Modeling method and device for photovoltaic power generation hydrogen production and storage system

Abstract

The invention discloses a photovoltaic power generation hydrogen production and storage system modeling method and device, and belongs to the technical field of comprehensive energy systems. The method comprises the following steps: firstly, constructing a mathematical model of output electric energy of a photovoltaic cell assembly, then constructing a mathematical model of a proton exchange membrane stack, constructing an energy conservation equation of the proton exchange membrane stack, and when output voltage and current are equal to voltage and current in the mathematical model of the proton exchange membrane stack, determining that the energy conservation equation is equal to the output voltage and current. The photovoltaic power generation hydrogen production and storage system obtains electric energy from the photovoltaic battery assembly, and further obtains the hydrogen production amount and the oxygen production amount along with the change of the illumination intensity and the battery temperature. According to the method, a heat transfer and mass transfer balance equation considering illumination intensity and battery temperature change at the same time is established in a combined system of a photovoltaic power generation assembly and a hydrogen production and storage system for the first time, a light-electricity transportation, electrolytic hydrogen production reaction kinetics and heat transfer and mass transfer coupling mathematical model is established, and the energy consumption of the photovoltaic power generation assembly and the hydrogen production and storage system is reduced from the collaborative angle of operation regulation and control and heat energy utilization. Regulation and control characteristic research is carried out, and the influence of the heat and mass transfer process on the system is reflected.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of comprehensive energy systems, and particularly relates to a photovoltaic power generation hydrogen production and storage system modeling method and device. BACKGROUND

[0002] Large-scale consumption of fossil energy has led to a series of problems such as environmental pollution, climate change and resource shortage. Large-scale and efficient utilization and clean replacement of renewable energy are the key to solving the above problems and realizing low-carbon transformation. However, the bidirectional superposition of temporal instability of source-side wind energy and solar energy and the peak-valley fluctuation of terminal energy load makes the safe and stable operation of new power systems dominated by new energy face great challenges. The hydrogen production technology by water electrolysis based on renewable energy power can convert electrical energy into chemical energy, and is not limited by the Carnot cycle efficiency, has the advantages of high efficiency and no pollution, and can realize the storage and transmission of electrical energy, which is an effective way to solve the high proportion of renewable energy consumption in the future new energy system.

[0003] Hydrogen production by water electrolysis is to apply direct current in an electrolysis device with water as a reactant to produce hydrogen and oxygen. Although the solid oxide water electrolysis technology has low energy consumption and high efficiency, it requires high stability and corrosion resistance of materials due to its high operating temperature, and is currently still in the research and development stage. The traditional alkaline water electrolysis technology has the highest maturity, does not require noble metal catalysts, and has realized industrial scale application. However, it has low current density and poor adaptability to load changes. The proton exchange membrane water electrolysis technology has high current density and strong flexibility, and has good adaptability to renewable energy.

[0004] The energy transmission process of the photovoltaic power generation hydrogen production and storage system is not only affected by unstable fluctuation of solar radiation or heat flow input, but also faces cross-scale structure coupling between different components, which aggravates the instability of the operation process. Therefore, the membrane material is seriously degraded, the system operation cost is increased, and the system safety is reduced. SUMMARY

[0005] The purpose of the present application is to overcome the shortcomings of the prior art, and to provide a photovoltaic power generation hydrogen production and storage system modeling method and device to solve the problem of serious degradation of membrane material caused by instability of the operation process in the coupling process of the structure between different components in the prior art.

[0006] To achieve the above purpose, the following technical scheme is adopted: A photovoltaic power generation hydrogen production and storage system modeling method, comprising the following steps: Collecting output current and output voltage of a single photovoltaic cell changing with light intensity and cell temperature, and obtaining output voltage and output current of a photovoltaic cell group based on the output current and output voltage of the single photovoltaic cell; The electrolysis voltage and electrolysis current in the single electrolytic cell are collected, and the total electrolysis voltage and total electrolysis current of the proton exchange membrane stack are further obtained; An energy conservation equation of the proton exchange membrane stack is established, which is related to output electric energy of the photovoltaic cell group, energy of inlet water, chemical energy of output hydrogen, heat of output hydrogen, heat of output oxygen, heat of output water and heat loss of the hydrogen production and storage system; When the output voltage is equal to the total electrolysis voltage, and the output current is equal to the total electrolysis current, the hydrogen production and storage system obtains electric energy from the photovoltaic cell group, and obtains hydrogen production and oxygen production under the current light intensity and cell temperature based on the energy conservation equation of the proton exchange membrane stack.

