70MPa vehicle-mounted hydrogen storage tank filling control method and system based on dual-zone model analytical solution

Abstract

A 70MPa on-board hydrogen storage tank filling control method and system based on the analytical solution of the dual-zone model includes the following steps: S1 constructing an information acquisition model: S2 final hydrogen temperature calculation, S3 final hydrogen pressure calculation, S4 final filling time calculation, S5 filling speed calculation, S6 filling stop control. This method has accurate calculation results, and the calculation formula for the final filling time is derived based on the existing formula and known coefficients of the original MC hydrogen filling method, avoiding the problem that the polynomial formula for calculating the final filling time needs to be determined by fitting a large amount of data during the development of the original method, and the coefficients need to be determined by table lookup during use. At the same time, compared with the calculation formula for the final hydrogen temperature in the original MC hydrogen filling method, the final hydrogen temperature calculation formula derived by the dual-zone lumped parameter thermodynamic model of the present invention does not contain the unknown parameter MC, and can quickly and concisely calculate the final hydrogen temperature according to the filling conditions.

Description

Technical Field

[0001] The present invention relates to the field of a hydrogen fuel vehicle refueling protocol algorithm, and in particular to a 70MPa vehicle-mounted hydrogen storage tank refueling control method and system based on a dual-zone model analytical solution. Background Art

[0002] In order to ensure that hydrogen fuel vehicles are refueled quickly and safely, a safe and effective refueling protocol is necessary. The hydrogen refueling protocol currently widely used internationally is the SAE J2601 refueling protocol of the United States, which is issued by the Society of Automotive Engineers (SAE) of the United States. This protocol contains two standard hydrogen refueling methods: the table lookup method and the MC (Mass Capacity) method. The table lookup method tabulates the relationship between the initial refueling conditions and the refueling control parameters in advance. In actual hydrogen refueling events, the hydrogen refueling station selects the required table based on the capacity category of the on-board tank, the precooling temperature level of the hydrogen refueling station, and whether communication refueling is used. The average pressure ramp rate (PRR) used to control the refueling speed and the target pressure used to control the refueling stop in the selected table are determined in combination with the ambient temperature and initial pressure. The MC hydrogen filling method was first proposed by Honda. M stands for mass and C stands for heat capacity. It is referred to as the MC method. This method realizes the processing of the lumped heat capacity (MC) of the tank wall. It uses the ambient temperature measured by the hydrogen filling station, the initial pressure and initial temperature of the hydrogen in the tank, and the temperature and pressure of the conveying gas to dynamically control the filling speed, making the filling speed faster.

[0003] However, both the table lookup method and the MC hydrogen filling method require a large number of simulations under extreme conditions to determine the relevant tables, formulas and coefficients in advance. For example, during the development of the table lookup method, SAE used simulations under extreme conditions to determine 54 separate tables in advance based on information such as the vehicle tank capacity level, the hydrogen filling machine interface type, the precooling temperature category and the delivery pressure category of the hydrogen filling station. During the development of the MC hydrogen filling method, the formula for the final filling time is a polynomial formula determined by fitting a large amount of simulation data, and the coefficients are also determined by a large number of simulations under extreme conditions. SAE has developed specific tables for these coefficients for query during actual use. The development process of developing tables, formulas and coefficients through a large number of simulations under extreme conditions is cumbersome. When the table lookup method and the MC hydrogen filling method are actually used, it is necessary to query the table according to the actual filling conditions to determine the relevant coefficients, and the use process is also cumbersome.

[0004] Therefore, the present invention proposes a new and simpler filling method using analytical solution control to improve the efficiency of the hydrogen filling process. Summary of the invention

[0005] The purpose of the present invention is to overcome the problem of complicated development and use of the filling method in the prior art, and to provide a 70MPa vehicle-mounted hydrogen storage tank filling control method and system based on the analytical solution of the dual-zone model with simple calculation and data fitting.

[0006] To achieve the above objectives, the technical solution of the present invention is:

[0007] A 70MPa vehicle-mounted hydrogen storage tank filling control method based on a dual-zone model analytical solution comprises the following steps:

[0008] S1 Information acquisition: Collect hydrogen tank parameter information of hydrogen filling stations and hydrogen fuel vehicles, and determine whether they meet the filling conditions;

[0009] S2 Final hydrogen temperature calculation, calculates the final hydrogen temperature based on the hydrogen storage tank parameters;

[0010] S3 final hydrogen pressure calculation, calculating the final hydrogen pressure based on the received final hydrogen temperature;

[0011] S4 final filling time calculation, calculating the final filling time based on the received final hydrogen temperature;

[0012] S5: Filling speed calculation, calculating the filling speed based on the received final filling time and final hydrogen pressure;

[0013] S6 filling stop control outputs a filling stop control signal based on the received filling speed and final hydrogen pressure monitoring parameter changes of the hydrogen storage tank.

