A liquid hydrogen fuel delivery system for an aircraft engine and its control method

Abstract

This invention relates to the field of aircraft propulsion system technology, and discloses an aero-engine liquid hydrogen fuel delivery system and its control method. It employs multi-branch high-precision metering to achieve wide-range, high-precision flow regulation requirements. The root method is used to determine the flow capacity of each branch, ensuring that the number of hydrogen supply branches, the available regulation ratio of the regulating valves, and the overall flow regulation ratio are matched, thus addressing the problem of high-precision fuel delivery over an extremely wide flow regulation range. A circulating coupled heat exchanger is used to rationally utilize the system's waste heat to raise the hydrogen fuel temperature to a suitable combustion level, achieving reasonable optimization of the system's heat / energy utilization, reducing fuel consumption, and improving cycle thermal efficiency. A hydrogen storage tank is used to solve the problem of mismatch between the upstream liquid hydrogen pump and heat exchanger supply flow due to the lag in the heat exchange process and the downstream regulating valve's required flow during transient fuel flow regulation.

Description

Technical Field

[0001] This invention relates to the field of aircraft propulsion system technology, and discloses an aircraft engine liquid hydrogen fuel delivery system and its control method. Background Technology

[0002] Cryogenic liquid hydrogen storage boasts high volumetric energy density and a high percentage of hydrogen stored by mass, making it the most likely hydrogen fuel storage method to meet the needs and constraints of aviation applications. However, cryogenic liquid hydrogen storage requires stringent conditions, necessitating the maintenance of the hydrogen fuel in a cryogenic, adiabatic environment at around 20K. Furthermore, hydrogen fuel is flammable and explosive, requiring improved overall energy and thermal utilization efficiency, precise flow rate regulation over a wide range, and safe operation when used in aviation gas turbines.

[0003] The following problems exist in existing turbine engine hydrogen fuel system technologies:

[0004] a. High-precision delivery over a wide flow range: Aero gas turbine engines require an extremely wide fuel throttling flow range (e.g., 3%–100%), a large control ratio (30–50), and high control accuracy across the entire range (e.g., error ≤0.2%). In engineering applications, the throttling area control accuracy of valves is indeed closely related to their position within the control range. High accuracy is typically achieved in the middle opening range (e.g., 20%–80% opening), while accuracy decreases in the small and large opening ranges. High-precision flowmeter range ratios (6–15) are smaller than the required flow throttling range, and error amplification is common at low flow rates (<10%FS). Therefore, valves and flowmeters on a single flow path can only maintain accuracy within a certain range of rated flow, making it difficult to maintain consistently high metering and control accuracy over such a wide range.

[0005] b. Traditional multi-channel regulation allocates flow according to "equal valve position" or "equal pressure loss", only considering hydraulic balance and not incorporating the change of instrument error with range position into the objective function.

[0006] c. Liquid hydrogen fuel, stored at extremely low temperatures, will consume heat from the combustion reaction due to endothermic vaporization if directly introduced into the cycle, thus affecting the cycle's thermal efficiency. Installing a dedicated vaporizer / heater will also increase energy consumption.

[0007] d. Agile response and system component matching during rapid changes in flow demand: Hydrogen fuel is stored in liquid hydrogen phase, pressurized by a liquid hydrogen pump to provide transportation power, and then precisely metered and regulated for supply to the combustion chamber after significant temperature increases through heat exchange. The phase and state parameters change dramatically throughout the transportation process. When rapid flow adjustment is required due to changes in engine operating conditions, the lag in the heat exchange process can easily lead to problems with timely flow matching between upstream and downstream units of the transportation system, such as liquid hydrogen pumps, heat exchangers, and regulating valves. Summary of the Invention

[0008] The purpose of this invention is to provide a liquid hydrogen fuel delivery system for aero-engines and its control method, which can ensure that the number of hydrogen supply branches, the available adjustment ratio of regulating valves, and the total flow rate adjustment ratio are matched, while taking into account the problem of high-precision fuel delivery over an extremely wide flow rate adjustment range.

