Vertical mill air inlet duct obtaining method and evaluation method based on topological optimization and volute guide

Abstract

The invention discloses a vertical mill air inlet duct obtaining method and evaluation method based on topological optimization and volute guide. At present, there is no standard and quantitative acquisition and evaluation processing mode for the air inlet duct of the vertical mill, and the evaluation method for the air inlet duct of the vertical mill comprises the following steps: after determining an internal fluid domain of the vertical mill in an original model, carrying out two-dimensional topology processing on the internal fluid domain of the vertical mill to form first composition data; after the first composition data is compared with the internal fluid domain of the vertical mill, corresponding data is determined as first composition optimization data at the minimum pressure loss value of a main machine, and the internal fluid domain of the vertical mill is guided by a volute to form second composition data; comparing the second composition data with the internal fluid domain of the vertical mill, determining corresponding data as second composition optimization data when the wind speed of the wind ring outlet and the wind speed of the main machine outlet are at the highest value in the uniform state, and establishing an ultimate model of the whole vertical mill according to the first composition optimization data and the second composition optimization data. And performing a grading evaluation process on the ultimate model by adopting a steady-state solving method.

Description

Technical Field

[0001] The present invention specifically relates to a method for obtaining and evaluating the air inlet duct of a vertical mill based on topological optimization and volute guidance. Background Art

[0002] A vertical mill is an essential powder particle classification device in mining grinding equipment. Also known as a vertical roller mill, it is a grinding device that integrates multiple production processes such as crushing, grinding, drying, conveying, and powder selection. It has the advantages of low noise, high grinding efficiency, simple process flow, low power consumption, and adjustable grinding fineness. With the rapid development of high-tech industries, ultrafine powders have been applied in multiple industries such as chemical engineering, construction, and food. The quality requirements for ultrafine powders in each industry are also getting higher and higher. With the requirement of energy-saving transformation of equipment in the grinding field, as one of the most important grinding devices, enterprises are paying more and more attention to the energy-saving transformation of vertical mills. However, at present, the research on vertical mills in China is mostly limited to the research on the structure, and there is a lack of a clear understanding of the internal flow field and actual production laws of vertical mills. During the production process, the powder classification efficiency has always been the focus of research by various enterprises, but the importance of the main body of the vertical mill has been ignored. The materials inside the mill are driven by the airflow to rise and be classified, and the internal structure of the main body of the vertical mill directly affects the velocity distribution of the gas flow field. The velocity of the airflow at the outlet of the air ring directly affects the output of the vertical mill. If the velocity here is too small, the airflow cannot blow up enough material particles that meet the particle size requirements, resulting in an increase in the circulating load of the vertical mill and a decrease in the powder selection efficiency; if the velocity here is too large, it will cause the phenomenon of coarse particles in the powder separator, affecting the product quality. Moreover, a large number of coarse particles will fall back into the grinding table along the ash hopper when passing through the centrifugal fan area for grinding again, increasing the screening volume and equipment wear of the classifier part, and at the same time increasing the energy consumption. At present, there is a lack of a quantitative and standardized evaluation method for the pressure loss of the main body of the vertical mill, and there is no standardized processing method that can simultaneously evaluate the velocity uniformity at the outlet of the air ring and the outlet of the main body inside the vertical mill, resulting in an inaccurate evaluation of the grinding and energy consumption conditions of the vertical mill in use, and it is also impossible to give a quantitatively accurate improvement method. Summary of the Invention

[0003] In order to overcome the defects of the prior art, a method for obtaining and evaluating the air inlet duct of a vertical mill based on topological optimization and volute guidance is provided to solve the above problems.

[0004] A method for obtaining the air inlet duct of a vertical mill based on topology optimization and volute guidance. The method for obtaining the air inlet duct of the vertical mill is as follows: after determining the internal fluid domain of the vertical mill in the original model, the internal fluid domain of the vertical mill is processed through two-dimensional topology to form the first set of component data. After comparing the first set of component data with the internal fluid domain of the vertical mill, the corresponding data at the lowest main machine pressure loss is determined as the first set of optimized data. The internal fluid domain of the vertical mill is processed through volute guidance to form the second set of component data. After comparing the second set of component data with the internal fluid domain of the vertical mill, the corresponding data at the highest value when the wind ring outlet and the main machine outlet wind speeds are in a uniform state is determined as the second set of optimized data. The ultimate model of the entire vertical mill is established based on the first set of optimized data and the second set of optimized data.

[0005] As a preferred solution: the original model is established by collecting mill data. The process of using the internal fluid domain of the vertical mill in the original model is to simplify the design scheme model through the Space Claim module provided by the ANSYS workbench platform to form a simplified model, extract the internal fluid domain of the vertical mill from the simplified model, and create the internal fluid domain of the vertical mill after naming each boundary in the simplified model.

[0006] As a preferred solution: the process of forming the first set of component data by processing the internal fluid domain of the vertical mill through two-dimensional topology, and determining the corresponding data at the lowest main machine pressure loss as the first set of optimized data after comparing the first set of component data with the internal fluid domain of the vertical mill is to mesh the internal fluid domain of the vertical mill through Fluent meshing. After the meshing is completed, primary data is formed. The primary data is set with simulation operation parameters to form secondary data. The secondary data is processed through two-dimensional topology optimization on the COMSOL platform to form the first set of component data. According to the theoretical standard value of the internal data of the vertical mill, the first set of component data is compared with the internal fluid domain of the vertical mill, and the data in the first set of component data corresponding to the lowest main machine pressure loss is determined as the first set of optimized data.

[0007] As a preferred solution: the calculation process of forming the first set of component data by processing the internal fluid domain of the vertical mill through two-dimensional topology is to optimize and solve the topology optimization mathematical model using the IPOP algorithm in the optimization solver. The conditions for topological optimization convergence are:

[0008] max|θ pi -θ pi-1 |≤E

[0009] Where, θ pi is the value of the design variable in the current iteration process, and θ pi-1 is the value of the design variable in the previous iteration process; E is the optimization tolerance;

[0010] The objective function of topology optimization is to minimize the pressure loss within the design domain, and its expression is:

[0011] PP = aveop1(p) - aveop2(p)

[0012] where PP is the average pressure loss within the domain, aveop1(p) is the inlet pressure, and aveop2(p) is the outlet pressure;

[0013] The constraint condition of topology optimization is the flow channel volume interval, and its expression is:

[0014] s11 = intop1(dtopo1.theta) * t1 = ∫ Ω (dtopo1.theta) * t1d Ω

[0015] s11 min ≤ ∫ Ω (dtopo1.theta) * t1d Ω ≤ s11 max

[0016] where Ω is the design domain, s11 min is the lower bound of the average volume factor, s11 max is the upper bound of the average volume factor;

[0017] The mathematical model of the flow channel topology optimization is expressed as:

[0018] Find: θ pi (i = 1, 2,..., n), θ c = [0, 1]

[0019] Minimize: PP = aveop1(p) - aveop2(p)

[0020] Subject to: θ c = [0, 1]

[0021]

[0022] s11 min ≤ ∫ Ω (dtopo1.theta) * t1d Ω ≤ s11 max

[0023] where, θ c is the design variable of topology optimization, i is the subscript of each design variable, q is the penalty coefficient in the difference model, s11 min is the lower bound of the average volume factor, s11 maxis the upper bound of the average volume factor; the topology optimization result is the target probe calculation for the pressure drop at the inlet and outlet of the air inlet. Through topology optimization, the target probe result of the pressure drop at the inlet and outlet of the air inlet is obtained, the lowest value of the main machine pressure loss corresponding to the optimization solution is obtained, and finally the two-dimensional cross-section topology optimization result of the vertical mill is obtained.

