned in
thcrmal communication with thc clcctrical component.
13. In some embodiments, supplying at 302 the LNG flow to the heat sink includes
supplying, at 302a, the flow of LNG from a fuel tank (e.g., the fuel tank 126 shown in Figure
1) of an aircraft cnginc.
At 304, the method 300 includes dissipating heat from the electrical component by
absorbing heat from the heat sink using the LNG. Any amount of heat may be dissipated at
304 from the clcctrical component. For example, the electrical componcnt may be cooled to
a desired operating temperature or range of the electrical component. In some embodiments,
the LNG absorbs enough heat from the heat sink such that the LNG changes to a gaseous
statc andlor vaporizes. For example, thc step 304 of dissipating heat from thc clcctrical
component may include, at 304a, at least partially vaporizing the LNG. The vaporized LNG
can be vaporized directly from the interaction with the heat sink andlor via a hcating system
such that thc vaporized LNG is used as fuel for an cnginc. In one cxamplc, at least some of
the LNG is returned to the supply. In some embodiments, dissipating at 304 includes
incrcasing the temperature of the LNG toward a supply tempcrature at which the LNG is
supplied to an engine in a gaseous state for use by the engine as hel.
Figurc 4 is a perspective vicw of an cmbodimcnt of a hcat sink 3 16 that may bc uscd
with the cooling system 10 (Figure 1) and/or the cooling system 110 (Figure 2). 'fhe heat
sink 3 16 is a fluid block that includes one or more passageways
318 that rcccivcs a flow ofLNG from an LNG conduit system (c.g., thc LNG conduit system
18 shown in Figure 1, the LNG conduit system 2 18a shown in Figure 2, andlor the LNG
conduit system 2 18b shown in Figure 2). Although shown with the shape of a parallelepiped,
thc hcat sink 316 may additionally or alternatively include any othcr shape.
In the illustrated embodiment, the heat sink 3 16 includes a single passageway 3 18
that extends along a path within the heat sink 316 that inciU!des a plurality of loops 320.
But, the hcat sink 316 may includc any number of the passageways 318, which may each
follow any path through the heat sink 3 16. When a plurality of passageways 318 are
providcd, the passagcways 3 18 may be arranged in any pattern rclative to each other, which
may include passageways 318 arranged in series with each other, passageways 3 18
arranged in parallel with each other, or a combination thereof. In some embodiments, two
or morc passagcways 3 18 arranged in parallel with cach othcr may be interconncctcd by an
intervening passageway (not shown). The passageways 3 18 may be arranged in any pattern
relative to each other. The number, pattern, path, size, and/or the like of the
passagcways 3 18 may be sclcctcd to provide a predctcrmincd amount of surfacc arca
for thermal colmunication with the LNG. Although shown as having a cylindrical shape,
each passageway 3 18 may additionally or alternatively include any other shape and may
include turbulators of any type.
In the illustrated embodiment, the passageway 3 18 includes an interior surface 322 of
the heat sink 3 16 that engages the LNG as the LNG flows through the passageway 3 18. The
engagement bctwecn the LNG and the interior surfacc 322 cstablishcs tlhe thcnnal
communication between the LNG and the heat sink 3 16. Alternatively, the passageway
3 18 receives an LNG conduit (e.g., the LNG conduit 22 and/or the LNG conduit 24
shown in Figurc 1) of the LNG conduit systcm therethrough. Specifically, a wall of
the LNG conduit may be engaged with the interior surface 322 of the passageway 3 18 to
establish thc thermal communication betwccn the LNG and thc hcat sink 31 6. For example,
the LNG conduit may include an insulated segment and an uninsulated segment. The
~nsulatcd segment may extend a length from the supply of LNG to the heat sink 3 16 (or vice
vcrsa) and is thermally insulated along at lcast a portion of the length thcrcof. The
uninsulated segment extends from the insulated segment through the passageway 3 18. A
wall of the uninsulated segment engages the interior surface 322 of the passageway
3 18 to establish the thermal communication between the LNG and the heat sink 3 16.
Figure 5 is a perspective view of another embodjment of a hcat sink
41 6 that may be used with the cooling system 10 (Figure 1) and/or the cooling system
110 (Figure 2). The heat sink 416 includes an exterior surface 422 that engages an
LNG conduit (c.g., the LNG conduit 22 and/or the LNG conduit 24 shown in Figure
1) of an LNG conduit systcm to establish the thermal communication between the LNG
and the heat sink 416. Although shown with the shape of a parallelepiped, the heat sink 41 6
may additionally or alternatively include any other shape.
