COOLING ARCHITECTURE FOR A CRYOGENIC AND SUPERCONDUCTIVE PARALLEL-LINE POWERTRAIN ENGINE

Abstract

Cooling architecture for a cryogenic and superconducting propulsion unit with parallel lines. The present invention relates to a cryogenic and superconducting propulsion unit comprising at least one superconducting electric motor (12) and a cooling architecture including a heat exchanger (36) configured to exchange heat between a first fluid and a second fluid, the second fluid following at least one cooling loop (102) of components (12, 14, 20, 24) starting with the motor, the cooling loop (102) comprising two parallel cooling lines between the motor (12) and the exchanger (36): a cooling line (102a) of control units; a cooling line (102b) in series with the DCc cables (20) and current leads (24); the two lines (102a) and (102b) originating from the motor (12) and joining into a single line to the exchanger (36). Figure from the summary: Figure 2

Description

Title of the invention: COOLING ARCHITECTURE FOR A CRYOGENIC AND SUPERCONDUCTIVE PARALLEL-LINE POWERTRAIN ASSEMBLY

[0001] The present invention relates to a cryogenic and superconducting powertrain having a cooling architecture.

[0002] Current cooling architectures for a cryogenic and superconducting powertrain rely on industrial cryo-coolers specifically designed for ground-based applications. Cryo-coolers designed for ground-based applications cannot be used for aeronautical applications because they lack the necessary cooling capacity. Furthermore, there are also significant concerns related to the weight and efficiency of these cryogenic coolers intended for aeronautical applications.

[0003] In contrast, the liquid hydrogen (LH2) available on board can be used to cool the powertrain components. However, for safety reasons, in aeronautical applications, liquid hydrogen is not intended for direct use (i.e., for the direct cooling of electrical components). Furthermore, the amount of liquid hydrogen stored in a tank for a fuel cell system for a given phase of flight is limited and, generally, driven by the needs of the fuel cell itself.

[0004] An optimization of the cooling architecture is therefore necessary in order to optimize the consumption of liquid hydrogen and to meet the cooling needs of the powertrain with the flow of liquid hydrogen available in a given phase of flight.

[0005] A current cryogenic and superconducting powertrain comprises: - A superconducting motor; - A motor control unit (MCU), designed to control the functional aspects of the superconducting motor; - A direct current (DC) line; - Main current leads (Ld) to the fuel cells, and - A DC / DC converter designed to adapt the voltage levels between the DC line and the main current leads.

[0006] The various components of the cryogenic and superconducting powertrain have different cooling requirements, both in terms of maximum permissible temperature and maximum permissible temperature gradient across the components themselves. Furthermore, the performance and efficiency of the component itself depend on the temperature.

[0007] The table below summarizes the maximum allowable temperature and the maximum allowable temperature gradient of the components of the cryogenic and superconducting powertrain.

[0008] [Tables 1] Component of the cryogenic and superconducting Esotnpropuitettr group Maximum permissible temperature (Imai) Maximum permissible temperature gradient Superconducting motor 40K Motor control unit (MCU) 12QK 20K DC line 75K DC / DC converter 140K 20K Main current tracks 15SK

[0009] According to this table, if the superconducting motor is exposed to a temperature above 40 K (its Tmax), there is a risk of quenching (sudden loss of the superconducting state) within the superconducting motor. Furthermore, the efficiency of the superconducting motor is temperature-dependent: the superconducting motor has better efficiency at temperatures below its threshold temperature Tmax (i.e., below 40 K).

[0010] The maximum permissible temperature gradient for the MCU control unit (here 20K) must not be exceeded to ensure its proper operation. Furthermore, the efficiency of the MCU unit is temperature-dependent: the MCU unit has better efficiency at a temperature below its threshold temperature Tmax (i.e., below 120K).

[0011] If the DC line is exposed to a temperature above its threshold temperature 75K (its Tmax), a risk of quenching appears within the DC line.

[0012] The maximum permissible temperature gradient of the DC / DC converter (here 20K) must not be exceeded to ensure proper operation of the DC / DC converter. Furthermore, the efficiency of the DC / DC converter is temperature-dependent: the DC / DC converter has better efficiency at a temperature below its Tmax (i.e., below 140K).

