CFD-based coal mill primary air inlet guide plate structure optimization method

Abstract

The invention discloses a CFD (computational fluid dynamics)-based coal mill primary air inlet guide plate structure optimization method which comprises the following steps: drawing five concentric circles of which the diameters are regularly and progressively decreased within the radius in the inner wall of a primary air chamber of a coal mill; the intersection points of the five circles and the auxiliary lines extend to the primary air port along the tangent line, so that the primary air guide plate is positioned, and the angle deflection arrangement is positioned; performing air chamber three-dimensional modeling according to the design drawing of the primary air guide plate and the traditional design drawing without the guide plate to form two groups of models for comparison; the flow guide plate structure has a better flow dividing and guiding effect on the primary air, and the primary air can enter the primary air chamber more orderly and evenly through the flow guide plate structure. The airflow velocity distribution of each nozzle of the model additionally provided with the rotational flow guide plate is more uniform than that of an element model, the higher airflow velocity means that the coal mill has higher pulverized coal conveying capacity, and meanwhile, the more uniform airflow distribution can effectively reduce the situation that each air ring blade and internal parts of the coal mill are abraded inconsistently.

Description

Technical Field

[0001] The invention relates to coal mill technology, and in particular to a CFD-based method for optimizing the structure of a primary air inlet guide plate of a coal mill. Background Art

[0002] At present, coal mill is a machine that breaks coal blocks and grinds them into coal powder. It is an important auxiliary equipment for coal powder furnace. There are vertical mills, high-pressure suspension roller mills, medium-speed micro-powder mills, super-pressure trapezoidal mills, Raymond mills and other models.

[0003] The patent document with application number "CN201811424712.0" discloses a method for measuring the inlet primary air volume of a medium-speed coal mill, including: S1: collecting the temperature th and air volume Bh of the inlet hot primary air at the inlet hot primary air duct, collecting the temperature tc of the inlet cold primary air at the inlet cold primary air duct, and collecting the temperature te of the inlet mixed primary air at the inlet mixed primary air duct; S2: calculating the air volume Be of the inlet mixed primary air at the inlet mixed primary air duct according to the principle of thermal balance. The present invention can avoid the direct measurement of the primary air volume at the position with poor flow field distribution uniformity, and infer it through the measurement results of other positions with relatively good measurement effects, which significantly improves the measurement accuracy of the inlet primary air volume of the coal mill, and helps the operation personnel to adjust the operation.

[0004] The patent document with application number "CN201720909758.6" discloses a coal mill inlet air volume sampling device, including a front tube, a back tube is fixedly connected to the side wall of the front tube, one end of the front tube and the back tube are inserted into the air duct, and a cleaning component for cleaning dust accumulated inside the front tube is arranged inside the front tube, and speed measuring parts are installed inside the front tube and the back tube. A guiding slope is provided on the side of one end of the front tube located in the air duct away from the back tube. The utility model has the following advantages and effects: This scheme utilizes a new mechanical structure and has the effect of more accurately measuring the air volume at the air inlet.

[0005] The above patent document, combined with the prior art, reveals that the existing CFD-based coal mill primary air inlet guide plate structure optimization method has the following defects:

[0006] 1. The primary hot air of the coal mill is introduced into the wind chamber tangentially through the rectangular opening on the lower side of the coal mill body, and the rectangular opening is mainly limited by factors such as the height of the equipment structure;

[0007] 2. The primary hot air of the coal mill is generally blown into the primary air chamber in a clockwise direction when viewed from above; in order to achieve tangential blowing of the wind as much as possible, several guide plates are generally set at the primary air outlet to ensure uniform introduction of the primary air and uniform distribution of the airflow inside the coal mill. However, the current guide plates at the primary air outlet are usually single plates set on the center line of the primary air or multi-plate styles arranged in parallel. Although the above styles can divert the primary air and reduce the resistance of the primary air entering the air chamber, the kinetic energy loss of the primary air is still large. Therefore, a primary air inlet guide plate structure with a more prominent diversion and drainage effect on the primary air is needed. Summary of the invention

[0008] In order to overcome the deficiencies of the prior art, the present invention provides a CFD-based method for optimizing the structure of the guide plate at the primary air inlet of a coal mill, which solves the problem that the kinetic energy loss of the primary air at the guide plate is still relatively large.

