Electric propulsion system based on fuel cell

Abstract

The embodiment of the utility model discloses an electric propulsion system based on a fuel cell. The electric propulsion system comprises a motor, a motor controller, a lithium battery system, a fuel cell system and a thermal management system. Wherein the fuel cell system and the lithium battery system are used for supplying power to the motor controller; the motor controller is connected with the motor, the motor controller is used for controlling the motor to output specified power and rotating speed, and the motor is used for driving an aircraft propelling device; the thermal management system comprises a first heat exchange device, a second heat exchange device and a control device, wherein the first heat exchange device is used for exchanging heat with components of the fuel cell system; the second heat exchange device is used for carrying out heat exchange with components of the lithium battery system; and the third heat exchange device is used for carrying out heat exchange with the motor controller.

Description

Technical Field

[0001] The present application relates to the technical field of electrical systems, and in particular to an electric propulsion system based on a fuel cell. Background Art

[0002] In the context of global civil aviation emission reduction, hydrogen energy has become the first choice for zero-carbon emission energy. There are two ways to convert hydrogen energy into aircraft power: hydrogen-burning turbines and electric propulsion based on hydrogen fuel cells (hereinafter referred to as "hydrogen-electric propulsion"), among which hydrogen-electric propulsion has higher energy utilization efficiency than hydrogen turbines. Among them, the fuel cell system uses electrochemical reactions to generate DC power from hydrogen and air. The electric propulsion system can distribute the DC power supply to single / multiple propulsion motors on the wings and fuselage to provide power, and provide thrust for the aircraft through the motor-driven power device (electric ducted fan, propeller, etc.).

[0003] The existing technologies, such as the patents currently disclosed, only consider part of the grid design, thermal management design and equipment layout for the design of hydrogen-electric propulsion, but fail to make comprehensive considerations, which will lead to the problem of overweight of the power unit. Utility Model Content

[0004] The embodiments of this specification provide an electric propulsion system based on a fuel cell to solve the comprehensive design problems of hydrogen-electric propulsion grid design, equipment layout and thermal management.

[0005] To solve the above technical problems, the embodiments of this specification provide the following technical solutions:

[0006] The embodiment of this specification provides an electric propulsion system based on a fuel cell, the electric propulsion system comprising a motor, a motor controller, a lithium battery system, a fuel cell system and a thermal management system;

[0007] Wherein, the fuel cell system and the lithium battery system are used to power the motor controller;

[0008] The motor controller is connected to the motor, and the motor controller is used to control the motor to output a specified power and speed, and the motor is used to drive the aircraft propulsion device;

[0009] The thermal management system comprises:

[0010] a first heat exchange device, for exchanging heat with a component of the fuel cell system;

[0011] A second heat exchange device, used for performing heat exchange with components of the lithium battery system;

[0012] The third heat exchange device is used for performing heat exchange with the motor controller.

[0013] Optionally, the lithium battery system includes a lithium battery pack and a high-voltage control box, and the fuel cell system includes a fuel cell stack, a BOP system and a fuel cell controller;

[0014] The output end of the BOP system is connected to the high-voltage control box;

[0015] An energy management controller is provided in the high-voltage control box, and the energy management controller is connected to the fuel cell controller;

[0016] The high voltage control box is connected to the motor controller.

[0017] Optionally, the electric propulsion system further includes a first switch control unit to a fifth switch control unit;

[0018] Wherein, the first switch control unit is connected to the positive electrode or negative electrode of the discharge resistor and the motor controller respectively;

[0019] The second switch control unit is connected to the positive electrode of the BOP system and the bus bar in the high-voltage control box respectively;

[0020] The third switch control unit is respectively connected to the pre-charging resistor and the bus bar in the high-voltage control box;

[0021] The fourth switch control unit is connected to the positive electrode of the lithium battery pack and the bus bar in the high-voltage control box respectively;

[0022] The fifth switch control unit is connected to the negative electrode of the lithium battery pack and the bus bar in the high-voltage control box respectively.

[0023] Optionally, the energy management controller is used to control the opening and closing of the first to fifth switch control units.

[0024] Optionally, the drive circuits of the fourth switch control unit and the fifth switch control unit are connected to a switch control device, the energy management controller is connected to the switch control device, and the switch control device is connected to a low-voltage power supply output by the lithium battery system and / or an aircraft low-voltage power supply.

[0025] Optionally, the thermal management system further includes a phase change storage device, a fourth heat exchange device and a fifth heat exchange device;

[0026] Among them, the fourth heat exchange device is used to perform heat exchange with the phase change storage; the first heat exchange device is connected to the fourth heat exchange device and the fifth heat exchange device through pipelines, the second heat exchange device is connected to the fourth heat exchange device and the fifth heat exchange device through pipelines, and the third heat exchange device is connected to the fourth heat exchange device and the fifth heat exchange device through pipelines.

[0027] Optionally, the thermal management system further includes a sixth heat exchange device;

[0028] Wherein, the sixth heat exchange device is used for heat exchange with air; the sixth heat exchange device is respectively connected with the first heat exchange device, the second heat exchange device and the third heat exchange device through pipelines.

[0029] Optionally, the thermal management system further includes a phase change storage device, a seventh heat exchange device and an eighth heat exchange device;

[0030] Among them, the seventh heat exchange device is used to exchange heat with the phase change storage; the first heat exchange device is connected to the seventh heat exchange device and the eighth heat exchange device through pipelines, and the third heat exchange device is connected to the seventh heat exchange device and the eighth heat exchange device through pipelines.

