Multi-energy-quality-flow integrated precise modeling method for green hydrogen metallurgy integrated energy system

Abstract

The present invention discloses a method for precise modeling of multi-energy and mass flow integration of green hydrogen metallurgical integrated energy system. First, by focusing on the green hydrogen metallurgical integrated energy system, and aiming at the problem that the transmission characteristics of heterogeneous energy flows and material flows are greatly different and difficult to describe in a unified manner, a unified mathematical equation for multi-energy and mass flow transmission based on differential dynamics is proposed. Secondly, in order to simplify complex dynamic problems, the time domain dynamics is converted into a static algebraic problem, and a generalized transmission model based on distributed parameters is constructed. In response to the challenge of heterogeneous distribution parameters of multi-energy and mass flow branches and nodes, an equivalent modeling method for branches and node external ports is further proposed, and the description system of multi-energy and mass flow integrated modeling is improved. Finally, based on the above-mentioned algebraic model, the matrix modeling of the multi-energy and mass flow network is studied, a standardized matrix analysis paradigm is proposed, and by constructing a unified Jacobian matrix, the rapid calculation of the multi-energy and mass flow distribution is realized, providing precise support for the coordinated regulation of multiple links in the system.

Description

Technical Field

[0001] The present invention belongs to the technical field of building integrated energy system flow models, and specifically relates to a method for integrating multi-energy and mass flow precise modeling of a green hydrogen metallurgical integrated energy system. Background Art

[0002] Green hydrogen metallurgy, a technology that replaces carbon-based reducing agents with hydrogen, is emerging as a key path forward for clean metallurgy. This technology produces hydrogen through water electrolysis, utilizing green hydrogen as a reducing agent to reduce carbon emissions during the smelting process and achieve a deep integration of clean energy and steel production. To ensure the efficient operation of green hydrogen metallurgy integrated energy systems, accurate modeling and system optimization are crucial. However, given the complex energy and mass flows and multi-energy flow coupling inherent in metallurgical processes, achieving unified system modeling remains a significant challenge.

[0003] Currently, existing research has made some progress in modeling the coupling relationship between material flow and energy flow, especially in the study of traditional steelmaking processes. Existing models mainly focus on the interaction between material flow properties and energy flow, and construct analytical methods for energy and mass flow distribution under steady-state conditions. Most of these models are oriented towards specific links such as reduction and combustion, and the energy flows involved are mostly steady-state processes. For example, the coupling of gas flow and thermal energy flow in the reduction process is usually described by a fixed energy conservation equation. In addition, some models have also begun to consider the electric hydrogen production and electric heating links in the metallurgical process, but overall there is still a lack of in-depth analysis of the complex dynamic coupling within the system.

[0004] Although existing models have made progress in some aspects, there are still obvious deficiencies in the integrated modeling of green hydrogen metallurgical integrated energy systems. First, current models are mostly based on steady-state analysis and cannot fully consider the dynamic changing characteristics of multiple energy flows in time and space. In particular, existing models have great limitations in dealing with the unification of transient characteristics of electricity and steady-state characteristics of material flows. Secondly, existing models mainly focus on the conversion of single energy and mass flows in the reduction process, ignoring the complex interactions between multiple links, such as the coupling characteristics between electric hydrogen production, electric heating and reduction reactions. In addition, differences in time granularity and spatial distribution will cause ill-posed problems of the Jacobian matrix during the calculation process, further reducing the accuracy and efficiency of the calculation. Therefore, how to achieve accurate analysis of energy and mass flows at different time scales and spatial distributions remains a key issue that needs to be solved urgently. Summary of the Invention

[0005] In response to the above-mentioned deficiencies in the prior art, the multi-energy-mass flow integrated precise modeling method of the green hydrogen metallurgical integrated energy system provided by the present invention solves the problems in the above-mentioned background technology and effectively realizes the multi-energy-mass flow integrated analysis of the green hydrogen metallurgical integrated energy system.

[0006] In order to achieve the above-mentioned purpose of the invention, the technical solution adopted by the present invention is: a multi-energy and mass flow integrated precise modeling method for the green hydrogen metallurgical integrated energy system, comprising the following steps:

[0007] S1. Analyze the transmission dynamic characteristics and coupled transformation dynamic characteristics of multiple energy and mass flows in the green hydrogen metallurgical integrated energy system, and construct a transmission characteristic model and coupled transformation process model of multiple energy and mass flows;

[0008] S2. Using the unified mathematical equation of multi-energy-mass flow based on differential dynamics equation, the transmission characteristic model and coupled transformation process model of multi-energy-mass flow are expressed as the unified dynamic equation of multi-energy-mass flow transmission and the unified dynamic equation of multi-energy-mass flow coupled transformation, respectively;

[0009] S3. Perform transmission static algebraic analysis based on Laplace transform and branch external port equivalence based on distributed parameter approximation on the unified dynamic equations of multi-energy and mass flow transmission, and construct a unified model of multi-energy and mass flow;

[0010] The unified dynamic equations of multi-energy-mass-flow coupled transformation are subjected to the static algebraic analysis of energy-mass conversion based on Laplace transform and the external port equivalence of coupling nodes based on distributed parameter approximation, thus constructing a unified model of multi-energy-mass-flow coupled transformation.

