Liquid hydrogen electric drive propelling system

Abstract

The utility model provides a liquid hydrogen electric drive propulsion system, which comprises a liquid hydrogen storage tank, a hydrogen fuel cell stack, an electric power conversion unit, a superconducting motor and an executive component, the hydrogen fuel cell stack is arranged outside the liquid hydrogen storage tank and is connected with the liquid hydrogen storage tank through a pipeline, and the liquid hydrogen electric drive propulsion system is characterized in that the electric power conversion unit and the superconducting motor are arranged in the liquid hydrogen storage tank; the electric power conversion unit converts current generated by the hydrogen fuel cell stack and then conveys the current to the superconducting motor, and the output end of the superconducting motor penetrates through the liquid hydrogen storage tank and is in driving connection with the execution element; the power conversion unit and the superconducting motor are directly arranged in the liquid hydrogen storage tank, so that high system integration is realized, the pipeline complexity and leakage risk are reduced, and the reliability and safety of the system are improved; and compared with a high-temperature superconducting motor in the prior art, the superconducting motor arranged in the liquid hydrogen storage tank can make full use of the low-temperature characteristic of liquid hydrogen, the performance of superconducting materials is improved, and then the output power and efficiency of the motor are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of hydrogen energy, and particularly relates to a liquid hydrogen electric drive propulsion system. Background Technique

[0002] The research on power propulsion technology in various countries around the world is developing towards high power, low noise, and low carbon emissions. Classified by power source, the currently common power propulsion systems mainly include fuel power propulsion systems, lithium battery propulsion systems, nuclear power propulsion systems, hybrid power propulsion systems, etc. Fuel power is the most common power type in the market at present. It mainly relies on fossil fuels, namely gasoline or diesel, as the fuel for internal combustion engines to drive. This power type has mature technology and convenient refueling, but the exhaust gas emitted will cause certain pollution to the environment. Compared with traditional propulsion systems, the lithium battery propulsion system has the characteristics of good economy, flexible operation, high safety, low vibration, and high reliability. With the rapid development of power electronics technology and the increasing energy crisis, the replacement of traditional diesel engine propulsion by lithium battery propulsion has become an irresistible trend. Although lithium battery propulsion technology has great advantages in terms of mobility, reliability, operation efficiency, layout flexibility, economy, and easy maintenance, it still needs to be further improved in terms of endurance, charging speed, service life, and comprehensive power management technology. The nuclear power propulsion system uses nuclear reactions as the main functional device, which is not specifically for the power of ships, but can also be the energy source for land and spacecraft. It has extremely high energy density. Many submarines and icebreakers use nuclear reactors as their power devices. The attempt to nuclear powerize transportation tools has been most successful in ship applications for three main reasons. First, ships are relatively large in volume and can carry reactors and related equipment, maintenance personnel, etc. Second, the huge energy demand of ships also matches the large output of nuclear power. Third, it is very convenient to obtain the cooling source of nuclear power facilities. Considering that ships are water transportation tools, the water they rely on is inexhaustible. However, it has the characteristics of high technical difficulty, complex structure system, and extremely high potential safety level risks.

[0003] It should be noted that for the above propulsion systems, the energy consumption of motors and cables is the main reason hindering their high-power development, and the use of fossil fuels, nuclear fuels, and electrolytes is the main reason hindering their low-carbon development. Therefore, the utility model proposes a liquid hydrogen-based electric drive propulsion system, which uses liquid hydrogen as an alternative fuel. Its cold energy provides a superconducting environment, and the performance of the propulsion system is improved through superconducting motors and superconducting cables, aiming to achieve the development goals of high power, low noise, and low carbon emissions in the power propulsion systems of aviation, rail transit, and ships.

