A control method of a vehicle-mounted hydrogen fuel cell hydrogen supply system based on working condition self-adaption

Abstract

This invention relates to the field of new energy vehicle technology and discloses a control method for an on-board hydrogen fuel cell hydrogen supply system based on adaptive operating conditions, including the following steps: Step 1: Obtain the pressure value of the high-pressure gas cylinder. P 1 If the pressure value P 1 ≤ P th1 In this case, hydrogen is supplied directly to the fuel cell; Step 2: If P 1 > P th1 Simultaneously detect the pressure change sequence of the high-pressure gas cylinder. P ( t ), to obtain pressure in t Relative rate of change at time If the pressure exceeds the threshold, the system will enter hydrogen circulation pressurization mode; Step 3: Obtain the pressure value inside the gas storage cylinder. P tank If the pressure value P tank > P th2 And the increase in hydrogen storage per unit time ≤ k 3 Then it enters the hydrogen recycling mode; the method of the present invention achieves precise, efficient and stable hydrogen supply for vehicles, and improves the working efficiency and dynamic response capability of fuel cell systems.

Description

A Control Method for On-board Hydrogen Fuel Cell Supply System Based on Operating Condition Adaptation Technical Field

[0001] This invention relates to the field of new energy vehicle technology, specifically to a control method for an on-board hydrogen fuel cell hydrogen supply system based on adaptive operating conditions. Background Technology

[0002] Hydrogen fuel cell vehicles, with their advantages of zero emissions and high energy conversion efficiency, have become an important technological path in the transportation sector. The onboard hydrogen supply system, as the core subsystem of the fuel cell, is responsible for safely, efficiently, and stably regulating the stored gaseous hydrogen to a pressure that meets the requirements of the fuel cell stack inlet and continuously supplying it. Its performance directly determines the vehicle's power response, energy efficiency, and driving range.

[0003] For example, in the prior art, application number 20231071886072 discloses a fuel cell hydrogen supply system and method. This fuel cell hydrogen supply system includes a high-pressure gas cylinder, a first gas path connecting the high-pressure gas cylinder and the fuel cell, a second gas path connected in parallel with the first gas path, and a control component. A vaporization device is provided on the first gas path, and a storage cylinder is provided on the second gas path. The control component includes a controller and several control valves. The controller controls the control valves to control the connection or disconnection of the first and second gas paths, allowing liquid hydrogen in the high-pressure gas cylinder to be transported to the fuel cell via the first gas path. When the pressure of the gaseous hydrogen in the high-pressure gas cylinder exceeds a first preset pressure threshold, the gaseous hydrogen is stored in the storage cylinder via the second gas path and can be supplied to the fuel cell via the second gas path. This fuel cell hydrogen supply system can recover and reuse gaseous hydrogen in the high-pressure gas cylinder that exceeds the first preset pressure threshold, reducing the release of gaseous hydrogen to the outside and reducing resource waste. Although this technical solution has the basic architecture of a dual gas path and a storage cylinder, its control method suffers from a single and passive control logic. This method relies solely on a static condition—pressure exceeding a first preset pressure threshold—to trigger mode switching. This approach suffers from several major problems: First, the system cannot distinguish between brief pressure fluctuations and sustained trend changes, easily leading to frequent mode switching or malfunctions. For example, a momentary pressure exceeding the threshold during slight acceleration or deceleration can trigger unnecessary pressurization, wasting energy and reducing the lifespan of critical components. Second, its pressurization and hydrogen recirculation processes lack precise target control and energy efficiency management. Summary of the Invention

[0004] This invention addresses the problems existing in the prior art by providing a control method for an on-board hydrogen fuel cell hydrogen supply system based on operating condition adaptation.

[0005] The technical solution adopted in this invention is: a control method for an on-board hydrogen fuel cell hydrogen supply system based on adaptive operating conditions, comprising the following steps:

[0006] Step 1: Obtain the pressure value P1 of the high-pressure gas cylinder. If the pressure value P1 ≤ P th1 P th1 If the first preset pressure threshold is met, then direct hydrogen supply mode is used to deliver hydrogen to the fuel cell; otherwise, proceed to step 2.

[0007] Step 2: If P1 > P th1 Simultaneously, the pressure change sequence P(t) of the high-pressure gas cylinder is detected to obtain the relative rate of change of pressure at time t. ,judge If the change threshold k1 is exceeded, the hydrogen circulation pressurization mode is entered and hydrogen is introduced into the storage cylinder; otherwise, the direct hydrogen supply mode continues.