[0024] As a preferred solution: After the internal fluid domain of the vertical mill is guided by the volute to form the second set of data, when the highest value is reached under the condition that the wind ring outlet and the main machine outlet wind speeds are in a uniform state after comparing the second set of data with the internal fluid domain of the vertical mill, the corresponding data is determined as the second set of optimized data. The process is to form a three-dimensional main machine bottom shell of the vertical mill through Solidworks modeling. The wind ring outlet and the main machine outlet wind speed data of the main machine bottom shell of the vertical mill are guided by the volute to form the second set of data. In the second set of data, the corresponding data when the highest value is reached under the condition that the wind ring outlet and the main machine outlet wind speeds are in a uniform state is used as the second set of optimized data.

[0025] A method for evaluating the air inlet duct of a vertical mill based on topology optimization and volute guidance. The method for evaluating the air inlet duct of a vertical mill is to determine the internal fluid domain of the vertical mill in the original model, and after two-dimensional topology processing of the internal fluid domain of the vertical mill, the first set of data is formed. After comparing the first set of data with the internal fluid domain of the vertical mill, the corresponding data is determined as the first set of optimized data when the main machine pressure loss is the lowest. After the internal fluid domain of the vertical mill is guided by the volute to form the second set of data, after comparing the second set of data with the internal fluid domain of the vertical mill, the corresponding data is determined as the second set of optimized data when the highest value is reached under the condition that the wind ring outlet and the main machine outlet wind speeds are in a uniform state. An ultimate model of the entire vertical mill is established based on the first set of optimized data and the second set of optimized data, and a hierarchical evaluation process is carried out on the ultimate model using a steady-state solution method.

[0026] As a preferred solution: The ultimate model is a DPM model. The process of carrying out a hierarchical evaluation of the ultimate model using a steady-state solution method is a process of analyzing the particle collection efficiency and corresponding analysis and rating of the particle upward movement trajectory based on the DPM model. The process of carrying out a hierarchical evaluation of the ultimate model is to determine energy consumption, the uniformity of the wind ring outlet wind speed, and the particle collection efficiency as three indicators under the condition that the vertical mill operating parameters are the same. The energy consumption, the uniformity of the wind ring outlet wind speed, and the particle collection efficiency of the ultimate model and the original model are respectively compared. When the reduction ratio of the energy consumption of the ultimate model compared to the original model is equal to or lower than 18.78%, the uniformity of the wind speed cloud map at the wind ring outlet of the ultimate model compared to the original model is improved, and the 200-mesh particle collection efficiency of the ultimate model compared to the original model reaches more than 90%, it indicates that under the condition that the vertical mill operating parameters are the same, the ultimate model obtained by optimizing the structural parameters of the vertical mill is superior to the original model.

[0027] As a preferred solution: Under the condition that the structural parameters of the vertical mill are the same and the single operating parameter of the air inlet speed of the vertical mill inlet air duct is different, with the collection efficiency of 200-mesh particles reaching over 90% as the evaluation standard, when the air inlet speed of the ultimate model inlet air duct decreases from 34 m / s to 18 m / s, the collection efficiency of 200-mesh particles can still reach over 90%. At this time, the energy consumption reduction ratio of the ultimate model compared to the original model is lower than 53.45%, indicating that the ultimate model is superior to the original model.

[0028] The beneficial effects of the present invention are as follows:

[0029] 1. The method for obtaining the air inlet duct of the vertical mill based on topology optimization and volute guidance in the present invention is a method specifically adapted for the air inlet duct of the vertical mill. Through the double-composite processing method of topology optimization and volute guidance, the relevant data of the air inlet duct of the vertical mill are obtained and optimized, and the optimal data at the lowest value of the main machine pressure loss and the highest value when the wind ring outlet and the main machine outlet air speeds are in a uniform state are determined. Based on the optimal data, the ultimate model of the entire vertical mill is obtained, and the ultimate model is the optimal model.

[0030] 2. The method for evaluating the air inlet duct of the vertical mill based on topology optimization and volute guidance in the present invention is an evaluation method for the air inlet duct of the vertical mill. Through the double-composite processing method of topology optimization and volute guidance, the relevant data of the air inlet duct of the vertical mill are obtained and optimized, and the optimal data at the lowest value of the main machine pressure loss and the highest value when the wind ring outlet and the main machine outlet air speeds are in a uniform state are determined. Based on the optimal data, the ultimate model of the entire vertical mill is obtained. After the ultimate model is determined, the steady-state solution method is used to conduct a hierarchical evaluation of the ultimate model, and then the grinding and energy consumption conditions of the vertical mill in use are accurately evaluated correspondingly, which is conducive to putting forward quantitative and accurate corresponding improvement measures for the vertical mill that has been put into use, and can also give optimization guidance opinions on the air inlet duct structure of the new vertical mill model that has not been actually built. Description of the Drawings

[0031] Figure 1 is the processing flow chart of the vertical mill model;

[0032] Figure 2 is the front view structural schematic diagram of the vertical mill;

[0033] Figure 3-1 is the schematic diagram of the average speed in the X-Y plane in the overall speed cloud map of the vertical mill;

[0034] Figure 3-2 is the schematic diagram of the speed trace line in the overall speed cloud map of the vertical mill;

[0035] Figure 4 is the X-Y plane average speed vector cloud map in the vertical mill;

[0036] Figure 5-1It is the overall velocity schematic diagram in the velocity contour map at the air ring outlet; Figure 5-2 It is the Y-direction velocity schematic diagram in the velocity contour map at the air ring outlet;

[0037] Figure 6 It is the schematic diagram of the flow channel structure at the bottom of the vertical mill housing;

[0038] Figure 7 It is the process diagram of the COMSOL topology optimization process and the setting process of the core operations therein;

[0039] Figure 8 It is the schematic diagram of the two-dimensional geometric model constructed during the topology optimization process;

[0040] Figure 9 It is the schematic diagram of mesh generation;

[0041] Figure 10 It is the schematic diagram of the optimization solution process of the topology optimization mathematical model using the IPOP algorithm in the optimization solver. In the figure, the optimization solution = 76;

[0042] Figure 11 It is the schematic diagram of the geometric model when the optimization solution = 76;

[0043] Figure 12-1 It is the schematic diagram of the model before topology optimization;

[0044] Figure 12-2 It is the schematic diagram of the model after topology optimization;

[0045] Figure 13 It is the schematic diagram of the relative position between the outlet of the main vertical mill and the air ring outlet. In the figure, the upper red line position is the main mill outlet, and the lower red line position is the air ring outlet;

[0046] Figure 14-1 It is the average velocity contour map at the air ring outlet before topology optimization;

[0047] Figure 14-2 It is the average velocity contour map at the air ring outlet after topology optimization;

[0048] Figure 15-1 It is the Y-direction velocity contour map at the air ring outlet before topology optimization;

[0049] Figure 15-2 It is the Y-direction velocity contour map at the air ring outlet after topology optimization;

[0050] Figure 16-1 It is the velocity trace contour map of the main vertical mill before topology optimization;

[0051] Figure 16-2 It is the velocity trace contour map of the main vertical mill after topology optimization;

[0052] Figure 17-1 It is the schematic diagram of the top view structure of the volute in the original model;

[0053] Figure 17-2 It is a schematic top view structure of the bottom volute after being guided by the volute;

[0054] Figure 18-1 It is a schematic structure diagram of the original air ring;

[0055] Figure 18-2 It is a schematic structure diagram of the new air ring after being guided by the volute;

[0056] Figure 19-1 It is a schematic longitudinal sectional structure diagram of the connection relationship between the bottom housing and the air ring in the original model;

[0057] Figure 19-2 It is a schematic longitudinal sectional structure diagram of the connection relationship between the bottom housing and the air ring in the ultimate model after being guided by the volute;

[0058] Figure 20-1 It is the average velocity contour map of the air ring outlet in the original model;

[0059] Figure 20-2 It is the average velocity contour map of the air ring outlet in the ultimate model after being guided by the volute;

[0060] Figure 21-1 It is the Y - direction velocity contour map of the air ring outlet in the original model;

[0061] Figure 21-2 It is the Y - direction velocity contour map of the air ring outlet after being guided by the volute;

[0062] Figure 22-1 It is the particle trace contour map of the main vertical mill in the original model;

[0063] Figure 22-2 It is the particle trace contour map of the main vertical mill in the ultimate model.

