Patent Description:
During ascent and decent operations of aircrafts, control and propulsion surfaces can require de-icing and/or anti-icing below a predetermined altitude so as to reduce or prevent ice buildup on exterior surfaces of the aircraft. Some known de-icing and/or anti-icing techniques include using bleed air from turbine engines to heat the control and propulsion surfaces. Other known de-icing and/or anti-icing techniques include using electric heating at the control and propulsion surfaces. However, both of these ice reducing techniques are a parasitic drain on other systems when in operation (e.g., compressed air from the turbine engine or larger generators producing electric power). Additionally, both of these ice reducing techniques are independent systems that are only used for de-icing and/or anti-icing, and de-icing and/or anti-icing is not required for the entire flight cycle of the aircraft. It is desirable to improve efficiency and performance of aircrafts.

In <CIT> there is disclosed an electric power generation system which employs a thermoelectric generator placed between an aircraft inner skin and an aircraft outer skin. The thermoelectric generator is configured to utilize a thermal differential between the inner and outer skin to generate electricity, wherein <CIT> thus converts heat which is removed from the heated cabin air to electrical power. A similar system is described in <CIT>.

In an aspect, the present invention is an aircraft including: an exterior skin wall including an inside surface and an outside surface; an electrical power circuit; one or more thermal energy generating components operating on power from the electrical power circuit; at least one thermal management circuit configured to channel a flow of coolant fluid and collect thermal waste energy from the one or more thermal energy generating components; one or more heat exchangers coupled in thermal contact to the exterior skin wall and coupled in fluid communication with the at least one thermal management circuit downstream from the one or more thermal energy generating components, wherein the one or more heat exchangers are adapted to transfer thermal energy from the flow of coolant fluid to the exterior skin wall for removal from the at least one thermal management circuit; and a thermoelectric generator including thermoelectric interface material extending between the inside surface of the exterior skin wall and the one or more heat exchangers, wherein the thermoelectric generator is configured to convert heat flux between the flow of coolant fluid within the one or more heat exchangers and atmosphere surrounding the outside surface of the exterior skin wall into electrical energy and is coupled in electric communication to the electrical power circuit.

The aircraft may also include one or more of the following features individually or in non-exclusive combinations. In an example, an electric heater is coupled in thermal contact to the exterior skin wall. In another example, the electric heater is disposed between the one or more heat exchangers and the inside surface of the exterior skin wall. In still another example, an insulating material layer is included, wherein the one or more heat exchangers and the thermoelectric generator being disposed between the insulating material layer and the inside surface of the exterior skin wall. In yet another example, the exterior skin wall is a leading surface of one or more control or propulsion surfaces of the aircraft.

In an example, an electrical power circuit is included, the thermoelectric generator further includes a thermoelectric module formed from the thermoelectric interface material, and the thermoelectric module is coupled to the electrical power circuit and adapted to directly generate the electrical energy from the heat flux within the thermoelectric interface material. In another example, an electric heater is coupled in thermal contact to the exterior skin wall and operably coupled to the electrical power circuit. In still another example, the at least one thermal management circuit includes tubing for the flow of coolant fluid, and at least a portion of the tubing between the one or more thermal energy generating components and the one or more heat exchangers is routed along at least a portion of one or more of a ducted shroud, a pylon, and a wing of the aircraft and thermally coupled thereto.

In another aspect, the present invention is a method of generating electrical energy from thermal waste energy and removing thermal waste energy in an aircraft, the method including: collecting in a flow of coolant fluid thermal waste energy from one or more thermal energy generating components operating on power from an electrical power circuit of the aircraft; channeling the flow of coolant fluid towards one or more heat exchangers downstream of the one or more thermal energy generating components, wherein the one or more heat exchangers are coupled in thermal contact to an exterior skin wall of the aircraft; removing thermal energy from the flow of coolant fluid at the one or more heat exchangers by transferring thermal energy from the flow of coolant fluid to the exterior skin wall; converting heat flux between the flow of coolant fluid and atmosphere surrounding an outside surface of the exterior skin wall to electrical energy via a thermoelectric generator, wherein the thermoelectric generator includes thermoelectric interface material extending between an inside surface of the exterior skin wall and the one or more heat exchangers; and transferring the electrical energy from the thermoelectric generator to the electrical power circuit of the aircraft.

