Filling temperature rise control method for vehicle-mounted hydrogen adding cylinder
By combining CFD simulation and flow control valve model with genetic algorithm to optimize hydrogen refueling flow rate, the problem of inaccurate temperature rise control in high-pressure, high-flow refueling was solved, achieving safe, fast and low-energy hydrogen refueling.
Patent Information
- Application Number
- CN202511790651.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-01
- Publication Date
- 2026-02-03
AI Technical Summary
In existing technologies, the temperature rise control during high-pressure, high-flow hydrogen refueling is inaccurate, which limits the refueling rate, increases energy consumption and operating costs, and makes it difficult to meet the rapid refueling needs of hydrogen-powered commercial vehicles.
By establishing a CFD simulation model and a second-order mathematical model of the flow regulating valve, and combining genetic algorithms and control algorithms, the temperature rise and pressure rise during the hydrogen refueling process are precisely controlled. Real-time flow velocity boundaries and control algorithms are designed to optimize the refueling process.
It achieves safety, speed and low energy consumption in hydrogen refueling, improves refueling rate, reduces operating costs, and meets the rapid refueling needs of hydrogen-powered commercial vehicles.
Smart Images
Figure CN121452482A_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of hydrogen refueling technology, specifically relating to a method for controlling the temperature rise during the filling of vehicle-mounted hydrogen cylinders, which is applied to the safe, rapid, and low-energy refueling of high-pressure hydrogen. Background Technology
[0002] Hydrogen energy utilization is a crucial direction for global energy transition and upgrading, holding a strategic position in the future energy structure. Currently, the hydrogen energy industry has achieved considerable scale, yielding a number of technological research and application results. As hydrogen fuel cell technologies mature globally, hydrogen transportation has become one of the main application scenarios for hydrogen energy. my country ranks first in the world in cumulative promotion of hydrogen fuel cell vehicles, with commercial vehicles such as heavy-duty trucks and buses accounting for over 90%. Hydrogen-powered heavy-duty trucks, characterized by long driving range and fast refueling, are expected to become the mainstay of long-haul transportation.
[0003] As a key infrastructure for hydrogen energy utilization, hydrogen refueling stations urgently need the development of high-density, large-capacity, rapid hydrogen refueling technology. Currently, the refueling capacity of existing hydrogen refueling stations is insufficient to meet the needs of large-scale applications involving hundreds or even thousands of hydrogen-powered commercial vehicles, and the proportion of refueling stations with a capacity of 1000 kg / day or more lags behind that of foreign countries. For example, hydrogen-powered heavy trucks, railway locomotives, and ships have a hydrogen storage capacity of 50 to 150 kg. Refueling using a traditional 35 MPa hydrogen refueling machine would take more than 50 minutes, while using a 70 MPa high-pressure hydrogen refueling machine with a refueling flow rate ≥7.2 kg / min can shorten the refueling time to 20 minutes, significantly improving operational efficiency. Furthermore, the hydrogen storage density at 70 MPa is 60% higher than at 35 MPa, which can increase the driving range to over 700 kilometers.