[0007] Further improvement of the present application is that: Preferably, the output current is:

[0008] In the formula: V is the output voltage, V; I ph is the photocurrent, A; I sat is the saturation current, A; N s is the number of series units; e is the cell ideal factor; R s is the series resistance, Ω; R sh is the parallel resistance, Ω.

[0009] Preferably, the output voltage and output current of the photovoltaic cell group are:

[0010]

[0011] In the formula: N s is the number of series photovoltaic cells; N p is the number of parallel photovoltaic cells, V is the output voltage, I is the output current.

[0012] Preferably, the input electric energy of the stack is The calculation formula is:

[0013] wherein, is the total electrolysis voltage of the proton exchange membrane stack, is the total electrolysis current.

[0014] The total voltage and total current of the electrolysis of the proton exchange membrane stack are preferably calculated according to the following formula:

[0015]

[0016] wherein: n is the number of electrolysis cells inside the proton exchange membrane stack; A is the effective area of the proton exchange membrane of the electrolysis cell, cm 2 , i is the current density, A / cm 2 .

[0017] The electrolysis voltage of the individual electrolysis cell is preferably calculated according to the following formula:

[0018] wherein: V ocv is the open circuit voltage, V; η act is the activation overpotential, V; η ohm is the ohmic overpotential, V.

[0019] The energy conservation equation of the proton exchange membrane stack is preferably calculated according to the following formula:

[0020] wherein: ΔrH is the standard molar enthalpy of formation, J / mol; N H2O,in is the water flow rate at the inlet of the stack, mol / s; N H2 is the hydrogen flow rate, mol / s; N O2 is the oxygen flow rate, mol / s; N H2O,out is the water flow rate at the outlet of the stack, mol / s; C p,H2O is the specific heat capacity of water, J / mol·K; C p,H2 is the specific heat capacity of hydrogen, J / mol·K; C p,O2 is the specific heat capacity of oxygen, J / mol·K; T in is the water temperature at the inlet of the stack, K; T 0 is the reference temperature, taken as 298.15 K; Q loss is the heat exchanged between the stack and the environment, W.

[0021] Preferably, the hydrogen production amount is calculated by the following formula:

[0022] wherein, I 总 is the total electrolysis current, n is the number of electrolytic cells in the proton exchange membrane stack.

[0023] Preferably, the oxygen production amount is calculated by the following formula:

[0024] wherein, I 总 is the total electrolysis current, n is the number of electrolytic cells in the proton exchange membrane stack.

[0025] A photovoltaic power generation hydrogen production and storage system modeling device, comprising: a photovoltaic unit for collecting the output current and output voltage of a single photovoltaic cell changing with the light intensity and the cell temperature, and obtaining the output voltage and output current of the photovoltaic cell group based on the output current and output voltage of the single photovoltaic cell; a hydrogen production unit for collecting the electrolysis voltage and electrolysis current in a single electrolytic cell, and further obtaining the total electrolysis voltage and total electrolysis current of the proton exchange membrane stack; a balance unit for establishing an energy conservation equation of the proton exchange membrane stack, the energy conservation equation being related to the output electrical energy of the photovoltaic cell group, the energy of the inlet water, the chemical energy of the output hydrogen, the heat of the output hydrogen, the heat of the output oxygen, the heat of the output water, and the heat loss of the hydrogen production and storage system; an output unit for the hydrogen production and storage system to obtain electrical energy from the photovoltaic cell group when the output voltage is equal to the total electrolysis voltage, and the output current and the total electrolysis current are equal, and for the output unit to obtain the hydrogen production amount and the oxygen production amount under the current light intensity and cell temperature based on the energy conservation equation of the proton exchange membrane stack.

[0026] Compared with the prior art, the present application has the following beneficial effects: The application discloses a photovoltaic power generation hydrogen production and storage system modeling method, which comprises a photovoltaic cell group, a proton exchange membrane stack and a hydrogen storage system modeling process. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 A photovoltaic power generation hydrogen production and storage system schematic diagram is provided in the application. 1, photovoltaic cell group; 2, proton exchange membrane stack; 3, oxygen side gas-water separator; 4, hydrogen side gas-water separator; 5, first heat exchanger; 6, second heat exchanger; 7, third heat exchanger; 8, first dryer; 9, second dryer; 10, oxygen storage tank; 11, water supplement tank; 12, hydrogen storage tank. DETAILED DESCRIPTION

[0028] Hereinafter, the terms "first", "second", "third", "fourth" are only used for description purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined with "first", "second", "third", "fourth" can explicitly or implicitly include one or more of the features.

