ICE PROTECTION SYSTEM USING RESIDUAL HEAT RECOVERY

Abstract

Ice protection system for use with an aircraft including an electric motor to drive an aircraft propulsion structure. The electric motor is cooled by a heat transfer fluid that flows through or over the electric motor to extract heat from it. The ice protection system uses the heat transfer fluid heated by the electric motor to provide anti-icing and de-icing functionality. Figure for abbreviation: Fig. 1

Description

Title of the invention: ICE PROTECTION SYSTEM USING RESIDUAL HEAT RECOVERY REFERENCE TO A RELATED APPLICATION

[0001] This application claims the benefit of Indian provisional patent application number 202411045215, filed on June 12, 2024, the disclosure of which is incorporated herein by reference in its entirety. TECHNOLOGICAL BACKGROUND

[0002] Systems for recovering residual heat to be used for other functionalities are known. For example, documents EP 3 789 301, US 2020 / 0 377 222 and US2023 / 0 070 111 disclose systems for using heat from an aircraft electric motor to provide additional functionalities such as de-icing. SUMMARY

[0003] An anti-icing system for use with an aircraft, including an electric motor for driving an aircraft propulsion structure. The electric motor is cooled by a heat transfer fluid that flows through or by the electric motor to extract heat from it. The anti-icing system uses the heat transfer fluid heated by the electric motor to provide anti-icing and de-icing functionality.

[0004] One aspect of this disclosure relates to an ice protection system configured to use waste heat to prevent ice formation (anti-icing) or to melt existing ice (de-icing). In some examples, the ice protection system may be used on an electric aircraft such as an electric vertical takeoff and landing (eVTOL) aircraft. In some examples, the ice protection system may use heat from an electric motor and inverter used to power a propulsion component (e.g., a propulsion rotor) of the aircraft. In some examples, the ice protection system may also use heat from one or more batteries.In some examples, a skin-type heat exchanger can be used to transfer heat to parts of the aircraft prone to icing, such as the wings, tail, pylons, and nacelle. In some examples, the skin-type heat exchanger may define a plurality of passages through which a heat transfer fluid (e.g., a glycol-based fluid) flows. In one example, the heat exchanger... A skin-type heat transfer membrane can exhibit a composite construction with different materials that work together to define the heat transfer pathways. In some examples, the composite construction may include a collector structure (e.g., a molded structure made of a lower-density material such as a non-metallic material, including plastic) with a primary conductivity that works in conjunction with a heat transfer layer (e.g., a heat sink made of a higher-density material such as a metallic layer like copper or aluminum, or a thermally conductive composite) with a secondary conductivity greater than the primary conductivity to define the heat transfer pathways. In one example, the heat transfer layer may have a relatively thin, sheet-like construction.In some examples, the passages may define a primary flow path and a secondary flow path. In some examples, the primary flow path provides an anti-icing function while the secondary flow path provides a de-icing function.

[0005] Various additional aspects will be set forth in the following description. These aspects may relate to individual features and combinations of features. It should be understood that the preceding general description and the detailed description that follows are merely examples and explanations and are not exhaustive of the general inventive concepts on which the embodiments disclosed herein are based. Brief description of the drawings

[0006] [Fig.1] is a diagram of an ice protection system in accordance with the principles of this disclosure;

[0007] [Fig.2] schematically represents an aircraft component (for example, a wing) exhibiting an example of a heat transfer structure with anti-icing and de-icing flow paths;

[0008] [Fig.3] represents an example of a heat transfer structure in accordance with the principles of this disclosure which can be integrated into a component (e.g., a wing) of an aircraft;

[0009] [Fig. 4] is a cross-sectional view taken through a portion of a heat transfer structure of [Fig. 3]; and

[0010] [Fig.5] is a flowchart describing an example of control logic / strategy for controlling ice protection systems in accordance with the principles of this disclosure. DETAILED DESCRIPTION

[0011] We will now refer in detail to the exemplary aspects of this disclosure that are illustrated in the accompanying drawings. Wherever possible, the same numerical references will be used throughout the drawings to refer to the same or a similar structure.

[0012] Figure 1 represents an ice protection system 20 in accordance with the principles of this disclosure. The ice protection system 20 can be used on an aircraft to provide anti-icing and de-icing functionality. In some examples, the anti-icing and de-icing functionality can provide heating to all areas of the aircraft susceptible to icing, such as the wings, pylons, nacelles, and tail. In some examples, heat transfer structures may be provided adjacent to the wing leading edges and / or wingtips. In some examples, the heat transfer structures may be positioned below the wing leading edges or may wrap around the wing leading edges. In some examples, the aircraft may be an aircraft including electrically powered propulsion, such as an eVTOL aircraft.

