Method for optimizing angle of spoiler blade in flow-state particulate pollutant detector

Abstract

The invention discloses a method for optimizing the angle of a turbulent flow blade in a flow-state particulate pollutant detector, relates to the technical field of detection of particulate matters in fluid, and aims to solve the problem that the accuracy of particulate pollutant detection is influenced by the influence of the angle of the turbulent flow blade of the flow-state particulate pollutant detector on a flow field and particle distribution. The method comprises the following steps: 1, establishing a three-dimensional model of a flow field; 2, the included angles between the spoiler blades and the radial section of the mixing sleeve are set to be a plurality of different angles; 3, setting limiting conditions of a flow field; 4, performing grid division on the flow field area, and performing network encryption on the narrow space; 5, carrying out simulation operation to obtain the velocity distribution of the flow field at different angles and the mixing state of solid particles; and 6, analyzing according to the simulation result to obtain the flow field state of the fluid before reaching the spoiler blade and the running state of the solid particles before reaching the spoiler blade at different angles of the spoiler blade. The invention provides an optimal spoiler blade angle range for uniformly mixing solid particles in a flow field.

Description

Technical Field

[0001] The present invention relates to the technical field of detecting particulate matter in fluids, and particularly relates to an optimization method for the angle of turbulence-generating vanes in a fluid particulate pollutant detector. Background Art

[0002] In industrial production, it is often necessary to detect the content of solid particulate matter in fluids. During the research process, it was found that in the actual flow field, the sizes of the solid particulate matter involved are different, and during the process of flowing with the fluid, the solid particulate matter will sink under the action of gravity and it is difficult to mix evenly in the fluid, resulting in higher or lower values of the measured particulate pollutants and a large deviation in the detection results. The utility model patent with the patent application number 202422943093.3 discloses "a detector for detecting particle size in a flow field". A turbulence-generating vane is provided in this device, which can turn into a turbulent flow rotating around the axial direction of the pipeline before the air flow passes through the detection probe, thereby forming a stirring effect to make the particles in the gas mix evenly. However, the optimization range of the angle of the turbulence-generating vane is not clearly defined in this document. By changing the structure and energy distribution of the fluid flow through different angles of the vane, it significantly affects the operation state of the flow field and the suspension and mixing effect of the particles. Therefore, how to determine the most suitable vane tilt angle under common pressures to improve the particle mixing uniformity is a problem that needs to be solved currently. Summary of the Invention

[0003] The present invention aims to solve the influence of the angle of the turbulence-generating vane of a fluid particulate matter detector on the accuracy of particulate pollutant detection in the prior art, and further proposes an optimization method for the angle of the turbulence-generating vane in a fluid particulate pollutant detector.

[0004] The technical solution adopted by the present invention to solve the above problems is as follows:

[0005] An optimization method for the angle of turbulence-generating vanes in a fluid particulate pollutant detector, the fluid particulate pollutant detector includes a mixing tube, a detection probe, a detection pipe section, and a pressure-reducing pipe section. The mixing tube, the detection pipe section, and the pressure-reducing pipe section are connected in sequence from left to right. The detection probe is provided on the detection pipe section, and the turbulence-generating vanes are installed in the mixing tube; the turbulence-generating vanes are arranged in a circular array by a plurality of vanes. The outer ends of the plurality of vanes are evenly arranged and installed on the inner wall of the mixing tube, and the inner ends of the plurality of vanes are concentrated at the axis position of the mixing tube and are close to each other;

[0006] Each vane consists of a vane body and a vane column. The vane body is a thin sheet structure, and the vane column is fixed at one end of the vane body; the length of each vane is less than the radius of the mixing tube; the aspect ratio of the length to the width of the vane body is 3:1. An optimization method for the angle of turbulence-generating vanes in a fluid particulate pollutant detector includes the following steps:

[0007] Step 1: Establish a three-dimensional model of the flow field;

[0008] Step 2: Set the angle between the spoiler vane and the radial section of the mixing sleeve to multiple different angles;

[0009] Step 3: Set the limiting conditions of the flow field;

[0010] Step 4: Mesh the flow field region and encrypt the network for narrow spaces;

[0011] Step 5: Conduct simulation operations to obtain the velocity distribution of the flow field and the mixing state of solid particles at different angles;

[0012] Step 6: Analyze according to the simulation results to obtain the flow field state of the fluid before reaching the spoiler vane and the running state of the solid particles before reaching the spoiler vane at different spoiler vane angles.

[0013] Further, in Step 2, the angles between the spoiler vane and the radial section of the mixing sleeve are sequentially set to 90°, 80°, 70°, 60°, 50°, 40°, 30°, 20°, and 10°.

[0014] Further, in Step 3, the limiting conditions of the flow field include that the fluid is air, the molecular mass is 0.02896 kg / mol, the dynamic viscosity is 1.85×10 -5 Pa·s, the absolute pressure value at the inlet is 111325 Pa, the outlet is set to the ambient pressure, the absolute pressure value is 101325 Pa, and the pressure difference between the two ends is 10000 Pa.

