Flexibility Evaluation Method for the Energy Supply System of Steel Plants Considering Privacy Protection and Load Uncertainty

Abstract

The present invention provides a method for evaluating the flexibility of an energy supply system in a steel plant considering privacy protection and load uncertainty, including: constructing a description model of the energy supply system based on the equipment parameters of the energy supply system of the steel plant to be evaluated; obtaining the aggregated flexible domains of the energy supply equipment provided by each plant area, and constructing a first coupling relationship between the fuel subsystem and the steam subsystem in the energy supply system and a second coupling relationship between the steam subsystem and the power subsystem in the energy supply system based on the aggregated flexible domains and the description model; constructing constraint conditions based on the first coupling relationship and the second coupling relationship, and solving the flexibility evaluation objective function based on the constraint conditions to obtain the flexibility evaluation result of the energy supply system, where the flexibility evaluation result reflects the regulation ability of the energy supply system, and the uncertainties of the steam and power loads of the steel plant to be evaluated are the uncertainty parameters in the flexibility evaluation objective function. The present invention simultaneously considers privacy protection and load uncertainty, and can achieve safe and accurate flexibility evaluation.

Description

Technical Field

[0001] The present invention relates to the technical field of power grid peak regulation, and particularly to a method for evaluating the flexibility of an energy supply system in a steel plant considering privacy protection and load uncertainty. Background Art

[0002] As a high-energy-consuming industry, a steel plant consumes a large amount of electric energy during its operation, and thus is often restricted by various aspects such as the power supply capacity of the power grid and its own power plant. When the external power grid or its own power plant supplies power to it, there are often certain fluctuations. For example, when the power grid restricts power, some electrical loads in the plant area should operate at a reduced power. To ensure that the electrical load in the steel production process deeply participates in the power grid peak regulation and at the same time improve the overall efficiency of the production system as much as possible, it is necessary to model the steel production process and perform flexible regulation on it.

[0003] Accurately evaluating its own flexibility is the premise and foundation for a steel plant to correctly select and participate in power auxiliary services. At present, there have been works on evaluating the flexibility of the energy supply system in a steel plant. However, the production process of a steel plant is long, and the energy supply system covers various coupled networks such as electricity, steam, and gas. Its regulation ability is subject to multiple constraints, and it is difficult to simply evaluate its flexibility by superimposing the equipment capabilities. At the same time, the differences in material properties and the uncertainty of transmission delay will cause uncertainties in both production electricity and steam loads, affecting the accuracy of the evaluation of the flexibility of the energy supply system. In addition, the information of each plant area in the steel plant is not completely transparent, and the evaluation of the flexibility of the energy supply system requires the joint cooperation of multiple plant areas. The sharing of information may lead to the leakage of equipment operation parameters, thereby damaging the interests of each plant area. The prior art does not consider the issues of uncertainty and privacy protection in the evaluation of the flexibility of the energy supply system in a steel plant, resulting in inaccurate evaluation results of the flexibility of the energy supply system in a steel plant and a risk of information leakage. Summary of the Invention

[0004] The present invention provides a method for evaluating the flexibility of an energy supply system in a steel plant considering privacy protection and load uncertainty, so as to solve the problems of low accuracy and information leakage risk in the prior art for evaluating the flexibility of the energy supply system in a steel plant, and realize the safe and accurate evaluation of the flexibility of the energy supply system in a steel plant.

[0005] The present invention provides a method for evaluating the flexibility of an energy supply system in a steel plant considering privacy protection and load uncertainty, and the method includes:

[0006] Constructing a description model of the energy supply system based on the equipment parameters of the energy supply system of the steel plant to be evaluated, where the description model includes a steam network description sub-model, a power balance constraint description sub-model of the power subsystem, a steam enthalpy value description sub-model, and an operation description sub-model of the energy supply equipment in the energy supply system;

[0007] Obtain the aggregated flexible domain of the energy supply equipment provided by each plant area of the steel plant to be evaluated. Based on the aggregated flexible domain and the description model, construct the first coupling relationship between the fuel subsystem and the steam subsystem in the energy supply system and the second coupling relationship between the steam subsystem and the power subsystem in the energy supply system. The aggregated flexible domain of the energy supply equipment is obtained by aggregating the flexible domains of the same type of energy supply equipment;

[0008] Construct constraint conditions based on the first coupling relationship and the second coupling relationship, and solve the flexibility evaluation objective function based on the constraint conditions to obtain the flexibility evaluation result of the energy supply system. The flexibility evaluation result reflects the regulation ability of the energy supply system. The flexibility evaluation objective function is constructed based on the operation baseline data of the energy supply equipment. The operation baseline data of the energy supply equipment is obtained based on the historical operation data of the energy supply equipment. The uncertainty of the steam and power loads of the steel plant to be evaluated is the uncertainty parameter in the flexibility evaluation objective function.

[0009] According to a method for evaluating the flexibility of an energy supply system of a steel plant considering privacy protection and load uncertainty provided by the present invention, the energy supply equipment includes a gas holder, a boiler, a steam turbine, and a bypass valve. The steam turbine includes a back-pressure steam turbine and a condensing steam turbine.

[0010] According to a method for evaluating the flexibility of an energy supply system of a steel plant considering privacy protection and load uncertainty provided by the present invention, the first coupling relationship is:

[0011] ;

[0012] The second coupling relationship is:

[0013] ;

[0014] Wherein, represents the number of layers of the steam network, represents the change in enthalpy when the steam in the i-th layer of the steam network flows through the boiler, is the operating state of each boiler in the i-th layer of the steam network, , represents the aggregated flexible domain of all boilers in the i-th layer of the steam network, represents the operating state of each condensing steam turbine in the i-th layer, represents the energy utilization efficiency of the boiler in the i-th layer of the steam network, represents the number of types of gas, represents the calorific value of the i-th type of gas, represents the operating state of the gas holder of the i-th type of gas, , The aggregated flexible region of the gas holder for the i-th type of gas , The aggregated flexible region of the condensing steam turbine in the i-th layer of the steam network Indicates the operating status of each back-pressure steam turbine between the i-th layer and the j-th layer of the steam network , The aggregated flexible region of the back-pressure steam turbine between the i-th layer and the j-th layer of the steam network Indicates the operating status of each bypass valve between the i-th layer and the j-th layer of the steam network , The aggregated flexible region of the bypass valve between the i-th layer and the j-th layer of the steam network Indicates the steam load of the i-th layer of the steam network

[0015] According to a method for evaluating the flexibility of an energy supply system in a steel plant considering privacy protection and load uncertainty provided by the present invention, the flexibility evaluation objective function is:

[0016] ;

[0017] Among them, The solution result of is the flexibility evaluation result Indicates the adjustable capacity of the energy supply system at time t of the regulation ability , , Are variables of the flexibility evaluation objective function Is the operating status of each energy supply device at time t Indicates the uncertainty of the steam load Indicates the uncertainty of the power load , Are auxiliary parameters representing the conversion relationship between steam flow and power generation output , , Indicates the efficiency of the condensing steam turbine in the i-th layer of the steam network Indicates the efficiency of the back-pressure steam turbine between the i-th layer and the j-th layer of the steam network , Respectively indicate the enthalpy values of the steam in the i-th layer and the j-th layer of the steam network Indicates the enthalpy value of the saturated steam excluding the steam network Indicates the operating baseline data of the steam turbine in the i-th layer of the steam network Indicates the operating baseline data of the back-pressure steam turbine between the i-th layer and the j-th layer of the steam network Indicates the uncertainty of the steam load of the i-th layer of the steam network