[0031] Optionally, the electric propulsion system further includes a hydrogen storage device, and the hydrogen storage device is used to supply hydrogen to the fuel cell system.

[0032] Optionally, the electric propulsion system further includes a phase change refrigeration device, which is used to dissipate heat from the first heat exchange device and / or the second heat exchange device and / or the third heat exchange device.

[0033] At least one of the above technical solutions adopted in the embodiments of this specification can achieve the following beneficial effects:

[0034] It can not only realize the combined power supply of hydrogen and lithium batteries through fuel cells and lithium batteries, but also realize the heat exchange of the fuel cell system, lithium battery system and motor controller, so as to manage the heat generation of the fuel cell system, lithium battery system and motor controller and improve the electric propulsion effect and efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of this specification or the prior art, the drawings required for use in the embodiments of this specification or the prior art description are briefly described below. Obviously, the following only describes the drawings required for use in some embodiments of this application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor.

[0036] Figure 1 It is a schematic diagram of the architecture of the electric propulsion system in the first embodiment of this specification.

[0037] Figure 2 It is a schematic diagram of the layout of the electric propulsion system in the first embodiment of this specification.

[0038] Figure 3 It is a schematic diagram of the high-voltage electrical architecture of the electric propulsion system in the first embodiment of this specification.

[0039] Figure 4 It is a schematic diagram of the low-voltage electrical architecture of the electric propulsion system in the first embodiment of this specification.

[0040] Figure 5 It is a schematic diagram of the contactor control circuit of the electric propulsion system in the first embodiment of this specification.

[0041] Figure 6 Schematic diagram of thermal management of the electric propulsion system in the second embodiment of this specification.

[0042] Figure 7 Schematic diagram of thermal management of the electric propulsion system in the third embodiment of this specification.

[0043] Figure 8 It is a schematic diagram of thermal management of the electric propulsion system in the fourth embodiment of this specification. DETAILED DESCRIPTION

[0044] In order to enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments involved in the specific implementation methods are only part of the embodiments of this application, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the specific implementation methods without making creative work should belong to the scope of protection of this application.

[0045] like Figure 1 and Figure 2 As shown, the first embodiment of this specification (hereinafter referred to as "embodiment one") provides an electric propulsion system based on a fuel cell. The electric propulsion system includes a motor, a motor controller, a lithium battery system, a fuel cell system and a thermal management system.

[0046] The fuel cell system and the lithium battery system are used to supply power to the motor controller.

[0047] The motor controller is connected to the motor, specifically, the output end of the motor controller is connected to the motor, and the motor controller is used to control the motor to output a specified power and speed. The motor is connected to the aircraft propulsion device, and is used to drive the aircraft propulsion device (the aircraft propulsion device can be a propeller) to operate, thereby providing power for the aircraft.

[0048] The thermal management system comprises:

[0049] a first heat exchange device, for exchanging heat with a component of the fuel cell system;

[0050] A second heat exchange device, used for performing heat exchange with components of the lithium battery system;

[0051] The third heat exchange device is used for performing heat exchange with the motor controller.

[0052] In the first embodiment, the electrical design of the electric propulsion system includes both a high-voltage electrical architecture and a low-voltage electrical architecture, thereby providing hybrid or combined power supply for the aircraft.

[0053] The high voltage electrical architecture is described below:

[0054] like Figure 3 As shown, the lithium battery system may include a lithium battery pack and a high-voltage control box, and the fuel cell system may include a fuel cell stack, a BOP system and a fuel cell controller.

[0055] The output end of the BOP system is connected to the high-voltage control box, which can be the output end of the BOP system connected to the input end of the high-voltage control box, specifically, the high-voltage DC end of the DCDC output in the BOP system is connected to the bus of the high-voltage control box, so that the fuel cell and lithium battery can be used to provide mixed or combined power for the motor driver through the high-voltage control box.

[0056] An energy management controller is provided in the high-voltage control box (i.e., the energy management controller is integrated in the high-voltage control box), and the energy management controller is connected to the battery management slave and the fuel cell controller (for example, via a communication bus). Among them, the battery management system is a system for monitoring, controlling and protecting lithium battery packs. The battery management system usually includes a battery management host and a battery management slave. The battery management slave can be used as part of the lithium battery pack, and the function of the battery management host can be replaced or realized by the energy management controller. In this way, on the basis of being compatible with the functions of the main battery management system, the energy management controller can realize more control logic and improve the integration of the electric propulsion system.

[0057] The high-voltage control box is connected to the motor controller, and the output end of the high-voltage control box may be connected to the motor controller, and specifically, the bus of the high-voltage control box may be connected to the input end of the motor controller.

[0058] The electric propulsion system may further include a first switch control unit (hereinafter referred to as K1), a second switch control unit (hereinafter referred to as K2), a third switch control unit (hereinafter referred to as K3), a fourth switch control unit (hereinafter referred to as K4) and a fifth switch control unit (hereinafter referred to as K5), each of which may be a contactor or other device with a switch control function.

[0059] In Example 1, the first switch control unit is respectively connected to the discharge resistor (which can be set in the high-voltage control box) and the positive or negative electrode of the motor controller; the second switch control unit is respectively connected to the positive electrode of the BOP system and the bus in the high-voltage control box; the third switch control unit is respectively connected to the pre-charge resistor (which can be set in the high-voltage control box) and the bus in the high-voltage control box; the fourth switch control unit is respectively connected to the positive electrode of the lithium battery pack and the bus in the high-voltage control box; the fifth switch control unit is respectively connected to the negative electrode of the lithium battery pack and the bus in the high-voltage control box.

