An electrolytic aluminum load modeling and energy consumption calculation method based on whole-process coupling

Abstract

The application discloses a kind of based on full-process coupling's electrolytic aluminium load modeling and energy consumption calculation method, belongs to industrial load technical field, by analyzing the full-process production process of electrolytic aluminium load, the production process of electrolytic aluminium load is divided into three links of distribution raw material, electrolysis, aluminum, and is analyzed by the heat, electricity and yield balance relationship between production process, and the corresponding mathematical model is established for three processes respectively, and finally the full-process coupling production model of electrolytic aluminium load considering time infinitesimal is established.The application can provide a more accurate electrolytic aluminium load model, obtain more close actual electrolytic aluminium load power consumption, improve the accuracy of electrolytic aluminium load model, and provide basis for electrolytic aluminium load participating demand response.

Description

Technical Field

[0001] This invention belongs to the field of industrial load technology, and in particular relates to a multi-timescale modeling method for electrolytic aluminum load based on full-process coupling and its energy consumption calculation method. Background Technology

[0002] Electrolytic aluminum load is a significant industrial load in my country. High energy consumption is a prominent characteristic of electrolytic aluminum load; a single electrolytic aluminum plant can have a capacity of hundreds of megawatts, making its participation in grid demand response highly feasible and promising. The adjustability of electrolytic aluminum load depends on its entire production process; describing the physical coupling characteristics of each production process stage is fundamental to accurately characterizing its physical adjustability boundary and demand response characteristics. Constructing a fully coupled electrolytic aluminum load model is a modeling approach based on the coupling relationships between various stages of the electrolytic aluminum load in actual operation and considering the influence of multiple time scales. However, in practical engineering applications, the modeling of multi-production-process electrolytic aluminum loads is generally coarse, and such models increasingly fail to meet the needs of actual engineering projects.

[0003] Therefore, existing technologies urgently need a new technical solution to address the above problems. Summary of the Invention

[0004] The technical problem to be solved by this invention is to provide a method for modeling and calculating the load of electrolytic aluminum based on full-process coupling, to provide a more accurate electrolytic aluminum load model, to obtain a power consumption of electrolytic aluminum load that is closer to the actual load, to improve the accuracy of the electrolytic aluminum load model, and to provide a basis for electrolytic aluminum load to participate in demand response.

[0005] A method for load modeling and energy consumption calculation in electrolytic aluminum based on full-process coupling, characterized by the following steps:

[0006] Step 1: Establish production models for each stage of the electrolytic aluminum process, including a raw material delivery production model, an electrolysis production model, an aluminum tapping production model, and an electrolysis reaction rate model.

[0007] Step 2: Input the DC power P0 of the electrolytic cell, the power P1 of the conveyor belt motor, and the vacuum lifting power P2 into the model established in Step 1 for calculation to obtain the alumina content and the aluminum liquid content in the cell, and determine whether the alumina content and the aluminum liquid content in the cell meet the safe operation constraints.

[0008] Step 3: If the safety operation constraints are met, the adjustment is complete. If the safety operation constraints are not met, change P1 and repeat the calculation process until the safety operation constraints are met, and obtain the total power consumption when adjusting the delivery rate of raw materials.

[0009] The production model for delivering raw materials in step one includes the power consumption of delivering raw materials and the amount of alumina raw materials in the tank; the production model for the electrolysis part includes the heat balance in the electrolytic cell during the electrolysis process, the heat loss of the cell, the heat required to heat the alumina raw materials, and the heat required for the reaction; the production model for the aluminum tapping part includes the power consumption of the aluminum tapping process and the amount of molten aluminum in the tank.

[0010] The power consumption of the delivered raw materials is:

[0011]

[0012] In the formula: Let t be the power consumption for delivering raw materials. For the rate of delivery of raw materials, E del The electricity consumption per ton of alumina delivered.

[0013] The power consumption of the aluminum tapping process is:

[0014]

[0015] In the formula: Let t be the power consumption for lifting aluminum. E represents the aluminum extraction rate. pre The amount of heat required to lift out each ton of aluminum in the reaction.

[0016] The thermal balance within the electrolytic cell during the electrolysis process is as follows:

[0017]

[0018] In the formula: Let be the DC power at time t. Let t be the heat loss of the tank. Let t be the amount of heat required to heat the alumina raw material. Let c be the heat required for the reaction at time t. elt m is the specific heat capacity of the electrolyte. elt Where is the mass of the electrolyte, and T is the reaction temperature.