The method may also include one or more of the following features individually or in non-exclusive combinations. In an example, the method can include reducing or preventing ice formation at the exterior skin wall by transferring thermal energy from the flow of coolant fluid to the exterior skin wall. In another example, reducing or preventing ice formation at the exterior skin wall also includes heating the exterior skin wall by an electric heater coupled in thermal contact to the exterior skin wall. In still another example, the step of transferring thermal energy from the flow of coolant fluid to the exterior skin wall and the step of heating the exterior skin wall by the electric heater occur concurrently. In an example, the method can include insulating the one or more heat exchangers at the exterior skin wall of the aircraft.

A variety of additional inventive aspects will be set forth in the description that follows. The inventive aspects can relate to individual features and to combinations of features. It is to be understood that both the forgoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the broad inventive concepts upon which the examples disclosed herein are based.

The accompanying drawings, which are incorporated in and constitute a part of the description, illustrate several aspects of the present invention. A brief description of the drawings is as follows.

The systems and methods describe herein have features that capture thermal waste energy from thermal energy generating components on an aircraft and use the thermal waste energy to provide electric power generation and heat dissipation. Additionally, the heat dissipation functionality can be used to reduce icing on the aircraft as required or desired. As such, aircraft efficiency and performance are increased. The system includes a heat exchanger that is thermally coupled to an exterior skin wall of the aircraft. The heat exchanger is coupled to a thermal management circuit that captures the thermal waste energy and transfers it to the heat exchanger. In an aspect, a coolant fluid is used to cool the thermal energy generating components and capture the thermal waste energy. At the heat exchanger, the thermal waste energy is dissipated from the coolant fluid to the atmosphere and removed from the circuit.

Because this dissipation of thermal waste energy heats an outside surface of the exterior skin wall, the heat exchanger can be disposed at locations on the aircraft that require anti-icing and/or de-icing during ascent and descent operations of the aircraft below predetermine altitudes. For example, the heat exchanger is located at leading edge portions of the exterior skin wall and at control or propulsion surfaces of the aircraft. In contrast to known existing anti-icing and/or de-icing systems (e.g., bleed air systems and electronic heat systems), by using thermal waste energy, a dedicated and independent ice reducing system that may not be utilized for the entire flight cycle is reduced or eliminated. Thus, aircraft weight and parasitic loads on engines and generators are reduced, and aircraft efficiency and performance are increased.

Additionally, the heat flux between the heat exchanger with the heated coolant fluid and the exterior skin wall exposed to the atmosphere is relatively consistent, and as such, the system includes a thermoelectric generator that is used to generate electric power for the aircraft. The thermoelectric generator can be used for most of, or the entire, flight cycle to augment the electric power sources on the aircraft and reduce the size thereof. Thereby, also increasing aircraft efficiency and performance of the aircraft. Accordingly, the systems and methods described herein are configured to capture waste heat from the aircraft and repurpose the waste heat to reduce the power draw from a battery required to reduce icing of aircraft surfaces and reduce the heat load on radiators resulting in a reduction of size, and thereby, a reduction of total aircraft weight.