[0013] Certain aspects of this disclosure relate to an ice protection system for an electrically powered aircraft that transfers heat from electronic components such as an electric propulsion motor, inverter, and battery to areas prone to icing, such as the wings, pylons, tail, and nacelles. In some examples, a control device may manage, proportion, redistribute, and / or divide the flow of heat transfer fluid (e.g., coolant) to heat transfer structures of the ice protection systems in accordance with system requirements. In some examples, the heat transfer structures may include skin heat exchangers that direct heat to the aircraft skin.In some examples, heat transfer structures may include primary and secondary flow paths, with the primary flow path adapted for anti-icing and the secondary flow path adapted for de-icing. Anti-icing systems are designed to prevent ice formation, and de-icing systems are designed to promote the melting of ice that has begun to form. For example, a de-icing system may be configured to melt ice at the interface between the ice and the aircraft to facilitate ice melting (e.g., to facilitate ice purging).

[0014] In some examples, the control of the heat transfer fluid flow through the primary and secondary flow paths can be coordinated to provide a heat flux level that corresponds to the environmental conditions encountered. In some examples, the primary flow path can provide a heat flux up to a first level (e.g., to provide an anti-icing function) and the secondary flow path can provide additional heat flux added to the heat flux provided by the primary flow path (for example, to provide a defrosting function) in order to provide a second-level heat flux higher than the first level under conditions where the first-level heat flux is insufficient to prevent icing. In some examples, the flow through the primary and secondary flow paths is controlled separately so that different flow rates can be provided through the primary and secondary flow paths and / or different flow control protocols can be used for the primary flow path compared to the secondary flow path. In some examples, the primary and secondary flow paths can be controlled independently.In some examples, the primary flow path may be used more frequently or for longer periods than the secondary flow path. In some examples, the primary and / or secondary flow paths may be operated continuously or intermittently during a flight. In some examples, the flow rate through the primary and / or secondary flow paths may be modified based on environmental conditions. In some examples, the duration of a duty cycle versus a rest cycle of the primary and / or secondary flow paths may be modified based on environmental conditions.In some examples, the heat transfer fluid is normally routed through the primary flow path during a flight, and is routed through the secondary flow path (e.g., intermittently; continuously) during a flight based on environmental conditions. In other examples, heat transfer fluid is routed through the primary flow path (e.g., continuously, intermittently, etc.) during a flight, and is routed through the secondary flow path only when environmental conditions dictate that de-icing is advisable. In some examples, the primary and secondary flow paths can be switched on and off independently as needed to perform their heating function while minimizing power consumption.In some examples, the primary and secondary flow paths define different heating zones, with the different heating zones capable of accommodating different flow rates (e.g., variable flow rates) within the different heating zones. In some examples, the primary and secondary flow paths define different heating zones, and flow through the different heating zones can be controlled separately. to provide separately controlled heat flows at the level of the different heating zones.

[0015] In some examples, the heat transfer structure may have a composite construction including at least a first part constructed from a lower density material (e.g., non-metallic) and a second part constructed from a more thermally conductive material (e.g., metallic). The composite construction of the heat transfer structure can help to optimize / reduce the weight of the heat transfer structure. In some examples, the thermally conductive material may be constructed in the form of a relatively thin heat sink having a sheet-like configuration that extends along the flow paths of the heat transfer structure and improves the overall heat transfer efficiency of the heat transfer structure.The heat sink can be attached adjacent to an inner surface of an aircraft skin so that heat is distributed through the skin to aid anti-icing or de-icing at an outer surface of the skin. While a variety of configurations can be implemented, in one example, the primary flow path can extend along a section of a structure that is to be kept ice-free (e.g., along a wing leading edge extending the length of the wing) and can also exhibit a chord-direction distribution at regular intervals (e.g., can extend along a wing width that spans between a wing leading edge and a wing trailing edge).The secondary flow path can help melt local ice and can be adapted to heat aircraft surfaces not served by the primary flow path and / or can provide additional heat to areas adjacent to the primary flow path. In some examples, the primary and / or secondary flow paths may wrap around a leading edge of an aircraft wing and extend along the wing's width at the upper and lower edges of the wing. In some examples, the primary and secondary flow paths alternate in an orientation that extends along the wing's length / span, with the primary and secondary flow paths themselves extending in an orientation along the wing's width.In some examples, an electric heating system may be provided to supplement the heating provided by the primary and secondary flow paths. In some examples, the primary flow path may include at least one portion extending along a leading edge of a wing (e.g., in an orientation extending from a base to a tip of the wing) and / or may include at least one portion extending across a wing width (e.g., in an orientation extending from a leading edge to a trailing edge of the wing). the wing). In some examples, the secondary flow path may include at least one portion extending along a leading edge of a wing (e.g., in an orientation extending from a wing base to a wing tip) and / or may include at least one portion extending across a wing span (e.g., in an orientation extending from a wing leading edge to a wing trailing edge). In some examples, the primary and secondary flow paths may each include at least one portion extending along a wing leading edge and / or may each include at least one portion extending across a wing span.