[0009] The first aspect of the present invention is to provide a method for optimizing the structure of a primary air inlet guide plate of a coal mill based on CFD, comprising:

[0010] Step S10: in the inner wall of the primary air chamber of the coal mill, five concentric circles with decreasing diameters are made along the radius, and the diameters are circle 1 to circle 5 from small to large;

[0011] Step S20: draw an auxiliary line perpendicular to the center line of the primary air inlet, draw a tangent line through the intersection of circles 1 to 5 and the auxiliary line to the primary air outlet and extend to the primary air outlet, locate the positioning and angle deviation setting of the primary air deflector, and form a design drawing of the primary air deflector;

[0012] Step S30: Perform three-dimensional modeling of the wind chamber according to the design drawing of the primary air deflector and the traditional design drawing without the deflector, and form two sets of models for comparison;

[0013] Step S40: The Navier-Stokes equation is used to calculate the important physical data related to the coal mill production under the two model examples and compare and analyze whether the swirl guide plate meets the requirements.

[0014] In the first aspect of the present invention, as a preferred embodiment, in the step S10, when "five concentric circles with decreasing diameters are made along the radius, and the diameters are circle 1 to circle 5 from small to large respectively", the radii of circle 1 to circle 5 are increased according to the numerical rule of L1.

[0015] In the first aspect of the present invention, as a preferred embodiment, in the step S30, when "three-dimensional modeling of the wind chamber is performed according to the design drawing of the primary wind guide plate and the traditional design drawing without guide plates, and two groups of models are formed for comparison", the preparation work before calculation is done first, and then the fluent software is entered to set the model, and the Realizable k-ε model is selected for the turbulence model of the rotating flow of the airflow in the gas phase flow field.

[0016] In the first aspect of the present invention, as a preferred embodiment, in the step S30, when "three-dimensional modeling of the wind chamber is performed according to the design drawing of the primary wind guide plate and the traditional design drawing without guide plate, and two groups of models are formed for comparison", the inlet air duct and the internal cylinder are divided into two fluid domains, and the grinding bowl and the wind ring are processed as MRF rotating domains.

[0017] In the first aspect of the present invention, as a preferred embodiment, in the step S30, the rotation speed is set to 27.7r / min, the gas phase inlet of the coal mill is the velocity inlet, the velocity is calculated to be 29.18m / s based on the actual operating mass flow rate and the inlet cross-sectional area, the outlet is fully developed as the outflow, and in terms of the wall setting, the grinding bowl wall and the scraper plate and separator body wall below it are moving rotating walls, the rotation speed is set in the same rotation domain, and the remaining walls are stationary and non-slip walls.

[0018] In the first aspect of the present invention, as a preferred embodiment, in the step S30, when "three-dimensional modeling of the wind chamber is performed according to the design drawing of the primary wind deflector and the traditional design drawing without deflector to form two sets of models for comparison", the solution method selects the coupled algorithm with higher implicit solution accuracy of steady-state pressure-velocity coupling, and the convergence standard is that the convergence residual of each item is less than 10 -3 .

[0019] In the first aspect of the present invention, as a preferred embodiment, in the step S40, when "using the Navier-Stokes equation to calculate the important physical data related to the coal mill production under the two model examples and comparing and analyzing whether the swirl guide plate meets the requirements", the Navier-Stokes equation expression is as follows:

[0020]

[0021] The subscripts are the directions of the coordinate axes, and the remaining items are the physical quantities of the fluid motion parameters.

[0022] In the first aspect of the present invention, as a preferred embodiment, when "using the Navier-Stokes equation to calculate the important physical data related to the coal mill production under the two model examples and comparing and analyzing whether the swirl guide plate meets the requirements", the Realizable k-ε model based on the Reynolds time-averaged method is selected to solve the equation. In the Realizable k-ε model, the transport equations for k and ε are as follows:

[0023]

[0024] In the first aspect of the present invention, as a preferred embodiment, in the step S40, when "using the Navier-Stokes equation to calculate the important physical data related to the coal mill production under the two model examples and comparing and analyzing whether the swirl guide plate meets the requirements", a statistical table of the important physical data related to the coal mill production is generated.

