CN117639013A

CN117639013A - Wave energy power generation-based movable electric hydrogen energy supply platform optimizing energy supply method

Info

Publication number: CN117639013A
Application number: CN202311564573.2A
Authority: CN
Inventors: 赵露凡; 冯忠楠; 贺玮杰; 杨文豪; 魏繁荣
Original assignee: Huazhong University of Science and Technology
Current assignee: Huazhong University of Science and Technology
Priority date: 2023-11-22
Filing date: 2023-11-22
Publication date: 2024-03-01

Abstract

The invention relates to a movable electric hydrogen energy supply platform optimizing energy supply method based on wave energy power generation, which relates to the technical field of micro-grids. The specific scheme comprises the following steps: firstly, obtaining wave energy, a platform power side and data related to hydrogen production and storage, and establishing a platform model; then, establishing an optimization model by taking the benefit maximization as an objective function, and determining a system constraint condition; and finally, solving an objective function according to the electricity price and hydrogen price and wave energy fluctuation data, and continuously correcting and obtaining a final optimization scheme. The invention can fully utilize energy, reduce energy waste, obtain an optimal scheme in a specific scene and realize the maximization of benefits of the offshore movable energy supply platform.

Description

Wave energy power generation-based movable electric hydrogen energy supply platform optimizing energy supply method

Technical Field

The invention relates to the technical field of micro-grids, in particular to a movable electric hydrogen energy supply platform optimizing energy supply method based on wave energy power generation.

Background

Along with the increasing serious environmental pollution problem caused by the combustion of traditional fossil energy, the reserves of the fossil energy are smaller and smaller, and the energy utilization and environmental protection are important global issues. Under the current environmental protection and energy safety situations, the development of various new energy and renewable energy power generation has become necessary measures. Among them, renewable energy sources such as photovoltaic, wind power and waves have become a key power generation mode.

The ocean occupies about 71% of the earth, contains very rich resources, and has great utilization value and development space. Ocean energy includes tidal energy, tidal current energy, wave energy, temperature difference energy, salt difference energy, and the like. Ocean wave energy has received attention from many countries around the world as a renewable energy source with wide distribution, high energy density, no pollution and environmental friendliness.

Wave energy generates electricity off shore, and the larger the offshore distance is, the more wave energy resources are enriched. However, the offshore working conditions are severe, and even there are extreme weather such as hurricanes, tsunamis, etc., the further the offshore is, the more the safety problem, maintenance difficulty, etc. of the wave power generation device will be outstanding. And simultaneously, the submarine cable is high in cost and difficult to maintain, and the farther the submarine cable is off shore, the more difficult the energy transfer is. Therefore, the invention provides that the wave energy can be utilized to electrolyze seawater to prepare hydrogen for utilization. The hydrogen energy can compensate some problems encountered in the development and application of the wave energy power generation system. If the generated electricity is used to generate hydrogen, rather than delivering it to the coastline, then there is no need for extra long cables connecting the wave power generation system to the land line main grid. In addition, the generated hydrogen gas can be safely stored under water and kept at a low temperature at the bottom of the deep sea. The local storage of the generated energy also eliminates all cable-based energy transmission losses, further improving the efficiency of the overall system.

In recent years, hydrogen energy gradually enters the field of view of people as novel energy storage, and from the perspective of transportation cost, the hydrogen energy has the advantages of high energy density, high hydrogen storage density and no transportation loss, and the transportation cost of hydrogen is lower under the condition of transporting the same energy heating value; from the aspect of the electricity income, under the same electric quantity, the transmission in the form of hydrogen energy has larger economic benefit compared with the electric energy, and along with the great reduction of the hydrogen production cost, the transmission in the form of hydrogen energy has higher economic benefit.

The consumption and hydrogen production efficiency of the battery and the randomness and fluctuation of new energy power generation are comprehensively considered, the consumption capability and economic benefit of renewable energy sources can be effectively improved by adopting a mixed energy transmission mode of combining electric energy and hydrogen energy, and the produced electric energy is converted into the hydrogen energy or stored in a storage battery at a proper moment. The capacity configuration optimization method of the micro-grid taking the electric hydrogen coupling into consideration aims at utilization efficiency and economic operation, and the economic efficiency and the electric energy utilization rate of the self-operation mode of the micro-grid are verified through calculation examples. Compared with submarine cables or by means of storage batteries for energy transfer, the storage and transportation of hydrogen energy are more flexible, the storage and transportation of hydrogen energy are not limited by the charge and discharge power and the service life of the storage batteries, the mutual combination and utilization of hydrogen energy and electric energy become the trend of energy development in the future, and the hydrogen energy not only enriches the storage mode of renewable energy sources, but also promotes the diversification of energy structures.