[0016] Certain aspects of this disclosure relate to an ice protection system that uses heat generated by the electric motor and / or inverter of an eVTOL aircraft by directing a heated heat transfer fluid (e.g., a glycol-based fluid) exiting the motor and / or inverter to a heat exchanger (e.g., a skin heat exchanger) located in a region of the aircraft prone to icing (e.g., the wings). The electric motor may power a propulsion structure of the aircraft and may be referred to as an electric propulsion motor. In some examples, the ice protection system may also optionally use heat generated by a battery powering the electric propulsion motor by directing the heat transfer fluid heated by the battery (e.g., flowing through a battery cooling loop) to the heat exchanger.In some examples, the heat exchanger incorporates a combination of primary and secondary flow paths, providing an energy-efficient solution by combining the benefits of de-icing and anti-icing. In some examples, an intelligent architecture incorporating a system control device, a fluid transport system, and a skin heat exchanger helps reduce overall weight and additional power requirements without compromising flight time. It also reduces the load on thermal management systems associated with electronic components such as the propulsion motor / inverter and battery. In some examples, a heat diffusion arrangement can improve overall heat transfer and reduce the overall weight of the design architecture.In some examples, the system can effectively reduce battery power consumption for defrosting and anti-icing, and can reduce weight by eliminating electric heating elements or minimizing their size (e.g., resistive heating elements). In some examples, defrosting and / or anti-icing can be achieved by reallocating heat generated by a propulsion motor / inverter and / or a battery using a smart architecture that includes an intelligent control device and an arrangement of... fluid transport and a heat exchanger such as a skin-type heat exchanger.

[0017] Referring to [Fig. 1], the ice protection system 20 is incorporated as part of an aircraft 21 such as an electrically powered aircraft (e.g., an eVTOL aircraft). The ice protection system 20 enables the aircraft 21 to operate in cold weather conditions. The aircraft 21 includes an inverter 22 driving an electric motor 24 to drive an aircraft structure such as a propulsion structure (e.g., a propeller). The electric motor 24 can be powered by a battery 26. The aircraft 21 includes a first cooling loop 28 for cooling the electric motor 24 and the inverter 22, and a second cooling loop 34 cooling the battery 26.The first cooling loop 28 includes a pump 32 for pumping a heat transfer fluid (e.g., a coolant such as a glycol-based fluid) through the electric motor 24, the inverter 22, and a thermal management system 33. The thermal management system 33 may include one or more air-cooled heat exchangers for transferring heat from the heat transfer fluid to the ambient air. The heat transfer fluid cooled by the thermal management system 33 can be conveyed to a reservoir 36 in fluidic communication with an inlet of the pump 32. The thermal management system 33 can be sized taking into account the fluid cooling capacity of the ice protection system 20, thus allowing the thermal management system 33 to be smaller (e.g., lighter) than if the ice protection system were not present.The second cooling loop 34 includes a pump 44 pumping heat transfer fluid through the coil 26 and through a cooler 46 (for example, an evaporator) to cool the heat transfer fluid. The heat transfer fluid exiting the cooler 46 can be routed to a reservoir 51 which is in fluidic communication with an inlet of the pump 44. The cooler 46 can be part of a refrigeration loop 48 including a compressor 45, a condenser 47 (for example, an air-cooled condenser) and a thermal expansion valve 49.

[0018] The heat transfer fluid in each of the first and second cooling loops 28, 34 may have different average temperatures. For example, the heat transfer fluid in the first cooling loop 28 may have a higher temperature than the heat transfer fluid in the second cooling loop 34. Therefore, for some applications, it is desirable to keep the first and second cooling loops 28, 34 separate from each other with separate reservoirs 36, 51 rather than a shared reservoir. In other examples, the cooling loops 28, 34 could be merged (for example, could share a common tank). In some examples, a fluid from one of the cooling loops 28, 34 can be used to direct heat to one or more flow paths of a heat exchanger arrangement in an anti-icing zone, and a fluid from the other of the cooling loops 28, 34 can be used to direct heat to one or more flow paths of a heat exchanger arrangement in a defrosting zone.In some examples, fluid from one of the cooling loops 28, 34 can be used to direct heat to one or more flow paths of heat exchanger arrangements in both the anti-icing and de-icing zones, and the other of the cooling loops 28, 34 is available as a backup to direct heat to one or more flow paths of heat exchanger arrangements in both the anti-icing and de-icing zones. In other examples, based on monitored conditions (e.g., aircraft operating conditions, environmental conditions, engine 24 / inverter 22 and / or cooling loop 28 operating conditions, battery 26 and / or cooling loop 34 operating conditions, etc.).), a control device 100 can select which of the cooling loops 28, 34 supplies heat to the anti-icing zone and which of the cooling loops 28, 34 supplies heat to the defrosting zone. .