[0025] In the first aspect of the present invention, as a preferred embodiment, in the step S40, when "using the Navier-Stokes equation to calculate the important physical data related to the coal mill production under the two model examples and comparing and analyzing whether the swirl guide plate meets the requirements", the inlet and outlet wind resistance and the maximum airflow velocity in the flow field are compared.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. Five concentric circles with decreasing diameters are made along the radius, and when the diameters are circle 1 to circle 5 from small to large, the radii of circle 1 to circle 5 are increased according to the numerical law of L1. The guide plate structure of the present invention has a better diversion and drainage effect for the primary air, and allows the primary air to enter the primary air chamber more orderly and uniformly.

[0028] 2. The air flow velocity distribution of each nozzle of the model equipped with a swirl guide plate of the present invention is more uniform than that of the original model. A higher air flow velocity means that the coal mill has a stronger ability to transport coal powder. At the same time, a more uniform air flow distribution can effectively reduce the uneven wear of each wind ring blade and internal components of the coal mill. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a flow chart of the present invention;

[0030] Figure 2 It is a model diagram of the present invention;

[0031] Figure 3 This is a schematic diagram of the inlet guide plate design;

[0032] Figure 4 This is a comparison chart of the inlet and outlet wind resistance of the two models;

[0033] Figure 5 This is a comparison chart of the maximum airflow velocity of the two models;

[0034] Figure 6 It is the combined velocity cloud diagram of the airflow on the cross section of the wind ring in the model with swirl guide plate;

[0035] Figure 7 It is the combined velocity cloud diagram of the cross section of the airflow on the wind ring in the original model;

[0036] Figure 8 This is the streamline diagram of the swirl guide plate air inlet. DETAILED DESCRIPTION

[0037] Below, in conjunction with the accompanying drawings and specific embodiments, the invention is further described. It should be noted that, under the premise of no conflict, the various embodiments described below or the various technical features can be arbitrarily combined to form a new embodiment. Except as otherwise specified, the materials and equipment used in this embodiment can be purchased from the market. Examples of the embodiments are shown in the accompanying drawings, in which the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0038] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present application. In the description of the present application, "plurality" means two or more, unless otherwise precisely and specifically specified.

[0039] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "connected", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, or it can be connected through an intermediary medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0040] The terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0041] like Figure 1-3 As shown in the figure, a method for optimizing the structure of the primary air inlet guide plate of a coal mill based on CFD is specifically listed for the structural optimization of the 1163 / Dyn coal mill. It should be noted that the current research on flow fields mainly adopts two methods: experimental research and numerical simulation. The former mainly uses real-time monitoring and recording of sensors at specific points in the flow field for research, while the latter is based on numerical simulation to perform theoretical simulation of the overall flow field. The latter is not restricted by experimental conditions. Through theoretical simulation, the overall flow field profile and the specific physical quantity values ​​of each area we are concerned about can be calculated and simulated. Therefore, numerical simulation has become the mainstream means of studying flow fields today. CFD is the abbreviation of Computational Fluid Dynamics, which means using computer virtual experiments to solve actual engineering needs, directly predict through numerical simulation, and provide a basis for engineering design.

[0042] On the basis of the above-established main research content of this paper, numerical simulation method is proposed to be used with the help of CFD analysis software Ansys for numerical solution. The process of using CFD to solve fluid mechanics engineering problems is generally divided into three parts: pre-processing, solver, and post-processing. Pre-processing is the construction and meshing of geometric flow model, solver is to select appropriate turbulence control equations, input known solution condition related parameters, and post-processing is to output calculated data for required physical field visualization, such as drawing temperature, velocity, pressure field, streamline trajectory missing, etc.