Therefore, research on hybrid energy storage of wave energy and hydrogen energy is needed, and the research has great scientific and practical significance. The research can solve the problem of the absorption caused by the impact of wave energy power generation and improve the absorption capacity of renewable energy sources. The economy and the practicability of the wave energy power generation system are improved, the cost is reduced by the hydrogen production through the electrolysis of seawater, and the energy storage is realized. The method can promote the diversification of renewable energy sources and the transformation of energy source structures, enrich storage modes and promote the development of clean energy sources. In conclusion, research on hybrid energy storage of wave energy and hydrogen energy is significant for sustainable energy utilization, environmental protection and energy safety.

Disclosure of Invention

In order to solve the problems, the invention provides an optimized energy supply method of a movable electric hydrogen energy supply platform based on wave energy power generation. The influence of electricity price and hydrogen price fluctuation, load fluctuation and wave energy power generation uncertainty factors on the operation of the micro-grid can be comprehensively considered, and a scheme for maximizing the benefits of the platform is obtained through optimization.

The specific scheme of the invention is as follows:

a movable electric hydrogen energy supply platform optimizing energy supply method based on wave energy power generation comprises the following steps:

step 1, a movable electric hydrogen energy supply platform model based on wave energy driving is established, wherein the movable electric hydrogen energy supply platform based on wave energy driving comprises a wave energy power generation device, an engine, a storage battery, an electrolytic tank, a fuel cell, a heating rod, a compressor and a hydrogen storage tank;

the wave energy power generation device is used for generating wave energy, and the generated power is used for selling output electric energy, producing hydrogen through electrolysis and charging a storage battery through a direct current bus, and meanwhile the storage battery also has the function of stabilizing the voltage of the direct current bus; after the heating rod and the electrolytic tank are used for producing hydrogen through electrolysis, the hydrogen is stored in a hydrogen storage tank through a compressor, the hydrogen storage tank is used for outputting hydrogen energy to sell or conveying the hydrogen to a fuel cell, the fuel cell is used for reacting the hydrogen with oxygen to generate electric energy and water, the energy requirement of a platform is provided, and an engine is used for driving the platform to integrally move;

step 2, determining a model objective function as follows:

in the method, in the process of the invention,the hydrogen load demand is t time period;Is the hydrogen price at each moment; p (P) _din Is the amount of electricity required in the t period;Is the electricity price at each moment; k (k) ₁ Is the maintenance cost coefficient of the accumulator loss; k (k) ₂ Is the loss maintenance cost coefficient of the hydrogen electrolysis equipment; p (P) _com Is the engine power; k (k) ₃ Is the maintenance cost coefficient of the engine consumption, P _ch Charging power of accumulator, P _dis The method comprises the steps of (1) discharging power of a storage battery and determining a model constraint condition;

and 3, determining the required quantity and the required electric quantity of the hydrogen load at each moment based on the electric-hydrogen hybrid energy supply platform model driven by wave energy with the benefit f being maximized as a target, and selling the movable electric-hydrogen energy supply platform according to the required quantity and the required electric quantity of the hydrogen load at each moment under the constraint of constraint conditions.

Further, the movable electric hydrogen energy supply platform based on wave energy drive can be moored in open sea to capture wave energy resources and can also be moored in coastal ports to supply electric loads and hydrogen loads into land micro-networks; in the berthing state, the movable electric hydrogen energy supply platform can capture wave kinetic energy and potential energy, and the wave kinetic energy and the potential energy are stored in the storage battery in an electric energy mode or in the hydrogen storage tank in a hydrogen energy mode; in a moving state, the power generation device of the movable electric hydrogen energy supply platform is stored, power cannot be generated, and the moving platform is driven by power stored by a storage battery or power generated by a fuel cell.

Further, the movable electric hydrogen energy platform based on wave energy drive moves to the open sea shore in the low peak time of hydrogen price and electricity price to acquire more wave energy resources.

Further, the model constraint conditions in the step 2 are as follows:

E _WEG η _WEG +E _fc ＝E _ch -E _dis +P _ele T+P _com T+P _B T

E _ch ＝P _ch T

E _dis ＝P _dis T

wherein E is _WEG The wave energy value is; η (eta) _WEG The wave energy utilization efficiency is realized; e (E) _fc Powering the fuel cell by a number; e (E) _ch Charging the storage battery with energy consumption; e (E) _dis The storage battery is discharged to supply energy; p (P) _ele Energy is consumed for the electrolytic cell; t is the length of time; p (P) _com Energy is consumed for hydrogen compression; p (P) _B Energy is consumed for the heating rod;

