An integrated management system and method for liquid hydrogen aircraft

Abstract

The present invention discloses an integrated management system for liquid hydrogen aircraft and a method thereof. The system uses the coupling effect of a temperature three-way valve and a flow three-way valve to precisely control the temperature and flow of liquid hydrogen before it enters supercriticality, effectively solving the control problem caused by the transformation of the physical properties of supercritical hydrogen; at the same time, the excess high-pressure liquid hydrogen in the flow regulation process is directly throttled to cool the liquid hydrogen storage tank, achieving the effective unification of liquid hydrogen flow regulation and lossless storage, and reducing the liquid hydrogen loss rate. In addition, the present invention uses a para-orthohydrogen conversion precooler and a liquid hydrogen vaporizer to fully precool the air before it enters the compressor, which can effectively improve the compression efficiency of the compressor and fully utilize the cooling capacity of the liquid hydrogen medium; and the water generated by the fuel cell reaction is used to pre-cool the high-temperature coolant from the engine, thereby improving the overall energy utilization rate of the liquid hydrogen aircraft.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid hydrogen aircraft, and in particular to an integrated management system and method for liquid hydrogen aircraft. Background Art

[0002] The continued development of the global economy has driven steady growth in the aviation industry, but this has also brought with it increasing energy consumption and environmental pollution, leading to increasingly prominent problems. Hydrogen is the most likely fuel for future new energy regional aircraft. This is because hydrogen has a higher calorific value per unit mass than kerosene, a higher specific energy density, and primarily produces water through combustion or electrochemical processes, resulting in net-zero emissions. This makes it one of the most promising new energy sources for aviation worldwide.

[0003] Current commercial aircraft plans favor liquid hydrogen as a fuel. Liquid hydrogen has a volume ten times that of jet fuel of the same mass. Furthermore, its transportation, safety, thermal management, and refueling differ from those of traditional jet fuel. In particular, liquid hydrogen often enters a supercritical state during use, and the sudden change in physical properties during this transcritical process significantly increases the difficulty of regulating flow and temperature. Therefore, an efficient and controllable hydrogen energy storage and supply system has become a key technology that must be addressed in the development of liquid hydrogen aircraft. Summary of the Invention

[0004] The purpose of the present invention is to provide an integrated management system for liquid hydrogen aircraft. By setting up a dual-loop control structure, the temperature and flow rate of liquid hydrogen entering the engine can be precisely controlled. The air entering the liquid hydrogen aircraft is fully pre-cooled by utilizing the cooling capacity of liquid hydrogen vaporization and the cooling capacity of para-orthohydrogen conversion, thereby increasing the air intake and improving the operating efficiency of the compressor.

[0005] The present invention intends to achieve the purpose of the present invention by the following technical solutions:

[0006] In a first aspect, the present invention provides an integrated management system for a liquid hydrogen aircraft, which includes a hydrogen pipeline, a temperature control branch, a flow control pipeline, an air pipeline, a fuel cell air pipeline, a coolant circulation pipeline, and a water pipeline;

[0007] The orthohydrogen conversion precooler, the liquid hydrogen vaporizer, and the coolant heat exchanger each have a first channel and a second channel for heat exchange;

[0008] The hydrogen pipeline is sequentially connected to the liquid hydrogen storage tank, the liquid hydrogen shut-off valve, the liquid hydrogen booster pump, the inlet of the temperature three-way valve, the first outlet of the temperature three-way valve, the inlet of the flow three-way valve, the first outlet of the flow three-way valve, the pressure sensor, the temperature sensor, the flow meter, the second channel of the liquid hydrogen vaporizer, the second channel of the para-orthohydrogen conversion precooler and the hydrogen inlet of the engine, and is used to pressurize and vaporize the liquid hydrogen medium in the liquid hydrogen storage tank and then transport it to the engine for combustion;

[0009] The temperature control branch is connected in sequence to the second outlet of the temperature three-way valve, the para-orthohydrogen conversion thermostat, and then connected to the hydrogen pipeline between the temperature three-way valve and the flow three-way valve; the para-orthohydrogen conversion thermostat is used to provide the input liquid hydrogen for the endothermic para-orthohydrogen conversion reaction, and the liquid hydrogen is cooled by the reaction, thereby adjusting the liquid hydrogen temperature of the input flow three-way valve in the hydrogen pipeline;

[0010] The flow control pipeline is connected in sequence to the second outlet of the flow three-way valve, the throttle, the cooler in the liquid hydrogen storage tank, and the hydrogen inlet of the fuel cell. It is used to throttle the excess high-pressure liquid hydrogen in the hydrogen pipeline, generate cold energy, and then cool the liquid hydrogen medium in the liquid hydrogen storage tank to achieve lossless storage. The liquid hydrogen is then vaporized by heat exchange and enters the fuel cell for reaction.