[0009] To achieve the above-mentioned technical effects, the technical solution adopted by the present invention is as follows:

[0010] A liquid hydrogen fuel delivery system for an aircraft engine, comprising:

[0011] Liquid hydrogen storage tanks are used to store liquid hydrogen fuel;

[0012] A hydrogen temporary storage tank is connected to the liquid hydrogen storage tank via a pipeline;

[0013] A circulating coupling heat exchanger is installed on the pipeline between the liquid hydrogen storage tank and the hydrogen temporary storage tank. It is used to introduce the working fluid of the turbine engine into the circulating coupling heat exchanger, and to use the hydrogen fuel output from the liquid hydrogen storage tank to cool, reheat or cool the introduced working fluid before circulating it to the turbine engine.

[0014] The hydrogen supply assembly includes multiple parallel hydrogen supply branches, each of which is connected to the outlet of a hydrogen storage tank. These multiple hydrogen supply branches are connected to a hydrogen supply pipeline to the combustion chamber via a manifold. Each hydrogen supply branch is equipped with a regulating valve; the available regulating ratio of the regulating valve on each hydrogen supply branch is greater than a preset ratio threshold. according to Analysis yielded, among which The number of hydrogen supply branches connected to the hydrogen supply line to the combustion chamber. , This represents the maximum required total hydrogen flow rate for the combustion chamber. Minimum required total hydrogen flow rate for the combustion chamber.

[0015] Furthermore, in multiple parallel hydrogen supply branches, the design flow range of each hydrogen supply branch is as follows: ,in For the first The available adjustment ratio of the regulating valve on each hydrogen supply branch. .

[0016] Furthermore, a hydrogen-oil heat exchanger is also provided on the pipeline between the circulating coupling heat exchanger and the hydrogen storage tank, which is used to introduce turbine engine oil into the hydrogen-oil heat exchanger and use hydrogen fuel to cool the introduced oil.

[0017] Furthermore, the outlet end of the circulating coupling heat exchanger is provided with two branch lines, one of which passes through the hydrogen-lubricating oil heat exchanger to the hydrogen storage tank, and the other branch line bypasses to the hydrogen storage tank; both branch lines are equipped with regulating valves.

[0018] Furthermore, it also includes at least one venting pipe, on which a venting flame arrester is installed.

[0019] Furthermore, it also includes a nitrogen gas source for purging the pipeline between the liquid hydrogen storage tank and the hydrogen temporary storage tank, the hydrogen supply branch, and the manifold.

[0020] Furthermore, three-way valves are installed at each pipeline branch to select and set the connection status of the pipeline branch as needed, forming functional channels for hydrogen supply, purging, or venting.

[0021] To achieve the above-mentioned technical effects, the present invention also provides a control method for an aircraft engine liquid hydrogen fuel delivery system, the method being based on the aforementioned aircraft engine liquid hydrogen fuel delivery system, comprising:

[0022] When the total hydrogen supply flow rate requirement of the combustion chamber is At that time, only turn on The regulating valve of the hydrogen supply branch corresponding to the minimum value is adjusted according to the total hydrogen supply flow requirement of the combustion chamber. Hydrogen is supplied to the main combustion chamber; The coefficient is and its value range is . ;

[0023] When the total hydrogen supply flow rate requirement of the combustion chamber is At that time, only turn on The regulating valve of the hydrogen supply branch corresponding to the maximum value is based on the total hydrogen supply flow requirement of the combustion chamber. Hydrogen is supplied to the main combustion chamber;

[0024] when At that time, multiple hydrogen supply branches work in parallel. Taking the flow rate of each hydrogen supply branch as input, the optimization objective is to minimize the overall error of all hydrogen supply branches, and solve the flow distribution of each hydrogen supply branch.