E _RES ＝P _ele +H _B +H _fc

wherein P is _ele Is the electric energy needed in the electrolysis process; h _B 、H _fc The heat energy is respectively provided for the heating rod and the fuel cell in the electrolysis process; t (T) _S 、T ₀ Heating source temperature and ambient temperature, respectively;the energy required for heating the water; s is the cross-sectional area of the electrolytic cell; the temperature of electrolyte, wall surface and ambient air in the hydrogen production device is T _c 、T _w 、T ₀ ；C _c And C _w Is equivalent thermal capacitance in one direction, Z _c 、Z _w 、Z ₀ Respectively electrolyte, wall surface and environmental resistance; the peripheral wall node is connected to the external electrode through a thermal resistor (Z _c +Z _w (2) and (Z) ₀ +Z _w And/2) connected to the internal and external nodes to represent internal and external conduction/convection heat transfer characteristics; e (E) _RES Is controllable energy feedback;The amount of hydrogen produced for electrolysis of hydrogen; n (N) _c Is the number of electrolytic cells;Represents H ₂ Is a heat value of (2); i _c For passing an electrolyte current; u (u) _c Is the voltage across the cell.

After the technical scheme is adopted, compared with the prior art, the invention has the following advantages:

the electric energy flow, the hydrogen energy flow and the heat energy flow in the movable electric hydrogen energy supply platform based on wave energy drive are mutually coupled, and the energy flows in different forms can be effectively converted and allocated, so that unnecessary energy loss and waste are reduced, the energy utilization efficiency is improved, and the energy-saving and environment-friendly targets are realized; the dynamic flow coupling of energy has wide application prospect in the field of energy sources; the advantage of moving is that the platform can flexibly select the best wave energy resource point position and fully utilize rich wave energy resources. Through carrying out energy storage and hydrogen storage at the open sea shore, this platform can sell more energy at peak time, realizes profit maximize. And the mobile nature of the platform brings a more flexible, efficient and profit-rich mode of operation for the platform.

The invention will now be described in detail with reference to the drawings and examples.

Drawings

FIG. 1 is a flow chart of the invention in an embodiment of the invention;

FIG. 2 is a schematic diagram of a wave energy driven electro-hydrogen hybrid power platform model in which the black bold lines represent thermal energy flow, the dark gray represent hydrogen energy flow, and the light gray represent electrical energy flow according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of an oscillating hydraulic wave energy power plant in an embodiment of the invention;

FIG. 4 is a graph showing various output curves of wave energy after impact according to an embodiment of the present invention;

FIG. 5 is a graph showing the contradiction between the wave energy efficiency and the battery loss in the embodiment of the present invention;

FIG. 6 is a graph showing sales volume as a function of price in an embodiment of the present invention.

Detailed Description

The principles and features of the present invention are described below with reference to the drawings, the examples are illustrated for the purpose of illustrating the invention and are not to be construed as limiting the scope of the invention.

A movable electric hydrogen energy supply platform optimization strategy method based on wave energy power generation comprises the following steps:

step one: the method comprises the steps of obtaining wave energy, a platform power side and data related to hydrogen production and storage, and establishing a platform model, wherein the steps are as follows:

the specific steps for respectively establishing the component models are as follows:

firstly, establishing a platform integral model, wherein three energy flows of electricity, heat and hydrogen exist in the platform as shown in figure 2; in the figure, the black bold lines represent heat energy flows, the dark grey represents hydrogen energy flows, and the light grey represents electric energy flows. After wave energy generates electricity, the wave energy is used for hydrogen production by water electrolysis and battery charging through a direct current bus, and meanwhile, the battery also has the function of stabilizing the voltage of the direct current bus. The thermodynamic flow mainly exists in the hydrogen production system, and the generated heat of the fuel cell can be stored for hydrogen production and heat supply by water electrolysis, so that the thermodynamic waste is reduced. After hydrogen production by water electrolysis, the hydrogen is stored in a hydrogen storage tank through a compressor, and power is generated by a fuel cell at a proper moment.

We will divide the wave energy driven electro-hydrogen hybrid energy storage platform into three parts in the form of the main energy source. Firstly, electric energy flows, wherein the electric energy flows comprise electric energy generated by power generation of a wave energy device, electric energy charged and discharged by a storage battery, electric energy required to be consumed by electrolysis of an electrolytic tank, electric energy required to be consumed by movement of an engine driving platform, electric energy consumed by a heating rod, electric energy provided by a fuel cell and electric energy sold; secondly, hydrogen energy flow comprises hydrogen generated by hydrogen production, hydrogen consumed by hydrogen storage and hydrogen selling; finally, there is a flow of thermal energy, including the thermal energy of the heater rod, the thermal energy of the fuel cell, etc.

And (1.2) establishing a wave energy power generation model, as shown in fig. 3.

