Electro-hydrogen-heat comprehensive energy system modeling method and system for low-carbon building

Abstract

The invention relates to the technical field of comprehensive energy systems, and particularly provides a low-carbon building-oriented electro-hydrogen-heat comprehensive energy system modeling method, which comprises the following steps of determining different physical fields involved in a low-carbon building-oriented electro-hydrogen-heat comprehensive energy system and mechanism models under each physical field, determining a model interface of each mechanism model; establishing a dynamic model of each component device according to each mechanism model; based on the dynamic model of each component device, establishing each subsystem model; and combining the sub-system models according to the model interfaces in the physical fields to obtain the low-carbon building-oriented electro-hydrogen-heat comprehensive energy system model. Therefore, on the basis of a modularized modeling thought, the modeling models are divided according to different fields, the coupling relation and the dynamic characteristics in the electro-hydrogen-heat comprehensive energy system can be accurately reflected, then the maintainability and the simulation efficiency of the models can be more effectively improved, and pre-judgment of dynamic changes of the system under different load conditions is helped.

Description

Technical Field

[0001] The present invention relates to the technical field of integrated energy systems, and in particular to a modeling method for an electric, hydrogen and heat integrated energy system for low-carbon buildings and a modeling system for an electric, hydrogen and heat integrated energy system for low-carbon buildings. Background Art

[0002] To achieve a green and sustainable supply of thermal power for buildings and avoid the problems of "backflow" and reverse overload of photovoltaic power generation in buildings, an electric, hydrogen and heat integrated energy system integrating photovoltaics, water electrolysis hydrogen production, hydrogen storage, hydrogen fuel cells, heat pump air conditioning, lithium batteries and system auxiliary equipment has become an effective solution for distributed energy supply for low-carbon buildings. The electric, hydrogen and heat integrated energy system for low-carbon buildings can effectively promote the consumption of renewable energy and balance supply and demand through hydrogen production and storage. Fuel cell cogeneration can improve the energy self-sufficiency rate of buildings and enhance the stability and dispatchability of the system. The electric, hydrogen and heat integrated energy system that integrates hydrogen production, storage and use is applied to the thermal power supply of buildings. It can achieve reversibility and interaction between electric and hydrogen, and is an important practice to solve the problems of carbon emission reduction in building energy consumption and future new energy consumption.

[0003] Integrated energy systems for low-carbon buildings involve hydrogen production, storage, and utilization, with related equipment and devices covering electricity, heat, gas, and other sectors. Traditional integrated energy system modeling focuses solely on internal system constraints and balances. These mathematical models tend to oversimplify system characteristics when dealing with complex multi-energy systems, resulting in insufficient accuracy in practical applications and an inability to accurately describe the coupling relationships and dynamic characteristics within the system. Summary of the Invention

[0004] In order to solve one of the above technical problems, the present invention proposes the following technical solution.

[0005] The first aspect of the present invention proposes a method for modeling an electric, hydrogen and heat integrated energy system for low-carbon buildings. The method includes the following steps: determining different physical fields involved in the electric, hydrogen and heat integrated energy system for low-carbon buildings and the mechanism models under each physical field, and determining the model interface of each mechanism model; establishing a dynamic model of each component equipment of the electric, hydrogen and heat integrated energy system according to the mechanism models under each physical field; establishing each subsystem model of the electric, hydrogen and heat integrated energy system based on the dynamic model of each component equipment; and combining the subsystem models according to the model interface to obtain the electric, hydrogen and heat integrated energy system model for low-carbon buildings.

[0006] In addition, the electric, hydrogen and heat integrated energy system modeling method for low-carbon buildings according to the above embodiment of the present invention may also have the following additional technical features.

[0007] According to one embodiment of the present invention, the physical field includes at least one of a fluid field, an electrical field, a thermal field, and a gas field.

[0008] According to one embodiment of the present invention, the mechanism model includes multiple types of physical process mechanism models, chemical process mechanism models and power process mechanism models.

[0009] According to one embodiment of the present invention, the model interface is a model interface based on the AMESim software platform.

[0010] According to one embodiment of the present invention, the various component equipment includes multiple types of pumps, compressors, heat exchangers, valves, pipelines, fuel cells, electrolytic cells, lithium batteries, photovoltaics, storage tanks and separation tanks.

[0011] According to one embodiment of the present invention, the subsystems include multiple types of power subsystem, thermal energy subsystem, hydrogen subsystem, photovoltaic subsystem, water electrolysis hydrogen production subsystem, hydrogen storage subsystem, fuel cell cogeneration subsystem and heat pump air conditioning subsystem.

