Superconducting hydrogen electric propulsion system with liquid hydrogen storage and liquid nitrogen refrigeration

Abstract

The application provides a superconducting hydrogen electric propulsion system with liquid hydrogen cold storage and liquid nitrogen refrigeration, and belongs to the technical field of electric propulsion. The system specifically comprises a liquid hydrogen storage tank, a hydrogen delivery pipeline, a liquid nitrogen storage tank, a liquid nitrogen delivery loop, a first heat exchanger and a heating device. The liquid hydrogen storage tank delivers hydrogen fuel to an engine through the hydrogen delivery pipeline. The heating device is used for heating liquid hydrogen to vaporize the liquid hydrogen. The hydrogen delivery pipeline between the liquid hydrogen storage tank and the heating device is connected to one channel in the first heat exchanger. The liquid nitrogen delivery loop comprises an output pipeline and a recovery pipeline. The output pipeline is connected to the outlet of the liquid nitrogen storage tank and the inlet of a cooling channel. The recovery pipeline is connected to the outlet of the cooling channel and the inlet of the liquid nitrogen storage tank. The recovery pipeline is connected to another channel in the first heat exchanger. Through the processing scheme, the safety factor of the superconducting hydrogen electric propulsion system is significantly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric propulsion, and in particular to a superconducting hydrogen electric propulsion system with liquid hydrogen cold storage and liquid nitrogen refrigeration. BACKGROUND

[0002] As a clean power, electric propulsion technology can be used in the fields of aviation, ships, automobiles, etc., and it is the development trend of future advanced power to realize energy saving and emission reduction, vibration reduction and noise reduction. However, at present, due to the low energy density of the battery and the small power of the electric propulsion, the endurance mileage and the load capacity of the electric propulsion technology powered by pure battery cannot meet the requirements of industrial use.

[0003] At present, the electric power of the electric propulsion system is mainly obtained by energy conversion of fuel oil or other clean fuels, and the power source of the electric propulsion system is formed by combining the on-board energy storage system, so as to improve the endurance mileage of the electric propulsion system. Among many fuel methods, the emission of liquid hydrogen as fuel is the lowest, so the hydrogen electric propulsion technology has broad prospects. In addition, the output power of the electric propulsion technology at room temperature is low, and the current loss in the electric circuit is large. When the electric circuit of the electric propulsion system is superconducting, the voltage level and the load capacity of the electric propulsion system can be greatly improved, and thus the output power can be improved, so that the electric propulsion system has the ability to serve large-scale transportation scenarios.

[0004] Some technologies propose to use liquid hydrogen as a refrigerant to realize superconducting of the electric circuit of the electric propulsion system, but this has significant safety problems. The superconducting electric circuit mainly includes a superconducting generator, a superconducting motor, a superconducting cable, and an external stainless steel shell for maintaining the low-temperature superconducting circuit. A large alternating current loss will be generated as the motor works, and an eddy current will be formed in the external shell. Since the chemical properties of liquid hydrogen are very active, it is easy to explode and burn when it comes into contact with electricity, which is a major hazard. SUMMARY

[0005] Therefore, the present application provides a superconducting hydrogen electric propulsion system with liquid hydrogen cold storage and liquid nitrogen refrigeration, which solves the problems in the prior art and significantly improves the safety factor of the superconducting hydrogen electric propulsion system.

[0006] The superconducting hydrogen electric propulsion system with liquid hydrogen cold storage and liquid nitrogen refrigeration provided by the present application adopts the following technical solution:

[0007] The superconducting hydrogen electric propulsion system with liquid hydrogen cold storage and liquid nitrogen refrigeration comprises an engine and an electric propulsion mechanism, the electric propulsion mechanism comprises a superconducting generator, a superconducting motor and a cooling channel, the engine drives the superconducting generator to generate electricity, the superconducting generator drives the superconducting motor to operate, the superconducting motor drives a load to operate, and the cooling channel provides a superconducting operating environment for the electric propulsion mechanism, and further comprises a liquid hydrogen storage tank, a hydrogen delivery pipeline, a liquid nitrogen storage tank, a liquid nitrogen delivery circuit, a first heat exchanger and a heating device.