[0011] S4. Based on the unified model of multiple energy and mass flows and the unified model of multiple energy and mass flow coupling transformation, a universal matrix dynamic characteristic equation of the multi-energy and mass flow network is constructed;

[0012] S5. Calculate the heterogeneous network boundary values in the multi-energy mass flow network based on the dynamic characteristic equation of the entire network;

[0013] S6. Based on the boundary values of the heterogeneous network, a unified Jacobian matrix of the green hydrogen metallurgical integrated energy system is constructed, and the distribution calculation and analysis of multiple energy and mass flows are performed.

[0014] Furthermore, in step S1, the multi-energy and mass flow transmission characteristic model includes an electric current (carbon) flow equation, a thermodynamic (carbon) flow equation, a hydrogen (carbon) flow equation, and a material flow equation;

[0015] The coupled conversion process model of multiple energy and mass flows includes an electric-thermal conversion process model, an electric-hydrogen conversion process model, and a material conversion process model.

[0016] Furthermore, the step S2 is specifically as follows:

[0017] The physical quantities in the transmission characteristic model and the transformation process model are classified into intensity quantities and extensive quantities. In the unified dynamic equation of multi-energy and mass flow transmission and the unified dynamic equation of multi-energy and mass flow coupling transformation, the spatial differentials of the intensity quantities and the extensive quantities are used to represent the left side of the equal sign, and the time differentials of the intensity quantities and the extensive quantities and related terms are used to represent the right side of the equal sign.

[0018] Furthermore, the unified dynamic equation of multi-energy-mass flow transmission corresponding to the transmission characteristic model and the unified dynamic equation of multi-energy-mass flow coupling transformation corresponding to the coupled transformation process model are identical in form and are both expressed as:

[0019]

[0020] Where ψ represents the generalized intensity quantity, ζ represents the extension quantity, and α1, α2, β1, and β2 represent branch parameters.

[0021] Furthermore, in step S3, when performing a Laplace transform-based transmission static algebraic analysis on the unified dynamic equation of multi-energy-mass flow transmission, and performing a Laplace transform-based energy-mass conversion static algebraic analysis on the unified dynamic equation of multi-energy-mass flow coupling conversion, they are both expressed in the Laplace domain as:

[0022]

[0023] Where ψ(x,s)=L(ψ(x,t)), ζ(x,s)=L(ζ(x,t)), L(·) represents the Laplace transform operator, and the complex number s represents the Laplace transform parameter;

[0024] The unified dynamic equation of multi-energy-mass flow transmission after Laplace transformation is equivalent to the branch external port based on the distributed parameter approximation, and the unified dynamic equation of multi-energy-mass flow coupling transformation after Laplace transformation is equivalent to the coupling node external port based on the distributed parameter approximation. The obtained unified model of multi-energy-mass flow and the unified model of multi-energy-mass flow coupling transformation are the same in form and are expressed as:

[0025]

[0026] Where, and ε denote the approximation operator, a and b are integration constants determined by the boundary conditions.

[0027] Furthermore, in step S4, the constructed universal matrix multi-energy mass flow network full network dynamic characteristic equation is expressed as:

[0028] ζ out (s)=Yζ(s)

[0029] Y=(Z -1 -D(A + ) T A - ) -1 D(A + ) T

[0030] Where Z represents the branch characteristic matrix in the multi-energy mass flow network, D represents the matrix of extensive quantity distribution coefficients, Y represents the energy node admittance matrix, ζ out (s) represents the end extension of the branch characteristic matrix, ζ(s) represents the beginning extension of the branch characteristic matrix, and z e The constant d represents the Laplace operator s of each branch loss and delay. e It represents the ratio of the starting extension of branch e to the total extension of the outflow from the same node, e represents the branch index, and E represents the branch set.

[0031] Furthermore, in step S5, the heterogeneous networks in the multi-energy and mass flow network include an electric power flow network, a thermal flow network, a material flow network, and a hydrogen flow network;

[0032] Calculating heterogeneous network boundary values in a multi-energy flow network includes the following steps:

[0033] S51, dividing the network nodes in the multi-energy mass flow network into key boundary nodes and non-key nodes according to the importance and physical properties of the network nodes;

[0034] S52, performing matrix operations on the node strength and extension injection values according to the divided node types to construct a block matrix;

[0035] S53. Perform Gaussian elimination on the constructed block matrix to obtain the boundary equivalent equation of the multi-energy flow network that only contains key boundary nodes, and then calculate the boundary equivalent of the heterogeneous network.

[0036] Furthermore, in step S52, the constructed block matrix is expressed as:

[0037]

[0038] Where Y BB , Y BI , Y IB , Y II represents the block matrix of Y, Y represents the energy node admittance matrix, ψ B (s) and ψ I (s) represents two sets of node strength divided by node type, ζ B (s) and ζ I (s) represents two sets of values injected into the extensive quantity divided by node type;

[0039] In step S53, the boundary equivalence equation is expressed as:

[0040]

[0041] Furthermore, in step S6, the unified Jacobian matrix of the constructed green hydrogen metallurgical integrated energy system is expressed as:

[0042]

[0043] Where, It represents the extensive quantity and intensive quantity characterization of process J in the green hydrogen metallurgical integrated energy system. The subscripts m and n represent the parameter indexes in the green hydrogen metallurgical integrated energy system.