[0008] Step 3: Obtain the pressure value P inside the gas cylinder. tank If the pressure value P tank >P th2 P th2 The second preset pressure threshold, and the increase in hydrogen storage per unit time. If the value is ≤k3, where k3 is a preset threshold, then the hydrogen recycling mode is entered, and the hydrogen in the storage cylinder is delivered to the fuel cell; otherwise, the hydrogen recycling and pressurization mode is maintained.

[0009] Furthermore, in step 2, regarding The weighted average is used to obtain the weighted rate of change of pressure. ;judge Does it exceed the set threshold k2? If it meets the requirements at the same time... >k1, If the value is greater than k2, the system will enter the hydrogen circulation pressurization mode; otherwise, it will continue to operate in the direct hydrogen supply mode.

[0010] Furthermore, a pressurization device is installed in the gas line between the high-pressure gas cylinder and the gas storage cylinder;

[0011] A dynamic calculation model for the newly added pressure target value is constructed, and the target pressure value is controlled by controlling the opening and closing of the pressurization device.

[0012]

[0013] In the formula: For the fuel cell stack inlet pressure requirements, For hydrogen supply pressure differential, Energy efficiency coefficient;

[0014] Controlling the energy efficiency coefficient under hydrogen recirculation pressurization mode of on-board hydrogen fuel cell hydrogen supply system Within the preset range ,like Then shut off the booster device; if If so, the booster device will be activated;

[0015] in:

[0016]

[0017] In the formula: This refers to the energy consumption per unit time of the booster device.

[0018] Furthermore, in step 2, the pressure change sequence P(t) is decomposed into approximate components and detail components using wavelet basis functions; the energy entropy of the detail components is calculated. ,like Less than the preset threshold If the pressure change rate is not found, it is considered noise interference and the calculation of the pressure change rate during that time period is ignored; otherwise, the relative change rate during that time period is calculated.

[0019] Furthermore, a pressurization device is installed in the gas line between the high-pressure gas cylinder and the gas storage cylinder;

[0020] Construct the optimization function for the booster device:

[0021]

[0022] In the formula: The output power of the booster device, The pressure P of the gas cylinder tank With target pressure The deviation, λ is the weighting coefficient, and T is the prediction time domain;

[0023] The booster device is controlled by this optimized function.

[0024] Furthermore, a static mixer is installed in the gas path between the gas storage cylinder and the fuel cell to calculate the Reynolds number Re of hydrogen in the static mixer; if Re is less than a preset value, the eddy current generator built into the static mixer is activated; otherwise, the eddy current generator is turned off.

[0025] Furthermore, the following control processes are also included:

[0026] Construct the judgment function F:

[0027]

[0028] In the formula: P1 is the hydrogen pressure in the high-pressure gas cylinder, T is the hydrogen temperature inside the high-pressure gas cylinder, and Q is the current hydrogen flow rate in the gas path. , , All are weighting coefficients;

[0029] like , If the preset threshold is met, the hydrogen circulation pressurization mode will be activated.

[0030] like , If the preset threshold is met, the direct hydrogen supply mode will be activated.

[0031] Furthermore, a time compensation device is installed in the gas path between the high-pressure gas cylinder, the hydrogen storage tank, and the fuel cell. The response delay time of the time compensation device is as follows:

[0032]

[0033] In the formula: In response to the delay time, This represents the change in pressure of gaseous hydrogen. It is a constant.

[0034] Furthermore, a real-time gas path health status estimation module is also installed in the gas path between the high-pressure gas cylinder, the hydrogen storage tank, and the fuel cell, which estimates the health status using a state-space model.

[0035]

[0036] In the formula: For system status, For the input vector, For the observation vector, and All are observation noise, A is the state transition matrix, B is the input matrix, and H is the observation matrix; The system state at the next moment;

[0037] The system status is estimated in real time using Kalman filtering; if the obtained gas path coefficient is lower than the threshold, an alarm is triggered.

[0038] The beneficial effects of this invention are:

[0039] This invention, by calculating and smoothing the pressure change rate, can keenly detect trend-based pressure changes, such as rapid pressure accumulation caused by a sudden drop in fuel cell power, rather than simply responding to instantaneous pressure fluctuations. This allows the system to proactively activate the hydrogen recirculation boost mode before the pressure actually exceeds safety limits, avoiding drastic pressure fluctuations. Simultaneously, when rapid vehicle acceleration causes a surge in hydrogen demand, pre-stored high-pressure hydrogen in the storage tank can be quickly deployed to supply hydrogen along with the main gas line, providing the system with high-pressure, rapid energy buffering. This ensures instantaneous stability of the hydrogen supply pressure, meeting the stringent requirements of dynamic loads on the fuel cell. Attached Figure Description

[0040] Figure 1 is a schematic diagram of the hydrogen supply system of the present invention.

