Multi-energy mass flow integrated accurate modeling method of green hydrogen metallurgy comprehensive energy system

Abstract

The invention discloses a multi-energy mass flow integrated accurate modeling method of a green hydrogen metallurgy comprehensive energy system. Firstly, a multi-energy mass flow transmission unified mathematical equation based on differential dynamics is provided for a green hydrogen metallurgy comprehensive energy system aiming at the problems that transmission characteristics of heterogeneous energy flow and material flow are large in difference and difficult to describe in a unified mode. Secondly, in order to simplify a complex dynamic problem, time domain dynamic is converted into a static algebraic problem, and a generalized transmission model based on distribution parameters is constructed; for the challenge of multi-energy mass flow branch and node distribution parameter isomerism, an equivalent modeling method of branch and node external ports is further provided, and a description system of multi-energy mass flow integrated modeling is perfected. And finally, based on the algebraic model, the matrix modeling of the multi-energy-mass-flow network is researched, a standardized matrix analysis normal form is provided, and the rapid calculation of the multi-energy-mass-flow distribution is realized by constructing a unified Jacobian matrix, so that accurate support is provided for the multi-link cooperative regulation and control of the system.

Description

Technical Field

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

[0002] As the world pursues the goal of carbon neutrality, the steel industry, as a traditional high-emission industry, faces tremendous pressure to reduce emissions. Green hydrogen metallurgy, as a technology that replaces carbon-based reducing agents with hydrogen, is gradually becoming an important path for clean metallurgy in the future. This technology produces hydrogen through the electrolysis of water, uses green hydrogen as a reducing agent, reduces carbon emissions in the smelting process, and achieves a deep integration of clean energy and steel production. To ensure the efficient operation of the green hydrogen metallurgical integrated energy system, accurate modeling and system optimization become the key. However, faced with the complex energy and mass flow and multi-energy flow coupling characteristics in metallurgical processes, how to achieve unified modeling of the system remains a major challenge.

[0003] At present, existing research has made some progress in modeling the coupling relationship between material flow and energy flow, especially for the study of traditional steel process flow. The existing models mainly focus on the interaction between material flow properties and energy flow, and construct an analytical method for energy and mass flow distribution under steady-state conditions. Most of these models are oriented to 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 the 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, the current models are mostly based on steady-state analysis and cannot fully consider the dynamic change characteristics of multiple energy flows in time and space. In particular, the existing models have great limitations in dealing with the unification of transient characteristics of electricity and steady-state characteristics of material flows. Secondly, the existing models mainly focus on the conversion of a single energy and mass flow 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, the differences in time granularity and spatial distribution will cause the ill-posed problem 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 view of the above-mentioned deficiencies in the prior art, the multi-energy-mass-flow integrated precise modeling method of the green hydrogen metallurgical comprehensive 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 comprehensive energy system.

[0006] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is: a multi-energy-mass-flow integrated accurate modeling method for a 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 the 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 coupling 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 coupling transformation respectively;

[0009] S3. The unified dynamic equations of multi-energy mass flow transmission are subjected to transmission static algebraic analysis based on Laplace transform and branch external port equivalence based on distributed parameter approximation in turn, and a unified model of multi-energy mass flow is constructed;

[0010] The unified dynamic equation of multi-energy-mass-flow coupling transformation is subjected to the static algebraic analysis of energy-mass conversion based on Laplace transform and the equivalent of the coupling node external port based on the distributed parameter approximation, and a unified model of multi-energy-mass-flow coupling transformation is constructed.

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

[0012] S5. Calculate the boundary equivalence of heterogeneous networks in the multi-energy mass flow network according to the dynamic characteristic equation of the whole network of the multi-energy mass flow network;

[0013] S6. Based on the boundary values ​​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.

[0014] Further, in step S1, the transmission characteristic model of the multi-energy-mass flow 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 kinetic equation of multi-energy and mass flow transmission and the unified kinetic equation of multi-energy and mass flow coupled 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 coupling transformation process model are the same 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 all represent branch parameters.

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

[0022]

[0023]

[0024] 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;

[0025] 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:

[0026] ψ(x,s)=a exp(lx)+b exp(-lx)

[0027]

[0028] In the formula, l and ε represent approximate operators, a and b are integration constants determined by boundary conditions.

