Iron and steel plant energy supply system flexibility evaluation method considering privacy protection and load uncertainty

Abstract

The invention provides an iron and steel plant energy supply system flexibility evaluation method considering privacy protection and load uncertainty. The method comprises the following steps: constructing a description model of an energy supply system based on equipment parameters of the energy supply system of an iron and steel plant to be evaluated; acquiring an aggregation flexible domain of energy supply equipment provided by each factory, 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 the steam subsystem and an electric power subsystem in the energy supply system based on the aggregation flexible domain and the description model; and constructing a constraint condition based on the first coupling relationship and the second coupling relationship, solving the flexibility evaluation objective function based on the constraint condition, and obtaining a flexibility evaluation result of the energy supply system, the flexibility evaluation result reflecting the regulation and control capability of the energy supply system. The uncertainty of the steam and power load of the to-be-evaluated iron and steel plant is an uncertainty parameter in the flexibility evaluation objective function. According to the method, privacy protection and load uncertainty are considered at the same time, and safe and accurate flexibility evaluation can be realized.

Description

Technical Field

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

[0002] As a high-energy-consuming industry, steel mills consume a lot of electricity during their operation, so they are often constrained by the power grid, the power supply capacity of self-provided power plants, and other factors. When the external power grid or its self-provided power plant supplies power to them, there will often be a certain degree of fluctuation. For example, when the power grid is limited, some power loads in the factory should be operated at reduced power. In order to ensure that the power loads in the steel production process are deeply involved in the peak load regulation of the power grid and to maximize the overall efficiency of the production system, it is necessary to model the production process of the steel mill and flexibly regulate it.

[0003] Accurately assessing one's own flexibility is the premise and basis for steel plants to correctly choose and participate in power auxiliary services. At present, there has been work to evaluate the flexibility of steel plant energy supply systems. However, steel plants have long production processes and energy supply systems cover multiple coupled networks such as electricity, steam, and gas. Their control capabilities are subject to multiple constraints, and it is difficult to simply evaluate their flexibility by superimposing equipment capabilities. At the same time, differences in material properties and uncertainty in transmission delays will lead to uncertainty in production electricity and steam loads, affecting the accuracy of the energy supply system flexibility assessment. In addition, the information of each plant area of ​​the steel plant is not completely transparent, and the flexibility assessment of the energy supply system requires the cooperation of multiple plant areas. The sharing of information may lead to the leakage of equipment operating parameters, thereby damaging the interests of each plant area. The flexibility assessment of the energy supply system of steel plants in the existing technology does not take into account uncertainty and privacy protection issues, resulting in inaccurate flexibility assessment results of the energy supply system of steel plants and the risk of information leakage. Summary of the invention

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

[0005] The present invention provides a method for evaluating the flexibility of a steel plant energy supply system considering privacy protection and load uncertainty, the method comprising: 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, constraints are constructed, and the flexibility evaluation objective function is solved based on the constraints to obtain a flexibility evaluation result of the energy supply system. 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. 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.

[0006] According to a method for evaluating the flexibility of a steel plant energy supply system that takes into account privacy protection and load uncertainty, the present invention provides an energy supply equipment that 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.

[0007] According to a method for evaluating the flexibility of a steel plant energy supply system considering privacy protection and load uncertainty provided by the present invention, the first coupling relationship is: ; The second coupling relationship is: ; in, 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, Indicates the number of gas types, 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.

[0008] According to a method for evaluating the flexibility of a steel plant energy supply system considering privacy protection and load uncertainty provided by the present invention, the flexibility evaluation objective function is: ; in, The solution result is the flexibility evaluation result. represents the controllable capacity of the energy supply system at time t, , , the variables of the objective function evaluated for said flexibility, is the operating status of each energy supply device 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, , denote the enthalpy of steam in the i-th and j-th layers of the steam network, respectively. 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.

[0009] According to a method for evaluating the flexibility of a steel plant energy supply system considering privacy protection and load uncertainty provided by the present invention, 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.

[0010] According to a method for evaluating the flexibility of a steel plant energy supply system considering privacy protection and load uncertainty provided by the present invention, after solving the flexibility evaluation objective function based on the constraint conditions and obtaining the flexibility evaluation result of the energy supply system, the method comprises: 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.

[0011] The present invention also provides a device for evaluating the flexibility of a steel plant energy supply system taking into account privacy protection and load uncertainty, the device comprising: 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 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, 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. 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.