<FIG> is a schematic view of an aircraft <NUM>. The aircraft <NUM> includes one or more engines <NUM>, for example, a gas turbine, disposed on wings <NUM>. Additionally, a tail <NUM> is disposed at the tail end of the aircraft <NUM> opposite a nose end <NUM>. The aircraft <NUM> has an exterior skin wall <NUM> that is exposed to the atmosphere. Portions of the exterior skin wall <NUM> form leading edges <NUM> of the aircraft <NUM> in relation to the direction of travel. These leading edges <NUM> can be formed on one or more aerodynamic control or propulsion surfaces (e.g., wings <NUM>, tail <NUM>, nose <NUM>, pylons, ducted shrouds, etc.) that require anti-icing and/or de-icing during ascent and decent operations of the aircraft <NUM> and below a predetermined altitude. As used herein, anti-icing may refer to reducing or preventing the creation of ice on the surface of the aircraft, while de-icing may refer to reducing (e.g., melting) ice already formed on the surface of the aircraft. Generally, the icing system described herein may be utilized for anti-icing and/or de-icing functions as required or desired.

As illustrated in <FIG>, the aircraft <NUM> is a commercial airplane with gas turbine engines. It should be appreciated that the systems and devices described herein can be used in any other type of aircraft as required or desired. For example, military aircrafts, rotorcrafts (e.g., helicopters), unpowered aircrafts such as gliders, propeller aircrafts, electric aircrafts, and the like. In an aspect, the aircraft <NUM> may be a vertical take-off and landing (VTOL) aircraft and the leading edges <NUM> can include, but are not limited to, the leading edges of pylon and wing surfaces, and/or a ducted shroud.

The aircraft <NUM> also includes an electrical power circuit <NUM> which generates, controls, and distributes power to electrical loads <NUM> on the aircraft <NUM>. The electrical loads <NUM> can be any component on the aircraft <NUM> that requires electrical power to operate, such as, but not limited to, avionics equipment, flight deck displays, flight controls, in-flight entertainment, power distribution units, pumps, motors, mechanical devices, and the like. Furthermore, as more and more electrical components are utilized on aircrafts, the required electrical power required to operate the aircraft <NUM> is ever increasing. The various components of the electrical power circuit <NUM> can be serviced by a forward electrical equipment bay <NUM> and/or an aft electrical equipment bay <NUM>.

In an aspect, the electrical power circuit <NUM> includes power generators <NUM> on the engines <NUM> and one or more auxiliary power units <NUM> as required or desired to generate power. Additionally, one or more batteries or fuel cells (not shown) can be included to store power. Generally, the electrical power circuit <NUM> includes multiple layers of redundancy for safe operation of the aircraft <NUM>.

The components powered at the electrical loads <NUM> generate thermal energy from power consumption that is collected and removed from the electrical power circuit <NUM>. This collected thermal energy is generally considered waste thermal energy and is removed from the aircraft <NUM>. To manage the thermal load of the electrical power circuit <NUM>, the aircraft <NUM> includes one or more thermal management circuits <NUM>. The thermal management circuit <NUM> is thermally coupled to the thermal energy generating components in the electrical power circuit <NUM> such that the thermal waste energy is collected by a flow of coolant fluid past the electrical loads <NUM>. The coolant fluid can be a liquid or a gas fluid. In an aspect, the coolant fluid is a liquid, such as, ethylene glycol and water, propylene glycol and water, polyalphaolefin, and the like. The thermal management circuit <NUM> can include any number of components that enable coolant fluid to be channeled therethrough for collecting and managing thermal waste energy, such as, but not limited to, piping, pumps, valves, reservoirs, and the like.

In the example, one or more heat exchangers <NUM> are coupled in fluid communication with the thermal management circuit <NUM>. The heat exchangers <NUM> are coupled in thermal contact with the exterior skin wall <NUM> of the aircraft <NUM> and are adapted to transfer thermal energy from the coolant fluid to the exterior skin wall <NUM> for removal from the thermal management circuit <NUM> and dissipation into the atmosphere. In an aspect, the heat exchangers <NUM> are disposed adjacent to one or more of the leading edges <NUM> of the aircraft <NUM>. In this location, the heat exchangers <NUM> and the thermal management circuit <NUM> can be used to reduce or prevent ice formation during ascent and descent operations of the aircraft <NUM>. That is, when required or desired the transfer of thermal energy from the heated coolant fluid flow towards the exterior skin wall <NUM> and the cooler atmospheric side is utilized to de-ice and/or anti-ice the exterior skin wall <NUM> and reduce or prevent ice from forming on its outside surface. It should be appreciated, that the heat exchangers <NUM> can be located in other areas of the aircraft <NUM> and utilized to dissipate thermal energy from the thermal management circuit <NUM> without functioning as a de-icing and/or anti-icing component as required or desired.