[0014] In S1, before starting to refuel, the parameter information of the hydrogen refueling station and the hydrogen storage tank of the hydrogen fuel vehicle are collected respectively, and it is determined whether both meet the refueling conditions:

[0015] Collect the inlet temperature T of the hydrogen filling station C and the filling target SOC of the hydrogen storage tank set by the operator target The permissible filling conditions for hydrogen filling stations are: -40℃≤T C ≤-17.5℃,0≤SOC target ≤1;

[0016] Collect the initial pressure P0, initial temperature T0, initial mass m0, volume V, and mass m of the hydrogen tank wall in the hydrogen storage tank of the hydrogen fuel vehicle. w and specific heat capacity C w The permissible refueling conditions for hydrogen fuel vehicles are: 0≤P0≤70MPa, -40℃≤T0≤50℃, 0≤V≤249L at the same time.

[0017] In S2, a dual-zone lumped parameter thermodynamic model of the hydrogen storage tank of the hydrogen filling system is used, that is, the hydrogen storage tank is divided into a hydrogen zone and a tank wall zone, and the tank wall zone is a unified whole with uniform mass and temperature distribution; the analytical solution of the final hydrogen temperature is solved according to the conservation of hydrogen mass and the conservation of energy of hydrogen and tank wall during the filling process;

[0018] The analytical solution for the final hydrogen temperature is: Among them, T final represents the final hydrogen temperature under non-adiabatic conditions, T0 represents the initial temperature of the hydrogen in the tank, T C represents the intake temperature; m0 represents the initial mass of hydrogen, which is calculated using the real gas state equation: Among them, P0 represents the initial pressure of hydrogen in the tank, V represents the internal volume of the tank, represents the molar mass of hydrogen, R represents the universal gas constant, and Z represents the compressibility factor of hydrogen, which can be obtained by looking up the table; m final Represents the final mass of hydrogen, calculated using the mass definition: m final =ρ final ×V, where ρ final Represents the final hydrogen density; m w Represents the mass of the tank wall, C w Represents the specific heat capacity of the tank wall; C p represents the specific heat capacity of hydrogen at constant pressure, C v represents the constant volume specific heat capacity of hydrogen, and γ represents the ratio of the specific heat capacity of hydrogen: γ=c p / c v .

[0019] In S3, the final hydrogen pressure control equation is: final =f(t final , ρ final ), where P final Indicates the final hydrogen pressure in the tank;

[0020] Using a large number of data sets with different hydrogen temperatures T and pressures P for fitting, the final hydrogen pressure control equation is constructed as a polynomial gas state equation:

[0021]

[0022] Among them, a ij represents the coefficients of the equation, Indicates T final to the power of i, Represents ρ final to the jth power.

[0023] In S4, the MC hydrogen filling method is based on the known parameters AC, BC, GC, KC, JC and the final hydrogen temperature Tfinal Calculate the final filling time t final , whose analytical solution is:

[0024]

[0025] Where U0 represents the initial internal energy of hydrogen in the tank; T adiabatic represents the final temperature of hydrogen in the tank under the assumption of adiabatic conditions, U adiabatic represents the final internal energy of hydrogen in the tank under the assumption of adiabatic conditions; m final The final hydrogen mass, AC, BC, GC, KC and JC are fitting coefficients;

[0026] According to the energy conservation law of hydrogen: in, is the average enthalpy of hydrogen entering the tank during the filling process, which can be solved by the Runge-Kutta method:

[0027]

[0028] Among them, the initial hydrogen pressure P at the outlet of the hydrogenator S0 =P0+△P S0 , the real-time hydrogen pressure P at the outlet of the hydrogenator S =P final +△P S ; P0 represents the initial hydrogen pressure in the tank, △P S0 Indicates the pressure drop between the vehicle tank and the hydrogen refueling machine outlet at the initial moment, △P S Indicates the pressure drop between the vehicle tank and the hydrogen refueling machine outlet at the final moment.