[0064] In the figure: 1 - First air inlet; 2 - Grinding table; 3 - Grinding roller; 4 - Hopper; 5 - Static vane; 6 - Fine powder outlet; 7 - Moving vane; 8 - Housing; 9 - Feed inlet; 10 - Air ring; 11 - Second air inlet; 12 - Bottom flow channel inlet; 13 - Bottom flow channel outlet. Specific embodiments

[0065] The following uses specific specific examples to illustrate the implementation manners of the present invention. Those skilled in the art can easily understand the other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0066] Specific embodiment one: Combine Figure 1 、 Figure 2, Figure 3-1 , Figure 3-2 , Figure 4 , Figure 5-1 , Figure 5-2 , Figure 6 , Figure 7 , Figure 8 , Figure 9 , Figure 10 , Figure 11 , Figure 12-1 , Figure 12-2 , Figure 13 , Figure 14-1 , Figure 14-2 , Figure 15-1 , Figure 15-2 , Figure 16-1 , Figure 16-2 , Figure 17-1 , Figure 17-2 , Figure 18-1 , Figure 18-2 , Figure 19-1 , Figure 19-2 , Figure 20-1 , Figure 20-2 , Figure 21-1 , Figure 21-2 , Figure 22-1 and Figure 22-2 To illustrate this embodiment, the vertical mill in this embodiment is an existing vertical mill, and its structural components include a grinding table 2, grinding rollers 3, a hopper 4, static vanes 5, and dynamic vanes 7; a housing 8 and an air ring 10. The housing 8 is vertically arranged. Inside the housing 8, a grinding table 2, grinding rollers 3, and a hopper 4 are sequentially arranged from bottom to top. The air ring 10 is coaxially arranged on top of the grinding table 2. An inlet 9 communicating with the hopper 4 is machined on the outer wall of the housing 8. Static vanes 5 are arranged at the top of the hopper 4. The dynamic vanes 7 are coaxially sleeved inside the static vanes 5. A fine powder outlet 6 is machined at the top of the air ring housing 8. A first air inlet 1 and a second air inlet 11 are respectively machined at the bottom of the housing 8. The structural form and working principle of the vertical mill are the same as those of the existing vertical mill. Among them, a bottom flow channel outlet 13 and a bottom flow channel inlet 12 are respectively formed between the top and bottom of the grinding table 2 and the housing 8. The bottom flow channel inlet 12 is a tapered wide-width opening, and the bottom flow channel outlet 13 is a narrow-width opening. The bottom flow channel outlet 13 is above the bottom flow channel inlet 12.

[0067] The method for obtaining the inlet air duct of the vertical mill in this embodiment is to determine the data collected in the existing vertical mill, establish the model of the existing vertical mill as the original model, determine the internal fluid domain of the vertical mill in the original model, and after two-dimensional topological processing of the internal fluid domain of the vertical mill, form the first set of component data. After comparing the first set of component data with the internal fluid domain of the vertical mill, when the minimum value of the main machine pressure loss is reached, the corresponding data is determined as the first set of optimized data. After the internal fluid domain of the vertical mill is processed by the volute guide, the second set of component data is formed. After comparing the second set of component data with the internal fluid domain of the vertical mill, when the maximum value is reached under the condition that the wind ring outlet and the main machine outlet wind speeds are in a uniform state, the corresponding data is determined as the second set of optimized data. Based on the first set of optimized data and the second set of optimized data, the ultimate model of the entire vertical mill is established.

[0068] In this embodiment, the original model is established by collecting the mill data. The process of using the internal fluid domain of the vertical mill in the original model is to simplify the design scheme model through the Space Claim module provided by the ANSYS workbench platform to form a simplified model, extract the internal fluid domain of the vertical mill from the simplified model, and create the internal fluid domain of the vertical mill after naming each boundary in the simplified model.

[0069] In this embodiment, after two-dimensional topological processing of the internal fluid domain of the vertical mill, the first set of component data is formed. The process of comparing the first set of component data with the internal fluid domain of the vertical mill and determining the corresponding data as the first set of optimized data when the minimum value of the main machine pressure loss is reached is to perform mesh division on the internal fluid domain of the vertical mill through Fluent meshing. After the division is completed, primary data is formed. The primary data is set with simulation operation parameters to form secondary data. The secondary data is subjected to two-dimensional topological optimization processing through the COMSOL platform to form the first set of component data. According to the theoretical standard value of the internal data of the vertical mill, the first set of component data is compared with the internal fluid domain of the vertical mill, and the data in the first set of component data corresponding to the minimum value of the main machine pressure loss is determined as the first set of optimized data.

[0070] In this embodiment, after the internal fluid domain of the vertical mill is processed by the volute guide, the second set of component data is formed. The process of comparing the second set of component data with the internal fluid domain of the vertical mill and determining the corresponding data as the second set of optimized data when the maximum value is reached under the condition that the wind ring outlet and the main machine outlet wind speeds are in a uniform state is to form the three-dimensional bottom shell 8 of the vertical mill host through Solidworks modeling. The wind ring outlet and the main machine outlet wind speed data of the three-dimensional bottom shell 8 of the vertical mill host are processed by the volute guide to form the second set of component data. In the second set of component data, the data corresponding to the maximum value when the wind ring outlet and the main machine outlet wind speeds are in a uniform state is used as the second set of optimized data.

[0071] Embodiment 2: This embodiment is a further limitation of Embodiment 1. In this embodiment, the specific process of determining the internal fluid domain of the vertical mill in the original model is the Flunet flow field analysis process of the entire vertical mill. Combining with Figure 1 As shown, first, model processing is carried out. The data of the existing vertical mill is collected and imported to establish a three-dimensional model of the vertical mill. The three-dimensional model of the vertical mill is imported into Space Claim for model simplification and flow field extraction. The model within the mill flow field is retained, and the model outside the mill flow field is deleted. Local features that have a relatively small impact on the overall structure analysis are ignored. Some transition structures are simplified to their original structural shapes. At the same time, features such as small holes, fillets, and chamfers are simplified to the original entities to avoid errors during analysis.

[0072] Combining with Figure 2 As shown, the vertical mill in this embodiment is an existing vertical mill, and its structure and working principle are the same as those of the existing vertical mill. Specifically: The second air inlet 11 is distributed at 180°. The grinding table 2 is the feeding surface for the ground particle mixture. Without considering the feeding at the feeding port 9 and the particle grinding of the grinding roller 3, the air flow enters the bottom of the main machine from the first air inlet 1 and the second air inlet 11, and after coming out from the air ring 10, it moves upward along the wall surface of the housing 8. The particles are driven upward by the air flow and are classified through the static and dynamic double rotating cages composed of the static blades 5 and the dynamic blades 7. The fine particles entering the dynamic blade 7 quickly come out from the fine powder outlet 6 under the high-speed rotation of the dynamic blade 7 to complete the collection of the finished particles. The particles that enter the static blade 5 but do not enter the dynamic blade 7 are returned to the bottom of the grinding table 2 by the ash hopper 4.

