Boil-off gas treatment method of liquid hydrogen supply system and vehicle

Abstract

The invention relates to a boil-off gas treatment method of a liquid hydrogen supply system and a vehicle. The boil-off gas treatment method comprises the steps that the current working state of a fuel cell is obtained; predicting the boil-off gas pressure of the liquid hydrogen storage device in the preset future duration; and determining a target processing mode of the boil-off gas according to the boil-off gas pressure, the target preset pressure and the current working state of the fuel cell, and processing the boil-off gas according to the target processing mode. Therefore, the problems that the energy utilization efficiency of the whole vehicle is low, fuel is wasted and the like due to the fact that existing treatment of the boil-off gas of the vehicle-mounted liquid hydrogen storage tank cannot be managed in a self-adaptive mode according to the actual running state of the vehicle are solved, the pressure of the boil-off gas is pre-judged in advance, and the energy utilization rate of the vehicle is improved. By predicting the pressure of the boil-off gas and monitoring the working state of the fuel cell, a processing strategy can be started in time to control the boil-off gas in advance, the purposes of zero emission, low energy consumption and high safety of the vehicle-mounted liquid hydrogen system are achieved, and the overall performance and reliability of the vehicle-mounted liquid hydrogen system are improved.

Description

Technical Field

[0001] This application relates to the field of vehicle-mounted liquid hydrogen technology, and in particular to a method for treating evaporated gas in a liquid hydrogen supply system and a vehicle thereof. Background Technology

[0002] Due to limitations in thermal insulation, on-board liquid hydrogen storage devices inevitably absorb heat from the environment, causing some of the liquid hydrogen to vaporize and produce boil-off gas (BOG). Boiling-off gas can lead to increased tank pressure, threatening safety.

[0003] Existing evaporative gas handling strategies operate in a single mode, with each subsystem (liquid hydrogen system, fuel cell, and power battery) working independently. This makes it impossible to perform multi-mode adaptive management based on the actual operating status of the vehicle, resulting in low overall vehicle energy efficiency and fuel waste. This severely restricts the application and development of on-board liquid hydrogen systems in fuel cell vehicles. Summary of the Invention

[0004] This application provides a method and vehicle for treating the evaporated gas of a liquid hydrogen supply system, in order to solve the problem that the existing treatment of evaporated gas from on-board liquid hydrogen storage tanks cannot be adaptively managed according to the actual operating status of the vehicle, resulting in low energy utilization efficiency and fuel waste of the whole vehicle.

[0005] The first aspect of this application provides a method for treating evaporated gas in a liquid hydrogen supply system, comprising: acquiring the current operating state of a fuel cell; predicting the pressure of evaporated gas in a liquid hydrogen storage device within a preset future time period; determining a target treatment mode for the evaporated gas based on the evaporated gas pressure, a target preset pressure, and the current operating state of the fuel cell; and treating the evaporated gas according to the target treatment mode.

[0006] Optionally, predicting the evaporation gas pressure of the liquid hydrogen storage device within a preset future time period includes: obtaining the current internal temperature and the current external wall ambient temperature of the liquid hydrogen storage device; calculating the current heat transfer rate of the evaporation gas of the liquid hydrogen storage device based on the current internal temperature and the current external wall ambient temperature; calculating the vaporization amount of the evaporation gas within the preset future time period based on the current heat transfer rate; and calculating the evaporation gas pressure of the liquid hydrogen storage device within the preset future time period based on the vaporization amount of the evaporation gas within the preset future time period.

[0007] Optionally, determining the target processing mode for the evaporated gas based on the evaporated gas pressure, the target preset pressure, and the current operating state of the fuel cell, wherein the target preset pressure includes a first preset pressure and a second preset pressure, includes: if the evaporated gas pressure is less than the second preset pressure and the fuel cell is in operation, then the target processing mode is a supply processing mode; if the evaporated gas pressure is greater than or equal to the second preset pressure and less than the first preset pressure, then the target processing mode is a buffer processing mode; if the evaporated gas pressure is greater than or equal to the first preset pressure, then the target processing mode is an emission processing mode, wherein the second preset pressure is less than the first preset pressure.

[0008] Optionally, when processing the evaporated gas according to the supply processing mode, the method includes: determining the energy of the evaporated gas and obtaining the current power demand and available power margin of the fuel cell; if the energy of the evaporated gas is greater than the current power demand, calculating the power that can be increased in the fuel cell; comparing the power that can be increased in the fuel cell with the available power margin of the fuel cell, and processing the evaporated gas based on the comparison result of the power that can be increased in the fuel cell and the available power margin of the fuel cell.

[0009] Optionally, processing the evaporated gas based on a comparison between the power of the boostable fuel cell and the available power margin of the fuel cell includes: if the power of the boostable fuel cell is less than or equal to the available power margin of the fuel cell, then controlling a portion of the evaporated gas to be introduced into the fuel cell based on the power of the boostable fuel cell.

[0010] Optionally, if the power of the fuel cell that can be increased is greater than the available power margin of the fuel cell, the method includes: introducing a portion of the evaporated gas into the fuel cell according to the real-time power demand of the fuel cell, and discharging the excess evaporated gas to a second buffer device, wherein the gas in the second buffer device can be introduced into the fuel cell.

[0011] Optionally, if the energy of the evaporated gas is less than or equal to the current power requirement, the method includes: controlling the evaporated gas to be introduced into the fuel cell.

[0012] Optionally, processing the evaporated gas according to the buffer processing mode includes: controlling the first pressure relief device to open and passing the evaporated gas into the second buffer device for buffering.

[0013] Optionally, the evaporated gas is treated according to the emission treatment mode, including: controlling the second pressure relief device to open, releasing hydrogen in the second buffer device to the catalytic device, where it undergoes a chemical reaction and is then discharged into the atmosphere.

[0014] A second aspect of this application provides a vehicle comprising: a memory, a processor, and a computer program stored in the memory and capable of running on the processor, wherein the processor executes the program to implement the evaporation gas treatment method of the liquid hydrogen supply system as described in the above embodiments.

