A safe operation method of an integrated station of electricity and hydrogen considering temperature change of a hydrogen tank

Abstract

The present application provides a kind of hydrogen tank temperature variation considering the safe operation method of electric hydrogen integrated station, comprising the following steps: S1, by the Monte Carlo simulation to the service vehicle to station time probability density function provided, obtain the load curve of electric hydrogen integrated station;S2, establish the mathematical programming model of each component in electric hydrogen integrated station;S3, each part parameter is input into model, and first relaxation solution is carried out using commercial software gurobi;S4, according to the temperature change of solution result, add net speed and constraint to model;S5, the model after adding constraint is solved again;S6, judge whether temperature is in safe range, not in safe range then return to step S4, in safe range or reach maximum iteration number then enter seventh step;S7, obtain the scheduling scheme of electric hydrogen integrated station hydrogen storage tank safe operation.The present application considers the temperature change of hydrogen tank charging and discharging process, and obtains the practical and feasible scheduling scheme with less loss of interest.

Description

Technical Field

[0001] This invention relates to hydrogen energy technology, and in particular to a method for the safe operation of an integrated electric-hydrogen station that takes into account temperature changes in hydrogen tanks. Background Technology

[0002] With the increasing use of fossil fuels and rising carbon dioxide emissions, global concern about environmental and climate change is rapidly intensifying. Green hydrogen, as a novel secondary energy carrier, boasts advantages such as zero carbon emissions and high energy density, making it suitable for decarbonization in industries like power, chemicals, metallurgy, and transportation. Therefore, one strategy for mitigating climate change is to utilize surplus renewable energy to produce green hydrogen. With the continuous advancement and application of hydrogen energy technology, integrated electric-hydrogen stations have become an important clean energy facility, widely used in the refueling and charging processes of hydrogen fuel cell vehicles and electric vehicles. These stations produce hydrogen through water electrolysis and compress and store it to fuel hydrogen fuel cell vehicles. With the rapid development of the hydrogen energy industry, the construction and application of integrated electric-hydrogen stations are gradually increasing.

[0003] However, current integrated electric-hydrogen stations do not adequately consider temperature changes during hydrogen tank filling and discharging in their design and operation. The hydrogen tank generates heat during filling and discharging, causing the tank temperature to rise, which may affect the stability and safety of the hydrogen tank. Excessive temperature can lead to overheating, excessive pressure, and other safety hazards, even causing serious consequences such as explosions. Therefore, to ensure the safe operation of integrated electric-hydrogen stations, it is essential to strengthen the research and monitoring of temperature changes during hydrogen tank filling and discharging. This will improve the safety and reliability of integrated electric-hydrogen stations. In future design and operation of integrated electric-hydrogen stations, greater emphasis should be placed on the impact of hydrogen tank temperature changes on safety, thereby comprehensively improving the safety level of integrated electric-hydrogen stations.

[0004] Currently, most methods for optimizing the scheduling of integrated electric-hydrogen power stations involve mathematically modeling the station's operational characteristics and constraints, transforming these characteristics and constraints into a mathematical model. Then, by applying piecewise linearization, duality theory, or KKT conditions, the mathematical model is transformed into a convex optimization problem, such as linear optimization or second-order cone optimization, with the objective function of maximizing economic efficiency, thus deriving a scheduling scheme for the integrated electric-hydrogen power station.

[0005] However, according to the "Regulations on the Safety Management of Hazardous Chemicals," hydrogen is classified as a hazardous chemical due to its flammable and explosive properties. Therefore, in the scheduling optimization process of an integrated electric-hydrogen station, it is necessary to verify the practical feasibility of the derived scheduling scheme from a safety perspective. Because the temperature of the hydrogen tank changes significantly during rapid filling and discharging, a scheduling scheme that only considers economic optimization is often insufficient for practical use in the scheduling plan of an integrated electric-hydrogen station. Summary of the Invention

[0006] The purpose of this invention is to propose a safe operation method for an integrated electric-hydrogen station that takes into account the temperature changes of the hydrogen tank. Considering the temperature changes during the filling and discharging process of the hydrogen tank, the method indirectly constrains the temperature of the hydrogen tank through an iterative algorithm for correcting the filling and discharging speed of the hydrogen tank, and derives a scheduling scheme that is practically feasible and results in less loss of benefits.

[0007] To achieve the above objectives, the technical solution of the present invention is: a method for safe operation of an integrated electric-hydrogen station considering temperature changes in the hydrogen tank, comprising the following steps:

[0008] S1. By performing Monte Carlo simulation on the probability density function of the arrival time of the vehicles being served, the load curve of the integrated electric-hydrogen station is obtained.