As illustrated in <FIG>, the thermal management circuit <NUM> is thermally coupled to the electrical power circuit <NUM>. It should be appreciated, that the thermal management circuit <NUM> can additionally, or alternatively, be coupled in thermal communication to any other circuit within the aircraft <NUM> that has components that generate thermal energy. For example, heat for the heat exchangers <NUM> can be collected from a hydraulic circuit (not shown), a fuel circuit (not shown), an engine circuit (not shown), or any other circuit within the aircraft <NUM>. By using the thermal management circuit <NUM> to de-ice and/or anti-ice the leading edges <NUM>, a separate dedicated ice reducing system is not necessary needed (e.g., a bleed air de-icing system or an electric heating system), or the size of the separate ice reducing system can be reduced, thereby increasing aircraft efficiencies and performance by reducing parasitic loads on engines and reducing weight.

In some aspects, the heat exchangers <NUM> may be separated into zones within the aircraft <NUM> such that the heated coolant fluid within the thermal management circuit <NUM> is concentrated in specific areas as required or desired. Additionally or alternatively, at least a portion of the thermal management circuit <NUM> that is between the thermal generating component and the heat exchanger <NUM> may be routed through tubing that is in contact with at least a portion of the leading edges <NUM> that are to be de-iced or anti-iced. For example, the tubing for the thermal management circuit <NUM> may be routed to be in contact with an internal surface of a ducted shroud of the aircraft <NUM> for de-icing and/or anti-icing and upstream of the heat exchanger <NUM>. In other examples, the tubing may be routed to be in contact with a leading edge of a wing or a pylon. This configuration can decrease the thermal load on the heat exchanger <NUM>, and thereby size, to further increase efficiency and performance of the aircraft <NUM>.

Additionally, between the heat exchangers <NUM> with the heated coolant fluid and the exterior skin wall <NUM> exposed to the atmosphere, a high heat flux is present. In the example, this heat flux is captured via a thermoelectric generator <NUM> and converted into electrical energy. The thermoelectric generator <NUM> is coupled in electric communication to the electrical power circuit <NUM> so that the captured electrical energy can be used within the aircraft <NUM> as required or desired. By generating electrical energy from thermal waste energy, the aircraft is more efficient and power generation units, like the generators <NUM>, can be reduced in size while increasing aircraft performance. The thermoelectric generator <NUM> can also extend the range of an aircraft and make the aircraft more efficient.

<FIG> is a schematic view the thermal management circuit <NUM> that generates electrical energy from thermal waste energy and also removes the thermal waste energy from the aircraft <NUM> (shown in <FIG>). During operation of the aircraft, one or more components <NUM> draw electric power <NUM> from a power source <NUM> within the electrical power circuit <NUM>. These components <NUM> generate thermal energy in the form of heat that is collected by the thermal management circuit <NUM>. The thermal management circuit <NUM> is thermally coupled to the component <NUM> and is configured to channel a coolant fluid <NUM> that cools the component <NUM> and collects the waste thermal energy from the component <NUM>. The heated coolant fluid <NUM> is channeled through one or more heat exchangers <NUM> that are downstream from the thermal energy generating components <NUM>. The heat exchanger <NUM> is coupled in thermal contact to the exterior skin wall <NUM> of the aircraft with an inside surface <NUM> and an outside surface <NUM> that is exposed to the atmosphere. This configuration enables thermal waste energy <NUM> collected within the heated coolant fluid <NUM> to be dissipated into the atmosphere through the exterior skin wall <NUM>. Additionally, this dissipation of thermal waste energy <NUM> at the exterior skin wall <NUM> can facilitate de-icing and/or anti-icing of the outside surface <NUM> as required or desired.