[0004] The liquid hydrogen electric drive propulsion system consists of a liquid hydrogen storage tank, a hydrogen fuel cell, and a superconducting motor. Liquid hydrogen is pumped out of the storage tank, vaporizes after flowing through the superconducting motor for heat exchange, which can not only provide the hydrogen fuel required by the fuel cell, but also the large amount of heat absorption during its vaporization process can be used to form the low-temperature environment required for superconducting materials. The implementation solution most similar to the present utility model is a liquid hydrogen high-temperature superconducting motor all-electric propulsion system and a superconducting motor fuel cell power system using liquid hydrogen. The system stores liquid hydrogen by a liquid hydrogen storage and transportation module and transports the liquid hydrogen to a power propulsion module, a hydrogen-air fuel cell power generation module, and an external superconducting cable power transmission and transformation module for cooling to ensure the working performance of each module. After the liquid hydrogen cools each module, it enters a heat exchanger for heat exchange to form normal-temperature hydrogen and is transported to the hydrogen-air fuel cell power generation module as fuel, generates electricity through the chemical reaction of hydrogen and air, and is supplied to the power propulsion module through a superconducting cable for power supply.

[0005] The prior art has the following disadvantages:

[0006] 1. The superconducting motor used is a high-temperature superconducting motor, and its operating environment temperature is 138K. This is because the integration degree of the existing liquid hydrogen storage tank and the superconducting motor is not high, resulting in the only option of using a high-temperature superconducting motor.

[0007] 2. The low integration degree of the liquid hydrogen storage tank and the superconducting motor leads to the dependence on a heat exchanger for the temperature rise of liquid hydrogen and the temperature drop of the superconducting motor.

[0008] 3. The leakage risk brought by the vaporization process of liquid hydrogen flowing in the pipeline between the low-temperature storage tank and the superconducting motor module is the main risk source of the liquid hydrogen electric drive propulsion system. In addition, the liquid hydrogen flow pipeline is a low-temperature vacuum pipeline, with high cost and complex pipeline.

[0009] 4. The system generates thrust completely through the vaporization of liquid hydrogen to fuel cell power generation, without considering the situation of insufficient power supply or excessive power supply.

[0010] 5. The existing system includes a heat exchanger module. Summary of the Utility Model

[0011] The purpose of the present utility model is to provide a liquid hydrogen electric drive propulsion system with high integration degree to solve the problems existing in the prior art.

[0012] To solve the above technical problems, the present utility model provides a liquid hydrogen electric drive propulsion system, which includes: a liquid hydrogen storage tank, a hydrogen fuel cell stack, a power conversion unit, a superconducting motor, and an actuator. The hydrogen fuel cell stack is arranged outside the liquid hydrogen storage tank and is connected to the liquid hydrogen storage tank through a pipeline. The power conversion unit and the superconducting motor are arranged inside the liquid hydrogen storage tank to directly exchange heat with the liquid hydrogen in the storage tank. The power conversion unit converts the current generated by the hydrogen fuel cell stack and then transports it to the superconducting motor. The output end of the superconducting motor passes through the liquid hydrogen storage tank and is drivingly connected to the actuator.

[0013] Furthermore, the superconducting motor is a cryogenic superconducting motor, and the operating ambient temperature of the cryogenic superconducting motor is 35K.

[0014] Furthermore, the power conversion unit includes a DC / DC power converter disposed within the liquid hydrogen storage tank, and the DC / DC power converter is electrically connected to the hydrogen fuel cell stack.

[0015] Furthermore, the power conversion unit further includes a DC / AC inverter disposed within the liquid hydrogen storage tank, and the current generated by the hydrogen fuel cell stack is converted by the DC / DC power converter and the DC / AC inverter and then delivered to the superconducting motor.

[0016] Furthermore, an energy storage unit is further included. The energy storage unit has an input end and an output end. The hydrogen fuel cell stack is electrically connected to the input end of the energy storage unit, and the power conversion unit is electrically connected to the output end of the energy storage unit.

[0017] Furthermore, the energy storage unit is a lithium battery module.

[0018] Furthermore, a self-pressurizing module is further included. The self-pressurizing module is disposed outside the liquid hydrogen storage tank and is connected to the liquid hydrogen storage tank through a pipeline.