[0008] The liquid hydrogen storage tank supplies hydrogen fuel to the engine through a hydrogen delivery pipeline, the heating device is used for heating liquid hydrogen to vaporize the liquid hydrogen, and the hydrogen delivery pipeline between the liquid hydrogen storage tank and the heating device is communicated with one channel in the first heat exchanger;

[0009] The liquid nitrogen delivery circuit comprises an output pipeline and a recovery pipeline, the output pipeline is communicated with the outlet of the liquid nitrogen storage tank and the inlet of the cooling channel, and the recovery pipeline is communicated with the outlet of the cooling channel and the recovery inlet of the liquid nitrogen storage tank, and the recovery pipeline is communicated with another channel in the first heat exchanger.

[0010] Optionally, the superconducting hydrogen electric propulsion system with liquid hydrogen cold storage and liquid nitrogen refrigeration further comprises a refrigeration assembly, the refrigeration assembly is used for maintaining liquid hydrogen in the liquid hydrogen storage tank at a first preset temperature, and the refrigeration assembly is further used for maintaining liquid nitrogen in the liquid nitrogen storage tank at a second preset temperature before the engine stops and the rotating speed reaches a target working state.

[0011] Optionally, the hydrogen delivery pipeline comprises a first branch pipeline, a second branch pipeline and a total delivery pipeline, the first branch pipeline and the second branch pipeline are both communicated with the inlet of the total delivery pipeline through the heating device, the total delivery pipeline delivers the vaporized hydrogen to the engine, the first branch pipeline between the heating device and the liquid hydrogen storage tank is communicated with the first heat exchanger;

[0012] The second heat exchanger is communicated with the second branch pipeline between the heating device and the liquid hydrogen storage tank, and the second heat exchanger heats liquid hydrogen in the second branch pipeline by using internal heat of the engine.

[0013] Optionally, the engine is a gas turbine engine.

[0014] Optionally, the second heat exchanger heats liquid hydrogen in the second branch pipeline by using heat of engine exhaust gas or heat of high-pressure compressor outlet gas.

[0015] Optionally, the superconducting hydrogen electric propulsion system with liquid hydrogen cold storage and liquid nitrogen refrigeration further comprises an energy storage assembly, the energy storage assembly is connected with an output electrode of the superconducting generator and is used for storing electric energy generated by the superconducting generator.

[0016] In summary, the present application has the following beneficial technical effects:

[0017] In the application, low-temperature liquid nitrogen is delivered to the cooling channel through a liquid nitrogen delivery pipeline to provide a high-temperature superconducting low-temperature environment for a superconducting generator, a superconducting motor and related superconducting cables. Liquid nitrogen is used as a superconducting medium to realize high-temperature superconductivity. The temperature of the cooled liquid nitrogen is raised by a recovery pipeline through a first heat exchanger and returned to a liquid nitrogen storage tank. In the first heat exchanger, the temperature of the heated nitrogen is lowered by liquid hydrogen cold energy, and the cooled liquid nitrogen is returned to the liquid nitrogen storage tank. The cooled liquid nitrogen is returned to the liquid nitrogen storage tank to provide the cooling channel. At the same time, the liquid hydrogen is heated in the first heat exchanger, which can reduce the energy consumption required for heating and vaporizing hydrogen by the heating device. In the whole process, liquid hydrogen is used as fuel to absorb heat and exchange heat with liquid nitrogen, thereby continuously ensuring the superconductivity of the electric propulsion mechanism by liquid nitrogen. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application, and all other drawings obtained by those of ordinary skill in the art without creative labor based on these drawings are within the scope of protection of the present application.

[0019] Figure 1 The principle block diagram of the superconducting hydrogen electric propulsion system of the liquid hydrogen and liquid nitrogen refrigeration embodiment of the present application.