[0013] The efficiency of the main current supplies to the fuel cell depends on the temperature: the main current supplies have a better efficiency at a temperature below their threshold temperature Tmax (i.e. below 150K).

[0014] Consequently, not all components of the cryogenic powertrain have the same cooling requirements and therefore do not need to be cooled to the same temperature, since each component does not have the same maximum allowable temperature.

[0015] Thus, there is a need for a process and system to manage the cooling temperature of each component of the cryogenic and superconducting powertrain.

[0016] To this end, a cryogenic and superconducting powertrain is proposed comprising: - at least one superconducting electric motor (12), - at least one motor control unit (14) configured to control the operating aspects of the superconducting electric motor (12), - at least one superconducting distribution and protection device (20), called cables (20), - at least one main current supply (24) to the fuel cell (22), - a cooling architecture (30) comprising: - a tank of a first fluid (32) for storing this fluid at cryogenic temperature, - a tank (35) of a second fluid;- a heat exchanger (36) configured to exchange heat between the first fluid and a second fluid, the second fluid following at least one cooling loop (102) of components (12, 14, 20, 24) starting with the motor, the cooling loop (102) comprising two parallel cooling lines between the motor (12) and the exchanger (36): - a cooling line (102a) for the control units; - a cooling line (102b) in series with the DCc cables (20) and power supplies (24); the two lines (102a) and (102b) originating from the motor (12) and joining into a single line to the exchanger (36).

[0017] The invention provides at least one of the following optional features, taken individually or in combination.

[0018] The first fluid comprises liquid hydrogen (LH2) and the second fluid comprises gaseous helium (GHe).

[0019] The cooling architecture includes a primary heating loop for the first fluid so as to heat it for use by a fuel cell and a secondary cooling loop for the second fluid so as to cool it to cool all of said components.

[0020] The secondary cooling loop is arranged and configured to cool components of the cryogenic and superconducting powertrain.

[0021] The secondary cooling loop is cooled by the flow of the second fluid, and in return heats the first fluid which enters the fuel cell.

[0022] The powertrain further comprises: - at least one cryogenic recirculation fan for recirculating the second fluid in the components cryogenic and superconducting powertrain fluids in a fully closed loop, and - cryogenic insulated lines to carry cryogenic fluid to the electrical components of the cryogenic and superconducting powertrain.

[0023] The cooling architecture includes an additional cooling line intended to conduct the flow of a second fluid upstream of the exchanger, i.e. not cooled by it, towards the inlet of the MCUs control units.

[0024] The cooling architecture includes an additional local cooling line intended to conduct the flow of second fluid downstream of the control units to the inlet of said control units.

[0025] The cooling architecture includes a second fan to drive the flow downstream of the control units towards their inlet.

[0026] The present invention also relates to an aircraft comprising a powerplant having at least one of the following optional features, taken individually or in combination, presented above, in which the tanks and the heat exchanger are located in the fuselage of the aircraft and components of the cooling architecture are located in a pod in a nacelle.

[0027] Other objects, features and advantages will become apparent from the following description of the invention, given by way of non-limiting example only, with reference to the accompanying drawings in which: [Fig. 1] illustrates in simplified perspective a cooling architecture for a cryogenic and superconducting powertrain operating at cryogenic temperature according to one embodiment of the invention; [Fig. 2] schematically illustrates a cooling architecture for a cryogenic and superconducting powertrain operating at cryogenic temperature according to one embodiment of the invention; [Fig. 3] schematically illustrates a cooling architecture for a cryogenic and superconducting powertrain operating at cryogenic temperature according to another embodiment of the invention; [Fig.[Fig. 4] schematically illustrates a cooling architecture for a cryogenic and superconducting powertrain operating at cryogenic temperature according to another embodiment of the invention; [Fig. 5] schematically illustrates an aircraft equipped with an architecture according to the present invention.

[0028] Fig. 1 represents in a general and simplified way a cooling architecture 30 for a cryogenic and superconducting powertrain operating at cryogenic temperature.