[0009] S2. Establish mathematical programming models for each component inside the integrated electric-hydrogen station;

[0010] S3. Input the parameters of each part into the model and use the commercial software gurobi to perform the first relaxation solution.

[0011] S4. Based on the temperature change results, add net velocity and constraints to the model;

[0012] S5. Solve the model again after adding constraints;

[0013] S6. Determine if the temperature is within the safe range. If it is not within the safe range, return to step S4. If it is within the safe range or the maximum number of iterations has been reached, proceed to step S7.

[0014] S7. Obtain a scheduling plan for the safe operation of the hydrogen storage tank in the integrated electric-hydrogen station.

[0015] Preferably, the mathematical programming models for establishing the various components inside the integrated electric-hydrogen station include an electrolyzer model, a long-tube trailer hydrogen transportation model, a hydrogen storage tank model, a fuel cell model, a cooling refueling gun, and a compressor model.

[0016] Preferably, the electrolytic cell model is specifically:

[0017]

[0018] In the formula, It is the power of the electrolytic cell at time t. It is a 0-1 variable for controlling the start and stop of the electrolytic cell, P e,max It is the maximum power of the electrolytic cell, ΔP e It is the maximum power change per unit time. This refers to the amount of hydrogen produced by the electrolyzer per unit time. It is the low calorific value of hydrogen. The efficiency of the electrolyzer is represented by Δt, which represents the efficiency per unit time. T is an intermediate variable used to prevent frequent start-stop operations. e,stamin T represents the minimum stop time of the electrolytic cell. e,stomin Indicates the minimum start-up time of the electrolytic cell. This represents a 0-1 variable that controls the start and stop of the electrolytic cell;

[0019] The long-tube trailer hydrogen transport model is specifically as follows:

[0020]

[0021] Formula (1.2) contains constraints on the hydrogen unloading rate, hydrogen loading rate, and hydrogen charging rate. These are control variables used to control the loading, unloading, and inflation of the long-tube trailer itself. These represent the loading, unloading, and inflation speeds, respectively, V. ttl,max V ttu,max V ttc,max These are the maximum values ​​for loading, unloading, and inflation speeds, respectively.

[0022]

[0023] M represents loaded hydrogen and purged hydrogen. ttc,min M ttc,max M represents the maximum and minimum values ​​of the charged hydrogen gas, respectively. ttl,max M ttl,min These represent the maximum and minimum values ​​of the loaded hydrogen gas, respectively.

[0024]

[0025] Formula (1.4) is the loading time constraint, T ttl It is the loading time, which is determined by the speed of the long-tube trailer and the distance from the chemical plant to the integrated electric-hydrogen station; It is an intermediate variable;

[0026] The hydrogen storage tank model is specifically as follows:

[0027]

[0028] M tank,min M tank,max These are the maximum and minimum masses that the hydrogen tank can hold. Let V be the mass of hydrogen in the hydrogen storage tank at time t. tank,max The maximum rate at which hydrogen is released or filled into the hydrogen storage tank. The rate at which hydrogen is released or filled into the hydrogen storage tank at time t;

[0029] The fuel cell model is specifically as follows:

[0030]

[0031] η is the power generated by the fuel cell at time t. fc It refers to fuel cell efficiency, P. fc,max This is the maximum power of the fuel cell, ΔP fc This is the maximum ramp power of the fuel cell. It is a 0-1 control variable;

[0032] The cooling injection gun and compressor models are specifically as follows:

[0033]

[0034] It is the compressor's power, P ref P atm These are the reference pressure and atmospheric pressure, respectively, ΔE cool To add the power required for cooling to the unit, Let be the mass of hydrogen gas added at time t. Let P be the mass of hydrogen that the hydrogen transport vehicle puts into the hydrogen storage tank at time t. op It is the operating pressure of the hydrogen tank. This is the power required for pre-cooling during hydrogen refueling.

[0035] Preferably, the hydrogen energy balance equations between the mathematical programming models of the various components inside the integrated electric-hydrogen power station are as follows:

[0036]

[0037] Let be the mass of hydrogen produced by the electrolyzer at time t. Let N be the speed at which the j-th hydrogen transport vehicle inputs hydrogen into the hydrogen storage tank at time t. tt For the number of hydrogen transport vehicles, Let N be the hydrogen refueling speed of the k-th fuel cell electric bus FCEB at time t. FCEB This represents the total number of fuel cell electric buses. The rate at which hydrogen is released or filled into the hydrogen storage tank at time t. Let be the refueling speed of the j-th hydrogen transport vehicle at time t. Let N be the hydrogen refueling speed of the m-th fuel cell vehicle (FCV) at time t. FCV For the total number of fuel cell vehicles, This represents the amount of hydrogen consumed by the fuel cell at time t.