[0073] Embodiment 3: This embodiment is a further limitation of Embodiment 1 or 2. In this embodiment, the process of optimizing the first set of data is to perform mesh division on the internal fluid domain of the vertical mill through Fluent meshing. The specific process is divided into steps of mesh division, simulation condition setting, and simulation result analysis. Among them, the mesh division is carried out through Fluentmeshing. The minimum size of the surface mesh is 0.002m, the maximum quality is 0.0405m, the growth rate is 1.2, the number of layers of the gap filling unit is 2, and the maximum size of the volume mesh is 0.05m with a growth rate of 1.2. The simulation condition setting in this embodiment is as follows for the gas phase boundary conditions when the vertical mill is in an idling maintenance state and only air is passed without adding materials:

[0074] 1) Definition of the air inlet: The boundary type of the air inlet is defined as a velocity inlet;

[0075] The total inlet air volume is Q = 489600m 3 / h, and the two identical air inlets are distributed at 180°;

[0076] The single-port inlet air volume is

[0077] The inlet size of the mill A1 = 2000×1000mm 2 = 2m 2 ;

[0078] The direction is perpendicular to the plane where the air inlet is located, the air inlet pressure is 0Pa, and the density of the air entering the mill ρ = 1.225kg / m 2 ;

[0079] The hydraulic diameter formula is:

[0080]

[0081] In the above formula, A is the boundary cross-sectional area, and P is the wetted perimeter of the boundary flow domain;

[0082] Gas Reynolds number:

[0083]

[0084] Turbulence intensity: I = 0.16R e -0.125 = 0.0246975;

[0085] 2) Definition of the air outlet: The air outlet boundary type is defined as a pressure inlet, and the pressure is -6000Pa;

[0086] 3) Definition of the feed inlet 9: When no material is added and only air passes through, it is defined as a velocity inlet, and the velocity is 0;

[0087] 4) Definition of the moving vane 7 area and other rotating structures. The rotation process of the moving vane 7 of the classifier is simulated through the MRF multiple reference coordinate system model, and the rotation process of the moving vane 7 of the classifier is approximated as a steady motion. According to the right-hand rule, the rotation speed of the classifier is defined as 120r / min, and the wall surface of the moving vane 7 and the wall surfaces of other rotating structures are set to move following the adjacent grids, and their relative rotation speed is set to 0r / min, so as to realize the rotation of the moving vane 7 and the rotating shaft at the rotation speed set in the moving vane 7 area.

[0088] Table 1-1 Boundary condition settings

[0089]

[0090] Combined with Figure 3-1 、 Figure 3-2 and Figure 4As shown in the figure, the simulation result analysis in this embodiment is that the air flow enters the vertical mill from the air inlet. When passing through the air ring 10, due to the sudden decrease in the cross-sectional area of the air ring 10, the air flow velocity changes suddenly at the air ring 10, the wind speed increases sharply, and the air flow moves upward along the main machine barrel wall from the air ring outlet. Due to the obstruction of the grinding roller 3, the direction of the air flow changes. When the air flow reaches the classifier, due to the obstruction of the static vane 5, the air flow first flows around the blades in all directions, and a part of it moves upward into the moving vane 7. Through the rotation of the moving vane 7, the air flow velocity inside the classifier is rapidly increased, and the high-speed air flow quickly exits from the vertical mill outlet along the wall surface of the vertical mill housing 8; another part of the air flow expands downward along the hopper 4 through the internal flow field and returns to the bottom of the grinding table 2.

[0091] Through Figure 5-1 and Figure 5-2 it can be known that: the overall wind speed at the air ring outlet of the vertical mill is about 42.4 - 106 m / s, and the wind speed shows an obviously uneven state, manifested as areas with excessive local speed and areas with a speed of 0. Excessive local speed will cause an excessive overall speed gradient, resulting in flow field disturbance, and areas with a speed of 0 will form unnecessary vortices, increasing the main machine pressure loss.

[0092] Specific Embodiment 4: This embodiment is a further limitation of Specific Embodiment 1, 2 or 3. In this embodiment, the optimization of the air inlet duct structure of the vertical mill and the Fluent flow field analysis process are as follows: Through the simulation analysis of the entire vertical mill by Fluent, it can be known that there are problems such as uneven wind speed at the air ring outlet of the vertical mill main machine and excessive pressure loss. With the goal of improving the uneven wind speed at the air ring outlet of the vertical mill and reducing the main machine pressure loss of the vertical mill, the structure of the vertical mill main machine is optimized.

[0093] The sources of the main machine pressure loss of the vertical mill are mainly concentrated in the bottom housing 8 of the vertical mill, the air ring 10, the grinding roller 3, the grinding table 2 and other structures. Since the particle grinding in the grinding roller 3 and the grinding table 2 is not considered, only the structure of the main machine housing 8 of the vertical mill and the air ring structure are optimized.

[0094] Specific Embodiment 5: This embodiment is a further limitation of Specific Embodiment 1, 2, 3 or 4. Combining Figure 6 As shown in the figure, in this embodiment, after the internal fluid domain of the vertical mill is processed by two-dimensional topology, the two-dimensional topology in the first set of data is the two-dimensional topology optimization of the cross-section of the vertical mill housing 8. Specifically, the bottom of the vertical mill housing 8 is simplified into a flow channel structure form arranged around the periphery of a frustum structure with a depression at the top. With the goal of minimizing the pressure loss at the bottom flow channel outlet 13 and the bottom flow channel inlet 12, the two-dimensional topology optimization of the cross-section of the flow channel in this area is carried out by COMSOL.

[0095] Specific Embodiment 6: This embodiment is a further limitation of Specific Embodiment 1, 2, 3, 4 or 5. Combining Figure 7As shown in Table 2-1, the COMSOL topology optimization process and the core operation settings therein are presented. The setting modules are divided into 1 to 8 in the order of operations in COMSOL.

[0096] In this embodiment, the topology optimization is set to benefit from the high efficiency of COMSOL in solving partial differential equations and the high efficiency of automatically solving the sensitivity of any objective function. Based on the COMSOL platform, a simplified boundary condition structure topology optimization design is realized. Among them, setting global parameters and establishing a calculation model involves naming the density and dynamic viscosity of the material as rho_liquid and mu_liquid, and assigning values of 1000 [kg / m^3] and 0.001 [Pa*s], defining the volume coefficient alpha_max, and assigning a value of 1e5 [Pa*s / m^2], defining the geometric dimensions t1, t2 and the velocity v1, and assigning values of 61 [mm], 640 [mm], 1 [m / s], which is convenient for subsequent reference in settings. Combining Figure 8 as shown, a two-dimensional geometric model is constructed.

[0097] Table 2-1 Global Parameters

[0098]

[0099] In this embodiment, topology optimization variables are added. The design domain is set as the density model 1 (dtopo1), and the non-design domain is set as the empty material area.