[0012] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, it implements a flexibility assessment method for a steel plant energy supply system that considers privacy protection and load uncertainty as described in any one of the above-mentioned methods.

[0013] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon. 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 the above methods.

[0014] The present invention also provides a computer program product, comprising a computer program, which, when executed by a processor, implements the flexibility assessment method for a steel plant energy supply system that considers privacy protection and load uncertainty as described in any one of the above methods.

[0015] The flexibility evaluation method of the energy supply system of a steel plant provided by the present invention taking into account privacy protection and load uncertainty is provided by first constructing a description model describing the energy supply system, and obtaining the aggregated flexibility domain of each energy supply equipment provided by each plant area, constructing 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 flexibility, constructing constraints based on the first coupling relationship and the second coupling relationship, solving the flexibility evaluation objective function based on the constraints and the description model, and obtaining the flexibility evaluation result of the energy supply system, wherein the flexibility evaluation objective function includes the operation baseline data obtained by the rated historical operation data of the energy supply equipment in the energy supply system of the steel plant to be evaluated and the uncertainty parameters 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 because each plant area provides the aggregated flexibility domain of the same type of energy supply equipment instead of the specific parameters of a single energy supply equipment, so that the parameters of each energy supply equipment in each plant area can be hidden. The present invention considers privacy protection and load uncertainty at the same time in the process of evaluating the flexibility of the energy supply system of the steel plant, and can achieve safe and accurate flexibility evaluation of the energy supply system of the steel plant. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 The schematic diagram of the process of the steel plant energy supply system flexibility evaluation method considering privacy protection and load uncertainty provided by the present invention is as follows Figure 1 .

[0018] Figure 2 The schematic diagram of the process of the steel plant energy supply system flexibility evaluation method considering privacy protection and load uncertainty provided by the present invention is as follows Figure 2 .

[0019] Figure 3 It is a structural schematic diagram of a steel plant energy supply system flexibility assessment device taking privacy protection and load uncertainty into consideration, provided by the present invention.

[0020] Figure 4 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] Combine the following Figure 1-2 The present invention describes a method for evaluating the flexibility of a steel plant energy supply system considering privacy protection and load uncertainty. Figure 1 As shown, the steel plant energy supply system flexibility assessment method considering privacy protection and load uncertainty provided by the present invention includes the following steps: S110, 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, 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; S120, obtaining the 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. The aggregated flexible domain of the energy supply equipment is obtained by aggregating the flexible domains of energy supply equipment of the same type; S130. Construct constraints based on the first coupling relationship and the second coupling relationship, solve the flexibility evaluation objective function based on the constraints, and obtain the flexibility evaluation result of the energy supply system. 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. The operating baseline data of the energy supply equipment is obtained based on the historical operating 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.

[0023] The energy supply system structure of steel plants has certain commonalities. It is generally composed of gas tanks that balance the output and consumption of by-product gas in steel production, boilers that produce high-temperature and high-pressure steam, steam turbines that drive the generator rotor to rotate, and the associated bypass valves and steam pipelines, and microgrids within the steel plant. In other words, the energy supply equipment in the energy supply system includes gas tanks, boilers, steam turbines, and bypass valves. When constructing a descriptive model for the energy supply system, the focus is on analyzing the components of the energy supply system, the system operation principle, and the system operation boundary. Specifically, the descriptive model of the energy supply system includes: 1. Gas tank description sub-model

[0024] In order to balance the output of by-product gas from steel production and the gas consumption in subsequent links, steel plants are generally equipped with gas tanks to buffer and store by-product gas. The gas tank storage model is detailed in formula (1).

[0025]

[0026] in, —Type of by-product gas; —Byproduct gas The corresponding gas tank is Reserve at the moment, km 3 ; — By-product gas Production volume, km 3 ; — The amount of gas provided to the energy supply link at any time, km 3 ; — The amount of gas provided to industrial production at any time, km 3 .

[0027] 2. Boiler Descriptor Model

[0028] The boiler heats saturated water to become dry saturated steam by burning coal gas. The energy balance equation in the boiler is shown in equations (2) and (3).

[0029]

[0030] in, —No. Boilers in Gas energy consumed at any moment, kJ; —No. Boilers in Steam flow rate produced at any moment, t / h; — Steam flows through Enthalpy change per boiler, kJ / kg; —No. Energy efficiency of each boiler, %; -gas Calorific value, kJ / kg; - Number of types of gas; —Number of boilers in the steam network.