[0018] A flexibility evaluation method for an energy supply system in a steel plant considering privacy protection and load uncertainty. Solving the flexibility evaluation objective function based on the constraint conditions to obtain the flexibility evaluation result of the energy supply system, including:

[0019] Based on the historical data of the steam and power loads of the steel plant to be evaluated, determine the uncertainty confidence intervals of the steam and power loads of the steel plant to be evaluated;

[0020] Based on the uncertainty confidence intervals, determine the range of uncertainty budget values. Based on the operation baseline data and the range of uncertainty budget values, obtain the flexibility evaluation results under different uncertainty budgets. The uncertainty budget reflects the conservativeness of the flexibility evaluation results.

[0021] A flexibility evaluation method for an energy supply system in a steel plant considering privacy protection and load uncertainty. After solving the flexibility evaluation objective function based on the constraint conditions to obtain the flexibility evaluation result of the energy supply system, it includes:

[0022] Based on the operating states of the energy supply devices in the energy supply system corresponding to the flexibility evaluation results, determine the raw material consumption cost and the equipment life loss cost;

[0023] Based on the raw material consumption cost and the equipment life loss cost, determine the regulation cost corresponding to the flexibility evaluation result.

[0024] The present invention also provides a flexibility evaluation device for an energy supply system in a steel plant considering privacy protection and load uncertainty. The device includes:

[0025] A description model construction module, used to construct a description model of the energy supply system based on the equipment parameters of the energy supply system of the steel plant to be evaluated. The description model includes a steam network description sub-model, a power balance constraint description sub-model of the power subsystem, a steam enthalpy value description sub-model, and an operation description sub-model of the energy supply device in the energy supply system;

[0026] A flexible domain aggregation module, used to obtain the aggregated flexible domains of the energy supply devices provided by each plant area of the steel plant to be evaluated. Based on the aggregated flexible domains and the description model, construct the first coupling relationship between the fuel subsystem and the steam subsystem and the second coupling relationship between the steam subsystem and the power subsystem in the energy supply system. The aggregated flexible domains of the energy supply devices are obtained by aggregating the flexible domains of the same type of energy supply devices;

[0027] An optimization solution module is configured to construct constraint conditions based on the first coupling relationship and the second coupling relationship, solve a flexibility evaluation objective function based on the constraint conditions, and obtain a flexibility evaluation result of the energy supply system. The flexibility evaluation result reflects the regulation ability of the energy supply system. The flexibility evaluation objective function is constructed based on the operation baseline data of the energy supply equipment, and the operation baseline data of the energy supply equipment is obtained based on the historical operation data of the energy supply equipment. The uncertainty of the steam and power loads of the steel plant to be evaluated is the uncertainty parameter in the flexibility evaluation objective function.

[0028] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the flexibility evaluation method of the steel plant energy supply system considering privacy protection and load uncertainty as described in any one of the above is implemented.

[0029] The present invention also provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the flexibility evaluation method of the steel plant energy supply system considering privacy protection and load uncertainty as described in any one of the above is implemented.

[0030] The present invention also provides a computer program product, including a computer program. When the computer program is executed by a processor, the flexibility evaluation method of the steel plant energy supply system considering privacy protection and load uncertainty as described in any one of the above is implemented.

[0031] The flexibility evaluation method of the steel plant energy supply system considering privacy protection and load uncertainty provided by the present invention first constructs a description model for describing the energy supply system, obtains the aggregated flexible domains of each energy supply device provided by each plant area, constructs a first coupling relationship between the fuel subsystem and the steam subsystem in the energy supply system and a second coupling relationship between the steam subsystem and the power subsystem in the energy supply system based on the aggregated flexible domains, constructs constraint conditions based on the first coupling relationship and the second coupling relationship, and solves the flexibility evaluation objective function based on the constraint conditions and the description model to obtain the flexibility evaluation result of the energy supply system. The flexibility evaluation objective function includes the operation baseline data obtained from the rated historical operation data of the energy supply devices in the energy supply system of the steel plant to be evaluated and the uncertainty parameter reflecting the uncertainty of the steam and power loads of the energy supply system. In this process, not only the uncertainty in the actual operation of the energy supply system is considered, but also since each plant area provides the aggregated flexible domains of the same type of energy supply devices instead of the specific parameters of individual energy supply devices, the parameters of each energy supply device within each plant area can be hidden. The present invention considers both privacy protection and load uncertainty in the process of evaluating the flexibility of the steel plant energy supply system, and can achieve a safe and accurate evaluation of the flexibility of the steel plant energy supply system. Brief Description of the Drawings

[0032] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0033] Figure 1 is a schematic flow chart of a method for evaluating the flexibility of an energy supply system in a steel plant considering privacy protection and load uncertainty provided by the present invention Figure 1 .

[0034] Figure 2 is a schematic flow chart of a method for evaluating the flexibility of an energy supply system in a steel plant considering privacy protection and load uncertainty provided by the present invention Figure 2 .

[0035] Figure 3 is a schematic structural diagram of a device for evaluating the flexibility of an energy supply system in a steel plant considering privacy protection and load uncertainty provided by the present invention.

[0036] Figure 4 is a schematic structural diagram of an electronic device provided by the present invention. Detailed Embodiments

[0037] To make the objectives, technical solutions, and advantages of the present invention clearer, the following will clearly and completely describe the technical solutions in the present invention with reference to the accompanying drawings in the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art without creative efforts based on the embodiments in the present invention fall within the scope of protection of the present invention.

[0038] The following will be combined with Figure 1-2 to describe a method for evaluating the flexibility of an energy supply system in a steel plant considering privacy protection and load uncertainty provided by the present invention. As Figure 1 shown, the method for evaluating the flexibility of an energy supply system in a steel plant considering privacy protection and load uncertainty provided by the present invention includes the following steps:

[0039] S110. Construct a description model of the energy supply system based on the equipment parameters of the energy supply system of the steel plant to be evaluated. The description model includes a steam network description sub-model in the energy supply system, a power balance constraint description sub-model of the power subsystem, a steam enthalpy value description sub-model, and an operation description sub-model of the energy supply equipment;

[0040] S120. Obtain the aggregated flexible domain of the energy supply equipment provided by each plant area of the steel plant to be evaluated. Based on the aggregated flexible domain and the description model, construct the first coupling relationship between the fuel subsystem and the steam subsystem in the energy supply system and the second coupling relationship between the steam subsystem and the power subsystem in the energy supply system. The aggregated flexible domain of the energy supply equipment is obtained by aggregating the flexible domains of the same type of energy supply equipment;

[0041] S130. Construct constraint conditions based on the first coupling relationship and the second coupling relationship, solve the flexibility evaluation objective function based on the constraint conditions, and obtain the flexibility evaluation result of the energy supply system. The flexibility evaluation result reflects the regulation ability of the energy supply system. The flexibility evaluation objective function is constructed based on the operation baseline data of the energy supply equipment. The operation baseline data of the energy supply equipment is obtained based on the historical operation data of the energy supply equipment. The uncertainties of the steam and power loads of the steel plant to be evaluated are the uncertainty parameters in the flexibility evaluation objective function.