[0019] The ice protection system 20 includes a heat transfer structure 50 for heating a region of the aircraft 21 subject to icing (e.g., the wings, pylons, nacelles, and tail). The heat transfer structure 50 shown in Figures 2 and 3 is configured to heat a wing 200 of the aircraft 21 (e.g., specifically at a location adjacent to a leading edge 202 of the wing 200). The heat transfer structure 50 includes a primary flow path 52 (e.g., one or more passages or an arrangement of passages that function as a heat exchanger for a primary heating area such as an anti-icing area) and a secondary flow path 54 (e.g., one or more passages or an arrangement of passages that function as a heat exchanger for a secondary heating area such as a de-icing area). As shown in the [Fig.3], which represents part of an example of a heat transfer structure, the heat transfer structure 50 may include an arrangement of fluid passages defined by a structure such as a collector 60 with fluid passages 52a, 52b corresponding to the primary flow path 52 and other fluid passages 54a corresponding to the secondary flow path 54. The wing has a wingspan dimension S which extends along a length of the wing and a width dimension W which extends from a leading edge to a leading edge. wing leakage. The primary flow path 52 includes at least one passage 52a configured to extend along the length of the wing 200 (i.e., along the wingspan dimension) as at the leading edge 202 of the wing 200 when the heat transfer structure 50 is integrated into the wing 200. The primary flow path 52 also includes sets of secondary passages 52b that extend along the width dimension W of the wing when the heat transfer structure 50 is integrated into the wing. The secondary flow path 54 includes sets of passages 54a that extend along the width dimension W of the wing when the heat transfer structure 50 is integrated into the wing 200.As shown in Figures 2 and 3, the flow path assemblies 52b, 54a are configured to be mutually positioned alternately along the wingspan dimension S of the wing 200 when the heat transfer structure 50 is integrated into the wing 200. The flow paths 52b, 54a are configured to wrap around the leading edge 202 of the wing 200 and include portions 203 (see [Fig. 3]) adapted to extend along an upper side of the wing 200, and portions 205 adapted to extend along a lower side of the wing 200 when the heat transfer structure 50 is integrated into the wing 200. It should be noted that the flow paths shown are provided by way of example, and that other flow path configurations may also be used to provide heating zonal aircraft component system for anti-icing and de-icing.Furthermore, the flow paths shown are schematic, and it should be noted that such flow paths / passages are used in combination with additional supply and return flow paths to allow the heat transfer fluid to flow through the various flow passages.

[0020] The ice protection system 20 also includes a fluid transport arrangement 80 for transporting the heat transfer fluid heated by the inverter 22 and the electric motor 24 (for example, the heat transfer fluid from the first cooling loop 28) to the heat transfer structure 50. The fluid transport arrangement 80 can also be configured to transport a heat transfer fluid heated by the battery 26 (for example, a heat transfer fluid from the second cooling loop 34) to the heat transfer structure 50.The fluid transport arrangement 80 includes a valve arrangement comprising a first valve structure 82 corresponding to the first cooling loop 28, a second valve structure 84 corresponding to the second cooling loop 34 and a third valve structure 86 to control the flow of fluid to and from the heat transfer structure 50. The valve structures may each include a valve such as a multi-position valve, a plurality of valves, a . Valve manifolds, or similar structures, are used to control the flow of the heat transfer fluid. In some examples, the valve structures may include proportional flow valves adapted to control a flow rate supplied through the proportional flow valves. In some examples, the valve structures can divert the flow to different flow paths and provide different flow rates as indicated by the control device 100.

[0021] The first valve structure 82 controls the flow of the heat transfer fluid through the supply and return lines 150, 151 between the first cooling loop 28 and the third valve structure 86. When heat transfer fluid is not intended to be directed to the heat transfer structure 50 from the first cooling loop 28, the first valve structure 82 can close the supply and return lines 150, 151 so that all the flow passes from the inverter 22 through the first valve structure 82 to the liquid-air heat exchanger 33.When heat transfer fluid from the first cooling loop 28 is intended to be directed to the heat transfer structure 50, the first valve structure 82 opens the supply and return lines 150, 151 so that part of the heat transfer fluid flowing through the first valve structure 82 from the inverter 22 to the liquid-air heat exchanger is diverted to the third valve structure 86 and the heat transfer structure 50 through the supply line 150. The heat transfer fluid returning from the heat transfer structure 50 through the third valve structure 86 and the return line 151 is directed from the first valve structure 82 to the liquid-air heat exchanger 33.