[0044] The beneficial effects of the present invention are:

[0045] (1) The present invention discloses a method for precise modeling of multi-energy and mass flow integration in a green hydrogen metallurgical integrated energy system. First, by focusing on the green hydrogen metallurgical integrated energy system, and addressing the problem that the transmission characteristics of heterogeneous energy flows and material flows are greatly different and difficult to describe in a unified manner, a unified mathematical equation for multi-energy and mass flow transmission based on differential dynamics is proposed. Secondly, in order to simplify complex dynamic problems, the time domain dynamics is converted into a static algebraic problem, and a generalized transmission model based on distributed parameters is constructed. In response to the challenge of heterogeneous distribution parameters of multi-energy and mass flow branches and nodes, an equivalent modeling method for branches and node external ports is further proposed, and the description system of multi-energy and mass flow integrated modeling is improved. Finally, based on the above-mentioned algebraic model, the matrix modeling of the multi-energy and mass flow network is studied, a standardized matrix analysis paradigm is proposed, and by constructing a unified Jacobian matrix, the rapid calculation of the multi-energy and mass flow distribution is realized, providing precise support for the coordinated regulation of multiple links in the system.

[0046] (2) The present invention aims to uniformly describe the transmission characteristics of heterogeneous energy and material flows, simplify their dynamic analysis process, solve the complex description problem of multiple energy and material flows through algebraic modeling and equivalent modeling methods, and ultimately provide accurate matrix modeling and fast computing support to optimize the coordinated regulation of integrated energy systems.

[0047] (3) The present invention proposes an innovative modeling method that uniformly describes the transmission characteristics of heterogeneous energy flows and material flows through differential dynamics, solving the problem that traditional modeling methods cannot simultaneously handle the differences in the transient characteristics of power and the steady-state characteristics of material flows, thereby realizing the precise modeling of the integration of multiple energy and material flows in the green hydrogen metallurgical integrated energy system.

[0048] (4) The present invention innovatively transforms the complex dynamic coupling of multiple energy and mass flows into a static algebraic problem through algebraic means, and realizes the rapid distributed calculation and analysis of the multiple energy and mass flow network by constructing a unified Jacobian matrix, which simplifies the regulation and optimization process of the multiple energy and mass flow system and improves the computational efficiency and accuracy of the integrated energy system. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1Flowchart of the multi-energy and mass flow integrated precise modeling method for the green hydrogen metallurgical integrated energy system provided by the present invention.

[0050] Figure 2 Schematic diagram of the framework for constructing the unified multi-energy and mass flow model provided by the present invention.

[0051] Figure 3 Schematic diagram of the framework for constructing a unified model of multi-energy-mass-flow coupling conversion provided by the present invention.

[0052] Figure 4 Schematic diagram of the integrated distribution and calculation framework of energy and mass flow achieved by the multi-energy and mass flow network provided by the present invention. DETAILED DESCRIPTION

[0053] The specific embodiments of the present invention are described below to facilitate understanding of the present invention by those skilled in the art. However, it should be clear that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the appended claims, these changes are obvious, and all inventions and creations utilizing the concepts of the present invention are protected.

[0054] The embodiment of the present invention provides a multi-energy and mass flow integrated accurate modeling method for a green hydrogen metallurgical integrated energy system. Figure 1 As shown, the following steps are included:

[0055] S1. Analyze the transmission dynamic characteristics and coupled transformation dynamic characteristics of multiple energy and mass flows in the green hydrogen metallurgical integrated energy system, and construct a transmission characteristic model and coupled transformation process model of multiple energy and mass flows;

[0056] S2. Using the unified mathematical equation of multi-energy-mass flow based on differential dynamics equation, the transmission characteristic model and coupled transformation process model of multi-energy-mass flow are expressed as the unified dynamic equation of multi-energy-mass flow transmission and the unified dynamic equation of multi-energy-mass flow coupled transformation, respectively;

[0057] S3. Perform transmission static algebraic analysis based on Laplace transform and branch external port equivalence based on distributed parameter approximation on the unified dynamic equations of multi-energy and mass flow transmission, and construct a unified model of multi-energy and mass flow;

[0058] The unified dynamic equations of multi-energy-mass-flow coupled transformation are subjected to the static algebraic analysis of energy-mass conversion based on Laplace transform and the external port equivalence of coupling nodes based on distributed parameter approximation, thus constructing a unified model of multi-energy-mass-flow coupled transformation.

[0059] S4. Based on the unified model of multiple energy and mass flows and the unified model of multiple energy and mass flow coupling transformation, a universal matrix dynamic characteristic equation of the multi-energy and mass flow network is constructed;

[0060] S5. Calculate the heterogeneous network boundary values in the multi-energy mass flow network based on the dynamic characteristic equation of the entire network;

[0061] S6. Based on the boundary values of the heterogeneous network, a unified Jacobian matrix of the green hydrogen metallurgical integrated energy system is constructed, and the distribution calculation and analysis of multiple energy and mass flows are performed.

