Regulation and control system and design method of blast furnace wall structure

Abstract

The invention relates to a regulation and control system for a blast furnace wall structure and a design method, and belongs to the technical field of blast furnaces. The system comprises a furnace wall parameter regulation and control system and a coal gas flow regulation and control system. The furnace wall parameter regulation and control system calculates the minimum design thickness of the brick lining by calculating the limit thermal load of the cooling wall according to the temperature distribution in the furnace, so that the cooling wall is safe and reliable under the actual working condition. And the gas flow regulation and control system calculates temperature distribution in the furnace according to the furnace profile, the raw material conditions and the operation parameters and guides an operator to adjust the operation parameters, so that the furnace temperature distribution reaches a preset state, and the furnace condition is optimized. According to the method, the furnace wall structure design can be quantitatively evaluated and adjusted according to the given working conditions, and the gas flow state is evaluated according to the actual furnace wall structure characteristic temperature, so that the operation regulation direction is guided, and the production efficiency and safety of the blast furnace are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of blast furnaces and relates to a control system and a design method for a blast furnace wall structure. Background Art

[0002] The structure of the blast furnace wall is related to the longevity, stable production and high efficiency of the blast furnace. In the past, the design of the furnace wall was mainly based on the design specifications and manufacturing specifications of the furnace type and cooling wall. The thickness of the refractory material in front of the cooling wall is generally determined by combining the properties of the refractory material and the internal requirements. The design heat load of each section of the cooling wall is generally used to calculate the water temperature rise of the cooling water. There is no verification of whether the cooling wall body can withstand the corresponding design heat load. One of the problems solved by this control system is to evaluate and verify whether the designed cooling wall can withstand the corresponding heat load.

[0003] Another question is whether the cooling wall that meets the design heat load is safe under actual working conditions, which is determined by the actual heat load it bears. Therefore, the design of the furnace wall must not only make the cooling wall meet the design heat load, but also make the heat load borne by the cooling wall under actual working conditions not greater than the design heat load of the cooling wall. The actual heat load borne by the cooling wall determined by the design parameters is mainly determined by the temperature and flow rate of the coal gas flow and the thickness of the hot surface protective layer (refractory material, slag skin) of the cooling wall. This requires consideration of the matching problem of the thickness of the refractory material and the coal gas flow. Another problem solved by this control system is to ensure that the heat load borne by the cooling wall under actual working conditions is not greater than the design heat load of the cooling wall. Summary of the invention

[0004] In view of this, the purpose of the present invention is to provide a control system and design method for the blast furnace wall structure. The control system can quantitatively evaluate and adjust the furnace wall structure design according to given working conditions; it can evaluate the gas flow state according to the characteristic temperature of the actual blast furnace wall structure, and then guide the control direction of the operation.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] A control system for a blast furnace wall structure, comprising:

[0007] The furnace wall parameter control system is used to design the cooling wall equipment according to the furnace type and cooling wall design specifications and manufacturing technical requirements, calculate the ultimate heat load of the cooling equipment, and determine whether the designed cooling wall ultimate heat load reaches the set value. If not, adjust the design parameters to make the cooling wall ultimate heat load reach the set value;

[0008] The gas flow control system is used to calculate the temperature distribution in the blast furnace according to the blast furnace type, the set raw material conditions and the operating parameters, and determine whether the furnace temperature distribution reaches the preset state. If not, adjust the operating parameters to make the furnace temperature distribution reach the preset state;

[0009] The furnace wall parameter control system provides the coal gas flow control system with information on the furnace wall structure and material properties so that the coal gas flow control system can calculate the heat transfer process between the coal gas flow and the furnace wall; the coal gas flow control system provides the furnace wall parameter control system with information on the temperature distribution in the furnace and the coal gas flow rate so that the furnace wall parameter control system can evaluate whether the cooling wall can withstand the heat load under actual working conditions;

[0010] The furnace wall parameter control system optimizes the furnace wall structure design according to the information provided by the coal gas flow control system, so that the cooling wall can withstand the heat load under actual working conditions and extend the service life of the furnace wall; the coal gas flow control system adjusts the operating parameters and optimizes the coal gas flow distribution according to the furnace wall structure information provided by the furnace wall parameter control system, so that the furnace temperature distribution reaches the preset state, providing a calculation basis for the furnace wall parameter control system.