A basic schematic of a typical oscillating hydraulic wave energy generation system is shown in fig. 3. The system can be divided into three parts: capturing, storing and generating. The float captures wave energy and drives the hydraulic cylinder to output high-pressure oil to the accumulator, i.e. the wave energy is stored as hydraulic energy in the accumulator. When the hydraulic pressure builds up to a value that opens the valve, the control system opens the directional valve, driving the hydraulic motor and generator, thereby generating electricity.

The pressure of the energy is one of the main factors affecting the output electric power. If the wave resources are rich, the pressure of the accumulator is always at a relatively high level, so the system continues to generate electricity. However, if the wave is small, the pressure may drop to the closed valve pressure and the system stops generating electricity, presenting an intermittent feature. Thus, the wave energy output power curve will show different shapes for different opening valve pressures and wave energy resources.

The real-time value of the wave energy output can be described as follows:

where i is the wave energy output curve A, B, C mentioned below;is the actual wave energy power value at the moment t; p (P) _low Is the lowest power of wave energy; p (P) _op Is the power of wave energy at the opening valve pressure of the hydraulic control system; p (P) _c The power of the wave energy is the closing valve pressure of the hydraulic control system;Is the maximum power of wave energy; t (T) _wave Is the cumulative release period of wave energy; t (T) _r Is the release period of wave energy; t'. _r In the case of continuous power generation, the release is for a short time.

The accumulator pressure also affects the conversion efficiency of the wave energy power plant. The higher the accumulator pressure, the higher the energy collection efficiency of the wave energy. As shown in fig. 4, the accumulation period T is released _wave,i May vary with the output power curve, which makes it difficult to evaluate the performance of the different curves and does not match the fixed scheduling period of the microgrid. Therefore, a normalized generation model for different output curves of wave energy is needed.

Assume that n exists in the same scheduling period T _i The accumulation period is released. E (E) _wave,T Depending only on the wave energy source and the structure of the float, it is not affected by the modulation of the power curve. The mathematical description is as follows:

n _i T _wave,i ＝T

modulation time T _mod,i Is defined as assuming T-based release duty cycle and T-based _WEG,i Is consistent with the release duty cycle of (c).

In conjunction with the above, we can describe a normalized model of wave energy, regardless of the wave resource enrichment and release accumulation period.

Wherein eta _wave,i As a function of the output power of the wave energy. η (eta) _wave,i And P _op,i The relationship between these is shown in fig. 5, which is fitted according to experimental operation data.

Based on the normalized power generation model, it is apparent that the shape of the power curve can be easily changed by adjusting the device valve opening power, as shown by curves A, B and C in fig. 4. The opening pressure of curve a is the highest and therefore its impact characteristics are the most prominent.

Step (1.3) of establishing a hydrogen production and storage model

The hydrogen energy application platform comprises a hydrogen production part and a hydrogen storage part. The fuel cell is actually an electro-hydrogen coupling link, and from the viewpoint of energy supply, the fuel is capable of producing electricity, so the present invention divides it into electric energy application systems.

(1) Hydrogen production module model

(1) Working model

Aiming at the situation that the electrolytic tank consists of a plurality of electrolytic chambers connected in series, when the water electrolysis device carries out electrochemical reaction, the working voltage V at two ends of each electrolytic chamber _el Comprising a reversible voltage V _{rev_el} Activation overvoltage V _{act_el} And ohmic loss overvoltage V _{ohm_el} Three parts. The calculation formula is as follows:

V _el ＝V _{rev_el} +V _{act_el} +V _{ohm_el}

wherein: t (T) _el Is the working temperature of the electrolytic cell; the ideal gas constant is R; the Faraday constant is F; the ideal gas constant is R; the number of transferred electrons z (typically 2); current density i _el The method comprises the steps of carrying out a first treatment on the surface of the The exchange current densities of the cathode and the anode are respectively i _0,a And i _0,c The method comprises the steps of carrying out a first treatment on the surface of the The charge transport coefficients of the anode and cathode are alpha respectively _a And alpha _c ；δ _m Sum sigma _m Representing the film thickness and conductivity of the film.

P _el ＝N _el U _el I _el

η _el ＝m _el Q _{L_H2} /P _el

Wherein m is _el Hydrogen production rate for the electrolyzer; q (Q) _{L_H2} Is the heating value of the hydrogen.

(2) Efficiency characteristics

Wherein: η (eta) _el 、η _F And eta _V Respectively representing the system efficiency, faraday efficiency and voltage efficiency of the electrolytic cell; i _el Is the working current of the electrolytic cell; v (V) _th Is a thermal neutral voltage.

i _el ＝I _el /A _ele

Wherein A is _ele Is the effective area and Δs is the entropy.