[0012] The power subsystem is used for power transmission;

[0013] The thermal energy subsystem is used for thermal energy transmission;

[0014] The hydrogen subsystem is used for hydrogen transmission;

[0015] The photovoltaic subsystem is used for photovoltaic power generation;

[0016] The water electrolysis hydrogen production subsystem is used to perform water electrolysis based on the electrical energy provided by the photovoltaic subsystem to produce hydrogen and oxygen;

[0017] The hydrogen storage subsystem is used to store the hydrogen produced by the water electrolysis hydrogen production subsystem;

[0018] The fuel cell cogeneration subsystem is used to generate electricity and heat based on the hydrogen produced by the water electrolysis hydrogen production subsystem;

[0019] The heat pump air conditioning subsystem is used to generate heat based on the electric energy provided by the photovoltaic subsystem and the fuel cell cogeneration subsystem;

[0020] The lithium battery is used to store the electrical energy provided by the photovoltaic subsystem and the fuel cell cogeneration subsystem.

[0021] According to one embodiment of the present invention, the photovoltaic subsystem, the water electrolysis hydrogen production subsystem, the fuel cell cogeneration subsystem, the heat pump air conditioning subsystem, and the lithium battery are respectively connected to the power subsystem; the fuel cell cogeneration subsystem and the heat pump air conditioning subsystem are respectively connected to the thermal energy subsystem; the water electrolysis hydrogen production subsystem, the hydrogen storage subsystem, and the fuel cell cogeneration subsystem are respectively connected to the hydrogen subsystem.

[0022] The second aspect of the present invention proposes an electric, hydrogen and heat integrated energy system modeling system for low-carbon buildings, including: a determination module for determining the different physical fields involved in the electric, hydrogen and heat integrated energy system for low-carbon buildings and the mechanism models under each physical field, and determining the model interface of each mechanism model; a first establishment module for establishing a dynamic model of each component equipment of the electric, hydrogen and heat integrated energy system according to the mechanism models under the physical fields; a second establishment module for establishing each subsystem model of the electric, hydrogen and heat integrated energy system based on the dynamic models of the each component equipment; a combination module for combining the subsystem models according to the model interface to obtain an electric, hydrogen and heat integrated energy system model for low-carbon buildings.

[0023] The technical solution of the embodiment of the present invention first determines the mechanism models and their model interfaces in different fields, establishes each dynamic model based on the mechanism modules, then establishes each subsystem model based on the dynamic models, and finally combines the subsystem models to form an overall model. Therefore, based on the modular modeling concept and the multi-scale dynamic modeling method based on interdisciplinary model integration and multi-physics field coupling, it can accurately reflect the coupling relationship and dynamic characteristics within the electric, hydrogen and heat integrated energy system, helping to predict the dynamic changes of the system under different load conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a flow chart of a method for modeling an electric, hydrogen and heat integrated energy system for low-carbon buildings according to an embodiment of the present invention.

[0025] Figure 2 Schematic diagram of modular modeling of an embodiment of the present invention.

[0026] Figure 3 This is a connection diagram of an electric, hydrogen and heat integrated energy system for low-carbon buildings according to an embodiment of the present invention.

[0027] Figure 4 This is a schematic diagram of a fuel cell cogeneration subsystem model according to an example of the present invention.

[0028] Figure 5 This is a schematic diagram of a heat pump air conditioning subsystem model according to an example of the present invention.

[0029] Figure 6AThis is an influence curve of the dynamic response characteristics of the voltage of a fuel cell subsystem under the condition of a dynamic current step of an example of the present invention.

[0030] Figure 6B This is an influence curve of the dynamic response characteristics of the fuel cell PEMFC power and heat production under the current dynamic step condition of an exemplary fuel cell subsystem of the present invention.

[0031] Figure 7A This is an influence curve of the dynamic response characteristics of the compressor outlet pressure of a heat pump air-conditioning subsystem according to an example of the present invention when the compressor speed steps.

[0032] Figure 7B This is an influence curve of the dynamic response characteristics of the system condenser heat exchange and evaporator heat exchange when the compressor speed steps in a heat pump air conditioning subsystem of an example of the present invention.

[0033] Figure 8 This is a structural block diagram of a low-carbon building electric-hydrogen-heat integrated energy system modeling system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0034] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0035] The present invention provides a modeling method for an electric, hydrogen and heat integrated energy system for low-carbon buildings, which realizes multi-field dynamic mechanism modeling, can accurately reflect the coupling relationship and dynamic characteristics within the electric, hydrogen and heat integrated energy system, and help predict the dynamic changes of the system under different load conditions.

[0036] Figure 1 This is a flow chart of a method for modeling an electric, hydrogen and heat integrated energy system for low-carbon buildings according to an embodiment of the present invention.

