An aircraft on-board liquid hydrogen inventory monitoring method and system

Abstract

The present application relates to the technical field of fuel cell, disclose a kind of aviation airborne liquid hydrogen balance monitoring method and system, and liquid hydrogen balance monitoring method is specifically as follows: real-time acquisition pressure data of pressure sensor on the left and right side support structure of airborne liquid hydrogen storage tank and the flow data of flowmeter at the outlet of storage tank;Then the collected pressure data and flow data are fused by Kalman filtering, the calculation method of the liquid hydrogen balance in storage tank is determined based on the data fusion result, the calculation method includes calculating the liquid hydrogen balance based on pressure data and calculating the liquid hydrogen balance based on flow data;Finally, the liquid hydrogen balance in storage tank is obtained according to the determined liquid hydrogen calculation method, and the liquid hydrogen balance calculation result is output and the liquid hydrogen cumulative discharge is updated.The present application combines the advantages of weighing method and flowmeter method, realizes high-precision, low-power liquid hydrogen balance monitoring through multi-sensor fusion technology.

Description

Technical Field

[0001] This invention relates to the field of fuel cell technology, and more particularly to the monitoring of liquid hydrogen balance in fuel cells, and more specifically to an airborne liquid hydrogen balance monitoring method and system. Background Technology

[0002] Liquid hydrogen, as an important fuel, has wide applications in aerospace and other fields. Accurate monitoring of the remaining liquid hydrogen in the tank is crucial for the safety and efficient operation of aircraft. Currently, the commonly used methods for monitoring the remaining liquid hydrogen in a liquid hydrogen system are mainly the following two: (1) Direct weighing method: The direct weighing method, which is often used in ground testing, determines the remaining liquid hydrogen by weighing the total weight of the liquid hydrogen tank. Although this method is accurate, it is greatly limited when applied to aircraft, mainly because aircraft will experience various acceleration and attitude changes during flight, making it difficult for the weighing sensor to work stably. (2) Flow meter method: Flow meters are installed at the liquid hydrogen supply end and the safety valve end, and the remaining liquid hydrogen is monitored by statistically accumulating the discharge. This method requires a low-power external heating element at the safety valve vent to maintain the temperature of the discharged gas and ensure the accuracy of the flow meter. However, this method also faces certain challenges when applied to aircraft, mainly due to the influence of pipeline length and ambient temperature changes on the flow meter measurement accuracy.

[0003] Existing technologies primarily rely on the two methods mentioned above to monitor the remaining capacity of liquid hydrogen systems, but both have their limitations. On aircraft, in particular, the need to address changes in vertical acceleration makes it challenging to apply ground-based detection methods in the air. Summary of the Invention

[0004] To address the problems and shortcomings of existing technologies, this invention proposes an airborne liquid hydrogen balance monitoring method and system suitable for aircraft. This invention combines the advantages of the weighing method and the flow meter method, and achieves high-precision, low-power liquid hydrogen balance monitoring through multi-sensor fusion technology.

[0005] To achieve the above-mentioned objectives, the technical solution of the present invention is as follows:

[0006] This invention discloses a method for monitoring the residual amount of liquid hydrogen on an aircraft, the method comprising the following steps:

[0007] Step S1. Real-time acquisition of pressure data from pressure sensors on the support structure of the airborne liquid hydrogen storage tank and flow data from flow meters at the tank outlet; wherein, pressure sensors are symmetrically installed on the support structures on the left and right sides of the liquid hydrogen storage tank, with one pressure sensor installed at the upper and lower ends of each support structure.

[0008] Step S2. The collected pressure and flow data are fused using Kalman filtering. Based on the data fusion result, the calculation method for the liquid hydrogen balance in the storage tank is determined. The calculation method for the liquid hydrogen balance includes calculating the liquid hydrogen balance based on pressure data and calculating the liquid hydrogen balance based on flow data.