[0015] In the above embodiments, the current operating state of the fuel cell is obtained; the pressure of the evaporated gas in the liquid hydrogen storage device within a preset future time period is predicted; a target processing mode for the evaporated gas is determined based on the evaporated gas pressure, the target preset pressure, and the current operating state of the fuel cell; and the evaporated gas is processed according to the target processing mode. This solves the problem that existing methods for handling evaporated gas from on-board liquid hydrogen storage tanks cannot adaptively manage the gas according to the actual operating state of the vehicle, leading to low overall vehicle energy efficiency and fuel waste. It achieves advance prediction of evaporated gas pressure; by predicting the evaporated gas pressure and monitoring the fuel cell's operating state, processing strategies can be activated in a timely manner to control the evaporated gas in advance, achieving the goals of zero emissions, low energy consumption, and high safety for the on-board liquid hydrogen system, significantly improving the overall performance and reliability of the on-board liquid hydrogen system in fuel cell vehicles.

[0016] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0017] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1 A schematic diagram illustrating the installation layout and working principle of a liquid hydrogen supply system for heavy-duty trucks in related technologies. Figure 2 This is a flowchart of an evaporation gas treatment method for a liquid hydrogen supply system according to an embodiment of this application; Figure 3 This is a schematic diagram of the structure of an on-board liquid hydrogen supply system according to a specific embodiment of this application; Figure 4 This is a schematic diagram of the control network topology and connection of an on-board hydrogen system according to an embodiment of this application; Figure 5 This is a flowchart illustrating the data acquisition process of a novel on-board liquid hydrogen supply system according to an embodiment of this application. Figure 6 This is a flowchart of a multi-mode control method for evaporating hydrogen in a novel on-board liquid hydrogen supply system according to an embodiment of this application; Figure 7 This is a schematic diagram of a vehicle structure according to an embodiment of this application. Detailed Implementation

[0018] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0019] To address the issues mentioned in the background section regarding the inability of existing on-board liquid hydrogen storage tanks to adaptively manage evaporated gas based on the vehicle's actual operating status, leading to low overall vehicle energy efficiency and fuel waste, this application provides a method for handling evaporated gas in a liquid hydrogen supply system. This method involves acquiring the current operating status of the fuel cell; predicting the evaporated gas pressure of the liquid hydrogen storage device within a preset future timeframe; determining a target processing mode for the evaporated gas based on the evaporated gas pressure, a target preset pressure, and the current operating status of the fuel cell; and processing the evaporated gas according to the target processing mode. This solves the problem of existing on-board liquid hydrogen storage tank evaporation gas handling methods failing to adaptively manage based on the vehicle's actual operating status, resulting in low overall vehicle energy efficiency and fuel waste. It enables advance prediction of evaporated gas pressure, and through prediction of evaporated gas pressure and monitoring of the fuel cell's operating status, timely activation of processing strategies and advance control of the evaporated gas can achieve the goals of zero emissions, low energy consumption, and high safety for on-board liquid hydrogen systems, significantly improving the overall performance and reliability of on-board liquid hydrogen systems in fuel cell vehicles.

[0020] As a crucial component for storing hydrogen required for the operation of fuel cells or hydrogen internal combustion engines, on-board hydrogen systems can provide a stable supply of hydrogen according to the operating pressure and flow requirements of these systems. Currently, on-board hydrogen supply systems mainly consist of high-pressure gaseous hydrogen storage and cryogenic liquid hydrogen storage. Compared to high-pressure gaseous hydrogen storage, the core advantage of on-board liquid hydrogen systems lies in their extremely high energy density. After hydrogen is liquefied at -253°C, its volume is only about 1 / 845th of its gaseous state. This allows for the storage of far more hydrogen in the same volume of hydrogen storage tank compared to high-pressure gaseous hydrogen, resulting in longer driving ranges for vehicles and significantly reducing the weight of the hydrogen storage system. This is an important technological path for enabling long-distance operation of commercial vehicles such as heavy trucks and buses.

[0021] like Figure 1As shown in Figure (a), the core of the onboard liquid hydrogen system is a double-walled vacuum-insulated storage tank, resembling a "super thermos." The interlayer is evacuated to a high vacuum and covered with highly efficient insulating material to maximize heat transfer and maintain the liquid hydrogen in a cryogenic liquid state. During operation, liquid hydrogen flows out from the bottom of the tank, absorbing heat from the environment and the engine coolant, rapidly vaporizing into room-temperature gaseous hydrogen, which is stored in a buffer tank. The pressure is then stabilized and reduced to the working pressure required by the fuel cell by a pressure regulating valve before being supplied to the power system. However, absolute insulation is currently impossible to achieve. Heat seeping into the liquid hydrogen tank causes a small amount of liquid hydrogen to continuously evaporate (called "boiling evaporation"), causing the pressure inside the tank to rise slowly. If the pressure of the evaporated gaseous hydrogen continues to rise to a set threshold, the safety relief valve will automatically open to release excess hydrogen. In the event of a malfunction causing a sudden and abnormal pressure, the safety relief valve will act as a final emergency pressure relief, releasing the hydrogen from the liquid hydrogen vent pipe. Figure 1 As shown in Figure (b), the onboard liquid hydrogen system is ensured to operate normally under any conditions.

[0022] However, the aforementioned method of handling evaporated gases involves directly releasing hydrogen into the atmosphere through a pressure relief valve, resulting in a fuel loss rate of 3%-6% per day. This wastes energy, poses an explosion hazard in confined spaces (such as garages), and lacks the ability to perform multi-mode adaptive management based on the vehicle's actual operating conditions. This leads to low overall vehicle energy efficiency and fuel waste, severely hindering the application and development of onboard liquid hydrogen systems in fuel cell vehicles. To address the aforementioned problems, this application provides a method for treating evaporated gas in a liquid hydrogen supply system. Specifically, Figure 2 This is a schematic flowchart illustrating an evaporation gas treatment method for a liquid hydrogen supply system provided in an embodiment of this application.