[0038] Preferably, the energy balance equations between the various components within the integrated electric-hydrogen power station are as follows:

[0039]

[0040] P t BEV,l The charging power of the l-th battery electric vehicle at time t, N BEV P represents the total number of battery-powered electric vehicles. t EB,s The charging power of the s-th battery-electric bus at time t, N EB This represents the total number of battery-powered electric buses. Let be the photovoltaic power generation at time t. Let t be the power purchased from the grid.

[0041] Where P t BEV,l The binding condition is:

[0042] P t BEV,l ≤U t BEV,l P t BEV,l,max

[0043]

[0044] In the formula, U t BEV,l P is a 0-1 control variable. t BEV,l,max Let t be the maximum power of the l-th BEV.

[0045] Preferably, steps S4-S6 specifically include:

[0046] Step a: Let time i = 1; obtain the hydrogen mass in the hydrogen storage tank and the hydrogen release or filling rate of the hydrogen storage tank at N time points obtained from solving the integrated electric-hydrogen station model.

[0047] Step b: Based on the hydrogen mass in the hydrogen storage tank at time i and the rate at which hydrogen is released or filled into the hydrogen storage tank at time i Given the previous hydrogen storage tank temperature, calculate the hydrogen storage tank temperature T at time i. i ;

[0048] Step c, determine T i Does it meet the requirements? in, These are the preset maximum and minimum values ​​of the hydrogen storage tank temperature at time i; if they are satisfied, proceed to step d; otherwise, proceed to step e.

[0049] Step d: Determine if i satisfies i≤N; if it does, let i = i+1 and return to step b; otherwise, end the current process and proceed to S7.

[0050] Step e: Add net velocity and constraints to the integrated electric-hydrogen station model, and then determine whether the current iteration number q satisfies q≤Tter. max Among them, Tter max The maximum number of iterations is given, and the initial value of the current iteration number q is 1. If this condition is met, step f is executed; otherwise, the current process ends and proceeds to S7.

[0051] Step f: Let q = q + 1, solve the combined electric-hydrogen station model with added constraints again, and return to step a.

[0052] Preferably, the hydrogen storage tank temperature T at time i is calculated. i Specifically:

[0053]

[0054] In the formula, α and τ are both intermediate variables; T i-1 T is the temperature of the hydrogen storage tank at time i-1. When i=1, T0 is the initial temperature; T I / o T is the hydrogen charge / discharge temperature. a β is the ambient temperature; β is an intermediate constant. This represents the net hydrogen charging / discharging rate, used to substitute the rate at which hydrogen is released from or charged into the hydrogen storage tank at time i. Let be the mass of hydrogen gas, used to substitute the mass of hydrogen gas in the hydrogen storage tank at time i. a in A is the heat transfer coefficient between the inner wall of the hydrogen tank and the hydrogen gas. in It is the heat exchange area of ​​the inner wall of the hydrogen tank; c v For constant volume specific heat capacity, c p This is the specific heat capacity under constant pressure.

[0055] Preferably, the addition of net velocity and constraints to the integrated electric-hydrogen station model specifically involves:

[0056] like Then add constraints: The sum of the hydrogen release or inflow rates from the hydrogen tank at all times before time i in the next iteration should be greater than the sum of the hydrogen release or inflow rates from the hydrogen tank at all times before time i in the current iteration and the step size Δv.

[0057] like Then add constraints: The sum of the hydrogen release or inflow rates from the hydrogen tank at all times before time i in the next iteration should be less than the difference between the sum of the hydrogen release or inflow rates from the hydrogen tank at all times before time i in the current iteration and the step size Δv.

[0058] Preferably, the objective function is to minimize the total operating cost C of the EHRS on a daily timescale, which is determined by the electricity cost C. E Hydrogen cost and labor costs C lab It consists of three parts:

[0059]

[0060] Preferably, the electricity cost C E Hydrogen cost and labor costs C lab The calculation is as follows

[0061] C E =C grid -p EV (4.2)

[0062]

[0063]

[0064] In the formula, C grid The cost of electricity for purchasing electrolyzers and charging vehicles for EHRS, p EV Profits from electric vehicle charging services; C Hpri The cost of purchasing hydrogen from a chemical plant, p FCV Profit from FCV-charged services; The total number of charges for FCEBs and EBs during the night, t starting from a specific time point during the night, β' is the cost coefficient of the charging activity, and C tt-lab For the labor cost of long-tube trailers, C night-lab Labor costs for nighttime toll collection activities; λ gird , λ EV , λ FCV These are the prices for purchasing electricity from the grid, charging EVs, purchasing hydrogen from hydrogen production stations, and refueling FCVs.