[0029] In S5, the filling speed is expressed by the pressure ramp rate PRR, and the control equation is:

[0030] In S6, if any of the following conditions is met, the hydrogen filling is stopped:

[0031] Ps≥P final ;

[0032] T final ≥85℃;

[0033] P final ≥1.25P N ;

[0034] Among them, P N It represents the nominal working pressure of the hydrogen storage tank; Ps=P0+PRR*t, t represents the filling time, and Ps represents the real-time hydrogen pressure at the outlet of the hydrogen filling machine.

[0035] A 70MPa vehicle-mounted hydrogen storage tank filling control system based on a dual-zone model analytical solution, the vehicle-mounted hydrogen storage tank filling control system is used to execute the aforementioned 70MPa vehicle-mounted hydrogen storage tank filling control method based on a dual-zone model analytical solution, specifically comprising:

[0036] The hydrogen filling system comprises: an information acquisition model, a final hydrogen temperature calculation model, a final hydrogen pressure calculation model, a final filling time calculation model, a filling speed calculation model and a filling stop control model;

[0037] Information acquisition model: used to collect parameter information of hydrogen filling stations and hydrogen storage tanks of hydrogen fuel vehicles, and determine whether the filling conditions are met;

[0038] Final hydrogen temperature calculation model: used to calculate the final hydrogen temperature based on hydrogen storage tank parameters;

[0039] Final hydrogen pressure calculation model: used to calculate the final hydrogen pressure based on the received final hydrogen temperature;

[0040] Final filling time calculation model: used to calculate the final filling time based on the received final hydrogen temperature;

[0041] Filling speed calculation model: used to calculate the filling speed based on the received final filling time and final hydrogen pressure;

[0042] Filling stop control model: used to monitor the parameter changes of the hydrogen storage tank based on the received filling speed and final hydrogen pressure and output a filling stop control signal.

[0043] A 70MPa vehicle-mounted hydrogen storage tank filling control device based on a dual-zone model analytical solution, comprising a memory and a processor, wherein the memory is used to store a computer program code and transmit the computer program code to the processor;

[0044] The processor is used to execute the aforementioned 70MPa vehicle-mounted hydrogen storage tank filling control method based on the dual-zone model analytical solution according to the instructions in the computer program code.

[0045] A computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the aforementioned 70MPa vehicle-mounted hydrogen storage tank filling control method based on the analytical solution of the dual-zone model.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] 1. The dual-zone lumped parameter thermodynamic model established in the 70MPa vehicle-mounted hydrogen storage tank filling control method based on the dual-zone model analytical solution of the present invention first calculates the final hydrogen temperature, then calculates the final target pressure and filling time based on the known final hydrogen temperature, and finally calculates the filling rate PRR based on the final target pressure and filling time. The calculation formula for the final filling time in the original MC hydrogen filling method is a polynomial formula generated by fitting a large amount of data t final(j) =a×MATC (j) 3 +b×MATC (j) 2 +c×MATC (j) +d, the formula contains multiple coefficients a, b, c and d, and their values ​​vary with the filling conditions. SAE has developed specific tables for these coefficients for query during use. The calculation formula for the final filling time in this algorithm is based on the existing formula T of the original MC hydrogen filling method final The mathematical formula derived from the known fitting coefficients AC, BC, GC, KC and JC avoids the problem that the coefficients of the polynomial need to be determined by fitting a large amount of data during the development of the original MC hydrogen filling method and the coefficients need to be determined by table lookup during use. The calculation method is simple and the calculation speed is faster.

[0048] 2. The present invention provides a 70MPa vehicle-mounted hydrogen storage tank filling control method based on the analytical solution of the dual-zone model. Compared with the final hydrogen temperature in the original MC hydrogen filling method, The final hydrogen temperature calculation formula derived based on the dual-zone lumped parameter thermodynamic model of the present invention does not contain the unknown parameter MC, and the final hydrogen temperature can be calculated quickly and concisely according to the filling conditions.

[0049] 3. The present invention provides a 70MPa vehicle-mounted hydrogen storage tank filling control system based on a dual-zone model analytical solution, including: an information acquisition model, a final hydrogen temperature calculation model, a final hydrogen pressure calculation model, a final filling time calculation model, a filling speed calculation model, and a filling stop control model. The system is used to implement the steps of the 70MPa vehicle-mounted hydrogen storage tank filling control method based on a dual-zone model analytical solution as provided in any of the above technical solutions. Therefore, the decoding system also includes all the beneficial effects of the 70MPa vehicle-mounted hydrogen storage tank filling control method based on a dual-zone model analytical solution as provided in any of the above technical solutions, which will not be repeated here.