[0023] It should be noted that the liquid hydrogen supply system in this application is based on the original technical solution (i.e., in... Figure 1 Based on the structure of (b), add corresponding components and the functions of related components, such as Figure 3 As shown: (1) Add a second buffer tank (i.e., a second buffer device): When the pressure of the evaporated gas in the liquid hydrogen storage tank (i.e., the liquid hydrogen storage device) reaches the second preset pressure (exemplarily 1.15 MPa), the first safety relief valve opens, allowing the evaporated gas to enter the second buffer tank, reducing hydrogen waste; (2) Add a first safety pressure relief valve (i.e., a first pressure relief device): it opens when the evaporating gas pressure is greater than the second preset pressure (i.e., the evaporating gas pressure is greater than 1.15MPa), and closes under other conditions; (3) Add a one-way valve: Hydrogen in the second buffer tank enters the water vaporizer through the pipeline, is heated, and then enters the first buffer tank for engine use, preventing hydrogen backflow; (4) Add a water vaporizer: heat the hydrogen that enters the first buffer tank through the second buffer tank, and heat the gas output from the air vaporizer, and deliver it to the engine through the pressure regulating valve to ensure the normal gas supply of the engine. (5) Second safety relief valve (i.e., second pressure relief device): When the pressure inside the second buffer tank is greater than the first preset pressure (exemplarily 1.2MPa), that is, when the evaporation gas pressure is greater than 1.2MPa, the second safety relief valve is opened to discharge into the catalytic device 800; (6) Pressure sensor: Installed inside the liquid hydrogen storage tank and on the pipeline respectively, a high-precision and high-reliability pressure sensor is selected to measure the internal pressure P_tank of the storage tank. The measurement accuracy can reach ±0.1%FS (full scale) and can accurately reflect the pressure change of the storage tank in real time. (7) Temperature sensor: A platinum resistance temperature sensor or a thermocouple sensor is used to measure the internal temperature T_tank and the ambient temperature T_ambient of the storage tank, respectively, with an accuracy of ±0.5℃, to ensure accurate monitoring of temperature parameters; (8) Liquid level sensor: An ultrasonic liquid level sensor or a capacitive liquid level sensor is used to accurately measure the liquid level L_level in the storage tank with an accuracy of ±1mm, providing accurate liquid level information for the system; (9) Catalytic hydrogen elimination device (i.e., catalytic device): The hydrogen gas discharged from the hydrogen exhaust pipeline reacts with the tail gas of the catalytic hydrogen elimination device. The main products are water vapor (H2O) and a small amount of unreacted inert gas (such as nitrogen), so as to achieve safe hydrogen-free emission of the hydrogen system.

[0024] Specifically, in step S201, the current operating state of the fuel cell is obtained.

[0025] The control network topology and connections of the on-board liquid hydrogen supply system are as follows: Figure 4 As shown, the data acquisition process of the on-board liquid hydrogen supply system is as follows: Figure 5 As shown.

[0026] Figure 4 In this system, the HMS controller is the onboard liquid hydrogen system controller. Based on data collected from temperature, pressure, and level sensors, it monitors changes in pressure, temperature, and liquid level in real time, predicting the evaporation gas pressure of the liquid hydrogen storage device over a future period. The FCU controller is the fuel cell controller, monitoring the fuel cell's current power demand P_fc_request and available power margin P_fc_margin in real time. The Vehicle Control Unit (VCU) utilizes the vehicle's existing sensor system to acquire information on the vehicle's driving status (driving / stationary / charging status), ensuring accurate judgment of the vehicle's condition. The Battery Management System (BMS) monitors the battery's State of Charge (SOC) value in real time.

[0027] Figure 5 In this system, subtle changes in the internal pressure of the storage tank are monitored, the temperature of the liquid hydrogen (T_tank) is measured, the ambient temperature (T_ambient) on the outer surface of the tank is acquired, and the liquid hydrogen level (L_level) inside the tank is monitored. The raw data collected by the sensors are preprocessed, and each sensor's data is calibrated according to its specific calibration curve or algorithm. Taking the pressure sensor as an example, the measured value is linearly corrected according to its calibration equation P_corrected = 1.002P_measured + 0.01 to ensure high accuracy and reliability of the data.

[0028] The fuel cell controller (FCU) monitors the current power demand (P_fc_request) and available power margin (P_fc_margin) of the fuel cell in real time. In addition, the vehicle controller (VCU) communicates with the vehicle's CAN bus in real time to obtain real-time vehicle status information (such as driving, stationary, and charging status), and the battery management system (BMS) monitors the state of charge (SOC) value of the power battery in real time.

[0029] It should be noted that the available power margin is the difference between the total output power of the fuel cell and the current power demand. For example, if the total output power of the fuel cell is 70 kW and the current power demand is 50 kW, the available power margin P_fc_margin is 20 kW.

[0030] In step S202, the pressure of the evaporated gas in the liquid hydrogen storage device within a preset future time period is predicted.

[0031] Optionally, in some embodiments, predicting the evaporation gas pressure of the liquid hydrogen storage device within a preset future time period includes: obtaining the current internal temperature and the current external ambient temperature of the liquid hydrogen storage device; calculating the current heat transfer rate of the evaporation gas of the liquid hydrogen storage device based on the current internal temperature and the current external ambient temperature; calculating the vaporization amount of the evaporation gas within the preset future time period based on the current heat transfer rate; and calculating the evaporation gas pressure of the liquid hydrogen storage device within the preset future time period based on the vaporization amount of the evaporation gas within the preset future time period.

[0032] Specifically, based on the collected data, the vaporized gas pressure P_predict and the vaporized gas BOG generation rate R_bog are predicted using a thermodynamic model over a future period of time △t (e.g., set to 15 minutes).

[0033] Specifically, the steps for predicting the vaporized gas pressure P_predict and the BOG generation rate R_bog in the storage tank are as follows: First, a thermodynamic model is constructed: Based on fundamental thermodynamic principles, and fully considering the double-layer vacuum insulation structure of the onboard liquid hydrogen storage tank and various heat transfer mechanisms during actual operation, a thermodynamic model is constructed. For heat transfer calculations, radiative heat transfer is precisely calculated according to the Stefan-Boltzmann law Q_rad=σ·ε·A(T_ambient^4-T_tank^4), where the Stefan-Boltzmann constant σ=5.67×10^-8W / (m²·K). 4 The surface emissivity of the storage tank is ε=0.05, and the surface area is A. Simultaneously, considering the conductive heat transfer of the residual gas inside the tank, the conductive heat transfer rate Q_cond of the residual gas is accurately calculated based on the gas thermal conductivity formula and factors such as the tank's geometry and temperature distribution.