[0011] The air pipeline is sequentially connected to the intake fan, the first channel of the orthohydrogen conversion precooler, the first channel of the liquid hydrogen vaporizer, the engine air shut-off valve, the compressor, and the air inlet of the engine, and is used to cool the air heated after being compressed by the intake fan;

[0012] The front end of the fuel cell air pipeline is connected to the air pipeline between the liquid hydrogen vaporizer and the engine air shut-off valve, and then sequentially connected to the fuel cell air shut-off valve, the first channel of the coolant heat exchanger, and the air inlet of the fuel cell, so as to cool down the coolant with part of the air in the air pipeline before inputting it into the fuel cell for reaction;

[0013] The coolant circulation pipeline is connected in sequence to the coolant outlet of the engine, the coolant circulation pump, the dry channel of the dew point indirect evaporative cooler, the second channel of the coolant heat exchanger, and then reconnected to the coolant inlet of the engine to achieve heat dissipation and cooling of the engine;

[0014] The water pipeline is connected in sequence to the product water outlet of the fuel cell, the water valve, and the wet channel of the dew point indirect evaporative cooler, and is used to transport the water generated by the fuel cell to the dew point indirect evaporative cooler to generate the cooling capacity required by the coolant through evaporative cooling, and the generated water vapor is directly discharged.

[0015] As a preferred embodiment of the first aspect, a controller is further included. The controller is connected to the pressure sensor, the temperature sensor, and the flow meter through signal lines, and is also connected to the temperature three-way valve and the flow three-way valve through signal lines. The controller adjusts the opening of the temperature three-way valve and the flow three-way valve according to the collected pressure, temperature, and flow signal feedback control, so as to achieve precise control of the target flow and target temperature before the liquid hydrogen enters the supercritical state.

[0016] As a preferred embodiment of the first aspect, the liquid hydrogen storage tank supplies liquid hydrogen by self-pressurization or pumping.

[0017] As a preferred embodiment of the first aspect, the hydrogen pipeline, liquid hydrogen storage tank, liquid hydrogen booster pump, para-orthohydrogen conversion thermostat, flow control pipeline, throttle, para-orthohydrogen conversion precooler, liquid hydrogen vaporizer, coolant heat exchanger, coolant circulation pump, and dew point indirect evaporative cooler are all provided with insulating materials.

[0018] As a preferred embodiment of the first aspect, the liquid hydrogen flow channel of the para-ortho-hydrogen conversion thermostat is filled with a catalyst for the para-ortho-hydrogen conversion reaction, which can catalyze the conversion reaction of liquid hydrogen to generate cold energy for temperature regulation.

[0019] As a preferred embodiment of the first aspect, the second channel of the para-ortho-hydrogen conversion precooler is filled with a para-ortho-hydrogen conversion catalyst, which can catalyze the conversion reaction of liquid hydrogen to generate cold for precooling.

[0020] As a preferred embodiment of the first aspect above, the cooler is a heat exchange coil.

[0021] As a preferred embodiment of the first aspect above, the coolant in the coolant circulation pipeline is R134a refrigerant.

[0022] As a preferred embodiment of the first aspect, a heat exchange coil is provided outside the engine, and the coolant in the coolant circulation pipeline cools the engine by flowing through the heat exchange coil.

[0023] In a second aspect, the present invention provides a comprehensive control method for a liquid hydrogen aircraft using any system of any solution of the first aspect, comprising:

[0024] S1. Obtain two preset target parameters: liquid hydrogen temperature T and flow rate m before entering the liquid hydrogen vaporizer; first, open the liquid hydrogen shut-off valve and start the liquid hydrogen booster pump. The liquid hydrogen medium in the liquid hydrogen storage tank first passes through the liquid hydrogen shut-off valve and enters the liquid hydrogen booster pump for pressurization, and then enters the temperature three-way valve and the flow three-way valve for diversion;

[0025] S2. After passing through the temperature three-way valve, the liquid hydrogen is divided into two paths. One path continues to advance along the hydrogen pipeline, and the other path enters the temperature control branch. After the temperature is reduced by the para-ortho-hydrogen conversion reaction under the action of the catalyst in the para-ortho-hydrogen conversion thermostat, it flows into the hydrogen pipeline again. The controller adjusts the opening of the temperature three-way valve according to the signal of the temperature sensor, so that the temperature of the mixed liquid hydrogen reaches the set liquid hydrogen temperature T value. The controller controls the liquid hydrogen temperature in the following way: when the temperature sensed by the temperature sensor exceeds the T value, the flow rate delivered to the temperature control branch is increased by adjusting the opening of the temperature three-way valve. When the temperature sensed by the temperature sensor is lower than the T value, the flow rate delivered to the temperature control branch is reduced by adjusting the opening of the temperature three-way valve. Through continuous feedback control, the temperature sensed by the temperature sensor is finally maintained at the set T value.

[0026] S3. After the liquid hydrogen continues to pass through the flow three-way valve, it is divided into two paths. One path continues to advance along the hydrogen pipeline, and the other path enters the flow control pipeline. The controller adjusts the opening of the flow three-way valve according to the signal of the flow meter, so that the liquid hydrogen flow after passing through the flow three-way valve reaches the set flow m value. The controller controls the liquid hydrogen flow rate as follows: when the flow rate in the hydrogen pipeline measured by the flow meter exceeds the m value, the excess liquid hydrogen is transported to the flow control pipeline by adjusting the opening of the flow three-way valve. When the flow rate in the hydrogen pipeline measured by the flow meter is less than the m value, the power of the liquid hydrogen booster pump is increased. Through continuous feedback, the liquid hydrogen flow measured by the flow meter is finally maintained at the set m value.