[0022] The second valve structure 84 controls a flow of heat transfer fluid through the supply and return lines 152, 153 between the second cooling loop 34 and the third valve structure 86. When heat transfer fluid is not intended to be directed to the heat transfer structure 50 from the second cooling loop 34, the second valve structure 84 can close the supply and return lines 152, 153 so that all the flow passes from the coil 26 through the second valve structure 84 to the evaporator 46.When heat transfer fluid from the second cooling loop 34 is intended to be directed to the heat transfer structure 50, the second valve structure 84 opens the supply and return lines 152, 153 so that some of the heat transfer fluid flowing through the second valve structure 84 from the coil 26 to the evaporator 46 is diverted to the third valve structure 86 and the heat transfer structure 50 through the supply line 152. The heat transfer fluid returning from . The heat transfer structure 50 through the third valve structure 86 and the return line 153 is directed from the second valve structure 84 to the evaporator 46.

[0023] The third valve structure 86 controls the flow of heat transfer fluid to and from the heat transfer structure 50. The third valve structure 86 can stop the flow to and from the primary flow path 52 and / or the secondary flow path 54. The third valve structure 86 can provide a flow to and from the primary flow path 52 and / or the secondary flow path 54.If it is planned that the flow is directed through one or both of the primary and secondary flow paths 52, 54, the control device 100 can use the third valve structure 86 to select which of the first and second cooling loops 28, 34 circulates heat transfer fluid through the primary flow path 52 and which of the first and second cooling loops 28, 34 circulates heat transfer fluid through the secondary flow path 54.

[0024] The ice protection system 20 further includes a control device 100 (for example, an electronic control device including one or more processors and memory) which interfaces with the valve arrangement to control the flow of the heat transfer fluid to and through the heat transfer structure 50. The control device 100 is adapted to control the valve arrangement such that during a flight, the primary flow path 52 is adapted to provide an anti-icing function and the secondary flow path 54 is adapted to provide a de-icing function. In addition, under certain conditions, the flow can be directed from the first or second cooling loop 28, 34 to provide additional cooling to the cooling loops regardless of whether environmental conditions warrant anti-icing or de-icing.The control device 100 and the valve arrangement allow the flows through the primary flow path 52 and the secondary flow path 54 to be controlled differently from each other; however, in some examples, they can be coordinated to achieve a desired heat flow. For example, the primary and secondary flow paths 52 and 54 can be operated at different times, at different flow rates, for different durations, for different cycle times, and from different heat transfer fluid sources (e.g., the first cooling loop 28 or the second cooling loop 34). In some examples, the primary flow path 52 and / or the secondary flow path 54 can be switched off during a flight, run continuously during a flight, or switched on. and switched off during a flight, or operate at certain times or stages of the flight. The primary and secondary flow paths 52, 54 can be operated separately or independently of each other. The primary and secondary flow paths can be operated at different flow rates or at different time periods. The primary flow path 52 and the secondary flow path 54 can be operated to provide different levels of heat flux over a given time period. The primary flow path 52 can be actuated to provide up to a first level of heat flux when actuated alone, and the secondary flow path 54 can provide additional heating such that the primary and secondary flow paths 52, 54 together can provide a second level of heat flux higher than the first level of heat flux.

[0025] During a flight, in an optional example, the control device 100 can control the valve arrangement so that the heat transfer fluid flows continuously through the primary flow path 52, and the flow of the heat transfer fluid through the secondary flow path 54 is switched on and off intermittently. In such an example, a duration for which the flow through the second flow path 54 is switched on and a duration for which the flow through the second flow path 54 is switched off is modified by the control device 100 based on environmental data entered into the control device 100 (for example, from an input 102 such as one or more sensors, another control device, a meteorological data source, etc.).Examples of environmental data might include ambient air temperature, air velocity, humidity, condensation, etc. During a flight, the control device 100 can direct flow to the primary flow path 52 to provide relatively constant heating to prevent ice formation and can direct flow to the secondary flow path 54 to provide intermittent heating to promote ice melting. During a flight, the control device can direct flow to the primary flow path 52 to provide relatively constant heating to prevent ice formation and can cycle the flow over and off the secondary flow path 54 to promote ice melting.The activation and deactivation cycle of the flow through the secondary flow path 54 can be modified by the control device 100 based on the input environmental conditions. It should be noted that other control strategies can also be used, such as cyclic operation of the primary and secondary flow paths 52, 54; continuous operation of the primary and / or secondary flow paths 52, 54. 54 and optionally the variation of the flow rate at one of the flow paths 52, 54 or both to vary the heat flux; or other control strategies.