[0009] The process of calculating the liquid hydrogen balance based on pressure data is as follows:

[0010] Based on the collected pressure data, a spatial distribution model of liquid hydrogen inside the storage tank is constructed, and the actual liquid hydrogen level height inside the storage tank is calculated.

[0011] The remaining liquid hydrogen in the storage tank is calculated based on the actual liquid hydrogen level. The calculation methods for the actual liquid hydrogen level and the remaining liquid hydrogen in the storage tank are as follows:

[0012] Equation (5);

[0013] Equation (6);

[0014] In the formula, h This represents the actual liquid hydrogen level in the liquid hydrogen storage tank. P s This is the static pressure component. For the longitudinal acceleration of the aircraft, The density of liquid hydrogen in the liquid hydrogen storage tank. The effective cross-sectional area of ​​the liquid hydrogen storage tank. g It is the acceleration due to gravity. The mass of liquid hydrogen in the storage tank based on pressure data;

[0015] The process of calculating the liquid hydrogen balance based on flow data is as follows:

[0016] The collected flow rate data is corrected using temperature compensation to obtain corrected flow rate data. Then, the remaining liquid hydrogen in the storage tank is calculated by integrating the corrected flow rate data over time. The calculation method for obtaining the corrected flow rate data through temperature compensation is as follows:

[0017] Equation (7);

[0018] In the formula, Temperature coefficient; For reference temperature, P r For reference pressure; This represents the actual pressure of liquid hydrogen inside the liquid hydrogen storage tank. Ambient temperature; The flow rate measured by the flow meter; The corrected flow rate;

[0019] Step S3. Obtain the remaining liquid hydrogen in the storage tank according to the determined liquid hydrogen calculation method, output the liquid hydrogen remaining calculation result and update the cumulative liquid hydrogen discharge.

[0020] Preferably, the collected pressure and flow data are fused using Kalman filtering, and the method for calculating the remaining liquid hydrogen in the storage tank is determined based on the fusion result. Specifically:

[0021] When the fusion threshold of pressure data and flow data is less than 5%, the remaining liquid hydrogen in the storage tank is calculated using pressure data.

[0022] When the fusion threshold of pressure data and flow data is ≥5% and the acceleration is >2 g At that time, the corrected flow rate data is used to calculate the remaining liquid hydrogen in the storage tank;

[0023] When the fusion threshold of pressure and flow data is ≥5% and the temperature change is >10℃, the remaining liquid hydrogen in the storage tank is calculated using pressure data.

[0024] Preferably, during data fusion, the flow data used is the flow data after temperature compensation correction.

[0025] As a preferred embodiment, the longitudinal acceleration of the aircraft is calculated as follows:

[0026] Equation (4);

[0027] In the formula, This represents the average reading of two pressure sensors located at the upper ends of the support structures on both sides. This represents the average reading of two pressure sensors located at the lower ends of the supporting structures on both sides. H This refers to the height of the liquid hydrogen storage tank.

[0028] Preferably, the static pressure component is calculated as follows:

[0029] When the liquid level in the liquid hydrogen storage tank changes, the relationship between the pressure difference on the left and right sides and the acceleration can be expressed as:

[0030] Equation (1);

[0031] Based on the relationship between the pressure difference between the left and right sides and acceleration, the lateral acceleration of the aircraft is calculated as follows:

[0032] Equation (2);

[0033] Based on the aircraft's lateral acceleration, the static pressure component is calculated as follows:

[0034] Equation (3);

[0035] In the formula, For the lateral acceleration of the aircraft, The lateral spacing of the pressure sensors. H The height of the liquid hydrogen storage tank. This represents the difference between the upper and lower pressure sensors on the left support structure. This represents the difference between the upper and lower pressure sensors on the right-side support structure.

[0036] Preferably, the effective cross-sectional area of ​​the liquid hydrogen storage tank is calculated as follows:

[0037] A ( h )=π r 2 / cos θ Equation (8);

[0038] In the formula, θ This represents the current attitude angle of the aircraft. r Let be the radius of the liquid hydrogen storage tank.

[0039] Preferably, the flow meter is a thermal flow meter.