[0029] The cryogenic and superconducting powertrain 10 comprises: - a superconducting electric motor 12, including a drive shaft, - units of motor control MCU 14, also called control units, configured to control all aspects of operation of the superconducting electric motor 12, - superconducting distribution and protection devices 20, also called DCc cables 20 or DCc lines 20, - at least one fuel cell 22, which in this architecture is used as a DC power supply source, - current leads 24 to the fuel cell 22 (Fig. 1 being very simplified to make the overall architecture understandable, they do not appear in Fig. 1 but are illustrated in Figures 2 to 4), - a heat management system 28 for the fuel cell which will not be described further as it is not part of the innovation itself.

[0030] A propeller 16 can be driven by the motor 12 directly or indirectly, namely through a transmission, a clutch system or any other necessary system.

[0031] DC / DC converters used to adapt the voltage levels between the DCc cables 20 and the current leads 24 have a certain weight. Furthermore, they have greater heat dissipation than the other components, as the temperature rise of the GHe is greater through these converters than in the other components (with the exception of the MCU control units 14).

[0032] However, the powertrain can operate perfectly well without a converter: it is enough to adjust the length of the current leads 24 and the energy source (the fuel cells 22) to adapt the voltage levels and allow the direct connection between the DCc cables and the current leads 24. Therefore, the present architecture does not have converters.

[0033] As shown in Figures 1 to 4, the cooling architecture 30 comprises: - a reservoir 32 of a first fluid Fl, here liquid hydrogen LH2 for cryogenic temperature storage, - circulation lines of the first fluid (here LH2) 34 starting at the reservoir 32, - a reservoir 35 of a second fluid F2, here gaseous helium GHe at ambient temperature; - a single heat exchanger 36 between the first fluid Fl (here LH2) and the second fluid F2 (here GHe), - at least one cryostat 38 of the second fluid for cooling the MCU 14 and the superconducting electric motor 12 separately or together, - circulation lines of the second fluid, here GHe 42, between the heat exchanger 36 and said cryostat 38.

[0034] The cooling architecture 30 comprises a primary heating loop 100 using the first fluid LH2 and a secondary cooling loop 102 using the second fluid GHe. The two loops have a common section at the heat exchanger 36 where the first fluid cools the second fluid and, consequently, heats itself. The heating loop 100 using the first fluid is arranged and configured to heat the first fluid, namely Here, hydrogen is at cryogenic temperature at the outlet of tank 32, ensuring it is at a temperature suitable for use by the fuel cell 22. If heating by the second fluid is insufficient, a supplementary heating device can be provided, such as an electric device or another heat exchanger using a third fluid, such as glycol water. The secondary cooling loop 102 is arranged and configured to cool the second fluid to cool the powertrain components. The secondary cooling loop 102 is cooled by the flow of the first fluid, LH2, and in turn heats it, allowing it to then enter the fuel cell 22.

[0035] As shown in [Fig. 1], the cooling architecture 30 includes a heat exchanger 36 for transferring heat from the first fluid to the second fluid, namely, in the following description, but not limited to, gaseous helium (GHe) to liquid hydrogen (LH2). The second fluid in the heat exchanger 36 can be another inert fluid besides helium, for example, liquid neon or liquid nitrogen (N2). Preferably, gaseous helium is used in the secondary cooling loop 102 because it is less expensive than neon, is an inert element (significantly reducing the safety risk compared to hydrogen), and is lightweight. Furthermore, helium is the only element with a lower boiling point than hydrogen; therefore, it will be in its gaseous phase in all possible aircraft scenarios.Helium is stored in tank 35, which allows the pressure in loop 102 to remain almost constant regardless of the helium temperature.

[0036] As shown in Figures 2 to 4, the cooling architecture 30 also includes: - at least one cryogenic recirculation fan 44 (44a, 44b) to recirculate the helium coolant in different powertrain components according to the embodiments which will be described below; - insulated cryogenic lines 54a-j to convey the cryogenic fluid between different components of the architecture.