[0027] S4, liquid hydrogen at a set temperature T and flow rate m is fed into the second channel of the liquid hydrogen vaporizer, where it is converted from liquid to supercritical after releasing cold energy, and then continues to enter the secondary ortho-hydrogen conversion precooler, where it further releases cold energy through secondary ortho-hydrogen conversion under the action of a catalyst, and finally enters the engine;

[0028] During S5, the high-pressure liquid hydrogen entering the flow control pipeline first enters the throttle, where it is cooled by throttling, and then enters the cooler built into the liquid hydrogen storage tank to cool the high-temperature liquid hydrogen in the upper part of the liquid hydrogen storage tank to prevent evaporation loss. The hydrogen generated by the vaporization of the high-pressure liquid hydrogen after releasing the cold energy continues to enter the fuel cell;

[0029] S6. Open the engine air shutoff valve, fuel cell air shutoff valve, and water valve, start the intake fan and compressor, and allow external air to enter the air pipeline. After passing through the intake fan, the air is heated and pressurized, then enters the first channel of the secondary orthohydrogen conversion precooler to absorb the secondary orthohydrogen conversion cold energy for preliminary cooling, and then enters the first channel of the liquid hydrogen vaporizer to absorb the liquid hydrogen cold energy for deep cooling to form low-temperature air. After deep cooling, the low-temperature air is divided into two paths. One path continues to pass through the engine air shutoff valve to enter the compressor for compression, and then enters the engine to burn with hydrogen to generate thrust. The other path passes through the fuel cell air shutoff valve to enter the fuel cell air pipeline. In the fuel cell air pipeline, the low-temperature air first enters the first channel of the coolant heat exchanger to release cold energy, and then enters the fuel cell to react with hydrogen to generate electricity. The water generated during the operation of the fuel cell enters the water pipeline, and enters the wet channel of the dew point indirect evaporative cooler through the water valve to evaporate and generate cold energy, and is finally discharged directly.

[0030] S7. Start the coolant circulation pump, so that the coolant in the coolant circulation pipeline first enters the dry channel of the dew point indirect evaporative cooler under the drive of the coolant circulation pump for preliminary cooling, then enters the second channel of the coolant heat exchanger to absorb the cold air for further cooling, and returns to the engine for cooling after reaching the set temperature, thereby improving the operating efficiency of the engine.

[0031] Compared with the prior art, the present invention has the following outstanding and beneficial technical effects: through the coupling effect of the temperature three-way valve and the flow three-way valve, the temperature and flow of liquid hydrogen are precisely controlled before it enters the supercritical state, effectively solving the control problem caused by the transformation of the physical properties of supercritical hydrogen; during the flow regulation process, the excess high-pressure liquid hydrogen is directly throttled to cool the liquid hydrogen storage tank, thereby achieving the effective unification of liquid hydrogen flow regulation and lossless storage, and reducing the liquid hydrogen loss rate; a para-orthohydrogen conversion precooler and a liquid hydrogen vaporizer are used to fully precool the air before entering the compressor, which can effectively improve the compression efficiency of the compressor and fully utilize the cooling capacity of the liquid hydrogen medium; the water generated by the fuel cell reaction is used to pre-cool the high-temperature coolant from the engine, thereby improving the overall energy utilization rate of the liquid hydrogen aircraft.

[0032] The concept, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings to fully understand the purpose, characteristics and effects of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 The diagram is a structural diagram of an integrated management system for liquid hydrogen aircraft according to the present invention.

[0034] In the figure: hydrogen pipeline 1, liquid hydrogen storage tank 2, liquid hydrogen shut-off valve 3, liquid hydrogen booster pump 4, temperature three-way valve 5, flow three-way valve 6, pressure sensor 7, temperature sensor 8, flow meter 9, temperature control branch 10, orthohydrogen conversion thermostat 11, flow control pipeline 12, throttle 13, lossless storage cooler 14, fuel cell 15, signal line 16, controller 17, air pipeline 18, intake fan 19, orthohydrogen conversion precooler 20, liquid hydrogen vaporizer 21, engine air shut-off valve 22, compressor 23, engine 24, fuel cell air pipeline 25, fuel cell air shut-off valve 26, coolant heat exchanger 27, coolant circulation pipeline 28, coolant circulation pump 29, dew point indirect evaporative cooler 30, water pipeline 31, water valve 32. DETAILED DESCRIPTION

[0035] In order to make the above-mentioned objects, features and advantages of the present invention more clearly understood, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below. The technical features in the various embodiments of the present invention can be combined accordingly without conflicting with each other.

[0036] In the description of the present invention, it should be understood that when an element is considered to be "connected" to another element, it can be directly connected to the other element or indirectly connected, that is, there are intermediate elements. On the contrary, when an element is said to be "directly" connected to another element, there are no intermediate elements.

[0037] In the description of the present invention, it should be understood that the terms "first" and "second" are used solely for descriptive purposes and are not to be construed as indicating or implying relative importance or implicitly specifying the number of technical features being described. Therefore, features defined as "first" or "second" may explicitly or implicitly include at least one of such features.

[0038] In addition, in the description of the present invention, it should be understood that expressions such as "high temperature", "low temperature", "high pressure" and "low pressure" are only used to distinguish relative high and low, and cannot be understood as limiting the absolute values ​​of temperature and pressure.