[0031] 3. Steam enthalpy descriptor model

[0032] In the energy supply system of a steel plant, the steam network can be divided into multiple layers, each of which corresponds to a pressure level. The energy in the steam networks of different pressure levels can be calculated by multiplying the enthalpy value by the mass. The enthalpy value of steam can be expressed by equations (4) and (5).

[0033]

[0034] in, —Unsaturated steam enthalpy, kJ / kg; —Enthalpy of saturated steam, kJ / kg; —Unsaturated steam pressure, bar; —pressure of saturated steam, bar; —Temperature of unsaturated steam, °C; and As a fitting function, it can be obtained by fitting the actual steam enthalpy, temperature and pressure data.

[0035] 4. Steam Turbine Description Submodel

[0036] Steam turbines installed in steel plants can be divided into three types according to their steam flow paths: condensing steam turbines, back-pressure steam turbines, and back-pressure steam turbines. Condensing steam turbines can be installed in steam networks of various levels, and steam becomes saturated steam after flowing out of them; back-pressure steam turbines are installed between two levels of steam networks, and steam flows in from the high-pressure steam network and flows out to the medium-pressure or low-pressure steam network; back-pressure steam turbines are installed between multiple levels of steam networks, and steam flows in from the high-pressure steam network and flows out from the medium- and low-pressure steam networks, meeting steam requirements at different temperatures and pressures.

[0037] For condensing steam turbines and back-pressure steam turbines, steam flows through the turbine to drive it to generate electricity, and its output can be expressed as formula (6).

[0038]

[0039] in, —Steam turbines (condensing steam turbines and back pressure steam turbines) Power generation at time t, MW; —Steam turbines (condensing steam turbines and back pressure steam turbines) Power generation efficiency, % —Flow through the steam turbine (condensing steam turbine and back pressure steam turbine) at time t Steam flow rate, t / h; —Steam flows through the turbine Change in steam enthalpy at time, kJ / kg.

[0040] The back-pressure steam turbine can be equivalent to multiple back-pressure steam turbines. Assuming that the back-pressure steam turbine There are two outlets located in different levels of steam networks, and their output can be expressed as formula (7).

[0041]

[0042] in, —Back-type steam turbine Power generation at time t, MW; and —Equivalent back-pressure steam turbine power generation, MW.

[0043] 5. Bypass valve description sub-model

[0044] The bypass valve is installed between different pressure levels of the steam system. It generally flows in from the high-pressure steam network and flows out from the low-pressure steam network. According to the mass energy balance, the steam flow rate at the bypass valve outlet can be expressed as formula (8).

[0045]

[0046] in, —Bypass valve The outlet steam flow rate at time t, t / h; —Bypass valve Inlet steam flow rate at time t, t / h; —Bypass valve The outlet steam enthalpy, kJ / kg; —Bypass valve Inlet steam enthalpy, kJ / kg; —Enthalpy of condensed water generated during steam circulation through the safety valve, kJ / kg.

[0047] 6. Steam Network Descriptor Model

[0048] The steam network system consists of multiple layers of steam networks with different pressures and steam equipment installed therein. The steam flow rate flowing through each layer should comply with the law of conservation of mass. The steam network balance relationship can be expressed by equation (9).

[0049]

[0050] In the formula, — The vector represents the steam flow rate through all boilers, t / h; — dimensional vector, representing the steam flow through all steam turbines, t / h; - number of condensing steam turbines; —The number of back-pressure steam turbines (including equivalent back-pressure steam turbines); — dimensional vector, representing the steam flow through all bypass valves, t / h; —Number of bypass valves; —The correlation matrix between steam equipment and network.

[0051] Take boiler as an example. for dimensional matrix, where the elements Indicates the connection relationship between the i-th layer of the steam network and boiler j. If it is 1, boiler j is in the i-th layer of the steam network, and if it is 0, it is not. Similarly, we can get , , , The matrices represent the connectivity between the turbine inlet and outlet, the bypass valve inlet and outlet, and the steam network; for dimensional vector, which represents the steam load of the steam network at each pressure level.

[0052] 7. Power balance constraints of power subsystem

[0053] The power generation of the energy supply system can be expressed as formula (10):

[0054] in, —Total power generation of the energy supply system, MW; — dimensional vector, representing the difference between the steam enthalpy in the steam network and the saturated steam enthalpy, kJ / kg; — A vector whose elements represent the energy utilization efficiency of the steam turbine, %; —Hadamard product operation, that is, multiplying the corresponding bit elements of the matrix.