[0050] 4. A 70MPa vehicle-mounted hydrogen storage tank filling control device based on a dual-zone model analytical solution of the present invention includes a processor and a memory, the memory is used to store computer program code, and transmit the computer program code to the processor, and the processor is used to execute the 70MPa vehicle-mounted hydrogen storage tank filling control method based on a dual-zone model analytical solution provided in any of the above technical solutions according to the instructions in the computer program code. Therefore, the device also includes all the beneficial effects of the 70MPa vehicle-mounted hydrogen storage tank filling control method based on a dual-zone model analytical solution provided in any of the above technical solutions, which will not be repeated here.

[0051] 5. A computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the 70MPa vehicle-mounted hydrogen storage tank filling control method based on the dual-zone model analytical solution as provided in any of the above technical solutions. Therefore, the computer-readable storage medium also includes all the beneficial effects of the 70MPa vehicle-mounted hydrogen storage tank filling control method based on the dual-zone model analytical solution as provided in any of the above technical solutions, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 It is a flow chart of the method of the present invention.

[0053] Figure 2 This is the system structure diagram of the present invention

[0054] Figure 3 It is a schematic diagram of the device of the present invention.

[0055] Figure 4 This is a diagram verifying the algorithm effect of the embodiment of the present application. DETAILED DESCRIPTION

[0056] The present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0057] Embodiment 1:

[0058] See also Figure 1 A 70MPa vehicle-mounted hydrogen storage tank filling control method based on the analytical solution of the dual-zone model comprises the following steps:

[0059] S1 Information acquisition: Collect the parameter information of hydrogen storage tanks of hydrogen filling stations and hydrogen fuel vehicles, and determine whether they meet the filling conditions; before starting to fill, collect the parameter information of hydrogen storage tanks of hydrogen filling stations and hydrogen fuel vehicles respectively, and determine whether both meet the filling conditions:

[0060] Collect the inlet temperature T of the hydrogen filling station C and the filling target SOC of the hydrogen storage tank set by the operator targetThe permissible filling conditions for hydrogen filling stations are: -40℃≤T C ≤-17.5℃,0≤SOC target ≤1;

[0061] Collect the initial pressure P0, initial temperature T0, initial mass m0, volume V, and mass m of the hydrogen tank wall in the hydrogen storage tank of the hydrogen fuel vehicle. w and specific heat capacity C w ,,The permissible refueling conditions for hydrogen fuel vehicles are: 0≤P0≤70MPa, -40℃≤T0≤50℃, 0≤V≤249L;

[0062] After refueling begins, the parameter information of the hydrogen refueling station and the hydrogen storage tank of the hydrogen fuel vehicle is updated in real time for information update and calculation of the refueling model.

[0063] S2 Final hydrogen temperature calculation, calculates the final hydrogen temperature based on the hydrogen storage tank parameters;

[0064] Based on the dual-zone lumped parameter thermodynamic model of the hydrogen storage tank of the hydrogen filling system, the hydrogen storage tank is divided into the hydrogen zone and the tank wall zone, and the tank wall zone is a unified whole with uniform mass and temperature distribution; the analytical solution of the final hydrogen temperature is solved according to the mass conservation of hydrogen and the energy conservation of hydrogen and tank wall during the filling process;

[0065] The analytical solution for the final hydrogen temperature is: Where T0 represents the initial temperature of hydrogen, T C represents the intake temperature; m0 represents the initial mass of hydrogen, which is calculated using the real gas state equation: Among them, p0 represents the initial pressure of hydrogen in the tank, V represents the internal volume of the tank, represents the molar mass of hydrogen, and its value is 2.0159×10 -3 (kg / mole), R represents the universal gas constant, whose value is 8.314 (J / mole / K), and Z represents the compressibility factor of hydrogen, which is queried using the database of the National Institute of Standards and Technology (NIST); m final Represents the final mass of hydrogen, calculated using the mass definition: m final =ρ final ×V, where ρ final represents the final hydrogen density, ρ final =SOC target ×ρ(70MPa, 15℃), ρ(70MPa, 15℃)=40.2g / L; m w Represents the mass of the tank wall, C w Represents the specific heat capacity of the tank wall; C p represents the specific heat capacity of hydrogen at constant pressure, Cv represents the constant volume specific heat capacity of hydrogen, and γ represents the ratio of the specific heat capacity of hydrogen: γ=c p / c v ;