[0040] Preferably, a heating element is installed at the pipe outlet near the flow meter.

[0041] Based on the same inventive concept, another aspect of the present invention discloses an airborne liquid hydrogen balance monitoring system, which is used to implement the above-mentioned liquid hydrogen balance monitoring method, specifically including:

[0042] Pressure sensors are symmetrically installed on the support structures on the left and right sides of the liquid hydrogen storage tank. Each support structure has a pressure sensor at the top and bottom to collect pressure data from the support structures on the left and right sides.

[0043] A flow meter is installed at the outlet of the liquid hydrogen storage tank to collect liquid hydrogen flow data at the outlet.

[0044] The data fusion module receives pressure data transmitted from the pressure sensor and flow data transmitted from the flow meter, and fuses the pressure data and flow data through Kalman filtering;

[0045] The data processing module determines the target calculation method from the liquid hydrogen balance calculation methods based on pressure data and flow data based on the data fusion results, and obtains the liquid hydrogen balance in the storage tank according to the target calculation method.

[0046] The output module outputs the liquid hydrogen balance calculation results and updates the cumulative liquid hydrogen emissions.

[0047] The beneficial effects of this invention are:

[0048] 1. This invention, by combining pressure and flow sensors and employing data fusion and error assessment techniques, achieves high-precision, low-power liquid hydrogen balance monitoring, eliminating acceleration and temperature interference during aircraft flight, and is suitable for operating conditions from -50℃ to 50℃. Specifically, the optimized layout of the pressure sensor reduces the liquid level measurement error to <1%, and the flow meter error from ±5% to ±2%, enhancing stability and reliability. This layout optimization effectively adapts to the complex environmental changes encountered during flight. Furthermore, by optimizing sensor placement and using low-power components, this invention reduces system power consumption and simplifies structure and maintenance requirements.

[0049] 2. This invention directly calculates lateral acceleration through the pressure difference between the left and right sides of the aircraft's support structure, which can counteract the inertial force caused by aircraft maneuvering. Furthermore, pressure sensors at the upper and lower ends of the support structure simultaneously monitor longitudinal acceleration interference, making the liquid hydrogen balance calculated from the pressure data more accurate. Compared to sensors installed on only one side or at the bottom, this invention effectively separates acceleration and liquid level signals, eliminating errors caused by liquid sloshing within the storage tank.

[0050] 3. The symmetrical layout of the pressure sensor in this invention can avoid errors caused by violent sloshing of liquid hydrogen due to the high maneuverability of the aircraft. The liquid level height in the storage tank can be reconstructed based on the pressure data measured by the symmetrical layout, ensuring measurement stability under complex attitudes. Attached Figure Description

[0051] The foregoing and hereinafter detailed description of the invention becomes clearer when read in conjunction with the following drawings, in which:

[0052] Figure 1 This is a flowchart of the method of the present invention;

[0053] Figure 2 This is a system architecture diagram of the present invention;

[0054] Figure 3 This is a schematic diagram of the liquid hydrogen storage tank of the present invention. Detailed Implementation

[0055] To enable those skilled in the art to better understand the technical solutions of this invention, specific embodiments will be used to further illustrate the technical solutions for achieving the objectives of this invention. It should be noted that the technical solutions claimed by this invention include, but are not limited to, the following embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort should fall within the scope of protection of this invention.

[0056] There are two main methods for monitoring the remaining capacity of liquid hydrogen systems: direct weighing and flow metering. While these methods meet accuracy and reliability requirements for ground applications, they present significant technical challenges and limitations when used on aircraft.

[0057] (1) Direct weighing is difficult to achieve stable and accurate measurements during aircraft flight. During flight, aircraft experience various acceleration and attitude changes, which can cause significant fluctuations in the measured values ​​of the weighing sensor. Even with high-precision weighing sensors, it is difficult to eliminate the influence of flight conditions on the measurement results, resulting in a decrease in the accuracy of margin monitoring. In addition, the installation and use of weighing sensors on aircraft are also difficult, requiring complex fixing and calibration devices, which increases the complexity of the system and maintenance costs.