[0011] Furthermore, the control system of the furnace wall parameters also includes:

[0012] Calculate the minimum design thickness of the brick lining corresponding to each area according to the furnace temperature distribution and the ultimate heat load of the designed cooling wall;

[0013] Furthermore, the control system of the furnace wall parameters also includes:

[0014] The cooling walls of each area and the corresponding brick lining thickness are combined into the furnace wall.

[0015] A method for designing a furnace wall structure comprises the following steps:

[0016] 1) Determine the design of cooling wall equipment;

[0017] 2) Calculate the ultimate heat load of the cooling wall;

[0018] 3) Determine whether the designed cooling wall limit heat load reaches the set value;

[0019] 4) Calculate the temperature distribution in the blast furnace;

[0020] 5) Determine whether the furnace temperature distribution reaches the preset state;

[0021] 6) Calculate the minimum design thickness of brick lining corresponding to each area;

[0022] 7) Design the furnace wall structure.

[0023] Further, the step of determining the design of the cooling wall equipment includes:

[0024] Preliminarily determine the height, number of blocks and width of each section of cooling wall according to the furnace type;

[0025] Based on the manufacturing technology and design specifications of the cooling wall, the distance between the cooling wall water pipe and the edge, the pipe spacing, and the pipe diameter are preliminarily determined.

[0026] Further, the step of calculating the ultimate heat load of the cooling wall includes:

[0027] A CAE simulation model is established according to the geometric dimensions of each section of the cooling wall, the temperature field of the cooling wall with different heat loads is calculated, and the maximum temperature of the cooling wall is extracted. When the maximum temperature of the cooling wall is close to the temperature at which the phase change of the cooling wall material occurs, the corresponding heat load is the limit heat load of the cooling wall.

[0028] Further, the step of determining whether the designed cooling wall limit heat load reaches the set value comprises:

[0029] The set heat load used to calculate the water temperature rise of each section of the cooling wall is compared with the ultimate heat load value of the cooling wall section. If the ultimate heat load value of the cooling wall is greater than the set heat load value of the section, it means that the design parameters of the cooling wall are reasonable and can adapt to the set heat load value of the section. If the ultimate heat load value of the cooling wall is less than or equal to the set heat load value of the section, it means that the design parameters of the cooling wall are unreasonable and it is necessary to adjust the design parameters of the cooling wall within the range required by the specification. Repeat steps 1) to 3) until the ultimate heat load value of the cooling wall is greater than the set heat load value of the section.

[0030] Further, the step of calculating the temperature distribution in the blast furnace includes:

[0031] Calculate the distribution of gas flow according to the blast furnace type, raw material conditions and the initially set operating parameters;

[0032] According to the distribution of coal gas flow, based on the heat transfer characteristics of coal gas flow and furnace charge, and using the water equivalent balance relationship between coal gas and furnace charge, the temperature distribution of coal gas and furnace charge is calculated.

[0033] Further, the step of determining whether the furnace temperature distribution reaches a preset state includes:

[0034] Determine the furnace temperature distribution, such as whether the soft melting zone is located in the upper area of ​​the furnace waist and furnace belly. If not, adjust the operating parameters and repeat steps 4) to 5) until the furnace temperature distribution reaches the predetermined state.

[0035] Further, the step of calculating the minimum design thickness of the brick lining corresponding to each area includes:

[0036] The geometric dimensions of the cooling wall whose heat load limit value reaches the set value in step 3) are used as the model basis;

[0037] The furnace temperature corresponding to each section of the cooling wall is used as the boundary condition for the cooling wall simulation calculation;

[0038] Calculate the temperature distribution of the cooling wall corresponding to different brick lining thicknesses;

[0039] When the maximum temperature of the cooling wall reaches the maximum temperature of the cooling wall corresponding to the designed cooling wall limit heat load, the corresponding brick lining thickness is the minimum design thickness of the brick lining;

[0040] The steps of designing the furnace wall structure include:

[0041] Combined with the requirements of blast furnace internal design, the actual designed brick lining thickness can be greater than or equal to the minimum brick lining thickness;

[0042] The cooling walls of each area and the corresponding brick lining thickness are combined to form a furnace wall construction scheme that meets the thermal load requirements of the blast furnace.

[0043] The beneficial effects of the present invention are:

[0044] (1) By calculating the ultimate heat load of the cooling wall, the present invention can evaluate whether the cooling wall can withstand the heat load under actual working conditions, thereby avoiding damage to the cooling wall due to overheating and extending the service life of the cooling wall.