[0025] Compared with the prior art, the beneficial effects of this invention are:

[0026] 1. Employ multi-branch high-precision metering to meet wide-range high-precision flow regulation requirements. Use the root method to determine the flow capacity of each branch, ensuring that the number of hydrogen supply branches, the available regulation ratio of the regulating valves, and the total flow regulation ratio requirements are matched, while also addressing the issue of high-precision fuel delivery over an extremely wide flow regulation range.

[0027] 2. By using a circulating coupled heat exchanger, the waste heat of the system is rationally utilized to raise the temperature of the hydrogen fuel to a level suitable for combustion, thereby achieving rational optimization of the system's heat / energy utilization, reducing fuel consumption, and improving the cycle thermal efficiency.

[0028] 3. The use of a hydrogen storage tank solves the problem of mismatch between the supply flow of upstream liquid hydrogen pump and heat exchanger and the required flow of downstream regulating valve during the transient process of fuel flow regulation due to the lag in the heat exchange process. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the liquid hydrogen fuel delivery system for an aero-engine in the embodiment.

[0030] Figure 2 This is a schematic diagram showing the connection principle of components and pipelines in the hydrogen fuel delivery state of the embodiment;

[0031] Figure 3 This is a schematic diagram showing the connection principle of components and pipelines in the purging heat exchange and metering stages of the embodiment;

[0032] Figure 4 This is a schematic diagram illustrating the connection principle of the components and pipelines of the combustion chamber purging nozzle in the embodiment;

[0033] The components include: 1. Liquid hydrogen storage tank; 2. Submersible liquid hydrogen pump; 3. Filter; 4. Shut-off valve; 5. Three-way valve; 6. Circulation coupling heat exchanger; 7. Regulating valve; 8. Hydrogen-lubricating oil heat exchanger; 9. Hydrogen temporary storage tank; 10. Pressure regulating valve; 11. Check valve; 12. Combustion chamber nozzle; 13. Flame arrester; 14. High-pressure nitrogen cylinder; 15. Helium storage tank; 16. Temperature sensor; 17. Pressure sensor; 18. Mass flow meter; 19. Cryogenic insulated piping; 20. Conventional piping. Detailed Implementation

[0034] The present invention will now be described in further detail with reference to the embodiments and accompanying drawings. However, this should not be construed as limiting the scope of the above-described subject matter of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0035] Example 1

[0036] See Figure 1 A liquid hydrogen fuel delivery system for an aircraft engine, comprising:

[0037] Liquid hydrogen storage tank 1, used to store liquid hydrogen fuel;

[0038] Hydrogen temporary storage tank 9 is connected to liquid hydrogen storage tank 1 via a pipeline;

[0039] The circulating coupling heat exchanger 6 is installed on the pipeline between the liquid hydrogen storage tank 1 and the hydrogen temporary storage tank 9. It is used to introduce the working fluid of the turbine engine into the circulating coupling heat exchanger 6, and use the hydrogen fuel output from the liquid hydrogen storage tank 1 to cool, reheat or cool the introduced working fluid before circulating it to the turbine engine.

[0040] The hydrogen supply assembly includes multiple parallel hydrogen supply branches, each of which is connected to the outlet of a hydrogen storage tank 9. These multiple hydrogen supply branches are connected to a hydrogen supply pipeline in the combustion chamber via a manifold. Each hydrogen supply branch is equipped with a regulating valve 7. The available regulating ratio of the regulating valve 7 on each hydrogen supply branch is greater than a preset ratio threshold. according to Analysis yielded, among which The number of hydrogen supply branches connected to the hydrogen supply line to the combustion chamber. , This represents the maximum required total hydrogen flow rate for the combustion chamber. Minimum required total hydrogen flow rate for the combustion chamber.