[0029] The method of shooting provided by the embodiments of the application can be applied to terminal devices such as mobile phones, tablet computers, wearable devices, vehicle-mounted devices, augmented reality (AR) / virtual reality (VR) devices, notebook computers, ultra-mobile personal computers (UMPC), netbooks, personal digital assistants (PDA), and the like. The embodiments of the application do not make any limitation on the specific type of terminal device.

[0030] It should be noted that the terms "first", "second", and the like in the description and in the claims of the present application are used for distinguishing between similar objects and not necessarily for describing a specific sequential or chronological order. It is to be understood that the use of such terms is interchangeable under appropriate circumstances such that the embodiments of the application described herein are, for example, capable of orderly or inverse order. Furthermore, the terms "comprise", "comprising", "include", "including", and the like are intended to cover non-exclusive inclusions, such that a process, method, system, product, or apparatus that comprises a list of steps or units are not necessarily limited to those steps or units, but can include other steps or units not expressly listed or inherent to such process, method, product, or apparatus.

[0031] Referring to Figure 1 The photovoltaic power generation hydrogen production and storage system is a core component of the photovoltaic power generation hydrogen production and storage system, which comprises a photovoltaic cell group 1, a proton exchange membrane stack 2, a gas-water separator, a heat exchanger, a dryer, and a storage tank.

[0032] The photovoltaic cell group 1 provides power for the proton exchange membrane stack 2, water in the proton exchange membrane stack 2 is decomposed to generate hydrogen and oxygen, the hydrogen outlet of the proton exchange membrane stack 2 is connected with the hydrogen side gas-water separator 12, the oxygen outlet is connected with the oxygen side gas-water separator 3, the gas outlet of the oxygen side gas-water separator 3 is communicated with the hot side pipeline inlet of the first heat exchanger 5, the hot side pipeline outlet of the first heat exchanger 5 is communicated with the first dryer 8, the outlet of the first dryer 8 is communicated with the oxygen storage tank 10, the outlet of the hydrogen side gas-water separator 3 is communicated with the hot side pipeline inlet of the third heat exchanger 7, the hot side pipeline outlet of the third heat exchanger 7 is communicated with the second dryer 9, the outlet of the second dryer 9 is communicated with the hydrogen storage tank 12; the outlet of the water tank 11, the water outlet of the oxygen side gas-water separator 3, and the water outlet of the hydrogen side gas-water separator 4 are all communicated with the hot side pipeline of the second heat exchanger 6, and the cold side pipelines of the first heat exchanger 5, the second heat exchanger 6, and the third heat exchanger 7 are all communicated with cooling water.

[0033] The working principle of the present application: the solar cell of the system converts solar energy into electrical energy and supplies the proton exchange membrane stack 2. The proton exchange membrane stack 2 electrolyzes water under the driving of electrical energy to produce hydrogen and oxygen. The generated gas is separated by the gas-water separator, and the gas is cooled by the first heat exchanger 5 and the third heat exchanger 7, and after drying by the dryer, it is stored in the oxygen storage tank 10 and the hydrogen storage tank 12. The separated water and the water supplement are mixed and then flow into the second heat exchanger 6 for heat exchange, and then flow into the proton exchange membrane stack 2. The cooling water is heated by the heat exchanger, and the quality is improved. The thermal energy can be used for energy cascade utilization in the form of heating electrolytic water supply or heating. When the light intensity changes, the operation of the proton exchange membrane stack fluctuates. By adjusting the operating parameters (inlet water temperature and inlet flow) of the proton exchange membrane stack, the heat and mass transfer process inside the stack can be improved, the electrochemical reaction can be promoted, and the hydrogen production of the system can be improved. During the operation of the system, the cooling water is heated by the heat exchanger, and the quality is improved. The thermal energy can be used for energy cascade utilization in the form of heating electrolytic water supply or heating.