[0045] (2) According to the temperature distribution in the furnace and the ultimate heat load of the cooling wall, the present invention can calculate the minimum design thickness of the brick lining corresponding to each area, ensure the safety and reliability of the cooling wall under actual working conditions, and avoid safety accidents such as furnace wall burn-through.

[0046] (3) By calculating the temperature distribution in the furnace, the present invention can guide the operator to adjust the operating parameters and optimize the gas flow distribution so that the furnace temperature distribution reaches a preset state, thereby improving the stability of the furnace condition and reducing the fluctuation of the furnace condition.

[0047] Optimization of furnace wall structure: The present invention can optimize the furnace wall structure design according to the temperature distribution in the furnace and the ultimate heat load of the cooling wall, making the furnace wall structure more reasonable and adaptable, thereby improving the stability of blast furnace operation.

[0048] (4) By improving the safety and stability of the furnace wall, the present invention can extend the service life of the blast furnace, reduce the number of blast furnace shutdowns for maintenance, and improve the production efficiency of the blast furnace.

[0049] (5) The present invention can evaluate the state of coal gas flow according to the actual characteristic temperature of the furnace wall structure, and then guide the operation and control direction, so that the operator can control the blast furnace condition more accurately and improve the operation efficiency.

[0050] (6) By extending the service life of the blast furnace and reducing the number of blast furnace shutdowns for maintenance, the present invention can reduce the maintenance cost of the blast furnace. By improving the production efficiency of the blast furnace and reducing the maintenance cost, the present invention can improve the economic benefits of the blast furnace.

[0051] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0053] Figure 1 This is the furnace size drawing;

[0054] Figure 2 To design the cooling wall scheme;

[0055] Figure 3 The heat load of the hot surface is 50000w / m 2 The corresponding cooling wall temperature;

[0056] Figure 4 The heat load of the hot surface is 50000w / m 2 Corresponding heat flux distribution of cooling wall;

[0057] Figure 5 The temperature diagram of edge gas and furnace charge when the edge gas flow rate is the average gas flow in the furnace;

[0058] Figure 6 The cooling wall temperature diagram for the B3 section when the gas flow heating surface temperature is 1000℃;

[0059] Figure 7 It is the furnace wall structural plan;

[0060] Figure 8 Design a flow chart for the furnace wall. DETAILED DESCRIPTION

[0061] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0062] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0063] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0064] The implementation process of the patent is explained by taking the design of the furnace wall of the B3 section of a blast furnace as an example. The known design conditions are as follows:

[0065] 1) Furnace internal dimensions such as Figure 1 As shown. The diameter of the furnace throat is 8200mm, and the height of the furnace throat is 1800mm. The height of the furnace body is 15600mm. The diameter of the furnace waist is 13750mm, and the height is 1800mm. The height of the furnace belly is 3800mm. The diameter of the furnace hearth is 11300, and the height is 4938mm.

[0066] 2) The design heat load of the cooling wall is shown in Table 1.

[0067] Table 1

[0068]

[0069] 3) Raw materials and operating conditions

[0070] The raw materials are shown in Table 2.

[0071] Table 2

[0072]

[0073]

[0074] The smelting process parameters are shown in Table 3.

[0075] Table 3

[0076]

[0077] The air blast parameters are shown in Table 4.

[0078] Table 4

[0079] <![CDATA[Oxygen content ω, m in the wind 3 / m 3 Dry wind]]> 0.23 <![CDATA[Moisture in the wind, m 3 / m 3 > 0 Wind temperature, ℃ 1250 <![CDATA[Wind pressure P 风 , Pa]]> 368820 Oxygen enrichment rate 0.02

[0080] 3) Standards used

[0081] YB / T4073-2007 Cast iron cooling stave for blast furnace; GB / T 1348-2019 Ductile iron castings, etc.

[0082] Design steps of furnace wall structure:

[0083] 1. Determine the preliminary design plan for the cooling wall equipment

[0084] 1) Number of initial cooling staves

[0085] Section B3 is located at the furnace waist. The number of circumferential blocks of the cooling wall is initially determined based on past configuration experience.

[0086] Center diameter of cooling water pipe: 13750+100*2+(70+80)*2=14250mm; 100mm is the thickness of full brick, 70mm is the rib height, and 80mm is the distance from the center of the cooling water pipe to the bottom of the rib.

[0087] The number of cooling staves is preliminarily estimated based on the width of one cooling stave being 900mm, π*14250 / 900=49.7 pieces. An even number of pieces is taken. Considering that the water head number is consistent with that of the adjacent bosh and furnace body cooling staves, 48 ​​pieces are temporarily taken.