[0004] However, high-pressure, high-flow-rate refueling technology faces multiple bottlenecks, mainly concentrated in extreme temperature rise issues, leakage and explosion hazards, and infrastructure and operating costs. The temperature rise during high-pressure, high-flow-rate refueling is primarily caused by the combined effects of gas compression heat, material thermal conductivity, and the structure of the hydrogen storage cylinder. Although some rapid refueling tests of high-pressure hydrogen storage cylinders for vehicles have been completed both domestically and internationally, the mechanism of the rapid refueling temperature rise process is still not fully understood, and precise temperature rise control has not yet been achieved. The mainstream control method still relies on empirical data and excessive redundancy control to ensure that the temperature rise does not exceed the safe value, which restricts further improvements in refueling rate and increases energy consumption and operating costs, hindering widespread application. Summary of the Invention
[0005] The purpose of this application is to provide a method for controlling the temperature rise during the filling of a vehicle-mounted hydrogen refueling cylinder, solving the following problems: During high-pressure, high-flow hydrogen refueling, the compression effect causes the hydrogen gas inside the cylinder to be continuously compressed, releasing heat; the throttling effect causes the Joule-Thompson coefficient of hydrogen to be negative, requiring heat release when the source hydrogen gas changes from a high-pressure state to a low-pressure state; and the kinetic energy conversion effect causes the high-pressure hydrogen gas to rapidly increase in volume and mix with the residual low-pressure hydrogen gas inside the cylinder when entering the storage cylinder, after which the original high-pressure hydrogen gas velocity will decrease. The temperature will drop, and during this process, some of the kinetic energy of the original high-pressure hydrogen will be converted into the thermal energy of the mixed hydrogen in the cylinder; thus, the cylinder temperature will rise rapidly during the hydrogen filling process. Although there are some successful cases of rapid filling tests of high-pressure hydrogen storage cylinders for vehicles at home and abroad, the research on the mechanism of rapid filling temperature rise is not yet thorough, and precise temperature rise control has not yet been achieved. The mainstream control method is still to ensure that the temperature rise does not exceed the safe value by using excessive redundancy control based on empirical data, which restricts the further improvement of the filling rate and increases energy consumption and operating costs, which is not conducive to promotion and application.
[0006] The objective of this application is achieved through the following technical solution: A method for controlling the temperature rise during the filling of an on-board hydrogen refueling cylinder includes the following steps: S1. Establish a CFD simulation model based on the cylinder parameters, study the relationship between different external parameters and cylinder temperature / pressure rise, and establish a mathematical model of external parameters and cylinder temperature / pressure rise. S2, Based on the flow characteristic curve and working principle of the flow control valve, establish a second-order mathematical model of the flow control valve: (1); Where m1 is the mass of the moving parts of the valve core, x is the displacement of the valve core, c is the damping coefficient, k is the equivalent stiffness of the diaphragm plus the spring stiffness, Ap is the effective area of the diaphragm, Pa is the control air pressure, Ffluid is the fluid force, and Fc is the Coulomb friction resistance. S3, based on the current cylinder and external parameters and the preset maximum flow rate, predicts the current highest hydrogen temperature through a mathematical model of cylinder temperature rise / pressure rise determined by CFD simulation, thereby reducing the energy consumption of the chiller unit while ensuring safety. S4, based on the current cylinder and external parameters and the highest hydrogen temperature predicted by S3, utilizes the mathematical model of cylinder temperature rise / pressure rise, constraints and optimization objectives, and employs a genetic algorithm to plan the real-time flow velocity boundary during refueling. Based on the planned flow velocity boundary and control technical indicators, a control algorithm is designed. S5 uses a control algorithm to control the injection flow rate, ensuring the speed, stability, and steady-state tracking error of the flow rate.
[0007] Furthermore, in S1, the cylinder parameters include one or more of the following: cylinder volume, size, shape, and material; and the external parameters include one or more of the following: flow rate, hydrogen temperature, ambient temperature, and initial cylinder pressure.
[0008] Furthermore, in S2, Ffluid in formula (1) is related to the pressure difference across the regulating valve ( P), a function of the current flow rate (Q) through the valve.
[0009] Furthermore, in S2, Fc in formula (1) is ignored.
[0010] Furthermore, in S2, an experiment is designed to verify the accuracy of the second-order mathematical model of the flow control valve. Data on the inlet pressure Pi, outlet pressure Po, mass flow rate f, medium temperature T, and pilot valve driving force Pc of the flow control valve are collected through the hydrogenation machine control board to verify the accuracy of the second-order mathematical model of the control valve.
[0011] Furthermore, in S3, the gas cylinder and external parameters include one or more of the following: ambient temperature, initial pressure of the gas cylinder, gas cylinder type, and gas cylinder volume.