[0100]

[0101] Among them, a material unit with variable body force is defined to fill the design domain to control the changes of the entity and the flow channel. ρ is the material density, K is the thermal conductivity, is the gradient operator, u is the velocity, F is the actual body force, and the expression is as follows:

[0102] F = θ c × alpha_max

[0103] where F is the actual body force, θ c represents the material phase in the design domain, controlling the changes of the entity and the flow channel. The variable θ c takes values in the interval (0, 1), taking 0 represents the entity, and alpha_max is the maximum volume coefficient.

[0104] The interpolation model is a user-defined interpolation function. In topology optimization, this interpolation model is a non-linear interpolation model with a penalty effect on intermediate variables, and its expression is:

[0105] The Helmholtz filter is used to filter the design variables, and its expression is:

[0106]

[0107] Among them, θ f is the filtered material volume factor, and θ c is the control material volume factor, and R min is the filtration radius 6.1 [mm] * 3.

[0108] Selecting to eliminate the intermediate density based on the hyperbolic tangent function projection can obtain a relatively clear topological image, and its expression is:

[0109]

[0110] Among them, β is the projection slope, and θ β is the projection point.

[0111] Its detailed settings are shown in Table 2-2.

[0112] Table 2-2 Density Model

[0113]

[0114] In this embodiment, the process of defining variables is to set three non-local couplings, namely the average value of the air inlet aveop1 and the average value of the outlet aveop2, integrate the design domain intop1, and then define three variables as shown in Table 2-3.

[0115] Table 2-3 Defined Variables

[0116]

[0117] In this embodiment, the process of defining the objective function is: defining the pressure drop between the air inlet and the outlet as PP, and the expression is aveop1(p) - aveop2(p). The constraint condition is that the average volume factor of the material is named s11, and the expression is intop1(dtopo1.theta) * t1, with an upper limit of 3E-2 [m^3] and a lower limit of 1E-6 [m^3].

[0118] In this embodiment, the material properties are defined as shown in Table 2-4 below

[0119] Table 2-4 Fluid Properties

[0120]

[0121] Combined with Figure 7 As shown, in this embodiment, the process of setting the boundary conditions is that the model is laminar steady state, the air inlet is set as a velocity inlet, the direction is the normal inflow velocity, the velocity magnitude is v1, the outlet is a pressure outlet, the pressure magnitude is defaulted to 0, and a body force is added to the design domain.

[0122] Combined withFigure 9 As shown, the specific process of mesh generation in this embodiment is as follows: for two-dimensional problems, free quadrilateral meshing can be used. The maximum element size is 6.1 mm, the minimum element size is 0.489 mm, the curvature factor is 0.3, the maximum element growth rate is 1.3. After mesh generation, the average element quality is 0.9994, meeting the requirements.

[0123] The process of topology optimization calculation in this embodiment is to add a topology optimization module to the study, select the IPOP solver, optimization tolerance: 0.001, number of iteration steps: 100, retain solutions: the last N, number of solutions to be saved: 1000, and the remaining parameters are default as shown in Table 2-5.

[0124] Table 2-5 Topology Optimization Calculation Method

[0125]

[0126] Among them, the IPOP algorithm is used in the optimization solver to optimize and solve the topology optimization mathematical model. The condition for topology optimization convergence is:

[0127] max|θ pi -θ pi-1 |≤E

[0128] where, θ pi is the value of the design variable in the current iteration process, and θ pi-1 is the value of the design variable in the previous iteration process. E is the optimization tolerance.

[0129] The objective function of topology optimization is to minimize the pressure loss in the design domain, and its expression is:

[0130] PP = aveop1(p) - aveop2(p);

[0131] where PP is the average pressure loss in the calculation domain, aveop1(p) is the inlet pressure, and aveop2(p) is the outlet pressure;

[0132] The constraint condition of topology optimization is the flow channel volume interval, and its expression is:

[0133] s11 = intop1(dtopo1.theta) * t1 = ∫ Ω (dtopo1.theta) * t1d Ω ;

[0134] s11 min ≤∫ Ω (dtopo1.theta) * t1d Ω ≤s11 max ;

[0135] where Ω is the design domain, s11 min is the lower bound of the average volume factor, s11 max is the upper bound of the average volume factor;

[0136] The mathematical model for the topological optimization of the flow channel is expressed as:

[0137] Find: θ pi (i = 1, 2,..., n), θ c = [0, 1]

[0138] Minimize: PP = aveop1(p) - aveop2(p)

[0139] Subject to: θ c = [0, 1]

[0140]

[0141] s11 min ≤ ∫ Ω (dtopo1.theta) * t1d Ω ≤ s11 max

[0142] where, θ c is the design variable for topological optimization, i is the subscript of each design variable, q is the penalty coefficient in the difference model, s11 min is the lower bound of the average volume factor, s11 max is the upper bound of the average volume factor.

[0143] Combined with Figure 10 As shown, in this embodiment, the result of topological optimization is the target probe calculation for the pressure drop at the outlet of the air inlet. Through topological optimization, the target probe result of the pressure drop at the outlet of the air inlet is shown in Table 2 - 6. When the optimization solution = 76, the pressure drop reaches 1.0102×10 5 Pa, and finally the two - dimensional cross - section topological optimization result of the vertical mill is obtained.

[0144] Table 2 - 6 Target Probe of the Pressure Drop at the Outlet of the Air Inlet

[0145]

[0146]

[0147] Combined with Figure 11As shown, in this embodiment, three-dimensional modeling of the topology optimization result is to obtain the distribution of materials in the channel after optimization. It is necessary to extract the distribution of materials in the channel. After extracting all the 2D structure graphics in the finally optimized mph file and saving them in the form of a dxf file, some sharp corners in the graphics are processed using CAD software.

[0148] Import the processed graphics into Space Claim software for modeling, combined with Figure 12-1 and Figure 12-2 As shown, before and after topology optimization, with the original air ring arrangement, the bottom model of the vertical mill housing 8 is assembled into the whole vertical mill, and Fluent simulation analysis is carried out.

[0149] Through Figure 14-1 and Figure 14-2 It can be seen that after topology optimization, the overall average velocity and Y-direction velocity at the air ring outlet increase significantly, but the overall average velocity and Y-direction velocity at the air ring outlet are still uneven. As shown in Table 2-9, through Fluent calculation, it can be obtained that before and after topology optimization, the Y-direction average wind speeds at the air ring outlet are 24.49 m / s and 33.77 m / s respectively. After topology optimization, the Y-direction average wind speed at the air ring outlet increases by 9.28 m / s compared with that before topology optimization. As shown in Table 2-7, before and after topology optimization, the main machine pressure losses are 13169.44 Pa and 7429.87 Pa respectively. After topology optimization, the main machine pressure loss decreases by 5739.57 Pa compared with that before topology optimization; the pressure losses at the air ring outlet are 10179.86 Pa and 6723.15 Pa respectively. After topology optimization, the pressure loss at the air ring outlet decreases by 3456.71 Pa compared with that before topology optimization.

[0150] Table 2-7 Changes in Y-direction average velocity and pressure loss of the air ring

[0151]

[0152] According to the energy conservation equation, the internal flow field of the vertical mill main machine belongs to incompressible flow. Then, the change in pressure loss inside the flow field is directly related to the energy input from the outside, and the magnitude of the pressure loss directly affects the energy consumption in the classifier. For the steady flow equation with energy input, it can be described as:

[0153]

[0154] In the formula, W shaft is the shaft work per unit mass input to the fluid; the ratio of p to ρ is the flow energy per unit mass; gy is the potential energy per unit mass of the fluid; e is the internal energy; q in is the heat per unit mass transferred to the fluid; in this article, the internal energy and the heat transferred to the fluid are not considered due to the collision between molecules, (e2 - e1 - q in)Neglected; P is the absolute pressure, Pa; ρ is the density, kg / m 3 ; v is the velocity, m / s; g is the acceleration due to gravity, m / s 2 ; y is the spatial position, m.