[0039] See also Figure 1 In a preferred embodiment of the present invention, an integrated management system for a liquid hydrogen aircraft is provided, comprising a hydrogen pipeline 1, a liquid hydrogen storage tank 2, a liquid hydrogen shutoff valve 3, a liquid hydrogen booster pump 4, a temperature three-way valve 5, a flow three-way valve 6, a pressure sensor 7, a temperature sensor 8, a flow meter 9, a temperature control branch 10, a para-orthohydrogen conversion thermostat 11, a flow control pipeline 12, a throttle 13, a cooler 14, a fuel cell 15, a signal line 16, a controller 17, an air pipeline 18, an intake fan 19, a para-orthohydrogen conversion precooler 20, a liquid hydrogen vaporizer 21, an engine air shutoff valve 22, a compressor 23, an engine 24, a fuel cell air pipeline 25, a fuel cell air shutoff valve 26, a coolant heat exchanger 27, a coolant circulation pipeline 28, a coolant circulation pump 29, a dew point indirect evaporative cooler 30, a water pipeline 31, and a water valve 32. The assembly relationship between these components is described in detail below.

[0040] It should be noted that the temperature three-way valve 5 and the flow three-way valve 6 in the present invention are both three-way valves with one inlet and two outlets. For ease of description, the three ports of the three-way valve are referred to as the inlet, the first outlet, and the second outlet, and the flow ratio of the two outlets can be adjusted by the valve opening. The para-orthohydrogen conversion precooler 20 and the para-orthohydrogen conversion thermostat 11 in the present invention refer to precoolers and thermostats that use the para-orthohydrogen conversion endothermic reaction to provide cooling. Their specific structural forms can be similar to ordinary precoolers and thermostats, except that the cooling is provided by arranging a para-orthohydrogen conversion catalyst internally to catalyze the para-orthohydrogen conversion. The dew point indirect evaporative cooler 30 in the present invention is divided into two parts: a dry channel and a wet channel. Water evaporates in the wet channel to generate cooling, which in turn cools the medium inside the dry channel. The para-orthohydrogen conversion precooler 20 in the present invention has a first channel and a second channel that constitute heat exchange, and the working medium between the two channels can exchange cooling and heat through heat exchange. The liquid hydrogen vaporizer 21 of the present invention has a first channel and a second channel for heat exchange, allowing the working fluid between the two channels to exchange cooling and heat through heat exchange. The coolant heat exchanger 27 of the present invention has a first channel and a second channel for heat exchange, allowing the working fluid between the two channels to exchange cooling and heat through heat exchange. The specific structural forms of the para-orthohydrogen conversion precooler 20, liquid hydrogen vaporizer 21, and coolant heat exchanger 27 are not limited.

[0041] The hydrogen pipeline 1 is connected in sequence to the liquid hydrogen storage tank 2, the liquid hydrogen stop valve 3, the liquid hydrogen booster pump 4, the inlet of the temperature three-way valve 5, the first outlet of the temperature three-way valve 5, the inlet of the flow three-way valve 6, the first outlet of the flow three-way valve 6, the pressure sensor 7, the temperature sensor 8, the flow meter 9, the second channel of the liquid hydrogen vaporizer 21, the second channel of the para-orthohydrogen conversion precooler 20 and the hydrogen inlet of the engine 24, and is used to pressurize the liquid hydrogen medium in the liquid hydrogen storage tank 2 (pressurized to about 16 MPa, which can be feedback controlled by the pressure sensor 7) and vaporize it and then transport it to the engine 24 for combustion.

[0042] In an embodiment of the present invention, the liquid hydrogen storage tank 2 can supply liquid hydrogen by self-pressurization or pumping.

[0043] The temperature control branch 10 mainly realizes the liquid hydrogen temperature regulation function. The temperature control branch 10 is connected to the second outlet of the temperature three-way valve 5 and the para-ortho-hydrogen conversion thermostat 11 in sequence, and then connected to the hydrogen pipeline 1 between the temperature three-way valve 5 and the flow three-way valve 6. After the liquid hydrogen booster pump 4 pressurizes the liquid hydrogen medium, the liquid hydrogen temperature will produce a certain temperature rise. After the liquid hydrogen in the temperature control branch 10 passes through the para-ortho-hydrogen conversion thermostat 11, the para-ortho-hydrogen conversion thermostat 11 can provide the input liquid hydrogen for the endothermic para-ortho-hydrogen conversion reaction, reducing the temperature of the liquid hydrogen through the reaction. The cooled liquid hydrogen is mixed with another liquid hydrogen flow path at the original temperature, thereby adjusting the liquid hydrogen temperature of the input flow three-way valve 6 in the hydrogen pipeline 1.

[0044] Flow control line 12 primarily regulates the flow of liquid hydrogen. It sequentially connects the second outlet of three-way flow valve 6, throttle 13, cooler 14 in liquid hydrogen storage tank 2, and the hydrogen inlet of fuel cell 15. It throttles excess high-pressure liquid hydrogen in hydrogen line 1, generating cold energy to cool the liquid hydrogen medium in liquid hydrogen storage tank 2 for lossless storage. After heat exchange, the liquid hydrogen vaporizes and enters fuel cell 15 for reaction. The current generated by the fuel cell can be used to support the operation of the moving components of the liquid hydrogen aircraft.