The heat exchanger <NUM> can be any type of heat exchanger that enables the thermal waste energy <NUM> to be dissipated through the exterior skin wall <NUM> as described herein. For example, the heat exchanger <NUM> may be a tube-type heat exchanger. In another example, the heat exchanger <NUM> may be additively manufactured cavities that promote heat transfer. Other heat exchanger types are also contemplated herein.

Additionally, because the atmosphere at the outside surface <NUM> of the exterior skin wall <NUM> is lower in temperature than the heated coolant fluid <NUM>, there is heat flux therebetween, and this heat flux is captured by the thermoelectric generator <NUM>. The thermoelectric generator <NUM> includes thermoelectric interface material <NUM> that extends between the inside surface <NUM> of the exterior skin wall <NUM> and the heat exchanger <NUM>. The thermoelectric interface material <NUM> is characterized in having both high electrical conductivity and low thermal conductivity. The thermoelectric interface material <NUM> forms a thermoelectric module <NUM> that is adapted to directly generate electrical power <NUM> from the heat flux within the thermoelectric interface material <NUM>. The thermoelectric module <NUM> is coupled in electric communication with the electrical power circuit <NUM> so that the electrical power <NUM> generated therefrom can be used in the aircraft as required or desired. For example, power various aircraft systems while enabling the power source <NUM> to be downsized. The thermoelectric generator <NUM> enables for the thermal waste energy <NUM> to be additionally utilized for generating electrical power <NUM> for the aircraft.

In some examples, the thermoelectric generator <NUM> may include a plurality of thermoelectric generators electronically coupled together in parallel or series. To link together the thermoelectric modules <NUM> of multiple thermoelectric generators <NUM> and/or couple the thermoelectric generators <NUM> to the electrical power circuit <NUM>, integrated or printed wiring can be utilized. In an aspect, the thermoelectric generator <NUM> and the wiring may be applied directly to the inside surface <NUM> of the exterior skin wall <NUM> of the aircraft. In another aspect, the thermoelectric generator <NUM> and wiring can be applied to a flexible decal, sheet, adhesive attachment, or the like that is applied to the inside surface <NUM> of the exterior skin wall <NUM> after initial structural fabrication. As described herein, wiring may be considered to mean gaged electrical wire applied or embedded with a structure or sheet, or may additionally or alternatively be printed conductive pathways as required or desired.

Turning back to the de-icing and/or anti-icing functionality of the heat exchanger <NUM>, in some examples, the thermal waste energy <NUM> may need to be augmented so that the outside surface <NUM> of the exterior skin wall <NUM> is heated to a temperature that provides the de-icing and/or anti-icing functionality. In this example, an electric heater <NUM> can be coupled in thermal contact to the inside surface <NUM> of the exterior skin wall <NUM>. The electric heater <NUM> is operably coupled to the electrical power circuit <NUM> such that electric power <NUM> is used to heat the exterior skin wall <NUM>. The electric heater <NUM> can be used concurrently with the heat exchanger <NUM>, and as such, the draw of electric power <NUM> is lower than when compared to a de-icing and/or anti-icing system that only uses electric heaters. The electric heater <NUM> can be any type of electric heater <NUM> that enables the exterior skin wall <NUM> to de-ice and/or anti-ice as described herein. For example, the electric heater <NUM> can be a resistive film that is adhered to the inside surface <NUM>. In another example, the electric heater <NUM> may be resistive coils. Other electric heater configurations are also contemplated herein.

In the example, the electric heater <NUM> is disposed between the heat exchanger <NUM> and the inside surface <NUM> of the exterior skin wall <NUM>. In an aspect, the electric heater <NUM> and the thermoelectric generator <NUM> may be in series and side-by-side of one another so that they run parallel with each other along the inside surface <NUM> of the exterior skin wall <NUM>. In other aspects, the electric heater <NUM> and the thermoelectric generator <NUM> may be in a layered configuration with respect to the exterior skin wall <NUM>.