[0062] In step S1 of the embodiment of the present invention, the multi-energy and mass flow transmission characteristic model includes the current (carbon) flow equation, the thermodynamic (carbon) flow equation, the hydrogen (carbon) flow equation and the material flow equation, specifically;

[0063] Current (carbon) flow equation:

[0064] Power flow refers to the electrical power transmitted along power lines, also known as current flow, and is a fundamental subject of power system research. The transmission of AC power flow satisfies Maxwell's equations, and it can generally be assumed that the transmission line medium is uniform. The classic mathematical equation is:

[0065]

[0066] Where U and I are the voltage and current of the power flow at position x of the transmission line at time t, respectively; R and L are the branch resistance and reactance per unit length, respectively; G and C are the admittance and capacitance per unit length, respectively.

[0067] The essence of the carbon emission flow of the power system lies in quantitatively determining the flow state of carbon emissions through the distribution of power flow, thereby tracing the source and destination of carbon emissions. The carbon emission flow depends on the existence of power flow, and any factor that affects the power flow distribution will affect the carbon emission flow. Since the energy consumption and carbon emissions in the system are mainly related to the active power output of the power source and are less affected by the reactive power output, the carbon emission flow is mainly determined by the active power flow. Therefore, in the green hydrogen integrated energy system, the power and carbon flow equations are both established through Equation (1).

[0068] Thermodynamic (carbon) flow equation:

[0069] Thermal flow refers to the heat power transferred along a heating network. Heat transfer within a heating network is a composite process of heat transfer caused by the movement of the working medium and heat exchange between the network and the surrounding environment. Heat transfer in a one-dimensional pipeline is represented by the variation of water temperature at different locations x with t, as expressed by the mathematical equation:

[0070]

[0071] Where: T is the temperature difference between the heat flux in the pipeline at position x at time t and the environment outside the pipeline (usually soil), which is a function of x and t; m is the mass flow rate of the heat flux carrier; c is the specific heat capacity of the heat flux carrier; ρ is the density of the heat flux carrier; λ is the thermal conductivity of the pipeline; γ0 is the radial thermal diffusivity of the heat flux; and A is the cross-sectional area of the pipeline in the thermal branch.

[0072] The first and second terms on the left side of the equation represent heat conduction by forced convection, the third term on the left side of the equation represents static heat conduction within the heat flux carrier, and the fourth term on the left side of the equation represents heat loss during transmission. Since the thermal conductivity of heat flux carriers is typically very low, approximately 0.59 W / mK, much lower than the thermal conductivity of common metals (copper has a thermal conductivity of 403 W / mK and iron has a thermal conductivity of 86.5 W / mK), static heat conduction within the heat flux carrier can usually be ignored, simplifying equation (2) to:

[0073]

[0074] Let heat flow power φ represent the amount of heat that can be released through the cross section of the pipe per unit time, that is, the heat of the part of the heat flow that is higher than the ambient temperature (the temperature of the high-temperature heat source cannot be lower than that of the low-temperature heat source after releasing heat). According to the definition of specific heat capacity, we know that:

[0075] φ=cmT(4)

[0076] In addition, the primary heat network in the thermal system generally adopts a mass regulation operation mode. This method does not change the thermal distribution of the pipe network, but only adjusts the heating temperature at the heat source to meet the heat load. It has the advantages of simple operation and management and stable system hydraulic conditions. Therefore, the mass flow rate m of the heat flow can be regarded as a constant. Combining equations (3) and (4), the one-dimensional thermal flow equation with φ and T as dual variables can be obtained as:

[0077]

[0078] Similar to electricity (carbon) flow, in a heat transmission network, carbon emission flows are dependent on the heat flow transmission path, so the distribution of heat flow directly affects the flow of carbon emissions. In the green hydrogen integrated energy system, the carbon emission flows of both heat and electricity transmission networks are analyzed using similar mechanisms. Therefore, the interdependence of carbon flow and heat flow leads to the unified modeling of the thermal (carbon) flow equations in the system using Equation (5) to ensure accurate calculation of carbon emission flows in the heat network.

[0079] Hydrogen (carbon) flow equation:

[0080] Since hydrogen in green hydrogen metallurgical systems is primarily obtained through water electrolysis, and hydrogen serves as a reducing agent for iron oxide to achieve metal smelting, the hydrogen transmission process in the gas network can be equivalent to energy flow. Ignoring temperature and height changes in the hydrogen pipeline, the hydrogen flow obeys the law of conservation of mass and Bernoulli's law for non-ideal gases, with pressure and flow changing along the way. The mathematical equation is:

[0081]

[0082] Where: π is the pressure of the hydrogen flow at the pipeline position x at time t; f is the flow rate of the hydrogen flow at the pipeline position x at time t (all measured under standard conditions, i.e., 1 atmosphere and temperature of 25°C); ρ h is the density of hydrogen under standard conditions, ρ h f is the mass flow rate; R h is the specific gas constant of hydrogen (the gas constant divided by the molar mass of natural gas); z is the friction factor of the pipeline, which is the main factor causing the pressure loss of hydrogen transmission; D is the diameter of the pipeline.