[0020] The drawings are described as follows: 1, engine; 2, superconducting generator; 3, superconducting motor; 4, cooling channel; 5, liquid hydrogen storage tank; 51, first branch pipeline; 52, second branch pipeline; 53, total delivery pipeline; 6, liquid nitrogen storage tank; 61, output pipeline; 62, recovery pipeline; 7, first heat exchanger; 8, second heat exchanger; 9, heating device; 10, energy storage component; 11, propeller; 12, refrigeration component. DETAILED DESCRIPTION

[0021] The embodiments of the present application will be described in detail below with reference to the drawings.

[0022] The embodiments of the present application are described below through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the disclosure. Obviously, the described embodiments are only some of the embodiments of the present application, not all. The present application can also be implemented or applied by other different specific embodiments, and the details in the specification can be modified or changed based on different views and applications without departing from the spirit of the present application. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor are within the scope of protection of the present application.

[0023] It is to be understood that the embodiments described herein are for illustrative purposes and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application and scope of the appended claims. It is also to be understood that the various aspects described herein can be implemented in any number of ways, and that the embodiments described herein with respect to certain arrangements of components should be understood as merely illustrative as many modifications can be made without departing from the spirit and scope of the application. Accordingly, the application is not to be seen as being limited to the embodiments described herein, but is to be understood to include all variations falling within the scope of the appended claims.

[0024] It is also to be understood that the above-referenced elements of the figure shown in the following embodiments solely serve the purpose of illustrating the basic idea of the present application and that only components relevant to the present application are shown in the figure, not drawn according to the number, shape and size of the components at the time of actual implementation, and the shape, number and proportion of each component at the time of actual implementation can be a kind of arbitrary change, and the layout of its components can be more complex.

[0025] In addition, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, one skilled in the art will understand that the described aspects can be practiced without these specific details.

[0026] The embodiment of the present application provides a liquid hydrogen storage liquid nitrogen refrigeration superconducting hydrogen electric propulsion system.

[0027] As shown in the figure, Figure 1 A liquid hydrogen storage liquid nitrogen refrigeration superconducting hydrogen electric propulsion system includes an engine 1 and an electric propulsion mechanism, the electric propulsion mechanism includes a superconducting generator 2, a superconducting motor 3 and a cooling channel 4, the engine 1 drives the superconducting generator 2 to generate electricity, the superconducting generator 2 drives the superconducting motor 3 to operate, the superconducting motor 3 drives the load to operate, and the cooling channel 4 provides the temperature environment required for the superconducting operation of the electric propulsion mechanism. In the embodiment of the present application, the cooling channel 4 provides a low temperature environment for the superconducting generator 2, the superconducting motor 3 and the superconducting cable, and the cooling channel 4 covers the external area of the superconducting generator 2, the superconducting motor 3 and the related superconducting cable. Among them, the superconducting generator 2 and the superconducting motor 3 are prior art, and they are not the innovation point of the present application, so their specific structure is not described here. The engine is a hydrogen fuel engine.

[0028] The liquid hydrogen storage liquid nitrogen refrigeration superconducting hydrogen electric propulsion system of the present application further comprises a liquid hydrogen storage tank 5, a hydrogen delivery pipeline, a liquid nitrogen storage tank 6, a liquid nitrogen delivery circuit, a first heat exchanger 7 and a heating device 9.

[0029] The liquid hydrogen storage tank 5 supplies hydrogen fuel to the engine 1 through a hydrogen delivery pipeline, the heating device 9 is used for heating liquid hydrogen to vaporize the liquid hydrogen, and the vaporized hydrogen is supplied to the engine 1. The hydrogen delivery pipeline between the liquid hydrogen storage tank 5 and the heating device 9 is communicated with one channel in the first heat exchanger 7. The heating device 9 provides heat to ensure the vaporization of the liquid hydrogen.

[0030] The liquid nitrogen delivery circuit includes an output pipeline 61 and a recovery pipeline 62. The output pipeline 61 is communicated with the outlet of the liquid nitrogen storage tank 6 and the inlet of the cooling channel 4. The recovery pipeline 62 is communicated with the outlet of the cooling channel 4 and the recovery inlet of the liquid nitrogen storage tank 6. The recovery pipeline 62 is communicated with another channel in the first heat exchanger 7.