[0066] S3 final hydrogen pressure calculation, calculating the final hydrogen pressure based on the received final hydrogen temperature;

[0067] The p final =f(T final , SOC target ) is converted to p final =f(T final , ρ final ), where ρ final =SOC target ×ρ (70MPa，15℃) , ρ (70MPa，15℃) =40.2g / L, and the final hydrogen pressure control equation is constructed as a polynomial gas state equation:

[0068]

[0069] Among them, a ij represents the coefficients of the equation, Indicates T final to the power of i, Represents ρ final The jth power; its value is given by the following table;

[0070] Coefficient values ​​in polynomial gas state equations

[0071]

[0072] S4 final filling time calculation, calculating the final filling time based on the received final hydrogen temperature;

[0073] Based on the MC hydrogen filling method, the known parameters AC, BC, GC, KC, JC and the final hydrogen temperature T are used. final Calculate the final filling time t final , whose analytical solution is:

[0074]

[0075] Where T0 represents the initial temperature of the hydrogen in the tank, U0 represents the initial internal energy of the hydrogen in the tank; T adiabatic represents the final temperature of hydrogen in the tank under the assumption of adiabatic conditions, U adiabatic represents the final internal energy of hydrogen in the tank under the assumption of adiabatic conditions; m final Final hydrogen mass, T finalrepresents the final hydrogen temperature under non-adiabatic conditions; AC, BC, GC, KC and JC are all fitting coefficients, and the values ​​of the fitting coefficients come from the SAE J2601 hydrogen refueling protocol, specifically from the MC method of the American Society of Automotive Engineers for calculating the final hydrogen temperature T in the vehicle tank. final Parameters in the formula MC formula:

[0076] According to the energy conservation law of hydrogen: in, is the average enthalpy of hydrogen entering the tank during the filling process, which can be solved by the Runge-Kutta method:

[0077]

[0078] Among them, T C Indicates the inlet temperature; the initial hydrogen pressure P at the outlet of the hydrogenator S0 =P0+△P S0 , the real-time hydrogen pressure P at the hydrogenation machine outlet S =P final +△P S ; P0 represents the initial hydrogen pressure in the tank, △P S0 Indicates the pressure drop between the vehicle tank and the hydrogen refueling machine outlet at the initial moment, △P S Indicates the pressure drop between the vehicle tank and the hydrogen refueling machine outlet at the final moment.

[0079] S5: Filling speed calculation, calculating the filling speed based on the received final filling time and final hydrogen pressure;

[0080] The filling speed is expressed by the pressure ramp rate PRR, and the filling speed control equation is:

[0081] S6 filling stop control outputs a filling stop control signal based on the received filling speed and final hydrogen pressure monitoring parameter changes of the hydrogen storage tank.

[0082] If any of the following conditions is met, hydrogen filling will be stopped:

[0083] Ps≥P final ;

[0084] T final ≥85℃;

[0085] P final ≥1.25P N ;

[0086] Among them, P N It represents the nominal working pressure of the hydrogen storage tank; Ps=P0+PRR*t, t represents the filling time, and Ps represents the real-time hydrogen pressure at the outlet of the hydrogen filling machine.

[0087] Embodiment 2:

[0088] See also Figure 2 , a 70MPa vehicle-mounted hydrogen storage tank filling control system based on the analytical solution of the dual-zone model, the hydrogen filling system includes: an information acquisition model, a final hydrogen temperature calculation model, a final hydrogen pressure calculation model, a final filling time calculation model, a filling speed calculation model and a filling stop control model;

[0089] Information acquisition model: used to collect parameter information of hydrogen filling stations and hydrogen storage tanks of hydrogen fuel vehicles and transmit the collected information to other models after determining that the filling conditions are met;

[0090] The information acquisition model is used to collect the inlet temperature T of the hydrogen filling station. C and the filling target SOC of the hydrogen storage tank set by the operator target The permissible filling conditions for hydrogen filling stations are: -40℃≤T C ≤-17.5℃,0≤SOC target ≤1;

[0091] The information acquisition model is also used to collect the initial pressure p0 of hydrogen in the hydrogen storage tank of the hydrogen fuel vehicle, the initial temperature T0 of hydrogen, the initial mass m0 of hydrogen, the volume V of the hydrogen storage tank, and the mass m of the hydrogen storage tank wall. w and specific heat capacity c w , the specific heat capacity at constant pressure and specific heat capacity at constant volume of hydrogen; the mass and specific heat capacity of the hydrogen storage tank wall; the target SOC in the tank at the end of filling. The allowable filling conditions for hydrogen fuel vehicles are: 0≤p0≤70MPa, -40℃≤T0≤50℃, 0≤V≤249L are met at the same time.