[0065] Compared with the prior art, the present invention has the following beneficial effects:

[0066] This invention considers the safety hazards caused by temperature changes during the hydrogen tank filling and discharging process in the scheduling scheme. By establishing a thermodynamic zone one model of the hydrogen tank, the temperature of the filling and discharging process is calculated. An iterative method is used to sum the filling and discharging rates at the first time t to calculate the net rate. Constraining this rate and sum indirectly constrains the temperature of the hydrogen tank. This results in a more practical and feasible scheduling scheme with less loss of benefits, effectively improving the safety of the integrated electric-hydrogen station operation. Attached Figure Description

[0067] Figure 1Add a constraint flowchart for the iteration of this invention;

[0068] Figure 2 This is a diagram showing the station status of the FCEB and EB timetables in one embodiment of the present invention;

[0069] Figure 3 The hydrogen tank temperature change curve was not considered in the optimization process;

[0070] Figure 4 The hydrogen temperature change curve is considered to optimize the process. Detailed Implementation

[0071] The following is in conjunction with the appendix Figure 1-4 The technical solution of the present invention will be described in detail below.

[0072] This invention proposes a method for the safe operation of an integrated electric-hydrogen station considering temperature changes in the hydrogen tank, specifically including the following steps:

[0073] S1. By performing Monte Carlo simulation on the probability density function of the arrival time of the vehicles being served, the load curve of the integrated electric-hydrogen station is obtained.

[0074] S2. Establish mathematical programming models for each component inside the integrated electric-hydrogen station;

[0075] S3. Input the parameters of each part into the model and use the commercial software gurobi to perform the first relaxation solution.

[0076] S4. Based on the temperature change results, add net velocity and constraints to the model;

[0077] S5. Solve the model again after adding constraints;

[0078] S6. Determine if the temperature is within the safe range. If it is not within the safe range, return to step S4. If it is within the safe range or the maximum number of iterations has been reached, proceed to step S7.

[0079] S7. Obtain a scheduling plan for the safe operation of the hydrogen storage tank in the integrated electric-hydrogen station.

[0080] In this embodiment, the serviced vehicles include fuel cell electric buses (FCEB), fuel cell vehicles (FCV), electric vehicles (EV), and electric buses (EB).

[0081] The bus timetable is designed to minimize the average wear and tear on all buses, resulting in a schedule of bus stops. During the operating hours, the bus company adjusts the departure intervals based on varying passenger flow at different times. Taking the FCEB and EB timetables as examples, peak, mid-hour, and bottom-of-hour times are as follows: Figure 2As shown, the departure intervals are 5 minutes, 10 minutes, and 15 minutes. It is assumed that the buses strictly adhere to the operating schedule, with fixed travel time and energy consumption for each departure. To ensure consistent wear and tear on each bus, the operating tasks are evenly distributed among them. Their adherence to the timetable and station status are as follows: Figure 2 .

[0082] Based on data from the U.S. Department of Transportation's National Household Travel Survey (NHTS), fitting analysis revealed that initial charging time and driving distance follow a normal distribution as follows:

[0083]

[0084] f s (t), f D (s) represent the initial charging time and the driving distance, respectively. μ s μ D , σ s , σ D represents the fixed parameters after fitting, and represents a constant.

[0085] State of charge (SOC) is determined by driving distance, energy consumption per mile, and battery capacity during driving. Based on these distributions, the Monte Carlo method is used to generate charging data for electric taxis. Here, we consider private electric vehicles and electric taxis at stations. For fuel cell vehicles, the data is based on actual hydrogen load data from Shanghai HRS.

[0086] In this embodiment, the mathematical programming models for each component inside the integrated electric-hydrogen station are established, including the electrolyzer model, the long-tube trailer hydrogen transportation model, the hydrogen storage tank model, the fuel cell model, the cooling refueling gun, and the compressor model, as detailed below.