The LNG thermally communicates with the heat sink 416 through an intervening
structure that is engaged between the LNG and the heat sink 416. Specifically, a wall of the
LNG conduit engages the exterior surface 422 of the heat sink 416 to establish the thennal
communication between the LNG and the heat sink
416. The exterior surface 422 may be approximately flat. Alternatively, and as
shown in the illustrated embodiment, the exterior surface 422 includes one or more
passageways 418 formed thcrcin. The passagcway(s) 418 receives the LNG conduit (e.g.,
the LNG conduit 22 andlor the LNG conduit 24 shown in Figure 1) of the LNG c0ndui.t
system therein. For example, the LNG conduit may include an insulated segment and
an uninsulated segment. The insulated segment may extend a length from the supply of
LNG to the heat sink 416 (or vice versa) and is thermally insulated along at least a portion of
the lcngth thereof. The uninsulated segment extends from the insulated segment within the
passageway(s) 4 18.
In the illustrated embodiment, the heat sink 416 includes a single passageway 418
that cxtcnds along a path along the extcrior surface 422 that includes a plurality of loops
420. But, the heat sink 416 may include any number of the passageways 418, which
may each follow any path along the exterior surface 422. When a plurality of passageways
41 8 are provided, the passageways 418 may bc arranged in any pattern relative to each
othcr, which may includc passageways 418 arranged in series with each other,
passageways 418 arranged in parallel with each other, or a combination thereof. In some
embodiments, two or more passageways 418 arranged in parallel with each other may
bc interconncctcd by an intervening passageway (not shown). The passageways 4 18
may be arranged in any pattern relative to each other. The number, pattern, path,
size, andlor the like of the passageways 418 may be selected to provide a predetermined
amount of surface area for thermal communication with the LNG. Although shown as
having a partially cylindrical shape, each passageway 418 may additionally or alternatively
includc any othcr shapc.
Figure 6 is a cross-sectional vlew of a portion of an exemplary embodiment of an
LNG conduit 522 that may be used with the cooling system 10 (Figure I) and/or the
cooling system 110 (Figurc 2). As briefly described above, the LNG conduits described
andlor illustrated herein may be thermally insulated along at least a portion of the length
tht~cof. In the illustrated embodiment of Figure 6, the LNG conduit 522 is a doublewallcd
conduit that extends a lcngth along a central longitudinal axis 524.
The LNG conduit 522 includes an inner wall 526 and an outer wall
528. An intcrior surface 530 of the inner wall 526 defines an inner passageway 532 that is
configured to carry a flow of LNG. The outer wall 528 extends radially (relative to the
central longitudinal axis 524) around the inner wall 526. The outer wall 528 is spaced
radially (relative to the central longitudinal axis 524) apart from the inner wall 526 to
definc an outcr passagcway 534. The outer passageway 534 is dcfincd between an exterior
surface 536 of the inner wall 526 and an interior surface
538 of the outer wall 528. The outer passageway 534 may have any size.
In the illustrated embodiment, the outer passageway 534 contains a vacuum. The
vacuum thermally insulates the LNG flowing through the inner passageway 532. An
cmissivity-reduction layer (not shown) may be provided within the outer passageway 534.
For example, the cmissivity-reduction layer may cxtcnd on the intcrior surface 538 of the
outer wall 528 andlor may extend on the exterior surface 536 of the inner wall 526.
The einissivity-reduction layer may facilitate reducing the einissivity of the outer
passageway 534. In other words, the crnissivity- reduction layer may facilitate reducing the
amount of radiant heat transfer between the LNG flowing within the inner passageway 532
and the ambicnt environment in which the LNG conduit 522 rcsidcs. Examplcs of thc
emissivity-reduction layer include, but are not limited to, multiplayer insulation (MLI), silver
paint, and/or the like.