[0019] Through the above design scheme, the present invention can bring the following beneficial effects: a method for modeling and calculating the load of electrolytic aluminum based on full-process coupling, which considers the entire production process of electrolytic aluminum load and the coupling relationship between each production process, breaks through the traditional load modeling method that only targets the electrolytic process of electrolytic aluminum load, and uses the time infinitesimal method to calculate and analyze the power consumption of electrolytic aluminum load, so as to fully explore its load regulation potential. Attached Figure Description

[0020] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0021] Figure 1This is a schematic diagram of the process of a method for load modeling and energy consumption calculation of electrolytic aluminum based on full-process coupling according to the present invention.

[0022] Figure 2 This is a comparison chart of the total power consumption under different conditions: without adjusting the raw material delivery rate and with adjusting the raw material delivery rate, according to a specific implementation method of the present invention for load modeling and energy consumption calculation of electrolytic aluminum based on full-process coupling. Detailed Implementation

[0023] A method for load modeling and energy consumption calculation in electrolytic aluminum based on full-process coupling, such as... Figure 1 As shown, this is achieved through the following process:

[0024] 1. Establish production models for each stage of electrolytic aluminum production:

[0025] 1.1 Production Model for Raw Material Distribution

[0026] 1.1.1 Power consumption for delivering raw materials:

[0027]

[0028] In the formula: P t Al2o3 v represents the electricity consumption for delivering raw materials at time t. t in For the rate of delivery of raw materials, E del The electricity consumption per ton of alumina delivered.

[0029] 1.1.2 Alumina raw material inventory in the tank:

[0030]

[0031] Where: m t+1 Al2o3 Let m be the alumina stock at time t+1. t Al2o3 v represents the alumina stock at time t. t f denoted as the reaction rate.

[0032] 1.2 Electrolysis Production Model

[0033] 1.2.1 Thermal balance within the electrolytic cell during the electrolysis process:

[0034]

[0035] In the formula: q t e Let q be the DC power at time t. t rad Let q be the heat loss of the tank at time t. t AL2O3Let q be the amount of heat required to heat the alumina raw material at time t. t rea Let c be the heat required for the reaction at time t. elt m is the specific heat capacity of the electrolyte. elt Where is the mass of the electrolyte, and T is the reaction temperature.

[0036] 1.2.2 Heat loss from the tank:

[0037]

[0038] Where: h elt T is the heat dissipation coefficient. room For indoor temperature, A elt This refers to the heat dissipation area of ​​the tank.

[0039] 1.2.3 Heat required to heat alumina raw materials:

[0040]

[0041] In the formula: E AL2O3 The amount of heat required to heat each ton of alumina to the reaction temperature.

[0042] 1.2.4 Heat required for the reaction

[0043]

[0044] In the formula: E rea The amount of heat required to react one ton of alumina.

[0045] 1.3 Production Model for Aluminum Extraction Section

[0046] 1.3.1 Power consumption during the aluminum tapping process:

[0047]

[0048] In the formula: P t Al Let v be the power consumption for lifting aluminum at time t. t out E represents the aluminum extraction rate. pre The amount of heat required to lift out each ton of aluminum in the reaction.

[0049] 1.3.2 Aluminum liquid inventory in the tank:

[0050]

[0051]

[0052] Where: m t+1 Al Let m be the volume of molten aluminum at time t+1. t Al2o3Let w be the amount of molten aluminum at time t, and w be a variable between 0 and 1, which is 1 when vacuum lifting is performed, and 0 otherwise.

[0053] 1.4 Electrolysis Reaction Rate Model

[0054]

[0055]

[0056] In the formula: η t Let η be the reaction efficiency at time t. max For the maximum reaction efficiency, α, k, and b are constants.

[0057] 2. Calculate the power consumption of the electrolytic aluminum load:

[0058] ① Input DC power to the electrolytic cell Conveyor motor power Vacuum lifting power

[0059] ② Input into equation (1) to determine the rate of raw material delivery.

[0060] ③ Input into equation (7) to determine the aluminum extraction rate.

[0061] ④ Input the heat required to heat the alumina raw material into equation (5).