[0087] In this embodiment, the electrolytic cell model is specifically as follows:

[0088]

[0089] In the formula, It is the power of the electrolytic cell at time t. It is a 0-1 variable for controlling the start and stop of the electrolytic cell, P e,max It is the maximum power of the electrolytic cell, ΔP e It is the maximum power change per unit time. LHV is the amount of hydrogen produced by the electrolyzer per unit time. H2 It is the low calorific value of hydrogen. The efficiency of the electrolyzer is represented by Δt, which represents the efficiency per unit time. T is an intermediate variable used to prevent frequent start-stop operations. e,stamin T represents the minimum stop time of the electrolytic cell.e,stomin Indicates the minimum start-up time of the electrolytic cell. This represents a 0-1 variable that controls the start and stop of the electrolytic cell;

[0090] The long-tube trailer hydrogen transport model is specifically as follows:

[0091]

[0092] Formula (1.2) contains constraints on the hydrogen unloading rate, hydrogen loading rate, and hydrogen charging rate. These are control variables used to control the loading, unloading, and inflation of the long-tube trailer itself. These represent the loading, unloading, and inflation speeds, respectively, V. ttl,max V ttu,max V ttc,max These are the maximum values ​​for loading, unloading, and inflation speeds, respectively.

[0093]

[0094] M represents loaded hydrogen and purged hydrogen. ttc,min M ttc,max M represents the maximum and minimum values ​​of the charged hydrogen gas, respectively. ttl,max M ttl,min These represent the maximum and minimum values ​​of the loaded hydrogen gas, respectively.

[0095]

[0096] Formula (1.4) is the loading time constraint, T ttl It is the loading time, which is determined by the speed of the long-tube trailer and the distance from the chemical plant to the integrated electric-hydrogen station; It is an intermediate variable;

[0097] The hydrogen storage tank model is specifically as follows:

[0098]

[0099] M tank,min M tank,max These are the maximum and minimum masses that the hydrogen tank can hold. Let V be the mass of hydrogen in the hydrogen storage tank at time t. tank,max The maximum rate at which hydrogen is released or filled into the hydrogen storage tank. The rate at which hydrogen is released or filled into the hydrogen storage tank at time t;

[0100] The fuel cell model is specifically as follows:

[0101]

[0102] η is the power generated by the fuel cell at time t. fc It refers to fuel cell efficiency, P. fc,max This is the maximum power of the fuel cell, ΔP fc This is the maximum ramp power of the fuel cell. It is a 0-1 control variable;

[0103] The cooling injection gun and compressor models are specifically as follows:

[0104]

[0105] It is the compressor's power, P ref P atm These are the reference pressure and atmospheric pressure, respectively, ΔE cool To add the power required for cooling to the unit, Let be the mass of hydrogen gas added at time t. Let P be the mass of hydrogen that the hydrogen transport vehicle puts into the hydrogen storage tank at time t. op It is the operating pressure of the hydrogen tank. This is the power required for pre-cooling during hydrogen refueling.

[0106] In this embodiment, the hydrogen energy balance equations between the mathematical programming models of the various components inside the integrated electric-hydrogen station are as follows:

[0107]

[0108] Let be the mass of hydrogen produced by the electrolyzer at time t. Let N be the speed at which the j-th hydrogen transport vehicle inputs hydrogen into the hydrogen storage tank at time t. tt For the number of hydrogen transport vehicles, Let N be the hydrogen refueling speed of the k-th fuel cell electric bus FCEB at time t. FCEB This represents the total number of fuel cell electric buses. The rate at which hydrogen is released or filled into the hydrogen storage tank at time t. Let be the refueling speed of the j-th hydrogen transport vehicle at time t. Let N be the hydrogen refueling speed of the m-th fuel cell vehicle (FCV) at time t. FCV For the total number of fuel cell vehicles, This represents the amount of hydrogen consumed by the fuel cell at time t.

[0109] In this embodiment, the energy balance equations between the mathematical programming models of the various components inside the integrated electric-hydrogen power station are as follows:

[0110]

[0111] P t BEV,lThe charging power of the l-th battery electric vehicle at time t, N BEV P represents the total number of battery-powered electric vehicles. t EB,s The charging power of the s-th battery-electric bus at time t, N EB This represents the total number of battery-powered electric buses. Let be the photovoltaic power generation at time t. Let t be the power purchased from the grid.

[0112] Where P t BEV,l The binding condition is:

[0113] P t BEV,l ≤U t BEV,l P t BEV,l,max

[0114]

[0115] In the formula, U t BEV,l P is a 0-1 control variable. t BEV,l,max Let t be the maximum power of the l-th BEV.

[0116] In this embodiment, as Figure 1 Steps S4-S6 are specifically as follows:

[0117] Step a: Let time i = 1; obtain the hydrogen mass in the hydrogen storage tank and the hydrogen release or filling rate of the hydrogen storage tank at N time points obtained from solving the integrated electric-hydrogen station model.