[0041] In this embodiment, multi-branch high-precision metering is employed to meet the wide-range high-precision flow regulation requirements. The flow capacity of each branch is determined using the root method to ensure that the number of hydrogen supply branches, the available regulation ratio of regulating valve 7, and the overall flow regulation ratio requirements are matched, while also addressing the issue of high-precision fuel delivery over an extremely wide flow regulation range. A circulating coupled heat exchanger 6 is used to rationally utilize the system's waste heat to raise the hydrogen fuel temperature to a suitable level for combustion, increasing the physical enthalpy of the fuel entering the combustion chamber. This achieves rational optimization of the system's heat / energy utilization, reduces fuel consumption, and improves cycle thermal efficiency. The hydrogen temporary storage tank 9 solves the problem of mismatch between the upstream liquid hydrogen pump and heat exchanger supply flow rate and the downstream regulating valve 7's required flow rate during the transient process of fuel flow regulation due to the lag in the heat exchange process.

[0042] In this embodiment, among the multiple parallel hydrogen supply branches, the design flow range of each hydrogen supply branch is as follows: ,in For the first The available adjustment ratio of regulating valve 7 on each hydrogen supply branch. This ensures that the flow regulation range of each hydrogen supply branch does not exceed the available regulation ratio range of the high-precision regulating valve 7.

[0043] In this embodiment, a hydrogen-oil heat exchanger 8 is also installed on the pipeline between the circulating coupling heat exchanger 6 and the hydrogen storage tank 9. This heat exchanger introduces turbine engine lubricating oil into the hydrogen-oil heat exchanger 8, where hydrogen fuel is used to cool the introduced lubricating oil. The hydrogen-oil heat exchanger 8 not only effectively reduces the temperature of the lubricating oil, ensuring the normal operating temperature range of the turbine engine lubricating oil and extending its service life, but also utilizes the low-temperature characteristics of hydrogen fuel to achieve secondary energy utilization, further improving the energy efficiency of the entire system and providing strong support for the stable operation of the aero-engine.

[0044] Based on the same inventive concept, this embodiment also provides a control method for an aircraft engine liquid hydrogen fuel delivery system, the method comprising:

[0045] When the total hydrogen supply flow rate requirement of the combustion chamber is At that time, only turn on The regulating valve 7 of the hydrogen supply branch corresponding to the minimum value is adjusted according to the total hydrogen supply flow requirement of the combustion chamber. Hydrogen is supplied to the main combustion chamber; The coefficient is and its value range is . ;

[0046] When the total hydrogen supply flow rate requirement of the combustion chamber is At that time, only turn on The regulating valve 7 of the hydrogen supply branch corresponding to the maximum value is adjusted according to the total hydrogen supply flow requirement of the combustion chamber. Hydrogen is supplied to the main combustion chamber;

[0047] when At that time, multiple hydrogen supply branches work in parallel. Taking the flow rate of each hydrogen supply branch as input, the optimization objective is to minimize the overall error of all hydrogen supply branches, and solve the flow distribution of each hydrogen supply branch.

[0048] Example 2

[0049] A liquid hydrogen fuel delivery system for an aircraft engine, comprising:

[0050] Liquid hydrogen storage tank 1, used to store liquid hydrogen fuel;

[0051] Hydrogen temporary storage tank 9 is connected to liquid hydrogen storage tank 1 via a pipeline;

[0052] The circulating coupling heat exchanger 6 is installed on the pipeline between the liquid hydrogen storage tank 1 and the hydrogen temporary storage tank 9. It is used to introduce the working fluid of the turbine engine into the circulating coupling heat exchanger 6, and use the hydrogen fuel output from the liquid hydrogen storage tank 1 to cool, reheat or cool the introduced working fluid before circulating it to the turbine engine.

[0053] The hydrogen supply assembly includes multiple parallel hydrogen supply branches, each of which is connected to the outlet of a hydrogen storage tank 9. These multiple hydrogen supply branches are connected to a hydrogen supply pipeline in the combustion chamber via a manifold. Each hydrogen supply branch is equipped with a regulating valve 7. The available regulating ratio of the regulating valve 7 on each hydrogen supply branch is greater than a preset ratio threshold. according to Analysis yielded, among which The number of hydrogen supply branches connected to the hydrogen supply line to the combustion chamber. , This represents the maximum required total hydrogen flow rate for the combustion chamber. Minimum required total hydrogen flow rate for the combustion chamber.