[0042] The energy supply system structure of steel plants has certain commonalities. Generally, it consists of a gas holder for balancing the output and consumption of by-product gas in steel production, a boiler for producing high-temperature and high-pressure steam, a steam turbine for driving the generator rotor to rotate, and the configured relevant bypass valves and steam pipelines, and a microgrid within the steel plant. That is, the energy supply equipment in the energy supply system includes a gas holder, a boiler, a steam turbine, and bypass valves. When constructing a description model for the energy supply system, focus on analyzing the components of the energy supply system, the system operation principle, and the system operation boundary. Specifically, the description model of the energy supply system includes:

[0043] 1. Gas holder description sub-model

[0044] To balance the output of by-product gas in steel production and the gas consumption in subsequent processes, steel plants generally are equipped with gas holders to buffer and store by-product gas. The gas holder storage model is shown in Equation (1).

[0045]

[0046] Among them, — Type of by-product gas;

[0047] — By-product gas The corresponding gas holder's storage volume at time, km 3 ;

[0048] — The production volume of by-product gas at time, km 3 ;

[0049] — The amount of gas supplied to the energy supply link at a certain moment, km 3 ;

[0050] — The amount of gas supplied to the industrial production link at a certain moment, km 3 .

[0051] 2. Boiler description sub-model

[0052] The boiler heats saturated water by burning gas to make it dry saturated steam. The energy balance equation in the boiler is shown in Equations (2) and (3).

[0053]

[0054] Among them, —The gas energy consumed by the th boiler at the moment, kJ;

[0055] —The steam flow rate produced by the th boiler at the moment, t / h;

[0056] —The change in enthalpy value when steam flows through the th boiler, kJ / kg;

[0057] —The energy utilization efficiency of the th boiler, %;

[0058] —The calorific value of gas , kJ / kg;

[0059] —The number of types of gas;

[0060] —The number of boilers in the steam network.

[0061] 3. Steam enthalpy value description sub-model

[0062] In the energy supply system of the steel plant, the steam network can be divided into multiple layers. Each layer of the steam network corresponds to a pressure level. The energy in the steam networks of different pressure levels can be calculated by the product of enthalpy value and mass. The enthalpy value of steam can be expressed by Equations (4) and (5).

[0063]

[0064] Among them, —The enthalpy value of unsaturated steam, kJ / kg;

[0065] — Enthalpy value of saturated steam, kJ / kg;

[0066] — Pressure of unsaturated steam, bar;

[0067] — Pressure of saturated steam, bar;

[0068] — Temperature of unsaturated steam, °C;

[0069] and are fitting functions, which can be obtained by fitting the actual steam enthalpy value, temperature, and pressure data.

[0070] 4. Turbine descriptor sub-model

[0071] The steam turbines equipped in the steel plant can be divided into three types according to their steam flow paths: condensing turbines, back-pressure turbines, and extraction-back-pressure turbines. The condensing turbine can be installed in steam networks of various grades, and the steam becomes saturated steam after flowing out of it; the back-pressure turbine is installed between two grades of steam networks, and the steam flows in from the high-pressure steam network and flows out to the medium-pressure or low-pressure steam network; the extraction-back-pressure turbine is installed between multiple grades of steam networks, and the steam flows in from the high-pressure steam network and flows out from the medium- and low-pressure steam networks to meet the steam requirements of different temperatures and pressures.

[0072] For condensing turbines and back-pressure turbines, the steam flows through the turbine to drive its power generation, and its output can be expressed as Equation (6).

[0073]

[0074] Where, — Power generation of the turbine (condensing turbine and back-pressure turbine) at time t, MW;

[0075] — Power generation efficiency of the turbine (condensing turbine and back-pressure turbine) %,;

[0076] — Steam flow rate through the turbine (condensing turbine and back-pressure turbine) at time t, t / h;

[0077] — Steam enthalpy change when flowing through the turbine, kJ / kg.

[0078] The extraction-condensing steam turbine can be equivalent to multiple back-pressure steam turbines. Assume the extraction-condensing steam turbine has two outlets located in different-grade steam networks respectively, and its output can be expressed as Equation (7).

[0079]

[0080] Wherein, —The extraction-condensing steam turbine The power generation power at time t, MW;

[0081] And —The power generation power of the equivalent back-pressure steam turbine, MW.

[0082] 5. Bypass valve description sub-model

[0083] The bypass valve is installed between different pressure grades of the steam system, generally flowing in from the high-pressure steam network and flowing out from the low-pressure steam network. According to the mass and energy balance, the outlet steam flow rate of the bypass valve can be expressed as Equation (8).

[0084]

[0085] Wherein, —The bypass valve The outlet steam flow rate at time t, t / h;

[0086] —The bypass valve The inlet steam flow rate at time t, t / h;

[0087] —The bypass valve The outlet steam enthalpy value, kJ / kg;

[0088] —The bypass valve The inlet steam enthalpy value, kJ / kg;

[0089] —The enthalpy value of the condensed water generated during the steam flowing through the safety valve, kJ / kg.

[0090] 6. Steam network description sub-model

[0091] The steam network system includes multiple layers of steam networks with different pressures and steam equipment installed therein. The steam flow rate flowing through each layer should abide by the law of mass conservation, and the steam network balance relationship can be expressed by Equation (9).

[0092]

[0093] In the formula, — The vector of represents the steam flow rate through all boilers, t / h;

[0094] — The -dimensional vector represents the steam flow rate through all steam turbines, t / h;

[0095] — The number of condensing steam turbines;

[0096] — The number of back-pressure steam turbines (including equivalent back-pressure steam turbines);

[0097] — The -dimensional vector represents the steam flow rate through all bypass valves, t / h;

[0098] — The number of bypass valves;

[0099] — The incidence matrix of the steam equipment and the network.

[0100] Taking the boiler as an example, is dimensional matrix, and the element represents the connection relationship between the i-th layer of the steam network and the boiler j. If it is 1, the boiler j is in the i-th layer of the steam network; if it is 0, it is not. Similarly, , , , matrices can be obtained, which respectively represent the connection relationships between the inlets and outlets of the steam turbines and the inlets and outlets of the bypass valves and the steam network; is dimensional vector, which represents the steam load of each pressure level steam network.

[0101] 7. Power balance constraint of the power subsystem

[0102] The power generation of the energy supply system can be expressed by Equation (10):

[0103]

[0104] Among them, — The total power generation of the energy supply system, MW;

[0105] — dimensional vector represents the difference between the steam enthalpy value and the saturated steam enthalpy value in the steam network, kJ / kg;

[0106] — vector, and its elements represent the energy utilization efficiency of the steam turbines, %;

[0107] — Hadamard product operation, that is, the corresponding elements of the matrices are multiplied.

[0108] The internal power supply and demand of the steel plant satisfy formula (11).