[0118] Step b: Based on the hydrogen mass in the hydrogen storage tank at time i and the rate at which hydrogen is released or filled into the hydrogen storage tank at time i Given the previous hydrogen storage tank temperature, calculate the hydrogen storage tank temperature T at time i. i ;

[0119] Step c, determine T i Does it meet the requirements? in, These are the preset maximum and minimum values ​​of the hydrogen storage tank temperature at time i; if they are satisfied, proceed to step d; otherwise, proceed to step e.

[0120] Step d: Determine if i satisfies i≤N; if it does, let i = i+1 and return to step b; otherwise, end the current process and proceed to S7.

[0121] Step e: Add net velocity and constraints to the integrated electric-hydrogen station model, and then determine whether the current iteration number q satisfies q≤Tter.max Among them, Tter max The maximum number of iterations is given, and the initial value of the current iteration number q is 1. If this condition is met, step f is executed; otherwise, the current process ends and proceeds to S7.

[0122] Step f: Let q = q + 1, solve the combined electric-hydrogen station model with added constraints again, and return to step a.

[0123] In this embodiment, the hydrogen storage tank temperature T at time i is calculated. i Specifically:

[0124]

[0125] In the formula, α and τ are both intermediate variables; T i-1 T is the temperature of the hydrogen storage tank at time i-1. When i=1, T0 is the initial temperature; T I / o T is the hydrogen charge / discharge temperature. a β is the ambient temperature; β is an intermediate constant. This represents the net hydrogen charging / discharging rate, used to substitute the rate at which hydrogen is released from or charged into the hydrogen storage tank at time i. Let be the mass of hydrogen gas, used to substitute the mass of hydrogen gas in the hydrogen storage tank at time i. a in A is the heat transfer coefficient between the inner wall of the hydrogen tank and the hydrogen gas. in It is the heat exchange area of ​​the inner wall of the hydrogen tank; c v For constant volume specific heat capacity, c p This is the specific heat capacity under constant pressure.

[0126] In this embodiment, the addition of net velocity and constraints to the integrated electric-hydrogen station model specifically refers to:

[0127] like Then add constraints: The sum of the hydrogen release or inflow rates from the hydrogen tank at all times before time i in the next iteration should be greater than the sum of the hydrogen release or inflow rates from the hydrogen tank at all times before time i in the current iteration and the step size Δv.

[0128] like Then add constraints: The sum of the hydrogen release or inflow rates from the hydrogen tank at all times before time i in the next iteration should be less than the difference between the sum of the hydrogen release or inflow rates from the hydrogen tank at all times before time i in the current iteration and the step size Δv.

[0129] In this embodiment, the objective function is to minimize the total operating cost C of the EHRS on a daily timescale, which is determined by the electricity cost C. E Hydrogen cost and labor costs C lab It consists of three parts:

[0130]

[0131] In this embodiment, the electricity cost C E Hydrogen cost and labor costs C lab The calculation is as follows

[0132] C E =C grid -p EV (4.2)

[0133]

[0134]

[0135] In the formula, C grid The cost of electricity for purchasing electrolyzers and charging vehicles for EHRS, p EV Profits from electric vehicle charging services; C Hpri The cost of purchasing hydrogen from a chemical plant, p FCV Profit from FCV-charged services; The total number of charges for FCEBs and EBs during the night, t starting from a specific time point during the night, β' is the cost coefficient of the charging activity, and C tt-lab For the labor cost of long-tube trailers, C night-lab Labor costs for nighttime toll collection activities; λ gird , λ EV , λ FCV These are the prices for purchasing electricity from the grid, charging EVs, purchasing hydrogen from hydrogen production stations, and refueling FCVs.