[0026] With reference to Figures 3 and 4, the heat transfer structure 50 (for example, a heat exchanger) has a composite construction including the manifold 60 defining flow passages corresponding to the primary and secondary flow paths 52, 54. The manifold 60 includes a relatively low-conductivity molded structure 120 of lower density and a relatively high-conductivity heat transfer sheet 122 of higher density which cooperate to define the flow passages of the heat transfer structure 50. The heat transfer sheet 122 is adapted to be fixed adjacent to an inner surface of an aircraft skin 124 to distribute heat to the region of the aircraft prone to icing.In one example, the relatively low-conductivity, lower-density molded structure is non-metallic (e.g., molded plastic) and the heat transfer foil is metallic (e.g., copper, aluminum, alloys, a thermally conductive composite).

[0027] In certain examples, an optional resistive electric heating structure can be used in combination with the heat transfer structure 50 to heat the area of ​​the aircraft prone to ice formation. The resistive electric heating structure can be powered by an electric battery and may include resistive heating elements that generate heat when an electric current is directed through them. The control device 100 can activate the resistive heating structure when environmental conditions are such that the heat transfer structure 50 is unable to provide sufficient heating. The control device can generate an icing value representative of the ice formation rate based on detected environmental factors such as temperature, humidity, condensation, and ambient temperature.Based on the temperature of the heat transfer fluid, the control device can calculate whether the heat transfer structure is capable of providing sufficient heating given the frost value. If not, the control device 100 can activate the resistive electric heating structure to provide additional heating.

[0028] Figure 5 is a flowchart describing an example of control logic used by the control device 100 to control the operation of the ice protection system 20. In step 400, the control device 100 accesses environmental data such as air temperature, air velocity, humidity (for example, from temperature sensors, velocity sensors, and humidity sensors) and determines an icing value. representative of a critical ice thickness. The control device can also access data from ice detection sensors (e.g., vibration or optical) to further assess the level of ice development. Then, in step 402, based on environmental data and data from the ice detection sensors, the control device 100 determines a control strategy to achieve the required heat flow in the primary and secondary flow paths 52, 54 to provide protection against ice buildup through an anti-icing and defrosting function. In step 404, the control device 100 can determine the required flow rates and / or duty cycles of the heat transfer fluid through the primary and secondary flow paths 52, 54 to achieve the heat flow required for appropriate protection against ice buildup.Ice sensors can provide feedback on system efficiency, and the control device can modify the control strategy based on feedback from the ice sensors. The pump speeds of pump 32 of the first cooling loop 28 and / or pump 44 of the second cooling loop 34 can be monitored and adjusted to ensure proper cooling of the equipment (e.g., battery and motor / inverter cooling) through cooling provided by a combination of heat transfer at the heat transfer structure 50 (e.g., at the primary and secondary flow paths), heat transfer at the liquid-air heat exchanger 33, and heat transfer at the evaporator 46 (see step 406).In step 408, the system can determine, based on a sensor input, whether the heat transfer structure can provide sufficient heat flux to achieve acceptable levels of anti-icing and defrosting. If sufficient heat flux is provided, the process proceeds to step 410 where the system status is monitored / checked, and then returns to step 400. If insufficient heat flux is provided, the control device 100 can activate additional heating, such as from a resistive heating device (step 412). Upon activation of the heating element, the system process then proceeds to steps 410 and returns to step 400 to repeat the processing steps described above.

[0029] Aspects of this disclosure relate to systems that allow low-quality heat (e.g., waste heat from cooling electrical components / electro-equipment of an aircraft such as an electrically powered and propelled aircraft (e.g., an eVTOL aircraft)) to be used efficiently to provide de-icing and / or anti-icing functionality. In one example, the heat transfer fluid carrying the low-quality heat typically has a temperature below 110 degrees Celsius. In some examples, low-quality heat may be waste heat from an electric motor (e.g., an electric motor used to drive aircraft propulsion, an electric motor operating as an actuator, an electric motor driving hydraulic components such as pumps, etc.), an inverter controlling the operation of an electric motor such as some of the electric propulsion motors, a battery system used to power an electrical component of the aircraft such as an electric propulsion motor, an electrical power system, an electrical control system, or other electrical systems / electrical components / electrical equipment.

[0030] It should be noted that the inverter can control the rotational speed and / or the torque of the electric propulsion motor. The electric propulsion motor can be an alternating current (AC) electric motor, and the inverter can control the supply frequency provided to the electric propulsion motor to control its rotational speed.

[0031] It should be noted that additional valves, check valves, Pumps, tanks, and other structures, in addition to those specifically shown, may be provided to ensure proper flow and circulation within the system. The pumps may be variable-flow pumps, where the outlet flow rate can be changed by varying the pump's rotational speed or displacement. The pumps may be driven by electric motors.