The efficiency of the electrolytic cell is closely related to temperature and current density. When the current density is too low, the efficiency of the electrolytic cell is extremely low, and therefore, in order to improve the efficiency, it is preferable to operate in a high power (high efficiency) region, similarly to a fuel cell. When the current density increases to some extent, the system efficiency may drop slightly, since too high a degree of polarization consumes a lot of power. The temperature has less effect on the cell operating efficiency than the current density.

(2) Hydrogen storage module model

Wherein k and eta _com The polytropic coefficient and the compression efficiency, respectively.

The energy is also needed for compressing the hydrogen to the hydrogen storage tank, and the model formula is as follows

Wherein K is Kelvin; v (V) _sto The volume of the hydrogen storage tank; n is n _sto Is the amount of hydrogen in the hydrogen storage tank; a. b is a proportionality coefficient, a= 0.02476 Pa.m respectively ⁶ /mol，b＝2.661×10 ^-5 m ⁶ /mol；R _c Is an Avgalileo constant, 6.02X10 ²³ mol ^-1 ；n _el ，n _fc The hydrogen yield of the electrolytic tank and the hydrogen consumption of the fuel cell are respectively; n is n _re An initial hydrogen storage amount for the hydrogen storage tank. Sohc is the storage state of the hydrogen storage tank, P _N Is the maximum pressure.

In the method, in the process of the invention,the hydrogen capacity in the hydrogen storage device is t time intervals;Is the demand of hydrogen load in the t period.

In order to secure the safety of the hydrogen storage tank and the power generation efficiency of the fuel cell, the hydrogen storage system needs to limit the internal pressure. When hydrogen is stored, if the internal pressure is too high, hydrogen leakage and explosion danger can be caused, so that the safety of people is threatened. Therefore, the pressure in the hydrogen storage tank must be limited to ensure that it operates within a safe range. Meanwhile, too low a pressure also affects the power generation efficiency of the fuel cell, so that it is necessary to ensure that the pressure in the hydrogen storage tank is within a proper range.

Step (1.4), establishing a power side model;

(1) Storage model of storage battery

Batteries are a common energy storage device, and the system efficiency is critical to the operation and energy utilization efficiency of an electric power system. The system efficiency of the battery refers to the ratio of its actual output power to its input power, including the charge efficiency and discharge efficiency of the battery. And the system efficiency of the battery is affected by various factors including an open circuit voltage, an internal resistance, a charge-discharge current, and the like of the battery.

In designing and operating a battery energy storage system, multiple factors need to be comprehensively considered to improve system efficiency and reliability. For example, by optimizing the charge-discharge strategy and control algorithm of the battery, reducing the internal resistance of the battery, improving the stability of charge-discharge current, etc., the system efficiency of the battery can be effectively improved.

The model can be constructed as follows;

in the method, in the process of the invention,the electric energy stored at the moment t of the storage battery is used; sigma is the self-discharge coefficient of the accumulator, and 0.0046/d is taken;Charging power for storage battery t time,Discharging power for the storage battery t moment; soc is the state of charge of the battery; c (C) _bat For its rated capacity;And the charging and discharging efficiencies of the storage battery are respectively.

U _bat ＝f ₁ (SoC,I _bat )

Wherein: u (U) _bat Is the open circuit voltage of the battery; r is R _bat Is the internal resistance of the storage battery; i _bat Is the charge-discharge current of the storage battery. Wherein U is _bat And R is _bat And I _bat And the state of charge (Soc) of the battery.

(2) Fuel cell model

For simplicity of calculation, the irreversible loss of the fuel cell is regarded as an overpotential loss. The calculation formula of the Nernst voltage is as follows:

wherein E is _b The standard electromotive force is in a standard state (25 ℃ and 0.1 Mpa), 1.2n is the number of transferred electrons, and 2; f is Faraday constant; ΔS ₀ Is the molar entropy, 163.5J/(mol.K); t (T) _b Is at standard temperature, namely 298.15K;and->The pressure of oxygen and hydrogen, respectively.

U _fc,t ＝N _fc (E _n -U _act -U _ohm -U _conc )

Wherein U is _fc,t Is the fuel cell voltage; n (N) _fc Is the number of units connected in series; u (U) _act Is an active electrode overvoltage; u (U) _conc Is the concentration overpotential loss.

Wherein: i.e _fc Is of current density, A/cm ² ；ξ ₁ ＝-0.9514；A _fc Area of effective cell, cm ² ；ξ ₃ ＝7.4×10 ^-5 ；ξ ₄ ＝-1.87×10 ^-4 。

U _ohm ＝i _fc R _int

Wherein R is _int Is the internal resistance, omega/cm ² And takes a fixed value when the temperature is basically unchanged.

Concentration difference overvoltage loss U _conc Is caused by slow diffusion process, and the mathematical expression is that

I in _lim Is the limiting current.