[0058] (2) Although the flowmeter method can monitor the liquid hydrogen balance by statistically accumulating emissions, its accuracy decreases in practical applications due to fluctuations in ambient temperature and pipeline length. The flowmeter requires a low-power external heating element at the safety valve vent to maintain the temperature of the emitted gas and ensure measurement accuracy. However, during flight, changes in pipeline length and ambient temperature significantly impact the flowmeter's measurement accuracy, especially in long pipelines and low-temperature environments, where measurement errors increase substantially. Furthermore, the flowmeter method requires additional heating devices, which not only increases system power consumption but also adds complexity and the risk of failure.

[0059] The two methods described above are primarily designed for ground environments, resulting in complex systems, high power consumption, and poor environmental adaptability, making them unsuitable for the complex and ever-changing flight environments of aircraft. During flight, aircraft not only need to cope with changes in vertical acceleration but also with vibration and attitude variations. These factors adversely affect the measurement accuracy and reliability of margin monitoring devices. Existing monitoring methods struggle to maintain stable measurement performance during flight, failing to meet the high-precision and high-reliability margin monitoring requirements of aircraft.

[0060] Therefore, existing liquid hydrogen balance monitoring methods suffer from technical problems such as low measurement accuracy, high system complexity, high power consumption, and poor environmental adaptability in aircraft applications. There is an urgent need for a high-precision liquid hydrogen balance monitoring device that can overcome these shortcomings and is suitable for aircraft environments.

[0061] Therefore, this invention discloses an airborne liquid hydrogen balance monitoring method and system, which is particularly suitable for monitoring the liquid hydrogen balance in hydrogen-oxygen fuel cell systems of aircraft. This embodiment first discloses an airborne liquid hydrogen balance monitoring method, such as... Figure 3As shown, pressure sensors are first symmetrically installed on the left and right support structures of the airborne liquid hydrogen storage tank via dedicated interfaces. Pressure sensors are symmetrically installed at both the upper and lower ends of each support structure, resulting in a total of four pressure sensors installed on the tank. The optimized placement of the pressure sensors accurately reflects the distribution of liquid hydrogen within the tank, providing precise pressure measurements.

[0062] Furthermore, the flow meter is installed at the outlet of the liquid hydrogen storage tank, and a flange connection is used to ensure airtightness. The flow meter can monitor the liquid hydrogen flow rate at the tank outlet in real time, especially accurately recording the cumulative discharge during the liquid hydrogen discharge process. A thermal gas mass flow meter (such as model HJ-FYT-F03) is selected, which features high accuracy and low power consumption, and can adapt to the working environment of the liquid hydrogen tank.

[0063] Furthermore, the heating element is installed on the pipe near the flow meter (before the flow meter) to ensure that the temperature of the discharged gas is maintained during liquid hydrogen discharge. The heating element is powered by an electrical supply and can maintain the pipe outlet temperature within the flow meter's operating range under normal operating conditions. The optimized installation position of the heating element effectively improves the flow meter's measurement accuracy and ensures accurate measurements even in low-temperature environments.

[0064] Based on the above sensor layout, such as Figure 1 As shown, the specific method for monitoring the residual liquid hydrogen onboard aircraft is as follows:

[0065] Step S1. Real-time acquisition of pressure data from four pressure sensors on the support structure of the liquid hydrogen storage tank and flow data from the flow meter at the tank outlet.

[0066] Step S2. The collected pressure and flow data are fused using a Kalman filter algorithm. Based on the data fusion results, the calculation method for the liquid hydrogen balance in the storage tank is determined. The calculation method for the liquid hydrogen balance includes calculating the liquid hydrogen balance based on pressure data and calculating the liquid hydrogen balance based on flow data.

[0067] In this invention, for the Kalman filter algorithm, when performing data fusion, the default state is that the data fusion threshold is <5%, and the Kalman filter uses the initial R=diag(0.52,0.022). The abnormal trigger is that the data fusion threshold is ≥5%.