[0032] Various modifications and alterations to this disclosure will be apparent to a person skilled in the art without departing from the scope and spirit of this disclosure, and it should be understood that the scope of this disclosure should not be unduly limited to the illustrative embodiments stated herein.

[0033] Aspect 1. Ice protection system for use with an aircraft including an electric motor for driving an aircraft propulsion structure, the ice protection system comprising: a heat transfer structure for heating a region of the aircraft prone to icing, the heat transfer structure comprising a primary flow path and a secondary flow path; a fluid transport arrangement for circulating a heat transfer fluid heated by waste heat from an electrical component of the aircraft through the heat transfer structure, the fluid transport arrangement comprising a valve arrangement; and a control device that interfaces with the valve arrangement to control the flow of the heat transfer fluid to and through the structure of heat transfer, in which the control device is adapted to control the arrangement of valves such that during a flight, the primary flow path is adapted to provide an anti-icing function and the secondary flow path is adapted to provide a de-icing function.

[0034] Aspect 2. The ice protection system according to aspect 1, wherein the electric motor is controlled by an inverter and powered by a battery, wherein the inverter and the electric motor are cooled by a first cooling loop and the battery is cooled by a second cooling loop, and wherein the heat lost to heat the heat transfer fluid is supplied from the first or second cooling loop.

[0035] Aspect 3. Ice protection system according to aspect 1 or 2, wherein the valve arrangement is configured to allow flows through the primary and secondary flow paths to be controlled separately.

[0036] Aspect 4. Ice protection system according to any one of aspects 1 to 3, wherein the control device independently controls the flows through the primary flow path and the secondary flow path.

[0037] Aspect 5. Ice protection system according to any one of aspects 1 to 4, wherein during a flight, the control device actuates the valve arrangement such that the primary flow path provides a first level of heat flux to provide the anti-icing function, and the secondary flow path complements the primary flow path with an additional heat flux to provide a de-icing function.

[0038] Aspect 6. Ice protection system according to any one of aspects 1 to 5, wherein the control device actuates the primary flow path to provide a different heat flux compared to the secondary flow path.

[0039] Aspect 7. Ice protection system according to any one of aspects 1 to 6, in during a flight the control device directs flow to the primary flow path to provide relatively constant heating to prevent ice formation, and directs flow to the secondary flow path to provide intermittent heating to promote ice melting.

[0040] Aspect 8. Ice protection system according to any one of aspects 1 to 7, further comprising a resistive electric heating structure used in combination with the heat transfer structure to heat the area.

[0041] Aspect 9. Ice protection system according to aspect 2, in which the control device selects between the first and second cooling loops to supply the heat transfer fluid to the heat transfer structure.

[0042] Aspect 10. Ice protection system according to aspect 2 or 9, wherein the heat transfer fluid is conveyed to the heat transfer structure from the first cooling loop, wherein the first cooling loop includes an air-cooled heat exchanger, and wherein the air-cooled heat exchanger is sized taking into account a cooling capacity of the heat transfer structure.

[0043] Aspect 11. Ice protection system according to any one of aspects 2, 9 and 10, wherein the heat transfer fluid is conveyed to the heat transfer structure from the second cooling loop, and wherein the second cooling loop is cooled by an evaporator from a refrigeration loop.

[0044] Aspect 12. Ice protection system according to any one of aspects 1 to 11, wherein the heat transfer structure has a composite construction including a manifold defining flow passages corresponding to the primary and secondary flow paths, wherein the manifold includes a relatively low conductivity molded structure of lower density and a relatively high conductivity heat transfer sheet of higher density which cooperate to define the flow passages, and wherein the heat transfer sheet is adapted to be fixed adjacent to an internal surface of an aircraft skin to distribute heat to the region of the aircraft prone to icing.

[0045] Aspect 13. Ice protection system according to aspect 12, wherein the relatively low conductivity molded lower density structure is non-metallic and the heat transfer foil is metallic.

[0046] Aspect 14. Ice protection system according to any one of aspects 1 to 13, wherein the aircraft region subject to icing is a wing, wherein the wing has a wingspan dimension extending along a wing length and a width dimension extending from a leading edge to a trailing edge of the wing, wherein the primary flow path includes a first passage extending along the wing length at the wing's leading edge, wherein the primary flow path includes sets of second passages extending along the wing's width dimension, wherein the secondary flow path includes sets of third passages extending along the wing's width dimension, and wherein the sets of second and third passages are positioned alternately with respect to each other along the wingspan dimension. the wing.

[0047] Aspect 15. Ice protection system according to aspect 14, in which the second and third pass assemblies wrap around the leading edge of the wing and include parts that extend along the upper and lower sides of the wing.