[0041] Figure 2 is a schematic diagram of the control process of the present invention.

[0042] Figure 3 is a schematic diagram of the control valve and air circuit connection of the present invention.

[0043] Figure 4 is a schematic diagram of the hydrogen supply mode switching logic in this invention. Detailed Implementation

[0044] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0045] As shown in Figure 2, a control method for an on-board hydrogen fuel cell hydrogen supply system based on adaptive operating conditions includes the following steps: the hydrogen supply mode switching logic is shown in Figure 4.

[0046] The hydrogen supply system used is shown in Figures 1 and 3. The hydrogen supply system in this invention can be implemented using existing systems, such as the hydrogen supply system mentioned in the background art.

[0047] The system includes a high-pressure gas cylinder, a first gas path connecting the high-pressure gas cylinder and a fuel cell, a second gas path connected in parallel with the first gas path, and a controller; a gas storage cylinder is provided on the second gas path; the control assembly includes a plurality of control valves respectively disposed on the first and second gas paths, and a controller respectively connected to each of the control valves; the controller controls the plurality of control valves, thereby controlling the connection or disconnection of the first and second gas paths, so that liquid hydrogen in the high-pressure gas cylinder is transported to the fuel cell through the first gas path; the gas storage cylinder can supply gaseous hydrogen to the fuel cell through the second gas path.

[0048] The direct hydrogen supply mode involves supplying hydrogen directly to the fuel cell from a high-pressure gas cylinder;

[0049] The hydrogen circulation pressurization mode involves transferring hydrogen from the high-pressure cylinder into a storage cylinder for storage.

[0050] The hydrogen recycling mode uses hydrogen from the storage cylinder to supply hydrogen to the fuel cell. Of course, if there is not enough hydrogen, a high-pressure cylinder is also needed to supply it.

[0051] In the hydrogen supply system used, the gas path from the high-pressure gas cylinder to the fuel cell is the first gas path; the gas path from the high-pressure gas cylinder to the gas storage cylinder is the second gas path; and the gas path from the gas storage cylinder to the fuel cell is the third gas path.

[0052] Step 1: Obtain the pressure value P1 of the high-pressure gas cylinder. If the pressure value P1 ≤ P th1 P th1 If the first preset pressure threshold is met, then direct hydrogen supply mode is used to deliver hydrogen to the fuel cell; otherwise, proceed to step 2.

[0053] The system monitors the gaseous hydrogen pressure inside the high-pressure cylinder in real time. A pressure sensor located at the cylinder's outlet continuously collects the pressure value. This pressure sensor is connected to a controller, transmitting the collected data in real time to provide a basis for subsequent operational condition assessments. Pressure monitoring of the high-pressure cylinder is fundamental to the hydrogen supply system's ability to adaptively adjust according to operating conditions.

[0054] Step 2: If P1 > P th1 Simultaneously, the pressure change sequence P(t) of the high-pressure gas cylinder is detected to obtain the relative rate of change of pressure at time t. ,judge If the change threshold k1 is exceeded, the hydrogen circulation pressurization mode is entered and hydrogen is introduced into the storage cylinder; otherwise, the direct hydrogen supply mode continues.

[0055] First, define the time series of gaseous hydrogen pressure changes as P(t), where t is time. Within this series, detect whether the gaseous hydrogen pressure is stable or fluctuates around a certain threshold. This process can be measured using the pressure change rate. To achieve, the rate of change of pressure Defined as:

[0056]

[0057] In the formula: This represents the pressure value at the previous moment.

[0058] The above formula is used to calculate the magnitude and direction of changes in gaseous hydrogen pressure, thereby determining the trend of pressure fluctuations.

[0059] The controller needs to determine whether this rate of change exceeds a preset threshold k1. If it does, then... If the pressure changes significantly, the system will enter a hydrogen circulation pressurization mode, introducing hydrogen into the storage cylinder.

[0060] To further improve the response speed and accuracy of the control system, a weighted smoothing process is introduced to filter out noise caused by short-term fluctuations.