[0060] In the first embodiment, the energy management controller is used to control the opening and closing of the first to fifth switch control units. Specifically, the control logic under the high-voltage electrical architecture (which can be implemented by the energy management controller) is as follows:

[0061] System power-on pre-charge: Check whether there is any alarm information in the electric propulsion system. If it is confirmed that there is no alarm information, close K5, then close K3, and detect the output voltage of the lithium battery pack and the input voltage of the lithium battery of the high-voltage control box;

[0062] Lithium battery powered; when the voltages at both ends are close (the similarity judgment condition can be set), K4 is closed and K3 is disconnected, and the lithium battery directly powers the motor controller.

[0063] Fuel cell power supply: After the energy management controller detects that the bus voltage is stable, K2 is closed and the fuel cell is connected to the grid. The lithium battery and the fuel cell simultaneously power the motor controller. According to the flight conditions, the energy management controller controls the output power value of the fuel cell through the preset control logic.

[0064] Fuel cell power off: When power needs to be turned off, first disconnect the fuel cell power supply, then disconnect the lithium battery power supply (i.e. lithium battery power off), that is, disconnect K2 first.

[0065] Disconnect the lithium battery: first disconnect the positive electrode K4, then disconnect the negative electrode K5.

[0066] Capacitor discharge: After the lithium battery and fuel cell are cut off from the power grid, close K1 to consume the energy of the capacitor in the motor controller.

[0067] The following is an explanation of the low voltage electrical architecture:

[0068] In the first embodiment, the reliability of the power supply of the power grid can be ensured from the aspects of low-voltage power supply and relay setting. In order to avoid the failure of the motor controller, energy management controller or fuel cell controller due to a single point failure of the low-voltage power supply, two different power supply forms are provided in the first embodiment, namely, the low-voltage power supply converted (i.e. output) by the lithium battery system DCDC (or written as "DC / DC") from the high-voltage power supply of the lithium battery pack and the low-voltage power supply of the aircraft (aircraft).

[0069] like Figure 4 As shown, the lithium battery system may include a lithium battery pack and a high-voltage control box, the fuel cell system may include a fuel cell stack, a BOP system and a fuel cell controller, and an energy management controller is arranged in the high-voltage control box.

[0070] The DCDC output end of the lithium battery system is connected to the low-voltage bus (inside the high-voltage control box) to convert the high-voltage power of the lithium battery pack into low-voltage power supply. The low-voltage power supply of the aircraft is also connected to the same low-voltage bus to jointly power the motor controller, energy management controller, fuel cell controller, etc. of the electric propulsion system. The energy management controller, the control board in the motor controller, and the control end of the fuel cell controller are all connected to the low-voltage bus and draw power from the bus.

[0071] In the first embodiment, the electric propulsion system also includes a separately arranged switch control device, which may be a two-position relay or other device with a switch control function. The drive circuits of the fourth switch control unit and the fifth switch control unit are connected to the switch control device, the energy management controller is connected to the switch control device, and the switch control device is connected to the low-voltage power supply output by the lithium battery system (i.e., the low-voltage power supply converted or output by the lithium battery system DCDC) and / or the aircraft low-voltage power supply. Taking the two-position relay as an example, the control circuit of the two-position relay is as follows: Figure 5 As shown, the driving circuits of the fourth switch control unit and the fifth switch control unit are connected or introduced with a two-position relay, the energy management controller is connected with the two-position relay, and the two-position relay is connected with the low-voltage power supply output by the lithium battery system DCDC and / or the low-voltage power supply of the aircraft. The circuit of the energy management controller driving the fourth switch control unit and the fifth switch control unit is not directly connected to the low-voltage end of the fourth switch control unit or the fifth switch control unit, but is directly connected to the two-position relay, and the two-position relay connects the low-voltage power supply and the low-voltage end of the fourth switch control unit or the fifth switch control unit. When the energy management controller fails, the fourth switch control unit or the fifth switch control unit will not be disconnected, and the fourth switch control unit or the fifth switch control unit can only be disconnected by issuing a disconnection control command.

[0072] Since the lithium battery is the final energy source of the aircraft, it is necessary to ensure that the two high-voltage switch control units, the fourth switch control unit or the fifth switch control unit, will not be disconnected due to a failure of the energy management controller (including a failure of the energy management controller control board).

[0073] In the first embodiment, the electric propulsion system may further include a hydrogen storage device, which is used to supply hydrogen to the fuel cell system. Specifically, the hydrogen storage device may be connected to the fuel cell stack through a pipeline.

[0074] The connection described in the first embodiment can be a mechanical connection, an electrical connection, a cable (including a power cable), an electrical connection, or other suitable connection, which can be set as needed. For example, in order to enable the motor to drive the propeller, the motor needs to be mechanically connected to the propeller, and in the electrical architecture, an electrical connection is selected.

[0075] The second embodiment of this specification (hereinafter referred to as "Embodiment 2") provides an electric propulsion system based on a fuel cell, and Embodiment 2 may include the content of Embodiment 1.