[0034] Combining radiative and conductive heat transfer, the current heat transfer rate is obtained as Q = Q_rad + Q_cond. Based on the current heat transfer rate, the latent heat of vaporization of liquid hydrogen L = 445 kJ / kg, and the time interval Δt (set to 15 minutes), the amount of liquid hydrogen vaporized m within Δt is accurately calculated using the formula m = Q × Δt / L.

[0035] Further state prediction based on the van der Waals equation: The van der Waals equation (P + n²a / V²)(V - nb) = nRT is used to describe the actual state of hydrogen in the storage tank, where a = 0.244 Pa·m 6 Where b = 2.661 × 10⁻⁵ m³ / mol is the van der Waals constant for hydrogen, V is the tank volume (assumed to be 8 m³), ​​n is the amount of gaseous substance, R = 8.314 J / (mol·K) is the ideal gas constant, and T is the temperature (in K). Based on the calculated vaporization amount, the amount of hydrogen Δn and related parameters are accurately updated. By iteratively solving the van der Waals equation, the pressure change trend of the tank in the next 15 minutes is predicted, thus obtaining a highly accurate vaporized gas pressure P_predict and the BOG formation rate R_bog.

[0036] The above technical solution, based on the current state data of the liquid hydrogen storage device, calculates the heat transfer rate of the evaporating gas using a thermodynamic model. Based on the heat transfer rate and the latent heat of vaporization of liquid hydrogen, it calculates the amount of vaporized gas to be generated in the future. This allows the system to accurately determine the BOG generation rate over a future period. The use of the van der Waals equation to predict tank pressure improves the accuracy of tank pressure prediction and avoids inaccurate control of the evaporating gas caused by relying solely on fixed pressure values. Furthermore, based on the predicted evaporating gas pressure, the system can proactively activate appropriate processing modes to reduce pressure and prevent potential safety hazards caused by overpressure.

[0037] In step S203, the target processing mode of the evaporated gas is determined based on the evaporated gas pressure, the target preset pressure and the current operating state of the fuel cell, and the evaporated gas is processed according to the target processing mode.

[0038] Optionally, in some embodiments, a target processing mode for the evaporated gas is determined based on the evaporated gas pressure, a target preset pressure, and the current operating state of the fuel cell. The target preset pressure includes a first preset pressure and a second preset pressure, including: if the evaporated gas pressure is less than the second preset pressure and the fuel cell is in operation, the target processing mode is a supply processing mode; if the evaporated gas pressure is greater than or equal to the second preset pressure and less than the first preset pressure, the target processing mode is a buffer processing mode; if the evaporated gas pressure is greater than or equal to the first preset pressure, the target processing mode is an emission processing mode, wherein the second preset pressure is less than the first preset pressure.

[0039] The first preset pressure and the second preset pressure can be thresholds preset by the user, thresholds obtained through a limited number of experiments, or thresholds obtained through a limited number of computer simulations. For ease of explanation, in this embodiment, the first preset pressure P_vent is 1.2 MPa and the second preset pressure P_warning is 1.15 MPa.

[0040] It is understandable that when the evaporating gas pressure P_predict is less than P_warning and the fuel cell is in operation, the evaporating gas is processed by the supply processing mode. When the evaporating gas pressure P_predict is greater than or equal to P_warning and less than the first preset pressure P_vent, the evaporating gas is processed using a buffer processing mode. When the pressure of the evaporated gas is greater than or equal to the first preset pressure, the evaporated gas is treated by the emission treatment mode.

[0041] Through the above technical solution, the system dynamically switches between supply processing mode, buffer processing mode and emission processing mode based on the predicted evaporation gas pressure, two preset pressure thresholds and the current operating status of the fuel cell. This makes the BOG processing strategy not a single emission or recovery, greatly improving the system's flexibility and adaptability.

[0042] Optionally, in some embodiments, when processing the evaporated gas according to the supply processing mode, the process includes: determining the energy of the evaporated gas and obtaining the current power demand and available power margin of the fuel cell; calculating the power that can be increased for the fuel cell when the energy of the evaporated gas is greater than the current power demand; comparing the power that can be increased for the fuel cell with the available power margin of the fuel cell, and processing the evaporated gas based on the comparison result of the power that can be increased for the fuel cell and the available power margin of the fuel cell.

[0043] It should be noted that the increased fuel cell power △P_fc refers to the total power E_bog provided by BOG × / △t - Current power demand P_fc_demand of the fuel cell, representing the excess △P_fc available to the fuel cell beyond what the BOG can satisfy. The efficiency of electrical energy is denoted by Δt, which is a preset time interval.

[0044] The method for determining the energy of the evaporated gas is as follows: The flow rate of the evaporated gas supplied to the fuel cell is calculated based on the evaporated gas pressure P_predict and the evaporation gas generation rate: dot{V}_bog=dot{n}*R*T_tank / P_tank; (1) dot{n}_bog=R_bog / M_H2; (2) Where dot{V}_bog is the flow rate of the evaporated gas, dot{n}_bog is the molar flow rate, R is the ideal gas constant, n is the amount of substance, V is the volume, P_tank is the current pressure of the liquid hydrogen storage tank, T_tank is the current internal temperature of the liquid hydrogen storage tank, R_bog is the generation rate of the evaporated gas, and M_H2 is the molar mass of hydrogen.

[0045] Assuming BOG is considered an ideal gas, according to the ideal gas law PV=nRT (where P is pressure, V is volume, n is amount of substance, R is ideal gas constant, and T is temperature), we can first calculate the amount of BOG produced per unit time dot{n}_bog under the current tank pressure P_tank and temperature T_tank.

[0046] Given that the BOG formation rate R_bog is expressed as mass flow rate (unit: kg / min), and the molar mass of hydrogen M_H2 = 2 × 10^-3 kg / mol, then the mass flow rate dot{n}_bog = R_bog / M_H2.