[0037] Several embodiments are described below. In all these embodiments, the cooling architecture 30 of the cryogenic powertrain 10 is shown for a single superconducting motor 12 with two separate channels. A single-channel configuration refers to the cryogenic powertrain 10 with a superconducting electric motor 12 coupled to a single motor control unit 14 (MCU), a DC power cable 20, and current leads 24 Ld to the fuel cell 22. Here, two channels are used to eliminate the electrical dependence on a single channel. Thus, even if only one electrical channel fails, the powertrain 10 would be able to operate, albeit in a degraded mode.

[0038] In all embodiments also, a single heat exchanger 36 is arranged to transfer heat between hydrogen and helium.

[0039] A major constraint is the inlet temperature of the superconducting engine 12, which must be kept as low as possible. Given the flow rate of the second fluid, namely helium, entering the power unit and knowing the dissipation of each component of the power unit 10, the temperature at each point of the cooling architecture 30 is calculated accordingly.

[0040] According to the invention, the second fluid, GHe, stored in a pressurized tank 35, is used as a cooling source. A gaseous helium fluid (GHe) is used in a closed circuit according to the secondary cooling loop 102 to cool the electrical components of the cryogenic and superconducting powertrain 10. The flow rate of GHe helium in the closed circuit is regulated by the cryogenic fan 44.

[0041] A predetermined quantity of a second fluid F2 is cooled to a predetermined temperature, using the first fluid Fl, before being injected into the superconducting power unit, engine 12 of the power unit 10. For example, helium (He) is cooled by hydrogen (H2). The flow rate of the second fluid to be cooled circulating from the heat exchanger 36 to the superconducting engine 12 is calculated based on the constraints arising from the power unit.

[0042] The second fluid, namely helium, previously cooled by hydrogen, is heated by the heat dissipated from the superconducting engine 12, allowing the superconducting engine 12 to remain at an operating temperature below a maximum temperature threshold (beyond which the engine may no longer function correctly). The same principle applies to all the components of the powertrain.

[0043] The secondary cooling loop 102 comprises, downstream of the motor, two parallel cooling lines 102a and 102b. The flow of the second fluid that has cooled the motor divides into two flows along the two parallel cooling lines 102a, 102b between the motor and the heat exchanger: - a cooling line 102a for the control units; - a cooling line 102b in series with the DCc cables and current supplies Ld; the two cooling lines 102a, 102b then rejoin downstream of the control units 14, the cables 20, the current supplies 24 into a single line to the heat exchanger to form the loop 102.

[0044] The architecture more precisely comprises: - a cryogenic conduit 54a between the heat exchanger and the engine, the conduit being said to be cryogenic because it is capable of transporting a fluid at cryogenic temperature and maintaining it at that temperature; - a cryogenic conduit 54b between the engine and the control units; - a 54c cryogenic conduit between the motor and the DCc cables; - a cryogenic conduit 54d between the DCc cables and the current supplies; - a 54e cryogenic conduit between the control units and the exchanger; - a cryogenic conduit 54f between the current inlets and the exchanger, the cryogenic conduits 54e and 54f meeting in a single conduit 54g for the return to the exchanger.

[0045] Thus, the cooling fluid cools the motor and then divides into two flows: one for cooling the control units and the other for cooling the DC-C cables and, in series, the power supply lines. These two flows create two independent cooling lines, protecting the DC-C cables from the outgoing flow from the control units, whose dissipation, as previously mentioned, is greater. This provides an alternative in the form of segregation, avoiding the series cooling of all components found in other types of architectures.

[0046] The flow rate of the second fluid GHe in the closed circuit is regulated by the cryogenic fan 44 placed on the cooling loop 102 upstream of the exchanger 36.

[0047] The second fluid F2 (GHe) is cooled to a certain temperature by the first fluid Fl (LH2). The second fluid F2 (GHe) exiting the superconducting motor 12 is used to cool the DCc cables 20 and the current leads (Ld) to the fuel cell 22 (as shown in Figures 2 to 4).

[0048] The second cold fluid F2 (GHe) is also used at the engine outlet to maintain the engine control units 14 (MCUs) at the required cold temperature. The second hot fluid F2 (GHe) from the lines 24 and the control units 14 is then returned to the heat exchanger 36 via the return line 54g with the help of the fan 44.

[0049] Thus, none of the components of the powertrain are subjected to a temperature exceeding their maximum permissible temperature.