[0034] For the above system, a photovoltaic power generation hydrogen production and storage system modeling method of the present application comprises the following steps: S1, collecting the output current and output voltage of the individual photovoltaic cell with the change of light intensity and cell temperature, obtaining the output voltage and output current of the photovoltaic cell group based on the output current and output voltage of the individual photovoltaic cell; S2, collecting the electrolysis voltage and electrolysis current in the individual electrolytic cell, and further obtaining the total electrolysis voltage and total electrolysis current of the proton exchange membrane stack; S3, establishing the energy conservation equation of the proton exchange membrane stack, which is related to the output electrical energy of the photovoltaic cell group, the energy of the inlet water, the chemical energy of the output hydrogen, the heat of the output hydrogen, the heat of the output oxygen, the heat of the output water, and the heat loss of the hydrogen production and storage system; S4, when the output voltage is equal to the total electrolysis voltage, and the output current is equal to the total electrolysis current, the hydrogen production and storage system obtains electrical energy from the photovoltaic cell group, and based on the energy conservation equation of the proton exchange membrane stack, the hydrogen production and oxygen production under the current light intensity and cell temperature are obtained.

[0035] In some embodiments of the present application, in S1, the specific process of constructing the mathematical model of the photovoltaic cell assembly is: The output current of the photovoltaic cell I can be represented as:

[0036] In the formula: V is the output voltage, V; I ph is the photocurrent, A; I satIsatfor the saturation current, A; N s N is the number of cells in series, with a value of 72; e Z is the battery ideality factor; R s Rs is the series resistance, Ω; R sh Rp is the parallel resistance, Ω.

[0037] Th is the thermal voltage V th Isc can be expressed as:

[0038] where: k k is the Boltzmann constant, 1.3806 x 10 -23 J / K; T T is the battery temperature, K; q e is the electronic charge, 1.6022 x 10 -19 C.

[0039] Isc is the short circuit current I ph Isat is the saturation current I sat Voc can be expressed as:

[0040]

[0041] where: I sc Isc is the short circuit current, A; V oc Voc is the open circuit voltage, V.

[0042] Isc is the short circuit current of the photovoltaic cell I sc Voc is the open circuit voltage V oc Rs is the series resistance R s Rp is the parallel resistance R sh Z is the battery ideality factor e In actual cases will vary with the intensity of the light G and the battery temperature T cell T. The battery temperature T cell is related to the intensity of the light G and the air temperature T air T, and can be expressed as:

[0043] where:T cell,0 The battery temperature measured at 800 W / m 2 , 293.15 K and wind speed 1 m / s.

[0044] When the battery temperature T cell , the light intensity G , the series resistance R s , the parallel resistance R sh , the battery ideality factor e , the open circuit voltage V oc , the short circuit current I sc may be expressed as:

[0045]

[0046]

[0047]

[0048]

[0049] where: T cell，ref Tref is the reference battery temperature, K; G ref Iref is the reference light intensity, W / m 2 ; e ref nref is the reference battery ideality factor; V oc，ref Vref is the reference open circuit voltage, V; I sc，ref Iscref is the reference short circuit current, A; R s，ref Rserf is the reference series resistance, Ω; R sh，ref Rparef is the reference parallel resistance, Ω.

[0050] A certain number of photovoltaic cells are combined in series or in parallel to form a photovoltaic cell group. If the photovoltaic cells in the photovoltaic cell group have the same technical parameters, its voltage is related to the number of series, and the current is related to the number of parallel. The voltage V arr , the current I arr may be expressed as:

[0051]

[0052] wherein: N s is the number of series of photovoltaic cells; N p is the number of parallel of photovoltaic cells.

[0053] Solar energy input of photovoltaic power generation hydrogen production and hydrogen storage system Q sol may be expressed as:

[0054] wherein: A sol is the total area of photovoltaic cell panel, m 2 ; T sun is the solar surface temperature, taking the value of 5600 K; T 0 is the ambient temperature, taking the value of 298.15 K.

[0055] In some embodiments of the present application, in S2, the process of establishing a mathematical model of a proton exchange membrane stack is as follows: Taking a proton exchange membrane electrolyzer as the research object, the voltage thereof is composed of reversible potential and overpotential. In the overpotential, the diffusion overpotential is much smaller than the ohmic overpotential and the activation overpotential, so the diffusion overpotential can be ignored. The electrolysis voltage V cell may be expressed as:

[0056] wherein: V ocv is the open circuit voltage, V; η act is the activation overpotential, V; η ohm is the ohmic overpotential, V.