[0068] For exception triggering:

[0069] Acceleration > 2 g —Determining the pressure data to be invalid—Rpres=2.0;

[0070] Temperature sudden change >10℃ — Flow data deemed invalid — Rflow=2.0;

[0071] Increasing Rpres leads to a decrease in the pressure weight in K, which in turn biases the filtering results towards flow data.

[0072] Increasing Rflow leads to a decrease in the flow weight in K, resulting in a bias in the filtering results towards pressure data.

[0073] Therefore, the specific judgment method and logic for determining the remaining liquid hydrogen in the storage tank based on the data fusion results are as follows:

[0074] When the fusion threshold of pressure data and flow data is less than 5%, the liquid hydrogen balance in the storage tank is calculated using pressure data (to prevent flow temperature drift).

[0075] When the fusion threshold of pressure data and flow data is ≥5% and the acceleration is >2 g At that time, the liquid hydrogen balance in the storage tank was calculated using the corrected flow rate data (pressure is significantly affected by inertial interference).

[0076] When the fusion threshold of pressure data and flow data is ≥5% and the temperature change is >10℃, the remaining liquid hydrogen in the storage tank is calculated using pressure data (flow rate is affected by temperature drift).

[0077] Rpres, Rflow , Both R and K are computational variables in the Kalman filter algorithm; where R=diag(0.52,0.022) represents the initial noise in the observation data update equation of the Kalman filter algorithm; This represents the mean squared error of the traffic data; Rmean square represents the standard deviation of the pressure data; Rpres is the component of the Kalman filter algorithm's observation noise covariance matrix that is related to the pressure data; Rflow is the component of the Kalman filter algorithm's observation noise covariance matrix that is related to the flow rate data; K is the Kalman gain in the Kalman filter algorithm.

[0078] It should be noted that when the data fusion threshold is ≥5%, the Neyman-Pearson criterion is usually used to establish the following hypothesis testing model for testing. When the test statistic exceeds a certain value, the data arbitration mechanism is triggered.

[0079] When the Neyman-Pearson criterion holds

[0080] If the acceleration is greater than 2g, the pressure data is considered invalid. =2.0, As the pressure weight in K increases, the filtering result becomes biased towards flow rate data. Therefore, flow rate data needs to be used to calculate the remaining liquid hydrogen.

[0081] If the temperature change is greater than 10℃, the flow rate data is considered invalid. =2.0, As the pressure increases, the flow rate weight in K decreases, and the filtering results become biased towards pressure data. Therefore, pressure data is needed to calculate the remaining liquid hydrogen.

[0082] The Neyman-Pearson criterion is common knowledge and will not be explained in detail here.

[0083] Step S3. Obtain the high-precision liquid hydrogen balance in the storage tank according to the determined liquid hydrogen calculation method, and finally output the liquid hydrogen balance calculation result and update the cumulative liquid hydrogen discharge.

[0084] In the embodiments described in this invention, the calculation methods for the above two liquid hydrogen balances are as follows:

[0085] (1) Calculate the liquid hydrogen balance based on pressure data

[0086] Based on the collected pressure data, a spatial distribution model of liquid hydrogen inside the storage tank is constructed, and the actual liquid hydrogen level height inside the storage tank is calculated.

[0087] When the liquid level in the liquid hydrogen storage tank changes, the relationship between the pressure difference on the left and right sides of the tank and the acceleration can be expressed as:

[0088] Equation (1);

[0089] Based on the relationship between the pressure difference on the left and right sides of the storage tank and acceleration, the lateral acceleration of the aircraft is obtained. The calculation method is as follows:

[0090] Equation (2);

[0091] Furthermore, the lateral acceleration of the aircraft The static pressure component was obtained from the pressure sensor data on the two supporting structures. P s The calculation method is as follows:

[0092] Equation (3);

[0093] The longitudinal acceleration of the aircraft is obtained based on the values ​​from the pressure sensors on the two supporting structures. a z The calculation method is as follows:

[0094] Equation (4);

[0095] In the formula, For the lateral acceleration of the aircraft, The lateral spacing of the pressure sensors. The density of hydrogen inside the liquid hydrogen storage tank. H The height of the liquid hydrogen storage tank. This represents the average reading of two pressure sensors located at the upper ends of the support structures on both sides. This represents the average reading of two pressure sensors located at the lower ends of the supporting structures on both sides. This represents the difference between the upper and lower pressure sensors on the left support structure. The difference between the upper and lower pressure sensors on the right-side support structure;

[0096] The actual liquid level inside the storage tank was calculated using data such as static pressure component and longitudinal acceleration of the aircraft. h :

[0097] Equation (5);

[0098] Finally, the remaining liquid hydrogen in the storage tank is calculated based on the actual liquid hydrogen level and the effective cross-sectional area of ​​the tank, as follows:

[0099] Equation (6);

[0100] In the formula, The effective cross-sectional area of ​​the liquid hydrogen storage tank. This refers to the mass of liquid hydrogen in the storage tank based on pressure data.

[0101] For the effective cross-sectional area of ​​a liquid hydrogen storage tank, it is usually necessary to consider the correction of the liquid surface cross-sectional area of ​​the tank during aircraft operation. For example, when the drone is tilted, the effective cross-sectional area of ​​a cylindrical tank needs to take into account the current flight attitude angle of the aircraft. θ Therefore, the effective cross-sectional area of ​​a liquid hydrogen storage tank can be calculated using the following formula:

[0102] A ( h )=π r 2 / cos θ Equation (8);

[0103] In the formula, θ This represents the current attitude angle of the aircraft. r Let be the radius of the liquid hydrogen storage tank.

[0104] (2) Calculate the liquid hydrogen balance based on flow rate data

[0105] To avoid interference from two-phase flow and the resulting decrease in flow meter accuracy due to incomplete vaporization of liquid hydrogen, which in turn leads to distortion and significant deviation in the calculation of liquid hydrogen balance using flow data, this invention improves the accuracy of the flow meter data through temperature compensation correction. The following temperature compensation correction formula is established:

[0106] Equation (7);

[0107] In the formula, This is the temperature coefficient, which is 0.0035 for hydrogen. For reference temperature, 273.15K can be used; P r For reference pressure, 101.325 kPa can be taken. This represents the actual pressure of liquid hydrogen inside the liquid hydrogen storage tank. Ambient temperature; The flow rate measured by the flow meter; The corrected flow rate;

[0108] Integrating the corrected flow rate data over time, we finally obtain the remaining liquid hydrogen in the tank based on the flow rate data.

[0109] In this invention, flow meter measurement requires specific temperature conditions. For the selected thermal flow meter, the pipeline temperature needs to be maintained above -10°C. Therefore, a heating element is installed on the outlet pipeline of the liquid hydrogen storage tank. To efficiently control the temperature and minimize heating power, the heating element is installed close to the flow meter. The heating element is integrated near the flow meter to maintain the pipeline outlet temperature ≥ -10°C. The heating power of the heating element is calculated using the pipeline heat balance equation, as follows:

[0110] Equation (9);

[0111] In the formula, C This refers to the heating power of the heating element; is the specific heat capacity of hydrogen; To achieve the target temperature rise; The heat transfer coefficient of the pipeline; B The surface area of ​​the pipeline; For heating efficiency; Ambient temperature; The temperature is the hydrogen temperature (measured by a temperature sensor located on the outlet pipeline of the liquid hydrogen storage tank).

[0112] Based on the same inventive concept, this invention also discloses an airborne liquid hydrogen balance monitoring system, which is used to implement the above-mentioned airborne liquid hydrogen balance monitoring method, such as... Figure 2 As shown, the system architecture is as follows:

[0113] Pressure sensors are symmetrically installed on the support structures on the left and right sides of the liquid hydrogen storage tank. Each support structure has a pressure sensor at the top and bottom to collect pressure data from the support structures on the left and right sides.