[0029] Furthermore, in step S4, the constructed universal matrix multi-energy mass flow network full network dynamic characteristic equation is expressed as:

[0030] ζ out (s) = Yζ(s)

[0031] Y=(Z -1 -D(A + ) 晻 A - ) -1 D(A + )

[0032] 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 outflowing from the same node, e represents the branch index, and E represents the branch set.

[0033] Further, 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;

[0034] Calculating heterogeneous network boundary values ​​in a multi-energy flow network includes the following steps:

[0035] 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;

[0036] S52, performing matrix operations on the node strength and extension injection values ​​according to the divided node types to construct a block matrix;

[0037] S53. Perform Gaussian elimination on the constructed block matrix to obtain the boundary equivalence equation of the multi-energy flow network that only contains key boundary nodes, and then calculate the boundary equivalence of the heterogeneous network.

[0038] Furthermore, in step S52, the constructed block matrix is ​​expressed as:

[0039]

[0040] 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 quantities divided according to node types, ζ B (s) and ζ I (s) represents two sets of values ​​injected into the extensive quantity divided according to the node type;

[0041] In step S53, the boundary equivalent equation is expressed as:

[0042]

[0043] Furthermore, in step S6, the unified Jacobian matrix of the constructed green hydrogen metallurgical integrated energy system is expressed as:

[0044]

[0045] In the formula, It represents the extensive and intensive quantity characterization of process J in the green hydrogen metallurgical integrated energy system. The subscripts m and n represent the parameter index in the green hydrogen metallurgical integrated energy system.

[0046] The beneficial effects of the present invention are:

[0047] (1) The present invention discloses a method for accurate modeling of integrated multi-energy and mass flows in a green hydrogen metallurgical integrated energy system. First, by focusing on the green hydrogen metallurgical integrated energy system, a unified mathematical equation for multi-energy and mass flow transmission based on differential dynamics is proposed to address the problem that the transmission characteristics of heterogeneous energy flows and material flows are greatly different and difficult to describe in a unified manner. Secondly, in order to simplify complex dynamic problems, the time domain dynamics are converted into static algebraic problems, 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, which improves the description system of integrated modeling of multi-energy and mass flows. Finally, based on the above-mentioned algebraic model, the matrix modeling of multi-energy and mass flow networks is studied, a standardized matrix analysis paradigm is proposed, and by constructing a unified Jacobian matrix, the rapid calculation of multi-energy and mass flow distribution is realized, providing precise support for the coordinated regulation of multiple links in the system.

[0048] (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.

[0049] (3) The present invention proposes an innovative modeling method that uses differential dynamics to uniformly describe the transmission characteristics of heterogeneous energy flows and material flows, solving the problem that traditional modeling methods cannot simultaneously handle the differences in transient characteristics of power and steady-state characteristics of material flows, thereby achieving accurate modeling of the integration of multiple energy and material flows in the green hydrogen metallurgical integrated energy system.

[0050] (4) The present invention innovatively transforms the complex dynamic coupling of multiple energy and mass flows into a static algebraic problem through an algebraic approach, and realizes the rapid distributed calculation and analysis of the multiple energy and mass flow network by constructing a unified Jacobian matrix, thereby simplifying the regulation and optimization process of the multiple energy and mass flow system and improving the computational efficiency and accuracy of the integrated energy system. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 Flowchart of the multi-energy-mass-flow integrated precise modeling method for the green hydrogen metallurgical integrated energy system provided by the present invention.

[0052] Figure 2 A schematic diagram of a framework for constructing a unified multi-energy-mass flow model provided by the present invention.

[0053] Figure 3 A schematic diagram of the framework for constructing a unified model for coupling transformation of multiple energy and mass flows provided by the present invention.

[0054] Figure 4 Schematic diagram of the integrated distribution and calculation framework of energy and mass flow realized by the multi-energy and mass flow network provided by the present invention. DETAILED DESCRIPTION

[0055] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0056] The embodiment of the present invention provides a multi-energy-mass-flow integrated accurate modeling method for a green hydrogen metallurgical integrated energy system, such as Figure 1 As shown, the following steps are included:

[0057] 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 the transmission characteristic model and coupled transformation process model of multiple energy and mass flows;

[0058] S2. Using the unified mathematical equation of multi-energy-mass flow based on differential dynamics equation, the transmission characteristic model and coupling 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 coupling transformation respectively;

[0059] S3. The unified dynamic equations of multi-energy mass flow transmission are subjected to transmission static algebraic analysis based on Laplace transform and branch external port equivalence based on distributed parameter approximation in turn, and a unified model of multi-energy mass flow is constructed;

[0060] The unified dynamic equation of multi-energy-mass-flow coupling transformation is subjected to the static algebraic analysis of energy-mass conversion based on Laplace transform and the equivalent of the coupling node external port based on the distributed parameter approximation, and a unified model of multi-energy-mass-flow coupling transformation is constructed.

