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

Abstract

The invention provides a liquid hydrogen cold storage and liquid nitrogen refrigeration superconducting hydrogen electric propulsion system, which belongs to the technical field of electric propulsion and specifically comprises a liquid hydrogen storage tank, a hydrogen conveying pipeline, a liquid nitrogen storage tank, a liquid nitrogen conveying loop, a first heat exchanger and a heating device. The liquid hydrogen storage tank conveys hydrogen fuel to the engine through the hydrogen conveying pipeline, the heating device is used for heating liquid hydrogen to vaporize the liquid hydrogen, and the hydrogen conveying pipeline between the liquid hydrogen storage tank and the heating device is communicated with one channel in the first heat exchanger; the liquid nitrogen conveying loop comprises an output pipeline and a recovery pipeline, the output pipeline communicates with an outlet of the liquid nitrogen storage tank and an inlet of the cooling channel, the recovery pipeline communicates with an outlet of the cooling channel and a recovery inlet of the liquid nitrogen storage tank, and the recovery pipeline communicates with the other channel in the first heat exchanger. According to the treatment scheme, the safety coefficient of the superconducting hydrogen electric propulsion system is remarkably 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 Art

[0002] Electric propulsion technology, a clean power source, can be used in aviation, shipping, automotive, and other fields. It represents a future trend in advanced propulsion technologies for energy conservation, emission reduction, vibration reduction, and noise reduction. However, currently, due to limitations such as low battery energy density and low electric propulsion power, the range and payload of purely battery-powered electric propulsion technology fall far short of industrial application requirements.

[0003] At present, the power of electric propulsion systems mostly relies on fuel oil or other clean fuels to obtain electricity through energy conversion, and is combined with an onboard energy storage system to form the power source of the electric propulsion system, thereby increasing the cruising range of the electric propulsion system. Among them, liquid hydrogen has the lowest emissions among the many fuel methods, making hydrogen-electric propulsion technology have broad prospects. In addition, the output power of electric propulsion technology at room temperature is low, and the current loss in the electrical circuit is large. When the electrical circuit of the electric propulsion system is superconducting, the voltage level and current carrying capacity of the electric propulsion system can be greatly improved, thereby increasing the output power, enabling it to serve large-scale transportation demand scenarios.

[0004] Some technologies have proposed using liquid hydrogen as a refrigerant to achieve superconductivity in the electrical circuit of an electric propulsion system, but this presents significant safety concerns. The superconducting gas circuit primarily consists of a superconducting generator, a superconducting motor, superconducting cables, and an outer stainless steel casing that maintains the low-temperature superconducting circuit. As the motor operates, significant AC losses are generated, and eddy currents form in the outer casing. Liquid hydrogen is chemically reactive, and exposure to electricity can easily lead to explosions and deflagrations, creating significant risks. Summary of the Invention

[0005] In view of this, 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 existing technology and significantly improves the safety factor of the superconducting hydrogen-electric propulsion system.

[0006] The present application provides a superconducting hydrogen electric propulsion system with liquid hydrogen cold storage and liquid nitrogen refrigeration, which adopts the following technical solutions: A superconducting hydrogen electric propulsion system with liquid hydrogen cold storage and liquid nitrogen refrigeration includes an engine and an electric propulsion mechanism, the electric propulsion mechanism including 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, and the superconducting motor drives a load to operate. The cooling channel provides a superconducting operating environment for the electric propulsion mechanism. The system also includes 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. The liquid hydrogen storage tank delivers hydrogen fuel to the engine through a hydrogen delivery pipeline, the heating device is used to heat the liquid hydrogen to vaporize the liquid hydrogen, and the hydrogen delivery pipeline between the liquid hydrogen storage tank and the heating device is connected to a channel in the first heat exchanger; The liquid nitrogen delivery circuit includes an output pipeline and a recovery pipeline, wherein the output pipeline is connected to the outlet of the liquid nitrogen storage tank and the inlet of the cooling channel, the recovery pipeline is connected to the outlet of the cooling channel and the recovery inlet of the liquid nitrogen storage tank, and the recovery pipeline is connected to another channel in the first heat exchanger.

[0007] Optionally, the superconducting hydrogen electric propulsion system with liquid hydrogen cold storage and liquid nitrogen refrigeration also includes a refrigeration component, which is used to maintain the liquid hydrogen in the liquid hydrogen storage tank at a first preset temperature. The refrigeration component is also used to maintain the liquid nitrogen in the liquid nitrogen storage tank at a second preset temperature before the engine is shut down and the speed reaches the target operating state.