In alternative to a vacuum, thc outcr passageway 534 may contain onc or more
other thermally insulative materials, such as, but not, limited to, pipe insulation,
mineral wool, glass wool, an elastomeric foam, a rigid foam, polyethylene, aerogel, and/or
thc like. In somc cmbodimcnts whcrcin the outcr passagcway 534 does not contain a
vacuum, a heat tape is applied to the inner wall 526 and/or the outer wall 528. For
cxamplc, hcat tapc may be wrappcd around the cxterior surfacc
536 of thc inner wall 526 along at least a portion of the length of thc LNG conduit 522 to
l'acilitate vaporizing the LNG and/or changing the LNG to a gaseous state. Moreover,
and for cxarnplc, heat tapc may be wrappcd around an extcrior surfacc 540 of the outcr wall
528 and/or may be wrapped around the exterior surface 536 of the inner wall 526 to
facilitate reducing or preventing ice from accumulating around the outer wall 528.
It should be noted that the various embodiments may be implemented in hardware,
software or a combination thereof. The various embodiments and/or components, for
example, the modules, or components and controllers therein, also may be implemented as
part of one or morc computcrs or proccssors. Thc computcr or proccssor may include a
computing device, an inpu t device, a display unit d l d an interface, for example, for
accessing the Internet. The computer or processor may include a microprocessor. The
rnicroproccssor may bc connected to a communication bus. Thc computer or processor
may also include a memory. The memory may include Random Access Memory (RAM)
and Read Only Memory (ROM). The computer or processor further may include a storage
dcvicc, whiclh may bc a hard disk drivc or a removable storage drive such as a solid state
drive, optical disk drive, and the like. The storage device may also be other similar means
for loading computer programs or other instructions into the computer or processor.
AS used hcrcin, the term "computer" or "module" may includc any proccssor-bascd or
microprocessor-based system including systems usmg microcontrollers, reduced instruction set
computers (RISC), ASICs, logic circuits, and any other circuit or processor capable of
cxccuting thc functions dcscribed herein. The above examples arc cxcmplary only, and arc
thus not intended to limit in any way the definition and/or meaning of the term "computer".
The computer or processor exccutes a set of instructions that are stored in one or
more storage elements, in order to process input data. The storage elements may also store
data or other information as desired or needed. The storage element may be in the form of
an information source or a physical memory element within a processing machine.
The set of instructions may include various commands that instruct the computer or
processor as a processing machine to perform specific operations such as the methods and
proccsscs of thc various cmbodimcnts of the invcntion. The sct of instructions may bc in
thc form of a software program. The software may be in various forms such as system
softwarc or application software and which may bc cmbodicd as a tangiblc and nontransitory
computer readable medium. Further, the software may be in the form of a
collection of separate programs or modules, a program module within a larger program
or a portion of a program module. The software also may includc modular programming
in the form of object-oriented programming. The processing of input data by the processing
machine may be in response to operator commands, or in response to results of previous
proccssing, or in responsc to a request madc by another processing machine.
As used herein, the terms "software" and "firmware" are interchangeable,
and include any computer program stored in memory for execution by a computer, including
RAM rncmory, ROM memory, EPROM memory, EEPROM rncmory, and non-volatilc RAM
(NVRAM) memory. The above memory types are exemplary only, and are thus not limiting
as to the types of memory usable for storage of a computer program.
It is to bc understood that the above description is intendcd to be illustrative, and not
restrictive. For example, the above-described embodiments (and/or aspects thereof) may
be used in combination with each other. In addition, many modifications may be made to
adapt a particular situation or material to the teachings of the invention without departing
from its scope. Dimensions, types of materials, orientations of the various components, and
the number and positions of the various components described herein are intendcd to define
paramctcrs of certain embodiments, and arc by no mcans limiting and arc mcrcly cxcmplary
embodiments. Many other embodiments and modifications within the spirit and scope of the
claims will bc apparcnt to thosc of skill in the art upon rcvicwing the above description. Thc
scope of the invention should, therefore, be determined with
reference to the appended claims, along with the full scope of equivalents to which such
claims arc
entitled. In the appended claims, the terms "including" and "in which" are used as the plain-
English cquivalents of the respectivc terms "comprising" and "wherein." Moreovcr,
in the following claims, the tenns "first," "second," and "third," etc. are used merely as
labels, and aTe not intended to impose numerical Tequirements on their objects. Further,
the limitations of the following claims are not written in mcans- plus-function format
and are not intended to be interpreted based on 35 U.S.C. § 112, sixth paragraph, unless
and until such claim limitations expressly use the phrase "mcans for" followed by a
statement of function void of further structure.