[0076] The thermal management principle and effect of the thermal management system of the electric propulsion system are described below through the second embodiment:

[0077] In the second embodiment, the first heat exchange device corresponds to the fuel cell stack, and the first heat exchange device can be installed with the fuel cell stack in a suitable manner, and the two can be in contact, so that the first heat exchange device and the fuel cell stack perform heat exchange. The second heat exchange device corresponds to the lithium battery pack, and the second heat exchange device can be installed with the lithium battery pack in a suitable manner, and the two can be in contact, so that the second heat exchange device and the lithium battery pack perform heat exchange. The third heat exchange device corresponds to the motor controller, and the third heat exchange device can be installed with the motor controller in a suitable manner, and the two can be in contact, so that the third heat exchange device and the motor controller perform heat exchange. The first heat exchange device, the second heat exchange device, the third heat exchange device, and other heat exchange devices appearing below can be heat exchangers, radiators, or other devices or products or components with heat exchange, heat dissipation, or cooling functions. The first heat exchange device, the second heat exchange device, and the third heat exchange device can be heat exchange devices, products, or components that come with the fuel cell stack, the lithium battery pack, and the motor controller.

[0078] In the second embodiment, the thermal management system further includes a phase change storage device, a fourth heat exchange device and a fifth heat exchange device. The fourth heat exchange device is used to perform heat exchange with the phase change storage device, the first heat exchange device is connected to the fourth heat exchange device and the fifth heat exchange device through pipelines, the second heat exchange device is connected to the fourth heat exchange device and the fifth heat exchange device through pipelines, and the third heat exchange device is connected to the fourth heat exchange device and the fifth heat exchange device through pipelines.

[0079] The fourth heat exchange device can be installed with the phase change storage device in a suitable manner, and the two can be in contact with each other, so that the fourth heat exchange device and the phase change storage device can perform heat exchange.

[0080] In the second embodiment, the thermal management principle and effect of each component of the electric propulsion system may include: each heat exchange device and pipeline of the thermal management system form a loop, and the cooling medium (such as water) can flow between each heat exchange device and pipeline. Through the flow of the cooling medium in the first heat exchange device, the second heat exchange device, and the third heat exchange device and the heat exchange function of the heat exchange device, the first heat exchange device dissipates heat or cools the fuel cell stack, the second heat exchange device dissipates heat or cools the lithium battery pack, and the third heat exchange device dissipates heat or cools the motor controller, and the heat is taken away by the cooling medium. On the one hand, the cooling medium after absorbing heat passes through the fourth heat exchange device, and the phase change storage device has a phase change material or a phase change medium, and its phase change material or phase change medium can undergo a phase change to absorb heat, so that the phase change storage device cools the cooling medium flowing through the fourth heat exchange device by heat exchange with the fourth heat exchange device; on the other hand, the medium after absorbing heat flows through the fifth heat exchange device, and the fifth heat exchange device can exchange heat with the air, thereby cooling the cooling medium flowing through the fifth heat exchange device. The cooled cooling medium continues to flow through the first heat exchange device and / or the second heat exchange device and / or the third heat exchange device to continue to dissipate heat or cool the fuel cell stack and / or the lithium battery pack and / or the motor controller. In this way, through the circulation of the cooling medium and heat exchange, the heat dissipation or cooling of the fuel cell stack and / or the lithium battery pack and / or the motor controller is achieved, thereby achieving a thermal management effect (i.e., achieving control over the heating of the components, the same below).

[0081] In order to facilitate the control of the flow of the cooling medium, components such as pumps or valves may be provided in the circuit. For example, a cooling pump, first to fourth valves, and an expansion water tank may be provided, and these components may also be included in the thermal management system. Each valve may be a three-way valve or other valves.

[0082] For example, Figure 6 As shown, the first heat exchange device (not shown, which may be located at the location of the fuel cell stack) is connected to the cooling pump (i.e., pump 1) and the second valve (i.e., valve 2) through pipelines, the cooling pump is connected to the first valve (i.e., valve 1) through pipelines, the fourth heat exchange device (i.e., heat exchange 4) is connected to the first valve and the second valve through pipelines, the fifth heat exchange device (i.e., heat exchange 5) is connected to the first valve, the expansion water tank, the second heat exchange device (i.e., heat exchange 2), and the third heat exchange device (i.e., heat exchange 3) through pipelines, the second heat exchange device and the third heat exchange device are connected to the fourth valve (i.e., valve 4) through pipelines, and the third valve (i.e., valve 3) is connected to the second valve, the fourth valve, and the expansion water tank through pipelines. A pump (i.e., pump 2) may be provided on the pipeline between the expansion water tank and the third valve.

[0083] More specifically, the output end of the first heat exchange device (the output end of each heat exchange device can be a liquid cooling output end, the same below) is connected to the cooling pump through a pipeline, and the input end of the first heat exchange device (the input end of each heat exchange device can be a liquid cooling input end, the same below) is connected to the second valve through a pipeline.

[0084] The input end of the fourth heat exchange device is connected to the first valve through a pipeline, and the output end of the fourth heat exchange device is connected to the second valve through a pipeline.

[0085] The fifth heat exchange device may have multiple input ends, and the multiple input ends are respectively connected to the second heat exchange device, the output end of the third heat exchange device, and the first valve through pipelines.

[0086] The output end of the fifth heat exchange device is connected to the expansion water tank through a pipeline (the medium in the expansion water tank can flow to the third valve).

[0087] The input end of the second heat exchange device and the input end of the third heat exchange device are respectively connected to the fourth valve through pipelines.