[0015] Further, in Step 6, analyze according to the simulation results to determine that the optimal angle range of the spoiler vane is 40° to 60° to achieve the uniform distribution of solid particles in front of the detection probe.

[0016] Further, the density of the solid particles is 7800 kg / m 3 , the diameter is 0.0001 m, the injection rate is 0.0001 kg / s, and the initial velocity of the injected particles is 0 m / s.

[0017] The beneficial effects of the present invention are as follows: Through the finite element analysis method, the present invention not only studies the angle of the spoiler vane and the mixing situation of solid particles in the flow field under given conditions, provides the optimal angle range of the spoiler vane for the uniform mixing of solid particles in the flow field, and through simulation analysis, determines that the optimal angle range of the spoiler vane is 40° - 60°, significantly improving the particle mixing uniformity. Description of the Drawings

[0018] Figure 1 is the overall structural schematic diagram of the detector of the present invention;

[0019] Figure 2 It is a schematic structural diagram of a single blade of the present invention;

[0020] Figure 3 It is a three-dimensional model diagram of the present invention when the blade angle is 90°;

[0021] Figure 4 It is a diagram for setting the inlet and outlet pressure values of the present invention when the blade angle is 90°;

[0022] Figure 5 It is a diagram of the flow field grid division of the present invention when the blade angle is 90°;

[0023] Figure 6 It is a simulation operation diagram of the present invention when the blade angle is 90°;

[0024] Figure 7 It is the flow field velocity condition of three cross-sections of the present invention when the blade angle is 90°;

[0025] Figure 8 It is the flow field velocity condition of the cross-section along the flow direction of the present invention when the blade angle is 90°;

[0026] Figure 9 It is the flow field velocity condition of the radial cross-section 85 mm in front of the measuring instrument of the present invention when the blade angle is 90°;

[0027] Figure 10 It is the flow field velocity condition of the radial cross-section 300 mm behind the measuring instrument of the present invention when the blade angle is 90°;

[0028] Figure 11 It is the solid particle mixing state of the present invention when the blade angle is 90°;

[0029] Figure 12 It is the flow field velocity condition of three cross-sections of the present invention when the blade angle is 80°;

[0030] Figure 13 It is the flow field velocity condition of the cross-section along the flow direction of the present invention when the blade angle is 80°;

[0031] Figure 14 It is the flow field velocity condition of the radial cross-section 85 mm in front of the measuring instrument of the present invention when the blade angle is 80°;

[0032] Figure 15 It is the flow field velocity condition of the radial cross-section 300 mm behind the measuring instrument of the present invention when the blade angle is 80°

[0033] Figure 16 It is the solid particle mixing state of the present invention when the blade angle is 80°;

[0034] Figure 17 It is the flow field velocity condition of three cross-sections of the present invention when the blade angle is 70°;

[0035] Figure 18 is the velocity condition of the flow field of the cross-section along the flow direction with a blade angle of 70° in the present invention;

[0036] Figure 19 is the velocity condition of the flow field of the radial cross-section 85 mm in front of the measuring instrument with a blade angle of 70° in the present invention;

[0037] Figure 20 is the velocity condition of the flow field of the radial cross-section 300 mm behind the measuring instrument with a blade angle of 70° in the present invention;

[0038] Figure 21 is the solid particle mixing state with a blade angle of 70° in the present invention;

[0039] Figure 22 is the velocity condition of the flow field of three cross-sections with a blade angle of 60° in the present invention;

[0040] Figure 23 is the velocity condition of the flow field of the cross-section along the flow direction with a blade angle of 60° in the present invention;

[0041] Figure 24 is the velocity condition of the flow field of the radial cross-section 85 mm in front of the measuring instrument with a blade angle of 60° in the present invention;

[0042] Figure 25 is the velocity condition of the flow field of the radial cross-section 300 mm behind the measuring instrument with a blade angle of 60° in the present invention;

[0043] Figure 26 is the solid particle mixing state with a blade angle of 60° in the present invention;

[0044] Figure 27 is the velocity condition of the flow field of three cross-sections with a blade angle of 50° in the present invention;

[0045] Figure 28 is the velocity condition of the flow field of the cross-section along the flow direction with a blade angle of 50° in the present invention;

[0046] Figure 29 is the velocity condition of the flow field of the radial cross-section 85 mm in front of the measuring instrument with a blade angle of 50° in the present invention;

[0047] Figure 30 is the velocity condition of the flow field of the radial cross-section 300 mm behind the measuring instrument with a blade angle of 50° in the present invention;

[0048] Figure 31 is the solid particle mixing state with a blade angle of 50° in the present invention;

[0049] Figure 32 is the velocity condition of the flow field of three cross-sections with a blade angle of 40° in the present invention;

[0050] Figure 33 It is the velocity condition of the flow field of the cross-section along the flow direction with a blade included angle of 40° in the present invention;

[0051] Figure 34 It is the velocity condition of the radial cross-section of the flow field at a position 85 mm in front of the measuring instrument with a blade included angle of 40° in the present invention;