[0155] After arranging the above formula, the change law of the flow energy of the gas at the inlet and outlet of the main mill is as follows:

[0156]

[0157] In the above formula, the difference between P2 and P1 is the pressure loss of the main vertical mill.

[0158] Then, the energy loss in the design scheme can be converted from the shaft work per unit mass, and the energy consumption difference between the design schemes of each main vertical mill and the original scheme can be evaluated. The energy loss can be expressed by the following formula:

[0159]

[0160] In the above formula, W elec is the energy loss, kWh; V0 is the continuous air inflow at the air inlet, m 3 / h.

[0161] Table 2-8 Statistics of Energy Loss of the Main Vertical Mill

[0162]

[0163] From the comparison data in Table 2-8, it can be seen that the energy consumption of the main machine before and after topology optimization is 1718.00 kWh and 945.31 kWh respectively, and the energy consumption reduction ratio after topology optimization is 44.98% compared with that before topology optimization.

[0164] Through Figure 16-1 and 16-2 it can be known that the overall law of the velocity trace of the whole vertical mill after topology optimization is basically the same as that before topology optimization. The velocity streamline at the bottom shell 8 of the main vertical mill after topology optimization is significantly improved compared with that before topology optimization. There is a local area without velocity trace at the bottom shell 8 of the main vertical mill before topology optimization, and the local area without velocity trace disappears after topology optimization.

[0165] Specific Embodiment Seven: This embodiment is a further limitation of Specific Embodiments One, Two, Three, Four, Five or Six. In this embodiment, the volute guiding process of the bottom shell 8 is through Figures 5-1 to 15-2It can be seen that there is a problem of uneven air velocity at the outlet of the air ring of the vertical mill main machine. In response to the uneven air velocity at the outlet of the air ring of the vertical mill main machine, a volute guide design is carried out on the bottom shell 8 of the vertical mill main machine, and the volute size is adjusted: the circular shell 8 with a radius of R = 3315 mm at the bottom of the vertical mill main machine is subjected to a volute guide design with a gradual change from R1 = 3315 mm to R2 = 3215 mm. At the same time, the air ring blades at the 1 / 4 position with relatively uniform average air velocity at the outlet of the air ring are symmetrically processed adjacent to each other to obtain a new air ring structure. The volute structure and the new air ring are combined to form Plan 1, and the original model at the bottom of the vertical mill shell 8 is called the original plan.

[0166] In this embodiment, Fluent simulation analysis:

[0167] The models of Plan 1 are combined into a complete vertical mill, and Fluent simulation analysis is carried out, and a comparative analysis is made with the Fluent simulation results of the complete vertical mill of the original plan.

[0168] Table 2-9 Changes in the average Y-direction air velocity and pressure loss of the air ring

[0169]

[0170]

[0171] It can be obtained through Fluent calculation that the average Y-direction air velocities at the outlet of the air ring of the original plan and Plan 1 are 24.49 m / s and 24.45 m / s respectively. Although the average Y-direction air velocity of Plan 1 is 0.04 m / s lower than that of the original plan, the overall average air velocity and Y-direction air velocity at the outlet of the air ring of Plan 1 are more uniform; as can be seen from Table 2-9, the main machine pressure losses of the original plan and Plan 1 are 13169.44 Pa and 12841.18 Pa respectively, and the main machine pressure loss of Plan 1 is 328.26 Pa lower than that of the original plan; the pressure losses at the outlet of the air ring are 10179.86 Pa and 9785.97 Pa respectively, and the pressure loss at the outlet of the air ring of Plan 1 is 393.89 Pa lower than that of the original plan.

[0172] Table 2-10 Statistics of the energy loss of the vertical mill main machine

[0173]

[0174] From the comparison data in Table 2-10, it can be seen that the main machine energy consumptions of Plan 1 and the original plan are 1674.85 kWh and 1718.00 kWh respectively, and the energy consumption reduction ratio of Plan 1 compared with the original plan is 2.51%.

[0175] The overall law of the velocity trace of Solution 1 changes significantly compared with the original solution. Although there are still local areas without velocity traces at the bottom shell 8 of the main mill, in Solution 1, the air flow directly moves upward along the wall of the shell 8 after coming out of the air ring, while the air flow in the original solution has an obvious swirling trend during the upward movement, resulting in an increase in the circulating load of the vertical mill and an increase in energy consumption.

[0176] In this embodiment, the processing process of the volute guidance of the bottom shell 8 based on topology optimization is divided into the following parts:

[0177] Combined Figure 19-1 and Figure 19-2 As shown, in the first structural design part, specifically, the structure of the grinding table 2 after topology optimization and the volute-shaped shell 8 are combined to form Solution 2.

[0178] The second part is the Fluent simulation analysis. The model of Solution 2 is combined into the whole vertical mill, and the Fluent simulation analysis is carried out, and a comparative analysis is made with the Fluent simulation results of the whole vertical mill of the original solution.

[0179] Table 2-11 Changes in the average velocity and pressure loss in the Y direction of the air ring

[0180]

[0181]

[0182] Through Figure 20-1 、 Figure 20-2 、 Figure 21-1 and Figure 21-2 It can be seen that the overall average velocity and the comparison of the velocity in the Y direction at the air ring outlet of the original solution and Solution 2 change significantly. Through FLUENT calculation, it can be obtained that the average wind speeds in the Y direction at the air ring outlet of the original solution and Solution 1 are 6.66m / s and 6.19 / s respectively, and the average wind speeds in the Y direction at the main machine outlet are 3.83m / s and 3.80m / s respectively. Although the average wind speed in the Y direction of Solution 2 is slightly lower than that of the original solution, it can be ignored, and the overall average velocity and the velocity in the Y direction at the air ring outlet of Solution 2 are more uniform; as can be seen from Table 2-11, the main machine pressure losses of the original solution and Solution 2 are 13169.44Pa and 10812.59Pa respectively, and the main machine pressure loss of Solution 2 is reduced by 2456.85Pa compared with the original solution; the pressure losses at the air ring outlet are 10179.86Pa and 7718.62Pa respectively, and the pressure loss at the air ring outlet of Solution 2 is reduced by 2461.24Pa compared with the original solution.

[0183] Table 2-12 Statistics of the energy loss of the vertical mill main machine

[0184]

[0185] From the comparison data in Table 2-12, it can be seen that the main engine energy consumption of the second solution and the original solution are 1395.37 kWh and 1718.00 kWh respectively. The energy consumption reduction ratio of the second solution compared to the original solution is 18.78%.

[0186] The overall law of the velocity trace of the first solution changes significantly compared to the original solution. In the original solution, there is a local area in the bottom shell 8 of the vertical mill main engine without velocity traces. Thanks to the topologically optimized structure of the second solution, the local area without velocity traces disappears. However, in the first solution, the air flow directly moves upward along the wall surface of the shell 8 after coming out of the air ring 10, while the air flow in the original solution has an obvious swirling trend during the upward movement, resulting in an increase in the circulating load of the vertical mill and an increase in energy consumption. Although the overall law of the flow field traces of the whole vertical mill in the first solution and the second solution is basically the same, the main engine pressure loss of the second solution is 2028.59 Pa lower than that of the first solution, and the energy consumption reduction ratio of the second solution compared to the first solution is 16.69%. Therefore, the second solution is the optimal solution.