[0109]

[0110] Among them, — The electricity purchase quantity at time, MW;

[0111] — The sum of the electricity consumption in the industrial production process and the power grid loss inside the steel plant, MW.

[0112] For the overall flexibility assessment of the energy supply system, it is necessary to consider the constraints of the multi - energy system and the limitations of its equipment constraints on the regulation ability. Specifically, the flexibility model of the energy supply system can be described as follows:

[0113] 1. The constraints of the gas subsystem can be expressed as formulas (12) and (13):

[0114]

[0115] Among them, — By - product gas The upper storage limit of the corresponding gas holder, km 3 ;

[0116] — By - product gas The lower storage limit of the corresponding gas holder, km 3 ;

[0117] — The upper limit of the supply quantity of by - product gas per unit time, km 3 ;

[0118] — The lower limit of the supply quantity of by - product gas per unit time, km 3 .

[0119] 2. The equipment capacity constraints of steam turbines, boilers, and bypass valves can be expressed as formulas (14) to (16).

[0120]

[0121] Among them, — The lower limit of the steam flow of the steam turbine, t / h;

[0122] — The upper limit of the steam flow of the steam turbine, t / h;

[0123] — The lower limit of the steam flow rate produced by the boiler, t / h;

[0124] — The upper limit of the steam flow rate produced by the boiler, t / h;

[0125] — The upper limit of the steam flow rate of the bypass valve, t / h.

[0126] 3. The ramp rate constraints of the steam turbine and the boiler can be expressed by Equations (17) to (20).

[0127]

[0128] Among them, — The baseline operating steam flow rate of the steam turbine before adjustment, t / h;

[0129] — The ratio of the upward ramp rate of the steam turbine per unit time to its equipment capacity;

[0130] — The ratio of the downward ramp rate of the steam turbine per unit time to its equipment capacity;

[0131] — The baseline operating steam flow rate of the boiler before adjustment, t / h;

[0132] — The ratio of the upward ramp rate of the boiler per unit time to its equipment capacity;

[0133] — The ratio of the downward ramp rate of the boiler per unit time to its equipment capacity;

[0134] — The adjustment duration.

[0135] Unless otherwise specified, for the symbols with a tilde on the top in the following text, they all represent the baseline operating parameters of the equipment and will not be explained repeatedly.

[0136] 4. The purchased electric power constraint and the purchased gas volume constraint can be expressed by Equations (21) to (22):

[0137]

[0138] In the formula, — The electric power purchased by the steel plant from the external power grid, MW;

[0139] — The upper limit of the purchased electric power of the steel plant from the external power grid, MW;

[0140] —Lower limit of the electric power purchased by the steel plant from the external power grid, MW;

[0141] —Gas volume purchased by the steel plant from the outside, km 3 ;

[0142] —Upper limit of the gas volume purchased by the steel plant from the outside, km 3 ;

[0143] —Lower limit of the gas volume purchased by the steel plant from the outside, km 3 。

[0144] For the equipment capacity and ramp - up ability parameters involved in the above - mentioned constraints, detailed data need to be provided by each plant area. However, the information among different plants in the steel plant is not completely transparent. Constructing an overall model of the energy supply system involves many technical and non - technical factors, and the actual operation is difficult. Therefore, the method provided by the present invention will construct a flexible domain to describe the flexibility of equipment in each plant area, avoiding the problem of leakage of the above - mentioned equipment data privacy.

[0145] Flexible domain of the energy supply system Under the condition of considering the equipment operation constraints, within a given regulation time period , it can be described by the superposition of the flexible domains of the equipment operation constraints , multi - energy coupling constraints of relevant pipelines / boilers / energy supply systems . Among them, the equipment flexible domain can be represented by a - dimensional polyhedron. Each point in the polyhedron represents the working state of the equipment corresponding to the full - time dimension within the optimization range of the polyhedron. Its general form is shown in Formulas (23) and (24).

[0146]

[0147] To characterize the flexible domain of the energy supply system, first, the flexible domains of the equipment that makes up the energy supply system need to be obtained. It can be modeled as a high - dimensional polyhedron, which contains all the operating states of the equipment from the self - confirmation service to the period of resuming normal operation. When describing the polyhedron, vertex - set representation and half - plane representation are often used.

[0148] When characterizing a steam turbine model or a load model with constraints, the half - plane representation is more concise and easier to handle. This method represents the polyhedron by the intersection of a set of half - spaces. Each set of half - spaces can be represented by an inequality which will generate a plane in space, and the space enclosed by multiple planes is the equipment flexible domain.

[0149] To describe the mutual influence of the equipment operating states at each moment, it is necessary to define the auxiliary matrix and , as shown in Equations (25) and (26) respectively.

[0150]

[0151] Taking coke oven gas as an example, the inequality coefficient matrix and column vector of the flexible region of the gas holder supply capacity can be expressed as Equations (27) and (28).

[0152]

[0153] In the formula, — identity matrix

[0154] — upper limit vector of the coke oven gas supply;

[0155] — lower limit vector of the coke oven gas supply;

[0156] — vector of the coke oven gas supply after deducting the industrial production consumption at each moment;

[0157] — vector of the coke oven gas volume produced by the coke oven at each moment;

[0158] — lower limit vector of the gas holder storage;

[0159] — upper limit vector of the gas holder storage.

[0160] Each element in the above vectors corresponds to a moment, so that the flexible region of the coke oven gas supply capacity of a single gas holder can be obtained, which can be expressed as Equation (29).

[0161]

[0162] Among them, — the point in the constructed high-dimensional polyhedron. If there are superscripts and subscripts in the following text, it also represents a certain point in the polyhedron, but different model attributes such as boilers, steam turbines, and gas tanks are given to this point, which will not be explained and elaborated in the following text.

[0163] It should be noted that the flexible region of the gas holder providing coke oven gas is obtained by taking coke oven gas as an example. According to the types of gas in the steel plant to be evaluated, a similar method can also be used to construct the flexible regions of gas holders providing other types of gas (such as blast furnace gas, converter gas, etc.).

[0164] For different types of coal gas, other flexible regions of the coal gas supply capacity of the gas holder can be constructed in a similar way.

[0165] In the steam network, the flexible region of the boiler can be expressed by Equations (30) and (31).

[0166]

[0167] Among them, —The upper limit of the steam production flow rate of the j-th boiler in the i-th layer of the steam network, t / h;

[0168] —The lower limit of the steam production flow rate of the j-th boiler in the i-th layer of the steam network, t / h;

[0169] —Represents the maximum upward ramp rate of the boiler

[0170] —Represents the maximum downward ramp rate of the boiler.

[0171] The flexible region of the j-th boiler in the i-th layer of the steam network can be expressed by Equation (32).

[0172]

[0173] For steam turbines, the steam flexible regions of condensing steam turbines and back-pressure steam turbines are similar to those of boilers. During their daily operation, they are mainly restricted by equipment capacity and ramp rate. The extraction-backpressure steam turbine can be represented as a combination of two back-pressure steam turbines. Therefore, only the flexible regions of the first two types of steam turbines need to be characterized. The steam flexible region of the j-th condensing steam turbine in the i-th layer of the steam network can be expressed by Equation (33).