[0050] This cooling architecture 30 includes control valves 46 (e.g., remote control valves). For example, in Figures 2, 3, and 4, a valve 46a is arranged on each first fluid (LH2) line 34 to the heat exchanger 36, and additional valves are also arranged on different cryogenically insulated lines depending on the embodiment: valve 46c on line 54e in embodiments [Fig. 2] and 4, valve 46d on line 54f in embodiment [Fig. 3], and valves 46e and 46f respectively on lines 54f and 54e in embodiment [Fig. 4]. The operation of the valves is not detailed here, and their positioning in The architecture may be different. Other valves may also be added or removed.

[0051] In all the configurations illustrated in Figures 2, 3, and 4, the dashed squares indicate a cryostat dedicated to the respective components that must be kept at a low temperature. As mentioned previously, the superconducting motor 12 and the MCUs are arranged in the same cryostat 38. However, it is possible to provide one or more separate cryostats for the motor and the MCUs. Each superconducting distribution and protection device 20 is arranged in a dedicated cryostat 48a, 48b. Similarly, one or more cryostats could be provided for the assembly or groups of devices 20. The current leads 24 are arranged in a separate cryostat 50a, 50b. More specifically, as shown in [Fig.2], the power supplies 24 of the power unit 10 are divided into two power lines, each power line of the power supplies 24 is arranged in a dedicated cryostat 50a, 50b.Here again, one or more cryostats could be provided for the entire set or groups of current feeds 24. It is also possible to provide each current feed in the same cryostat as its respective cable (i.e., the one to which it is connected), rather than separate cryostats for the feeds and cables. In this case, as before, one or more cryostats could also be provided for the entire set or groups of feeds with their respective cables. The cryogenic fan 44 and the heat exchanger 36 can also be arranged in a common or dedicated cryostat 52. According to one possible embodiment, the heat exchanger 36 is arranged in a cryostat 52, near the first fluid reservoir 32, to distribute the hydrogen in liquid form over the shortest possible distance. Generally, this cryostat 52 and the fuel cell 22 are arranged close to each other.

[0052] With the cooling architecture 30 above, various configurations of the cryogenic and superconducting powertrain 10 are possible.

[0053] Fig. 2 represents a first cooling architecture 30 of a cryogenic and superconducting power unit 10 in which the components of the power unit 10 are cooled using a single cooling loop 102 of the second fluid cooled by the exchanger 36. In the embodiments described below, several cooling loops are proposed, knowing that, as seen previously, the or one of the cooling loops 102 is divided into two cooling loops 102a and 102b.

[0054] According to this embodiment of the invention, no specific details are added to the description of the overall architecture given above. In the cooling architecture 30 of the cryogenic and superconducting powertrain 10 shown in [Fig. 2], the second fluid is cooled to a temperature predetermined, using the first fluid in the heat exchanger 36, before being injected into the superconducting powertrain. The flow of the second fluid, heated by the engine, exits the heat exchanger and splits into two parallel flows: one for cooling the units 14 and the other for cooling the cables 20 and the power supply lines 24 connected in series. The flows of the second fluid exiting the units 14 and joining in a conduit 54e, and the flows of the second fluid exiting the power supply lines 24 and joining in a conduit 54f, then join in a single conduit 54g to pass through the heat exchanger 36 again, driven by the fan 44, and form the loop 102.

[0055] Fig. 3 represents a second embodiment of the cooling architecture 30 of a cryogenic and superconducting power unit 10 in which the components of the power unit 10 are cooled using two cooling loops 102, 102' of the second fluid, one 102 in which the second fluid F2 is cooled by the exchanger 36, the other 102' in which the second fluid F2 is not cooled by the exchanger.

[0056] The second cooling loop 102' connects the cryogenic line 54h upstream of the heat exchanger 36 (the line 54h being located more precisely between the fan 44 and the heat exchanger 36) to the outlet of the motor 12 at the point of the line 54b which connects the motor to the MCUs 14. More specifically, in the illustrated form, it connects the fan 44 to said motor outlet via a line 54i. The flow of second GHe fluid exiting the superconducting motor 12 is mixed with the flow of second GHe fluid from the fan 44 before entering the MCUs 14. The flow thus created enters the MCUs 14 and is heated by the MCUs 14, due to the dissipation of the MCU 14.Next, the second GHe fluid follows the 54g line and passes into the cryogenic fan 44 to be drawn again into two loops 102 and 102', one in the heat exchanger 36 to be cooled by the first LH2 fluid, at a certain temperature and the other towards the motor outlet linked to the MCUs without being cooled by the exchanger.