[0114] A flow meter is installed at the outlet of the liquid hydrogen storage tank to collect liquid hydrogen flow data at the outlet.

[0115] The data fusion module receives pressure data transmitted from the pressure sensor and flow data transmitted from the flow meter, and fuses the pressure data and flow data through Kalman filtering;

[0116] The data processing module determines the target calculation method from the liquid hydrogen balance calculation methods based on pressure data and flow data based on the data fusion results, and obtains the liquid hydrogen balance in the storage tank according to the target calculation method.

[0117] The output module outputs the liquid hydrogen balance calculation results and updates the cumulative liquid hydrogen emissions.

[0118] Furthermore, this embodiment also provides a computer device, which includes a processor, an input device, an output device, and a memory, all interconnected. The memory stores a computer program, which includes program instructions, and the processor is configured to invoke the program instructions to execute the steps described in the above embodiment.

[0119] Furthermore, another aspect of this embodiment provides a computer-readable storage medium, characterized in that: the computer-readable storage medium stores a computer program, the computer program including program instructions, which, when executed by a processor, cause the processor to perform the steps in the above embodiment.

[0120] In this embodiment, the processor can be a central processing unit (CPU). The processor can also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or combinations of the above types of chips.

[0121] Memory, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs, non-transitory computer-executable programs, and units, such as the program units corresponding to the above-described method embodiments of the present invention. The processor executes various functional applications and data processing of the processor by running the non-transitory software programs, instructions, and modules stored in the memory, thereby implementing the methods described in the above-described method embodiments.

[0122] The memory may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function; the data storage area may store data created by the processor, etc. Furthermore, the memory may include high-speed random access memory and non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, the memory may optionally include memory remotely located relative to the processor, which can be connected to the processor via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0123] The one or more units are stored in the memory and, when executed by the processor, perform the methods described in the above embodiments.

[0124] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects.

[0125] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. An airborne on-board liquid hydrogen quantity monitoring method, characterized in that, Includes the following steps: Step S1. Real-time acquisition of pressure data from pressure sensors on the support structure of the airborne liquid hydrogen storage tank and flow data from flow meters at the tank outlet; wherein, pressure sensors are symmetrically installed on the support structures on the left and right sides of the liquid hydrogen storage tank, with one pressure sensor installed at the upper and lower ends of each support structure. Step S2. The collected pressure data and flow data are fused using Kalman filtering, and the calculation method for the liquid hydrogen balance in the storage tank is determined based on the data fusion result; the calculation method for the liquid hydrogen balance includes calculating the liquid hydrogen balance based on pressure data and calculating the liquid hydrogen balance based on flow data; When the fusion threshold of pressure data and flow data is less than 5%, the remaining liquid hydrogen in the storage tank is calculated using pressure data. When the fusion threshold of pressure data and flow data ≥ 5% and acceleration > 2 g The modified flow data is used to calculate the liquid hydrogen remaining in the tank. When the fusion threshold of pressure and flow data is ≥5% and the temperature abrupt change is >10℃, the remaining liquid hydrogen in the storage tank is calculated using pressure data; where... The process of calculating the liquid hydrogen balance based on pressure data is as follows: Based on the collected pressure data, a spatial distribution model of liquid hydrogen inside the storage tank is constructed, and the actual liquid hydrogen level height inside the storage tank is calculated. The remaining liquid hydrogen in the storage tank is calculated based on the actual liquid hydrogen level. The calculation methods for the actual liquid hydrogen level and the remaining liquid hydrogen in the storage tank are as follows: Formula (5); Formula (6); In the formula, h This represents the actual liquid hydrogen level in the liquid hydrogen storage tank. P s This is the static pressure component. For the longitudinal acceleration of the aircraft, The density of liquid hydrogen in the liquid hydrogen storage tank. The effective cross-sectional area of ​​the liquid hydrogen storage tank. g It is the acceleration due to gravity. The mass of liquid hydrogen in the storage tank based on pressure data; The process of calculating the liquid hydrogen balance based on flow data is as follows: integrate the collected flow data over time to calculate the liquid hydrogen balance in the storage tank. Step S3. Obtain the remaining liquid hydrogen in the storage tank according to the determined liquid hydrogen calculation method, output the liquid hydrogen remaining calculation result and update the cumulative liquid hydrogen discharge.