[0037] like Figure 1 As shown, the electric, hydrogen and heat integrated energy system modeling method for low-carbon buildings includes the following steps S1 to S4.

[0038] S1. Determine the different physical fields involved in the electric, hydrogen and heat integrated energy system for low-carbon buildings and the mechanism models under each physical field, and determine the model interface of each mechanism model.

[0039] The physical field includes at least one of a fluid field, an electrical field, a thermal field, and a gas field.

[0040] Among them, the mechanism models include various types of physical process mechanism models, chemical process mechanism models and power process mechanism models.

[0041] Specifically, the electric, hydrogen and heat integrated energy system can include a variety of different energy forms, and the different physical fields such as fluid, electricity, heat, gas, etc. can be determined according to the type of energy, and the mechanism model and model interface under each physical field can be determined, among which the model interface is a model interface based on the AMESim software platform.

[0042] S2. Establish dynamic models of various components and equipment of the electric, hydrogen and thermal integrated energy system based on the mechanism models in various physical fields.

[0043] Among them, the various components and equipment include pumps, compressors, heat exchangers, valves, pipes, fuel cells, electrolytic cells, lithium batteries, photovoltaics, storage tanks and separation tanks.

[0044] S3, based on the dynamic model of each component equipment, establish the subsystem models of the electric, hydrogen and heat integrated energy system.

[0045] Among them, each subsystem can be divided according to function, such as a power subsystem for power transmission, a thermal energy subsystem for thermal energy transmission, etc.

[0046] Specifically, the dynamic models of each component equipment can be integrated through a modular method, and based on the structure of each subsystem, the dynamic models of the corresponding component equipment can be connected according to the model interface to obtain the subsystem models of the electric, hydrogen and heat integrated energy system.

[0047] S4, combine the subsystem models according to the model interface to obtain an electric, hydrogen and heat integrated energy system model for low-carbon buildings.

[0048] Specifically, based on the connection mode between the subsystems, the subsystem models can be combined according to the model interface to obtain a simulation model of the electric, hydrogen and heat integrated energy system for low-carbon buildings.

[0049] In general, if Figure 2 As shown, the embodiment of the present invention is based on a modular modeling approach. First, mechanism models are established in different physical fields, such as physical process mechanism models, chemical process mechanism models, and power process mechanism models. Dynamic models of various component equipment are established based on the mechanism models. Then, subsystem models are established based on the dynamic models of various component equipment. Finally, the subsystem models are combined according to the model interface to obtain an overall simulation model of the system.

[0050] This embodiment of the present invention identifies the relevant physical domains and models, constructs dynamic models of component equipment, and integrates subsystem models into a system-level model, enabling comprehensive dynamic simulation of the electric, hydrogen, and heat integrated energy system. This provides a scientific basis for the design and management of low-carbon buildings. It accurately reflects the coupling relationships and dynamic characteristics within the electric, hydrogen, and heat integrated energy system, helping to predict system dynamic changes under different load conditions.

[0051] Therefore, the electric, hydrogen and heat integrated energy system modeling method for low-carbon buildings in the embodiment of the present invention is based on a modular modeling idea and divides the modeling models according to different fields. It can accurately reflect the coupling relationship and dynamic characteristics within the electric, hydrogen and heat integrated energy system, and help predict the dynamic changes of the system under different load conditions.

[0052] In one embodiment of the present invention, Figure 3 As shown, the subsystems include multiple types of power subsystem, thermal energy subsystem, hydrogen subsystem, photovoltaic subsystem, water electrolysis hydrogen production subsystem, hydrogen storage subsystem, fuel cell cogeneration subsystem and heat pump air conditioning subsystem.

[0053] Power subsystem, used for power transmission;

[0054] Thermal energy subsystem, used for thermal energy transmission;

[0055] A hydrogen subsystem, used for hydrogen transmission;

[0056] Photovoltaic subsystem, used for photovoltaic power generation;

[0057] The water electrolysis hydrogen production subsystem is used to electrolyze water based on the electricity provided by the photovoltaic subsystem to produce hydrogen and oxygen;

[0058] A hydrogen storage subsystem, used to store hydrogen produced by the water electrolysis hydrogen production subsystem;

[0059] A fuel cell cogeneration subsystem is used to generate electricity and heat based on the hydrogen produced by the water electrolysis hydrogen production subsystem;

[0060] A heat pump air conditioning subsystem is used to generate heat using the electricity provided by the photovoltaic subsystem and the fuel cell cogeneration subsystem;

[0061] Lithium batteries are used to store the electrical energy provided by the photovoltaic subsystem and the fuel cell cogeneration subsystem.