[0057] Due to an additional cooling loop 102', this embodiment of the cooling architecture 30 includes an additional control valve 46 46h to regulate the flow rate arriving directly at the inlet of the MCU units. The valve 46h is located on the conduit 54i. Thus, the valve 46c located on the conduit 54e in the first embodiment is no longer necessary. It is relocated to the conduit 54i. Apart from this additional loop 102' and the additional or differently positioned control valves, the rest of the architecture is equivalent to the first embodiment illustrated in [Fig. 2].

[0058] Figure 4 represents a third form of realization of architecture 30 identical to that of [Fig.2] in which a local cooling loop 102 is created in addition to this architecture at the level of the MCUs 14 control units. The line 54b at the motor outlet and the line 54e at the outlet of the MCUs are connected by an additional line 54j to form a local cooling loop for the MCUs control units: a cryogenic recirculation fan 44, referenced 44b (relative to the fan upstream of the heat exchanger referenced 44a), is introduced into this loop at the level of the line 54j to draw the flow of the second fluid GHe exiting the MCUs partially back towards the MCUs. As seen previously, the MCUs control units exhibit greater heat dissipation than the other components. An additional local loop compensates for this difference with the other components. As indicated by the direction of the arrows in [Fig.[4], the second fluid exiting the engine is conveyed to the control units 14 and, exiting the control units 14, partially back to their inlets by means of the fan 44 and partially to the heat exchanger 36. A valve 46e is added at the outlet of the power inlets 24 at the level of the line 54f. knowing that a valve 46f is provided at the level of the line 54e. .

[0059] Figure 5 represents an example of a hydrogen-powered aircraft equipped with of such a cooling architecture. Components of the propulsion system described above, in particular the control units 14, the cables 20 and the feed lines 24, are positioned in a box, called the hydrogen box, known as a pod, installed in a nacelle 140 of the aircraft. The tanks 32, 35, the heat exchanger 36 and the fan 44a are positioned in the fuselage 150 or the wing 160.

[0060] The systems and devices described herein may include a controller or a computer device comprising a processing unit and a memory in which computer-executable instructions are stored to implement the processes described herein. The processing unit may include any suitable device configured to trigger the execution of a series of steps in such a way as to implement the process so that the instructions, when executed by the computer device or other programmable device, can trigger the functions / actions / steps specified in the methods described herein to be performed.The processing unit may include, for example, any type of general-purpose microprocessor or microcontroller, a digital signal processor (DSP), a central processing unit (CPU), an integrated circuit, a field-programmable gate array (FPGA), a reconfigurable processor, other suitably programmed or programmable logic circuits, or any combination thereof.

[0061] The memory can be any known storage medium or other machine-readable storage medium. The memory may include a non- Computer-readable transient memory, such as, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination thereof. Memory may include a suitable combination of any type of computer memory located either inside or outside the device, such as, for example, random access memory (RAM), read-only memory (ROM), a compact disc-based memory (CD-ROM), electro-optical memory, magneto-optical memory, programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), ferroelectric RAM (FRAM), or the like. Memory may include any storage means (e.g., devices) suitable for retrievably storing computer-executable instructions that can be executed by the processing unit.

[0062] The methods and systems described herein can be implemented in a high-level procedural or object-oriented programming or scripting language, or a combination thereof, to communicate with or assist the operation of the controller or computer device. Alternatively, the methods and systems described herein can be implemented in assembly or machine language. The language can be compiled or interpreted. The program code for implementing the methods and systems described herein can be stored on the storage medium or device, for example, a ROM, magnetic disk, optical disc, USB flash drive, or any other suitable storage medium or device. The program code can be readable by a general-purpose or specialized programmable computer to configure and operate the computer when the storage medium or device is read by the computer to execute the procedures described herein.