[0008] Optionally, the hydrogen delivery pipeline includes a first branch pipeline, a second branch pipeline and a main delivery pipeline, the first branch pipeline and the second branch pipeline are both connected to the inlet of the main delivery pipeline through a heating device, the main delivery pipeline delivers vaporized hydrogen to the engine, and the first branch pipeline between the heating device and the liquid hydrogen storage tank is connected to the first heat exchanger; A second heat exchanger is connected to the second branch pipeline between the heating device and the liquid hydrogen storage tank, and the second heat exchanger uses the internal heat of the engine to heat the liquid hydrogen in the second branch pipeline.

[0009] Optionally, the engine is a gas turbine engine.

[0010] Optionally, the second heat exchanger utilizes the heat of engine exhaust gas or the heat of high-pressure compressor outlet gas to heat the liquid hydrogen in the second branch pipeline.

[0011] Optionally, the superconducting hydrogen electric propulsion system with liquid hydrogen cold storage and liquid nitrogen refrigeration also includes an energy storage component, which is connected to the output electrode of the superconducting generator and is used to store the electrical energy generated by the superconducting generator.

[0012] In summary, this application has the following beneficial technical effects: In the present application, low-temperature liquid nitrogen is transported to the cooling channel through a liquid nitrogen transport pipeline to provide a low-temperature environment for high-temperature superconductivity for superconducting generators, superconducting motors and related superconducting cables. Liquid nitrogen is used as a superconducting medium to achieve high-temperature superconductivity. The liquid nitrogen after cooling is heated and returned to the liquid nitrogen storage tank through the first heat exchanger through a recovery pipeline. The heated nitrogen is cooled by the cold energy of liquid hydrogen in the first heat exchanger, and the cooled liquid nitrogen returns to the liquid nitrogen storage tank. The cooled liquid nitrogen re-enters the liquid nitrogen storage tank and is provided to the cooling channel. At the same time, the liquid hydrogen is heated in the first heat exchanger, which can reduce the energy consumption required by the heating device to heat the vaporized hydrogen. In the whole process, liquid hydrogen is used as a fuel to absorb heat during vaporization and exchange heat with liquid nitrogen, thereby continuously ensuring the superconductivity of the electric propulsion mechanism through liquid nitrogen. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0014] Figure 1 This is a principle block diagram of the superconducting hydrogen electric propulsion system with liquid hydrogen cold storage and liquid nitrogen refrigeration in an embodiment of the present application.

[0015] Explanation of the accompanying drawings: 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. Main 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

[0016] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0017] The following describes the embodiments of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, in the absence of conflict, the features in the following embodiments and embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of this application.

[0018] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on this application, it should be understood by those skilled in the art that an aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects described herein can be used to implement an apparatus and / or practice a method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this apparatus and / or practice this method.

[0019] It should also be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present application. The illustrations only show components related to the present application and are not drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component can be changed at will, and the component layout type may also be more complicated.

[0020] Additionally, in the following description, specific details are provided to provide a thorough understanding of the examples. However, one skilled in the art will appreciate that the aspects described can be practiced without these specific details.

[0021] The embodiments of the present application provide a superconducting hydrogen electric propulsion system with liquid hydrogen cold storage and liquid nitrogen refrigeration.

[0022] like Figure 1 As shown, a superconducting hydrogen electric propulsion system with liquid hydrogen cold storage and liquid nitrogen refrigeration 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 electric propulsion mechanism with the temperature environment required for superconducting operation. 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 cables. Among them, the superconducting generator 2 and the superconducting motor 3 are prior art, and the two are not the innovation points of this application, so the specific structures of the two are not repeated here. The engine is an engine that uses hydrogen as fuel.

[0023] The superconducting hydrogen electric propulsion system with liquid hydrogen cold storage and liquid nitrogen refrigeration of the present application also includes 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.

[0024] The liquid hydrogen storage tank 5 supplies hydrogen fuel to the engine 1 via a hydrogen delivery pipeline. The heating device 9 is used to heat the liquid hydrogen to vaporize it. The vaporized hydrogen is then supplied to the engine 1. 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 heating device 9 provides heat to ensure the vaporization of the liquid hydrogen.

[0025] The liquid nitrogen delivery circuit includes an output pipeline 61 and a recovery pipeline 62. The output pipeline 61 connects the outlet of the liquid nitrogen storage tank 6 and the inlet of the cooling channel 4. The recovery pipeline 62 connects the outlet of the cooling channel 4 and the recovery inlet of the liquid nitrogen storage tank 6. The recovery pipeline 62 connects another channel in the first heat exchanger 7.