[0092] Final hydrogen temperature calculation model: used to calculate the final hydrogen temperature T based on the information collected by the information acquisition model final Output to the final hydrogen pressure calculation model, the final filling time calculation model and the filling speed calculation model;

[0093] The final hydrogen temperature calculation model is constructed based on the dual-zone lumped parameter thermodynamic model of the hydrogen storage tank of the hydrogen filling system, using the assumption that the tank wall temperature is equal to the hydrogen temperature and the adiabatic boundary similar to the MC hydrogen filling method.

[0094]

[0095] Where m0 represents the initial mass of hydrogen; m final Represents the final mass of hydrogen; m w Represents the mass of the tank wall, C wrepresents the specific heat capacity of the tank wall; T0 represents the initial temperature of hydrogen; T C Indicates the intake air temperature; C p represents the specific heat capacity of hydrogen at constant pressure, C v represents the constant volume specific heat capacity of hydrogen, and γ represents the ratio of the specific heat capacity of hydrogen: γ=c p / c v .

[0096] Final hydrogen pressure calculation model: used to calculate the final hydrogen pressure P based on the received final hydrogen temperature final Output to the filling speed calculation model and the filling stop control model;

[0097] A large number of discrete data of hydrogen temperature T and pressure P are combined to obtain a large number of data sets (P, T) with different hydrogen temperatures and pressures. A large number of data sets (P, T and ρ) with different hydrogen temperatures, pressures and densities are calculated using the "black box" implicit model of the National Institute of Standards and Technology (NIST) database. Finally, a polynomial "white box" explicit model is constructed using a mathematical fitting method, as follows:

[0098]

[0099] Final filling time calculation model: used to calculate the final filling time t based on the received final hydrogen temperature final Output to the filling speed calculation model;

[0100] The formula for the final hydrogen temperature derived from the simplified tank model based on the MC hydrogen filling method and the formula for the MC parameters are solved to obtain the analytical solution for the final filling time:

[0101]

[0102] Where T0 represents the initial temperature of the hydrogen in the tank, U0 represents the initial internal energy of the hydrogen in the tank; T adiabatic represents the final temperature of hydrogen in the tank under the assumption of adiabatic conditions, U adiabatic represents the final internal energy of hydrogen in the tank under the assumption of adiabatic conditions; m final Final hydrogen mass, T final represents the final hydrogen temperature under non-adiabatic conditions. AC, BC, GC, KC and JC are all fitting coefficients. The values ​​of the fitting coefficients come from the SAE J2601 hydrogen refueling protocol, specifically from the MC method of the American Society of Automotive Engineers for calculating the final hydrogen temperature T in the vehicle tank. final Parameters in the formula MC formula:

[0103] Filling speed calculation model: used to calculate the filling speed based on the received final filling time and final hydrogen pressure, expressed by the pressure ramp rate PRR, and output to the filling stop control model;

[0104] The filling speed control equation is: Among them, P final represents the final pressure of hydrogen in the hydrogen storage tank, P0 represents the initial pressure of hydrogen in the storage tank, t final Indicates the final filling time;

[0105] Filling stop control model: used to output a filling stop control signal based on the received filling speed and final hydrogen pressure.

[0106] If any of the following conditions is met, hydrogen filling will be stopped:

[0107] Ps≥P final ;

[0108] T final ≥85℃;

[0109] P final ≥1.25P N ;

[0110] Among them, P N It represents the nominal working pressure of the hydrogen storage tank; Ps=P0+PRR*t, t represents the filling time, and Ps represents the real-time hydrogen pressure at the outlet of the hydrogen filling machine.

[0111] Embodiment 3:

[0112] See also Figure 3 , a 70MPa vehicle-mounted hydrogen storage tank filling control device based on a dual-zone model analytical solution, comprising a memory and a processor, wherein the memory is used to store a computer program code and transmit the computer program code to the processor;

[0113] The processor is used to execute the aforementioned 70MPa vehicle-mounted hydrogen storage tank filling control method based on the dual-zone model analytical solution according to the instructions in the computer program code.

[0114] Embodiment 4:

[0115] A computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the aforementioned 70MPa vehicle-mounted hydrogen storage tank filling control method based on the analytical solution of the dual-zone model.