[0031] In this application, the low-temperature liquid nitrogen is delivered into the cooling channel 4 through the delivery pipeline to provide a high-temperature superconducting low-temperature environment for the superconducting generator 2, the superconducting motor 3 and the related superconducting cable. Liquid nitrogen is used as a superconducting medium to realize high-temperature superconductivity. The temperature of the cooled liquid nitrogen is raised and returned to the liquid nitrogen storage tank through the recovery pipeline 62 and the first heat exchanger 7. In the first heat exchanger 7, the temperature of the raised nitrogen is lowered by using the cold energy of the liquid hydrogen. The cooled liquid nitrogen is returned to the liquid nitrogen storage tank 6 and reenters the cooling channel 4. At the same time, the liquid hydrogen is heated in the first heat exchanger 7, which can reduce the energy consumption required for heating and vaporizing hydrogen by the heating device 9. In the whole process, the liquid hydrogen is used as fuel to absorb heat for vaporization and exchange heat with the liquid nitrogen, so as to continuously ensure the superconductivity of the electric propulsion mechanism by the liquid nitrogen.

[0032] Compared with the pure liquid hydrogen superconducting hydrogen electric propulsion system, the refrigeration cost and material cost are reduced, the additional mass of the refrigeration system is smaller, and the possibility of explosion caused by the reaction of eddy current or leakage current with liquid hydrogen is avoided, so that the safety factor of the superconducting hydrogen electric propulsion system is significantly improved. Compared with the traditional liquid nitrogen superconducting method, the hydrogen electric propulsion technology significantly reduces carbon emissions, and theoretically realizes zero emission. Compared with the traditional electric propulsion technology, the output power of the low-temperature cooling circuit is improved, and the carrying efficiency is greatly improved, which has a significant advantage in energy saving and emission reduction, cost reduction and efficiency improvement. The hydrogen electric propulsion technology with liquid hydrogen cold storage and liquid nitrogen superconductivity can realize pollution-free zero emission, safe superconductivity, large output power, light weight of the refrigeration system, low refrigeration cost and low material cost, and meets the application requirements of future power for energy saving and emission reduction, cost reduction and efficiency improvement.

[0033] In one embodiment, the engine 1 is a gas turbine engine. The superconducting hydrogen electric propulsion system with liquid hydrogen cold storage and liquid nitrogen refrigeration further includes an energy storage assembly 10 connected to the output electrode of the superconducting generator 2 for storing the electric energy generated by the superconducting generator 2.

[0034] The superconducting hydrogen electric propulsion system of liquid hydrogen storage and liquid nitrogen refrigeration further comprises a refrigeration assembly 12 for maintaining the liquid hydrogen in the liquid hydrogen storage tank 5 at a first preset temperature, and for maintaining the liquid nitrogen in the liquid nitrogen storage tank 6 at a second preset temperature before the engine 1 is stopped and the rotating speed reaches a target working state.

[0035] The hydrogen delivery pipeline comprises a first branch pipeline 51, a second branch pipeline 52 and a total delivery pipeline 53, the first branch pipeline 51 and the second branch pipeline 52 are both connected to the inlet of the total delivery pipeline 53 through the heating device 9, the total delivery pipeline 53 delivers the vaporized hydrogen to the engine 1, the first branch pipeline 51 between the heating device 9 and the liquid hydrogen storage tank 5 is connected to the first heat exchanger 7, the second branch pipeline 52 between the heating device 9 and the liquid hydrogen storage tank 5 is connected to the second heat exchanger 8, and the second heat exchanger 8 heats the liquid hydrogen in the second branch pipeline 52 by using the internal heat of the engine 1.

[0036] In the embodiment of the application, the operation of each component of the system under different states of the engine 1 is as follows.

[0037] When the engine 1 is in the parking standby state, the refrigeration assembly 12 provides refrigeration capacity for the liquid hydrogen storage tank 5 and the liquid nitrogen storage tank 6, at this time, the liquid hydrogen storage tank 5 does not output liquid hydrogen, and the state of the liquid nitrogen in the liquid nitrogen storage tank 6 is maintained by the refrigeration assembly 12, when parking standby, the heating device 9 is in standby state, the superconducting generator 2 and the superconducting motor 3 are also in standby state, the heat generation is less, and the system does not need too much refrigeration capacity to maintain superconducting, and the lower liquid nitrogen flow rate supplied by the liquid nitrogen storage tank 6 to the cooling channel 4 can realize the superconducting of the electric propulsion mechanism.