[0174]

[0175] Among them, Represents the inequality coefficient matrix of the steam flexible region of the j-th condensing steam turbine in the i-th layer of the steam network, Represents the corresponding inequality column vector, and Can be established based on the steam turbine capacity constraints and ramp constraints provided above.

[0176] The outlet of the back-pressure steam turbine is still within the steam network. The steam flexible region of the k-th back-pressure steam turbine between the i-th and j-th layers can be expressed by Equation (34).

[0177]

[0178] Among them, The inequality coefficient matrix of the k-th backpressure steam turbine steam flexibility region located between the i-th and j-th layers represents the corresponding inequality column vector, and can be established based on the steam turbine capacity constraints and ramping constraints provided above.

[0179] The bypass valve flexibility region representation is similar to that of the backpressure steam turbine. The k-th bypass valve flexibility region located between the i-th and j-th layers can be expressed as Equation (35).

[0180]

[0181] Among them, The inequality coefficient matrix of the k-th bypass valve steam flexibility region located between the i-th and j-th layers represents the corresponding inequality column vector, and can be established based on the bypass valve capacity constraints provided above.

[0182] Based on the above work, by aggregating the flexibility regions through the Minkowski sum method, the aggregated flexibility regions of the gas holder, boiler, and steam turbine can be obtained.

[0183] Assume that the same type of equipment produced by the same manufacturer has the same efficiency. Each plant aggregates the flexibility regions of the same type of energy supply equipment within its own plant and provides the aggregated flexibility region to the evaluation equipment. This can hide the parameters of individual equipment. The same type of energy supply equipment refers to the same kind of energy supply equipment in the same layer of the steam network, such as boilers, bypass valves, steam turbines, etc. located in the same layer of the steam network. Through the steam flexibility regions with hidden equipment parameters provided by each plant, the evaluation equipment can achieve the supply-demand balance of steam in each link during operation, and thus can carry out flexibility evaluation work while protecting privacy. In the i-th layer of the steam network, the steam aggregated flexibility regions of each equipment are shown in detail in Equations (36) and (37).

[0184]

[0185] To obtain the steam turbine output flexibility region, its steam flexibility region needs to be changed to a certain extent, as shown in detail in Equations (38) to (40).

[0186]

[0187] Among them, the auxiliary parameters and respectively represent the conversion relationships between steam flow and power generation output. and can be expressed as Equations (41) and (42).

[0188]

[0189] Among them, represents the efficiency of the condensing steam turbine in the i-th layer of the steam network, represents the efficiency of the back-pressure steam turbine between the i-th layer and the j-th layer of the steam network, , respectively represent the enthalpy values of the steam in the i-th layer and the j-th layer of the steam network, represents the enthalpy value of the saturated steam discharged from the steam network.

[0190] In the flexible domain of the energy supply system, the coupling relationship between subsystems is reflected in the constraint relationship between multiple flexible domains. The fuel subsystem and the steam subsystem are coupled through boiler equipment, and their energy relationship is the first coupling relationship, which can be expressed by equations (43) to (45).

[0191]

[0192] represents the energy utilization efficiency of the boiler in the i-th layer of the steam network, represents the number of types of gas, represents the calorific value of the i-th type of gas, represents the operating state of the gas holder of the i-th type of gas, is the aggregated flexible domain representing the gas holder of the i-th type of gas.

[0193] The steam and power subsystems are coupled through turbine equipment. In the i-th stage steam network, the second coupling relationship between them can be described by equations (46) to (49).

[0194]

[0195] Among them, —The steam load of the i-th layer of the steam network, t / h.

[0196] Evaluate the flexibility of the energy supply system according to the flexible domain coupling relationship constructed above. The evaluation process needs to first determine the operation baseline, and then evaluate the regulation ability by integrating market demand. The operation baseline is obtained by detecting historical operation data.

[0197] The flexibility evaluation of the energy supply system is realized by summing the flexibility evaluation objective function. The flexibility evaluation objective function is the regulation ability within the specified service period.

[0198] The evaluation objective function of the valley filling auxiliary service can be expressed by equation (50).

[0199]

[0200] The above formula needs to satisfy the constraints of formulas (43)-(49) and the following formulas (51), (52).

[0201]

[0202] where — the baseline operating state of the device;

[0203] — the service start time;

[0204] — the service end time;

[0205] — the bid acceptance time;

[0206] — the time to resume normal operation.

[0207] The decision variables of the above optimization problem are the operating states of each device .

[0208] In the same way, the objective function of the peak shaving service can be obtained as shown in formula (53).

[0209] Due to the existence of the steam network, the uncertainty of the steam load will indirectly affect the output of the steam turbine through the coupling relationship, while the uncertainty of the power load directly affects the load curve. Considering the influence of the uncertainties of the steam and power loads and , formula (50) can be transformed into formula (54).

[0210]

[0211] According to the supply-demand balance relationship of the steam network, the steam flow rate of the condensing steam turbine can be linearly represented by the steam flow rates of the other links. Therefore, the objective function of the flexibility assessment can be further transformed into formula (55) as follows:

[0212] (55)

[0213] where the uncertainties of the steam load and the power load and are the uncertainty parameters of this optimization problem.

[0214] Solving formula (55), the optimization result of is obtained as the flexibility assessment result of the energy supply system.

[0215] It can be seen that the flexibility evaluation result of the energy supply system of the steel plant to be evaluated can reflect the regulation capacity of the energy supply system of the steel plant to be evaluated to participate in power auxiliary services. Based on the evaluation of the regulation capacity, in an embodiment of the method provided by the present invention, the regulation cost can be further evaluated. That is, after obtaining the flexibility evaluation result of the energy supply system by solving the flexibility evaluation objective function based on the constraint conditions, it includes:

[0216] Based on the operating states of the energy supply devices in the energy supply system corresponding to the flexibility evaluation result, determine the raw material consumption cost and the equipment life loss cost;

[0217] Based on the raw material consumption cost and the equipment life loss cost, determine the regulation cost corresponding to the flexibility evaluation result.

[0218] The operating cost of the energy supply system of the steel plant includes the raw material consumption cost and the equipment life loss cost. The raw material consumption cost includes the costs of purchasing gas, water, and electricity, and can be expressed as Equation (56).

[0219]

[0220] Among them, — The electricity price for purchasing electricity at time, £;

[0221] — The price of purchasing gas at time, £;

[0222] — The price of purchasing industrial water at time, £;

[0223] —The amount of electricity purchased at time, MW;

[0224] — The amount of natural gas purchased by the steel plant at time, km 3 ;

[0225] — The amount of industrial water purchased by the steel plant at time, t.

[0226] The equipment life loss cost refers to the cost caused by the shortening of the life of the steam turbine equipment during operation. The life of the steam turbine usually refers to the total working time from commissioning to the first appearance of macroscopic cracks in its rotor. Low-cycle fatigue damage caused by alternating thermal stress and high-temperature creep damage caused by high temperature and working stress are the main factors leading to the shortening of its life. The evaluation of the steam turbine life usually adopts the linear cumulative damage method, and the total cumulative life loss rate of the rotor is equal to the sum of the low-cycle fatigue damage and the high-temperature creep damage, which can be expressed by the following Equation (57).