[0083] The partial derivative of the flow rate with respect to time in Equation (6) has little effect on the accuracy of the equation, especially when the pipeline flow rate does not change dramatically and the pipeline capacity is large, the impact on the accuracy is less than 1%. Since in the green hydrogen metallurgical integrated energy system, the power and hydrogen systems are mainly coupled through the vertical furnace green hydrogen metallurgy and electrolytic water equipment, the partial derivative of the flow rate with respect to time is ignored, and Equations (6) and (7) are approximated as:

[0084]

[0085] Consistent with previous modeling ideas, in the hydrogen transmission network, the carbon emission flow is also dependent on the flow of hydrogen. In the green hydrogen metallurgical system, hydrogen is mainly produced by electrolysis of water and used as a reducing agent in the smelting process of iron oxide, thereby realizing the refining of metals. Since the transmission process of hydrogen can essentially be regarded as a kind of energy flow, the carbon flow in the gas network not only represents the flow of matter, but also reflects the transfer of energy. Therefore, when constructing the hydrogen (carbon) flow equation of the green hydrogen integrated energy system, a modeling method similar to that of electricity and heat flow is adopted.

[0086] Material flow equation:

[0087] Since the green hydrogen metallurgical system's electromagnetic furnace heating process primarily heats iron ore through electromagnetic induction, changes in the magnetic field generate eddy currents within the iron ore, leading to material flow. This material flow change can be equated to the flow of magnetic flux and frequency. Ignoring the temperature gradient and height differences of the iron ore, material flow obeys the law of conservation of energy and Faraday's law of electromagnetic induction. The magnetic flux and frequency vary with time and space, and the equation is:

[0088]

[0089] Where: is the magnetic flux difference at position x at time t; f h and f m They represent the changes in high-frequency and low-frequency electromagnetic fields at position x at time t, respectively; M is the magnetic permeability of the system, which represents the response of the material to the change in the magnetic field; S is the cross-sectional area of the material; The initial magnetic flux represents the initial state of the magnetic field of the system.

[0090] In step S1 of the embodiment of the present invention, the above-mentioned coupled conversion process model of multiple energy and mass flows includes an electric-thermal conversion process model, an electric-hydrogen conversion process model and a material conversion process model, specifically;

[0091] Electric-thermal conversion process model:

[0092] During the electromagnetic furnace heating process of the green hydrogen metallurgical system, the material flow in the electromagnetic induction heating iron ore pellets can be regarded as energy flow. First, the interaction between the temperature change of the pellet material and the electromagnetic effect is described by the electrothermal conversion equation:

[0093]

[0094] Where: ρ 球团 is the density of the pellet; c 球团 is the specific heat capacity of the pellet; represents the change of temperature over time; k is thermal conductivity, which describes heat diffusion; is the spatial Laplace operator of the temperature field, reflecting the change of temperature in space; J is the current density; r 球团 is the resistivity of the pellet, reflecting the generation of Joule heat.

[0095] Second, the coupling of the electromagnetic field to the material flow is described by the following equation:

[0096]

[0097] Where: B is the magnetic induction intensity; μ is the magnetic permeability; J is the current density; E is the electric field intensity; υ is the electromagnetic characteristic parameter of the material, which represents the dynamic effect of electromagnetic induction changes.

[0098] Electricity-hydrogen conversion process model:

[0099] In green hydrogen metallurgical systems, the generation and transport of hydrogen involves the dynamic processes of water electrolysis and hydrogen diffusion. Ignoring temperature and pressure changes in the system, the variation of hydrogen concentration over time and space can be described by the following time-space differential equation:

[0100]

[0101] Where: C H is the hydrogen concentration at time t and position x; D H is the diffusion coefficient of hydrogen in the metallurgical system, reflecting the diffusion rate of hydrogen in space; is the Laplace operator of hydrogen concentration, which describes the change of hydrogen concentration in space; z is the charge number of hydrogen ion; F is the Faraday constant; J is the current density.

[0102] In addition, the relationship between current density J and electric field strength E can be expressed by the conductivity equation:

[0103] J=σE (13)

[0104] Where: σ is the conductivity, which describes the ability of current to be conducted in the system; E is the electric field strength in the system.

[0105] This equation describes the generation and diffusion of hydrogen in a green hydrogen metallurgical system under the influence of an electric field. Hydrogen generated by water electrolysis is transported through the system by diffusion, while the electric field drives the current, affecting the hydrogen's transport rate and spatial distribution. This process is closely related to the coupling between the electric field and material flow.

[0106] Material transformation process models;

[0107] In a green hydrogen metallurgical system, hydrogen acts as a reducing agent to react with iron oxide in iron ore, thereby achieving iron smelting. Ignoring temperature and pressure changes in the system, the changes in hydrogen and iron concentrations over time and space can be described by the following time-space differential equations:

[0108]

[0109] Where: C H is the hydrogen concentration at time t and position x; D H is the diffusion coefficient of hydrogen in the metallurgical system, which describes the diffusion rate of hydrogen in space; is the concentration of iron oxide; k1 is the rate constant of the reaction between hydrogen and iron oxide; C Fe is the concentration of generated iron; D Fe is the diffusion coefficient of iron in the system; k2 is the rate constant of the secondary reaction between iron and hydrogen.

[0110] In this embodiment, equation (14) represents the hydrogen transport and reaction process. Hydrogen not only diffuses in space but also reacts with iron oxide, resulting in a decrease in hydrogen concentration. Equation (15) describes the iron formation process. Iron concentration is affected not only by iron diffusion but also by hydrogen reducing iron oxide to form iron, which may then undergo a secondary reaction with hydrogen.