[0088] Through the above arrangement, the opening and closing of each valve and pump control pipeline can be used to control the flow path of the cooling medium, and freely control which heat exchange devices the cooling medium flows through, so as to achieve heat dissipation or cooling control of the fuel cell stack, lithium battery pack, motor controller, etc. For example, when one or more of the fuel cell stack, lithium battery pack, and motor controller are not working or do not need to be cooled or cooled by the cooling medium, the cooling medium can be controlled not to flow through the corresponding heat exchange device, so that it is not cooled or cooled or only relies on the corresponding heat exchange device to cool or cool it, which can also enhance the heat dissipation or cooling effect of other devices.

[0089] The cooling medium can flow between the fifth heat exchange device and the expansion water tank to achieve effects such as constant pressure and water replenishment.

[0090] like Figure 1 and Figure 2 As shown, the electric propulsion system can be arranged in the aircraft nacelle. The components of the electric propulsion system can be arranged according to the principle of proximity while ensuring the functions. For example, the motor controller, BOP system or high-voltage control box can be arranged in a position adjacent to the front end of the nacelle, and the phase change memory can be arranged near the fuel cell stack. The two are arranged together at the rear end of the nacelle, so that the cooling medium after the phase change memory absorbs heat can first flow through the first heat exchange device, thereby ensuring that the working temperature of the fuel cell is appropriate. In addition, the hydrogen storage device can be flexibly arranged in the nacelle or in the cabin according to the space of the nacelle. There is no specific limitation on the specific arrangement method.

[0091] Each heat exchange device itself can also exchange heat with the air. Since the nacelle has an opening, a stable flow can be provided to each heat exchange device during flight, making it convenient to remove the heat of each component (especially the heat from the fuel cell stack) through heat exchange and to air-cool the components.

[0092] In particular, when the aircraft is sliding out of the ground for takeoff, the incoming flow that each heat exchange device can receive is small, and the heat exchange effect with the air is poor. By setting up a phase change storage device, it is ensured that even if the incoming flow is small, the cooling medium can be effectively dissipated or cooled, thereby ensuring the heat dissipation or cooling effect of each heat-generating component of the electric propulsion system.

[0093] In addition, the cooling pump can be the pump in the BOP system, thereby realizing the reuse of the pump of the BOP system, which is beneficial to reducing the complexity of the system and reducing the weight of the system.

[0094] The third embodiment of the present specification (hereinafter referred to as "Embodiment 3") provides an electric propulsion system based on a fuel cell, and Embodiment 3 may include the contents of Embodiment 1.

[0095] The thermal management principle and effect of the thermal management system of the electric propulsion system are described below through the third embodiment:

[0096] In the third embodiment, the first heat exchange device corresponds to the fuel cell stack, and the first heat exchange device can be installed with the fuel cell stack in a suitable manner, and the two can be in contact, so that the first heat exchange device and the fuel cell stack can perform heat exchange. The second heat exchange device corresponds to the lithium battery pack, and the second heat exchange device can be installed with the lithium battery pack in a suitable manner, and the two can be in contact, so that the second heat exchange device and the lithium battery pack can perform heat exchange. The third heat exchange device corresponds to the motor controller, and the third heat exchange device can be installed with the motor controller in a suitable manner, and the two can be in contact, so that the third heat exchange device and the motor controller can perform heat exchange. The first heat exchange device, the second heat exchange device, the third heat exchange device, and other heat exchange devices appearing below can be heat exchangers, radiators, or other devices with heat exchange, heat dissipation, or cooling functions.

[0097] In the third embodiment, the thermal management system further comprises a sixth heat exchange device, wherein the sixth heat exchange device is used for heat exchange with air, and the sixth heat exchange device is respectively connected to the first heat exchange device, the second heat exchange device, and the third heat exchange device through pipelines.

[0098] In the second embodiment, the thermal management principle and effect of each component of the electric propulsion system may include: each heat exchange device and pipeline of the thermal management system form a loop, and the cooling medium can flow between each heat exchange device and pipeline. Through the flow of the cooling medium in the first heat exchange device, the second heat exchange device, and the third heat exchange device and the heat exchange function of the heat exchange device, the first heat exchange device dissipates heat or cools the fuel cell stack, the second heat exchange device dissipates heat or cools the lithium battery pack, and the third heat exchange device dissipates heat or cools the motor controller, and the heat is taken away by the cooling medium. The cooling medium after absorbing heat passes through the sixth heat exchange device, and the sixth heat exchange device can exchange heat with the air, thereby cooling the cooling medium flowing through the fifth heat exchange device. The cooled cooling medium continues to flow through the first heat exchange device and / or the second heat exchange device and / or the third heat exchange device, and continues to dissipate heat or cool the fuel cell stack and / or the lithium battery pack and / or the motor controller. In this way, through the circulation and heat exchange of the cooling medium, the heat dissipation or cooling of the fuel cell stack and / or the lithium battery pack and / or the motor controller is achieved, thereby achieving a thermal management effect.

[0099] In order to facilitate the control of the flow of the cooling medium, components such as pumps or valves may be provided in the circuit. For example, a cooling pump, a fifth valve, a sixth valve, and an expansion water tank may be provided, and these components may also be included in the thermal management system. Each valve may be a three-way valve or other valves.