[0116] Performance Verification:

[0117] In order to verify the effectiveness of the filling control method proposed in the present invention, the geometric parameters and physical parameters of a 25L III type storage tank are used for simulation comparison. The reason for using a 25L III type storage tank is that this method has five fitting coefficients, namely AC, BC, JC, GC and KC. The original MC hydrogen filling method also uses the parameters of a 25L III type storage tank, and the values ​​of these five parameters are determined by combining the simulation of the zero-dimensional gas one-dimensional tank wall (0D1D) model. The initial and boundary conditions used in the verification process are shown in the following table.

[0118]

[0119] Figure 4 The simulation results of the filling control method proposed in the present invention and the 0D1D model are compared when the ambient temperature is 0°C and 20°C, the intake temperature is -20°C, -10°C and 0°C, and the initial pressure is 2MPa, 6MPa and 10MPa. The 0D1D model takes into account the complex tank wall structure and heat transfer conditions, and its calculation results can be considered accurate and can be used as a standard. In general, the final hydrogen temperature, pressure and SOC of the filling control method proposed in the present invention are in good agreement with those of the 0D1D model, proving the reliability of the 70MPa on-board hydrogen storage tank filling control method and system based on the analytical solution of the dual-zone model proposed in the present invention.

Claims

1. A 70MPa vehicle-mounted hydrogen storage tank filling control method based on the analytical solution of the dual-zone model, characterized in that: The steps include: S1 Information acquisition: Collect hydrogen tank parameter information of hydrogen filling stations and hydrogen fuel vehicles, and determine whether they meet the filling conditions; S2 Final hydrogen temperature calculation, calculates the final hydrogen temperature based on the hydrogen storage tank parameters; Based on the dual-zone lumped parameter thermodynamic model of the hydrogen storage tank of the hydrogen filling system, the hydrogen storage tank is divided into the hydrogen zone and the tank wall zone, and the tank wall zone is a unified whole with uniform mass and temperature distribution; the analytical solution of the final hydrogen temperature is solved according to the mass conservation of hydrogen and the energy conservation of hydrogen and tank wall during the filling process; The analytical solution for the final hydrogen temperature is: Among them, T final represents the final hydrogen temperature under non-adiabatic conditions, T0 represents the initial temperature of the hydrogen in the tank, T C represents the intake temperature; m0 represents the initial mass of hydrogen, which is calculated using the real gas state equation: Among them, P0 represents the initial pressure of hydrogen in the tank, V represents the internal volume of the tank, represents the molar mass of hydrogen, R represents the universal gas constant, and Z represents the compressibility factor of hydrogen, which can be obtained by looking up the table; m final Represents the final mass of hydrogen, calculated using the mass definition: m final =ρ final ×V, where ρ final Represents the final hydrogen density; m w Represents the mass of the tank wall, C w Represents the specific heat capacity of the tank wall; C p represents the specific heat capacity of hydrogen at constant pressure, C v represents the constant volume specific heat capacity of hydrogen, and γ represents the ratio of the specific heat capacity of hydrogen: γ=c p / c v ; S3 final hydrogen pressure calculation, calculating the final hydrogen pressure based on the received final hydrogen temperature; S4 final filling time calculation, calculating the final filling time based on the received final hydrogen temperature; S5: Filling speed calculation, calculating the filling speed based on the received final filling time and final hydrogen pressure; S6 filling stop control outputs a filling stop control signal based on the received filling speed and final hydrogen pressure monitoring parameter changes of the hydrogen storage tank.

2. A 70MPa vehicle-mounted hydrogen storage tank filling control method based on a dual-zone model analytical solution according to claim 1, characterized in that: In S1, before starting to refuel, the parameter information of the hydrogen refueling station and the hydrogen storage tank of the hydrogen fuel vehicle are collected respectively, and it is determined whether both meet the refueling conditions: Collect the inlet temperature T of the hydrogen filling station C and the filling target SOC of the hydrogen storage tank set by the operator target The permissible filling conditions for hydrogen filling stations are: -40℃≤T C ≤-17.5℃,0≤SOC target ≤1; Collect the initial pressure P0, initial temperature T0, initial mass m0, volume V, and mass m of the hydrogen tank wall in the hydrogen storage tank of the hydrogen fuel vehicle. w and specific heat capacity C w The permissible refueling conditions for hydrogen fuel vehicles are: 0≤P0≤70MPa, -40℃≤T0≤50℃, 0≤V≤249L at the same time.