[0187] In this embodiment, the particle collection process includes condition setting. The condition setting is mainly in the simulation study of the vertical mill flow field. The vertical mill is mainly used for grinding steel slag with a density of 3.1 - 3.6 g / cm 3 For the convenience of calculation, we take a density of 3.5 g / cm 3 . The numerical simulation calculation uses the DPM discrete phase model. The inside of the vertical mill is mainly composed of two phases. The gas phase is the untreated air directly introduced during the production process of the vertical mill, and the discrete phase is the raw material particle steel slag.

[0188] According to the rotational speed of the grinding table 2, it is assumed that the particles after grinding are injected into the vertical mill flow field perpendicular to the bottom surface of the grinding table 2 with an initial velocity of zero. The DPM discrete phase particle distribution adopts the Rosin-Rammler distribution, and Y d is defined as the mass fraction of particles larger than the specified particle size d. According to the Rosin-Rammler distribution function, an exponential relationship is assumed between the particle size d and Y d :

[0189]

[0190] where Y d is the mass fraction of particles larger than the specified particle size d, d m is the average particle size, and n is the distribution coefficient.

[0191] The particles of 200 - 500 mesh are converted into 30 - 75 μm, and the Rosin-Rammler distribution design is carried out. Through the above calculation, the actual material sampling is converted into the simulated calculation particle size distribution. The minimum particle size is 30 μm, the maximum particle size is 75 μm, and the average particle size d m= 56.303571 μm, distribution coefficient n = 6.233955, the number of diameters is set to 4, and the mass flow rate of the DPM discrete phase particles is 1 kg / s (360 t / h).

[0192] In the Fluent simulation analysis of this embodiment, the original scheme and Scheme 2 are subjected to the Fluent feeding material simulation analysis. Through Figure 22-1 and Figure 22-2 It can be seen that due to the structure after topological optimization and the volute guiding design in Scheme 2, the particles quickly reach the classifier from the bottom of the grinding table 2 and are quickly collected by the fine powder outlet 6 under the classification of the classifier. However, the particles in the original scheme have an obvious swirling trend during the rising process, resulting in an increase in the circulating load of the vertical mill and an increase in energy consumption.

[0193]

[0194] As can be seen from Table 3-1, although the change in the particle collection efficiency of Scheme 2 for particles of 30 - 75 μm compared with the original scheme is not obvious, theoretically, the reduction in the main engine energy consumption of Scheme 2 increases the air flow velocity, increases the kinetic energy obtained by the particles, and enables the particles to rise from the bottom of the grinding table 2 to the classifier faster to complete particle classification.

[0195] Table 3-2 Particle collection of Scheme 2

[0196]

[0197]

[0198] Theoretically, compared with the original scheme, the energy consumption reduction ratio of Scheme 2 is 18.78%. The reduction in energy consumption indicates that: under the condition of stable particle collection efficiency, a smaller air inlet wind speed is required. The collection efficiency range of the vertical mill is: 200 mesh to 500 mesh. Taking the 200-mesh particle collection efficiency as the research target, the air inlet wind speed is studied.

[0199] As can be seen from Table 3-2, by setting three groups of wind speeds: 30 m / s, 20 m / s, and 15 m / s, the 200-mesh particle collection efficiency decreases from 99.85% to 64.6%. It can be seen that there is a wind speed of 15 m / s ≤ v ≤ 20 m / s, which makes the 200-mesh collection efficiency stable above 90%. Interpolating 18 m / s within the wind speed range of 15 m / s to 20 m / s, the 200-mesh particle collection efficiency is 94.37%. Therefore, 18 m / s is roughly defined as the minimum speed at which the 200-mesh collection efficiency in Scheme 2 is stable above 90%.

[0200] Table 3-3 Statistics of the main engine energy loss of the vertical mill

[0201]

[0202] From the comparison data in Table 3-3, it can be seen that by reducing the inlet air velocity, the main machine energy consumption of Scheme II and the original scheme are 799.77 kWh and 1718.00 kWh respectively. The energy consumption reduction ratio of Scheme II compared to the original scheme is 53.45%.

[0203] Scheme II obtained through the topological optimization and the volute-guided inlet air duct design of the vertical mill reduces the main machine pressure loss by 2456.85 Pa compared to the original scheme, and the energy consumption reduction ratio compared to the original scheme is 18.78%. Through topological optimization and volute-guided design, the main machine pressure loss and energy consumption of the vertical mill are significantly reduced; at the same time, the uniformity of the air velocity at the wind ring outlet is improved, the flow field disturbance of the main machine of the vertical mill is reduced, the unnecessary circulating load is reduced, and the particle collection efficiency is significantly improved.

[0204] Specific Embodiment VIII: Combining Figures 1 to 22-2 To illustrate this embodiment, the evaluation method for the inlet air duct of the vertical mill based on topological optimization and volute guidance in this embodiment is as follows: After determining the internal fluid domain of the vertical mill in the original model, the internal fluid domain of the vertical mill is subjected to two-dimensional topological processing to form the first set of component data. After comparing the first set of component data with the internal fluid domain of the vertical mill, the corresponding data at the lowest value of the main machine pressure loss is determined as the first set of optimized data. The internal fluid domain of the vertical mill is subjected to volute guidance processing to form the second set of component data. After comparing the second set of component data with the internal fluid domain of the vertical mill, the corresponding data at the highest value when the air velocity at the wind ring outlet and the main machine outlet is in a uniform state is determined as the second set of optimized data. Based on the first set of optimized data and the second set of optimized data, the ultimate model of the entire vertical mill is established, and a hierarchical evaluation process is carried out on the ultimate model using the steady-state solution method.

[0205] In this embodiment, the ultimate model is the DPM model, and the process of carrying out a hierarchical evaluation of the ultimate model using the steady-state solution method is a process of analyzing the particle collection efficiency and corresponding analysis and rating of the particle upward movement trajectory based on the DPM model.

[0206] The process of carrying out a hierarchical evaluation of the ultimate model is as follows: Under the same vertical mill operating parameters, energy consumption, the uniformity of the air velocity at the wind ring outlet, and the particle collection efficiency are determined as three indicators. The energy consumption, the uniformity of the air velocity at the wind ring outlet, and the particle collection efficiency of the ultimate model and the original model are respectively compared. When the energy consumption reduction ratio of the ultimate model compared to the original model is equal to or lower than 18.78%, the uniformity of the air velocity cloud map at the wind ring outlet of the ultimate model compared to the original model is improved, and the 200-mesh particle collection efficiency of the ultimate model compared to the original model reaches over 90%, it indicates that under the same vertical mill operating parameters, the ultimate model obtained by optimizing the structural parameters of the vertical mill is superior to the original model. The content not mentioned in this embodiment is the same as that in Specific Embodiments I, II, III, IV, V, VI, or VII.

[0207] Specific Embodiment IX: This embodiment is a further limitation of Specific Embodiment VIII. In this embodiment, when the structural parameters of the vertical mill are the same and only the single operating parameter of the air inlet velocity of the vertical mill is different, with the collection efficiency of 200-mesh particles reaching over 90% as the evaluation criterion, when the air inlet velocity of the ultimate model decreases from 34 m / s to 18 m / s, the collection efficiency of 200-mesh particles can still reach over 90%. At this time, the energy consumption reduction ratio of the ultimate model compared to the original model is equal to or lower than 53.45%, indicating that the ultimate model is superior to the original model.