[0062] Further, refer to Figure 3 The photovoltaic subsystem, water electrolysis hydrogen production subsystem, fuel cell cogeneration subsystem, heat pump air conditioning subsystem, and lithium battery are respectively connected to the power subsystem; the fuel cell cogeneration subsystem and heat pump air conditioning subsystem are respectively connected to the thermal energy subsystem; the water electrolysis hydrogen production subsystem, hydrogen storage subsystem, and fuel cell cogeneration subsystem are respectively connected to the hydrogen subsystem.

[0063] In one embodiment, the dynamic model of the component equipment in step S2 is as follows:

[0064] Dynamic model of fuel cell:

[0065] The hydrogen reaction rate (mol / s) can be calculated by the following formula:

[0066]

[0067] Where N cell , I cell , A cell They represent the number, current and area of PEMFC (Proton Exchange Membrane Fuel Cell) cells, respectively. j is the current density, and F is the Faraday constant. Indicates the molar flow rate of hydrogen consumed in the reaction (mol / s).

[0068] PEMFC stack output voltage (V stack ) can be expressed as:

[0069] V stack =E cell N cell (2)

[0070] Where, E cell It represents the actual output voltage of PEMFC. Various voltage losses are inevitable during the working process of PEMFC due to reaction kinetic loss, ohmic resistance of proton membrane and electrode materials, depletion of catalyst layer concentration, etc.

[0071] This paper mainly considers the PEMFC activation loss (E act ), Ohmic loss (E ohm ), concentration loss (E conc ) three parts, establish the following voltage model:

[0072] E cell =E rev -E act -E ohm -E conc (3)

[0073] Among them, E rev represents the PEMFC Nernst voltage, which can be calculated by the Nernst equation:

[0074]

[0075] Where T is the PEMFC operating temperature, are the partial pressures of hydrogen and oxygen, respectively.

[0076] Activation loss E of PEMFC act It can be calculated by the Tafel model:

[0077]

[0078] Where R represents the ideal gas constant, T is the PEMFC operating temperature, α is the charge transfer coefficient, n is the charge number, j0 is the exchange current density, and j is the current density.

[0079] Ohmic loss E ohm It can be calculated by the following formula:

[0080] E ohm =I cell R m =I cell t m / σ m (6)

[0081] Where R m represents the specific resistance of the proton exchange membrane, t m represents the thickness of the PEMFC proton membrane, σ m It represents the membrane conductivity and can be obtained by the empirical formula:

[0082]

[0083] Where λ represents the water content of the proton membrane, which can be obtained from the water vapor activity a w calculate:

[0084]

[0085]

[0086] Among them, P w represents the partial pressure of water, P sat Indicates the saturated vapor pressure of water vapor.

[0087] PEMFC concentration loss E conc , which can be calculated using empirical values and empirical formulas:

[0088] E conc =-Bln(1-j / j L ) (10)

[0089] Where B represents the empirical coefficient, j L is the limiting current density.

[0090] In terms of mass balance, the hydrogen consumption can be obtained by formula (4), and the mass balance on the anode side can be expressed as:

[0091]

[0092] Where, Indicates the hydrogen consumption on the anode side, Indicates the water production on the anode side, n i,an,in and n i,an,out They represent the molar flow rates of the anode gas i (hydrogen, water vapor) flowing in and out, is the mass flow rate of water vapor transported across the membrane to the cathode.

[0093] The mass balance on the cathode side can be expressed as:

[0094]

[0095] Where, and They represent the oxygen consumed by the cathode reaction, the change in the molar mass of nitrogen and the water generated by the reaction, n i,cn,in and n i,cn,out represent the molar flow rates of cathode gas i (oxygen, nitrogen, water vapor) flowing in and out, respectively, is the molar mass of water produced by the reaction, is the molar mass of oxygen in the flow channel, which is equal to the consumption of hydrogen.

[0096] The PEMFC energy balance can be calculated using the enthalpy value:

[0097]

[0098] In the formula, e represents the electrode, which is the anode and cathode, i is the component, dmh e represents the enthalpy value of electrode e, n e Indicates the number of mixed gas components, dn i,e represents the molar flow rate of component i at electrode e, M i represents the molar mass of i, P e and T e denote the pressure and temperature of the mixed components at electrode e, h spec,i represents the specific enthalpy of component i, h spec,i (P e ,T e ) represents the basic thermodynamic correlation.