[0227]

[0228] wherein, — the actual number of cycles of the component under condition i;

[0229] — the fatigue life corresponding to the actual number of cycles of the component under condition i;

[0230] — the operating time of the component under the stress and temperature of condition i;

[0231] — the time for creep fracture of the component under this stress and temperature;

[0232] — the total fatigue creep damage limit.

[0233] For short-term regulation, the stress and temperature inside the steam turbine will change with the change of output demand, but for the entire operation cycle of the steam turbine, the above process can be ignored. Therefore, mainly considering the influence of the number of cycles on the life, the life loss cost of the steam turbine can be expressed by Equation (58).

[0234]

[0235] wherein, — the number of cycles of small load change;

[0236] — the number of cycles of large load change;

[0237] — the number of hot start cycles;

[0238] — the fatigue life of small load change cycles, y;

[0239] — the fatigue life of large load change cycles, y;

[0240] — the fatigue life of hot start cycles, y;

[0241] represents the price of the steam turbine, £.

[0242] For a given regulation capacity , the objective function for evaluating its regulation cost can be expressed by Equation (59).

[0243] (59)

[0244] It is necessary to satisfy the constraints of (46) to (49), (51), (52) and the following formula:

[0245]

[0246] Due to the existence of uncertainties in steam and power loads, the solution results of the flexibility evaluation objective function vary based on different uncertainty budgets. As Figure 2 shown, in an embodiment of the method provided by the present invention, an operation baseline is generated according to historical load data provided by the steel plant or collected by terminal devices. At the same time, an uncertainty interval of the steam and power loads of the steel plant is generated according to the historical load data, and an uncertainty budget value range is further generated. Then, in combination with the operation baseline and the uncertainty interval, the regulation capacity under different uncertainty budgets is evaluated, and the uncertainty budget is selected in combination with the user's risk preference. Finally, the regulation costs of auxiliary services with different regulation capacities are evaluated to provide a reference for the steel plant user to select the service type and service capacity. That is to say, when solving the flexibility evaluation objective function, the flexibility evaluation results under multiple uncertainty budgets are adopted, which can provide more reference information for the steel plant user. For the flexibility evaluation results under each uncertainty budget, the corresponding regulation costs can be given to facilitate the steel plant user to make a plan selection. That is, based on the constraint conditions, the flexibility evaluation objective function is solved to obtain the flexibility evaluation results of the energy supply system, including:

[0247] Based on the historical data of the steam and power loads of the steel plant to be evaluated, determine the uncertainty confidence intervals of the steam and power loads of the steel plant to be evaluated;

[0248] Based on the uncertainty confidence intervals, determine the uncertainty budget value range, and obtain the flexibility evaluation results under different uncertainty budgets based on the operation baseline data and the uncertainty budget value range. The uncertainty budget reflects the conservatism of the flexibility evaluation results.

[0249] Specifically, modern steel plants are usually equipped with complete communication and detection systems, which can observe the relevant production parameters of the steel plant in real time. The difference between the actual value and the predicted value of the steam and power loads can be obtained through historical detection data, considering its confidence interval at a certain level and . To facilitate the conversion of the model, first, the proposed model is represented in a compact form, as shown in formula (61).

[0250] (61)

[0251] where —The coefficient column vector corresponding to the objective function (3 - 61);

[0252] , and —The coefficient matrix under the corresponding constraints;

[0253] —Inequality constraints in the flexible domain model of the energy supply system, which are given by , , , , The half-space set of

[0254] —Equality constraints in the model, including equation (43); —Uncertainty in steam load and electricity load;

[0255] —Optimization variable, its representation is shown in formula (62).

[0256]

[0257] in, is an auxiliary variable.

[0258] To facilitate further transformation of the model, consider swapping the two layers of optimization in the objective function of the above model. The above objective function is equivalent to formula (63).

[0259]

[0260] The minimization of the inner layer of the objective function is a linear problem. According to the strong duality theory, it can be converted into the min form as follows:

[0261]

[0262] in, , and —Dual variables corresponding to each constraint in the original second-stage minimization problem.

[0263] There are bilinear terms in the formula , the optimal solution of the dual problem corresponds to For uncertain set When the above objective function reaches the minimum value, the value of the uncertain variable u should be the boundary of the interval. In the energy supply system studied in this paper, the increase of steam load and electricity load uncertainty will reduce the upward regulation capacity, so the uncertainty set It is expressed as shown in formula (65).

[0264]

[0265] in, , — A binary auxiliary variable used to adjust the conservatism of optimization.

[0266] — The set of all simulation step sizes;

[0267] (including and ) — An uncertainty adjustment parameter used to control the conservatism of robust optimization, i.e., the uncertainty budget;

[0268] — Used to adjust the uncertainty of steam load;

[0269] Used to adjust the uncertainty of electrical load.

[0270] At different values, flexibility evaluation results with different risk preferences can be obtained. When , the load uncertainty considered is the smallest, and the evaluation result of the adjustable range of ancillary services is the least conservative; when , the uncertainty considered is the largest, and the evaluation result of the adjustable range of ancillary services is the same as that of traditional robust optimization, being the most conservative.

[0271] After substituting Equation (64) into (65), terms of multiplying binary variables by continuous variables will be generated. By introducing auxiliary variables and related constraints to further linearize it, it can be expressed as Equation (66).

[0272]

[0273] Among them, , and represent the upper bounds of the dual variables, and can take sufficiently large positive real numbers.

[0274] Through the above changes, the robust optimization objective function Equation (55) is transformed into the linear optimization problem shown in Equation (66), which can be directly solved by a commercial solver.

[0275] Next, the flexibility evaluation device for the energy supply system of a steel plant considering privacy protection and load uncertainty provided by the present invention will be described. The flexibility evaluation device for the energy supply system of a steel plant considering privacy protection and load uncertainty described below can be correspondingly referred to the flexibility evaluation method for the energy supply system of a steel plant considering privacy protection and load uncertainty described above. As Figure 3 shown, the flexibility evaluation device for the energy supply system of a steel plant considering privacy protection and load uncertainty provided by the present invention includes the following modules:

[0276] A description model construction module 310 is used to construct a description model of the energy supply system based on the equipment parameters of the energy supply system of the steel plant to be evaluated. The description model includes a steam network description sub-model in the energy supply system, a power balance constraint description sub-model of the power subsystem, a steam enthalpy value description sub-model, and an operation description sub-model of the energy supply equipment;

[0277] A flexible domain aggregation module 320 is used to obtain the aggregated flexible domain of the energy supply equipment provided by each plant area of the steel plant to be evaluated, and construct the first coupling relationship between the fuel subsystem and the steam subsystem in the energy supply system and the second coupling relationship between the steam subsystem and the power subsystem in the energy supply system based on the aggregated flexible domain and the description model. The aggregated flexible domain of the energy supply equipment is obtained by aggregating the flexible domains of the same type of energy supply equipment;

[0278] An optimization solution module 330 is used to construct constraint conditions based on the first coupling relationship and the second coupling relationship, solve the flexibility evaluation objective function based on the constraint conditions, and obtain the flexibility evaluation result of the energy supply system. The flexibility evaluation result reflects the regulation ability of the energy supply system. The flexibility evaluation objective function is constructed based on the operation baseline data of the energy supply equipment. The operation baseline data of the energy supply equipment is obtained based on the historical operation data of the energy supply equipment. The uncertainties of the steam and power loads of the steel plant to be evaluated are the uncertainty parameters in the flexibility evaluation objective function.