[0055] The electricity supply and demand within the steel plant satisfies equation (11).

[0056]

[0057] in, — The amount of electricity purchased at the moment, MW; —The sum of electricity consumption in the industrial production process and the internal power grid losses of the steel plant, MW.

[0058] The overall flexibility assessment of the energy supply system needs to consider the restrictions on the regulation capacity imposed by the constraints of multiple energy systems and their equipment. Specifically, the flexibility model of the energy supply system can be described as follows: 1. The gas subsystem constraints can be expressed as equations (12) and (13):

[0059] in, —Byproduct gas The corresponding storage limit of the gas tank, km3 ; —Byproduct gas The corresponding storage limit of the gas tank, km 3 ; —Byproduct gas per unit time Supply limit, km 3 ; —Byproduct gas per unit time The lower limit of supply, km 3 .

[0060] 2. The capacity constraints of steam turbine, boiler and bypass valve equipment can be expressed as equations (14) to (16).

[0061]

[0062] in, —Lower limit of steam flow rate of steam turbine, t / h; —Upper limit of steam flow of steam turbine, t / h; —Lower limit of boiler steam flow rate, t / h; —The upper limit of the steam flow rate produced by the boiler, t / h; —Upper limit of bypass valve steam flow, t / h.

[0063] 3. The ramp constraints of steam turbines and boilers can be expressed as equations (17) to (20).

[0064]

[0065] in, —Baseline operating steam flow of the turbine before adjustment, t / h; —Ratio of the turbine's upward climbing ability per unit time to its equipment capacity; —Ratio of the downward climbing ability of the steam turbine per unit time to its equipment capacity; —Baseline operating steam flow of the boiler before adjustment, t / h; —Ratio of the boiler's upward ramping capacity per unit time to its equipment capacity; —Ratio of the boiler's downward ramping capacity per unit time to its equipment capacity; —Adjust duration.

[0066] Unless otherwise specified, the symbols with wavy lines above them in the following text represent the baseline operating parameters of the equipment and will not be explained further.

[0067] 4. The power purchase constraint and gas purchase quantity constraint can be expressed as equations (21) to (22):

[0068] In the formula, —The amount of electricity purchased by the steel plant from the external power grid, MW; —The upper limit of the power that the steel plant can purchase from the external power grid, MW; —The lower limit of the power that the steel plant can purchase from the external power grid, MW; —The amount of coal gas purchased by the steel plant from outside, km 3 ; —The upper limit of the amount of coal gas purchased by the steel plant from the outside, km 3 ; —The lower limit of the amount of coal gas purchased by the steel plant from the outside, km 3 .

[0069] The equipment capacity and ramping capability parameters involved in the above constraints require detailed data from each plant area. However, the information between the various plants in the steel plant is not completely transparent. Building an overall model of the energy supply system involves many technical and non-technical factors, and the actual operation is difficult. To this end, the method provided by the present invention will construct a flexible domain to characterize the flexibility of the equipment in each plant area to avoid the above equipment data privacy leakage problem.

[0070] Flexible domain of energy supply system Under the condition of considering the equipment operation constraints, Within, constrained by equipment operation , multi-energy coupling constraints of related pipelines / boilers / energy supply systems The flexible domain of the device can be described by superposition of the flexible domain of dimensional polyhedron, each point in the polyhedron Represents the working state of the equipment corresponding to the polyhedron in the full time dimension within the optimization range. Its general form is shown in equations (23) and (24).

[0071]

[0072] In order to characterize the flexible domain of the energy supply system, it is first necessary to obtain the flexible domain of the equipment that constitutes the energy supply system, which can be modeled as a high-dimensional polyhedron. The polyhedron contains all the operating states of the equipment from the time when the service is confirmed to the time when the normal operation is restored. When describing the polyhedron, vertex set representation and half-plane representation are often used.

[0073] When characterizing turbine models or load models with constraints, the half-plane representation is more concise and easier to handle. This method represents the polyhedron by intersecting half-space sets, each of which can be represented by an inequality To express it, this inequality will generate a plane in the space, and the space enclosed by multiple planes is the device flexibility domain.

[0074] In order to describe the mutual influence of the equipment operating status at each moment, it is necessary to define the auxiliary matrix and , see formula (25), (26) respectively.