[0099] The diffusion rate of each component of the mixed gas can be calculated by Fick's law:

[0100]

[0101] In the formula, C and x represent the concentration and diffusion scale of the mixed gas, respectively, and D effThe effective diffusion coefficient of the reactants is expressed. The transfer of reactants on the catalyst surface of the reactor and in the porous medium of the SOFC can be described by combining Knudsen diffusion and binary diffusion. The effective diffusion coefficient can be expressed as:

[0102]

[0103] in, and are the binary diffusion coefficients of components AB and the Knudsen diffusion coefficient of component A, respectively. ε represents the porosity of the porous medium, τ represents the tortuosity, and D AB is the binary diffusion coefficient, D Ak is the Knudsen diffusion coefficient.

[0104] The binary diffusion coefficient D AB It can be expressed as:

[0105]

[0106] Among them, T cell Indicates the temperature of a single cell, v A and v B Represent the molar diffusion volume of component A and component B, M A and M B represent the molar masses of components A and B respectively, and P represents the diffusion pressure.

[0107] Knudsen diffusion coefficient D Ak It can be expressed as:

[0108]

[0109] Where r represents the pore size of the porous medium.

[0110] Porous media permeability k p It can be calculated by the Kozeny-Carman correlation:

[0111]

[0112] Where h k is the Kozeny-Carman constant, A g is the specific surface area of the porous medium particles, and ε represents the porosity of the porous medium. The diffusion mass flow rate m can be calculated by Darcy.

[0113]

[0114] Where A is the cross-sectional area, ρ is the fluid density, μ is the fluid viscosity, L is the diffusion distance, and P is the diffusion distance. up and P downRepresent the downstream and upstream pressures in the diffusion direction respectively. The heat generation and temperature balance of PEMFC can be expressed thermodynamically as:

[0115]

[0116] Where, T st Indicates the PEMFC stack temperature, m st is the mass of the battery stack; c p,st is the specific heat capacity of the stack; Q gen Indicates that when a fuel cell is working, hydrogen and oxygen react to release energy; P st Indicates the power output of the battery stack; Q water Indicates that cooling water takes away heat; Q gas Indicates that the gas flow in the cathode and anode flow fields takes away the heat.

[0117]

[0118] P st =N cell I cell V stack (twenty two)

[0119] Q gas,e =k e h conv,e A e (T e -T st ) (twenty three)

[0120]

[0121] Where, represents the lower calorific value of hydrogen, e represents the electrode; k e Indicates the gain of heat exchange; h conv,e Indicates the heat exchange coefficient; A e is the heat exchange area; T e represents the reaction gas temperature. Nu is the Nusselt number; λ is the thermal conductivity; l conv Represents the characteristic length of heat exchange.

[0122] The dynamic model of the circulating water pump can be calculated by the following formula:

[0123]

[0124] T torq =V d (p out -p in ) (26)

[0125] Where m represents mass flow rate, h in and h outare the specific enthalpies at the pump inlet and outlet, T torq Indicates torque, R s is the pump speed, V d is the pump displacement, p in and p out Indicates the inlet and outlet pressure of the pump.

[0126] The heat exchanger of the cooling system (heat pump evaporator) is simulated using the heat exchange pipes of the thermal fluid library and the two-phase flow library respectively, and the thermal port is connected through the heat capacity module to realize the coupled simulation of different fluid libraries. E It can be expressed as:

[0127] Q E =h conv A E (T fluid -T wall )k g (27)

[0128]

[0129] Where Q E is the heat transfer, h conv represents the convective heat transfer coefficient, A E Indicates the heat exchange area, T fluid represents the fluid temperature, T wall Represents the wall temperature, which can be calculated by the heat capacity model, k g represents the heat transfer gain, A cross Indicates the cross-sectional area of the heat exchange tube, L indicates the tube length, and D h Indicates the hydraulic diameter of the pipeline.

[0130] The heat capacity of a solid can be connected by multiple hot ends, and the internal temperature can be calculated using the following formula:

[0131]

[0132] Where n represents the number of heat exchange ports connected to the solid heat capacity module, dh i represents the heat flow at port i, m s represents the mass of the solid, c p,s Represents specific heat capacity.

[0133] The heat pump subsystem consists of an evaporator, a compressor, a condenser, an electronic expansion valve, a liquid storage tank and a buffer tank.

[0134] The condenser is modeled using the same approach as the cooling system heat exchanger, and the compressor mass model is as follows:

[0135]

[0136] Where m represents the compressor exhaust volume, ηv represents the compressor volumetric efficiency, ρsuc represents the suction density, and R s Indicates the speed, V d is the compressor displacement.

[0137] The energy balance can be calculated from the adiabatic efficiency:

[0138] h dis -h suc = ηis (h d -h suc ) (31)

[0139] Where h dis is the adiabatic emission specific enthalpy, h suc represents the specific enthalpy of suction, h d represents the emission specific enthalpy, η is Represents the adiabatic efficiency. The expansion valve is simulated using a throttle valve model. The controller generates a throttling area signal based on the difference between the set superheat and the actual superheat, making real-time adjustments.