[0038] The process from the parking standby state to the starting state of the engine 1: when the engine 1 is in the parking standby state, the engine 1 is driven to reach the self-sustaining rotating speed by the auxiliary starter, and the heating device 9 is started to reach the temperature capable of vaporizing the liquid hydrogen. When the electric propulsion mechanism obtains the engine starting instruction, the liquid hydrogen is supplied from the liquid hydrogen storage tank 5 to the second heat exchanger 8 for the heat exchange between the liquid hydrogen and the gas, and to the first heat exchanger 7 for the heat exchange between the liquid nitrogen and the liquid hydrogen through the first branch pipeline 51, the liquid hydrogen flowing through the first heat exchanger 7 and the second heat exchanger 8 is collected to the heating device 9 to absorb heat to vaporize the liquid hydrogen, and the vaporized liquid hydrogen is sprayed into the combustion chamber of the engine 1 for combustion. The engine 1 outputs mechanical energy to the superconducting generator 2 to generate electric energy, part of the electric energy is stored in the electric energy storage assembly 10, and part of the electric energy is supplied to the superconducting motor 3 to drive the load to work and generate the power of the hydrogen electric propulsion system. The load can be the propeller 11.

[0039] Since the liquid hydrogen cools the liquid nitrogen in the liquid nitrogen recovery pipeline 62, the refrigeration amount provided by the refrigeration assembly 12 to the liquid nitrogen storage tank 6 can be controlled and reduced to prevent the liquid nitrogen from solidifying in the liquid nitrogen storage tank 6 and the pipeline through which the liquid nitrogen flows.

[0040] Process of the engine reaching the set target working state:

[0041] According to the set engine target working state, the liquid hydrogen flow provided by the liquid hydrogen storage tank 5 is continuously increased to match the current engine 1 speed, and the AC / DC loss of the electric propulsion mechanism is increased. The liquid nitrogen flow provided by the liquid nitrogen storage tank to the cooling channel 4 is also increased to maintain the superconducting state of the electric propulsion mechanism.

[0042] As the engine 1 speed increases, the gas temperature at the engine outlet increases, and the heat of the high-temperature gas is used to heat the liquid hydrogen in the second heat exchanger 8. This operation improves the overall stealth performance of the hydrogen electric propulsion system and reduces the energy consumption of the heating device 9, which reduces the auxiliary heating energy consumption and saves the cost of liquid hydrogen vaporization.

[0043] At this time, since the supply amount of liquid hydrogen is increased, the liquid hydrogen in the first heat exchanger 7 can sufficiently cool the liquid nitrogen to maintain the low-temperature state of the liquid nitrogen, and the refrigeration assembly 12 does not need to provide refrigeration to the liquid nitrogen storage tank 6.

[0044] Process of the engine from braking deceleration to parking state:

[0045] According to the braking and parking instructions received by the engine, the liquid hydrogen storage tank 5 stops supplying hydrogen, and the remaining mechanical energy of the engine 1 is converted into electrical energy by the superconducting generator 2. This process stops providing liquid nitrogen to the cooling channel 4, and there is no need to maintain the superconducting state of the electric propulsion mechanism. The vaporized liquid nitrogen is discharged through the overflow device. When the hydrogen electric propulsion system is completely parked, the overflow device for liquid nitrogen vaporization is closed, and the next parking standby state is entered.

[0046] In one embodiment, the second heat exchanger 8 uses the heat of the engine exhaust gas or the heat of the high-pressure compressor outlet gas to heat the liquid hydrogen in the second branch pipeline 52. Specifically, an air bleeding pipeline is arranged at the outlet of the high-pressure compressor, one channel of the second heat exchanger 8 is connected to the air bleeding pipeline, and the other channel of the second heat exchanger 8 is connected to the second branch pipeline 52. The high-temperature compressed air at the outlet of the high-pressure compressor is used to heat the liquid hydrogen in the second heat exchanger 8.