[0061] Weighted rate of change of pressure The calculation process is as follows:

[0062]

[0063] In the formula: As a smoothing factor, By adjusting The value of , which determines the sensitivity of the control system to recent fluctuations. Weighted pressure change rate. It is used to balance short-term fluctuations with long-term trends. This represents the weighted rate of change of pressure at the next moment.

[0064] judge Does the pressure exceed the set threshold k2, indicating a significant change? If both conditions are met... >k1, If the value is greater than k2, the system will enter the hydrogen circulation pressurization mode; otherwise, it will continue to operate in the direct hydrogen supply mode.

[0065] The weighted pressure change rate calculated above is designed to ensure the system can flexibly determine when to switch to pressurization mode based on real-time pressure data and trends. Smoothing pressure change data effectively reduces short-term noise fluctuations and avoids overly frequent mode switching. This helps the controller determine whether to adjust the operating mode to ensure the stability and efficiency of hydrogen supply.

[0066] To improve the robustness of pressure trend identification, a multi-scale decomposition method for pressure signals based on wavelet transform is introduced, which decomposes the pressure sequence through wavelet basis functions. Decomposed into approximate components and detail components:

[0067]

[0068] In the formula: a is the scale parameter, b is the translation parameter, It is the conjugate of the wavelet basis functions.

[0069] Calculate the energy entropy of detail components The method for calculating the energy entropy of the detail components is as follows:

[0070] First, calculate the energy entropy of each scale's detail component after wavelet decomposition (i.e., the sum of squares of the wavelet coefficients at the corresponding scale). Then, calculate the probability of each scale's detail component energy relative to the total energy of all detail components. Substitute this probability into the formula for information entropy to calculate the energy entropy of the detail component. The energy entropy of the detail component is used to determine whether pressure fluctuations originate from noise or changes in actual operating conditions. If... Less than the preset threshold If the pressure change rate is not high, it is considered noise interference, and the calculation of the pressure change rate during that time period is ignored to avoid false switching caused by high-frequency interference. Otherwise, the relative change rate during that time period is calculated.

[0071] When the controller detects that the pressure in the high-pressure cylinder does not meet the preset value, the controller activates the hydrogen circulation pressurization mode, closes the connection between the first gas path and the fuel cell, and introduces the gaseous hydrogen in the cylinder into the storage cylinder through the second gas path.

[0072] A pressurization device is installed in the second gas line to pressurize the gaseous hydrogen entering the gas cylinder, thereby improving hydrogen storage efficiency and alleviating excessive pressure inside the cylinder.

[0073] In the hydrogen recirculation pressurization mode, to avoid excessive pressurization leading to energy waste or insufficient pressurization affecting hydrogen supply stability, a new dynamic calculation model for the pressurization target is added to calculate the final target pressure. .

[0074]

[0075] In the formula: For the fuel cell stack inlet pressure requirements, For hydrogen supply pressure differential, This is the energy efficiency coefficient. The real-time hydrogen consumption is calculated based on the fuel cell stack power. The unit is mol / s, combined with the inlet pressure requirements of the fuel cell stack. Unit: MPa; Determine the required hydrogen supply pressure differential. ,when ≤ , The rated hydrogen consumption is expressed in mol / s. Take the base value as 0.2 MPa; when > hour, according to Dynamically increasing to ensure rapid hydrogen supply response under high hydrogen consumption conditions.

[0076] The core input parameters are the current pressure of the gas storage cylinder and the real-time hydrogen consumption of the fuel cell.

[0077] To reduce energy consumption while meeting pressure requirements, the hydrogen supply system dynamically adjusts the operating frequency of the booster unit using an energy efficiency balance algorithm. This method uses the energy efficiency coefficient as the core adjustment indicator.

[0078]

[0079] In the formula: This represents the increase in hydrogen storage capacity per unit time. This refers to the energy consumption per unit time of the booster device.

[0080] The system presets an optimal energy efficiency range. The controller calculates the current energy efficiency coefficient in real time to keep the energy efficiency coefficient within the optimal range and maintain the current operating frequency.

[0081] like If the energy efficiency is too low, the booster device should be turned off. Once the energy efficiency coefficient is within the preset range, the booster device can be started to reduce the operating frequency of the booster device and reduce energy consumption.

[0082] like If the energy consumption is high but the hydrogen storage speed may be insufficient, the booster device should be started. Once the energy efficiency coefficient is within the preset range, the booster device can be shut down to increase the operating frequency and accelerate hydrogen storage.