[0140] The relationship between the voltage values in the electrolytic cell model can be expressed as:

[0141] V cell =V rev +V act +V ohm +V con (32)

[0142] Where: V rev Represents the equilibrium voltage of the electrolytic cell reaction; V act Represents the activation overpotential of the electrolytic cell; V ohm represents the ohmic overpotential of the electrolytic cell; V con Represents the concentration overpotential of the electrolytic cell, V cell Indicates the single battery voltage.

[0143] Theoretically, the concentration difference overpotential V con The value is often small and much smaller than the contact resistance voltage V ohm and activation overpotential V act .

[0144] Among them, V rev The equilibrium voltage can be calculated as follows:

[0145]

[0146] Where: is the standard potential; P, T, R, and F are working pressure, working temperature, universal gas constant, and Faraday constant, respectively; is the pressure of wet hydrogen and oxygen near the electrodes; is the vapor pressure of pure water. The first term is the standard potential, which is greatly affected by the operating temperature and can be determined by the following formula:

[0147]

[0148]

[0149]

[0150] Where, w 、 T represent the concentration of electrolyte potassium hydroxide and electrolysis temperature respectively.

[0151] The activation overpotential is the voltage required for an electrochemical reaction to break equilibrium and initiate forward flow. This occurs at both electrodes, with the overvoltage being greater on the anode in most cases. The Butler-Volmer equation is commonly used to calculate the activation overpotential:

[0152]

[0153] Where: j 0,a and j 0,c are the current density coefficients of the anode and cathode respectively; α a and α c are the charge transfer coefficients at the anode and cathode, respectively. In this model, it is assumed that the charge transfer coefficients for the forward and reverse reactions at the positive and negative electrodes are the same. The current density coefficients at the anode and cathode are as follows:

[0154]

[0155]

[0156] Where, P represents working pressure, P ref represents the reference pressure, R is the ideal gas constant, T is the PEMFC operating temperature, T ref Indicates the reference temperature. Charge transfer coefficient calculation:

[0157] α a =0.07835+0.001T (40)

[0158] α c =0.1175+0.00095T (41)

[0159] The transfer of ions or electrons causes an ohmic overvoltage. The main ohmic components in the electrolyzer are the electrodes, electrolyte, and membrane. The resistance of the bipolar plates is assumed to be negligible. According to Ohm's law, the overvoltage can be calculated by multiplying the total resistance by the current. This loss is described by the membrane resistance:

[0160]

[0161] Where: δ m is the film thickness; σ m is the membrane conductivity; j is the current density.

[0162] The functional relationship between membrane conductivity and water content and temperature is usually calculated using the following formula:

[0163]

[0164] The membrane water content λ is calculated as:

[0165] λ=0.08533T-6.77632 (44)

[0166] Based on the above calculations, the total input power of the alkaline stack can be expressed as:

[0167] W stack =V stack × J=(V cell ·N)×(j·A cell ) (45)

[0168] Where: W stack is the total input power of the stack; N is the number of batteries; A cell is the effective area, J is the stack output current, V stack Indicates the stack voltage, V cell represents the voltage of a single electrolytic cell, and j is the current density.

[0169] Photovoltaic power generation model, efficiency can be calculated by the following formula:

[0170] η PV / T,e =η ref [1-β ref (T PV / T -T ref )] (46)

[0171] Where η PV / T,e represents the photovoltaic thermal efficiency, η ref Indicates that the photovoltaic ref The power generation efficiency, β ref Indicates the reference temperature coefficient, T PV / T Indicates the effective temperature of the PV / T (solar photovoltaic / thermal) module, which can be obtained from the PV temperature T PV , cooling water temperature T WA and ambient temperature T a calculate:

[0172] T PV / T =T PV +(T WA-T a ) (47)

[0173] T WA =(T in -T out ) / 2 (48)

[0174] Where, T WA PV / T represents the average temperature of the cooling fluid, which can be obtained from the cooling water inlet and outlet temperatures T in and T out Calculated. PV / T thermal efficiency can be obtained by the formula:

[0175] η PV / T,t =0.7-3.4(T PV / T -T a ) / G (49)

[0176] Where G is the irradiance, PV / T is the electrical output power P el and heat load Q th They are:

[0177] P el =N PV / T η PV / T,e τGA PV / T (50)

[0178] Q th =N PV / T GA PV / T τη PV / T,t (1-η PV / T,e )=c p m P (T in -T out ) (51)

[0179] Where τ represents the optical efficiency, N PV / T Indicates the number of photovoltaic panels, A PV / T represents the photovoltaic effective area, c p Indicates the specific heat capacity of cooling water, m P Expressing the mass flow rate of cooling water by PV / T, the PV / T efficiency is:

[0180] η PV / T =(P el +Q th ) / GA PV / T (52)

[0181] Lithium battery model: open circuit voltage V bat and internal resistance R bat are all functions of the state of charge (SOC). According to the lithium battery equivalent circuit model, the current I bat Calculate according to the following formula.