[0047] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto. Any changes or replacements within the technical scope disclosed in the present application can be easily thought of by those skilled in the art, and should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A superconducting hydrogen electric propulsion system with liquid hydrogen storage and liquid nitrogen cooling, comprising an engine (1) and an electric propulsion mechanism, the electric propulsion mechanism comprising a superconducting generator (2), a superconducting motor (3), and a cooling channel (4), wherein the engine (1) drives the superconducting generator (2) to generate electricity, the superconducting generator (2) drives the superconducting motor (3) to operate, the superconducting motor (3) drives the load to operate, and the cooling channel (4) provides a superconducting operating environment for the electric propulsion mechanism, characterized in that, It also includes a liquid hydrogen storage tank (5), a hydrogen delivery pipeline, a liquid nitrogen storage tank (6), a liquid nitrogen delivery loop, a first heat exchanger (7), and a heating device (9). The engine (1) is a gas turbine engine. The hydrogen delivery pipeline includes a first branch pipeline (51), a second branch pipeline (52), and a main delivery pipeline (53). The first branch pipeline (51) and the second branch pipeline (52) are both connected to the inlet of the main delivery pipeline (53) through the heating device (9). The main delivery pipeline (53) delivers the vaporized hydrogen to the engine (1). The first branch pipeline (51) between the heating device (9) and the liquid hydrogen storage tank (5) is connected to the first heat exchanger (7). A second heat exchanger (8) is connected to the second branch pipe (52) between the heating device (9) and the liquid hydrogen storage tank (5). The second heat exchanger (8) uses the internal heat of the engine (1) to heat the liquid hydrogen in the second branch pipe (52). The liquid hydrogen storage tank (5) supplies hydrogen fuel to the engine (1) through a hydrogen delivery pipeline. The heating device (9) is used to heat the liquid hydrogen to vaporize it. The hydrogen delivery pipeline between the liquid hydrogen storage tank (5) and the heating device (9) is connected to a channel in the first heat exchanger (7). The liquid nitrogen delivery circuit includes an output pipeline (61) and a recovery pipeline (62). The output pipeline (61) is connected to the outlet of the liquid nitrogen storage tank (6) and the inlet of the cooling channel (4). The recovery pipeline (62) is connected to the outlet of the cooling channel (4) and the recovery inlet of the liquid nitrogen storage tank (6). The recovery pipeline (62) is connected to another channel in the first heat exchanger (7). The superconducting hydrogen electric propulsion system with liquid hydrogen storage and liquid nitrogen cooling also includes a cooling component (12), which is used to maintain the liquid hydrogen in the liquid hydrogen storage tank (5) at a first preset temperature, and the cooling component (12) is also used to maintain the liquid nitrogen in the liquid nitrogen storage tank (6) at a second preset temperature before the engine (1) stops and the speed reaches the target working state. When the engine (1) is in a stopped standby state, the liquid nitrogen in the liquid nitrogen storage tank (6) is maintained by the refrigeration component (12); During the process of the engine (1) going from standby to start-up, the cooling capacity provided by the cooling component (12) to the liquid nitrogen storage tank (6) is reduced; Once the engine reaches the set target operating state, the refrigeration component (12) stops providing cooling to the liquid nitrogen storage tank (6).

2. The superconducting hydrogen electric propulsion system with liquid hydrogen storage and liquid nitrogen cooling according to claim 1, characterized in that, The second heat exchanger (8) uses the heat from the exhaust gas of the engine (1) or the heat from the outlet gas of the high-pressure compressor to heat the liquid hydrogen in the second branch pipe (52).

3. The superconducting hydrogen electric propulsion system with liquid hydrogen storage and liquid nitrogen cooling according to claim 1, characterized in that, The superconducting hydrogen electric propulsion system with liquid hydrogen storage and liquid nitrogen cooling also includes an energy storage component (10), which is connected to the output electrode of the superconducting generator (2) and is used to store the electrical energy generated by the superconducting generator (2).

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