[0136] The above are preferred embodiments of the present invention. Any changes made to the technical solution of the present invention that do not exceed the scope of the technical solution of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for the safe operation of an integrated electric-hydrogen station considering temperature changes in the hydrogen tank, characterized in that, Includes the following steps: S1. By performing Monte Carlo simulation on the probability density function of the arrival time of the vehicles being served, the load curve of the integrated electric-hydrogen station is obtained. S2. Establish mathematical programming models for each component inside the integrated electric-hydrogen station; S3. Input the parameters of each part into the model and use the commercial software gurobi to perform the first relaxation solution. S4. Based on the temperature change results, add net velocity and constraints to the model; S5. Solve the model again after adding constraints; S6. Determine if the temperature is within the safe range. If it is not within the safe range, return to step S4. If it is within the safe range or the maximum number of iterations has been reached, proceed to step S7. S7. Obtain a scheduling plan for the safe operation of the hydrogen storage tank in the integrated electric-hydrogen station; The mathematical programming models for establishing the internal components of the integrated electric-hydrogen station include an electrolyzer model, a long-tube trailer hydrogen transportation model, a hydrogen storage tank model, a fuel cell model, a cooling refueling gun, and a compressor model. The electrolytic cell model is specifically as follows: In the formula, It is the power of the electrolytic cell at time t. It is a 0-1 variable for controlling the start and stop of the electrolytic cell, P e,max It is the maximum power of the electrolytic cell, ΔP e It is the maximum power change per unit time. This refers to the amount of hydrogen produced by the electrolyzer per unit time. It is the low calorific value of hydrogen. The efficiency of the electrolyzer is represented by Δt, which represents the efficiency per unit time. T is an intermediate variable used to prevent frequent start-stop operations. e,stamin T represents the minimum stop time of the electrolytic cell. e,stomin Indicates the minimum start-up time of the electrolytic cell. This represents a 0-1 variable that controls the start and stop of the electrolytic cell; The long-tube trailer hydrogen transport model is specifically as follows: Formula (1.2) contains constraints on the hydrogen unloading rate, hydrogen loading rate, and hydrogen charging rate. These are control variables used to control the loading, unloading, and inflation of the long-tube trailer itself. These represent the loading, unloading, and inflation speeds, respectively, V. ttl,max V ttu,max V ttc,max These are the maximum values ​​for loading, unloading, and inflation speeds, respectively. M represents loaded hydrogen and purged hydrogen. ttc,min M ttc,max M represents the maximum and minimum values ​​of the charged hydrogen gas, respectively. ttl,max M ttl,min These represent the maximum and minimum values ​​of the loaded hydrogen gas, respectively. Formula (1.4) is the loading time constraint, T ttl It is the loading time, which is determined by the speed of the long-tube trailer and the distance from the chemical plant to the integrated electric-hydrogen station; It is an intermediate variable; The hydrogen storage tank model is specifically as follows: M tank,min M tank,max These are the maximum and minimum masses that the hydrogen tank can hold. Let V be the mass of hydrogen in the hydrogen storage tank at time t. tank,max The maximum rate at which hydrogen is released or filled into the hydrogen storage tank. The rate at which hydrogen is released or filled into the hydrogen storage tank at time t; The fuel cell model is specifically as follows: η is the power generated by the fuel cell at time t. fc It refers to fuel cell efficiency, P. fc,max This is the maximum power of the fuel cell, ΔP fc This is the maximum ramp power of the fuel cell. It is a 0-1 control variable; The cooling injection gun and compressor models are specifically as follows: It is the compressor's power, P ref P atm These are the reference pressure and atmospheric pressure, respectively, ΔE cool To add the power required for cooling to the unit, Let be the mass of hydrogen gas added at time t. Let P be the mass of hydrogen that the hydrogen transport vehicle puts into the hydrogen storage tank at time t. op It is the operating pressure of the hydrogen tank. This is the power required for pre-cooling during hydrogen refueling.

2. The method for safe operation of an integrated electric-hydrogen station considering temperature changes in a hydrogen tank, as described in claim 1, is characterized in that... The hydrogen energy balance equations between the various components within the integrated electric-hydrogen power station are as follows: Let be the mass of hydrogen produced by the electrolyzer at time t. Let N be the speed at which the j-th hydrogen transport vehicle inputs hydrogen into the hydrogen storage tank at time t. tt For the number of hydrogen transport vehicles, Let N be the hydrogen refueling speed of the k-th fuel cell electric bus FCEB at time t. FCEB This represents the total number of fuel cell electric buses. The rate at which hydrogen is released or filled into the hydrogen storage tank at time t. Let be the refueling speed of the j-th hydrogen transport vehicle at time t. Let N be the hydrogen refueling speed of the m-th fuel cell vehicle (FCV) at time t. FCV For the total number of fuel cell vehicles, This represents the amount of hydrogen consumed by the fuel cell at time t.

3. The method for safe operation of an integrated electric-hydrogen station considering temperature changes in the hydrogen tank according to claim 1, characterized in that, The energy balance equations between the various components within the integrated electric-hydrogen power station are as follows: P t BEV,l The charging power of the l-th battery electric vehicle at time t, N BEV P represents the total number of battery-powered electric vehicles. t EB,s The charging power of the s-th battery-electric bus at time t, N EB This represents the total number of battery-powered electric buses. Let be the photovoltaic power generation at time t. Let t be the power purchased from the grid. Where P t BEV,l The binding condition is: P t BEV,l ≤U t BEV,l P t BEV,l,max In the formula, U t BEV,l P is a 0-1 control variable. t BEV,l,max Let t be the maximum power of the l-th BEV.