[0111] Equations (14) and (15) together describe the reaction mechanism of hydrogen and iron oxide, taking into account both the transport of substances and the effects of chemical reactions on the concentrations of hydrogen and iron, thereby constructing a detailed model of substance flow and transformation in green hydrogen metallurgical systems.

[0112] In the embodiment of the present invention, step S2 is specifically as follows:

[0113] The physical quantities in the above-mentioned transmission characteristic model and transformation process model are classified into intensity quantities and extensive quantities. In the unified dynamic equation of multi-energy and mass flow transmission and the unified dynamic equation of multi-energy and mass flow coupling transformation, the spatial differentials of intensity quantities and extensive quantities are used to represent the left side of the equal sign, and the time differentials of intensity quantities and extensive quantities and related terms are used to represent the right side of the equal sign.

[0114] Specifically, in this embodiment, in the above-mentioned transmission characteristic model, the power (carbon) flow equation, the heat (carbon) flow equation, the hydrogen (carbon) flow equation, and the material flow equation share many commonalities. On the one hand, these equations are all described by intensive quantities and extensive quantities. Intensive quantities refer to physical quantities that do not change with the scale of the system or the amount of material, such as the voltage U in the power grid, the temperature difference T in the heat grid, and the pressure change Δπ in the gas grid; extensive quantities vary proportionally with the scale of the system or the amount of material, including the current I in the power grid, the heat flow power φ in the heat grid, and the flow change Δf in the gas grid. On the other hand, the partial differential equations of the three are similar in form. The left side of the equation contains the spatial differentials of the intensive and extensive quantities, while the right side consists of the time differentials of the intensive and extensive quantities and related terms.

[0115] Based on this, in an example of this embodiment, the unified dynamic equation of multi-energy-mass flow transmission corresponding to the transmission characteristic model and the unified dynamic equation of multi-energy-mass flow coupling transformation corresponding to the coupled transformation process model are identical in form and are both expressed as:

[0116]

[0117] Where ψ represents the generalized intensity quantity, ζ represents the extension quantity, and α1, α2, β1 and β2 represent the branch parameters;

[0118] In step S3 of the embodiment of the present invention, as Figure 2 As shown, based on the unified dynamic equation of multi-energy and mass flow constructed in step S2 above, the transmission static algebraic analysis and branch external port equivalence are performed in sequence; Figure 3 As shown, based on the unified dynamic equation of multi-energy-mass-flow coupling transformation constructed in the above step S2, transmission static algebraic analysis and branch external port equivalence are performed in sequence.

[0119] Specifically, in this embodiment, the research on the green hydrogen metallurgical multi-energy system focuses on the mutual influence caused by "changes" between systems, and therefore focuses on the zero-state response of the system. Since the generalized energy flow equation is a linear equation, the initial state influence of the system in this embodiment can be handled by the "superposition theorem". When performing a Laplace transform-based transmission static algebraic analysis on the unified dynamic equation of multi-energy flow transmission, and when performing a Laplace transform-based energy-mass conversion static algebraic analysis on the unified dynamic equation of multi-energy flow coupling conversion, they are expressed in the Laplace domain as:

[0120]

[0121] Where ψ(x,s)=L(ψ(x,t)), ζ(x,s)=L(ζ(x,t)), L(·) represents the Laplace transform operator, and the complex number s represents the Laplace transform parameter.

[0122] In this embodiment, through the above-mentioned Laplace transform, the distributed parameter circuit in the time domain can be simplified into a Laplace domain distributed parameter circuit containing only spatial differentials, which uniformly represents resistance, inductance and capacitance. However, the distributed parameter circuit is still difficult to analyze directly, so it is necessary to further simplify or approximate it into a concentrated parameter circuit, so as to analyze the pipeline branch in the multi-energy network as a whole. This is similar to the approximate equivalence method of using π-shaped and T-shaped equivalent circuits in the power system; based on this, in this embodiment, the unified dynamic equation of multi-energy flow transmission after Laplace transform is subjected to branch external port equivalence based on distributed parameter approximation, and the unified dynamic equation of multi-energy flow coupling transformation after Laplace transform is subjected to coupling node external port equivalence based on distributed parameter approximation. The obtained unified multi-energy flow model and the unified multi-energy flow coupling transformation model are the same in form and are both expressed as:

[0123]

[0124] Where, and ε denote the approximation operator, a and b are integral constants determined by the boundary conditions.

[0125] In the embodiment of the present invention, Figure 4 The implementation process of the above steps S4 to S6 is shown.

[0126] In step S4 of the embodiment of the present invention, in the process of constructing a universal matrix multi-energy mass flow network, a branch characteristic matrix Z is defined to represent the relationship between the starting and terminal extension quantities of the energy network branch as shown in formula (21).

[0127]

[0128] The definition of the extensive quantity distribution coefficient matrix D is shown in formula (22). e (0≤d e ≤1) represents the ratio of the starting extension of branch e to the total extension outflowing from the same node.