<FIG> is a partial cross-sectional view of the thermal management circuit <NUM> disposed within the aircraft <NUM> (shown in <FIG>). As illustrated in <FIG>, the leading edge <NUM> of the exterior skin wall <NUM> is shown and is a surface of a control or propulsion component of the aircraft. For example, wings, pylons, nose, tail, ducted shrouds, and/or the like. Adjacent the inside surface of the exterior skin wall <NUM> is the thermoelectric interface material <NUM> along with the electric heater <NUM> and thermoelectric generator <NUM>. Additionally, the heat exchanger <NUM> is provided, and the heat exchanger <NUM> can be insulated by an insulating material layer <NUM>. In the example, the heat exchanger <NUM>, the thermoelectric generator <NUM>, and the electric heater <NUM> are all disposed between the insulating material layer <NUM> and the exterior skin wall <NUM>. This configuration ensures that the thermal waste energy is directed and dissipates toward the exterior skin wall <NUM> rather than back into the components of the aircraft. Additionally, the insulating material layer <NUM> traps heat generated by the electric heater <NUM> into the exterior skin wall <NUM> and the generated heat is not distributed towards the components of the aircraft. In an aspect, one or more of the heat exchanger <NUM>, the thermoelectric generator <NUM>, and the electric heater <NUM> may be contoured to the shape of the exterior skin wall <NUM>.

In operation, both the heat exchanger <NUM> and the thermoelectric generator <NUM> utilize the heated coolant fluid as the hot side of the system and the atmosphere outside of the exterior skin wall <NUM> as the cold side of the system. As such, for both components heat flux is in a direction away from the heat exchanger <NUM> and towards the exterior skin wall <NUM>. This direction can provide heating for de-icing and/or anti-icing functions and/or general waste thermal energy dissipation to the atmosphere via the heat exchanger <NUM>, and electric power generation via the thermoelectric generator <NUM>. Because aircrafts are using ever-increasing power loads, the thermal management circuit <NUM> is able to supply a continuous flow of heated coolant fluid to the heat exchanger <NUM>. Additionally, the cooler atmosphere outside of the exterior skin wall <NUM> is also consistent. As such, the environment between the heat exchanger <NUM> hot side and the atmospheric cold side is relatively consistent during operation of the aircraft, thereby creating a reliable system for utilizing the thermoelectric generator <NUM>. The thermoelectric generator <NUM> can also operate during most of or the entire flight cycle of the aircraft.

In some examples, the electric heater <NUM> and the thermoelectric generator <NUM> may be an integrated device. As such, the integrated device can generate heat with electrical input, but also generate electricity with heat energy input. Because, de-icing and/or anti-icing is required only during ascending and descending, during most of the operational time of the aircraft the integrated device can be used as a generator producing electrical power. This integrated device also has built in inherent safety redundancy as either the heat exchanger or electric heater can operate independently.

Wiring <NUM> is used to electronically couple together multiple thermoelectric generators <NUM> and/or electronically couple the thermoelectric generators <NUM> to the electrical power circuit. In an aspect, the thermoelectric generator <NUM> and the wiring <NUM> may be applied directly to the inside surface <NUM> of the exterior skin wall <NUM> of the aircraft. In another aspect, the thermoelectric generator <NUM> and wiring can be applied to a flexible decal, sheet, adhesive attachment, or the like that is applied to the inside surface <NUM> of the exterior skin wall <NUM> after initial structural fabrication. The wiring <NUM> can be integrated or printed electronic wiring as required or desired.