[0019] Furthermore, the hydrogen fuel cell stack is connected to the DC / DC power converter through a superconducting cable.

[0020] Furthermore, the energy storage unit is electrically connected to the power conversion unit through a superconducting cable.

[0021] Furthermore, the execution unit is a propeller fan.

[0022] As can be seen from the above technical solutions, the beneficial effects of the present utility model are as follows: By directly disposing the power conversion unit and the superconducting motor within the liquid hydrogen storage tank, a high degree of system integration is achieved, reducing pipeline complexity and leakage risks, improving the reliability and safety of the system, and the superconducting motor disposed within the liquid hydrogen storage tank can make better use of the low-temperature characteristics of liquid hydrogen than the high-temperature superconducting motor in the prior art, enhancing the performance of the superconducting material, thereby increasing the output power and efficiency of the motor. Description of the Drawings

[0023] Figure 1 is a schematic diagram of the liquid hydrogen electric drive propulsion system provided by the present application.

[0024] Explanation of the reference numerals in the drawings is as follows: 1. Air inlet pipeline and valve; 2. Fuel cell product water outlet pipeline and valve; 3. Hydrogen fuel cell stack; 4. Lithium battery module; 5. Liquid hydrogen storage tank; 6. Self-pressurizing module; 7. Hydrogen supply pipeline and valve; 8. DC / DC power converter; 9. DC / AC inverter; 10. Superconducting motor; 11. Propeller fan; 12. Self-relief module. Detailed implementation manners

[0025] Typical implementation manners embodying the features and advantages of the present utility model will be described in detail in the following description. It should be understood that the present utility model can have various variations in different implementation manners, all of which do not depart from the scope of the present utility model, and the descriptions and illustrations therein are essentially for illustrative purposes rather than for limiting the present utility model.

[0026] In the description of the present application, it should be understood that the orientation or positional relationship indicated by terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation of the present application. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present application, "a plurality" means two or more, unless otherwise specifically defined.

[0027] To further illustrate the principle and structure of the present utility model, the preferred embodiments of the present utility model will be described in detail with reference to the accompanying drawings.

[0028] Please refer to Figure 1 , a liquid hydrogen electric drive propulsion system provided for this embodiment, including an air inlet pipeline and valve 1, a fuel cell product water outlet pipeline and valve 2, a hydrogen fuel cell stack 3, a lithium battery module 4, a liquid hydrogen storage tank 5, a self-pressurizing module 6 of the liquid hydrogen storage tank 5, a hydrogen supply pipeline and valve 7, a power conversion unit, a DC / DC power converter 8, a DC / AC inverter 9, a superconducting motor 10, an actuator, and a self-pressure relief module 12 of the liquid hydrogen storage tank 5.

[0029] The liquid hydrogen electric drive propulsion system provided by the present utility model is applicable to aircraft / ship / vehicle propulsion. The aircraft / ship / vehicle air supply module is connected to the hydrogen fuel cell stack 3 through the air inlet pipeline, and its flow rate is adjusted and controlled by the valve group on the pipeline.

[0030] The product water generated by the chemical reaction of hydrogen and air inside the hydrogen fuel cell stack 3 is discharged through the fuel cell product water outlet, and the diversion mode of the product water is adjusted and controlled by the valve group on the pipeline. The product water can be directly discharged or recycled for use in the aircraft / ship / vehicle water supply system.

[0031] The gas-phase outlet of the hydrogen fuel cell stack 3 is connected to the liquid hydrogen storage tank 5 through a pipeline. The liquid hydrogen storage tank 5 supplies hydrogen to the fuel cell stack to provide the hydrogen required for the internal chemical reaction of the fuel cell. The supply flow rate is controlled and adjusted by a valve.

[0032] Furthermore, the hydrogen fuel cell stack 3 and the lithium battery module 4 are connected by ordinary cables. The lithium battery module 4 plays a role in short-term storage and release of electric energy. This module can store electric energy when the liquid hydrogen vaporizes to an excessive amount for the hydrogen fuel cell to generate electricity and supply power, and release electric energy when the liquid hydrogen vaporizes to an insufficient amount for the hydrogen fuel cell to generate electricity and supply power, so as to achieve the purpose of maintaining stable thrust.