[0045] In an embodiment of the present invention, the cooler 14 in the liquid hydrogen storage tank 2 can use a heat exchange coil air pipeline 18 to connect in sequence the intake fan 19, the first channel of the orthohydrogen conversion precooler 20, the first channel of the liquid hydrogen vaporizer 21, the engine air shut-off valve 22, the compressor 23, and the air inlet of the engine 24, so as to fully cool the high-temperature air that is heated after being compressed by the intake fan 19, thereby improving the compression efficiency of the compressor 23 and reducing the thermal protection requirements.

[0046] The front end of the fuel cell air pipeline 25 is connected to the air pipeline 18 between the liquid hydrogen vaporizer 21 and the engine air shut-off valve 22, and then connected in sequence to the fuel cell air shut-off valve 26, the first channel of the coolant heat exchanger 27, and the air inlet of the fuel cell 15, so as to cool the coolant in the coolant circulation pipeline 28 with part of the low-temperature air in the air pipeline 18. The air after absorbing heat is finally input into the fuel cell 15 for reaction.

[0047] The coolant circulation pipeline 28 is connected in sequence to the coolant outlet of the engine 24, the coolant circulation pump 29, the dry channel of the dew point indirect evaporative cooler 30, the second channel of the coolant heat exchanger 27, and then reconnected to the coolant inlet of the engine 24 to achieve thermal management of the engine 24 and improve its operating efficiency by effectively dissipating heat and cooling the engine 24.

[0048] The water pipeline 31 is connected in sequence to the product water outlet of the fuel cell 15, the water valve 32, and the wet channel of the dew point indirect evaporative cooler 30, and is used to transport the water generated by the fuel cell 15 to the dew point indirect evaporative cooler 30, generate the cooling capacity required by the coolant through evaporative cooling, and the generated water vapor is directly discharged.

[0049] In addition, in theory, the above-mentioned management system can be manually controlled, but considering the control accuracy and precision, a controller 17 is provided in the embodiment of the present invention for automatic feedback control. The controller 17 can be implemented by an automatic control device such as a single chip microcomputer, a PLC, an MCU, a DCS, etc., without limitation. The controller 17 is connected to the pressure sensor 7, the temperature sensor 8, and the flow meter 9 via a signal line 16, and is also connected to the temperature three-way valve 5 and the flow three-way valve 6 via a signal line 16. The controller 17 adjusts the opening of the temperature three-way valve 5 and the flow three-way valve 6 according to the pressure, temperature and flow signals collected by the pressure sensor 7, the temperature sensor 8, and the flow meter 9, respectively, and then feedback controls the opening of the temperature three-way valve 5 and the flow three-way valve 6, thereby achieving precise control of the target flow and target temperature before the liquid hydrogen enters the supercritical state.

[0050] Furthermore, in the integrated management system for liquid hydrogen aircraft described above, insulating materials can be installed externally on the hydrogen pipeline 1, liquid hydrogen storage tank 2, liquid hydrogen booster pump 4, para-orthohydrogen conversion thermostat 11, flow control pipeline 12, throttle 13, para-orthohydrogen conversion precooler 20, liquid hydrogen vaporizer 21, coolant heat exchanger 27, coolant circulation pump 29, and dew-point indirect evaporative cooler 30 to prevent heat leakage. The coolant in the coolant circulation pipeline 28 is preferably R134a refrigerant. A heat exchange coil can be installed externally on the engine 24. The coolant in the coolant circulation pipeline 28 cools the engine 24 by flowing through the heat exchange coil.

[0051] Furthermore, in an embodiment of the present invention, the liquid hydrogen flow channel of the para-orthohydrogen conversion thermostat 11 is filled with a para-orthohydrogen conversion catalyst, which catalyzes the conversion of liquid hydrogen to generate cooling energy for temperature regulation. The second channel of the para-orthohydrogen conversion precooler 20 is also filled with a para-orthohydrogen conversion catalyst, which catalyzes the conversion of liquid hydrogen to generate cooling energy for precooling. The specific material type of the para-orthohydrogen conversion catalyst is not limited, provided that it exhibits high catalytic activity.

[0052] In another embodiment of the present invention, based on the above Figure 1 The integrated management system of the liquid hydrogen aircraft shown also provides an integrated control method for the liquid hydrogen aircraft, as follows:

[0053] First assume that all valves are closed and all devices and components are stopped.

[0054] (1) Two target parameters are pre-set, namely the liquid hydrogen temperature T and flow rate m before entering the liquid hydrogen vaporizer 21. Based on these two target parameters, the hydrogen flow rate of the engine 24 is precisely controlled. First, the liquid hydrogen stop valve 3 is opened, and the liquid hydrogen booster pump 4 is started. The liquid hydrogen medium in the liquid hydrogen storage tank 2 first passes through the liquid hydrogen stop valve 3 and enters the liquid hydrogen booster pump 4 for pressurization. The liquid hydrogen state changes from a low pressure state to a high pressure state, and then enters the temperature three-way valve 5 and the flow three-way valve 6 for diversion.