[0043] A CFD-based coal mill primary air inlet guide plate structure optimization method includes:

[0044] Step S10: in the inner wall of the primary air chamber of the coal mill, five concentric circles with decreasing diameters are made along the radius, and the diameters are circle 1 to circle 5 from small to large;

[0045] In the first aspect of the present invention, as a preferred embodiment, in the step S10, when "five concentric circles with decreasing diameters are made along the radius, and the diameters are circle 1 to circle 5 from small to large", the radius of circle 1 to circle 5 is increased according to the numerical law of L1. For the primary air, the guide plate structure of the present invention has a better diversion and drainage effect, so that the primary air enters the primary air chamber more orderly and uniformly. Attached Table 1 is the main structural parameters of the primary air (including the air chamber) of the coal mill.

[0046] Table 1 Main structural dimensions of primary air inlet (including air chamber volume)

[0047]

[0048] Step S20: draw an auxiliary line perpendicular to the center line of the primary air inlet, draw a tangent line through the intersection of circles 1 to 5 and the auxiliary line to the primary air outlet and extend to the primary air outlet, locate the positioning and angle deviation setting of the primary air deflector, and form a design drawing of the primary air deflector;

[0049] Step S30: Perform three-dimensional modeling of the wind chamber according to the design drawing of the primary air deflector and the traditional design drawing without the deflector, and form two sets of models for comparison;

[0050] In the first aspect of the present invention, as a preferred embodiment, in the step S30, when "three-dimensional modeling of the wind chamber is performed according to the design drawing of the primary wind deflector and the traditional design drawing without deflectors, forming two sets of models for comparison", the preparation work before calculation is done first, and then the fluent software is entered to set the model, and the Realizable k-ε model is selected for the turbulence model of the airflow rotation flow in the gas phase internal flow field. When three-dimensional modeling, the focus is on restoring the details of the internal flow domain, and the flow domain is extracted for the model, and the meshing is performed using the Meshing software, and the total number of meshes is about 1.5 million.

[0051] In the first aspect of the present invention, as a preferred embodiment, in the step S30, when "three-dimensional modeling of the wind chamber is performed according to the design drawing of the primary wind deflector and the traditional design drawing without deflectors to form two groups of models for comparison", the inlet air duct and the internal cylinder are divided into two fluid domains, and the grinding bowl and the wind ring are processed as MRF rotation domains. By solving the above equations, the inlet and outlet wind resistance, maximum airflow velocity and other important physical data related to coal mill production in the flow field under the two examples are obtained, and the advantages of the swirl deflector are analyzed by comparison.

[0052] In the first aspect of the present invention, as a preferred embodiment, in the step S30, the rotation speed is set to 27.7r / min, the gas phase inlet of the coal mill is the velocity inlet, the velocity is calculated to be 29.18m / s based on the actual operating mass flow rate and the inlet cross-sectional area, the outlet is fully developed as the outflow, and in terms of the wall setting, the grinding bowl wall and the scraper plate and separator body wall below it are moving rotating walls, the rotation speed is set in the same rotation domain, and the remaining walls are stationary and non-slip walls.

[0053] In the first aspect of the present invention, as a preferred embodiment, in the step S30, when "three-dimensional modeling of the wind chamber is performed according to the design drawing of the primary wind deflector and the traditional design drawing without deflector to form two sets of models for comparison", the solution method selects the coupled algorithm with higher implicit solution accuracy of steady-state pressure-velocity coupling, and the convergence standard is that the convergence residual of each item is less than 10 -3 Specifically, the coupled algorithm solves the momentum equation and the continuity equation simultaneously. By implicitly discretizing the pressure gradient term and the surface mass flux in the momentum equation, a fully implicit algorithm can be implemented. It is a way of solving equations and therefore cannot be expressed in a formula. Figure 4 Comparison of inlet and outlet wind resistance of the two models Figure 5 It can be seen from the maximum airflow velocity diagrams of the two models that the swirl guide plate provided in the present invention increases the wind resistance of the primary air chamber of the coal mill by nearly 1 kPa, which is about 14% higher than the wind resistance of the primary air chamber without the guide plate in the traditional method. Due to the installation of the guide plate, the interception area of ​​the primary air chamber inlet is reduced, and the airflow velocity is also increased by nearly 4 m / s.