[0279] Figure 4 Illustrated is a schematic diagram of the physical structure of an electronic device, such as Figure 4As shown in the figure, the electronic device may include: a processor 410, a communications interface 420, a memory 430, and a communication bus 440. Among them, the processor 410, the communications interface 420, and the memory 430 complete communication with each other through the communication bus 440. The processor 410 may call the logical instructions in the memory 430 to execute a flexibility evaluation method for the energy supply system of a steel plant considering privacy protection and load uncertainty. The method includes: constructing a description model of the energy supply system based on the device parameters of the energy supply system of the steel plant to be evaluated. The description model includes a steam network description sub-model, a power balance constraint description sub-model of the power subsystem, a steam enthalpy value description sub-model, and an operation description sub-model of the energy supply equipment in the energy supply system; obtaining the aggregated flexible domain of the energy supply equipment provided by each plant area of the steel plant to be evaluated, and constructing a first coupling relationship between the fuel subsystem and the steam subsystem and a second coupling relationship between the steam subsystem and the power subsystem in the energy supply system based on the aggregated flexible domain and the description model. The aggregated flexible domain of the energy supply equipment is obtained by aggregating the flexible domains of the same type of energy supply equipment; constructing constraint conditions based on the first coupling relationship and the second coupling relationship, and solving the flexibility evaluation objective function based on the constraint conditions to obtain the flexibility evaluation result of the energy supply system. The flexibility evaluation result reflects the regulation ability of the energy supply system. The flexibility evaluation objective function is constructed based on the operation baseline data of the energy supply equipment. The operation baseline data of the energy supply equipment is obtained based on the historical operation data of the energy supply equipment. The uncertainties of the steam and power loads of the steel plant to be evaluated are the uncertainty parameters in the flexibility evaluation objective function.

[0280] In addition, when the logical instructions in the above-mentioned memory 430 are implemented in the form of a software energy supply unit and sold or used as an independent product, they can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present invention. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks, or optical discs that can store program codes.

[0281] On the other hand, the present invention also provides a computer program product, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the flexibility evaluation method of the energy supply system of the steel plant considering privacy protection and load uncertainty provided by the above-mentioned various methods. The method includes: constructing a description model of the energy supply system based on the equipment parameters of the energy supply system of the steel plant to be evaluated. The description model includes a steam network description sub-model in the energy supply system, a power balance constraint description sub-model of the power subsystem, a steam enthalpy value description sub-model, and an operation description sub-model of the energy supply equipment; obtaining the aggregated flexible domain of the energy supply equipment provided by each plant area of the steel plant to be evaluated, and constructing a first coupling relationship between the fuel subsystem and the steam subsystem in the energy supply system and a second coupling relationship between the steam subsystem and the power subsystem in the energy supply system based on the aggregated flexible domain and the description model. The aggregated flexible domain of the energy supply equipment is obtained by aggregating the flexible domains of the same type of energy supply equipment; constructing constraint conditions based on the first coupling relationship and the second coupling relationship, and solving the flexibility evaluation objective function based on the constraint conditions to obtain the flexibility evaluation result of the energy supply system. The flexibility evaluation result reflects the regulation ability of the energy supply system. The flexibility evaluation objective function is constructed based on the operation baseline data of the energy supply equipment. The operation baseline data of the energy supply equipment is obtained based on the historical operation data of the energy supply equipment. The uncertainty of the steam and power loads of the steel plant to be evaluated is the uncertainty parameter in the flexibility evaluation objective function.

[0282] In another aspect, the present invention also provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements a flexibility evaluation method for an energy supply system of a steel plant considering privacy protection and load uncertainty. The method includes: constructing a description model of the energy supply system based on the equipment parameters of the energy supply system of the steel plant to be evaluated. The description model includes a steam network description sub-model, a power balance constraint description sub-model of the power subsystem, a steam enthalpy value description sub-model, and an operation description sub-model of the energy supply equipment in the energy supply system; obtaining the aggregated flexible domain of the energy supply equipment provided by each plant area of the steel plant to be evaluated, and constructing a first coupling relationship between the fuel subsystem and the steam subsystem and a second coupling relationship between the steam subsystem and the power subsystem in the energy supply system based on the aggregated flexible domain and the description model. The aggregated flexible domain of the energy supply equipment is obtained by aggregating the flexible domains of the same type of energy supply equipment; constructing constraint conditions based on the first coupling relationship and the second coupling relationship, and solving a flexibility evaluation objective function based on the constraint conditions to obtain a flexibility evaluation result of the energy supply system. The flexibility evaluation result reflects the regulation ability of the energy supply system. The flexibility evaluation objective function is constructed based on the operation baseline data of the energy supply equipment, and the operation baseline data of the energy supply equipment is obtained based on the historical operation data of the energy supply equipment. The uncertainty of the steam and power loads of the steel plant to be evaluated is an uncertainty parameter in the flexibility evaluation objective function.

[0283] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art can understand and implement it without creative efforts.

[0284] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, and of course, also by hardware. Based on this understanding, the above technical solutions, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. The computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0285] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for evaluating the flexibility of a steel plant energy supply system considering privacy protection and load uncertainty, characterized in that: The method comprises: Based on the equipment parameters of the energy supply system of the steel plant to be evaluated, a description model of the energy supply system is constructed, wherein the description model includes a steam network description submodel in the energy supply system, a power balance constraint description submodel of the power subsystem, a steam enthalpy description submodel, and an operation description submodel of the energy supply equipment; Obtaining an aggregated flexible domain of energy supply equipment provided by each plant area of ​​the steel plant to be evaluated, and constructing a first coupling relationship between a fuel subsystem and a steam subsystem in the energy supply system and a second coupling relationship between a steam subsystem and a power subsystem in the energy supply system based on the aggregated flexible domain and the description model, wherein the aggregated flexible domain of the energy supply equipment is obtained by aggregating flexible domains of the energy supply equipment of the same type; Based on the first coupling relationship and the second coupling relationship, constraint conditions are constructed, and based on the constraint conditions, a flexibility evaluation objective function is solved to obtain a flexibility evaluation result of the energy supply system, wherein the flexibility evaluation result reflects the regulation capability of the energy supply system, and the flexibility evaluation objective function is constructed based on the operating baseline data of the energy supply equipment, and the operating baseline data of the energy supply equipment is obtained based on the historical operating data of the energy supply equipment, and the uncertainty of the steam and power loads of the steel plant to be evaluated is an uncertainty parameter in the flexibility evaluation objective function; The first coupling relationship is: The second coupling relationship is: Among them, n tier Indicates the number of layers of the steam network, It represents the change in enthalpy of steam in the i-th layer steam network when it flows through the boiler. is the operating status of each boiler in the i-th layer steam network, represents the aggregated flexible domain of all boilers in the i-th layer steam network, represents the operating status of each condensing steam turbine at the i-th layer, represents the energy utilization efficiency of the boiler in the i-th layer steam network, n gas Indicates the number of gas types, q i represents the calorific value of the i-th gas, represents the operating status of the gas tank of the i-th gas, represents the aggregated flexible domain of the gas tank of the i-th gas, represents the aggregated flexible domain of the condensing steam turbine in the i-th steam network, represents the operating status of each back-pressure steam turbine between the i-th and j-th steam networks, represents the aggregated flexible domain of the back-pressure turbines between the i-th and j-th steam networks, Indicates the operating status of each bypass valve between the i-th and j-th steam networks, represents the aggregated flexible domain of the bypass valve between the i-th and j-th steam networks, represents the steam load of the i-th steam network; The flexibility evaluation objective function is: in, The solution result is the flexibility evaluation result, P up (t) represents the controllable capacity of the energy supply system at time t, x(t), is the variable of the flexibility evaluation objective function, x(t) is the operating status of each of the energy supply devices at time t, represents the uncertainty in steam load, represents the uncertainty of the power load, It is an auxiliary parameter that represents the conversion relationship between steam flow and power generation output. represents the efficiency of the condensing steam turbine in the i-th steam network, represents the efficiency of the back-pressure turbine between the i-th and j-th steam networks, H i , H j denote the enthalpy of steam in the i-th and j-th layers of the steam network, respectively, H out represents the enthalpy of saturated steam leaving the steam network, represents the operating baseline data of the steam turbine in the i-th steam network, represents the operating baseline data of the back-pressure steam turbine between the i-th and j-th steam networks, Represents the uncertainty of the steam load of the i-th steam network.