In the method, in the process of the invention,is hydrogen molar mass, 2.02X10 ^-3 kg/mol；P _f,t Is the discharge power of the fuel cell at time t; q (Q) _fc,t Is the output power of the heat at time t;Is the amount of hydrogen gas input to the fuel cell; u (U) _fc,t And i is the output voltage and current of the fuel cell, respectively.

Pile efficiency eta _stack Fuel utilization rate eta _f And electrical efficiency eta _{E_fc} Multiplying to obtain combustionEfficiency of the material cell.

Wherein: p (P) _fc Output power for the fuel cell system; p (P) _stack Is pile power; v (V) _c Is the monolithic voltage of the fuel cell; e is related to the heat of reaction of the fuel cell stack.

As the output current increases, the polarization phenomenon causes the stack voltage to drop continuously, while the power of the fuel cell increases gradually, so that the system efficiency tends to increase and decrease. Furthermore, fuel cells operate at low power with low efficiency, so it is not desirable to operate in this power (efficiency) regime, as this will significantly affect their performance. Conversely, at high power, the system efficiency remains at a higher value, albeit at a reduced level.

The electric power obtained by the fuel cell from the hydrogen storage tank is P _fc The remaining power exists in the form of thermal energy.

P _fc ＝η _fc n _fc L _{HV_H2}

Wherein L is _{HV_H2} Is hydrogen with low heat value; n is n _fc The hydrogen rate is consumed for the fuel cell.

Step two: establishing an optimization model by taking the benefit maximization as an objective function, and determining a system constraint condition;

the establishment steps of the constraint condition of the multi-energy flow are specifically as follows:

step (2.1) determining constraints on the electrical energy flow according to its path

E _WEG η _WEG +E _fc ＝E _ch -E _dis +P _ele T _mod +P _com T _mod +P _B T _mod

In which the electric energy flow includes the energy generated by wave energy and the energy supplied by fuel cells. These electrical energy streams are used in various energy conversion and storage processes including battery charging and discharging, water electrolysis to produce hydrogen, compressed hydrogen, heating by heating rods, etc. In the processes, the conversion and the allocation of energy can realize multi-energy flow coupling, thereby improving the utilization efficiency of energy sources.

Step (2.2) determining the constraint conditions according to the hydrogen energy flow path

Wherein P is _ele Is the electric energy needed in the electrolysis process; h _B 、H _fc The heat energy is respectively provided for the heating rod and the fuel cell in the electrolysis process; t (T) _S 、T ₀ Heating source temperature and ambient temperature, respectively;the energy required for heating the water; s is the cross-sectional area of the electrolytic cell, m ² 。

Electrolytic water hydrogen production is a process of decomposing water into hydrogen and oxygen, which is then stored for subsequent energy requirements. Compressed hydrogen is compressed into a liquid or high pressure gas for storage and transportation. And the heating rod is used for heating water or air by recovering waste heat, so that the energy utilization efficiency is improved.

Step (2.3) determining the constraint conditions of the heat energy flow according to the path of the heat energy flow

E _RES ＝P _ele +H _B +H _fc

The temperature of the electrolyte, the wall surface and the ambient air in the hydrogen production device isT _c 、T _w 、T ₀ With equivalent thermal capacitance C in one direction _c 、C _w And resistance Z _c 、Z _w 、Z ₀ The heat accumulation and heat exchange problems of the electrolyte and the peripheral wall are treated by a classical lumped parameter method. The peripheral wall node is connected to the external electrode through a thermal resistor (Z _c +Z _w (2) and (Z) ₀ +Z _w And/2) are connected to the internal and external nodes to represent internal and external conduction/convection heat transfer characteristics. The thermal interaction between the electrolyte, the wall and the ambient air can then be controlled by node analysis, where E _RES Is controllable energy feedback; n (N) _c In general, an electrolyzer stack should include a certain number N _c To ensure that there is enough H ₂ Yield;represents H ₂ Is a heat value of (2); i _c For passing an electrolyte current; u (u) _c Is the voltage across the cell.

Step three: determining an objective function comprising electricity and hydrogen price fluctuations:

in the middle ofIs the hydrogen price at each moment;The hydrogen sales amount at each moment;Is the electricity price at each moment; p (P) _din The sales power quantity at each moment; k (k) ₁ Is the maintenance cost coefficient of the accumulator loss; k (k) ₂ Is the loss maintenance cost coefficient of the hydrogen electrolysis equipment; p (P) _ele Is electrolysis power; k (k) ₃ Is the maintenance cost coefficient of the engine loss; p (P) _m Is the engine power.