3. A 70MPa vehicle-mounted hydrogen storage tank filling control method based on a dual-zone model analytical solution according to claim 1 or 2, characterized in that: In S3, the final hydrogen pressure control equation is: final =f(T final , ρ final ), where P final Indicates the final hydrogen pressure in the tank; Using a large number of data sets with different hydrogen temperatures T and pressures P for fitting, the final hydrogen pressure control equation is constructed as a polynomial gas state equation: Among them, a ij represents the coefficients of the equation, Indicates T final to the power of i, Represents ρ final to the jth power.

4. A 70MPa vehicle-mounted hydrogen storage tank filling control method based on a dual-zone model analytical solution according to claim 3, characterized in that: In S4, the MC hydrogen filling method is based on the known parameters AC, BC, GC, KC, JC and the final hydrogen temperature T final Calculate the final filling time t final , whose analytical solution is: Where U0 represents the initial internal energy of hydrogen in the tank; T adiabatic represents the final temperature of hydrogen in the tank under the assumption of adiabatic conditions, U adiabatic represents the final internal energy of hydrogen in the tank under the assumption of adiabatic conditions; m final The final hydrogen mass, AC, BC, GC, KC and JC are fitting coefficients; According to the energy conservation law of hydrogen: in, is the average enthalpy of hydrogen entering the tank during the filling process, which can be solved by the Runge-Kutta method: Among them, the initial hydrogen pressure P at the outlet of the hydrogenator S0 =P0+△P S0 , the real-time hydrogen pressure P at the outlet of the hydrogenator S =P final +△P S ; P0 represents the initial hydrogen pressure in the tank, △P S0 Indicates the pressure drop between the vehicle tank and the hydrogen refueling machine outlet at the initial moment, △P S Indicates the pressure drop between the vehicle tank and the hydrogen refueling machine outlet at the final moment.

5. A 70MPa vehicle-mounted hydrogen storage tank filling control method based on a dual-zone model analytical solution according to claim 4, characterized in that: In S5, the filling speed is expressed by the pressure ramp rate PRR, and the control equation is:

6. A 70MPa vehicle-mounted hydrogen storage tank filling control method based on a dual-zone model analytical solution according to claim 1, characterized in that: In S6, if any of the following judgment conditions is met, the hydrogen filling is stopped: Ps≥P final ; T final ≥85℃； P final ≥1.25P N ; Among them, P N It represents the nominal working pressure of the hydrogen storage tank; Ps=P0+PRR*t, t represents the filling time, and Ps represents the real-time hydrogen pressure at the outlet of the hydrogen filling machine.

7. A 70MPa vehicle-mounted hydrogen storage tank filling control system based on the analytical solution of the dual-zone model, characterized in that: The vehicle-mounted hydrogen storage tank filling control system is used to execute the 70MPa vehicle-mounted hydrogen storage tank filling control method based on the dual-zone model analytical solution according to any one of claims 1 to 6, specifically comprising: The hydrogen filling system comprises: an information acquisition model, a final hydrogen temperature calculation model, a final hydrogen pressure calculation model, a final filling time calculation model, a filling speed calculation model and a filling stop control model; Information acquisition model: used to collect parameter information of hydrogen filling stations and hydrogen storage tanks of hydrogen fuel vehicles, and determine whether the filling conditions are met; Final hydrogen temperature calculation model: used to calculate the final hydrogen temperature based on hydrogen storage tank parameters; Final hydrogen pressure calculation model: used to calculate the final hydrogen pressure based on the received final hydrogen temperature; Final filling time calculation model: used to calculate the final filling time based on the received final hydrogen temperature; Filling speed calculation model: used to calculate the filling speed based on the received final filling time and final hydrogen pressure; Filling stop control model: used to monitor the parameter changes of the hydrogen storage tank based on the received filling speed and final hydrogen pressure and output a filling stop control signal.

8. A 70MPa vehicle-mounted hydrogen storage tank filling control device based on the analytical solution of the dual-zone model, characterized in that: The method comprises a memory and a processor, wherein the memory is used to store computer program code and transmit the computer program code to the processor; The processor is used to execute the 70MPa vehicle-mounted hydrogen storage tank filling control method based on the dual-zone model analytical solution as described in any one of claims 1 to 6 according to the instructions in the computer program code.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, which, when executed by a processor, implements the 70MPa vehicle-mounted hydrogen storage tank filling control method based on the dual-zone model analytical solution as described in any one of claims 1 to 6.

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