<FIG> is a flowchart illustrating a method <NUM> of generating electrical energy from thermal waste energy and removing thermal waste energy in an aircraft. In aspects, the method <NUM> can be performed with one or more of the aircraft components described above in reference to <FIG>. The method <NUM> begins with collecting thermal waste energy from one or more thermal energy generating components on the aircraft in a flow of coolant fluid (operation <NUM>). For example, a thermal management circuit is thermally coupled to the aircraft component and is used to extract heat into the flow of coolant fluid therein. In an aspect, the thermal energy generating component may be part of an electrical power circuit. In other aspects, the thermal energy generating component may be part of an hydraulic circuit, engine system, gear box system, or the like.

The flow of coolant fluid is channeled toward one or more heat exchangers downstream of the one or more thermal energy generating components (operation <NUM>). The heat exchangers being coupled in thermal contact to an exterior skin wall of the aircraft. In an example, the heat exchangers are disposed adjacent to a leading edge of one or more control or propulsion surfaces of the aircraft. At the one or more heat exchangers, thermal energy is removed from the flow of coolant fluid (operation <NUM>). For example, the thermal energy is transferred from the flow of coolant fluid to the exterior skin wall. Additionally, heat flux between the flow of coolant fluid and the atmosphere surrounding an outside surface of the exterior skin wall is converted to electrical energy via a thermoelectric generator (operation <NUM>). The thermoelectric generator can include thermal interface material that extends between an inside surface of the exterior skin wall the heat exchangers.

In some examples, by transferring thermal energy from the flow of coolant fluid to the exterior skin wall during operation <NUM> the exterior skin wall is de-iced and/or anti-iced. In an aspect, the de-icing and/or anti-icing only occurs below predetermined altitudes and during ascent and descent operations of the aircraft. The de-icing and/or anti-icing can also include heating the exterior skin wall by an electric heater coupled in thermal contact to the exterior skin wall (operation <NUM>). In some examples, the step of transferring thermal energy from the flow of coolant fluid to the exterior skin wall during operation <NUM> and the step of heating the exterior skin wall by the electric heater in operation <NUM> occur concurrently. This configuration reduces the amount of electric power required for de-icing and/or anti-icing operations.

The method <NUM> can also include transferring the electrical energy from the thermoelectric generator to an electrical power circuit of the aircraft (operation <NUM>). By generating electrical power for the aircraft from waste thermal energy produced by operation of the aircraft, efficiency and performance of the aircraft are increased. Additionally or alternatively, the one or more heat exchangers can be insulated at the exterior skin wall of the aircraft (operation <NUM>).

<FIG> is a perspective view of a ducted shroud <NUM>. <FIG> is a cross-sectional view of the ducted shroud <NUM> shown in <FIG> taken along line <NUM>-<NUM>. Referring concurrently to <FIG>, the ducted shroud <NUM> may house a fan <NUM> for a turbine engine and is a component of the aircraft <NUM> (shown in <FIG>). The ducted shroud <NUM> includes the exterior skin wall <NUM> that is exposed to a flow of air <NUM> during operation and that may require de-icing and/or anti-icing. As such, one or more tubes <NUM> that are configured to house coolant fluid are routed to be in contact with the inside surface <NUM> of the exterior skin wall <NUM> for de-icing and/or anti-icing and heating the exterior skin wall <NUM>. In other examples, one or more of the tubes <NUM> may be routed to be in contact with the exterior skin wall of a wing or a pylon as required or desired.

<FIG> is a schematic view of the thermoelectric generator <NUM> of the thermal management circuit <NUM> (shown in <FIG>). In this example, the thermoelectric generator <NUM> is disposed between the heat exchanger <NUM> and the exterior skin wall <NUM> and similar to the configuration shown in <FIG>. The heat exchanger <NUM> includes liquid flow channels that dissipate heat towards a portion <NUM> of the exterior skin wall <NUM> that is heated for de-icing and/or anti-icing. In some aspects, an electric heater (not shown) may be additionally included. A portion <NUM> of the exterior skin wall <NUM> that de-icing and/or anti-icing is not required or desired and is cold may not include the thermoelectric generator <NUM>.