[0026] In the present application, low-temperature liquid nitrogen is transported to the cooling channel 4 through a transport pipeline to provide a low-temperature environment for high-temperature superconductivity for the superconducting generator 2, the superconducting motor 3 and the related superconducting cables. Liquid nitrogen is used as a superconducting medium to achieve high-temperature superconductivity. The liquid nitrogen after cooling is heated and returned to the liquid nitrogen storage tank through the recovery pipeline 62 through the first heat exchanger 7. In the first heat exchanger 7, the heated nitrogen is cooled by the cold energy of liquid hydrogen, and the cooled liquid nitrogen is returned to the liquid nitrogen storage tank 6. The cooled liquid nitrogen re-enters the liquid nitrogen storage tank 6 and is provided to 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 by the heating device 9 to heat the vaporized hydrogen. In the whole process, liquid hydrogen is used as a fuel to absorb heat during vaporization and exchange heat with liquid nitrogen, thereby continuously ensuring the superconductivity of the electric propulsion mechanism through liquid nitrogen.

[0027] Compared with the hydrogen-electric propulsion system of pure liquid hydrogen superconductor, this application has lower refrigeration cost and material cost, smaller additional mass of the refrigeration system, and avoids the possibility of eddy current or leakage current reacting with liquid hydrogen to cause deflagration and explosion, which significantly improves the safety factor of the superconducting hydrogen-electric propulsion system; compared with the traditional liquid nitrogen superconductor method, hydrogen-electric propulsion technology significantly reduces carbon emissions and can theoretically achieve zero emissions; and compared with traditional electric propulsion technology, this application improves the output power of the low-temperature cooling loop, and the carrying efficiency will be greatly improved, which has significant advantages in energy conservation, emission reduction, cost reduction and efficiency improvement. It can be used for experimental research and engineering application of hydrogen-electric propulsion systems. The hydrogen-electric propulsion technology of liquid hydrogen cold storage and liquid nitrogen superconductor can achieve zero pollution and zero emissions, safe superconductivity, high output power, lightweight refrigeration system, reduced refrigeration cost and reduced material cost, which meets the application requirements of future power for energy conservation, emission reduction, cost reduction and efficiency improvement.

[0028] 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 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.

[0029] The superconducting hydrogen electric propulsion system with liquid hydrogen cold storage and liquid nitrogen refrigeration also includes a refrigeration component 12, which is used to maintain the liquid hydrogen in the liquid hydrogen storage tank 5 at a first preset temperature. The refrigeration 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 is shut down and the speed reaches the target operating state.

[0030] 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; 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. The second heat exchanger 8 uses the internal heat of the engine 1 to heat the liquid hydrogen in the second branch pipeline 52.

[0031] In the embodiment of the present application, the operation of each component of the system under different states of the engine 1 is as follows.

[0032] The engine 1 is in a parking standby state: the refrigeration component 12 provides refrigeration 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 to the outside, and the liquid nitrogen state in the liquid nitrogen storage tank 6 is maintained by the refrigeration component 12. When the engine is parked and on standby, the heating device 9 is in a standby state, and the superconducting generator 2 and the superconducting motor 3 are also in a standby state. The heat is less, and excessive refrigeration is not required to maintain the system from losing superconductivity. The liquid nitrogen storage tank 6 supplies a lower liquid nitrogen flow rate to the cooling channel 4 to achieve superconductivity of the electric propulsion mechanism.

[0033] The process of engine 1 transitioning from standby to start: From the standby state, the auxiliary starter drives engine 1 to a self-sustaining speed, and heating device 9 activates to a temperature sufficient to vaporize liquid hydrogen. Once the electric propulsion mechanism receives the engine start command, liquid hydrogen is supplied from the liquid hydrogen storage tank 5 via a second branch line 52 to the second heat exchanger 8 for liquid hydrogen and gas, and via a first branch line 51 to the first heat exchanger 7 for liquid nitrogen and liquid hydrogen. Liquid hydrogen flowing through the first and second heat exchangers 7, 8, converges at heating device 9, where it absorbs heat and vaporizes. The liquid hydrogen is then injected through a pipeline into the combustion chamber of engine 1 for combustion. Engine 1 outputs mechanical energy to superconducting generator 2, generating electrical energy. Some of this energy is stored in electrical energy storage assembly 10, and some is supplied to superconducting motor 3 to drive a load, generating power for the hydrogen-electric propulsion system. This load can be a propeller 11.

[0034] Since liquid hydrogen is present on the liquid nitrogen recovery line 62 to cool the liquid nitrogen, the refrigeration capacity 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 where the liquid nitrogen working medium flows.