2. The method for monitoring the residual amount of airborne liquid hydrogen according to claim 1, characterized in that, When calculating the remaining liquid hydrogen volume using flow rate data, the collected flow rate data is corrected for temperature. The corrected flow rate data is then integrated over time to calculate the remaining liquid hydrogen volume in the storage tank. The calculation method for the temperature-compensated flow rate data is as follows: Equation (7); In the formula, Temperature coefficient; For reference temperature, P r For reference pressure; This represents the actual pressure of liquid hydrogen inside the liquid hydrogen storage tank. Ambient temperature; The flow rate measured by the flow meter; This is the corrected flow rate.

3. The method for monitoring the residual amount of airborne liquid hydrogen according to claim 1, characterized in that, During data fusion, the traffic data used is the traffic data after temperature compensation correction.

4. The method for monitoring the residual amount of airborne liquid hydrogen according to claim 1, characterized in that, The longitudinal acceleration of an aircraft is calculated as follows: Equation (4); In the formula, This represents the average reading of two pressure sensors located at the upper ends of the support structures on both sides. This represents the average reading of two pressure sensors located at the lower ends of the supporting structures on both sides. H This refers to the height of the storage tank.

5. The method for monitoring the residual amount of airborne liquid hydrogen according to claim 1, characterized in that, The static pressure component is calculated as follows: When the liquid level in the liquid hydrogen storage tank changes, the relationship between the pressure difference on the left and right sides and the acceleration can be expressed as: Equation (1); Calculate the lateral acceleration of the aircraft based on the relationship between the pressure difference on the left and right sides and acceleration: Equation (2); Calculate the static pressure component based on the aircraft's lateral acceleration: Equation (3); In the formula, For the lateral acceleration of the aircraft, The lateral spacing of the pressure sensors. H The height of the liquid hydrogen storage tank. This represents the difference between the upper and lower pressure sensors on the left support structure. This represents the difference between the upper and lower pressure sensors on the right-side support structure.

6. The method for monitoring the residual amount of airborne liquid hydrogen according to claim 1, characterized in that, The effective cross-sectional area of ​​a liquid hydrogen storage tank is calculated as follows: A ( h )=π r 2 / cos θ formula (8); In the formula, θ This represents the current attitude angle of the aircraft. r Let be the radius of the liquid hydrogen storage tank.

7. The method for monitoring the residual amount of airborne liquid hydrogen according to claim 1, characterized in that, The flow meter is a thermal flow meter.

8. The method for monitoring the residual amount of airborne liquid hydrogen according to claim 1, characterized in that, A heating element is installed at the pipe outlet near the flow meter.

9. An airborne liquid hydrogen balance monitoring system, characterized in that, The liquid hydrogen balance monitoring system is used to implement the liquid hydrogen balance monitoring method according to any one of claims 1-8, including: Pressure sensors are symmetrically installed on the support structures on the left and right sides of the liquid hydrogen storage tank. Each support structure has a pressure sensor at the top and bottom to collect pressure data from the support structures on the left and right sides. A flow meter is installed at the outlet of the liquid hydrogen storage tank to collect liquid hydrogen flow data at the outlet. The data fusion module receives pressure data transmitted from the pressure sensor and flow data transmitted from the flow meter, and fuses the pressure data and flow data through Kalman filtering; The data processing module determines the target calculation method from the liquid hydrogen balance calculation methods based on pressure data and flow data based on the data fusion results, and obtains the liquid hydrogen balance in the storage tank according to the target calculation method. The output module outputs the liquid hydrogen balance calculation results and updates the cumulative liquid hydrogen emissions.

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