[0057] Open circuit voltage V ocv is the minimum potential difference required for hydrogen production by water electrolysis, which is calculated by the Nernst equation, and may be expressed as:

[0058] wherein: P H2 is the hydrogen partial pressure at the cathode, Pa; P O2 is the oxygen partial pressure at the anode, Pa; a H2O is the activity of water, taking the value of 1; T is the stack operating temperature, K; V 0 is the reversible potential under standard pressure. The reversible potentialV 0 can be expressed as:

[0059] activation overpotential η act is the potential loss of the electrochemical reaction in the process of water electrolysis to produce hydrogen, which is calculated by the Butler-Volmer equation, and can be expressed as:

[0060] wherein: α an is the anode charge transfer coefficient; α cat is the cathode charge transfer coefficient; i is the current density, A / cm 2 ; i 0,an is the anode exchange current density, A / cm 2 ; i 0,cat is the cathode exchange current density, A / cm 2 .

[0061] ohmic overpotential η ohm is the potential loss of the electrochemical reaction in the electrolytic cell due to the current passing through the electrode. It is calculated by Ohm's law, and can be expressed as:

[0062] wherein: δ m is the proton exchange membrane thickness, μm; σ m is the proton exchange membrane conductivity, S / m.

[0063] proton exchange membrane conductivity σ m can be expressed as:

[0064] wherein: λ is the water content of the proton exchange membrane.

[0065] total electrolysis voltage of the proton exchange membrane stack V stack , total electrolysis current I 总 can be expressed as:

[0066]

[0067] wherein: nThe number of cells in the proton exchange membrane stack; A The effective area of the proton exchange membrane of the cell, cm 2 .

[0068] The electrical energy input into the stack can be expressed as:

[0069] In some embodiments of the present application, the energy conservation equation of the proton exchange membrane stack in S3 can be expressed as:

[0070] In the above energy conservation equation, the first term on the left side of the energy conservation equation is the electrical energy input into the stack, and the second term is the energy of the inlet water; on the right side of the equation, the first term is the chemical energy contained in the hydrogen, the second term is the heat of the outlet hydrogen, the third term is the heat of the outlet oxygen, the fourth term is the heat of the outlet water, and the fifth term is the heat loss of the system. In the energy conservation equation, the input energy and the output energy through the entire system are balanced, and the electrical energy, chemical energy, heat, and loss of the system are all taken into account.

[0071] In the formula: ΔrH is the standard molar enthalpy of formation, J / mol; N H2O,in is the flow rate of the inlet water of the stack, mol / s; N H2 is the flow rate of the hydrogen, mol / s; N O2 is the flow rate of the oxygen, mol / s; N H2O,out is the flow rate of the outlet water of the stack, mol / s; C p,H2O is the specific heat capacity of water, J / mol·K; C p,H2 is the specific heat capacity of hydrogen, J / mol·K; C p,O2 is the specific heat capacity of oxygen, J / mol·K; T in is the temperature of the inlet water of the stack, K; T 0 is the reference temperature, which is 298.15 K; Q loss is the heat exchanged between the stack and the environment, W; F is the Faraday constant.

[0072] The heat exchanged between the stack and the environment Q loss can be expressed as:

[0073] In the formula: R tFor the proton exchange membrane stack heat resistance, K / W.

[0074] In some embodiments of the present application, in S4, when the output electrical energy of the photovoltaic cell assembly is equal to the electrolysis electrical energy in the hydrogen production and storage system in S2, then the output electrical energy of the photovoltaic cell assembly is all used by the proton exchange membrane stack 2, at this time the hydrogen production and oxygen production when the light intensity and cell temperature change can be calculated.

[0075] Hydrogen flow generated by the stack N H2 Oxygen flow N O2 And the water flow consumed N H2O Can be expressed as:

[0076]

[0077] Stack outlet water flow N H2O,out Can be expressed as:

[0078] Taking the heat exchanger 2 as the research object, the mixed water of the stack outlet water and the makeup water is heat exchanged, and then flows into the stack as the stack inlet water. The energy conservation equation of the heat exchanger 2 is established, which can be expressed as:

[0079] In the formula: N H2O,sup The stack makeup water flow, which is equal to the water flow consumed by the stack, mol / s; H The enthalpy value of the substance, J / mol; Q ex The external heat, Q ex When the positive value indicates that the stack needs to be supplied with heat from the outside world, Q ex The negative value indicates that the stack needs to dissipate heat to the outside world, W.