[0055] (2) After passing through the temperature three-way valve 5, the liquid hydrogen is divided into two paths. One path continues to move along the hydrogen pipeline 1, and the other path enters the temperature control branch 10. After the temperature is cooled by the catalyst in the para-ortho-hydrogen conversion thermostat 11, it flows into the hydrogen pipeline 1 again. The controller 17 adjusts the opening of the temperature three-way valve 5 according to the signal of the temperature sensor 8, so that the temperature of the mixed liquid hydrogen reaches the set liquid hydrogen temperature T value; the controller 17 controls the temperature of the liquid hydrogen in the following way: when the temperature sensed by the temperature sensor 8 exceeds the T value, the flow rate delivered to the temperature control branch 10 is increased by adjusting the opening of the temperature three-way valve 5; when the temperature sensed by the temperature sensor 8 is lower than the T value, the flow rate delivered to the temperature control branch 10 is reduced by adjusting the opening of the temperature three-way valve 5. Through continuous feedback control, the temperature sensed by the temperature sensor 8 is finally kept at the set T value.

[0056] (3) After the liquid hydrogen continues to pass through the flow three-way valve 6, it is divided into two paths. One path continues to move along the hydrogen pipeline 1, and the other path enters the flow control pipeline 12. The controller 17 adjusts the opening of the flow three-way valve 6 according to the signal of the flow meter 9, so that the liquid hydrogen flow after passing through the flow three-way valve 6 reaches the set flow m value; the controller 17 controls the liquid hydrogen flow rate in the following manner: when the flow in the hydrogen pipeline 1 measured by the flow meter 9 exceeds the m value, the excess liquid hydrogen is transported to the flow control pipeline 12 by adjusting the opening of the flow three-way valve 6; when the flow in the hydrogen pipeline 1 measured by the flow meter 9 is less than the m value, the power of the liquid hydrogen booster pump 4 is increased, and the liquid hydrogen flow measured by the flow meter 9 is finally maintained at the set m value through continuous feedback.

[0057] (4) Liquid hydrogen at a set temperature T and flow rate m is input into the second channel of the liquid hydrogen vaporizer 21, and after releasing the cold, it changes from liquid to supercritical state, and then continues to enter the secondary ortho-hydrogen conversion precooler 20, and further releases the cold through the secondary ortho-hydrogen conversion under the action of the catalyst, and finally enters the engine 24.

[0058] (5) During the flow regulation process, the high-pressure liquid hydrogen entering the flow control pipeline 12 first enters the throttle 13, is cooled by throttling, and then enters the non-destructive storage cooler 14 built into the liquid hydrogen storage tank 2 to cool the high-temperature liquid hydrogen in the upper part of the liquid hydrogen storage tank 2 to prevent evaporation loss. The hydrogen generated by the vaporization of the high-pressure liquid hydrogen after releasing the cold energy continues to enter the fuel cell 15.

[0059] (6) Open the engine air shutoff valve 22, the fuel cell air shutoff valve 26, and the water valve 32, start the intake fan 19 and the compressor 23, and the external air enters the air pipe 18. After passing through the intake fan 19, the temperature and pressure are rapidly increased to a high temperature and high pressure state, and then enters the first channel of the secondary orthohydrogen conversion precooler 20, absorbs the secondary orthohydrogen conversion cold energy for preliminary cooling, and then enters the first channel of the liquid hydrogen vaporizer, absorbs the liquid hydrogen cold energy for deep cooling, and forms low-temperature air; after deep cooling, the low-temperature air is divided into two paths, one of which continues to pass through the engine air shutoff valve 22 One path enters the compressor 23 for compression, and then enters the engine 24 to burn with hydrogen to generate thrust. The other path enters the fuel cell air pipeline 25 through the fuel cell air shut-off valve 26. As for the low-temperature air entering the fuel cell air pipeline 25, it first enters the first path of the coolant heat exchanger 27 to release cold energy, and then enters the fuel cell 15 to react with hydrogen to generate electricity. In addition, the water generated when the fuel cell 15 is running enters the water pipeline 31, and enters the wet channel of the dew point indirect evaporative cooler 30 through the water valve 32 to evaporate and generate cold energy, and is finally discharged directly.

[0060] (7) The coolant circulation pump 29 is started, and the coolant in the coolant circulation pipe 28 is driven by the coolant circulation pump 29 to first enter the dry channel of the dew point indirect evaporative cooler 30 for preliminary cooling, and then enter the second channel of the coolant heat exchanger 27 to absorb the cold air for further cooling. After reaching the set temperature, the coolant returns to the engine 24 for cooling the engine 24, thereby improving the operating efficiency of the engine 24.

[0061] It should also be noted that the numbers (1) to (7) in the above method flow do not specifically refer to the order of operations in actual use, but are only used to distinguish the implementation of a certain path or a certain function. In actual operation, certain or individual steps will be performed simultaneously, separately or sequentially according to the actual operating conditions.