4. The method for safe operation of an integrated electric-hydrogen station considering temperature changes in a hydrogen tank, as described in claim 1, is characterized in that... Steps S4-S6 are specifically as follows: Step a: Let time i = 1; obtain the hydrogen mass in the hydrogen storage tank and the hydrogen release or filling rate of the hydrogen storage tank at N time points obtained from solving the integrated electric-hydrogen station model. Step b: Based on the hydrogen mass in the hydrogen storage tank at time i and the rate at which hydrogen is released or filled into the hydrogen storage tank at time i Given the previous hydrogen storage tank temperature, calculate the hydrogen storage tank temperature T at time i. i ; Step c, determine T i Does it meet the requirements? in, These are the preset maximum and minimum values ​​of the hydrogen storage tank temperature at time i; if they are satisfied, proceed to step d; otherwise, proceed to step e. Step d: Determine if i satisfies i≤N; if it does, let i = i+1 and return to step b; otherwise, end the current process and proceed to S7. Step e: Add net velocity and constraints to the integrated electric-hydrogen station model, and then determine whether the current iteration number q satisfies q≤Tter. max Among them, Tter max The maximum number of iterations is given, and the initial value of the current iteration number q is 1. If this condition is met, step f is executed; otherwise, the current process ends and proceeds to S7. Step f: Let q = q + 1, solve the combined electric-hydrogen station model with added constraints again, and return to step a.

5. A method for safe operation of an integrated electric-hydrogen station considering temperature changes in a hydrogen tank, as described in claim 4, is characterized in that... The temperature T of the hydrogen storage tank at time i is calculated. i Specifically: In the formula, α and τ are both intermediate variables; T i-1 T is the temperature of the hydrogen storage tank at time i-1. When i=1, T0 is the initial temperature; T I / o T is the hydrogen charge / discharge temperature. a β is the ambient temperature; β is an intermediate constant. This represents the net hydrogen charging / discharging rate, used to substitute the rate at which hydrogen is released from or charged into the hydrogen storage tank at time i. Let be the mass of hydrogen gas, used to substitute the mass of hydrogen gas in the hydrogen storage tank at time i. a in A is the heat transfer coefficient between the inner wall of the hydrogen tank and the hydrogen gas. in It is the heat exchange area of ​​the inner wall of the hydrogen tank; c v For constant volume specific heat capacity, c p This is the specific heat capacity under constant pressure.

6. A method for safe operation of an integrated electric-hydrogen station considering temperature changes in a hydrogen tank, as described in claim 4, is characterized in that... The specific steps for adding net velocity and constraints to the integrated electric-hydrogen station model are as follows: like Then add constraints: The sum of the hydrogen release or inflow rates from the hydrogen tank at all times before time i in the next iteration should be greater than the sum of the hydrogen release or inflow rates from the hydrogen tank at all times before time i in the current iteration and the step size Δv. like Then add constraints: The sum of the hydrogen release or inflow rates from the hydrogen tank at all times before time i in the next iteration should be less than the difference between the sum of the hydrogen release or inflow rates from the hydrogen tank at all times before time i in the current iteration and the step size Δv.

7. A method for safe operation of an integrated electric-hydrogen station considering temperature changes in a hydrogen tank, as described in claim 2 or 3, characterized in that... The objective function is to minimize the total operating cost C of the EHRS on a daily timescale, determined by the electricity cost C. E Hydrogen cost and labor costs C lab It consists of three parts:

8. A method for safe operation of an integrated electric-hydrogen station considering temperature changes in a hydrogen tank, as described in claim 7, is characterized in that... The electricity cost C E Hydrogen cost and labor costs C lab The calculation is as follows C E =C grid -p EV (4.2) In the formula, C grid The cost of electricity for purchasing electrolyzers and charging vehicles for EHRS, p EV Profits from electric vehicle charging services; C Hpri The cost of purchasing hydrogen from a chemical plant, p FCV Profit from FCV-charged services; The total number of charges for FCEBs and EBs during the night, t starting from a specific time point during the night, β' is the cost coefficient of the charging activity, and C tt-lab For the labor cost of long-tube trailers, C night-lab Labor costs for nighttime toll collection activities; λ gird , λ EV , λ FCV These are the prices for purchasing electricity from the grid, charging EVs, purchasing hydrogen from hydrogen production stations, and refueling FCVs.

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