[0080] Taking the heat exchangers 1 and 3 as the research object, the gas generated by the stack electrolysis water needs to be cooled before being stored. The energy conservation equation of the heat exchangers 1 and 3 is established, which can be expressed as:

[0081]

[0082] In the formula: N 1 is the heat exchanger 1 cooling water flow, mol / s; N3 is the cooling water flow rate of heat exchanger 3, mol / s; T 1 is the cooling water outlet temperature of heat exchanger 1, K; T 3 is the cooling water outlet temperature of heat exchanger 3, K. The end temperature difference is set to 5.0 K, that is, the difference between the inlet temperature of the hot fluid and the outlet temperature of the cold fluid.

[0083] The energy efficiency of the photovoltaic-proton exchange membrane electrolysis water hydrogen coupling system can be expressed as:

[0084]

[0085] In the formula: Q net LHV is the low heat value of hydrogen, For the hydrogen storage tank, the state equation can be written as:

[0086] In the formula: C p,H2 Cp is the specific heat capacity of hydrogen, the value is 14.233 kJ / (kg·K); W cp is the outlet gas flow rate, kg / s; k is the specific heat ratio of hydrogen at standard conditions, the value is 1.4; η cp is the compressor efficiency; P1 and P2 are the inlet and outlet pressures, respectively, MPa.

[0087] The second aspect of the present application discloses a photovoltaic power generation hydrogen production and storage system modeling device, comprising: A photovoltaic unit is used to collect the output current and output voltage of a single photovoltaic cell changing with light intensity and cell temperature, and to obtain the output voltage and output current of a photovoltaic cell group based on the output current and output voltage of the single photovoltaic cell; A hydrogen production unit is used to collect the electrolysis voltage and electrolysis current in a single electrolytic cell, and to further obtain the total electrolysis voltage and total electrolysis current of a proton exchange membrane stack; A balance unit is used to establish an energy conservation equation of the proton exchange membrane stack, which is related to the output electrical energy of the photovoltaic cell group, the energy of the inlet water, the chemical energy of the output hydrogen, the heat of the output hydrogen, the heat of the output oxygen, the heat of the output water, and the heat loss of the hydrogen production and storage system; An output unit is used to obtain the hydrogen production and oxygen production under the current light intensity and cell temperature based on the energy conservation equation of the proton exchange membrane stack when the output voltage is equal to the total electrolysis voltage, and the output current is equal to the total electrolysis current, so that the hydrogen production and storage system obtains electrical energy from the photovoltaic cell group.

[0088] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flow or blocks Figure 1 means for functionally implementing the steps in the flowchart block or blocks.

[0089] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instructions which implement the function specified in the flowchart block or blocks. Figure 1 one or more flow or blocks Figure 1 means for functionally implementing the steps in the flowchart block or blocks.

[0090] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flow or blocks Figure 1 means for functionally implementing the steps in the flowchart block or blocks.

[0091] Finally, it should be noted that the above-mentioned embodiments are merely intended to illustrate the technical solutions of the present application, but not to limit the present application. Although the present application has been described in detail with reference to the above-mentioned embodiments, those skilled in the art should understand that the technical solutions of the present application can still be modified or equivalent replaced without departing from the spirit and scope of the present application, and any modification or equivalent replacement should be included in the protection scope of the present application.

[0092] The above-mentioned embodiments are only intended to illustrate the technical solutions of the present application, but not to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A photovoltaic power generation hydrogen production and storage system modeling method, characterized in that: The following steps are involved: Collect the output current and output voltage of individual photovoltaic cells that change with light intensity and cell temperature, and obtain the output voltage and output current of the photovoltaic cell group based on the output current and output voltage of the individual photovoltaic cells; Collecting the electrolysis voltage and electrolysis current in a single electrolytic cell, and further obtaining the total electrolysis voltage and total electrolysis current of the proton exchange membrane stack; Establishing an energy conservation equation for the proton exchange membrane stack, which is related to the output electrical energy of the photovoltaic cell group, the energy of the inlet water, the chemical energy of the output hydrogen, the heat of the output hydrogen, the heat of the output oxygen, the heat of the output water, and the heat loss of the hydrogen production and storage system; When the output voltage is equal to the total electrolysis voltage, and the output current is equal to the total electrolysis current, the hydrogen production and storage system obtains electrical energy from the photovoltaic battery group, and obtains the hydrogen and oxygen production under the current light intensity and battery temperature based on the energy conservation equation of the proton exchange membrane stack.