[0075]

[0076] Taking coke oven gas as an example, the inequality coefficient matrix and column vector of the flexible domain of gas tank supply capacity can be expressed as Equations (27) and (28).

[0077]

[0078] In the formula, —Identity Matrix

[0079] —The upper limit vector of coke oven gas supply; —Lower limit vector of coke oven gas supply; —The coke oven gas supply vector after deducting the industrial production consumption at each moment; —The vector of the amount of coke oven gas produced by the coke oven at each moment; —The lower limit vector of the gas tank’s storage capacity; —The upper limit vector of the gas tank’s storage capacity.

[0080] Each element in the above vector corresponds to a moment, so the flexible domain of coke oven gas supply capacity of a single gas holder can be obtained, which can be expressed as formula (29).

[0081]

[0082] in, —Points in the constructed high-dimensional polyhedron. In the following text, if there are superscripts or subscripts It is also represented as a point in a polyhedron, but it is given different model attributes such as boiler, turbine, gas tank, etc., which will not be explained in detail in the following text.

[0083] It is worth mentioning that The flexible domain of a gas holder that provides coke oven gas is obtained by taking coke oven gas as an example. According to the type of gas in the steel plant to be evaluated, a similar method can also be used to construct a flexible domain of a gas holder that provides other types of gas (such as blast furnace gas, converter gas, etc.).

[0084] For different types of gas, other gas supply capacity flexible domains of the gasholder can be constructed in a similar way.

[0085] In the steam network, the flexible domain of the boiler can be expressed as Equations (30) and (31).

[0086]

[0087] in, —The upper limit of the steam flow rate produced by the jth boiler in the i-th steam network, t / h; —The lower limit of the steam flow rate produced by the jth boiler in the i-th layer steam network, t / h; —Indicates the maximum upward climbing capacity of the boiler

[0088] —Indicates the maximum downward climbing capacity of the boiler.

[0089] The flexible domain of the jth boiler in the i-th layer of the steam network can be expressed as formula (32).

[0090]

[0091] For steam turbines, the steam flexibility domain of condensing steam turbines and back-pressure steam turbines is similar to that of boilers. In daily operation, they are mainly constrained by equipment capacity and climbing capability. The back-pressure steam turbine can be expressed as a combination of two back-pressure steam turbines. Therefore, it is only necessary to characterize the flexibility domain of the first two types of steam turbines. The steam flexibility domain of the jth condensing steam turbine in the i-th steam network can be expressed as formula (33).

[0092]

[0093] in, 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 It can be established based on the turbine capacity constraint and ramp constraint provided in the previous text.

[0094] The back-pressure steam turbine outlet is still located in the steam network, and the kth back-pressure steam turbine steam flexible domain located between the i-th and j-th layers can be expressed as formula (34).

[0095]

[0096] in, represents the inequality coefficient matrix of the kth back-pressure steam turbine steam flexibility region between the i-th and j-th layers, represents the corresponding inequality column vector, and It can be established based on the turbine capacity constraint and ramp constraint provided in the previous text.

[0097] The representation of the bypass valve flexibility domain is similar to that of the back-pressure steam turbine. The kth bypass valve flexibility domain located between the i-th and j-th layers can be expressed as formula (35).

[0098]

[0099] in, represents the inequality coefficient matrix of the kth bypass valve steam flexible domain located between the i-th and j-th layers, represents the corresponding inequality column vector, and It can be established based on the bypass valve capacity constraint provided above.

[0100] Based on the above work, the flexible domains are aggregated by the Minkowski sum method, and the aggregated flexible domains of the gasholder, boiler and turbine can be obtained.

[0101] Assuming that the same type of equipment produced by the same manufacturer has the same efficiency, each plant aggregates the flexible domains of the same type of energy supply equipment in the plant and provides the aggregated flexible domain to the evaluation device, so that the parameters of individual equipment can be hidden. The same type of energy supply equipment refers to the same type of energy supply equipment in the same layer of steam network, such as boilers, bypass valves, steam turbines, etc. in the same layer of steam network. The evaluation device can achieve the balance of steam supply and demand in each link of operation through the steam flexible domain provided by each plant with hidden equipment parameters, and then carry out flexibility evaluation while protecting privacy. In the i-th layer steam network, the steam aggregated flexible domain of each device is shown in Equations (36) and (37).

[0102]

[0103] In order to obtain the flexible range of steam turbine output, its steam flexible range needs to be changed to a certain extent, see equations (38) to (40) for details.