[0047] According to the ideal gas law, the volumetric flow rate of BOG can be obtained as: dot{V}_bog=dot{n}_bog*RT_tank / P_tank. This volumetric flow rate dot{V}_bog is the BOG flow rate currently available to the fuel cell, and further, the BOG flow rate is converted into the corresponding energy of the evaporated gas E_bog.

[0048] Optionally, in some embodiments, the evaporating gas is processed based on a comparison between the power that can be increased in the fuel cell and the available power margin of the fuel cell, including: if the power that can be increased in the fuel cell is less than or equal to the available power margin of the fuel cell, then controlling a portion of the evaporating gas to be introduced into the fuel cell based on the power that can be increased in the fuel cell.

[0049] The control method flow of the on-board liquid hydrogen supply system is as follows: Figure 6 As shown.

[0050] The specific processing method of the priority supply processing model is as follows: When the evaporating gas pressure P_predict is less than the second preset pressure P_warning, and the fuel cell is in operation, the system prioritizes introducing all BOG (Boiler Gas) into the fuel cell. During this process, the system monitors the real-time power demand of the fuel cell P_fc_demand and compares it with the energy of the evaporating gas. If the energy of the evaporating gas is greater than P_fc_demand, the system will further calculate the power increase ΔP_fc that can be achieved in the fuel cell.

[0051] If the power that can be increased in the fuel cell is less than or equal to the available power margin of the fuel cell, then based on the power that can be increased in the fuel cell, a portion of the evaporated gas is introduced into the fuel cell to increase the output power of the fuel cell.

[0052] When the SOC of the power battery is less than or equal to the preset value (e.g., 80%), the energy of the remaining gas in the evaporated gas is reasonably allocated to the power battery for charging. The SOC of the battery is controlled by the BMS to achieve optimized energy utilization. When the SOC of the power battery is greater than the preset value (e.g., 80%), the power battery will no longer be charged. At this time, the excess BOG will be stored in the first buffer tank.

[0053] The specific supply processing model is as follows: Step 1. Obtain the real-time power requirement of the fuel cell: The fuel cell control unit (FCU) obtains the actual power required by the fuel cell in real time. This value reflects the energy input required by the fuel cell at that moment to meet the power demand of the vehicle operation or the power battery.

[0054] Step 2. Calculate BOG flow rate: Calculate the BOG flow rate currently available for supplying the fuel cell by combining the BOG generation rate R_bog with the current pressure, temperature, and other conditions of the storage tank. Since the main component of BOG is hydrogen, the calculation can be performed using the ideal gas law (or such as the van der Waals equation) and the relationship between mass flow rate and mass flow rate.

[0055] Step 3. Determine the relationship between BOG energy and fuel cell energy demand. Convert the BOG flow rate into the corresponding energy and compare the energy of the evaporated gas with the real-time power demand P_fc_demand of the fuel cell. Given the calorific value of hydrogen q_H2 (approximately 142 MJ / kg), the energy contained in the BOG per unit time is E_bog = R_bog × q_H2.

[0056] Determine whether the energy of the evaporated gas is greater than the real-time power demand P_fc_demand.

[0057] Step 4. Calculate the increase in fuel cell power ΔP_fc If the energy contained in the evaporated gas, E_bog, is greater than the real-time power demand, P_fc_demand, calculate the power increase value △P_fc of the fuel cell.

[0058] Step 5. Determine the power margin Determine whether the power value that can be increased in the fuel cell, ΔP_fc, is true if P_fc_margin is less than or equal to P_fc_margin.

[0059] If ΔP_fc≤P_fc_margin holds: By increasing the fuel supply to the fuel cell through the power regulation system (i.e., increasing the BOG input), the output power is increased by ΔP_fc. When the power battery's charge value is less than or equal to 80%, the energy of the excess evaporated gas is used to charge the power battery. When the power battery's SOC is greater than 80%, the power battery will no longer be charged.

[0060] Through the above technical solution, when the power that can be increased to the fuel cell is less than or equal to the available power margin of the fuel cell, the real-time demand and power margin of the fuel cell, as well as the state of charge of the power battery, are fully considered. This avoids the fuel cell being forced to increase its power when no additional power is needed, reducing unnecessary load fluctuations. When the output power of the fuel cell can be increased, the evaporated gas is introduced into the fuel cell to increase its output power. When the battery's power charge is below a preset value, part of the energy of the evaporated gas is transferred to the power battery for charging, maximizing the recovery of the energy of the evaporated gas and significantly improving the energy utilization efficiency of the entire vehicle. When the power battery's state of charge (SOC) reaches its upper limit, the energy of the remaining evaporated gas is stored, reducing resource waste.

[0061] Optionally, in some embodiments, when the power of the fuel cell can be increased to a level greater than the available power margin of the fuel cell, the method includes: introducing a portion of the evaporated gas into the fuel cell according to the real-time power demand of the fuel cell, and discharging the excess evaporated gas to a second buffer device, wherein the gas in the second buffer device can be introduced into the fuel cell.

[0062] Specifically, when the power that can be increased in the fuel cell exceeds the fuel cell's available power margin, a command is sent to introduce a portion of the evaporated gas into the fuel cell at a flow rate of P_fc_demand. At this point, since the fuel cell cannot utilize all the excess BOG (Boiler Gas Registry), the excess evaporated gas needs to be temporarily stored. This can be done in a second buffer tank to prevent excessive pressure in the storage tank. The gas in the second buffer tank can be heated by a water vaporizer via an electromagnetic switch valve and a check valve before entering the first buffer tank for use by the fuel cell.

[0063] Through the above technical solution, when the power that can be increased is greater than the available power margin of the fuel cell, the system does not forcibly introduce all BOG into the fuel cell. Instead, it stores the excess BOG in the second buffer device, creating conditions for its subsequent utilization, thereby maximizing energy recovery. The BOG stored in the second buffer device is not idle, but can be reintroduced into the first buffer device through a one-way valve and a water vaporizer for subsequent gas supply, which can effectively reduce the pressure on the second buffer device.

[0064] Optionally, in some embodiments, when the energy of the evaporated gas is less than or equal to the current power requirement, the method includes controlling the flow of the evaporated gas into the fuel cell.