[0012] Furthermore, in S3, a margin of at least 10% is reserved for the highest hydrogen temperature to reduce energy consumption.
[0013] Furthermore, in S4, the safe temperature is no more than 85°C.
[0014] Furthermore, in S4, the optimization constraint condition is as follows: (2); Optimal objective function: (3); Where SOC is the saturated filling rate, Tmax is the maximum temperature of the cylinder, Pmax is the maximum pressure of the cylinder, P(end) is the current real-time cylinder pressure, P(set) is the target filling pressure of the cylinder, tmin is the minimum filling time, m is the mass of hydrogen that can be filled, q is the real-time flow rate, TH2_max is the maximum hydrogen pre-cooling temperature, H2_rflow is the real-time filling flow rate, and H2_tflow is the theoretically calculated maximum flow rate.
[0015] Furthermore, the Saturated Fill Rate (SOC): (4); Wherein, ρ(70MPa,15℃) is the hydrogen density under the rated hydrogen storage pressure of 70MPa and temperature of 15℃, and ρ(P,T) is the hydrogen density of the hydrogen cylinder under the current pressure P and temperature T.
[0016] Furthermore, in S5, the LEVANT differential STA control algorithm is used to control the injection flow rate.
[0017] The beneficial effects of this application are as follows: By employing key technologies such as temperature rise characteristics and system thermo-mechanical coupling mechanism, multi-physics field dynamic coupling research on the analysis of the temperature rise law inside the cylinder during rapid hydrogen refueling, dynamic coupling modeling of material thermophysical properties and temperature field, and multi-parameter dynamic influence modeling and control of quasi-adiabatic refueling system, the application achieves precise control, safety monitoring, and energy consumption reduction in hydrogen refueling under multiple constraints such as temperature rise, pressure, and SOC, thus realizing the safety, low energy consumption, and speed of hydrogen refueling.
[0018] The aforementioned main solution and its various further alternatives can be freely combined to form multiple solutions, all of which are solutions that can be adopted and are claimed in this application; furthermore, the (non-conflicting alternatives) can also be freely combined with each other and with other alternatives. Those skilled in the art, after understanding the solution of this application, will realize from the prior art and common general knowledge that there are many combinations, all of which are technical solutions to be protected by this application, and will not be exhaustively listed here. Attached Figure Description
[0019] Figure 1 This is a flowchart illustrating the process of this application.
[0020] Figure 2 This is a schematic diagram of model verification in S2 of this application.
[0021] Figure 3 This is a schematic diagram of the S3 process of this application.
[0022] Figure 4 This is a schematic diagram of the S5 process for this application. Figure 1 .
[0023] Figure 5 This is a schematic diagram of the S5 process for this application. Figure 2 . Detailed Implementation
[0024] The following non-limiting embodiments are used to illustrate this application.
[0025] Example 1 refer to Figures 1-5 As shown, a method for controlling the temperature rise during filling of a vehicle-mounted hydrogen refueling cylinder includes the following steps: S1, establishing a CFD (Computational Fluid Dynamics) simulation model based on the cylinder parameters, studying the relationship between different external parameters and the cylinder temperature rise / pressure rise, and establishing a mathematical model of the relationship between external parameters and the cylinder temperature rise / pressure rise.
[0026] The parameters of the gas cylinder include its volume, size, shape, and materials, while the external parameters include flow rate, hydrogen temperature, ambient temperature, and initial pressure of the gas cylinder.
[0027] S2, Based on the flow characteristic curve and working principle of the flow control valve, establish a second-order mathematical model of the flow control valve: (1); Where m1 is the mass of the moving parts of the valve core, x is the displacement of the valve core, c is the damping coefficient, k is the equivalent stiffness of the diaphragm plus the spring stiffness, Ap is the effective area of the diaphragm, Pa is the control air pressure, Ffluid is the fluid force, and Fc is the Coulomb friction resistance. Ffluid is the pressure difference across the control valve (…). P), a function of the current flow rate (Q) through the valve.