[0062] ⑤ Input into equation (3) to determine the reaction temperature T t T t+1 .

[0063] ⑥T t T t+1 Input into equation (11) to determine the reaction efficiency η t η t+1 .

[0064] ⑦ will η t η t+1 Input into equation (10) to determine the reaction rate.

[0065] ⑧ Input into equation (2) to determine the alumina content in the tank.

[0066] ⑨ will Input into equation (8) to determine the amount of molten aluminum in the tank.

[0067] ⑩ Determine whether the alumina and molten aluminum levels in the tank meet the safety operating constraints. If the constraints are not met, change the method. Repeat the above calculation steps to obtain a comparison chart of total power consumption when the material delivery rate is not adjusted and when the material delivery rate is adjusted, as shown in the figure. Figure 2 As shown.

Claims

1. A method for load modeling and energy consumption calculation of electrolytic aluminum based on full-process coupling, characterized by: Includes the following steps, Step 1: Establish production models for each stage of the electrolytic aluminum process, including a raw material delivery production model, an electrolysis production model, an aluminum tapping production model, and an electrolysis reaction rate model. The raw material delivery production model includes the power consumption of the delivered raw materials and the inventory of alumina raw materials in the tank. The electricity consumption for delivering raw materials is: （1） In the formula: Let t be the power consumption for delivering raw materials. For the rate of delivery of raw materials, E del Electricity consumption per ton of alumina delivered; The amount of alumina raw material in the tank is: （2） In the formula: The alumina stock at time t+1 Let t be the alumina stock. The reaction rate; The electrolysis part generation model includes the heat balance in the electrolytic cell during the electrolysis process, heat loss of the cell, heat required to heat the alumina raw material, and heat required for the reaction. The thermal equilibrium within the electrolytic cell during the electrolysis process is as follows: （3） In the formula: Let be the DC power at time t. Let t be the heat loss of the tank. Let t be the amount of heat required to heat the alumina raw material. Let be the heat required for the reaction at time t. The specific heat capacity of the electrolyte. Here, T represents the electrolyte mass, and T represents the reaction temperature. The heat loss of the tank is: （4） In the formula: For heat dissipation coefficient, Indoor temperature, This refers to the heat dissipation area of ​​the tank. The amount of heat required to heat the alumina raw material is: （5） In the formula: The amount of heat required to heat each ton of alumina to the reaction temperature; The heat required for the reaction is: （6） In the formula: The amount of heat required to react per ton of alumina; The production model for the aluminum tapping section includes the power consumption of the aluminum tapping process and the amount of molten aluminum in the tank. The power consumption during the aluminum tapping process is: （7） In the formula: Let t be the power consumption for lifting aluminum. For aluminum extraction rate, The amount of heat required to remove one ton of aluminum in the reaction; The amount of molten aluminum in the tank is: （8） （9） In the formula: The aluminum liquid volume at time t+1 Let t be the amount of molten aluminum at time t, and ԝ be a 0-1 variable, taking 1 when vacuum lifting is performed, and 0 otherwise. The electrolysis reaction rate model is as follows: （10） （11） In the formula: Let be the reaction efficiency at time t. For maximum reaction efficiency, α, k, and b are constants; Step 2: Input DC power into the electrolytic cell, i.e., DC power at time t. The power of the conveyor belt motor, i.e., the amount of heat required to heat the alumina raw material at time t. Vacuum lifting power, i.e., the power consumption for lifting aluminum at time t. ;Will Input into equation (1) to determine the rate of raw material delivery. , ;Will Input into equation (7) to determine the aluminum extraction rate. , ;Will , Input the heat required to heat the alumina raw material into equation (5). , ;Will Input into equation (3) to determine the reaction temperature. , ;Will , Input into equation (11) to determine the reaction efficiency. , ;Will , Input into equation (10) to determine the reaction rate. , ;Will , , , Input into equation (2) to determine the alumina content in the tank. , ;Will , , , Input into equation (8) to determine the amount of molten aluminum in the tank. , Determine whether the alumina and molten aluminum levels in the tank meet the safety operation constraints. Step 3: If the safety operation constraints are met, the adjustment is complete; otherwise, the changes are made. Repeat step two of the calculation process until the safe operation constraints are met, and obtain the total power consumption when adjusting the delivery rate of raw materials.

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