[0062] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention 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 invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. An integrated management system for liquid hydrogen aircraft, characterized in that: It includes a hydrogen pipeline (1), a temperature control branch (10), a flow control pipeline (12), an air pipeline (18), a fuel cell air pipeline (25), a coolant circulation pipeline (28) and a water pipeline (31); The orthohydrogen conversion precooler (20), the liquid hydrogen vaporizer (21), and the coolant heat exchanger (27) each have a first channel and a second channel for heat exchange; The hydrogen pipeline (1) is sequentially connected to the liquid hydrogen storage tank (2), the liquid hydrogen stop valve (3), the liquid hydrogen booster pump (4), the inlet of the temperature three-way valve (5), the first outlet of the temperature three-way valve (5), the inlet of the flow three-way valve (6), the first outlet of the flow three-way valve (6), the pressure sensor (7), the temperature sensor (8), the flow meter (9), the second channel of the liquid hydrogen vaporizer (21), the second channel of the para-orthohydrogen conversion precooler (20) and the hydrogen inlet of the engine (24), and is used for pressurizing and vaporizing the liquid hydrogen medium in the liquid hydrogen storage tank (2) and then transporting it to the engine (24) for combustion; The temperature control branch (10) is connected in sequence to the second outlet of the temperature three-way valve (5), the orthohydrogen conversion thermostat (11), and then connected to the hydrogen pipeline (1) between the temperature three-way valve (5) and the flow three-way valve (6); the orthohydrogen conversion thermostat (11) is used to provide the input liquid hydrogen for the endothermic orthohydrogen conversion reaction, and to reduce the temperature of the liquid hydrogen through the reaction, thereby adjusting the liquid hydrogen temperature of the input flow three-way valve (6) in the hydrogen pipeline (1); The flow control pipeline (12) is sequentially connected to the second outlet of the flow three-way valve (6), the throttle (13), the cooler (14) in the liquid hydrogen storage tank (2), and the hydrogen inlet of the fuel cell (15), and is used to throttle the excess high-pressure liquid hydrogen in the hydrogen pipeline (1), generate cold energy, and then cool the liquid hydrogen medium in the liquid hydrogen storage tank (2) to achieve lossless storage. After the liquid hydrogen is vaporized by heat exchange, it enters the fuel cell (15) for reaction; The air pipeline (18) is sequentially connected to the air intake fan (19), the first channel of the orthohydrogen conversion precooler (20), the first channel of the liquid hydrogen vaporizer (21), the engine air shutoff valve (22), the compressor (23), and the air inlet of the engine (24), and is used to cool the air heated after being compressed by the air intake fan (19); The front end of the fuel cell air pipeline (25) is connected to the air pipeline (18) between the liquid hydrogen vaporizer (21) and the engine air shut-off valve (22), and then sequentially connected to the fuel cell air shut-off valve (26), the first channel of the coolant heat exchanger (27), and the air inlet of the fuel cell (15), so as to cool down the coolant with part of the air in the air pipeline (18) and then input the coolant into the fuel cell (15) for reaction; The coolant circulation pipeline (28) is connected in sequence to the coolant outlet of the engine (24), the coolant circulation pump (29), the dry channel of the dew point indirect evaporative cooler (30), the second channel of the coolant heat exchanger (27), and then reconnected to the coolant inlet of the engine (24), thereby achieving heat dissipation and cooling of the engine (24); The water pipeline (31) is connected in sequence to the product water outlet of the fuel cell (15), the water valve (32), and the wet channel of the dew point indirect evaporative cooler (30), and is used to transport the water generated by the fuel cell (15) to the dew point indirect evaporative cooler (30) to generate the cooling capacity required by the coolant through evaporative cooling, and the generated water vapor is directly discharged.

2. The integrated management system for liquid hydrogen aircraft according to claim 1, characterized in that: The invention also includes a controller (17). The controller (17) is connected to the pressure sensor (7), the temperature sensor (8), and the flow meter (9) through a signal line (16). The controller (17) is also connected to the temperature three-way valve (5) and the flow three-way valve (6) through the signal line (16). The controller (17) adjusts the opening of the temperature three-way valve (5) and the flow three-way valve (6) according to the collected pressure, temperature and flow signal feedback control, so as to achieve accurate control of the target flow and target temperature before the liquid hydrogen enters the supercritical state.

3. The integrated management system for liquid hydrogen aircraft according to claim 1, characterized in that: The liquid hydrogen storage tank (2) supplies liquid hydrogen by self-pressurization or pumping.

4. The integrated management system for liquid hydrogen aircraft according to claim 1, characterized in that: The hydrogen pipeline (1), liquid hydrogen storage tank (2), liquid hydrogen booster pump (4), orthohydrogen conversion thermostat (11), flow control pipeline (12), throttle (13), orthohydrogen conversion precooler (20), liquid hydrogen vaporizer (21), coolant heat exchanger (27), coolant circulation pump (29), and dew point indirect evaporative cooler (30) are all provided with insulation materials on the outside.

5. The integrated management system for liquid hydrogen aircraft according to claim 1, characterized in that: The liquid hydrogen flow channel of the para-ortho-hydrogen conversion thermostat (11) is filled with a catalyst for the para-ortho-hydrogen conversion reaction, which can catalyze the conversion reaction of liquid hydrogen to generate cold energy for temperature regulation.

6. The integrated management system for liquid hydrogen aircraft according to claim 1, characterized in that: The interior of the second channel of the para-ortho-hydrogen conversion precooler (20) is filled with a catalyst for the para-ortho-hydrogen conversion reaction, which can catalyze the conversion reaction of liquid hydrogen to generate cold energy for precooling.

7. The integrated management system for liquid hydrogen aircraft according to claim 1, characterized in that: The cooler (14) is a heat exchange coil.

8. The integrated management system for liquid hydrogen aircraft according to claim 1, characterized in that: The coolant in the coolant circulation pipeline (28) is R134a refrigerant.