[0035] The process of the engine reaching the set target operating state: According to the set target operating state of the engine, the liquid hydrogen flow provided by the liquid hydrogen storage tank 5 is continuously increased to match the current speed of the engine 1. In this process, the AC and DC losses of the electric propulsion mechanism increase, and the liquid nitrogen flow supplied from the liquid nitrogen storage tank to the cooling channel 4 will also increase to maintain the electric propulsion mechanism from losing supersonic speed.

[0036] As the speed of the engine 1 increases, the temperature of the gas at the engine outlet continues to increase, and the heat of the high-temperature gas is used to heat the liquid hydrogen in the second heat exchanger 8. This operation also improves the overall stealth performance of the hydrogen-electric propulsion system and reduces the energy consumption of the heating device 9. This reduces the energy consumed by auxiliary heating and saves the cost of liquid hydrogen vaporization.

[0037] At this time, due to the increase in the supply of liquid hydrogen, the liquid nitrogen in the first heat exchanger 7 has a sufficient cooling effect on the liquid nitrogen, and the liquid nitrogen is maintained at a low temperature. The refrigeration component 12 does not need to provide refrigeration capacity to the liquid nitrogen storage tank 6.

[0038] Engine deceleration from braking to parking state: In response to the engine's braking command, the liquid hydrogen storage tank 5 ceases supplying hydrogen. The remaining mechanical energy from the engine 1 is converted into electrical energy for storage via the superconducting generator 2. This process halts the supply of liquid nitrogen to the cooling channel 4, eliminating the need to maintain superconductivity in the electric propulsion mechanism. The vaporized liquid nitrogen is then discharged through the overflow device. When the hydrogen-electric propulsion system is fully shut down, the overflow device for vaporizing liquid nitrogen closes, and the system enters standby mode for the next shutdown.

[0039] In one embodiment, the second heat exchanger 8 uses the heat of the engine exhaust or the heat of the high-pressure compressor outlet gas to heat the liquid hydrogen in the second branch pipeline 52. Specifically, an air bleed pipe is set at the outlet of the high-pressure compressor, one of the channels inside the second heat exchanger 8 is a bleed pipe, and another pipe in the second heat exchanger 8 is connected to the second branch pipeline 52, and 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.

[0040] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A superconducting hydrogen electric propulsion system with liquid hydrogen cold storage and liquid nitrogen refrigeration, 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 a 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 circuit, a first heat exchanger (7), and a heating device (9); The liquid hydrogen storage tank (5) delivers hydrogen fuel to the engine (1) via a hydrogen delivery pipeline, the heating device (9) is used to heat the liquid hydrogen to vaporize the liquid hydrogen, and 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 comprises an output pipeline (61) and a recovery pipeline (62), wherein the output pipeline (61) is connected to the outlet of the liquid nitrogen storage tank (6) and the inlet of the cooling channel (4), and 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), and the recovery pipeline (62) is connected to another channel in the first heat exchanger (7).

2. The superconducting hydrogen electric propulsion system with liquid hydrogen cold storage and liquid nitrogen refrigeration according to claim 1 is characterized in that: The superconducting hydrogen electric propulsion system with liquid hydrogen cold storage and liquid nitrogen refrigeration further includes a refrigeration component (12), which is used to maintain the liquid hydrogen in the liquid hydrogen storage tank (5) at a first preset temperature, and the refrigeration 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) is shut down and the speed reaches a target operating state.

3. The superconducting hydrogen electric propulsion system with liquid hydrogen cold storage and liquid nitrogen refrigeration according to claim 1 is characterized in that: The hydrogen delivery pipeline comprises 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 a heating device (9); the main delivery pipeline (53) delivers 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 pipeline (52) between the heating device (9) and the liquid hydrogen storage tank (5), and the second heat exchanger (8) uses the internal heat of the engine (1) to heat the liquid hydrogen in the second branch pipeline (52).

4. The superconducting hydrogen electric propulsion system with liquid hydrogen cold storage and liquid nitrogen refrigeration according to claim 3 is characterized in that: The engine (1) is a gas turbine engine.

5. The superconducting hydrogen electric propulsion system with liquid hydrogen cold storage and liquid nitrogen refrigeration according to claim 4 is characterized in that: The second heat exchanger (8) utilizes the heat of the exhaust gas of the engine (1) or the heat of the high-pressure compressor outlet gas to heat the liquid hydrogen in the second branch pipeline (52).

6. The superconducting hydrogen electric propulsion system with liquid hydrogen cold storage and liquid nitrogen refrigeration according to claim 1 is characterized in that: The superconducting hydrogen electric propulsion system with liquid hydrogen cold storage and liquid nitrogen refrigeration further comprises an energy storage component (10), wherein the energy storage component (10) is connected to the output electrode of the superconducting generator (2) and is used for storing the electric energy generated by the superconducting generator (2).

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