[0054] The component composition and pipeline connection relationships of the aircraft engine liquid hydrogen fuel delivery system in this embodiment are as follows: Figure 1 As shown. The main features are as follows:

[0055] Submersible liquid hydrogen pump 2 is arranged at the bottom of liquid hydrogen storage tank 1 to ensure the liquid phase conditions at the inlet of liquid hydrogen pump and reduce the risk of liquid hydrogen pump cavitation.

[0056] A filter 3 is installed at the outlet of the submersible liquid hydrogen pump 2 to filter out contaminants that may be introduced by the wear and tear of the liquid hydrogen pump during operation, so as to avoid affecting downstream valves, heat exchangers, nozzles and other components.

[0057] A shut-off valve 4 is installed at the outlet of liquid hydrogen storage tank 1 or downstream of liquid hydrogen pump and at the outlet of metering regulating valve 7, so as to close the delivery channel from the source and the terminal (combustion chamber nozzle 12) as needed to prevent the unexpected flow and diffusion of hydrogen fuel.

[0058] Three-way valves 5 are installed at each pipeline branch to allow for selection and setting of pipeline branch connections as needed, forming functional channels for hydrogen supply, purging, or venting.

[0059] The circulating coupling heat exchanger 6 is set up to heat liquid hydrogen on one hand, and at the same time use liquid hydrogen to cool the working fluid of the turbine engine through intercooling / reheating / cooling gas, so as to realize the comprehensive energy and thermal management of the turbine engine and improve the cycle thermal efficiency.

[0060] Multiple regulating valves 7 are installed to adjust the flow capacity of their respective passages as needed, thereby achieving flow regulation and distribution;

[0061] A hydrogen-oil heat exchanger 8 is installed to cool the turbine engine oil. Due to the large flow range of hydrogen fuel in the engine, the fuel after passing through the circulation coupling heat exchanger 6 is divided into two paths. One path goes through the hydrogen-oil heat exchanger 8 to the hydrogen storage tank 9, and the other path bypasses to the hydrogen storage tank 9. Both paths are equipped with regulating valves 7.

[0062] The hydrogen storage tank 9 stores an appropriate amount of hydrogen fuel that has been heated by heat exchange, and is equipped with temperature sensor 16 and pressure sensor 17 to monitor the medium parameters of the hydrogen storage tank 9, maintaining it within an appropriate pressure and temperature range. When the pressure exceeds the set safety pressure, the three-way valve 5 can be adjusted to allow the hydrogen to flow to the vent flame arrester 13 for safe discharge, or to flow to the liquid hydrogen storage tank 1 to replenish the pressure drop in the tank caused by the consumption of liquid hydrogen.

[0063] Downstream of the hydrogen storage tank 9 are multiple parallel metering and regulation circuits for hydrogen supply branches (≥2 circuits). Each circuit consists of a pressure regulating valve 10, a regulating valve 7, an upstream temperature sensor 16, a pressure sensor 17, and an downstream pressure and temperature sensor 16. Each circuit achieves precise metering of the fuel flow rate through it based on the characteristics and opening degree of the regulating valve 7, the upstream and downstream temperatures and pressures, and the corresponding hydrogen fuel physical properties.

[0064] In this embodiment, the maximum value (i.e., the maximum demand value of the total hydrogen supply flow in the combustion chamber) and the minimum value (i.e., the minimum demand value of the total hydrogen supply flow in the combustion chamber) of the system's total flow regulation target are respectively denoted as... and The total flow regulation ratio is The available control ratio of each branch valve and the selectable flow range ratio of the sensor to meet accuracy requirements are denoted as follows: The number of branch circuits is denoted as n (n≥2). They should satisfy the following relationship to ensure that the branch circuit adjustment range does not exceed the available adjustment range of the high-precision valve and sensor. .