[0033] The power conversion unit is used to convert the current generated by the hydrogen fuel cell stack 3 so that the current meets the operating requirements of the superconducting motor 10.

[0034] Furthermore, the power conversion unit includes a DC / DC power converter 8 and a DC / AC inverter 9.

[0035] Furthermore, the fuel cell stack is connected to the DC / DC power converter 8 through a superconducting cable. The electric power generated by the fuel cell stack is transmitted to the power converter 8 through the superconducting cable and drives the superconducting motor 10 after passing through the DC / AC inverter 9.

[0036] Furthermore, the lithium battery module 4 is connected to the DC / DC power converter 8 through a superconducting cable. The electric power stored in the lithium battery is transmitted to the power converter 8 through the superconducting cable and drives the superconducting motor 10 after passing through the DC / AC inverter 9.

[0037] Furthermore, the output end of the cryogenic superconducting motor 10 passes through the liquid hydrogen storage tank 5 and is connected to the actuator. A bearing is provided between the output end of the cryogenic superconducting motor 10 and the liquid hydrogen storage tank 5; in this embodiment, the actuator is a propeller fan 11.

[0038] Furthermore, the housings of the above-mentioned DC / DC power converter 8, DC / AC inverter 9 and superconducting motor 10 are protected by helium. The whole is placed inside the liquid hydrogen storage tank 5. If the liquid hydrogen directly contacts the housings of the power conversion unit and the motor housing, it will cause too large a temperature gradient of the housing; adding a layer of helium protection is to reduce the stress intensity of the housing, so as to better protect the internal power conversion unit and the motor.

[0039] Furthermore, the liquid hydrogen storage tank 5 includes a self-pressurizing module 6 and a self-relieving module 12. The self-pressurizing module 6 vaporizes part of the liquid hydrogen through an external vaporizer connected to the pipeline of the liquid hydrogen storage tank 5 to achieve the pressurization target, and the vaporization amount is controlled by the valve on the inlet pipeline of the vaporizer. The self-relieving module 12 is realized by discharging the hydrogen inside the liquid hydrogen storage tank 5. The gaseous hydrogen can be directly discharged or recycled for the fuel gas supply system of machines / ships / vehicles.

[0040] The liquid hydrogen storage tank 5 stores liquid hydrogen, and the liquid hydrogen storage tank 5 is airtight, vacuum and adiabatic. The temperature of the liquid hydrogen is about 20K. The cold energy of the liquid hydrogen can keep the superconducting motor 10 and the superconducting cable in the superconducting state, greatly reducing the loss during power transmission and the loss of the motor.

[0041] The working process is as follows: When in use, the hydrogen fuel cell stack 3, the lithium battery module 4, the liquid hydrogen storage tank 5, the power converter 8, the inverter 9, the superconducting motor 10, the propeller fan 11, the self-pressurizing module 6 and the self-pressure-relieving module 12 are arranged according to Figure 1 the connection method shown. The liquid hydrogen storage tank 5 stores a sufficient amount of liquid hydrogen. The heat generated during the operation of the motor causes the liquid hydrogen to form a large-volume boiling state to generate hydrogen; at the same time, due to the inevitable heat leakage of the liquid hydrogen storage tank 5, a certain amount of hydrogen will also be generated; in addition, when the gasification amount of the liquid hydrogen is insufficient, the external self-pressurizing module 6 can be used to accelerate the gasification of the liquid hydrogen. These three parts of hydrogen enter the hydrogen fuel cell stack 3 module through the gas-phase outlet and serve as one of the reactants for chemical reactions to generate electric energy. Air enters the hydrogen fuel cell stack 3 through the machine / ship / vehicle-mounted air supply module and serves as another reactant for chemical reactions. Inside the hydrogen fuel cell, hydrogen reacts with oxygen in the air to supply electric energy, and the product water can be directly discharged or recycled for use in the machine / ship / vehicle-mounted water supply system. The electric energy generated by the hydrogen fuel cell stack 3 is combined with the lithium battery module 4 to jointly supply the superconducting motor 10, and the propeller fan 11 is driven to rotate through the transmission shaft to generate thrust.