[0088] 2) Design cooling wall scheme

[0089] Design cooling wall scheme Figure 2 shown.

[0090] 2. Calculate the ultimate heat load of the cooling wall

[0091] Based on the design diagram of the cooling wall as the geometric model, the cooling wall is calculated at 50000w / m 2 The maximum temperature of the cooling wall is 678℃, which is lower than the phase transition temperature of cast iron 706℃, indicating that the ultimate heat load of the cooling wall is slightly greater than 50000w / m 2 .

[0092] Heating surface heat load 50000w / m 2 The corresponding cooling wall temperature is Figure 3 The heat flux distribution of the cooling wall corresponding to the heat load of the hot surface of 50000w / m2 is as follows Figure 4 shown.

[0093] 3. Determine whether the designed cooling wall limit heat load reaches the set value

[0094] The design heat load of section B3 in the known conditions is 48837w / m 2 The designed cooling wall limit heat load is 50000w / m 2 , has reached the design value (if not, the cooling water pipe diameter can be adjusted or the pipe spacing can be reduced by increasing the number of blocks on the circumference of the cooling wall while meeting the standard specifications).

[0095] 4. Calculate the temperature distribution in the blast furnace

[0096] If the edge gas flow rate is the average flow rate in the furnace, the edge gas and charge temperatures are Figure 5 As shown, the gas flow and charge temperature distribution in the furnace between the 0-charge line and the center line of the tuyere can be seen.

[0097] 5. Determine whether the furnace temperature distribution reaches the preset state

[0098] The starting temperature of the soft melting zone is 1050℃ at the junction of the furnace waist and the furnace belly. From the perspective of the longevity of the cooling wall, this furnace temperature distribution is appropriate. If the edge gas flow is developed and the edge gas flow is too strong, 1050℃ may be above the furnace body. In this case, the edge gas flow should be controlled to keep the temperature of the soft melting zone below the furnace waist (here only from the perspective of the longevity of the cooling wall. If such a gas flow distribution cannot be achieved in actual operation, it should be considered to achieve safe operation of the cooling wall by adjusting the thickness of the brick lining under actual working conditions).

[0099] 6. Calculate the minimum design thickness of brick lining corresponding to each area

[0100] We can use trial calculation to add 60mm brick lining to the hot surface of B3 cooling wall. The hot surface temperature of gas flow corresponding to B3 section is 1000℃. Under this condition, the maximum temperature of cooling wall is calculated to be 628℃. Figure 6 As shown, it is lower than 700℃ (calculated that the maximum temperature of the cooling wall is 714℃ with 50mm brick lining in front), which means it is appropriate to set a brick lining of ≥60mm in front of the cooling wall.

[0101] 7. Furnace wall structure design

[0102] According to the cooling wall design and brick lining thickness, the B3 section furnace wall design is formed, see Figure 7 shown.

[0103] Furnace wall design process Figure 8 shown.

[0104] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. A control system for a blast furnace wall structure, characterized in that: include: The furnace wall parameter control system is used to design the cooling wall equipment according to the furnace type and cooling wall design specifications and manufacturing technical requirements, calculate the ultimate heat load of the cooling equipment, and determine whether the designed cooling wall ultimate heat load reaches the set value. If not, adjust the design parameters to make the cooling wall ultimate heat load reach the set value; The gas flow control system is used to calculate the temperature distribution in the blast furnace according to the blast furnace type, the set raw material conditions and the operating parameters, and determine whether the furnace temperature distribution reaches the preset state. If not, adjust the operating parameters to make the furnace temperature distribution reach the preset state; The furnace wall parameter control system provides the coal gas flow control system with information on the geometric dimensions and material properties of the furnace wall structure, so that the coal gas flow control system can calculate the heat transfer process between the coal gas flow and the furnace wall; at the same time, the coal gas flow control system provides the furnace wall parameter control system with information on the temperature distribution in the furnace and the coal gas flow rate, so that the furnace wall parameter control system can evaluate whether the cooling wall can withstand the heat load under actual working conditions; The furnace wall parameter control system optimizes the furnace wall structure design according to the information provided by the coal gas flow control system, so that the cooling wall can withstand the heat load under actual working conditions and extend the service life of the furnace wall; the coal gas flow control system adjusts the operating parameters and optimizes the coal gas flow distribution according to the furnace wall structure information provided by the furnace wall parameter control system, so that the furnace temperature distribution reaches the preset state, providing a calculation basis for the furnace wall parameter control system.