In order to achieve maximum benefit of the mobile hydrogen-powered platform, several factors need to be considered in combination: electricity sales amount, hydrogen sales amount, battery loss, electrolysis loss, and engine loss. The electricity selling amount refers to the income obtained by supplying electric energy to external users, and is specifically the electricity selling amount P at different moments _din And electricity priceIs a product of (a) and (b). In order to maximize the amount of electricity sold, it is necessary to optimize the generation and supply processes of electric energy, ensuring stable output and efficient use of electric energy. This can be achieved by effectively managing and scheduling the power generation apparatus to provide more power during periods of high electricity prices or periods of high demand. The amount of hydrogen sales means income obtained by supplying the generated hydrogen gas to the external user, specifically means the amount of hydrogen sales per time +.>And hydrogen valence->Is a product of (a) and (b). Meanwhile, the energy supply platform has certain loss in the operation process, and certain funds are required to be invested for maintenance and repair. The battery loss refers to the loss due to energy conversion and storage in the charge and discharge process, and concretely refers to the maintenance coefficient k of the storage battery ₁ And charge and discharge power (P) _dis +P _ch ) Is a product of (a) and (b). The electrolysis loss refers to the loss in the electrolysis process of converting electric energy into hydrogen, and concretely refers to the loss maintenance cost coefficient k of the hydrogen electrolysis equipment ₂ With electrolytic power P _ele Is a product of (a) and (b). Engine losses refer to losses when power is generated using a hydrogen engine, specifically an engine maintenance factor k ₃ With engine power P _m Is a product of (a) and (b). These losses require that we invest in maintenance costs.

Step four: according to the hydrogen price electricity price fluctuation scene, corresponding operation requirements are generated, the objective function is solved, and the final optimization scheme is continuously corrected and obtained:

by taking the above factors into consideration, a movable electric hydrogen energy platform can achieve maximization of revenue. This will help to improve energy efficiency, reduce costs, and promote the development of renewable energy and hydrogen energy technologies.

The electrical energy stream, the hydrogen energy stream and the thermal energy stream are coupled to each other. Through the formula model, the energy flows in different forms can be effectively converted and allocated, so that unnecessary energy loss and waste are reduced, the energy utilization efficiency is improved, and the energy-saving and environment-friendly targets are realized. The dynamic flow coupling of energy has wide application prospect in the field of energy.

Examples

The embodiment of the invention provides a movable electric hydrogen energy platform optimization strategy method based on wave energy power generation, which combines wave energy resources and hydrogen price electricity price fluctuation data shown in table 1;

TABLE 1

The flow chart of the invention shown in fig. 1 comprises the following steps:

step 1, obtaining relevant wave energy data as shown, and establishing a platform model, wherein the steps are as follows:

with the objective of building a movable platform model as shown in fig. 2, the specific steps of building each component model are as follows:

step (1.1), establishing a wave energy power generation model,

the real-time value of the wave energy output can be described as follows:

in the case of a small wave, the wave,

n _i T _wave,i ＝T

step (1.2) of establishing a hydrogen production and storage model

(1) Hydrogen production module model

(1) Working model

The calculation formula is as follows:

V _el ＝V _{rev_el} +V _{act_el} +V _{ohm_el}

wherein: the number of transferred electrons z (usually 2).

P _el ＝N _el U _el I _el

η _el ＝m _el Q _{L_H2} /P _el

i _el ＝I _el /A _ele

The operating temperature of the cell was set at 75℃in this example.

(2) Hydrogen storage module model

Wherein a and b are proportionality coefficients, and a= 0.02476 Pa.m respectively ⁶ /mol，b＝2.661×10 ^-5 m ⁶ /mol；R _c Is an Avgalileo constant, 6.02X10 ²³ mol ^-1 。

Step (1.3) of establishing a power side model

(1) Storage model of storage battery

U _bat ＝f ₁ (SoC,I _bat )

(2) Fuel cell model

The calculation formula is as follows

U _fc,t ＝N _fc (E _n -U _act -U _ohm -U _conc )

U _ohm ＝i _fc R _int

P _fc ＝η _fc n _fc L _{HV_H2}

Where σ is the self-discharge coefficient of the battery, and 0.0046/d is taken. E (E) _b The standard electromotive force is 1.229V under the standard state (25 ℃ and 0.1 Mpa); n is the number of transferred electrons and is 2; f is a methodA pull-up constant; ΔS ₀ Is the molar entropy, 163.5J/(mol.K); t (T) _b Is at standard temperature, namely 298.15K; i.e _fc Is of current density, A/cm ² ；ξ ₁ ＝-0.9514；A _fc 5.23×10 as effective cell area ⁴ cm ² ；ξ ₃ ＝7.4×10 ^-5 ；ξ ₄ ＝-1.87×10 ^-4 。Is hydrogen molar mass, 2.02X10 ^-3 kg/mol。