[0063] Executable computer instructions can take many forms, including modules, executed by one or more computers or other devices. Generally, modules include routines, programs, objects, components, data structures, etc., that perform specific tasks or implement particular abstract data types. Generally, the functionalities of modules can be combined or distributed as desired in various embodiments.

[0064] Although at least one example of an embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions, and alternatives may be apparent to a person skilled in the art and may be made without departing from the scope of this disclosure. This disclosure is intended to cover all adaptations or variations of the example embodiment(s). Furthermore, in this description, the terms "include" or "comprising" do not exclude other elements or steps, and the terms "a" or "one" do not exclude not a plural number, and the term "or" means either one or both. Furthermore, the features or steps described may also be used in combination with other features or steps and in any order, unless the disclosure or context suggests otherwise. This disclosure incorporates by reference the full disclosure of any patent or application from which it claims benefit or priority.

Claims

Demands

1. Cryogenic and superconducting powertrain comprising: - at least one superconducting electric motor (12), - at least one motor control unit (MCU) (14) configured to control the operating aspects of the superconducting electric motor (12), - at least one superconducting distribution and protection device (20), called a DCc cable (20); - at least one main current supply (24) to a fuel cell (22), - a cooling architecture (30) comprising: - a tank of a first fluid (32) for storing said first fluid at cryogenic temperature, - a tank (35) of a second fluid;- a heat exchanger (36) configured to exchange heat between the first fluid and a second fluid, the second fluid following at least one cooling loop (102) of components (12, 14, 20, 24) starting with the motor (12), the cooling loop (102) comprising two parallel cooling lines between the motor (12) and the exchanger (36): - a cooling line (102a) of the control units (14); - a cooling line (102b) in series with the DCc cables (20) and power supplies (24); the two lines (102a) and (102b) coming from the motor (12) and joining into a single line to the exchanger (36).

2. Cryogenic and superconducting powertrain (10) according to claim 1, wherein the first fluid comprises liquid hydrogen (LH2) and the second fluid comprises gaseous helium (GHe).

3. Cryogenic and superconducting powertrain (10) according to any one of the preceding claims, wherein the cooling architecture (30) includes a primary heating loop (100) for the first fluid so as to heat it for use by a fuel cell (22) and a secondary cooling loop (102) for the second fluid so as to cool it to cool all of said components (12, 14, 20, 24).

4. Cryogenic and superconducting powertrain (10) according to the preceding claim, wherein the secondary cooling loop (102) is arranged and configured to cool components (12, 14, 20, 24) of the cryogenic and superconducting powertrain.

5. Cryogenic and superconducting powertrain (10) according to the preceding claim, wherein the secondary cooling loop (102) is cooled by the second fluid flow, and in return heats the first fluid which enters the fuel cell (22).

6. Cryogenic and superconducting power unit (10) according to any one of the preceding claims, further comprising: - at least one cryogenic recirculation fan (44a, 44b) for recirculating the second fluid in the cryogenic and superconducting components of the power unit in a fully closed loop, and - cryogenic insulated lines (54a-j), for conveying the cryogenic fluid to the electrical components of the cryogenic and superconducting power unit (10).

7. Cryogenic and superconducting powertrain (10) according to any one of the preceding claims, wherein the cooling architecture (30) includes an additional cooling line (102') provided to conduct the flow of second fluid upstream of the exchanger, namely not cooled by it, to the inlet of the MCU control units (14).

8. Cryogenic and superconducting powertrain (10) according to any one of claims 1 to 6, wherein the cooling architecture (30) includes an additional local cooling line (102”) provided to conduct the flow of second fluid downstream of the units (14) to the inlet of said control units.

9. Cryogenic and superconducting powertrain (10) according to the preceding claim, wherein the cooling architecture (30) includes a second fan (44b) enabling the flow downstream of the units (14) to be driven towards the inlet of said control units.

10. Aircraft comprising a powerplant according to any one of the preceding claims, wherein the tanks (32, 35) and the heat exchanger (36) are located in the aircraft fuselage and components of the cooling architecture (30) are located in a pod in a nacelle (140).

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