[0061] S4. Based on the unified model of multi-energy mass flow and the unified model of multi-energy mass flow coupling transformation, a universal matrix multi-energy mass flow network full network dynamic characteristic equation is constructed;

[0062] S5. Calculate the boundary equivalence of heterogeneous networks in the multi-energy mass flow network according to the dynamic characteristic equation of the whole network of the multi-energy mass flow network;

[0063] S6. Based on the boundary values ​​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.

[0064] In step S1 of the embodiment of the present invention, the transmission characteristic model of the multi-energy-mass flow includes the current (carbon) flow equation, the thermodynamic (carbon) flow equation, the hydrogen (carbon) flow equation and the material flow equation, specifically;

[0065] Current (carbon) flow equation:

[0066] Power flow refers to the electric power transmitted along the power line, that is, the power flow, which is the basic object of power system research. The transmission of AC power flow satisfies Maxwell's equations. Generally, it can be considered that the transmission line medium is uniform. The classic mathematical equation is:

[0067]

[0068] Where U and I are the voltage and current of the power flow at the transmission line position x at time t, respectively; R and L are the branch resistance and reactance per unit length, respectively; G and C are the ground admittance and capacitance per unit length, respectively.

[0069] The essence of the carbon emission flow of the power system is to quantitatively determine the flow state of carbon emissions through the power flow distribution, so as to track the source and destination of carbon emissions. The carbon emission flow depends on the existence of the 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 output of the power source and are less affected by the reactive 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 established through formula (1).

[0070] Thermodynamic (carbon) flow equation:

[0071] Thermal flow refers to the heat power transmitted along the heat network. The transfer of heat in the heat network is a composite process of heat migration caused by the movement of the working medium carrier and heat exchange between the pipe network and the environment. The transfer of heat in a one-dimensional pipe is manifested as the change of water temperature at different positions x with t. The mathematical equation is:

[0072]

[0073] 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 diffusion coefficient of the heat flux; A is the cross-sectional area of ​​the pipeline of the thermal branch.

[0074] The first and second items on the left side of the equal sign in the formula represent the heat conduction of forced convection, the third item on the left side of the equal sign represents the static heat conduction inside the heat flux carrier, and the fourth item on the left side of the equal sign represents the heat loss during the transmission process. Since the thermal conductivity of the heat flux carrier is usually very low, about 0.59W / mK, which is much smaller than the thermal conductivity of common metals (the thermal conductivity of copper is 403W / mK, and the thermal conductivity of iron is 86.5W / mK), the static heat conduction inside the heat flux carrier can usually be ignored, and formula (2) can be simplified to:

[0075]

[0076] Let the heat flow power φ represent the heat that can be released by the pipe heat flow through the cross section 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 the low-temperature heat source after releasing heat). According to the definition of specific heat capacity:

[0077] φ=cmT (4)

[0078] In addition, the primary heat network in the thermal system generally adopts the 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:

[0079]

[0080] Similar to the electricity (carbon) flow, in the heat transmission network, the carbon emission flow depends on the transmission path of the heat flow, so the distribution of the heat flow directly affects the flow of carbon emissions. In the green hydrogen integrated energy system, the carbon emission flows of the heat and power transmission networks are analyzed through similar mechanisms. Therefore, the interdependence of carbon flow and heat flow makes the thermal (carbon) flow equation in the system uniformly modeled using formula (5) to ensure accurate calculation of the carbon emission flow in the thermal network.

[0081] Hydrogen (carbon) flow equation:

[0082] Since hydrogen in the green hydrogen metallurgical system is mainly obtained by electrolysis of water, and hydrogen is used as a reducing agent for iron oxide to achieve metal smelting, the transmission process of hydrogen in the gas network can be equivalent to energy flow. Ignoring the temperature and height changes of the hydrogen pipeline, the hydrogen flow obeys the law of conservation of mass and the Bernoulli law of non-ideal gases, and the pressure and flow change along the way. The mathematical equation is:

[0083]

[0084] 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 (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.