Step 2, establishing a configuration optimization model by taking benefit maximization as an objective function, and determining system constraint conditions;

E _RES ＝P _ele +H _B +H _fc

In the hydrogen production device, the temperature of electrolyte, wall surface and ambient air is T _c 、T _w 、T ₀ With equivalent thermal capacitance C in one direction _c 、C _w And resistance Z _c 、Z _w 、Z ₀ Specific data thereof refer to table 2:

TABLE 2

Project	Parameters (parameters)
		Cc	625kJ/K
Cw	467kJ/K
		Zc	0.167K/W
Zw	1.659K/W
		Zo	2.149℃/W

Step 3, determining an objective function containing electricity price and hydrogen price fluctuation, which comprises the following steps

Wherein the maintenance coefficients thereof are as shown in the following Table 3:

TABLE 3 Table 3

Type(s)	Acquisition cost parameter
		Storage battery	1000 yuan/kWh
Fuel cell	10000 yuan/kW
		Electrolytic cell	18000 yuan/kW
Engine with a motor	26000 Yuan/kW

In order to achieve maximum benefit of the mobile hydrogen-powered platform, several factors need to be considered in combination: electricity sales amount, hydrogen sales amount, battery loss, electrolysis loss, and engine loss. And solving the objective function.

Step 4, knowing that wave energy resources of the sea area are shown in a table 1, inputting electricity prices and hydrogen prices at different moments are shown in a table 1, generating corresponding operation demands according to scenes, solving an objective function by utilizing an optimization function algorithm, continuously correcting and obtaining a final energy supply scheme, wherein in the diagram, pe is the electricity price, ph2 is the hydrogen price, pdin is the electricity sales amount, and it can be seen that the electricity sales amount is correspondingly higher when the electricity price is higher and the hydrogen sales amount is correspondingly higher when the hydrogen price is higher, so that larger profit can be obtained;

as shown in fig. 6, the embodiment of the present invention moves to the open sea shore at a time when the hydrogen price and the electricity price are low to obtain a richer wave energy resource. In particular, embodiments of the present invention provide for moving to the open coast from 0 to 4 am because the wave energy resources on the open coast are now more abundant.

At the offshore time from 0 to 4 am, the hydrogen and electric energy storage link is mainly carried out. The platform converts as much wave energy as possible into hydrogen and electricity and stores it. And then, when the platform returns to the shore, selling and distributing the profit maximization according to the fluctuation of the hydrogen price and the electricity price. Compared with the pure electricity selling, the case can store and sell more electric energy and hydrogen energy, so that richer profits are realized.

The advantage of moving is that the platform can flexibly select the best wave energy resource point position and fully utilize rich wave energy resources. Through carrying out energy storage and hydrogen storage at the open sea shore, this platform can sell more energy at peak time, realizes profit maximize. And the mobile nature of the platform brings a more flexible, efficient and profit-rich mode of operation for the platform.

The foregoing is illustrative of the best mode of carrying out the invention, and is not presented in any detail as is known to those of ordinary skill in the art. The protection scope of the invention is defined by the claims, and any equivalent transformation based on the technical teaching of the invention is also within the protection scope of the invention.

Claims

1. The wave energy power generation-based movable electric hydrogen energy supply platform optimizing energy supply method is characterized by comprising the following steps of:

step 2, determining a model objective function as follows:

2. The method for optimizing energy supply of a movable electro-hydrogen energy supply platform based on wave energy power generation according to claim 1, wherein the movable electro-hydrogen energy supply platform based on wave energy drive can be moored to open sea to capture wave energy resources and also to coastal ports to supply electric load and hydrogen load into land micro-nets; in the berthing state, the movable electric hydrogen energy supply platform can capture wave kinetic energy and potential energy, and the wave kinetic energy and the potential energy are stored in the storage battery in an electric energy mode or in the hydrogen storage tank in a hydrogen energy mode; in a moving state, the power generation device of the movable electric hydrogen energy supply platform is stored, power cannot be generated, and the moving platform is driven by power stored by a storage battery or power generated by a fuel cell.

3. The wave energy power generation-based movable electric hydrogen energy platform optimizing energy supply method according to claim 1, wherein the wave energy power generation-based movable electric hydrogen energy platform moves to the open sea shore in a low peak period of hydrogen price and electricity price to acquire more wave energy resources.

4. The method for optimizing energy supply of the movable electric hydrogen energy supply platform based on wave energy power generation according to claim 1, wherein the model constraint conditions in the step 2 are as follows:

E _WEG η _WEG +E _fc ＝E _ch -E _dis +P _ele T+P _com T+P _B T

E _ch ＝P _ch T

E _dis ＝P _dis T

E _RES ＝P _ele +H _B +H _fc