[0129]

[0130] Based on the branch characteristic matrix, the extensive relationship between the beginning and end of the branch can be expressed as:

[0131] ζ out (s)=Zζ in (s)(23)

[0132] The node equilibrium equation can be expressed as:

[0133]

[0134] Based on this, we can substitute formula (23) into (24) and use replace In step S4 of this embodiment, a universal matrixed dynamic characteristic equation of the multi-energy mass flow network is constructed;

[0135] ζ out (s)=Yζ(s)(25)

[0136] Y=(Z -1 -D(A + ) T A - ) -1 D(A + ) T (26)

[0137] Where Z represents the branch characteristic matrix in the multi-energy mass flow network, D represents the matrix of extensive quantity distribution coefficients, Y represents the energy node admittance matrix, ζ out (s) represents the end extension of the branch characteristic matrix, ζ(s) represents the beginning extension of the branch characteristic matrix, and z e The constant d represents the Laplace operator s of each branch loss and delay. e It represents the ratio of the starting extension of branch e to the total extension of the outflow from the same node, e represents the branch index, and E represents the branch set.

[0138] In step S5 of the embodiment of the present invention, the heterogeneous networks in the multi-energy and mass flow network include an electric power flow network, a thermal flow network, a material flow network, and a hydrogen flow network;

[0139] Calculating heterogeneous network boundary values in a multi-energy flow network includes the following steps:

[0140] S51, dividing the network nodes in the multi-energy mass flow network into key boundary nodes and non-key nodes according to the importance and physical properties of the network nodes;

[0141] Specifically, for key boundary nodes, the changes in the extensive and intensive quantities of such nodes are critical to the system or other systems coupled with it; for example, the busbar connecting the tie line in the power system, the node where the gas generator set is located in the gas grid, etc.

[0142] Non-critical nodes are system nodes other than critical boundary nodes and can be further divided based on specific system characteristics and application requirements; for example, they can be divided based on whether they are connected to critical nodes or whether the intensity / extension is constant.

[0143] S52, performing matrix operations on the node strength and extension injection values according to the divided node types to construct a block matrix;

[0144] In this embodiment, the constructed block matrix is expressed as:

[0145]

[0146] Where Y BB , Y BI , Y IB , Y II represents the block matrix of Y, Y represents the energy node admittance matrix, ψ B (s) and ψ I (s) represents two sets of node strength divided by node type, ζ B (s) and ζ I (s) represents two sets of values injected into the extensive quantity divided by node type;

[0147] S53, performing Gaussian elimination on the constructed block matrix to obtain the boundary equivalent equation of the multi-energy flow network containing only key boundary nodes, and then calculating the boundary equivalent of the heterogeneous network;

[0148] In this embodiment, the boundary equivalence equation is expressed as:

[0149]

[0150] In step S6 of the embodiment of the present invention, drawing on the power system flow calculation method, the green hydrogen metallurgical integrated energy system achieves accurate modeling of multiple energy and mass flows by introducing a unified Jacobian matrix of multiple energy and mass flows.

[0151] The unified Jacobian matrix of the constructed green hydrogen metallurgical integrated energy system is expressed as:

[0152]

[0153] Where, It represents the extensive quantity and intensive quantity characterization of process J in the green hydrogen metallurgical integrated energy system. The subscripts m and n represent the parameter indexes in the green hydrogen metallurgical integrated energy system.

[0154] The unified Jacobian matrix in this embodiment effectively describes the coupling relationship between each node variable and the system state, covering various material flows such as electricity, hydrogen, and thermal energy.

[0155] In the embodiment of the present invention, the above method can accurately capture the complex coupling dynamics in the multi-energy network, thereby providing a reliable calculation basis for the distribution of multiple energy and mass flows, and ultimately realizing the integrated and precise modeling of multiple energy and mass flows of the green hydrogen metallurgical integrated energy system.

[0156] Specific embodiments are used in the present invention to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core ideas. At the same time, for those skilled in the art, according to the ideas of the present invention, there may be changes in the specific implementation methods and application scopes. In summary, the contents of this specification should not be understood as limiting the present invention.

[0157] Those skilled in the art will appreciate that the embodiments described herein are intended to help readers understand the principles of the present invention, and it should be understood that the scope of protection of the present invention is not limited to such specific descriptions and embodiments. Those skilled in the art can make various other specific variations and combinations based on the technical teachings disclosed in the present invention without departing from the essence of the present invention, and such variations and combinations are still within the scope of protection of the present invention.