[0065] Among them, the first of the parallel metering and regulation links downstream of hydrogen temporary storage tank 9 The flow rate adjustment range of each branch is ,in For the first The available adjustment ratio of regulating valve 7 on each hydrogen supply branch. .

[0066] Multiple temperature sensors 16, pressure sensors 17, and mass flow meters 18 are installed to monitor the parameters of the medium along the conveying process and provide input for control and regulation.

[0067] The check valve 11 is located near the upstream of the combustion chamber nozzle 12 to minimize the risk and impact of backfire / gas backflow in abnormal situations.

[0068] Flame arresters 13 are installed at the outlets of each venting pipeline to ensure the safety of hydrogen fuel venting and prevent accidental combustion and backfire.

[0069] High-pressure nitrogen cylinder 14 is used to store compressed nitrogen for purging residual hydrogen fuel in the hydrogen fuel delivery system before or after operation.

[0070] Helium storage tank 15 is used to store compressed helium for pressurization during the fuel consumption process of liquid hydrogen storage tank 1.

[0071] The cryogenic insulated pipeline 19 is used for pipeline transportation of liquid hydrogen fuel to avoid the risk of gas lock, equipment frost, solid air / solid oxygen, etc. caused by the direct thermal exposure of liquid hydrogen to the environment, which may lead to unexpected vaporization.

[0072] Conventional pipeline 20 is used for the transportation of non-liquid hydrogen and non-cryogenic media.

[0073] This embodiment takes the case where the number of hydrogen supply branches in the downstream parallel metering stage of hydrogen storage tank 9 is n=2 as an example. The process of implementing the branch flow distribution and metering adjustment using the accuracy-first strategy during operation is as follows:

[0074] 1) Offline calibration: Perform at least 5 points of actual flow calibration on each of the two branches to obtain the relative error curve of the branch with lower flow rate. Relative error curve of high-flow branch ,in The flow ratio of each hydrogen supply branch , Simultaneously, the valve opening-flow curves of each hydrogen supply branch were recorded. , .

[0075] 2) Algorithm Logic: The algorithm logic is designed to control the on / off state of branches based on the relationship between demand flow and the branch's high-precision control capability. The core rule is:

[0076] When the demand flow is very small and does not exceed the allowable ratio (taking 10% as an example) of the maximum controllable flow of the small branch, only the small branch is opened to adjust to the demand flow, while the large branch is completely closed.

[0077] When the demand is very large, exceeding a certain value (such as 95% of the maximum controllable flow of the large branch + 10% of the flow of the small branch), only the large branch will be opened, while the small branch will be completely closed.

[0078] When the two intervals mentioned above are in parallel, the flow distribution of the large and small branches is optimized by solving for the minimum comprehensive error.

[0079] The analytical expression for "minimum comprehensive error" is:

[0080]

[0081] in:

[0082] Indicates the temporary variable Seeking Excellence The expression within the function (i.e., the objective function) is minimized;

[0083] —Used to solve for the overall error, i.e., the temporary flow variables of the objective function;

[0084] —When the objective function reaches its minimum value ;

[0085] —Combustion chamber flow rate requirement;

[0086] -- Maximum controllable flow rate of large branching (=100%FS,l);

[0087] —Maximum controllable flow rate of small branch (=100%FS,s);

[0088] —The relative error curve of the large-scale instrument and the actual flow rate With maximum flow The ratio is related to the relative flow rate: , (%RD);

[0089] —The relative error curve of the small-circuit instrument and the actual flow rate With maximum flow The ratio is related to the relative flow rate: , (%RD);

[0090] —The flow variables corresponding to the branch;

[0091] —The minimum allowable percentage of the FS (generally taken as 10% → α=0.1);

[0092] The pseudocode for the algorithm's logic process is as follows:

[0093] if / / Minimal flow

[0094] ;

[0095] ;

[0096] elseif / / Extremely high flow

[0097] ;

[0098] ;

[0099] else / / Middle area

[0100] ;

[0101] ;

[0102] endif

[0103] in, — Switch hysteresis (to prevent chattering, generally 5% → β = 0.05);

[0104] ——Optimal flow rate of the smaller branch (to be determined)

[0105] ——Optimal large-path flow .