[0048] Aspect 16. De-icing or anti-icing device for an aircraft component, comprising: a heat transfer structure having a composite construction including a manifold defining flow passages corresponding to primary and secondary flow paths, wherein the manifold includes a relatively low-conductivity, lower-density molded structure, and

[0049] a relatively highly conductive heat transfer sheet of higher density which cooperates to define flow passages, and wherein the heat transfer sheet is adapted to be fixed in a location adjacent to an inner surface of an aircraft skin to distribute heat to a region of the aircraft prone to icing.

[0050] Aspect 17. Device according to aspect 16, in which the relatively low conductivity molded lower density structure is non-metallic and the heat transfer foil is metallic.

Claims

Demands

1. Ice protection system for use with an aircraft including an electric motor for driving an aircraft propulsion structure, the ice protection system comprising: a heat transfer structure for heating a region of the aircraft prone to icing, the heat transfer structure comprising a primary flow path and a secondary flow path; a fluid transport arrangement for circulating a heat transfer fluid heated by waste heat from an electrical component of the aircraft through the heat transfer structure, the fluid transport arrangement comprising a valve arrangement;and a control device which interfaces with the valve arrangement to control the flow of the heat transfer fluid to and through the heat transfer structure, wherein the control device is adapted to control the valve arrangement such that during a flight, the primary flow path is adapted to provide an anti-icing function and the secondary flow path is adapted to provide a de-icing function.

2. The ice protection system according to claim 1, wherein the electric motor is controlled by an inverter and powered by a battery, wherein the inverter and the electric motor are cooled by a first cooling loop and the battery is cooled by a second cooling loop, and wherein the heat lost to heat the heat transfer fluid is supplied from the first or second cooling loop.

3. Ice protection system according to claim 1 or 2, wherein the valve arrangement is configured to permit flows through the primary and secondary flow paths to be controlled separately.

4. An ice protection system according to any one of claims 1 to 3, wherein the control device controls independently the flows through the primary flow path and the secondary flow path.

5. Ice protection system according to any one of claims 1 to 4, wherein during a flight, the control device actuates the valve arrangement such that the primary flow path provides a first level of heat flux to provide the anti-icing function, and the secondary flow path complements the primary flow path with an additional heat flux to provide a de-icing function.

6. Ice protection system according to any one of claims 1 to 5, wherein the control device actuates the primary flow path to provide a different heat flux compared to the secondary flow path.

7. Ice protection system according to any one of claims 1 to 6, wherein during a flight, the control device directs flow to the primary flow path to provide relatively constant heating to prevent ice formation, and directs flow to the secondary flow path to provide intermittent heating to promote ice melting.

8. Ice protection system according to any one of claims 1 to 7, further comprising a resistive electric heating structure used in combination with the heat transfer structure to heat the area.

9. Ice protection system according to claim 2, wherein the control device selects between the first and second cooling loops to supply the heat transfer fluid to the heat transfer structure.

10. Ice protection system according to claim 2 or 9, wherein the heat transfer fluid is routed to the heat transfer structure from the first cooling loop, wherein the first cooling loop includes an air-cooled heat exchanger, and wherein the air-cooled heat exchanger is sized taking into account a cooling capacity of the heat transfer structure.

11. Ice protection system according to any one of claims 2, 9 and 10, wherein the heat transfer fluid is conveyed to the heat transfer structure from the second cooling loop, and in which the second cooling loop is cooled by an evaporator of a refrigeration loop.

12. An ice protection system according to any one of claims 1 to 11, wherein the heat transfer structure has a composite construction including a manifold defining flow passages corresponding to the primary and secondary flow paths, wherein the manifold includes a relatively low-conductivity molded structure of lower density and a relatively high-conductivity heat transfer sheet of higher density that cooperate to define the flow passages, and wherein the heat transfer sheet is adapted to be fixed adjacent to an internal surface of an aircraft skin to distribute heat to the region of the aircraft prone to icing.

13. Ice protection system according to claim 12, wherein the relatively low conductivity molded lower density structure is non-metallic and the heat transfer foil is metallic.

14. An ice protection system according to any one of claims 1 to 13, wherein the region of the aircraft subject to icing is a wing, wherein the wing has a wingspan dimension extending along a length of the wing and a width dimension extending from a leading edge to a trailing edge of the wing, wherein the primary flow path includes a first passage extending along the length of the wing at the leading edge of the wing, wherein the primary flow path includes sets of second passages extending along the width dimension of the wing, wherein the secondary flow path includes sets of third passages extending along the width dimension of the wing, and wherein the sets of second and third passages are positioned alternately with respect to each other along the wingspan dimension of the wing.

15. Ice protection system according to claim 14, wherein the second and third passage assemblies wind around the leading edge of the wing and include parts that extend along the upper and lower sides of the wing.

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