[0065] If the energy of the evaporated gas E_bog is less than or equal to the real-time power demand P_fc_demand, it means that the energy provided by BOG is just enough or insufficient to meet the fuel cell demand. At this time, a command is sent to import all the evaporated gas into the first buffer device and release the gas in the first buffer device into the fuel cell to meet the power demand of the fuel cell and ensure the normal operation of the fuel cell.

[0066] Through the above series of calculation and control steps, under the priority supply and processing strategy, the system can rationally allocate BOG energy according to the real-time demand of the fuel cell and the BOG generation, thereby achieving efficient energy utilization.

[0067] Through the above technical solution, when the BOG energy is insufficient to meet the current demand of the fuel cell, the system supplies all BOG to the fuel cell, ensuring that the fuel cell can obtain the minimum fuel supply required to maintain its normal power generation state and maximize energy utilization efficiency.

[0068] Optionally, in some embodiments, the evaporating gas is processed according to a buffer processing mode, including: controlling the first pressure relief device to open and passing the evaporating gas into a second buffer device for buffering.

[0069] Specifically, the buffer processing mode works as follows: when the evaporating gas pressure P_predict ≥ the second preset pressure P_warning and the evaporating gas pressure P_predict < the first preset pressure P_vent, the first pressure relief device of the on-board liquid hydrogen supply system is opened, and the evaporating gas enters the second buffer device for storage, reducing the waste caused by venting into the atmosphere.

[0070] When the fuel cell is put back into operation, the evaporated gas is processed using a supply processing mode, prioritizing the use of evaporated gas from the liquid hydrogen storage tank and the second buffer device. The calculation and control steps are the same as those described above for the supply processing mode.

[0071] Through the above technical solution, when the fuel cell is not working and cannot consume BOG, the system actively introduces BOG into the second buffer device when the tank pressure reaches the warning value. This can effectively reduce the pressure in the liquid hydrogen tank and allow it to be used when the fuel cell is restarted or the system needs it, thus avoiding the waste of hydrogen energy and improving the energy economy of the whole vehicle.

[0072] Optionally, in some embodiments, the evaporated gas is treated according to the emission treatment mode, including: controlling the second pressure relief device to open, releasing hydrogen in the second buffer device to the catalytic device, where it undergoes a chemical reaction and is then emitted into the atmosphere.

[0073] Specifically, when the vapor pressure P_predict approaches the first preset pressure P_vent (i.e., P_predict ≥ P_vent), the system will activate the safe emission mode. At this time, the controllable second pressure relief device in the on-board liquid hydrogen supply system will quickly open to release the excessive pressure in the second buffer device. The released hydrogen is precisely guided into the on-board catalytic hydrogen elimination device, where it is converted into water through a catalytic reaction and safely released into the atmosphere, minimizing the environmental impact.

[0074] When the fuel cell is put back into operation, the evaporated gas is processed using a supply processing mode, prioritizing the use of evaporated gas from the liquid hydrogen storage tank and the second buffer device. The calculation and control steps are the same as those described above for the supply processing mode.

[0075] With the above technical solution, when the pressure of the evaporated gas approaches or reaches the first preset pressure, the system starts the emission treatment mode. The emitted hydrogen is not directly released into the atmosphere, but is introduced into the on-board catalytic hydrogen removal device, where it is converted into water through a catalytic reaction, eliminating the explosion safety hazard of direct emission. The remaining gas in the second buffer device can be used when the fuel cell is restarted or when the system needs it, avoiding the waste of hydrogen energy and improving the energy economy of the whole vehicle.

[0076] Taking a long-haul liquid hydrogen heavy-duty truck as an example, the liquid hydrogen storage tank of the on-board liquid hydrogen system has a volume of 500L. Step 1: Real-time Data Acquisition 1. Sensor data acquisition Pressure sensors: The top pressure sensor measured P_tank-top=0.92MPa, and the bottom pressure sensor measured P_tank-bottom=0.91MPa. The average tank pressure was calculated to be P_tank=(0.92+0.91) / 2=0.915MPa.

[0077] Temperature sensors: Three internal temperature sensors measured T_tank1 = -252.3℃, T_tank2 = -252.1℃, and T_tank3 = -252.2℃ respectively. The average liquid hydrogen temperature T_tank = (-252.3 - 252.1 - 252.2) / 3 = -252.2℃. The ambient temperature sensor detected T_ambient = 35℃.

[0078] Liquid level sensor: The capacitive liquid level sensor shows that the liquid level in the storage tank is L_level=60%, indicating that the liquid hydrogen storage in the storage tank is 60%.

[0079] FCU: The calculated current power demand of the fuel cell is P_fc_request = 50kW, and the known available power margin of the fuel cell is P_fc_margin = 20kW.

[0080] Vehicle status sensor: Indicates that the vehicle is in operation.

[0081] BMS: Battery SOC is 70%.

[0082] 2. Data Preprocessing The collected data is calibrated according to the calibration curves of each sensor. For example, for the pressure sensor, according to the calibration equation P_corrected = 1.002P_measured + 0.01, the calibrated pressure P_tank - corrected = 1.002 × 0.915 + 0.01 = 0.92683 MPa. Other sensor data are also corrected according to the corresponding calibration methods and stored in a temporary buffer.

[0083] Step 2: Pressure Trend Forecast 1. Thermodynamic model calculation Read the calibrated data from the temporary buffer and input it into the thermodynamic model. Calculate the radiative heat transfer rate Q_rad, where the Stefan-Boltzmann constant σ = 5.67 × 10⁻⁶. -8 W / (m²·K 4 The surface emissivity of the storage tank is ε=0.05, and the surface area A needs to be recalculated based on the new storage tank volume.

[0084] Assuming the storage tank is cylindrical, according to V=pir 2 h≈0.5m³, assuming the height-to-diameter ratio h / r=3, i.e., h=3r, then pir 2 (3r)≈0.5, solving this equation yields... h = 3r ≈ 1.1m.

[0085] The inner surface area of ​​a cylinder is: A = 2pirh + 2pir 2 =2pi*0.37*(1.1+0.37)≈2.7m².

[0086] T_ambient = 35 + 273.15K = 308.15K, T_tank = -252.2 + 273.15K = 20.95K. According to the formula Q_rad = σ * ε * A(T_ambient) 4 -T_tank 4 The calculated value is Q_rad = 5.67 × 10⁻⁶. -8 W / (m²·K 4 )×0.05×2.7m²×(308.15 4 K-20.954 4 K)≈68.8W.