[0106] because , It is a 1-D lookup table (one-dimensional lookup table). The above argmin can be exhaustively searched with a step size of 0.1%, and convergence can be achieved with no more than 50 points.

[0107] 3) Valve Position Correction: If the valve characteristics of the parallel metering and regulating links downstream of hydrogen storage tank 9 are known, a "valve position offset penalty" can be added: J=ΣQ·ε+γ·|hs–50%|+γ·|hl–50%|, where J is the comprehensive objective function to be optimized; ΣQ·ε represents the sum of the products of the flow rate and relative error of each branch, i.e., the total flow error; γ represents the valve position penalty weight coefficient (generally taken as 0.1 to 0.5, the larger the value, the closer the valve is to the middle section); hs represents the current opening degree (percentage) of the valve in the small branch; hl represents the current opening degree of the valve in the large branch. This makes the valve work in the middle section, improving its lifespan and response speed.

[0108] The principle behind improving cycle efficiency through the cycle coupling heat exchanger 6 is to utilize the system's waste heat to raise the temperature of the hydrogen fuel to a suitable level for combustion, thereby increasing the physical enthalpy of the fuel entering the combustion chamber. Taking a regenerative coupling cycle as an example, the liquid hydrogen fuel is reheated using engine exhaust gas before being supplied to the combustion chamber, keeping the combustion chamber outlet temperature constant. This results in improved fuel consumption and cycle thermal efficiency compared to the non-regenerative cycle.

[0109] Figure 2This diagram illustrates the component and pipeline connections in the liquid hydrogen fuel delivery system for an aero-engine according to the present invention. Liquid hydrogen fuel is pressurized from the liquid hydrogen storage tank 1 by a submersible liquid hydrogen pump 2, and then delivered to the circulating coupling heat exchanger 6 via a filter 3, a closed shut-off valve 4, and a three-way valve 5. The fuel then splits into two paths: one flows through a hydrogen-oil heat exchanger 8 to a hydrogen storage tank 9, and the other flows directly to the hydrogen storage tank 9. After passing through multiple parallel flow metering and regulating branches (pressure regulating valve 10, regulating valve 7), the fuel converges and is then delivered to the combustion chamber nozzle 12 via a shut-off valve 4 and a check valve 11 (or, if a one-way valve is used). During this process, temperature, pressure, and mass flow rate are monitored before and after the heat exchange process, after mixing in the hydrogen storage tank 9, and before and after the metering and regulating valve 7.

[0110] Figure 3 After the engine is shut down, the hydrogen fuel delivery system of this invention operates in a safe purging state—the schematic diagram of the connection between the components and pipelines of the purging heat exchange and metering links is shown. In this state, the valve of the venting channel is open, and the valves in the same direction of the combustion chamber nozzle 12 and the liquid hydrogen storage tank 1 are closed. The high-pressure nitrogen cylinder 14 purges and vents the components such as the heat exchange link, the hydrogen temporary storage tank 9, and the metering and regulating link through the pipeline.

[0111] Figure 4 After the engine is stopped, the hydrogen fuel delivery system of this invention operates in a safe purging state—the schematic diagram of the component and pipeline connection for purging the combustion chamber nozzle. In this state, the valve of the venting channel is open, and the valves in the same direction as the combustion chamber nozzle 12 and the liquid hydrogen storage tank 1 are closed. The high-pressure nitrogen cylinder 14 purges and vents the heat exchange link, hydrogen temporary storage tank 9, metering and regulating link and other components through the pipeline.