Claims

1. A method for obtaining the air inlet duct of a vertical mill based on topology optimization and volute guidance, characterized in that: The method for obtaining the air inlet duct of the vertical mill is as follows: After determining the internal fluid domain of the vertical mill in the original model, the internal fluid domain of the vertical mill is subjected to two-dimensional topology processing to form the first set of component data. After comparing the first set of component data with the internal fluid domain of the vertical mill, the corresponding data at the lowest main machine pressure loss is determined as the first set of optimized data. The internal fluid domain of the vertical mill is subjected to volute guiding processing to form the second set of component data. After comparing the second set of component data with the internal fluid domain of the vertical mill, the corresponding data at the highest value when the wind ring outlet and the main machine outlet wind speeds are in a uniform state is determined as the second set of optimized data. Based on the first set of optimized data and the second set of optimized data, the ultimate model of the entire vertical mill is established.

2. The method for obtaining the air inlet duct of a vertical mill based on topology optimization and volute guidance according to claim 1, wherein: The original model is established by collecting mill data. The process of using the internal fluid domain of the vertical mill in the original model is to simplify the design scheme model through the Space Claim module provided by the ANSYS workbench platform to form a simplified model. The internal fluid domain of the vertical mill is extracted from the simplified model, and after naming each boundary in the simplified model, the internal fluid domain of the vertical mill is created.

3. A method for obtaining the air inlet duct of a vertical mill based on topology optimization and volute guidance according to claim 1, characterized in that: The process of forming the first set of component data after subjecting the internal fluid domain of the vertical mill to two-dimensional topology processing, and determining the corresponding data as the first set of optimized data when the main machine pressure loss is at the lowest value after comparing the first set of component data with the internal fluid domain of the vertical mill is as follows: The internal fluid domain of the vertical mill is meshed by Fluent meshing. After the meshing is completed, primary data is formed. The primary data is set with simulation operation parameters to form secondary data. The secondary data is subjected to two-dimensional topology optimization processing through the COMSOL platform to form the first set of component data. According to the theoretical standard value of the internal data of the vertical mill, the first set of component data is compared with the internal fluid domain of the vertical mill, and the data in the first set of component data corresponding to the lowest main machine pressure loss is determined as the first set of optimized data.

4. A method for obtaining the air inlet duct of a vertical mill based on topology optimization and volute guidance according to claim 3, characterized in that: The calculation process of forming the first set of component data after subjecting the internal fluid domain of the vertical mill to two-dimensional topology processing is to optimize and solve the topology optimization mathematical model using the IPOP algorithm in the optimization solver. The conditions for topology optimization convergence are: max|θ pi -θ pi-1 |≤E where, θ pi is the value of the design variable in the current iteration process, and θ pi-1 is the value of the design variable in the previous iteration process; E is the optimization tolerance; The objective function of topology optimization is to minimize the pressure loss in the design domain, and its expression is: PP = aveop1(p) - aveop2(p) where PP is the average pressure loss in the domain, aveop1(p) is the inlet pressure, and aveop2(p) is the outlet pressure; The constraint condition of topology optimization is the flow channel volume interval, and its expression is: s11 = intop1(dtopo1.theta) * t1 = ∫ Ω (dtopo1.theta) * t1d Ω s11 min ≤∫Ω(dtopo1.theta)*t1d Ω ≤s11 max where Ω is the design domain, and s11 min is the lower bound of the average volume factor, and s11 max is the upper bound of the average volume factor; The flow channel topology optimization mathematical model, its expression is: Find: θ pi (i = 1, 2,..., n), θ c = [0, 1] Minimize: PP = aveop1(p) - aveop2(p) Subject to: θ c = [0, 1] s11 min ≤∫ Ω (dtopo1.theta)*t1d Ω ≤s11 max Among them, θ c is the design variable of topology optimization, i is the subscript of each design variable, q is the penalty coefficient in the difference model, and s11 min is the lower bound of the average volume factor, and s11 max is the upper bound of the average volume factor; the topology optimization result is the target probe calculation for the pressure drop at the outlet of the air inlet. Through topology optimization, the target probe result of the pressure drop at the outlet of the air inlet is obtained, the lowest value of the main machine pressure loss corresponding to the optimized solution is obtained, and finally the two-dimensional cross-section topology optimization result of the vertical mill is obtained.

5. A method for obtaining the air inlet duct of a vertical mill based on topology optimization and volute guidance according to claim 1, 2, 3 or 4, characterized in that: The process of forming the second set of component data by guiding and processing the internal fluid domain of the vertical mill through the volute, and determining the corresponding data as the second set of optimized data when the wind ring outlet and the main machine outlet wind speeds are at the highest value in the uniform state after comparing the second set of component data with the internal fluid domain of the vertical mill is to form a three-dimensional bottom shell of the vertical mill main machine through Solidworks modeling. The wind ring outlet and the main machine outlet wind speed data of the bottom shell of the vertical mill main machine are processed through the volute to form the second set of component data. In the second set of component data, the corresponding data when the wind ring outlet and the main machine outlet wind speeds are at the highest value in the uniform state is used as the second set of optimized data.

6. A method for evaluating the air inlet duct of a vertical mill based on topology optimization and volute guidance, characterized in that: The evaluation method for the air inlet duct of the vertical mill is as follows: After determining the internal fluid domain of the vertical mill in the original model, the first set of component data is formed by performing two-dimensional topological processing on the internal fluid domain of the vertical mill. After comparing the first set of component data with the internal fluid domain of the vertical mill, the corresponding data is determined as the first set of optimized data when the main machine pressure loss is at the lowest value. The second set of component data is formed by guiding and processing the internal fluid domain of the vertical mill through the volute. After comparing the second set of component data with the internal fluid domain of the vertical mill, the corresponding data is determined as the second set of optimized data when the wind ring outlet and the main machine outlet wind speeds are at the highest value in the uniform state. The ultimate model of the entire vertical mill is established based on the first set of optimized data and the second set of optimized data, and a hierarchical evaluation process is carried out on the ultimate model using the steady-state solution method.

7. The evaluation method for the air inlet duct of a vertical mill based on topology optimization and volute guidance according to claim 6, characterized in that: The ultimate model is the DPM model. The process of carrying out a hierarchical evaluation of the ultimate model using the steady-state solution method is a process of analyzing the collection efficiency of particles and corresponding analysis and rating of the particle upward movement trajectory based on the DPM model. The process of carrying out a hierarchical evaluation of the ultimate model is to determine energy consumption, wind ring outlet wind speed uniformity, and particle collection efficiency as three indicators under the same vertical mill operating parameters, and compare the three data of energy consumption, wind ring outlet wind speed uniformity, and particle collection efficiency of the ultimate model and the original model respectively. When the energy consumption reduction ratio of the ultimate model compared to the original model is equal to or lower than 18.78%, the uniformity of the wind speed cloud map at the wind ring outlet of the ultimate model compared to the original model is improved, and the 200-mesh particle collection efficiency of the ultimate model compared to the original model reaches over 90%, it indicates that under the same vertical mill operating parameters, the ultimate model obtained by optimizing the vertical mill structure parameters is superior to the original model.

8. A method for evaluating the air inlet duct of a vertical mill based on topology optimization and volute guidance according to claim 6 or 7, characterized in that: Under the condition that the vertical mill structure parameters are the same and the single operating parameter of the air inlet speed of the vertical mill inlet is different, with the 200-mesh particle collection efficiency reaching over 90% as the evaluation criterion, when the air inlet speed of the ultimate model decreases from 34 m / s to 18 m / s, the 200-mesh particle collection efficiency can still reach over 90%. At this time, the energy consumption reduction ratio of the ultimate model compared to the original model is lower than 53.45%, indicating that the ultimate model is superior to the original model.

Images