Claims

1. A multi-energy and mass flow integrated precise modeling method for green hydrogen metallurgical integrated energy system, characterized by: The following steps are involved: S1. Analyze the transmission dynamic characteristics and coupled transformation dynamic characteristics of multiple energy and mass flows in the green hydrogen metallurgical integrated energy system, and construct a transmission characteristic model of multiple energy and mass flows and a coupled transformation process model; the transmission characteristic model of multiple energy and mass flows includes the current carbon flow equation, the thermodynamic carbon flow equation, the hydrogen carbon flow equation, and the material flow equation; The coupled conversion process model of multiple energy and mass flows includes an electric-thermal conversion process model, an electric-hydrogen conversion process model, and a material conversion process model; S2. Using a unified mathematical equation of multiple energy and mass flows based on differential dynamics equations, the transmission characteristic model of multiple energy and mass flows and the coupled transformation process model are expressed as a unified dynamic equation of multiple energy and mass flows transmission and a unified dynamic equation of multiple energy and mass flows coupled transformation, respectively. The unified dynamic equation of multiple energy and mass flows transmission corresponding to the transmission characteristic model and the unified dynamic equation of multiple energy and mass flows coupled transformation corresponding to the coupled transformation process model are identical in form and are both expressed as: Where, represents a generalized intensity quantity, represents an extensive quantity, 、 、 and All represent branch parameters; S3. Perform transmission static algebraic analysis based on Laplace transform and branch external port equivalence based on distributed parameter approximation on the unified dynamic equations of multi-energy and mass flow transmission, and construct a unified model of multi-energy and mass flow; The unified dynamic equations of multi-energy-mass-flow coupled transformation are subjected to the static algebraic analysis of energy-mass conversion based on Laplace transform and the external port equivalence of coupling nodes based on distributed parameter approximation, thus constructing a unified model of multi-energy-mass-flow coupled transformation. S4. Based on the unified model of multiple energy and mass flows and the unified model of multiple energy and mass flow coupling transformation, a universal matrix multi-energy and mass flow network full-network dynamic characteristic equation is constructed; the constructed universal matrix multi-energy and mass flow network full-network dynamic characteristic equation is expressed as: Where, represents the branch characteristic matrix in the multi-energy mass flow network, , represents the extensive quantity distribution coefficient matrix, , represents the energy node admittance matrix, represents the terminal extension of the branch characteristic matrix, represents the initial extension of the branch characteristic matrix, Laplace operator representing the loss and delay of each branch The constant, Indicates a branch The ratio of the initial extension of the node to the total extension of the node flowing out, Indicates the branch index, represents a branch set, Indicates the cross-sectional area of the pipe in the thermal branch; S5. Calculate the heterogeneous network boundary values in the multi-energy mass flow network based on the dynamic characteristic equation of the entire network; S6. Based on the boundary equivalence of heterogeneous networks, a unified Jacobian matrix of the green hydrogen metallurgical integrated energy system is constructed, and the distribution calculation and analysis of multiple energy and mass flows are performed.

2. The multi-energy and mass flow integrated precise modeling method of the green hydrogen metallurgical integrated energy system according to claim 1 is characterized in that: The step S2 is specifically as follows: The physical quantities in the transmission characteristic model and the transformation process model are classified into intensity quantities and extensive quantities. In the unified dynamic equation of multi-energy and mass flow transmission and the unified dynamic equation of multi-energy and mass flow coupling transformation, the spatial differentials of the intensity quantities and the extensive quantities are used to represent the left side of the equal sign, and the time differentials of the intensity quantities and the extensive quantities and related terms are used to represent the right side of the equal sign.

3. The multi-energy and mass flow integrated precise modeling method of the green hydrogen metallurgical integrated energy system according to claim 1 is characterized in that: In step S3, when performing a Laplace transform-based transmission static algebraic analysis on the unified dynamic equation of multi-energy-mass flow transmission, and performing a Laplace transform-based energy-mass conversion static algebraic analysis on the unified dynamic equation of multi-energy-mass flow coupling conversion, they are both expressed in the Laplace domain as: Where, , , represents the Laplace transform operator, complex number represents the Laplace transform parameters; The unified dynamic equation of multi-energy-mass flow transmission after Laplace transformation is equivalent to the branch external port based on the distributed parameter approximation, and the unified dynamic equation of multi-energy-mass flow coupling transformation after Laplace transformation is equivalent to the coupling node external port based on the distributed parameter approximation. The obtained unified model of multi-energy-mass flow and the unified model of multi-energy-mass flow coupling transformation are the same in form and are expressed as: Where, and represents the approximation operator, , and represents the integration constant determined by the boundary conditions.

4. The multi-energy and mass flow integrated precise modeling method of the green hydrogen metallurgical integrated energy system according to claim 1 is characterized in that: In step S5, the heterogeneous networks in the multi-energy and mass flow network include an electric power flow network, a thermal flow network, a material flow network, and a hydrogen flow network; Calculating heterogeneous network boundary values in a multi-energy flow network includes the following steps: S51, dividing the network nodes in the multi-energy mass flow network into key boundary nodes and non-key nodes according to the importance and physical properties of the network nodes; S52, performing matrix operations on the node strength and extension injection values according to the divided node types to construct a block matrix; S53. Perform Gaussian elimination on the constructed block matrix to obtain the boundary equivalent equation of the multi-energy flow network that only contains key boundary nodes, and then calculate the boundary equivalent of the heterogeneous network.

5. The multi-energy and mass flow integrated precise modeling method for the green hydrogen metallurgical integrated energy system according to claim 4 is characterized in that: In step S52, the constructed block matrix is expressed as: Where, , , , express The block matrix, represents the energy node admittance matrix, and It represents two sets of node strength divided by node type. and Indicates that the extensive quantity injection value is divided into two sets according to the node type; In step S53, the boundary equivalence equation is expressed as: 。 6. The multi-energy and mass flow integrated precise modeling method of the green hydrogen metallurgical integrated energy system according to claim 1 is characterized in that: In step S6, the unified Jacobian matrix of the constructed green hydrogen metallurgical integrated energy system is expressed as: Where, Represents the green hydrogen metallurgical integrated energy system process The extensive and intensive characterization of m and n Represents the parameter index in the green hydrogen metallurgical integrated energy system.

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