2. The control system for blast furnace wall structure according to claim 1, characterized in that: The control system of the furnace wall parameters also includes: The minimum design thickness of the brick lining corresponding to each area is calculated based on the furnace temperature distribution and the ultimate heat load of the designed cooling wall.

3. The control system for blast furnace wall structure according to claim 2, characterized in that: The control system of the furnace wall parameters also includes: The cooling walls of each area and the corresponding brick lining thickness are combined into the furnace wall.

4. A method for designing a furnace wall structure, characterized in that: The following steps are involved: 1) Determine the design of cooling wall equipment; 2) Calculate the ultimate heat load of the cooling wall; 3) Determine whether the designed cooling wall limit heat load reaches the set value; 4) Calculate the temperature distribution in the blast furnace; 5) Determine whether the furnace temperature distribution reaches the preset state; 6) Calculate the minimum design thickness of brick lining corresponding to each area; 7) Design the furnace wall structure.

5. The method for designing a furnace wall structure according to claim 4, characterized in that: The step of determining the design of the cooling wall equipment comprises: Preliminarily determine the height, number of blocks and width of each section of cooling wall according to the furnace type; Based on the manufacturing technology and design specifications of the cooling wall, the distance between the cooling wall water pipe and the edge, the pipe spacing, and the pipe diameter are preliminarily determined.

6. The method for designing a furnace wall structure according to claim 4, characterized in that: The step of calculating the ultimate heat load of the cooling wall comprises: A CAE simulation model is established according to the geometric dimensions of each section of the cooling wall, the temperature field of the cooling wall with different heat loads is calculated, and the maximum temperature of the cooling wall is extracted. When the maximum temperature of the cooling wall is close to the temperature at which the phase change of the cooling wall material occurs, the corresponding heat load is the limit heat load of the cooling wall.

7. The method for designing a furnace wall structure according to claim 4, characterized in that: The step of judging whether the designed cooling wall limit heat load reaches the set value comprises: The set heat load used to calculate the water temperature rise of each section of the cooling wall is compared with the ultimate heat load value of the cooling wall section. If the ultimate heat load value of the cooling wall is greater than the set heat load value of the section, it means that the design parameters of the cooling wall are reasonable and can adapt to the set heat load value of the section. If the ultimate heat load value of the cooling wall is less than or equal to the set heat load value of the section, it means that the design parameters of the cooling wall are unreasonable and it is necessary to adjust the design parameters of the cooling wall within the range required by the specification. Repeat steps 1) to 3) until the ultimate heat load value of the cooling wall is greater than the set heat load value of the section.

8. The method for designing a furnace wall structure according to claim 4, characterized in that: The step of calculating the temperature distribution in the blast furnace comprises: Calculate the distribution of gas flow according to the blast furnace type, raw material conditions and the initially set operating parameters; According to the distribution of coal gas flow, based on the heat transfer characteristics of coal gas flow and furnace charge, and using the water equivalent balance relationship between coal gas and furnace charge, the temperature distribution of coal gas and furnace charge is calculated.

9. The method for designing a furnace wall structure according to claim 4, characterized in that: The step of determining whether the furnace temperature distribution reaches a preset state comprises: Determine the furnace temperature distribution, such as whether the soft melting zone is located in the upper area of ​​the furnace waist and furnace belly. If not, adjust the operating parameters and repeat steps 4) to 5) until the furnace temperature distribution reaches the predetermined state.

10. The method for designing a furnace wall structure according to claim 4, characterized in that: The step of calculating the minimum design thickness of the brick lining corresponding to each area includes: The geometric dimensions of the cooling wall whose heat load limit value reaches the set value in step 3) are used as the model basis; The furnace temperature corresponding to each section of the cooling wall is used as the boundary condition for the cooling wall simulation calculation; Calculate the temperature distribution of the cooling wall corresponding to different brick lining thicknesses; When the maximum temperature of the cooling wall reaches the maximum temperature of the cooling wall corresponding to the designed cooling wall limit heat load, the corresponding brick lining thickness is the minimum design thickness of the brick lining; The steps of designing the furnace wall structure include: Combined with the requirements of blast furnace internal design, the actual designed brick lining thickness is greater than or equal to the minimum brick lining thickness; The cooling walls of each area and the corresponding brick lining thickness are combined to form a furnace wall construction scheme that meets the thermal load requirements of the blast furnace.

Images