[0083] Through this closed-loop regulation mechanism, the system achieves a dynamic balance between energy consumption and hydrogen storage efficiency while ensuring hydrogen supply pressure.

[0084] To further optimize the dynamic response of the pressurization process, a model predictive control-based adaptive power adjustment method for the pressurization device is introduced, using the gas cylinder pressure P... tank With target pressure deviation To control the input, solve the following optimization function:

[0085]

[0086] In the formula: , The output power of the booster device, λ represents the output power of the booster device, λ is the weighting coefficient, and T is the prediction time domain.

[0087] The controller dynamically adjusts the function by solving the optimization function in real time. , making P tank Approaching quickly with minimal energy consumption Simultaneously, load current feedforward compensation is introduced, based on the current change rate of the fuel cell. Correct in advance To cope with sudden loads.

[0088] Step 3: Obtain the pressure value P inside the gas cylinder. tank If the pressure value P tank >P th2 P th2 The second preset pressure threshold, and the increase in hydrogen storage per unit time. If the value is ≤k3, where k3 is a preset threshold, then the hydrogen recycling mode is entered, and the hydrogen in the storage cylinder is delivered to the fuel cell; otherwise, the hydrogen recycling and pressurization mode is maintained.

[0089] in In the formula, The molar mass of hydrogen gas is... The volume of the gas cylinder, The gas constant is... Real-time temperature of the gas storage cylinder. The rate of pressure change per unit time in the gas storage cylinder is used to calculate the increase in hydrogen storage per unit time. When the flow rate is ≤0.05g / s, the controller detects P. tank >P th2 , When the hydrogen concentration is simultaneously ≤0.05 g / s, the second gas path is disconnected, and the third gas path recirculates the unreacted hydrogen in the storage tank back to the fuel cell inlet, entering the hydrogen recycling mode. The third gas path is equipped with a one-way valve to prevent hydrogen backflow, and this one-way valve is linked to the third solenoid valve on the outlet side of the storage tank. This ensures that the recirculated hydrogen is activated only when the fuel cell requires additional hydrogen supply or when the storage tank meets the pressure requirement for hydrogen storage efficiency, avoiding the waste of hydrogen utilization caused by simply relying on the pressure threshold to trigger the circulation.

[0090] To optimize the mixing uniformity during the hydrogen circulation process, a static mixer is added to the third gas path, and the Reynolds number Re of hydrogen in the mixer is calculated to determine the flow state.

[0091]

[0092] In the formula: The density of hydrogen gas, For flow rate, The characteristic diameter of the mixer, Dynamic viscosity. When At that time, the eddy current generator in the static mixer is activated to increase the turbulence intensity through periodic disturbance, ensuring that the returned hydrogen is fully mixed with the fresh hydrogen and avoiding the impact of local concentration unevenness on the performance of the fuel cell stack.

[0093] To ensure smoother switching between different gas paths, a comprehensive judgment based on data from multiple sensors is required.

[0094] It also includes the following control processes:

[0095] Construct the judgment function F:

[0096]

[0097] In the formula: P1 is the hydrogen pressure in the high-pressure gas cylinder, T is the hydrogen temperature inside the high-pressure gas cylinder, and Q is the current hydrogen flow rate in the gas path. , , All are weighting coefficients;

[0098] like , If the preset threshold is met, the hydrogen circulation pressurization mode will be activated.

[0099] like , If the preset threshold is met, the direct hydrogen supply mode will be activated.

[0100] Pressure change rate judgment logic identifies pressure trend judgment function The system integrates multiple parameters, including pressure, temperature, and flow rate, to determine gas path switching and operating modes. This complements the aforementioned pressure change rate judgment logic, together forming the system's multivariable adaptive control strategy to ensure appropriate responses under various operating conditions.

[0101] Based on the linkage between the booster device in the second gas path and the third solenoid valve (i.e., the solenoid valve between the booster device and the gas cylinder), and combined with the target booster pressure value... Optimize the timing difference between the solenoid valve and the booster device. The original timing difference was a fixed value, which can be adjusted to a dynamic value:

[0102]

[0103] In the formula, For the real-time pressure of the gas storage cylinder, when and When the difference is large, Increase the time to 0.14 seconds, meaning the third solenoid valve opens for 0.14 seconds before the booster device starts, to avoid high-pressure impact on the air path; when the difference is small, Reduced to 0.1 seconds, shortening the boost response time and ensuring... Approaching rapidly Meanwhile, the closing logic of the fourth solenoid valve (i.e., the solenoid valve installed on the third gas line) needs to be synchronously linked to the energy efficiency coefficient. When the energy efficiency coefficient is too low and the energy consumption is too high, the fourth solenoid valve closes 0.05 seconds in advance to reduce hydrogen leakage during the ineffective pressurization stage.