[0100] For example, Figure 7 As shown, the first heat exchange device (not shown, which may be located at the location of the fuel cell stack) is connected to the fifth valve (i.e., valve 5) through a pipeline, the sixth heat exchange device (i.e., heat exchange 6) is respectively connected to the first heat exchange device, the second heat exchange device (i.e., heat exchange 2), the third heat exchange device (i.e., heat exchange 3) and the expansion water tank through pipelines, the second heat exchange device and the third heat exchange device are respectively connected to the sixth valve through pipelines, the fifth valve is respectively connected to the expansion water tank and the sixth valve (i.e., valve 6) through pipelines, and a pump may be provided on the pipeline between the expansion water tank and the fifth valve.

[0101] More specifically, the input end of the first heat exchange device is connected to the fifth valve through a pipeline, the output ends of the first heat exchange device, the second heat exchange device, and the third heat exchange device are respectively connected to the sixth heat exchange device through pipelines, the output end of the sixth heat exchange device is connected to the expansion tank through a pipeline (the medium in the expansion tank can flow to the fifth valve), and the input ends of the second heat exchange device and the third heat exchange device are respectively connected to the sixth valve through pipelines.

[0102] Through the above arrangement, the opening and closing of each valve and pump control pipeline can be used to control the flow path of the cooling medium, and freely control which heat exchange devices the cooling medium flows through, so as to achieve heat dissipation or cooling control of the fuel cell stack, lithium battery pack, motor controller, etc. For example, when one or more of the fuel cell stack, lithium battery pack, and motor controller are not working or do not need to be cooled or cooled by the cooling medium, the cooling medium can be controlled not to flow through the corresponding heat exchange device, so that it is not cooled or cooled or only relies on the corresponding heat exchange device to cool or cool it, which can also enhance the heat dissipation or cooling effect of other devices.

[0103] The cooling medium can flow between the sixth heat exchange device and the expansion water tank to achieve effects such as constant pressure and water replenishment.

[0104] In particular, the thermal management system in Example 3 is particularly suitable for cold environments (what constitutes a cold environment can be determined by relevant rules). The reasons include that the air temperature is low in a cold environment, and a better heat dissipation or cooling effect can be achieved through the incoming air flow. In addition, if you want to fly in a cold environment, you can first use an external power source to heat the lithium battery pack to the operating temperature through the PTC. In this way, during the ground taxiing phase, the lithium battery pack can maintain a high power output, the fuel cell can output a low power, and the heat can be dissipated or cooled through the above-mentioned thermal management principles. After takeoff, each heat exchange device uses the incoming air flow to enhance the heat dissipation or cooling capacity, the fuel cell can output at full power, and use the waste heat to keep the lithium battery pack warm. Among them, PTC is a thermistor, and its resistance value will increase when the temperature rises. PTC heating the lithium battery pack may include: using an external power source to energize the PTC, and the PTC generates a preset amount of heat to make the lithium battery pack reach the operating temperature.

[0105] The fourth embodiment of the present specification (hereinafter referred to as "embodiment four") provides an electric propulsion system based on a fuel cell, and embodiment four may include the content of embodiment one.

[0106] The thermal management principle and effect of the thermal management system of the electric propulsion system are described below through the fourth embodiment:

[0107] In the second embodiment, the first heat exchange device corresponds to the fuel cell stack, and the first heat exchange device can be installed with the fuel cell stack in a suitable manner, and the two can be in contact, so that the first heat exchange device and the fuel cell stack can perform heat exchange. The second heat exchange device corresponds to the lithium battery pack, and the second heat exchange device can be installed with the lithium battery pack in a suitable manner, and the two can be in contact, so that the second heat exchange device and the lithium battery pack can perform heat exchange. The third heat exchange device corresponds to the motor controller, and the third heat exchange device can be installed with the motor controller in a suitable manner, and the two can be in contact, so that the third heat exchange device and the motor controller can perform heat exchange. The first heat exchange device, the second heat exchange device, the third heat exchange device, and other heat exchange devices appearing below can be heat exchangers, radiators, or other devices with heat exchange, heat dissipation, or cooling functions.

[0108] In the fourth embodiment, the lithium battery pack can dissipate heat only by the incoming air, so the second heat exchange device can be the air heat dissipation device of the lithium battery pack.

[0109] In the fourth embodiment, the thermal management system further includes a phase change storage device, a seventh heat exchange device and an eighth heat exchange device. The seventh heat exchange device is used to perform heat exchange with the phase change storage device, the first heat exchange device is connected to the seventh heat exchange device and the eighth heat exchange device through pipelines, and the third heat exchange device is connected to the seventh heat exchange device and the eighth heat exchange device through pipelines.

[0110] The seventh heat exchange device can be installed with the phase change storage device in a suitable manner, and the two can be in contact with each other, so that the seventh heat exchange device and the phase change storage device can perform heat exchange.

[0111] In the fourth embodiment, the thermal management principle and effect of each component of the electric propulsion system may include: each heat exchange device (excluding the second heat exchange device) and the pipeline of the thermal management system form a loop, and the cooling medium can flow between each heat exchange device and the pipeline. Through the flow of the cooling medium in the first heat exchange device and the third heat exchange device and the heat exchange function of the heat exchange device, the first heat exchange device dissipates heat or cools the fuel cell stack, and the third heat exchange device dissipates heat or cools the motor controller, and the heat is taken away by the cooling medium. On the one hand, the cooling medium after absorbing heat passes through the seventh heat exchange device, and the phase change storage device has a phase change material or a phase change medium, and its phase change material or phase change medium can undergo a phase change to absorb heat, so that the phase change storage device cools the cooling medium flowing through the seventh heat exchange device by heat exchange with the seventh heat exchange device; on the other hand, the medium after absorbing heat flows through the eighth heat exchange device, and the eighth heat exchange device can exchange heat with the air, thereby cooling the cooling medium flowing through the eighth heat exchange device. The cooled cooling medium continues to flow through the first heat exchange device and / or the third heat exchange device, and continues to dissipate heat or cool the fuel cell stack and / or the motor controller. In this way, the heat dissipation or cooling of the fuel cell stack and / or motor controller is achieved through the circulation of the cooling medium and heat exchange, thereby achieving a thermal management effect.