[0104]

[0105] Among them, the auxiliary parameters and They respectively represent the conversion relationship between steam flow and power generation output. and It can be expressed as formula (41), (42).

[0106]

[0107] in, 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, , denote the enthalpy of steam in the i-th and j-th layers of the steam network, respectively. Indicates the enthalpy of saturated steam leaving the steam network.

[0108] In the flexible domain of the energy supply system, the coupling relationship between the subsystems is reflected as the constraint relationship between multiple flexible domains. The fuel subsystem and the steam subsystem are coupled through the boiler equipment, and their energy relationship is the first coupling relationship, which can be expressed as equations (43) to (45).

[0109]

[0110] represents the energy utilization efficiency of the boiler in the i-th layer steam network, Indicates the number of gas types, represents the calorific value of the i-th gas, represents the operating status of the gas tank of the i-th gas, is the aggregation flexible domain representing the gas cabinet of the i-th gas.

[0111] The steam and power subsystems are coupled through the steam turbine equipment. In the i-th level steam network, the second coupling relationship between the two can be described as equations (46) to (49).

[0112]

[0113] in, —Steam load of the i-th layer steam network t / h.

[0114] The flexibility of the energy supply system is evaluated based on the flexible domain coupling relationship constructed in the previous article. The evaluation process requires first determining the operating baseline, and then integrating market demand to evaluate the regulation capability. The operating baseline is obtained by testing historical operating data.

[0115] The flexibility evaluation of the energy supply system is achieved by summing up the flexibility evaluation objective function, which is the regulation capability within a specified service period.

[0116] The evaluation objective function of valley filling auxiliary service can be expressed as formula (50).

[0117]

[0118] The above formula must satisfy the constraints of formulas (43)-(49) and the following formulas (51) and (52).

[0119]

[0120] in, —Equipment baseline operating status; —Service start time; —Service end time; — Bid acceptance time; —Restore uptime.

[0121] The decision variables of the above optimization problem are the operating status of each device .

[0122] In the same way, the objective function of peak shaving service can be obtained as shown in formula (53).

[0123] Due to the existence of the steam network, the uncertainty of steam load will indirectly affect the turbine output through the coupling relationship, while the uncertainty of power load will directly affect the load curve. and , equation (50) can be transformed into equation (54).

[0124]

[0125] According to the balance between supply and demand of the steam network, the steam flow of the condensing steam turbine can be linearly represented by the steam flow of other links. Therefore, the flexibility evaluation objective function can be further transformed into formula (55) as follows: (55)

[0126] Among them, the uncertainty of steam load and power load and is the uncertainty parameter of the optimization problem.

[0127] Solving equation (55), we get The optimization results are used as the flexibility evaluation results of the energy supply system.

[0128] It can be seen that the flexibility evaluation result of the energy supply system of the steel plant to be evaluated can reflect the control capacity of the energy supply system of the steel plant to be evaluated that can participate in the power auxiliary service. On the basis of the control capacity evaluation, in one embodiment of the method provided by the present invention, the control cost can be further evaluated. That is, after solving the flexibility evaluation objective function based on the constraint conditions and obtaining the flexibility evaluation result of the energy supply system, it includes: Determine the cost of raw material consumption and the cost of equipment life loss based on the operating status of each energy supply equipment in the energy supply system corresponding to the flexibility assessment 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.

[0129] The operating cost of the energy supply system of a steel plant includes the cost of raw material consumption and the cost of equipment life loss. The cost of raw material consumption includes the cost of purchasing gas, water and electricity, which can be expressed as formula (56).

[0130]

[0131] in, — The electricity price at the time of purchase, £; — The price of gas at the moment, £; — The price of industrial water purchased at any given moment, £; —Amount of electricity purchased at any given moment, MW; — The amount of natural gas purchased by the steel plant at the moment, km 3 ; — The amount of industrial water purchased by the steel plant at time t.

[0132] Equipment life loss cost refers to the cost caused by the shortened life of steam turbine equipment during operation. The life of a steam turbine usually refers to the total working time from commissioning to the first macro cracks appearing on 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 steam turbine life usually adopts the linear cumulative damage method. The cumulative total life loss rate of the rotor is equal to the sum of low-cycle fatigue damage and high-temperature creep damage, which can be expressed by the following formula (57).