<FIG> is another schematic view of the thermoelectric generator <NUM> of the thermal management circuit <NUM> (shown in <FIG>). In this example, the heat exchanger <NUM> may be disposed directly adjacent to the heated portion <NUM> of the exterior skin wall <NUM> for de-icing and/or anti-icing. The heat exchanger <NUM> may include a feature <NUM> that protrudes from the heat exchanger <NUM> and is heated by coolant flow. The thermoelectric generator <NUM> is placed between the feature <NUM> and the cold portion <NUM> of the exterior skin wall <NUM>. As such, the feature <NUM> extends outward from the heat exchanger <NUM> and the de-icing and/or anti-icing system. By placing the thermoelectric generator <NUM> adjacent to the heated portion <NUM> and in contact with the cold portion <NUM>, the temperature delta that the thermoelectric generator <NUM> experiences can increase its efficiency. In an aspect, insulation <NUM> may be disposed between the thermoelectric generator <NUM> and the heat exchanger <NUM>.

In the systems and methods described above, a heat exchanger and thermoelectric generator are used to remove thermal waste energy from a thermal management circuit and to generate electric power for the aircraft. The removal of thermal waste energy can act as a de-icing and/or anti-icing function for outside surfaces of the aircraft as required or desired during flight operation. When de-icing and/or anti-icing in not required or desired, the thermal waste energy can just be dissipated to the atmosphere. In an aspect, an electric heater may be used to augment de-icing and/or anti-icing functionality.

By using the thermal management circuit to reduce or prevent icing of the aircraft, a separate dedicated de-icing and/or anti-icing system is not necessary needed (e.g., a bleed air de-icing system or an electric heating system), or the size of the separate de-icing or anti-icing system can be reduced, thereby increasing aircraft efficiencies by reducing parasitic loads on engines and reducing weight. Additionally, by generating electrical energy from thermal waste energy, the aircraft is more efficient and power generation units can be reduced in size while increasing aircraft performance. The thermoelectric generator can also extend the range of an aircraft and make the aircraft more efficient.

This disclosure describes some examples of the present invention with reference to the accompanying drawings, in which only some of the possible examples were shown. Other aspects can, however, be embodied in many different forms and should not be construed as limited to the examples set forth herein. Rather, these examples were provided so that this disclosure was thorough and complete and fully conveyed the scope of the possible examples to those skilled in the art. Any number of the features of the different examples described herein may be combined into one single example and alternate examples having fewer than or more than all of the features herein described are possible. It is to be understood that terminology employed herein is used for the purpose of describing particular examples only and is not intended to be limiting. It must be noted that, as used in this specification, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

Claim 1:
An aircraft (<NUM>) comprising:
an exterior skin wall (<NUM>) comprising an inside surface (<NUM>) and an outside surface (<NUM>);
an electrical power circuit (<NUM>);
one or more thermal energy generating components (<NUM>) operating on power from the electrical power circuit (<NUM>);
at least one thermal management circuit (<NUM>) configured to channel a flow of coolant fluid and collect thermal waste energy from the one or more thermal energy generating components (<NUM>);
one or more heat exchangers (<NUM>) coupled in thermal contact to the exterior skin wall (<NUM>) and coupled in fluid communication with the at least one thermal management circuit (<NUM>) downstream from the one or more thermal energy generating components (<NUM>), wherein the one or more heat exchangers are adapted to transfer thermal energy from the flow of coolant fluid to the exterior skin wall for removal from the at least one thermal management circuit; and
a thermoelectric generator (<NUM>) comprising thermoelectric interface material extending between the inside surface (<NUM>) of the exterior skin wall (<NUM>) and the one or more heat exchangers (<NUM>), wherein the thermoelectric generator is configured to convert heat flux between the flow of coolant fluid within the one or more heat exchangers and atmosphere surrounding the outside surface (<NUM>) of the exterior skin wall (<NUM>) into electrical energy and is coupled in electric communication to the electrical power circuit (<NUM>).