2. A photovoltaic power generation hydrogen production and storage system modeling method according to claim 1, characterized in that: The output current is: Where: V is the output voltage, V; I ph is the photocurrent, A; I sat is the saturation current, A; N s is the number of units connected in series; e is the battery ideal factor; R s is the series resistance, Ω; R sh is the parallel resistance, Ω.

3. A photovoltaic power generation hydrogen production and storage system modeling method according to claim 1, characterized in that: The output voltage and output current of the photovoltaic cell group are: Where: N s is the number of photovoltaic cells connected in series; N p is the number of photovoltaic cells in parallel, V is the output voltage, I is the output current.

4. A photovoltaic power generation hydrogen production and storage system modeling method according to claim 1, characterized in that: Input power to the stack The calculation formula is: in, is the total electrolysis voltage of the proton exchange membrane stack, is the total electrolysis current.

5. A photovoltaic power generation hydrogen production and storage system modeling method according to claim 4, characterized in that: The calculation formulas for the total electrolysis voltage and total electrolysis current of the proton exchange membrane stack are: Where: n is the number of electrolyzers inside the proton exchange membrane stack; A is the effective area of ​​the proton exchange membrane of the electrolyzer, cm 2 , i is the current density, A / cm 2 .

6. A photovoltaic power generation hydrogen production and storage system modeling method according to claim 5, characterized in that: The calculation formula of the electrolysis voltage of the individual electrolytic cells is: Where: V ocv is the open circuit voltage, V; η act is the activation overpotential, V; η ohm is the ohmic overpotential, V.

7. A photovoltaic power generation hydrogen production and storage system modeling method according to claim 1, characterized in that: The energy conservation equation of the proton exchange membrane stack is: Where: ΔrH is the standard molar enthalpy of formation, J / mol; N H2O,in is the water flow rate at the stack inlet, mol / s; N H2 is the hydrogen flow rate, mol / s; N O2 is the oxygen flow rate, mol / s; N H2O,out is the water flow rate at the stack outlet, mol / s; C p,H2O is the specific heat capacity of water, J / mol·K; C p,H2 is the specific heat capacity of hydrogen, J / mol·K; C p,O2 is the specific heat capacity of oxygen, J / mol·K; T in is the stack inlet water temperature, K; T 0 is the base temperature, which is 298.15 K; Q loss is the heat exchanged between the battery stack and the environment, W.

8. A photovoltaic power generation hydrogen production and storage system modeling method according to claim 1, characterized in that: The calculation formula for the hydrogen production is: in, I 总 is the total electrolysis current, n is the number of electrolyzers inside the proton exchange membrane stack.

9. A photovoltaic power generation hydrogen production and storage system modeling method according to claim 1, characterized in that: The calculation formula of the oxygen production is: in, I 总 is the total electrolysis current, n is the number of electrolyzers inside the proton exchange membrane stack.

10. A photovoltaic power generation hydrogen production and storage system modeling device, characterized in that: include: A photovoltaic unit is used to collect the output current and output voltage of a single photovoltaic cell that changes with light intensity and cell temperature, and to obtain the output voltage and output current of the photovoltaic cell group based on the output current and output voltage of the single photovoltaic cell; The hydrogen production unit is used to collect the electrolysis voltage and electrolysis current in a single electrolyzer, and further obtain the total electrolysis voltage and total electrolysis current of the proton exchange membrane stack; A balancing unit is used to establish an energy conservation equation for the proton exchange membrane stack, wherein the energy conservation equation is related to the output electrical energy of the photovoltaic cell group, the energy of the inlet water, the chemical energy of the output hydrogen, the heat of the output hydrogen, the heat of the output oxygen, the heat of the output water, and the heat loss of the hydrogen production and storage system; The output unit is used to obtain electrical energy from the photovoltaic battery group when the output voltage is equal to the total electrolysis voltage and the output current is equal to the total electrolysis current, and obtain the hydrogen production and oxygen production under the current light intensity and battery temperature based on the energy conservation equation of the proton exchange membrane stack.

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