[0112] In order to facilitate the control of the flow of the cooling medium, components such as pumps or valves may be provided in the circuit. For example, a cooling pump, the seventh valve to the ninth valve, and an expansion water tank may be provided, and these components may also be included in the thermal management system. Each valve may be a three-way valve or other valves.

[0113] For example, Figure 8 As shown, the first heat exchange device (not shown, which may be located at the location of the fuel cell stack) is respectively connected to the cooling pump (i.e., pump 1) and the eighth valve (i.e., valve 8) through pipelines, the cooling pump is connected to the seventh valve (i.e., valve 7) through pipelines, the seventh heat exchange device (i.e., heat exchange 7) is respectively connected to the seventh valve and the eighth valve through pipelines, the eighth heat exchange device (heat exchange 8) is respectively connected to the seventh valve, the expansion water tank, and the third heat exchange device (i.e., heat exchange 3) through pipelines, the third heat exchange device is connected to the ninth valve (i.e., valve 9) through a pipeline, the eighth valve and the ninth valve are connected through a pipeline, the expansion water tank and the eighth valve are connected through a pipeline, and a pump (i.e., pump 2) can be set on the pipeline between the expansion water tank and the eighth valve.

[0114] More specifically, the output end of the first heat exchange device is connected to the cooling pump through a pipeline, and the input end of the first heat exchange device is connected to the eighth valve through a pipeline.

[0115] The input end of the seventh heat exchange device is connected to the seventh valve through a pipeline, and the output end of the seventh heat exchange device is connected to the eighth valve through a pipeline.

[0116] The eighth heat exchange device may have multiple input ends, and the multiple input ends are respectively connected to the output end of the third heat exchange device and the seventh valve through pipelines.

[0117] The output end of the eighth heat exchange device is connected to the expansion water tank through a pipeline (the medium in the expansion water tank can flow to the ninth valve).

[0118] The input end of the third heat exchange device is connected to the ninth valve through a pipeline.

[0119] Through the above arrangement, the opening and closing of each valve and pump control pipeline can be used to control the flow path of the cooling medium, and freely control which heat exchange devices the cooling medium flows through, so as to achieve heat dissipation or cooling control of the fuel cell stack, lithium battery pack, motor controller, etc. For example, when one or more of the fuel cell stack and motor controller are not working or do not need to be cooled or cooled by the cooling medium, the cooling medium can be controlled not to flow through the corresponding heat exchange device, so that it is not cooled or cooled or only relies on the corresponding heat exchange device to cool or cool it, which can also enhance the heat dissipation or cooling effect of other devices.

[0120] The cooling medium can flow between the fifth heat exchange device and the expansion water tank to achieve effects such as constant pressure and medium replenishment.

[0121] In particular, the thermal management system in the fourth embodiment is particularly suitable for hot and humid environments (what is a hot and humid environment can be determined by relevant rules). If you want to fly in a hot and humid environment, the fuel cell stack maintains a high power output during the ground taxiing phase. Due to the hot and humid environment, the heat dissipation or cooling effect may be limited. The phase change storage device absorbs heat through phase change, thereby ensuring the heat dissipation or cooling effect of the cooling medium flowing out of the seventh heat exchange device. Then, the cooling medium flows from the seventh heat exchange device through the first heat exchange device, thereby improving the heat dissipation or cooling effect of the fuel cell stack. The heat dissipation of the lithium battery pack can be achieved by a second heat exchange device. For example, the second heat exchange device performs heat exchange with the air, thereby achieving heat dissipation or cooling of the lithium battery pack through the air duct or incoming flow of the nacelle.

[0122] Embodiment 1, embodiment 2, embodiment 3, or embodiment 4 can achieve the following beneficial effects:

[0123] In each embodiment, the electrical architecture, power architecture and thermal management architecture are collaboratively designed, which can not only realize the combination or hybrid power supply of hydrogen and lithium batteries through fuel cells and lithium batteries, but also realize the heat dissipation or cooling of the fuel cell system, lithium battery system and motor controller, thereby managing the heat generation of the fuel cell system, lithium battery system and motor controller, achieving zero carbon emissions, improving energy utilization, and improving electric propulsion effect and efficiency.

[0124] In each embodiment, the electric propulsion system is integrated into the aircraft nacelle, thereby becoming a new type of power system. Compared with traditional fuel power, it can achieve zero carbon emissions, and even if a failure occurs, it will not affect the passenger cabin, and it is highly safe.

[0125] In each embodiment, through the high-voltage and low-voltage electrical architecture design, high-voltage and low-voltage power supply modes can be provided, and high-voltage and low-voltage mixed power supply is realized. By controlling the first to fifth switch control units, a high-reliability high-voltage switch control circuit is formed. By using a separately set switch control device and a non-similar low-voltage power supply, the power supply reliability can be improved.