[0054] Step S40: The Navier-Stokes equation is used to calculate the important physical data related to the coal mill production under the two model examples and compare and analyze whether the swirl guide plate meets the requirements. Figure 6 and Figure 7The velocity distribution cloud diagrams are made of the data of the combined velocity of the airflow on the cross section of the wind ring in the flow field calculated by the two models. The airflow forms a high-speed zone at the tail of the wind ring through the swirl of the wind ring and the interception effect of the tail of the wind ring. The wind ring of this model of coal mill has a total of 31 blades to form 32 high-speed airflow nozzle areas. By numbering the distance between each nozzle area and the primary air outlet, it can be seen that the 11-22 nozzle area after the inlet presents a higher combined airflow velocity, while the 1-10 and 23-32 nozzle areas have relatively low velocities. Compare the airflow velocity distribution cloud diagrams of the cross section of the wind ring of the two models. From the aspect of airflow velocity, it is obvious that the swirl guide plate of the present invention makes the airflow velocity at the outlet of the coal mill wind ring higher and the high-speed zone area larger. Comparing the uniformity of each air ring nozzle area, the airflow velocity distribution of each nozzle of the model equipped with a swirl guide plate of the present invention is more uniform than that of the original model. A higher air flow rate means that the coal mill has a stronger ability to transport coal powder, while a more uniform air flow distribution can effectively reduce the uneven wear of the air ring blades and internal components of the coal mill.

[0055] In the first aspect of the present invention, as a preferred embodiment, in the step S40, when "using the Navier-Stokes equation to calculate the important physical data related to the coal mill production under the two model examples and comparing and analyzing whether the swirl guide plate meets the requirements", the Navier-Stokes equation expression is as follows:

[0056]

[0057] The subscripts are the directions of the coordinate axes, and the remaining items are the physical quantities of the fluid motion parameters.

[0058] In the first aspect of the present invention, as a preferred embodiment, when "using the Navier-Stokes equation to calculate the important physical data related to the coal mill production under the two model examples and comparing and analyzing whether the swirl guide plate meets the requirements", the Realizable k-ε model based on the Reynolds time-averaged method is selected to solve the equation. In the Realizable k-ε model, the transport equations for k and ε are as follows:

[0059]

[0060] In the first aspect of the present invention, as a preferred embodiment, in the step S40, when "using the Navier-Stokes equation to calculate the important physical data related to the coal mill production under the two model examples and comparing and analyzing whether the swirl guide plate meets the requirements", a statistical table of the important physical data related to the coal mill production is generated.

[0061] In the first aspect of the present invention, as a preferred embodiment, in the step S40, when "using the Navier-Stokes equation to calculate the important physical data related to the coal mill production under the two model examples and comparing and analyzing whether the swirl guide plate meets the requirements", the inlet and outlet wind resistance and the maximum airflow velocity in the flow field are compared. By observing Figure 8 From the air flow streamline diagram of the primary air inlet in which the swirl guide plate is arranged in the present invention, it can be seen that the swirl guide plate has the effect of diverting and guiding the airflow when the airflow passes through the air inlet. The airflow can not only enter the primary air chamber evenly after passing through the swirl guide plate, but also be affected by the swirl, which greatly reduces the momentum loss of the primary air at the air inlet and increases the primary air volume and wind speed.

[0062] The above-mentioned embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. A CFD-based method for optimizing the structure of the primary air inlet guide plate of a coal mill, characterized in that: include: Step S10: in the inner wall of the primary air chamber of the coal mill, five concentric circles with decreasing diameters are made along the radius, and the diameters are circle 1 to circle 5 from small to large; Step S20: draw an auxiliary line perpendicular to the center line of the primary air inlet, draw a tangent line through the intersection of circles 1 to 5 and the auxiliary line to the primary air outlet and extend to the primary air outlet, locate the positioning and angle deviation setting of the primary air deflector, and form a design drawing of the primary air deflector; Step S30: Perform three-dimensional modeling of the wind chamber according to the design drawing of the primary air deflector and the traditional design drawing without the deflector, and form two sets of models for comparison; Step S40: The Navier-Stokes equation is used to calculate the important physical data related to the coal mill production under the two model examples and compare and analyze whether the swirl guide plate meets the requirements.