[0028] Since Fc is usually very small, Fc in formula (1) can be ignored.
[0029] refer to Figure 2 As shown, an experiment was designed to verify the accuracy of the second-order mathematical model of the flow control valve. Data on the inlet pressure Pi, outlet pressure Po, mass flow rate f, medium temperature T, and pilot valve driving force Pc of the flow control valve were collected through the hydrogenation machine control board to verify the accuracy of the second-order mathematical model of the control valve.
[0030] refer to Figure 3 As shown in Figure S3, based on the current cylinder and external parameters and the preset maximum flow rate, the current maximum hydrogen temperature is predicted by the mathematical model of cylinder temperature rise / pressure rise determined by CFD simulation, thereby reducing the energy consumption of the chiller unit while ensuring safety; at least 10% margin is reserved for the maximum hydrogen temperature to ensure refueling safety.
[0031] The parameters of the gas cylinder and the external environment include ambient temperature, initial pressure of the gas cylinder, type of gas cylinder, and volume of gas cylinder.
[0032] S4. Based on the current cylinder and external parameters, using a mathematical model of cylinder temperature rise / pressure rise, predict the maximum flow rate at which the cylinder temperature will not exceed the safe temperature under the current hydrogen temperature. Cylinder and external parameters include ambient temperature, initial cylinder pressure, cylinder type, and cylinder volume. The safe temperature is no more than 85℃.
[0033] Based on the current cylinder and external parameters, and the predicted maximum hydrogen temperature from S3, a genetic algorithm is used to plan the real-time flow velocity boundary during refueling, utilizing a mathematical model of cylinder temperature / pressure rise, constraints, and optimization objectives. The control algorithm is then designed based on the planned flow velocity boundary and control technical indicators. Optimization constraints: (2); Optimal objective function: (3); Where SOC is the saturated filling rate, Tmax is the maximum temperature of the cylinder, Pmax is the maximum pressure of the cylinder, P(end) is the current real-time cylinder pressure, P(set) is the target filling pressure of the cylinder, tmin is the minimum filling time, m is the mass of hydrogen that can be filled, q is the real-time flow rate, TH2_max is the maximum hydrogen pre-cooling temperature, H2_rflow is the real-time filling flow rate, and H2_tflow is the theoretically calculated maximum flow rate.
[0034] Saturated Fill Rate (SOC): (4); Wherein, ρ(70MPa,15℃) is the hydrogen density under the rated hydrogen storage pressure of 70MPa and temperature of 15℃, and ρ(P,T) is the hydrogen density of the hydrogen cylinder under the current pressure P and temperature T.
[0035] refer to Figure 4 / Figure 5 As shown in Figure S5, the injection flow rate is controlled by a control algorithm. The LEVANT differential plus STA (super spiral sliding membrane control) control algorithm is used to control the injection flow rate, ensuring the speed, stability and steady-state tracking error of the flow rate.
[0036] The foregoing basic examples and their further alternative examples can be freely combined to form multiple embodiments, all of which are embodiments that can be adopted and claimed in this application. In the scheme of this application, each alternative example can be arbitrarily combined with any other basic example and alternative example.