[0104] A time compensation device is installed in the gas path between the high-pressure gas cylinder, the hydrogen storage tank, and the fuel cell. The response delay of the time compensation device is as follows:

[0105]

[0106] In the formula: In response to the delay time, This represents the change in pressure of gaseous hydrogen. This is a constant related to the response speed of the control valve.

[0107] By incorporating an event compensation device, the coordination of multi-stage control valves can be ensured, reducing the response caused by valve switching and ensuring the smoothness and accuracy of system switching. This method can adjust based on dynamic prediction of pressure changes. When the gas path switches, the valve opening and closing timing needs to be adjusted in advance based on the pressure prediction results. This method can predict the delay time during the switching process based on the amount of pressure change, thereby controlling the valve response time in advance, making valve switching and airflow regulation more precise.

[0108] The control system of this invention can dynamically adjust the connection status of each gas path and ensure that the booster device or hydrogen circulation can be activated in a timely manner when the pressure changes. Such adaptive control enables the hydrogen supply system to flexibly adjust its operating mode according to actual needs, improve the efficiency of hydrogen storage and supply, and avoid instability caused by excessive switching or response delays.

[0109] A real-time gas path health estimation module is also installed in the gas path between the high-pressure gas cylinder, hydrogen storage tank, and fuel cell, which estimates the health status using a state-space model.

[0110]

[0111] In the formula: This refers to the system status (such as the effective gas path diameter, valve response delay, etc.). For the input vector, For the observation vector, and All are observation noise, A is the state transition matrix, B is the input matrix, and H is the observation matrix; This represents the system state at the next moment.

[0112] The system state is estimated in real time using Kalman filtering; if the obtained gas path coefficient is lower than the threshold... If the gas path is blocked, the controller will switch to the backup gas path and trigger a maintenance alarm (the alarm module is built into the control system, and an alarm will be triggered if the condition is met).

[0113] Example 1

[0114] Taking a heavy-duty hydrogen fuel cell truck equipped with the control method of this invention driving at cruising power on a highway as an example, the process of adaptive adjustment based on operating conditions is illustrated.

[0115] A heavy-duty hydrogen fuel cell truck equipped with the system of this invention is cruising on a highway at its cruising power. At this time, the hydrogen consumption of the fuel cell is stable, and the gaseous hydrogen pressure in the high-pressure cylinder is... Maintain at 0.8 MPa, below the first preset pressure threshold. The pressure is set to 1.0 MPa, and hydrogen is supplied to the fuel cell in a direct hydrogen supply mode, that is, hydrogen is stably supplied to the fuel cell stack through the first gas path and the buffer tank.

[0116] The controller continuously monitors via pressure sensors According to the formula Calculate the rate of change of pressure, and then apply a weighted smoothing algorithm. Smoothing factor To filter out minute fluctuations, we use 0.7. The value is extremely small, the system determines that the operating condition is stable, and continues to use the direct hydrogen supply mode.

[0117] Subsequently, the truck entered a long downhill section, the driver released the ignition, and the fuel cell entered a low-power generation state, consuming hydrogen. The flow rate dropped sharply to 2 mol / s, far below the rated value. =5mol / s. This leads to a rapid pressure build-up inside the high-pressure cylinder, in... time, The pressure rose to 1.05 MPa, exceeding k1. Simultaneously, the controller calculated the smoothed pressure change rate. It also exceeded the set threshold. For example, 0.02. When both conditions are met simultaneously, the controller immediately determines that a mode switch is needed, and the hydrogen recirculation pressurization mode is triggered.

[0118] In hydrogen recirculation pressurization mode, the controller controls the solenoid valves on the corresponding gas lines to close the first gas line and open the second gas line. For precise control, a dynamic calculation model for the pressurization target value is activated, while the energy efficiency coefficient is monitored to maintain it within the optimal range, achieving a dynamic balance between hydrogen storage efficiency and energy consumption.

[0119] Based on the current low hydrogen consumption operating conditions =2mol / s, calculate the basic hydrogen supply pressure difference requirement. =0.2MPa. Combined with the required pressure at the fuel cell stack inlet. =0.5MPa and boost efficiency correction factor =0.95, calculate the target pressure. =0.69MPa, and the booster unit operates based on this target.