[0085] The partial derivative of the flow rate with respect to time in formula (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 water electrolysis equipment, the partial derivative of the flow rate with respect to time is ignored, and equations (6) and (7) are approximated as:

[0086]

[0087] 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 prepared by electrolysis of water and used as a reducing agent in the smelting process of iron oxide to achieve metal refining. Since the hydrogen transmission process 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.

[0088] Material flow equation:

[0089] Since the green hydrogen metallurgical system mainly heats iron ore through electromagnetic induction during the electromagnetic furnace heating process, the change of the magnetic field will generate eddy currents in the iron ore, which will lead to material flow. The change of material flow can be equivalent to the flow of magnetic flux and frequency. Ignoring the temperature gradient and height difference of the iron ore, the material flow obeys the law of conservation of energy and Faraday's law of electromagnetic induction. The magnetic flux and frequency change with time and space, and the equation is:

[0090]

[0091] Where: is the magnetic flux difference at position x at time t; f h and f m They represent the changes of 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 of 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.

[0092] 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;

[0093] Electric-heat conversion process model:

[0094] In 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:

[0095]

[0096] Where: 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, describing 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.

[0097] Secondly, the coupling of the electromagnetic field to the material flow is described by the following equation:

[0098]

[0099] In the formula: 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.

[0100] Electricity-hydrogen conversion process model:

[0101] In the green hydrogen metallurgical system, the generation and transmission of hydrogen involves the dynamic process of water electrolysis and hydrogen diffusion. Ignoring the temperature and pressure changes in the system, the change of hydrogen concentration over time and space can be described by the following time-space differential equation:

[0102]

[0103] 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, describing 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.

[0104] In addition, the relationship between current density J and electric field strength E can be expressed by the conductivity equation:

[0105] J=σE(13)

[0106] 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.

[0107] This equation describes the generation and diffusion of hydrogen in a green hydrogen metallurgical system under the action of an electric field. The hydrogen produced by water electrolysis is transmitted in the system by diffusion, while the electric field drives the current, affecting the transmission rate and spatial distribution of hydrogen. This process is closely related to the coupling between the electric field and material flow.

[0108] Models of material transformation processes;

[0109] In the green hydrogen metallurgical system, hydrogen acts as a reducing agent to react with iron oxide in iron ore to achieve iron smelting. Ignoring the temperature and pressure changes in the system, the changes in the concentration of hydrogen and iron over time and space can be described by the following time-space differential equations:

[0110]

[0111] 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, describing 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.

[0112] In this embodiment, the above equation (14) represents the transmission and reaction process of hydrogen. Hydrogen not only diffuses in the space, but also reacts with iron oxide, resulting in a decrease in hydrogen concentration. Equation (15) describes the generation process of iron. The concentration of iron is not only affected by the diffusion of iron, but also by the reduction of iron oxide by hydrogen to generate iron, and may react with hydrogen for a secondary time after generation.

[0113] Equations (14) and (15) together describe the reaction mechanism of hydrogen and iron oxide, taking into account both the transport of substances and the effect of chemical reactions on the concentrations of hydrogen and iron, thereby constructing a detailed model of substance flow and transformation in the green hydrogen metallurgical system.

[0114] Step S2 in the embodiment of the present invention is specifically as follows:

[0115] 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 kinetic equation of multi-energy and mass flow transmission and the unified kinetic 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.

[0116] Specifically, in the present embodiment, in the above-mentioned transmission characteristic model, the electric power (carbon) flow equation, the thermal (carbon) flow equation, the hydrogen (carbon) flow equation and the material flow equation have 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 thermal grid, and the pressure change Δπ in the gas grid; extensive quantities change 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 thermal 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, with the left side of the equation containing the spatial differentials of the intensive quantity and the extensive quantity, and the right side consisting of the time differentials of the intensive quantity and the extensive quantity and related terms.

[0117] 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 coupling transformation process model are the same in form, and are both expressed as:

[0118]

[0119] Where ψ represents the generalized intensity quantity, ζ represents the extension quantity, and α1, α2, β1 and β2 all represent branch parameters;

[0120] In step S3 of the embodiment of the present invention, Figure 2 As shown, based on the unified dynamic equation of multi-energy mass flow constructed in the above step S2, the transmission static algebraic analysis and branch external port equivalence are performed in turn; 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.