[0133]

[0134] in, —The actual number of cycles of the component under working condition i; —Fatigue life corresponding to the actual number of cycles of the component under working condition i; — Operating time of components under stress and temperature of condition i; —The time for a component to creep rupture at this stress and temperature; —Total fatigue creep damage limit.

[0135] For short-term regulation, the stress and temperature inside the turbine will change with the change of output demand, but for the entire operation cycle of the turbine, the above process can be ignored. Therefore, the impact of the number of cycles on the life is mainly considered, and the turbine life loss cost can be expressed as formula (58).

[0136]

[0137] in, —Number of small load change cycles; —Number of large load changes; —Number of hot start cycles; — fatigue life of small amplitude variable load cycle, y; — fatigue life of large-scale variable load cycles, y; —fatigue life of hot start cycle, y; represents the price of the steam turbine, £.

[0138] For a given control capacity , the objective function of its regulation cost evaluation can be expressed as formula (59).

[0139] (59)

[0140] It must satisfy the constraints (46)~(49), (51), (52) and the following equation:

[0141] Due to the uncertainty of steam and power loads, the solution of the flexibility evaluation objective function is different based on the uncertainty budget. Figure 2As shown, in one embodiment of the method provided by the present invention, an operating baseline is generated based on historical load data provided by the steel plant or collected by the terminal equipment. At the same time, uncertainty intervals of the steam and power loads of the steel plant are generated based on the historical load data, and an uncertainty budget value interval is further generated. After that, the control capacity under different uncertainty budgets is evaluated in combination with the operating baseline and the uncertainty interval, and the uncertainty budget is selected in combination with the user's risk preference. Finally, the control cost of auxiliary services with different control capacities is evaluated to provide a reference for steel plant users to select service types and service capacities. In other words, when solving the flexibility evaluation objective function, the flexibility evaluation results under a variety of uncertainty budgets are used, so that more reference information can be given to steel plant users. For each flexibility evaluation result under an uncertainty budget, the corresponding control cost can be given to facilitate the steel plant users to select solutions. That is, the flexibility evaluation objective function is solved based on the constraints to obtain the flexibility evaluation results of the energy supply system, including: Based on the historical data of steam and electricity load of the steel plant to be evaluated, determine the uncertainty confidence interval of the steam and electricity 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 conservatism of the flexibility assessment results.

[0142] Specifically, modern steel plants are usually equipped with complete communication and detection systems, which can observe the relevant production parameters of the steel plants in real time. The difference between the actual value and the predicted value of steam and power load can be obtained through historical detection data, and the confidence interval at a certain level can be considered. and To facilitate the transformation of the model, the proposed model is first expressed in a compact form, as shown in formula (61).

[0143] (61)

[0144] in, —coefficient column vector corresponding to the objective function (3-61); , and —The coefficient matrix under the corresponding constraints; —Inequality constraints in the flexible domain model of the energy supply system, which are given by , , , , The half-space set of —Equality constraints in the model, including equation (43); —Uncertainty in steam load and electricity load; —Optimization variable, its representation is shown in formula (62).

[0145]

[0146] in, is an auxiliary variable.

[0147] 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).

[0148]

[0149] 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:

[0150] in, , and —Dual variables corresponding to each constraint in the original second-stage minimization problem.

[0151] 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).

[0152]

[0153] in, , —Binary auxiliary variable used to adjust the conservativeness of the optimization.

[0154] —The set of all simulation steps; (include and ) — uncertainty adjustment parameter used to control the conservatism of robust optimization, i.e., uncertainty budget; —Uncertainty in adjusting steam load; Used to adjust for uncertainty in electrical loads.

[0155] In different Under different values, we can obtain flexibility assessment results with different risk preferences. When , the load uncertainty is the smallest, and the evaluation result of the adjustable range of ancillary services is the least conservative; when When , the uncertainty considered is the largest, and the evaluation result of the controllable range of ancillary services is the same as that of traditional robust optimization, which is the most conservative.

[0156] Substituting equation (64) into (65) will generate a term of multiplication of binary variables and continuous variables, which can be further linearized by introducing auxiliary variables and related constraints, and can be expressed as equation (66).

[0157]

[0158] in, , and represents the upper bound of the dual variable and can be a sufficiently large positive real number.

[0159] Through the above changes, the robust optimization objective function (55) is transformed into a linear optimization problem shown in (66), which can be directly solved by a commercial solver.