[0087] Further calculations were performed on the residual gas conduction heat transfer rate Qcond to determine relevant parameters: Gas thermal conductivity k: Assuming the thermal conductivity of hydrogen in its current state.

[0088] Heat transfer area A: A≈2.7m² has been calculated.

[0089] Temperature gradient dT / dx: Assuming the temperature change mainly occurs within the gas layer near the inner wall with a thickness of Δx = 0.05 m, the temperature gradient is: ; Substituting the parameters into the formula Q_cond=-kAdT / dx, and taking the absolute value, we get Q_cond=0.18W / (m*K)×2.7m²×5744K / m / 1000≈2.8W.

[0090] Total heat transfer rate: Q = Q_rad + Q_cond = 68.8 + 2.8 = 71.6 W.

[0091] Latent heat of vaporization of liquid hydrogen: L = 445 kJ / kg, set time: Δt = 15 × 60 s = 900 s, calculate the vaporization amount of liquid hydrogen: m = Q × Δt / L = (71.6 W × 900 s) / (445 kJ / kg × 1000) ≈ 0.144 kg.

[0092] Update the amount of hydrogen substance Δn according to the vaporization amount, substitute it into the van der Waals equation (P + n²a / V²)(V - nb) = nRT, where (a = 0.244 Pa·m 6 / mol², b = 2.661 × 10 -5 m³ / mol, V = 0.5 m³, R = 8.314 J / (mol·K), T = 20.95 K, solve the van der Waals equation by iteration to predict the change trend of the storage tank pressure in the next 15 minutes.

[0093] Note: Δn is obtained from the amount of hydrogen substance when m = 0.144 kg. The specific iterative solution process is relatively complex and is usually completed with the help of a computer program.

[0094] 2. Prediction results Assume that the predicted evaporation gas pressure is: P_predict = 1.1 MPa, calculate the BOG generation rate R_bog = 0.144 / 15 ≈ 0.0096 kg / min, and transmit the result to the multi-mode adaptive decision-making module.

[0095] Step Three: Multi-mode adaptive adjustment Assume the second preset pressure P_warning = 1.15 MPa, the first preset pressure P_vent = 1.2 MPa. Since P_predict = 1.1 MPa < P_warning and the fuel cell is in working condition, meeting the conditions for supply processing, enter the priority supply processing mode.

[0096] Specific calculation and control process of the supply processing mode: 1. Obtain the real-time power demand P_fc_demand of the fuel cell.

[0097] Obtain the real-time power demand P_fc_demand = 50 kW through the fuel cell FCU, which is consistent with the previously calculated P_fc_request because the demand power of the fuel cell is stable under the current working conditions.

[0098] 2. Calculate the BOG flow rate.

[0099] Assume that the BOG can be approximately regarded as an ideal gas. According to the ideal gas state equation PV = nRT and relevant data, calculate the BOG flow rate. The molar mass of hydrogen M_H2 = 2×10 -3 kg / mol, then the molar flow rate of BOG is: dot{n}_bog = R_bog / M_H2 = 0.0096 / 2 kg / min × 10 -3 kg / mol = 4.8 mol / min; At the current storage tank pressure P_tank = 0.92683 MPa = 9.2683×10 5 Pa and temperature T_tank = -252.2 °C = 20.95 K, the ideal gas constant R = 8.314 J / (mol·K), and the volume flow rate of BOG is: dot{V}_bog = dot{n}_bog * RT_tank / P_tank = (4.8 mol / min × 8.314 J / (mol•K) × 20.95 K) / (9.2683×10 5 Pa) ≈ 9.02×10 -4 m³ / min.

[0100] 3. Determine the relationship between the energy of BOG and the energy required by the fuel cell.

[0101] The calorific value of hydrogen q_H_2 = 142 MJ / kg, then the energy contained in BOG per unit time is: E_bog = R_bog × q_H2 = 0.0096 × 142×10 3 = 1363.2 kJ / min.

[0102] Convert E_bog to power, the power corresponding to E_bog P_bog = 1363.2 kJ / min × 10 3 / 60 = 22.72 kW. Since P_bog = 22.72 kW < P_fc_demand = 50 kW, directly execute the operation of introducing all BOG into the fuel cell.

[0103] 4. Introduce all BOG into the fuel cell.

[0104] The system sends an instruction. By precisely controlling the BOG flow control valve, all the generated BOG is stably introduced into the fuel cell at a volume flow rate of dot{V}_bog = 9.02×10 -4 m³ / min to meet part of the power demand of the fuel cell. In this process, the fuel cell continuously consumes BOG for power generation to maintain vehicle operation.

[0105] Compared with the prior art, the present invention has the following remarkable advantages: 1) Through innovative forecasting, a shift from traditional passive response management to proactive intelligent management has been achieved. This has greatly reduced the probability and frequency of unsafe emissions, essentially achieving the goal of "zero emissions" and effectively reducing environmental pollution and fuel waste.

[0106] 2) Prioritizing the supply of BOG (Boiler Energy Source) to the fuel cell maximizes BOG fuel utilization. The energy flow of the entire vehicle has been optimized, significantly improving the vehicle's driving range and reducing energy consumption.

[0107] 3) High safety: Multiple modes work together to provide multiple safety guarantees for the system. By always keeping the pressure below the safety threshold, frequent opening and closing of the pressure relief valve is avoided, effectively reducing the safety risks caused by abnormal pressure and ensuring the safety of vehicles and personnel.

[0108] 4) It can comprehensively cope with various complex working conditions. Whether the vehicle is in motion, stationary, short stop or long stop, it can always maintain the efficient and stable operation of the system, demonstrating strong adaptability and reliability.