[0120] As pressurization proceeds, the pressure inside the gas cylinder... Gradually rising. When Exceeding the second preset pressure threshold For example, at 12 MPa, the controller did not immediately start the cycle, but instead further evaluated the hydrogen storage efficiency. The system then proceeded according to the formula... Calculate the increase in hydrogen storage per unit time. When the calculated... The hydrogen storage efficiency dropped to 0.04 g / s, which is below the threshold of 0.05 g / s, indicating a significant decrease and meeting the cycle triggering condition. The controller then opened the third gas path, returning the hydrogen from the storage tank to the fuel cell inlet.

[0121] When the truck leaves the ramp and needs to accelerate rapidly, the power demand of the fuel cell stack increases significantly. While the high-pressure cylinder supplies hydrogen through the main gas line, the recirculation gas line provides additional hydrogen. At this time, the pressure of the high-pressure cylinder... It began to decline due to increased consumption. The controller monitored this in real time. It is already lower than and A negative value indicates the crisis has passed, so the system shuts off the second and third gas lines and switches back to direct hydrogen supply mode. The multi-stage solenoid valves operate based on dynamic timing differences. Precise linkage was achieved to avoid high-pressure impacts, and the response was optimized through a delay compensation algorithm to ensure smooth and stable switching between various operating conditions.

[0122] Traditional methods often involve releasing pressure through a vent valve when the pressure in the high-pressure gas cylinder is too high, resulting in hydrogen waste. This invention addresses this by using a second gas path and a pressurization device to treat excess hydrogen as storable energy and transfer it to a storage cylinder. Instead of simple fixed-power pressurization, it dynamically calculates the required hydrogen supply pressure difference based on the real-time hydrogen consumption of the fuel cell, obtaining the most precise target pressure. This is further optimized through a closed-loop energy efficiency coefficient, ensuring the pressurization process operates within its optimal range. This avoids ineffective high-energy-consumption operation of the pressurization device, improving the overall energy efficiency of the system by both preventing waste and optimizing the process. By calculating and smoothing the pressure change rate to obtain a weighted pressure change rate, the controller can sensitively detect trending pressure changes, such as rapid pressure accumulation due to a sudden drop in fuel cell power, rather than simply responding to instantaneous pressure fluctuations. This allows the system to proactively activate the hydrogen circulation pressurization mode before the pressure actually exceeds the safety limit, actively managing the pressure and avoiding drastic pressure fluctuations. Simultaneously, when rapid vehicle acceleration causes a surge in hydrogen demand, the high-pressure hydrogen pre-stored in the storage tank can be immediately accessed via a third gas path, supplying hydrogen alongside the main gas path. This provides the system with a high-pressure, rapid energy buffer, ensuring instantaneous stability of the hydrogen supply pressure and meeting the stringent requirements of dynamic loads on the fuel cell. Furthermore, this invention implements multi-condition triggering logic for the hydrogen recycling mode and dynamic coordination of multi-stage control valves, and adds a hydrogen storage efficiency judgment condition, requiring an increase in hydrogen storage volume per unit time. From the formula Calculations show that the system only activates when the hydrogen flow rate falls below a threshold, such as 0.05 g / s. This ensures that the cycle mode is only activated when the storage tank is nearly full, efficiency decreases, and the fuel cell has a need for or can tolerate the flow, maximizing the utilization of stored hydrogen. Dynamic timing coordination between the valves and the pressurization device, along with a delay compensation algorithm, ensures smooth airflow during mode switching, preventing hydrogen leakage or pressure surges caused by improper valve opening and closing, thus guaranteeing the effective utilization of hydrogen.

Claims

1. A control method for an on-board hydrogen fuel cell hydrogen supply system based on adaptive operating conditions, characterized in that, Includes the following steps: Step 1: Obtain the pressure value P1 of the high-pressure gas cylinder. If the pressure value P1 ≤ P th1 P th1 If the first preset pressure threshold is met, then direct hydrogen supply mode is used to deliver hydrogen to the fuel cell; Otherwise, proceed to step 2; Step 2: If P1 > P th1 Simultaneously, the pressure change sequence P(t) of the high-pressure gas cylinder is detected to obtain the relative rate of change of pressure at time t. , judgment If the change threshold k1 is exceeded, the hydrogen circulation pressurization mode is entered, and hydrogen is introduced into the storage cylinder; otherwise, the direct hydrogen supply mode continues. Step 3: Obtain the pressure value P in the storage cylinder. tank If the pressure value P tank >P th2 P th2 The second preset pressure threshold, and the increase in hydrogen storage per unit time. If the value is ≤k3, where k3 is a preset threshold, then the hydrogen recycling mode is entered, and the hydrogen in the storage cylinder is delivered to the fuel cell; otherwise, the hydrogen recycling and pressurization mode is maintained.