[0182]

[0183] P bat Indicates the output power of the lithium battery pack. According to the ampere-hour integration method, the relationship between current and SOC is as follows:

[0184] SOC=SOC0-∫I bat η colm / Q bat (54)

[0185] Where SOC0 is the initial state of charge, η colm is the Coulomb efficiency, Q bat is the capacity of lithium battery.

[0186] According to formula (53) and formula (54), the power of the lithium battery in both charging and discharging states is as follows.

[0187]

[0188] Lithium battery pack output power P bat The calculation formula is as follows.

[0189] P bat =n bat n pack P sig (56)

[0190] Where n bat is the number of battery packs, n pack is the number of lithium battery cells in the battery pack, P sig The power of a single battery.

[0191] according to Figure 3 The above models are integrated into a modular system structure to create subsystem models. These subsystem models are then integrated into an overall model of a low-carbon building-focused electric, hydrogen, and heat energy system using model interfaces. Simulation software is used to perform system-level simulations, analyzing the system's performance under different operating strategies and providing data support for optimal decision-making.

[0192] Figure 4 Schematic diagram for modeling the fuel cell cogeneration subsystem. Figure 4 The system pump, compressor, fuel cell, heat exchanger and related basic models are all dynamic models integrated into the AMESim software. Based on the subsystem structure, the equipment models of each component are connected according to the model interface. The subsystem simulation model is established by setting the model parameters (referring to the system component parameters, such as compressor displacement, fuel cell capacity, etc., which are determined based on the system load).

[0193] Figure 5 Modeling diagram for the heat pump air conditioning subsystem. Figure 5 The compressor, throttle valve, heat exchanger and related basic models are all dynamic models integrated into the AMESim software. Based on the subsystem structure, the equipment models of each component are connected according to the model interface, and the subsystem simulation model is established by setting the model parameters.

[0194] Figure 6A 、 6B This is the dynamic response of the key system parameters of the fuel cell cogeneration subsystem under the condition of dynamic current step. The voltage overshoots during the current step, which is mainly caused by the fuel depletion caused by the current step and the lack of gas in the fuel cell. Due to the voltage overshoot, the output power and heat generation of the stack show overshoot and reverse spikes.

[0195] Figure 7A 、 7B This figure shows the dynamic response of key system parameters to a step-change in the compressor speed of the heat pump air conditioning subsystem. The dynamic response time for the compressor outlet pressure is 10 seconds. Heat changes during the condensation and evaporation processes are affected by pressure fluctuations, and the response also has a lag.

[0196] In summary, the present invention establishes a dynamic mechanism model of the electric, hydrogen and heat integrated energy system for low-carbon buildings based on the AMESim software platform, adopts a modular modeling method to reduce modeling time, and can accurately reflect the coupling relationship and dynamic characteristics within the electric, hydrogen and heat integrated energy system, help predict the dynamic changes of the system under different load conditions, and promote the progress of engineering design and optimization process.

[0197] Corresponding to the above-mentioned embodiment of the electric, hydrogen and heat integrated energy system modeling method for low-carbon buildings, the present invention also proposes a electric, hydrogen and heat integrated energy system modeling system for low-carbon buildings.

[0198] Figure 8 This is a structural block diagram of a low-carbon building electric-hydrogen-heat integrated energy system modeling system according to an embodiment of the present invention.

[0199] like Figure 8 As shown, the electric, hydrogen and heat integrated energy system modeling system for low-carbon buildings includes: a determination module 10 for determining the different physical fields involved in the electric, hydrogen and heat integrated energy system for low-carbon buildings and the mechanism models under each physical field, and determining the model interface of each mechanism model; a first establishment module 20 for establishing the dynamic model of each component equipment of the electric, hydrogen and heat integrated energy system according to the mechanism models under the physical fields; a second establishment module 30 for establishing each subsystem model of the electric, hydrogen and heat integrated energy system based on the dynamic model of each component equipment; a combination module 40 for combining the subsystem models according to the model interface to obtain the electric, hydrogen and heat integrated energy system model for low-carbon buildings.

[0200] It should be noted that the specific implementation of the electric, hydrogen and heat integrated energy system modeling system for low-carbon buildings can be found in the specific implementation of the electric, hydrogen and heat integrated energy system modeling method for low-carbon buildings mentioned above. To avoid redundancy, it will not be described in detail here.