[0109] The evaporation gas treatment method for a liquid hydrogen supply system proposed in this application obtains the current operating state of the fuel cell; predicts the evaporation gas pressure of the liquid hydrogen storage device within a preset future time; determines the target treatment mode of the evaporation gas based on the evaporation gas pressure, the target preset pressure, and the current operating state of the fuel cell; and treats the evaporation gas according to the target treatment mode. This solves the problem that existing methods for treating evaporation gas from on-board liquid hydrogen storage tanks cannot adaptively manage the gas according to the actual operating state of the vehicle, leading to low overall vehicle energy efficiency and fuel waste. The method enables advance prediction of evaporation gas pressure. By predicting the evaporation gas pressure and monitoring the operating state of the fuel cell, a treatment strategy can be activated in a timely manner to control the evaporation gas in advance, achieving the goals of zero emissions, low energy consumption, and high safety for the on-board liquid hydrogen system, significantly improving the overall performance and reliability of the on-board liquid hydrogen system in fuel cell vehicles.

[0110] Figure 7 A schematic diagram of the structure of a vehicle provided in an embodiment of this application. The vehicle may include: The memory 701, the processor 702, and the computer program stored in the memory 701 and capable of running on the processor 702.

[0111] When the processor 702 executes the program, it implements the evaporation gas treatment method of the liquid hydrogen supply system provided in the above embodiments.

[0112] Furthermore, the vehicle also includes: Communication interface 703 is used for communication between memory 701 and processor 702.

[0113] The memory 701 is used to store computer programs that can run on the processor 702.

[0114] The memory 701 may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk storage device.

[0115] If the memory 701, processor 702, and communication interface 703 are implemented independently, then the communication interface 703, memory 701, and processor 702 can be interconnected via a bus to complete communication between them. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized into address buses, data buses, control buses, etc. For ease of representation, Figure 7 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0116] Optionally, in a specific implementation, if the memory 701, processor 702, and communication interface 703 are integrated on a single chip, then the memory 701, processor 702, and communication interface 703 can communicate with each other through an internal interface.

[0117] The processor 702 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of this application.

[0118] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0119] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0120] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more N executable instructions for implementing custom logic functions or processes, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0121] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequential list of executable instructions for implementing logical functions, and can be specifically implemented in any computer program product for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer program product" can be any means that can contain, store, communicate, propagate, or transmit a program for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples of computer program products (a non-exhaustive list) include the following: an electrical connection having one or N wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic device, and portable optical disc read-only memory (CDROM). Furthermore, the computer program product can even be paper or other suitable medium on which the program can be printed, because the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0122] It should be understood that the various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, the N steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0123] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer program product, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0124] Furthermore, the functional units in the various embodiments of this application can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer program product.

[0125] The computer program product mentioned above may be a read-only memory, a disk, or an optical disk, etc. Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of this application.

Claims

1. A method for treating evaporated gas in a liquid hydrogen supply system, characterized in that, The method includes the following steps: Obtain the current operating status of the fuel cell; Predict the pressure of evaporated gas in a liquid hydrogen storage device within a preset future timeframe; The target processing mode for the evaporated gas is determined based on the evaporated gas pressure, the target preset pressure, and the current operating state of the fuel cell, and the evaporated gas is processed according to the target processing mode.

2. The method according to claim 1, characterized in that, The predicted evaporation gas pressure of the liquid hydrogen storage device within a preset future time period includes: Obtain the current internal temperature and current external ambient temperature of the liquid hydrogen storage device; The current heat transfer rate of the evaporated gas in the liquid hydrogen storage device is calculated based on the current internal temperature and the current external ambient temperature. The vaporization amount of the evaporated gas within the preset future time period is calculated based on the current heat transfer rate, and the vaporization amount of the evaporated gas within the preset future time period is calculated based on the vaporization amount of the evaporated gas within the preset future time period.

3. The method according to claim 1, characterized in that, The step of determining the target processing mode for the evaporated gas based on the evaporated gas pressure, the target preset pressure, and the current operating state of the fuel cell, wherein the target preset pressure includes a first preset pressure and a second preset pressure, comprising: If the pressure of the evaporated gas is less than the second preset pressure and the fuel cell is in operation, then the target processing mode is the supply processing mode. If the pressure of the evaporated gas is greater than or equal to the second preset pressure and less than the first preset pressure, then the target processing mode is the buffer processing mode. If the pressure of the evaporated gas is greater than or equal to the first preset pressure, then the target treatment mode is the emission treatment mode, wherein the second preset pressure is less than the first preset pressure.

4. The method according to claim 3, characterized in that, When processing the evaporated gas according to the supply processing mode, the following is included: Determine the energy of the evaporated gas and obtain the current power demand and available power margin of the fuel cell; If the energy of the evaporated gas is greater than the current power requirement, calculate the power that can be increased in the fuel cell. The power of the fuel cell that can be increased is compared with the available power margin of the fuel cell, and the evaporated gas is processed based on the comparison result of the power of the fuel cell that can be increased and the available power margin of the fuel cell.

5. The method according to claim 4, characterized in that, The step of processing the evaporated gas based on a comparison between the power of the boostable fuel cell and the available power margin of the fuel cell includes: If the power of the boostable fuel cell is less than or equal to the available power margin of the fuel cell, then a portion of the evaporated gas is controlled to be introduced into the fuel cell based on the power of the boostable fuel cell.

6. The method according to claim 5, characterized in that, When the power that can be increased from the fuel cell is greater than the available power margin of the fuel cell, the following includes: According to the real-time power demand of the fuel cell, a portion of the evaporated gas is introduced into the fuel cell, and the excess evaporated gas is discharged to the second buffer device, where the gas can be introduced into the fuel cell.

7. The method according to claim 4, characterized in that, When the energy of the evaporated gas is less than or equal to the current power requirement, including: The evaporated gas is controlled to be introduced into the fuel cell.

8. The method according to claim 3, characterized in that, Processing the evaporated gas according to the buffer processing mode includes: The first pressure relief device is opened to allow the evaporated gas to be passed into the second buffer device for buffering.

9. The method according to claim 3, characterized in that, Treating the evaporated gas according to the emission treatment mode includes: The second pressure relief device is opened to release the hydrogen in the second buffer device to the catalytic device, where it undergoes a chemical reaction before being released into the atmosphere.

10. A vehicle, characterized in that, The system includes a memory, a processor, and a computer program stored in the memory and executable on the processor, the processor executing the program to implement the evaporation gas treatment method of the liquid hydrogen supply system as described in any one of claims 1-9.

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