2. The method for evaluating the flexibility of a steel plant energy supply system considering privacy protection and load uncertainty according to claim 1 is characterized in that: The energy supply equipment includes a gas tank, a boiler, a steam turbine and a bypass valve, and the steam turbine includes a back-pressure steam turbine and a condensing steam turbine.

3. The method for evaluating the flexibility of a steel plant energy supply system considering privacy protection and load uncertainty according to claim 1 is characterized in that: The step of solving the flexibility evaluation objective function based on the constraint conditions to obtain the flexibility evaluation result of the energy supply system includes: Determine the uncertainty confidence interval of the steam and power load of the steel plant to be evaluated based on the historical data of the steam and power load of the steel plant to be evaluated; The uncertainty budget value range is determined based on the uncertainty confidence interval, and the flexibility assessment results under different uncertainty budgets are obtained based on the operating baseline data and the uncertainty budget value range. The uncertainty budget reflects the degree of conservatism of the flexibility assessment results.

4. The method for evaluating the flexibility of a steel plant energy supply system considering privacy protection and load uncertainty according to claim 1 is characterized in that: After solving the flexibility evaluation objective function based on the constraint conditions to obtain the flexibility evaluation result of the energy supply system, the method includes: Determine the raw material consumption cost and the equipment life loss cost based on the operating status of each of the energy supply devices in the energy supply system corresponding to the flexibility evaluation result; The control cost corresponding to the flexibility evaluation result is determined based on the raw material consumption cost and the equipment life loss cost.

5. A steel plant energy supply system flexibility assessment device considering privacy protection and load uncertainty, characterized in that: The device comprises: A description model building module, used to build a description model of the energy supply system of the steel plant to be evaluated based on the equipment parameters of the energy supply system, the description model includes a steam network description submodel in the energy supply system, a power balance constraint description submodel of the power subsystem, a steam enthalpy description submodel, and an operation description submodel of the energy supply equipment; a flexible domain aggregation module, used to obtain the aggregated flexible domain of the energy supply equipment provided by each plant area of ​​the steel plant to be evaluated, and to construct a first coupling relationship between the fuel subsystem and the steam subsystem in the energy supply system and a second coupling relationship between the steam subsystem and the power subsystem in the energy supply system based on the aggregated flexible domain and the description model, wherein the aggregated flexible domain of the energy supply equipment is obtained by aggregating the flexible domains of the energy supply equipment of the same type; an optimization solution module, used for constructing constraint conditions based on the first coupling relationship and the second coupling relationship, solving the flexibility evaluation objective function based on the constraint conditions, and obtaining a flexibility evaluation result of the energy supply system, wherein the flexibility evaluation result reflects the regulation capability of the energy supply system, the flexibility evaluation objective function is constructed based on the operating baseline data of the energy supply equipment, and the operating baseline data of the energy supply equipment is obtained based on the historical operating data of the energy supply equipment, and the uncertainty of the steam and power loads of the steel plant to be evaluated is the uncertainty parameter in the flexibility evaluation objective function; The first coupling relationship is: The second coupling relationship is: Among them, n tier Indicates the number of layers of the steam network, It represents the change in enthalpy of steam in the i-th layer steam network when it flows through the boiler. is the operating status of each boiler in the i-th layer steam network, represents the aggregated flexible domain of all boilers in the i-th layer steam network, represents the operating status of each condensing steam turbine at the i-th layer, represents the energy utilization efficiency of the boiler in the i-th layer steam network, n gas Indicates the number of gas types, q i represents the calorific value of the i-th gas, represents the operating status of the gas tank of the i-th gas, represents the aggregated flexible domain of the gas tank of the i-th gas, represents the aggregated flexible domain of the condensing steam turbine in the i-th steam network, represents the operating status of each back-pressure steam turbine between the i-th and j-th steam networks, represents the aggregated flexible domain of the back-pressure turbines between the i-th and j-th steam networks, Indicates the operating status of each bypass valve between the i-th and j-th steam networks, represents the aggregated flexible domain of the bypass valve between the i-th and j-th steam networks, represents the steam load of the i-th steam network; The flexibility evaluation objective function is: in, The solution result is the flexibility evaluation result, P up (t) represents the controllable capacity of the energy supply system at time t, x(t), is the variable of the flexibility evaluation objective function, x(t) is the operating status of each of the energy supply devices at time t, represents the uncertainty in steam load, represents the uncertainty of the power load, It is an auxiliary parameter that represents the conversion relationship between steam flow and power generation output. represents the efficiency of the condensing steam turbine in the i-th steam network, represents the efficiency of the back-pressure turbine between the i-th and j-th steam networks, H i , H j denote the enthalpy of steam in the i-th and j-th layers of the steam network, H out represents the enthalpy of saturated steam leaving the steam network, represents the operating baseline data of the steam turbine in the i-th steam network, represents the operating baseline data of the back-pressure steam turbine between the i-th and j-th steam networks, Represents the uncertainty of the steam load of the i-th steam network.

6. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method for evaluating the flexibility of the energy supply system of a steel plant taking into account privacy protection and load uncertainty as described in any one of claims 1 to 4 is implemented.

7. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for evaluating the flexibility of a steel plant energy supply system taking into account privacy protection and load uncertainty as described in any one of claims 1 to 4 is implemented.

8. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the method for evaluating the flexibility of a steel plant energy supply system taking into account privacy protection and load uncertainty as described in any one of claims 1 to 4 is implemented.

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