9. The integrated management system for liquid hydrogen aircraft according to claim 1, characterized in that: A heat exchange coil is provided outside the engine (24), and the coolant in the coolant circulation pipeline (28) cools the engine (24) by flowing through the heat exchange coil.

10. A comprehensive control method for a liquid hydrogen aircraft using the system according to any one of claims 1 to 9, characterized in that: include: S1. Obtain two preset target parameters of liquid hydrogen temperature T and flow rate m before entering the liquid hydrogen vaporizer (21); first, open the liquid hydrogen stop valve (3), start the liquid hydrogen booster pump (4), and the liquid hydrogen medium in the liquid hydrogen storage tank (2) first passes through the liquid hydrogen stop valve (3) and enters the liquid hydrogen booster pump (4) for pressurization, and then enters the temperature three-way valve (5) and the flow three-way valve (6) for diversion; S2, liquid hydrogen is divided into two paths after passing through the temperature three-way valve (5), one path continues to move along the hydrogen pipeline (1), and the other path enters the temperature control branch (10), and flows into the hydrogen pipeline (1) again after the temperature is reduced by the secondary orthohydrogen conversion reaction under the action of the catalyst in the secondary orthohydrogen conversion thermostat (11). The controller (17) adjusts the opening of the temperature three-way valve (5) according to the signal of the temperature sensor (8), thereby making the temperature of the mixed liquid hydrogen reach the set liquid hydrogen temperature T value; the controller (17) controls the temperature of the liquid hydrogen in the following logic: when the temperature sensed by the temperature sensor (8) exceeds the T value, the flow rate delivered to the temperature control branch (10) is increased by adjusting the opening of the temperature three-way valve (5); when the temperature sensed by the temperature sensor (8) is lower than the T value, the flow rate delivered to the temperature control branch (10) is reduced by adjusting the opening of the temperature three-way valve (5), and the temperature sensed by the temperature sensor (8) is finally kept at the set T value through continuous feedback control; S3, the liquid hydrogen continues to pass through the flow three-way valve (6) and is divided into two paths, one path continues to advance along the hydrogen pipeline (1), and the other path enters the flow control pipeline (12). The controller (17) adjusts the opening of the flow three-way valve (6) through the signal of the flow meter (9), thereby making the liquid hydrogen flow after passing through the flow three-way valve (6) reach the set flow m value; the controller (17) controls the liquid hydrogen flow rate in the following manner: when the flow in the hydrogen pipeline (1) measured by the flow meter (9) exceeds the m value, the excess liquid hydrogen is transported to the flow control pipeline (12) by adjusting the opening of the flow three-way valve (6); when the flow in the hydrogen pipeline (1) measured by the flow meter (9) is less than the m value, the power of the liquid hydrogen booster pump (4) is increased, and the liquid hydrogen flow measured by the flow meter (9) is finally maintained at the set m value through continuous feedback; S4, liquid hydrogen at a set temperature T and flow rate m is input into the second channel of the liquid hydrogen vaporizer (21), and after releasing cold energy, it is converted from liquid to supercritical state, and then continues to enter the secondary orthohydrogen conversion precooler (20), and further releases cold energy through secondary orthohydrogen conversion under the action of the catalyst, and finally enters the engine (24); S5. During the flow regulation process, the high-pressure liquid hydrogen entering the flow control pipeline (12) first enters the throttle (13), is cooled by throttling, and then enters the cooler (14) built into the liquid hydrogen storage tank (2), which cools the high-temperature liquid hydrogen in the upper part of the liquid hydrogen storage tank (2) to prevent evaporation loss. The hydrogen generated by the vaporization of the high-pressure liquid hydrogen after releasing the cold energy continues to enter the fuel cell (15); S6, open the engine air shutoff valve (22), the fuel cell air shutoff valve (26), and the water valve (32), start the air intake fan (19) and the compressor (23), and the outside air enters the air pipe (18), and is heated and pressurized after passing through the air intake fan (19), and then enters the first channel of the secondary orthohydrogen conversion precooler (20) to absorb the secondary orthohydrogen conversion cold energy for preliminary cooling, and then enters the first channel of the liquid hydrogen vaporizer to absorb the liquid hydrogen cold energy for deep cooling to form low-temperature air; after the deep cooling is completed, the low-temperature air is divided into two paths, one path continues to pass through the engine air shutoff valve (22) and enters the compressor (23). The air is compressed by the air compressor (23) and then enters the engine (24) to burn with hydrogen to generate thrust. The other path enters the fuel cell air pipeline (25) through the fuel cell air shut-off valve (26). In the fuel cell air pipeline (25), the low-temperature air first enters the first path of the coolant heat exchanger (27) to release cold energy, and then enters the fuel cell (15) to react with hydrogen to generate current. The water generated when the fuel cell (15) is running enters the water pipeline (31) and enters the wet channel of the dew point indirect evaporative cooler (30) through the water valve (32) to evaporate and generate cold energy, and finally is directly discharged. S7, start the coolant circulation pump (29), so that the coolant in the coolant circulation pipeline (28) first enters the dry channel of the dew point indirect evaporative cooler (30) under the drive of the coolant circulation pump (29) for preliminary cooling, then enters the second channel of the coolant heat exchanger (27) to absorb the cold air for further cooling, and returns to the engine (24) for cooling after reaching the set temperature, thereby improving the operating efficiency of the engine (24).

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