2. The CFD-based coal mill primary air inlet guide plate structure optimization method according to claim 1, characterized in that: In the step S10, when "five concentric circles with decreasing diameters are made along the radius, and the diameters are circle 1 to circle 5 from small to large respectively", the radii of circle 1 to circle 5 are increased according to the numerical rule of L1.

3. The CFD-based coal mill primary air inlet guide plate structure optimization method according to claim 2, characterized in that: In the step S30, when "three-dimensional modeling of the wind chamber is performed according to the design drawing of the primary wind guide plate and the traditional design drawing without guide plates to form two sets of models for comparison", the preparation work before calculation is done first, and then the fluent software is entered to set the model, and the Realizable k-ε model is selected for the turbulence model of the rotating flow of the airflow in the gas phase flow field.

4. The CFD-based coal mill primary air inlet guide plate structure optimization method according to claim 2, characterized in that: In the step S30, when "three-dimensional modeling of the wind chamber is performed according to the design drawing of the primary wind guide plate and the traditional design drawing without guide plate to form two sets of models for comparison", the inlet air duct and the internal cylinder are divided into two fluid domains, and the grinding bowl and the wind ring are processed as MRF rotating domains.

5. The CFD-based coal mill primary air inlet guide plate structure optimization method according to claim 4, characterized in that: In the step S30, the rotation speed is set to 27.7r / min, the gas phase inlet of the coal mill is the velocity inlet, the speed is calculated to be 29.18m / s based on the actual working mass flow rate and the inlet cross-sectional area, the outlet is fully developed as the outflow, and in terms of wall setting, the grinding bowl wall and the scraper plate and separator body wall below it are moving rotating walls, the rotation speed is set to the same rotation domain, and the remaining walls are stationary and non-slip walls.

6. The CFD-based coal mill primary air inlet guide plate structure optimization method according to claim 1, characterized in that: In the step S30, when "three-dimensional modeling of the wind chamber is performed according to the design drawing of the primary wind deflector and the traditional design drawing without deflector to form two sets of models for comparison", the solution method selects the coupled algorithm with higher implicit solution accuracy of steady-state pressure-velocity coupling, and the convergence standard is that the convergence residual of each item is less than 10 -3 .

7. The CFD-based coal mill primary air inlet guide plate structure optimization method according to claim 1, characterized in that: In the step S40, when "using the Navier-Stokes equation to calculate the important physical data related to the coal mill production under the two model examples and comparing and analyzing whether the swirl guide plate meets the requirements", the Navier-Stokes equation expression is as follows: The subscripts are the directions of the coordinate axes, and the remaining items are the physical quantities of the fluid motion parameters.

8. The CFD-based coal mill primary air inlet guide plate structure optimization method according to claim 1, characterized in that: In "Using the Navier-Stokes equation to calculate the important physical data related to coal mill production under two model examples and comparing and analyzing whether the swirl guide plate meets the requirements", the Realizable k-ε model based on the Reynolds time-averaged method is selected to solve the equation. In the Realizable k-ε model, the transport equations for k and ε are as follows:

9. The CFD-based coal mill primary air inlet guide plate structure optimization method according to claim 1, characterized in that: In the step S40, when "using the Navier-Stokes equation to calculate the important physical data related to the coal mill production under the two model examples and comparing and analyzing whether the swirl guide plate meets the requirements", a statistical table of the important physical data related to the coal mill production is generated.

10. The CFD-based coal mill primary air inlet guide plate structure optimization method according to claim 1, characterized in that: In the step S40, when "using the Navier-Stokes equation to calculate the important physical data related to the coal mill production under the two model examples and comparing and analyzing whether the swirl guide plate meets the requirements", the inlet and outlet wind resistance and the maximum airflow velocity in the flow field are compared.

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