[0042] By directly arranging the power conversion unit and the superconducting motor inside the liquid hydrogen storage tank, the present utility model realizes a high degree of system integration, reduces the pipeline complexity and leakage risk, improves the reliability and safety of the system, and the superconducting motor arranged inside the liquid hydrogen storage tank can make better use of the low-temperature characteristics of the liquid hydrogen than the high-temperature superconducting motor in the prior art, improving the performance of the superconducting material and facilitating the maintenance of its superconducting state, thereby improving the output power and efficiency of the motor; it also omits the heat exchanger module in the prior art, simplifies the system structure, reduces the system cost and maintenance difficulty.

[0043] Although the present utility model has been described with reference to several typical embodiments, it should be understood that the terms used are illustrative and exemplary rather than restrictive. Since the present utility model can be embodied in many forms without departing from the spirit or essence of the utility model, it should be understood that the above embodiments are not limited to any of the foregoing details, but should be broadly construed within the spirit and scope defined by the appended claims. Therefore, all changes and modifications falling within the scope of the claims or their equivalents should be covered by the appended claims.

Claims

1. A liquid hydrogen electric drive propulsion system, comprising a liquid hydrogen storage tank, a hydrogen fuel cell stack, a power conversion unit, a superconducting motor, and an actuator. The hydrogen fuel cell stack is disposed outside the liquid hydrogen storage tank and is connected to the liquid hydrogen storage tank through a pipeline. It is characterized in that, The power conversion unit and the superconducting motor are arranged inside the liquid hydrogen storage tank to directly exchange heat with the liquid hydrogen inside the tank. The power conversion unit converts the current generated by the hydrogen fuel cell stack and then transmits it to the superconducting motor. The output end of the superconducting motor passes through the liquid hydrogen storage tank and is drivingly connected to the actuator.

2. The liquid hydrogen electric drive propulsion system according to claim 1, characterized in that, The superconducting motor is a cryogenic superconducting motor, and the operating ambient temperature of the cryogenic superconducting motor is 35K.

3. The liquid hydrogen electric drive propulsion system according to claim 1, characterized in that, The power conversion unit includes a DC / DC power converter arranged inside the liquid hydrogen storage tank, and the DC / DC power converter is electrically connected to the hydrogen fuel cell stack.

4. The liquid hydrogen electric drive propulsion system according to claim 3, characterized in that The power conversion unit further includes a DC / AC inverter arranged inside the liquid hydrogen storage tank. The current generated by the hydrogen fuel cell stack is converted by the DC / DC power converter and the DC / AC inverter and then transmitted to the superconducting motor.

5. The liquid hydrogen electric drive propulsion system according to claim 1, characterized in that, It further includes an energy storage unit which has an input end and an output end. The hydrogen fuel cell stack is electrically connected to the input end of the energy storage unit, and the power conversion unit is electrically connected to the output end of the energy storage unit.

6. The liquid hydrogen electric drive propulsion system according to claim 5, wherein, The energy storage unit is a lithium battery module.

7. The liquid hydrogen electric drive propulsion system according to claim 1, characterized in that, It further includes a self-pressurizing module which is arranged outside the liquid hydrogen storage tank and is connected to the liquid hydrogen storage tank through a pipeline.

8. The liquid hydrogen electric drive propulsion system according to claim 3, characterized in that, The hydrogen fuel cell stack is connected to the DC / DC power converter through a superconducting cable.

9. The liquid hydrogen electric drive propulsion system according to claim 5, characterized in that, The energy storage unit is electrically connected to the power conversion unit through a superconducting cable.

10. The liquid hydrogen electric drive propulsion system according to claim 4, characterized in that The actuator is a propeller fan.

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