[0121] Specifically, in this embodiment, the research on the green hydrogen metallurgical multi-energy system mainly focuses on the mutual influence caused by "change" 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 the transmission static algebraic analysis based on Laplace transform is performed on the unified dynamic equation of multi-energy flow transmission, and the energy-mass conversion static algebraic analysis based on Laplace transform is performed on the unified dynamic equation of multi-energy flow coupling conversion, it is expressed in the Laplace domain as:

[0122]

[0123] Wherein, 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.

[0124] In this embodiment, through the above-mentioned Laplace transform, the distributed parameter circuit in the time domain can be simplified to a Laplace domain distributed parameter circuit containing only spatial differentials, and the resistance, inductance and capacitance are uniformly represented. However, the distributed parameter circuit is still difficult to analyze directly, so it is necessary to further simplify or approximate it to 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 equivalent 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 mass flow transmission after Laplace transformation is equivalent to the branch external port based on 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 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:

[0125] ψ(x,s)=a exp(lx)+bexp(-lx) (19)

[0126]

[0127] In the formula, l and ε represent approximate operators, a and b are integration constants determined by boundary conditions.

[0128] In the embodiment of the present invention, Figure 4 The implementation process of the above steps S4 to S6 is shown.

[0129] In step S4 of the embodiment of the present invention, in the process of constructing a universal matrixed 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).

[0130]

[0131] The extensive quantity distribution coefficient matrix D is defined as 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.

[0132]

[0133] Based on the branch characteristic matrix, the extensive relationship between the beginning and end of the branch can be expressed as:

[0134] ζ out (s)=Zζ in (s)(23)

[0135] The node equilibrium equation can be expressed as:

[0136]

[0137] Based on this, we substitute equation (23) into (24) and use replace In step S4 of this embodiment, a general matrixed dynamic characteristic equation of the multi-energy mass flow network is constructed;

[0138] ζ out (s) = Yζ(s)(25)

[0139] Y=(Z -1 -D(A + ) 晻 A - ) -1 D(A + ) (26)

[0140] 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 outflowing from the same node, e represents the branch index, and E represents the branch set.

[0141] 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;

[0142] Calculating heterogeneous network boundary values ​​in a multi-energy flow network includes the following steps:

[0143] 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;

[0144] 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 busbars connecting the tie lines in the power system, the nodes where the gas generator sets are located in the gas grid, etc.

[0145] For non-critical nodes, such nodes are system nodes other than critical boundary nodes, and can be further divided according to specific system characteristics and application requirements; for example, they can be divided according to whether they are connected to critical nodes, or whether the intensity / extension quantity is constant, etc.;

[0146] S52, performing matrix operations on the node strength and extension injection values ​​according to the divided node types to construct a block matrix;

[0147] In this embodiment, the constructed block matrix is ​​expressed as:

[0148]

[0149] 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 quantities divided according to node types, ζ B (s) and ζ I (s) represents two sets of values ​​injected into the extensive quantity divided according to the node type;

[0150] S53, performing Gaussian elimination on the constructed block matrix to obtain the boundary equivalent equation of the multi-energy mass flow network containing only the key boundary nodes, and then calculating the boundary equivalent of the heterogeneous network;

[0151] In this embodiment, the boundary equivalence equation is expressed as:

[0152]

[0153] 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 realizes accurate modeling of multiple energy and mass flows by introducing a unified Jacobian matrix of multiple energy and mass flows.

[0154] The unified Jacobian matrix of the constructed green hydrogen metallurgical integrated energy system is expressed as:

[0155]

[0156] In the formula, It represents the extensive and intensive quantity characterization of process J in the green hydrogen metallurgical integrated energy system. The subscripts m and n represent the parameter index in the green hydrogen metallurgical integrated energy system.

[0157] 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.

[0158] 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 finally realizing the integrated and precise modeling of multiple energy and mass flows of the green hydrogen metallurgical integrated energy system.

[0159] The present invention uses specific embodiments 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 idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

[0160] 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 should be understood that the protection scope of the present invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific variations and combinations that do not deviate from the essence of the present invention based on the technical revelations disclosed by the present invention, and these variations and combinations are still within the protection scope of the present invention.