[0201] The electric, hydrogen and heat integrated energy system modeling system for low-carbon buildings in the embodiment of the present invention is based on a modular modeling approach and divides modeling models according to different fields. It can accurately reflect the coupling relationship and dynamic characteristics within the electric, hydrogen and heat integrated energy system, and help predict the dynamic changes of the system under different load conditions.

[0202] In the description of this specification, the reference terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" and the like are intended to mean that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are exemplary and are not to be construed as limiting the present invention. Those skilled in the art may make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A modeling method for an electric, hydrogen and thermal integrated energy system for low-carbon buildings, characterized by: The following steps are involved: Identify the different physical fields involved in the electric, hydrogen and heat integrated energy system for low-carbon buildings, the mechanism models under each physical field, and determine the model interface of each mechanism model; Establish dynamic models of various components and equipment of the electric, hydrogen and thermal integrated energy system based on the mechanism models under the various physical fields; Based on the dynamic models of the various components and equipment, establish the subsystem models of the electric, hydrogen and heat integrated energy system; The subsystem models are combined according to the model interface to obtain an electric, hydrogen and thermal integrated energy system model for low-carbon buildings.

2. The electric, hydrogen and heat integrated energy system modeling method for low-carbon buildings according to claim 1 is characterized in that: The physical domain includes at least one of a fluid domain, an electrical domain, a thermal domain, and a gas domain.

3. The electric, hydrogen and heat integrated energy system modeling method for low-carbon buildings according to claim 1 is characterized in that: The mechanism model includes multiple types of physical process mechanism models, chemical process mechanism models and power process mechanism models.

4. The electric, hydrogen and heat integrated energy system modeling method for low-carbon buildings according to claim 1 is characterized in that: The model interface is a model interface based on the AMESim software platform.

5. The electric, hydrogen and heat integrated energy system modeling method for low-carbon buildings according to claim 1 is characterized in that: The various components and equipment include various types of pumps, compressors, heat exchangers, valves, pipelines, fuel cells, electrolytic cells, lithium batteries, photovoltaics, storage tanks and separation tanks.

6. The electric, hydrogen and heat integrated energy system modeling method for low-carbon buildings according to claim 5 is characterized in that: The subsystems include multiple types of power subsystem, thermal energy subsystem, hydrogen subsystem, photovoltaic subsystem, water electrolysis hydrogen production subsystem, hydrogen storage subsystem, fuel cell cogeneration subsystem and heat pump air conditioning subsystem. The power subsystem is used for power transmission; The thermal energy subsystem is used for thermal energy transmission; The hydrogen subsystem is used for hydrogen transmission; The photovoltaic subsystem is used for photovoltaic power generation; The water electrolysis hydrogen production subsystem is used to perform water electrolysis based on the electrical energy provided by the photovoltaic subsystem to produce hydrogen and oxygen; The hydrogen storage subsystem is used to store the hydrogen produced by the water electrolysis hydrogen production subsystem; The fuel cell cogeneration subsystem is used to generate electricity and heat based on the hydrogen produced by the water electrolysis hydrogen production subsystem; The heat pump air conditioning subsystem is used to generate heat based on the electric energy provided by the photovoltaic subsystem and the fuel cell cogeneration subsystem; The lithium battery is used to store the electrical energy provided by the photovoltaic subsystem and the fuel cell cogeneration subsystem.

7. The electric, hydrogen and heat integrated energy system modeling method for low-carbon buildings according to claim 6 is characterized in that: The photovoltaic subsystem, water electrolysis hydrogen production subsystem, fuel cell cogeneration subsystem, heat pump air conditioning subsystem, and lithium battery are respectively connected to the power subsystem; the fuel cell cogeneration subsystem and heat pump air conditioning subsystem are respectively connected to the thermal energy subsystem; the water electrolysis hydrogen production subsystem, hydrogen storage subsystem, and fuel cell cogeneration subsystem are respectively connected to the hydrogen subsystem.

8. A modeling system for an electric, hydrogen and thermal integrated energy system for low-carbon buildings, characterized by: include: A determination module is used to determine the different physical fields involved in the electric, hydrogen and heat integrated energy system for low-carbon buildings, the mechanism models under each physical field, and the model interface of each mechanism model; The first establishment module is used to establish a dynamic model of each component of the electric, hydrogen and heat integrated energy system according to the mechanism model under each physical field; The second establishment module is used to establish the subsystem models of the electric, hydrogen and heat integrated energy system based on the dynamic models of the components and equipment; A combination module is used to combine the subsystem models according to the model interface to obtain an electric, hydrogen and thermal integrated energy system model for low-carbon buildings.

Images