We claim :
1. A cooling system for cooling an electrical component, the cooling
system comprising:
a supply of liquid natural gas (LNG);
a heat sink configured to be positioned in thermal communication with
the electrical component;
an LNG conduit configured to be intercoimected between the heat sink
and the supply of LNG such that the LNG conduit is configured to carry LNG from
the supply to the heat sink; and
a pump configured to be operatively connected in fluid communication
with the supply of LNG, the pump being configured to move LNG within the LNG
conduit from the supply to the heat sink.
2. The cooling system of claim I, wherein the supply of LNG
comprises a fuel tank of an aircraft engine.
3. The cooling system of claim I, wherein the pump comprises a fuel
pump for an aircraft engine.
4. The cooling system of claim 1, wherein the LNG is used as a fuel
for an engine, the heat sink being configured to increase the temperature of the LNG
toward a supply temperature at which the LNG is supplied to the engine in a gaseous
state.
5. The cooling system of claim 1, further comprising the electrical
component, the electrical component being configured for use on-board an aircraft.
6. The cooling system of claim 1, wherein the heat sink comprises a
fluid block having at least one passageway for receiving a flow of the LNG from the
LNG conduit.
23
7. The cooling system of claim 1, wherein the LNG conduit comprises
an insulated segment that extends a length from the supply of LNG to the heat sink,
the insulated segment being thermally insulated along at least a portion of the length
thereof, the LNG conduit comprising an uninsulated segment that extends from the
insulated segment and is engaged with the heat sink
8. The cooling system of claim 1, wherein the heat sink comprises an
exterior surface, the LNG conduit being engaged with the exterior surface of the heat
sink.
9. The cooling system of claim 1, wherein the heat sink comprises an
interior surface, the LNG conduit being engaged with the interior surface of the heat
sink.
10. The cooling system of claim 1, wherein the heat sink is configured
to be positioned in thermal communication with the electrical component through at
least one of:
engagement with the electrical component; or
engagement with a thermal interface material that is engaged with the
electrical component.
11. The cooling system of clajm I, wherein the LNG conduit
comprises an inner wall and an outer wall, the inner wall defining an inner
passageway that is configured to carry the LNG, an outer passageway being defined
between the inner wall and the outer wall, the outer passageway comprising a
vacuum.
12. A method for cooling an electrical component, the method system
compnsmg:
24
supplying a flow of liquid natural gas (LNG) from a supply of the
LNG to a heat sink that is positioned in thermal communication with the electrical
component; and
dissipating heat from the electrical component by absorbing heat from
the heat sink using the LNG.
13. The method of claim 12, wherein supplying the flow of LNG
comprises supplying the flow of LNG from a fuel tank of an aircraft engine.
14. The method of claim 12, wherein dissipating heat from the
electrical component by absorbing heat from the heat sink using the LNG comprises
at least partially vaporizing the LNG.
15. The method of claim 12, wherein dissipating heat from the
electrical component by absorbing heat from the heat sink using the LNG comprises
increasing the temperature of the LNG toward a supply temperature at which the LNG
is supplied to an engine in a gaseous state for use as by the engine as fuel.
16. The method of claim 12, wherein the electrical component is
configured for use on-board an aircraft.
17. An aircraft comprising:
an airframe;
an electrical component on-board the airframe; and
a cooling system on-board the airframe, the cooling system
comprising:
a supply of liquid natural gas (LNG);
a heat sink positioned in thermal communication with the elecfrical
component;
25
an LNG conduit interconnected between the heat sink and the supply
of LNG such that the LNG conduit is configured to carry LNG lirom the supply to the
heat sink; and
a pump operatively connected in fluid communication with the supply
of LNG, the pump being configured to move LNG within the LNG conduit from the
supply to the heat sink.
18. The aircraft of claim 17, wherein the aircraft includes an engine
on-board the airframe, the aircraft including a fuel tank on board the airframe for
supplying the engine with LNG in a gaseous state, the fuel tank comprising the supply
of LNG.
19. The aircraft of claim 17, wherein the aircraft includes an engine
on-board the airframe, the LNG being used as a fiiel for the engine in a gaseous state,
the heat sink being configured to increase the temperature of the LNG toward a
supply temperature at which the LNG is supplied to the engine in the gaseous state.
20. The aircraft of claim 17, wherein the LNG conduit comprises an
inner wall and an outer wall, the inner wall defining an inner passageway tlhatis
configured to carry the LNG, an outer passageway being defined between the inner
wall and the outer wall, the outer passageway comprising a vacuum.