Claims

1. A multi-energy-mass-flow integrated accurate 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 the transmission characteristic model and coupled transformation process model of multiple energy and mass flows; S2. Using the unified mathematical equation of multi-energy-mass flow based on differential dynamics equation, the transmission characteristic model and coupling 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 coupling transformation respectively; S3. The unified dynamic equations of multi-energy mass flow transmission are subjected to transmission static algebraic analysis based on Laplace transform and branch external port equivalence based on distributed parameter approximation in turn, and a unified model of multi-energy mass flow is constructed; The unified dynamic equation of multi-energy-mass-flow coupling transformation is subjected to the static algebraic analysis of energy-mass conversion based on Laplace transform and the equivalent of the coupling node external port based on the distributed parameter approximation, and a unified model of multi-energy-mass-flow coupling transformation is constructed. S4. Based on the unified model of multi-energy mass flow and the unified model of multi-energy mass flow coupling transformation, a universal matrix multi-energy mass flow network full network dynamic characteristic equation is constructed; S5. Calculate the boundary equivalence of heterogeneous networks in the multi-energy mass flow network according to the dynamic characteristic equation of the whole network of the multi-energy mass flow network; S6. Based on the boundary values ​​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-mass-flow integrated precise modeling method for the green hydrogen metallurgical comprehensive energy system according to claim 1 is characterized in that: In the step S1, the transmission characteristic model of the multi-energy and mass flow includes an electric current (carbon) flow equation, a thermodynamic (carbon) flow equation, a hydrogen (carbon) flow equation and a 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.

3. The multi-energy-mass-flow integrated precise modeling method for the green hydrogen metallurgical comprehensive 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 kinetic equation of multi-energy and mass flow transmission and the unified kinetic equation of multi-energy and mass flow coupled 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.

4. The multi-energy-mass-flow integrated precise modeling method for the green hydrogen metallurgical comprehensive energy system according to claim 1 is characterized in that: 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 coupling transformation process model are the same in form and are both expressed as: Where ψ represents the generalized intensity quantity, ζ represents the extension quantity, and α1, α2, β1 and β2 all represent branch parameters.

5. The multi-energy-mass-flow integrated precise modeling method for the green hydrogen metallurgical comprehensive energy system according to claim 4 is characterized in that: In step S3, when the transmission static algebraic analysis based on Laplace transform is performed on the unified dynamic equation of multi-energy-mass flow transmission, and when the energy-mass conversion static algebraic analysis based on Laplace transform is performed on the unified dynamic equation of multi-energy-mass flow coupling conversion, they are expressed in the Laplace domain as: 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; 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: ψ(x,s)=aexp(lx)+bexp(-lx) In the formula, l and ε represent approximate operators, a and b are integration constants determined by boundary conditions.

6. The multi-energy-mass-flow integrated precise modeling method based on the green hydrogen metallurgical comprehensive energy system according to claim 1 is characterized in that: In step S4, the constructed universal matrix multi-energy mass flow network full network dynamic characteristic equation is expressed as: g out (s)=Yζ(s) Y = (Z -1 - D(A + ) ⊙ A - ) -1 D(A + ) It should be noted that the symbols " -1 ", " + ", " - ", " -1 ", " + " are not standard mathematical or common symbols. If they have specific meanings in a particular context, the translation might need to be adjusted accordingly. Also, the symbol "晻" is not recognized. I've assumed it might be a special symbol that should be translated as "⊙" based on the pattern. If this is incorrect, please provide more context. Where Z represents the branch characteristic matrix in the multi-energy mass flow network, Z = diag[z e ] |E|×|E| , D represents the matrix of extensive distribution coefficients, D = diag[d e ] |E|×|E| , 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 outflowing from the same node, e represents the branch index, and E represents the branch set.

7. The multi-energy-mass-flow integrated precise modeling method for the green hydrogen metallurgical comprehensive 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; The calculation of heterogeneous network boundary isovalues ​​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 equivalence equation of the multi-energy flow network that only contains key boundary nodes, and then calculate the boundary equivalence of the heterogeneous network.

8. The multi-energy-mass-flow integrated precise modeling method for the green hydrogen metallurgical comprehensive energy system according to claim 7 is characterized in that: In step S52, the constructed block matrix is ​​expressed as: 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 quantities divided according to node types, ζ B (s) and ζ I (s) represents two sets of values ​​injected into the extensive quantity divided according to the node type; In step S53, the boundary equivalent equation is expressed as:

9. The multi-energy-mass-flow integrated precise modeling method for the green hydrogen metallurgical comprehensive 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: In the formula, It represents the extensive and intensive quantity characterization of process J in the green hydrogen metallurgical integrated energy system. The subscripts m and n represent the parameter index in the green hydrogen metallurgical integrated energy system.

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