[0160] The following is a description of the steel plant energy supply system flexibility assessment device considering privacy protection and load uncertainty provided by the present invention. The steel plant energy supply system flexibility assessment device considering privacy protection and load uncertainty described below and the steel plant energy supply system flexibility assessment method considering privacy protection and load uncertainty described above can be referenced to each other. Figure 3 As shown, the steel plant energy supply system flexibility assessment device considering privacy protection and load uncertainty provided by the present invention includes the following modules: A description model building module 310 is used to build 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, 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; The 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 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. 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; The 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 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. 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.

[0161] Figure 4 An example of a physical structure diagram of an electronic device is shown in FIG. Figure 4 As shown, the electronic device may include: a processor 410, a communications interface 420, a memory 430 and a communication bus 440, wherein the processor 410, the communications interface 420 and the memory 430 communicate with each other via the communication bus 440. The processor 410 may call the logic instructions in the memory 430 to execute a method for evaluating the flexibility of a steel plant energy supply system that takes into account privacy protection and load uncertainty, the method comprising: 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 comprising a steam network description sub-model within the energy supply system, a power balance constraint description sub-model of the power sub-system, a steam enthalpy description sub-model, and an operation description sub-model of the energy supply equipment; obtaining an aggregated flexibility 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 sub-system and the steam sub-system in the energy supply system and a description model of the energy supply equipment based on the aggregated flexibility domain and the description model; The second coupling relationship between the steam subsystem and the power subsystem in the energy 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; based on the first coupling relationship and the second coupling relationship, constraints are constructed, and the flexibility evaluation objective function is solved based on the constraints 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 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. 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.

[0162] In addition, the logic instructions in the above-mentioned memory 430 can be implemented in the form of a software power supply unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0163] 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 steel plant energy supply system flexibility assessment method considering privacy protection and load uncertainty provided by the above-mentioned 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 including a steam network description sub-model in the energy supply system, a power balance constraint description sub-model of the power sub-system, a steam enthalpy description sub-model, and an operation description sub-model of the energy supply equipment; obtaining an aggregated flexibility domain of the energy supply equipment provided by each plant area of ​​the steel plant to be evaluated, and based on the aggregated flexibility domain, And describe the model to 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; based on the first coupling relationship and the second coupling relationship, constraints are constructed, and the flexibility evaluation objective function is solved based on the constraints 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 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. 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.

[0164] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to execute the flexibility assessment method for a steel plant energy supply system taking into account privacy protection and load uncertainty provided by the above-mentioned methods, the method comprising: 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 comprising a steam network description sub-model within the energy supply system, a power balance constraint description sub-model of the power sub-system, a steam enthalpy description sub-model, and an operation description sub-model of the energy supply equipment; obtaining an aggregated flexibility domain of the energy supply equipment provided by each plant area of ​​the steel plant to be evaluated, and constructing a fuel sub-model in the energy supply system based on the aggregated flexibility domain and the description model. The first coupling relationship between the system 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 domain of the energy supply equipment is obtained by aggregating the flexible domains of the same type of energy supply equipment; constraints are constructed based on the first coupling relationship and the second coupling relationship, and the flexibility evaluation objective function is solved based on the constraints 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 operating baseline data of the energy supply equipment. The operating baseline data of the energy supply equipment is obtained based on the historical operating 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.

[0165] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0166] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for 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.

[0167] 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 aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions 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, constraints are constructed, and the flexibility evaluation objective function is solved based on the constraints to obtain a flexibility evaluation result of the energy supply system. 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. 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.

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, characterized in that: The first coupling relationship is: ； The second coupling relationship is: ； in, 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, Indicates the number of gas types, 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.

4. The method for evaluating the flexibility of a steel plant energy supply system considering privacy protection and load uncertainty according to claim 3 is characterized in that: The flexibility evaluation objective function is: ； in, The solution result is the flexibility evaluation result. represents the controllable capacity of the energy supply system at time t, , , the variables of the objective function evaluated for said flexibility, is the operating status of each energy supply device 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, , denote the enthalpy of steam in the i-th and j-th layers of the steam network, respectively. 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.

5. The method for evaluating the flexibility of a steel plant energy supply system considering privacy protection and load uncertainty according to claim 1, 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.

6. The method for evaluating the flexibility of a steel plant energy supply system considering privacy protection and load uncertainty according to claim 1, 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.

7. 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 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, 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. 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.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: 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 6 is implemented.

9. 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 6 is implemented.

10. 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 6 is implemented.

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