[0112] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A liquid hydrogen fuel delivery system for an aircraft engine, characterized in that, include: Liquid hydrogen storage tanks are used to store liquid hydrogen fuel; A hydrogen temporary storage tank is connected to the liquid hydrogen storage tank via a pipeline; A circulating coupling heat exchanger is installed on the pipeline between the liquid hydrogen storage tank and the hydrogen temporary storage tank. It is used to introduce the working fluid of the turbine engine into the circulating coupling heat exchanger, and to use the hydrogen fuel output from the liquid hydrogen storage tank to cool, reheat or cool the introduced working fluid before circulating it to the turbine engine. The hydrogen supply assembly includes multiple parallel hydrogen supply branches, each of which is connected to the outlet of a hydrogen storage tank. These multiple hydrogen supply branches are connected to a hydrogen supply pipeline to the combustion chamber via a manifold. Each hydrogen supply branch is equipped with a regulating valve; the available regulating ratio of the regulating valve on each hydrogen supply branch is greater than a preset ratio threshold. according to Analysis yielded, among which The number of hydrogen supply branches connected to the hydrogen supply line to the combustion chamber. , This represents the maximum required total hydrogen flow rate for the combustion chamber. Minimum required total hydrogen flow rate for the combustion chamber.

2. The liquid hydrogen fuel delivery system for aero-engines according to claim 1, characterized in that, In a series of parallel hydrogen supply branches, the design flow range of each hydrogen supply branch is: ,in For the first The available adjustment ratio of the regulating valve on each hydrogen supply branch. .

3. The liquid hydrogen fuel delivery system for aero-engines according to claim 1, characterized in that, A hydrogen-oil heat exchanger is also installed on the pipeline between the circulating coupling heat exchanger and the hydrogen storage tank, which is used to introduce turbine engine lubricating oil into the hydrogen-oil heat exchanger and use hydrogen fuel to cool the introduced lubricating oil.

4. The liquid hydrogen fuel delivery system for aero-engines according to claim 3, characterized in that, The outlet end of the circulating coupling heat exchanger is provided with two branch lines. One branch line goes through the hydrogen-lubricating oil heat exchanger to the hydrogen storage tank, and the other branch line bypasses to the hydrogen storage tank. Both branch lines are equipped with regulating valves.

5. The liquid hydrogen fuel delivery system for an aircraft engine according to claim 1, characterized in that, It also includes at least one venting pipe, on which a venting flame arrester is installed.

6. The liquid hydrogen fuel delivery system for an aircraft engine according to claim 5, characterized in that, It also includes a nitrogen source for purging the pipeline between the liquid hydrogen storage tank and the hydrogen temporary storage tank, the hydrogen supply branch, and the manifold.

7. The liquid hydrogen fuel delivery system for an aircraft engine according to claim 6, characterized in that, Three-way valves are installed at each pipeline branch point to select and set the connection status of the pipeline branch as needed, forming functional channels for hydrogen supply, purging, venting, etc.

8. A control method for an aircraft engine liquid hydrogen fuel delivery system, the method being based on the aircraft engine liquid hydrogen fuel delivery system according to any one of claims 2-7, characterized in that, include: When the total hydrogen supply flow rate requirement of the combustion chamber is At that time, only turn on The regulating valve of the hydrogen supply branch corresponding to the minimum value is adjusted according to the total hydrogen supply flow requirement of the combustion chamber. Hydrogen is supplied to the main combustion chamber; The coefficient is and its value range is . ; When the total hydrogen supply flow rate requirement of the combustion chamber is At that time, only turn on The regulating valve of the hydrogen supply branch corresponding to the maximum value is based on the total hydrogen supply flow requirement of the combustion chamber. Hydrogen is supplied to the main combustion chamber; when At that time, multiple hydrogen supply branches work in parallel. Taking the flow rate of each hydrogen supply branch as input, the optimization objective is to minimize the overall error of all hydrogen supply branches, and solve the flow distribution of each hydrogen supply branch.

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