[0126] Centralized heat control is achieved through the thermal management system. In particular, thermal management systems with different architectures can be used according to the flight environment of the aircraft. For example, the thermal management system provided in Example 2 is more comprehensive and universal, and is suitable for use in various flight environments. The thermal management systems provided in Example 3 and Example 4 are particularly suitable for use in cold flight environments and humid and hot flight environments, respectively, and have a more streamlined architecture, stronger environmental targeting, and more flexible architecture selection.

[0127] With reference to Example 2 and Example 4, the phase change storage device can be used as a phase change refrigeration device, which absorbs the heat of the cooling medium through phase change, and can be used to dissipate heat from the first heat exchange device and / or the second heat exchange device and / or the third heat exchange device, thereby effectively improving the heat dissipation effect.

[0128] The thermal management system can reuse the valves or pumps of the BOP system, and different thermal management systems can be used for different flight environments, which is conducive to streamlining the system architecture and reducing weight.

[0129] The high-voltage control box of the lithium battery system is directly used in the electrical architecture to achieve energy management of the power supply network, which is conducive to streamlining the system architecture and reducing weight.

[0130] In each embodiment, the electric propulsion system is integrated into the aircraft nacelle, and the flow field in the nacelle is fully utilized for heat dissipation or cooling, which can improve the thermal management effect and efficiency, and reduce the complexity of the thermal management system, thereby achieving the effect of reducing costs and weight.

[0131] The above embodiments can be used in combination.

[0132] The above is only an embodiment of this specification and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A fuel cell-based electric propulsion system, characterized in that: The electric propulsion system includes a motor, a motor controller, a lithium battery system, a fuel cell system and a thermal management system; Wherein, the fuel cell system and the lithium battery system are used to power the motor controller; The motor controller is connected to the motor, and the motor controller is used to control the motor to output a specified power and speed, and the motor is used to drive the aircraft propulsion device; The thermal management system comprises: a first heat exchange device, for performing heat exchange with a component of the fuel cell system; A second heat exchange device, used for performing heat exchange with components of the lithium battery system; The third heat exchange device is used for performing heat exchange with the motor controller.

2. The electric propulsion system according to claim 1, characterized in that: The lithium battery system includes a lithium battery pack and a high-voltage control box, and the fuel cell system includes a fuel cell stack, a BOP system and a fuel cell controller; The output end of the BOP system is connected to the high-voltage control box; An energy management controller is provided in the high-voltage control box, and the energy management controller is connected to the fuel cell controller; The high voltage control box is connected to the motor controller.

3. The electric propulsion system according to claim 2, characterized in that: The electric propulsion system further includes a first switch control unit, a second switch control unit, a third switch control unit, a fourth switch control unit, and a fifth switch control unit; Wherein, the first switch control unit is connected to the positive electrode or negative electrode of the discharge resistor and the motor controller respectively; The second switch control unit is connected to the positive electrode of the BOP system and the bus bar in the high-voltage control box respectively; The third switch control unit is respectively connected to the pre-charging resistor and the bus bar in the high-voltage control box; The fourth switch control unit is connected to the positive electrode of the lithium battery pack and the bus bar in the high-voltage control box respectively; The fifth switch control unit is connected to the negative electrode of the lithium battery pack and the bus bar in the high-voltage control box respectively.

4. The electric propulsion system according to claim 3, characterized in that The energy management controller is used to control the opening and closing of the first to fifth switch control units.

5. The electric propulsion system according to claim 3 or 4, characterized in that: The drive circuits of the fourth switch control unit and the fifth switch control unit are connected to the switch control device, the energy management controller is connected to the switch control device, and the switch control device is connected to the low-voltage power supply output by the lithium battery system and / or the aircraft low-voltage power supply.

6. The electric propulsion system according to claim 1, characterized in that The thermal management system further includes a phase change storage, a fourth heat exchange device and a fifth heat exchange device; Among them, the fourth heat exchange device is used to perform heat exchange with the phase change storage; the first heat exchange device is connected to the fourth heat exchange device and the fifth heat exchange device through pipelines, the second heat exchange device is connected to the fourth heat exchange device and the fifth heat exchange device through pipelines, and the third heat exchange device is connected to the fourth heat exchange device and the fifth heat exchange device through pipelines.

7. The electric propulsion system according to claim 1, characterized in that The thermal management system further includes a sixth heat exchange device; Wherein, the sixth heat exchange device is used for heat exchange with air; the sixth heat exchange device is respectively connected with the first heat exchange device, the second heat exchange device and the third heat exchange device through pipelines.

8. The electric propulsion system according to claim 1, characterized in that The thermal management system further includes a phase change storage, a seventh heat exchange device and an eighth heat exchange device; Among them, the seventh heat exchange device is used to exchange heat with the phase change storage; the first heat exchange device is connected to the seventh heat exchange device and the eighth heat exchange device through pipelines, and the third heat exchange device is connected to the seventh heat exchange device and the eighth heat exchange device through pipelines.

9. The electric propulsion system according to claim 1, characterized in that The electric propulsion system further comprises a hydrogen storage device, which is used to supply hydrogen to the fuel cell system.

10. The electric propulsion system according to claim 1, characterized in that The electric propulsion system also includes a phase change refrigeration device, which is used to dissipate heat from the first heat exchange device and / or the second heat exchange device and / or the third heat exchange device.

Images