[0037] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A method for controlling the temperature rise during filling of a vehicle-mounted hydrogen refueling cylinder, characterized in that, Includes the following steps: S1. Establish a CFD simulation model based on the cylinder parameters, study the relationship between different external parameters and cylinder temperature / pressure rise, and establish a mathematical model of external parameters and cylinder temperature / pressure rise. S2, Based on the flow characteristic curve and working principle of the flow control valve, establish a second-order mathematical model of the flow control valve: （1）； Where m1 is the mass of the moving parts of the valve core, x is the displacement of the valve core, c is the damping coefficient, k is the equivalent stiffness of the diaphragm plus the spring stiffness, Ap is the effective area of the diaphragm, Pa is the control air pressure, Ffluid is the fluid force, and Fc is the Coulomb friction resistance. S3, based on the current cylinder and external parameters and the preset maximum flow rate, predicts the current highest hydrogen temperature through a mathematical model of cylinder temperature rise / pressure rise determined by CFD simulation, thereby reducing the energy consumption of the chiller unit while ensuring safety. S4, based on the current cylinder and external parameters and the highest hydrogen temperature predicted by S3, utilizes the mathematical model of cylinder temperature rise / pressure rise, constraints and optimization objectives, and employs a genetic algorithm to plan the real-time flow velocity boundary during refueling. Based on the planned flow velocity boundary and control technical indicators, a control algorithm is designed. S5 uses a control algorithm to control the injection flow rate, ensuring the speed, stability, and steady-state tracking error of the flow rate.
2. The method for controlling the temperature rise during filling of an on-board hydrogen refueling cylinder according to claim 1, characterized in that: In S1, the cylinder parameters include one or more of the following: cylinder volume, size, shape, and material; the external parameters include one or more of the following: flow rate, hydrogen temperature, ambient temperature, and initial cylinder pressure.
3. The method for controlling the temperature rise during filling of an on-board hydrogen refueling cylinder according to claim 1, characterized in that: In S2, Ffluid in formula (1) is related to the pressure difference across the regulating valve ( P), a function of the current flow rate (Q) through the valve.
4. The method for controlling the temperature rise during filling of an on-board hydrogen refueling cylinder according to claim 1 or 3, characterized in that: In S2, Fc in formula (1) is ignored.
5. The method for controlling the temperature rise during filling of an on-board hydrogen refueling cylinder according to claim 1, characterized in that: In S2, an experiment is designed to verify the accuracy of the second-order mathematical model of the flow control valve. Data on the inlet pressure Pi, outlet pressure Po, mass flow rate f, medium temperature T, and pilot valve driving force Pc of the flow control valve are collected through the hydrogenation machine control board to verify the accuracy of the second-order mathematical model of the control valve.
6. The method for controlling the temperature rise during filling of an on-board hydrogen refueling cylinder according to claim 1, characterized in that: In S3, the gas cylinder and external parameters include one or more of the following: ambient temperature, initial pressure of the gas cylinder, gas cylinder type, and gas cylinder volume.
7. The method for controlling the temperature rise during filling of an on-board hydrogen refueling cylinder according to claim 1, characterized in that: In S3, a margin of at least 10% is reserved for the highest hydrogen temperature to reduce energy consumption; in S4, the safe temperature is no more than 85°C.
8. The method for controlling the temperature rise during filling of an on-board hydrogen refueling cylinder according to claim 1, characterized in that: In S4, the optimization constraint condition is as follows: （2）； Optimal objective function: （3）； Where SOC is the saturated filling rate, Tmax is the maximum temperature of the cylinder, Pmax is the maximum pressure of the cylinder, P(end) is the current real-time cylinder pressure, P(set) is the target filling pressure of the cylinder, tmin is the minimum filling time, m is the mass of hydrogen that can be filled, q is the real-time flow rate, TH2_max is the maximum hydrogen pre-cooling temperature, H2_rflow is the real-time filling flow rate, and H2_tflow is the theoretically calculated maximum flow rate.
9. The method for controlling the temperature rise during filling of an on-board hydrogen refueling cylinder according to claim 8, characterized in that: The Saturated Fill Rate (SOC) is as follows: （4）； Wherein, ρ(70MPa,15℃) is the hydrogen density under the rated hydrogen storage pressure of 70MPa and temperature of 15℃, and ρ(P,T) is the hydrogen density of the hydrogen cylinder under the current pressure P and temperature T.
10. The method for controlling the temperature rise during filling of an on-board hydrogen refueling cylinder according to claim 1, characterized in that: In S5, the LEVANT differential plus STA control algorithm is used to control the injection flow rate.