2. The control method for an on-board hydrogen fuel cell hydrogen supply system based on adaptive operating conditions according to claim 1, characterized in that, In step 2, The weighted average is used to obtain the weighted rate of change of pressure. ; judgment Does it exceed the set threshold k2? If it meets the requirements at the same time... ＞k1， If the value is greater than k2, the system will enter the hydrogen circulation pressurization mode; otherwise, it will continue to operate in the direct hydrogen supply mode.

3. The control method for an on-board hydrogen fuel cell hydrogen supply system based on adaptive operating conditions according to claim 1, characterized in that, A pressurization device is installed in the gas line between the high-pressure gas cylinder and the gas storage cylinder; a dynamic calculation model for the newly added pressure target value is constructed, and the target pressure value is controlled by controlling the opening and closing of the pressurization device. In the formula: For the fuel cell stack inlet pressure requirements, For hydrogen supply pressure differential, The energy efficiency coefficient; under the hydrogen recirculation pressurization mode of the on-board hydrogen fuel cell hydrogen supply system, the energy efficiency coefficient is controlled. Within the preset range ,like If so, then shut off the booster device; like Then the booster device will be activated; where: In the formula: This refers to the energy consumption per unit time of the booster device.

4. The control method for an on-board hydrogen fuel cell hydrogen supply system based on adaptive operating conditions according to claim 1, characterized in that, In step 2, the pressure change sequence P(t) is decomposed into approximate components and detail components using wavelet basis functions; the energy entropy of the detail components is then calculated. ,like Less than the preset threshold If the pressure change sequence is not found to be noise, the calculation of the pressure change rate within the corresponding time period is ignored; otherwise, the relative change rate within that time period is calculated.

5. The control method for an on-board hydrogen fuel cell hydrogen supply system based on adaptive operating conditions according to claim 1, characterized in that, A pressurization device is installed in the gas line between the high-pressure gas cylinder and the gas storage cylinder; an optimization function for the pressurization device is constructed: In the formula: The output power of the booster device, The pressure P of the gas cylinder tank With target pressure The deviation is λ, where λ is the weighting coefficient and T is the prediction time domain; the start and stop of the booster device are controlled by this optimization function.

6. The control method for an on-board hydrogen fuel cell hydrogen supply system based on adaptive operating conditions according to claim 1, characterized in that, A static mixer is installed in the gas path between the gas storage cylinder and the fuel cell. The Reynolds number Re of hydrogen in the static mixer is calculated. If Re is less than a preset value, the eddy current generator built into the static mixer is activated; otherwise, the eddy current generator is turned off.

7. The control method for an on-board hydrogen fuel cell hydrogen supply system based on adaptive operating conditions according to claim 1, characterized in that, It also includes the following control process: Constructing the decision function F: In the formula: P1 is the hydrogen pressure in the high-pressure gas cylinder, T is the hydrogen temperature inside the high-pressure gas cylinder, and Q is the current hydrogen flow rate in the gas path. 、 、 All are weighting coefficients; if ， If the preset threshold is met, the hydrogen circulation pressurization mode will be activated. like ， If the preset threshold is met, the direct hydrogen supply mode will be activated.

8. The control method for an on-board hydrogen fuel cell hydrogen supply system based on adaptive operating conditions according to claim 3, characterized in that, A time compensation device is installed in the gas path between the high-pressure gas cylinder, the hydrogen storage tank, and the fuel cell. The response delay time of the time compensation device is as follows: In the formula: In response to the delay time, This represents the change in gaseous hydrogen pressure. It is a constant.

9. The control method for an on-board hydrogen fuel cell hydrogen supply system based on adaptive operating conditions according to claim 8, characterized in that, A real-time gas path health status estimation module is also installed in the gas path between the high-pressure gas cylinder, hydrogen storage tank, and fuel cell, which estimates the health status using a state-space model. In the formula: For system status, For the input vector, For the observation vector, and All are observation noise, A is the state transition matrix, B is the input matrix, and H is the observation matrix; The system state at the next moment; The system status is estimated in real time using Kalman filtering; if the obtained gas path coefficient is lower than the threshold, an alarm is triggered.

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