[0052] Figure 35 It is the velocity condition of the radial cross-section of the flow field at a position 300 mm behind the measuring instrument with a blade included angle of 40° in the present invention;

[0053] Figure 36 It is the solid particle mixing state with a blade included angle of 40° in the present invention;

[0054] Figure 37 It is the velocity condition of the flow field of three cross-sections with a blade included angle of 30° in the present invention;

[0055] Figure 38 It is the velocity condition of the cross-section along the flow direction with a blade included angle of 30° in the present invention;

[0056] Figure 39 It is the velocity condition of the radial cross-section of the flow field at a position 85 mm in front of the measuring instrument with a blade included angle of 30° in the present invention;

[0057] Figure 40 It is the velocity condition of the radial cross-section of the flow field at a position 300 mm behind the measuring instrument with a blade included angle of 30° in the present invention;

[0058] Figure 41 It is the solid particle mixing state with a blade included angle of 30° in the present invention;

[0059] Figure 42 It is the velocity condition of the flow field of three cross-sections with a blade included angle of 20° in the present invention;

[0060] Figure 43 It is the velocity condition of the cross-section along the flow direction with a blade included angle of 20° in the present invention;

[0061] Figure 44 It is the velocity condition of the radial cross-section of the flow field at a position 85 mm in front of the measuring instrument with a blade included angle of 20° in the present invention;

[0062] Figure 45 It is the velocity condition of the radial cross-section of the flow field at a position 300 mm behind the measuring instrument with a blade included angle of 20° in the present invention;

[0063] Figure 46 It is the solid particle mixing state with a blade included angle of 20° in the present invention;

[0064] Figure 47 It is the velocity condition of the flow field of three cross-sections with a blade included angle of 10° in the present invention;

[0065] Figure 48 It is the velocity condition of the cross-sectional flow field along the flow direction at a blade angle of 10° of the present invention.

[0066] Figure 49 It is the velocity condition of the radial cross-sectional flow field at a distance of 85 mm in front of the measuring instrument at a blade angle of 10° of the present invention.

[0067] Figure 50 It is the velocity condition of the radial cross-sectional flow field at a distance of 300 mm behind the measuring instrument at a blade angle of 10° of the present invention.

[0068] Figure 51 It is the solid particle mixing state at a blade angle of 10° of the present invention. Specific implementation mode

[0069] Example 1: When the angle between the blade body 5-1 and the radial cross-section of the mixing tube is 90°, the operation of the flow field is analyzed as follows:

[0070] Step 1: Use SolidWorks to establish a three-dimensional model of the gas-fluid particle pollutant detector: The gas-fluid particle pollutant detector includes: a mixing tube 1, a detection probe 2, a detection pipe section 3, and a pressure-reducing pipe section 4. The spoiler blades 5 are installed in the mixing tube 1; the spoiler blades 5 are arranged in a circular array by a plurality of blades. The outer ends of the plurality of blades are evenly arranged and installed on the inner wall of the mixing tube 1. The inner ends of the plurality of blades are concentrated at the axis position of the mixing tube and are close to each other;

[0071] Each blade is composed of a blade body 5-1 and a blade column 5-2. The blade body 5-1 is a thin sheet structure, and the blade column 5-2 is fixed at one end of the blade body 5-1; the length of each blade is less than the radius of the mixing tube 1; the aspect ratio of the blade body 5-1 is 3:1; and an inflow pipe 6 is added to the front end of the mixing tube 1, and an outflow pipe 7 is added to the rear end of the pressure-reducing pipe section 4; after the fluid enters the "gas-fluid particle pollutant detector" from the inflow pipe 6, it then flows out from the outflow pipe 7.

[0072] Step 2: As Figure 3 shown, change the angle between the blade body 5-1 and the radial cross-section of the mixing tube 1 in SolidWorks to establish a three-dimensional model with an angle of 90° between the blade body 5-1 and the radial cross-section of the mixing tube.

[0073] Step 3: Set the limiting conditions of the flow field. As Figure 4 shown, set the fluid as air in SolidWorks Flow Simulation, with a molecular mass of 0.02896 kg / mol and a dynamic viscosity of 1.85×10 -5Pa·s. The absolute pressure value at the inlet is 111325 Pa. The outlet is set to the ambient pressure with an absolute pressure value of 101325 Pa, and the pressure difference between the two ends is 10000 Pa.

[0074] Step 4: Mesh the flow field region and refine the mesh for the narrow space; as Figure 5 shown, in the mesh project of SolidWorks Flow Simulationd, complete meshing of the flow field region and refine the mesh for the narrow space;

[0075] Step 5: Perform simulation calculations to obtain the velocity distribution of the flow field and the mixing state of solid particles at different angles; as Figure 6 shown, after completing the preparatory work in Steps 1 - 4 above, click the run button in SolidWorks Flow Simulationd, and then the simulation calculations can be performed according to the set conditions to obtain the flow field state;

[0076] Step 6: Analyze according to the simulation results to obtain the flow field state of the fluid before reaching the spoiler vanes and the running state of the solid particles before reaching the spoiler vanes at different spoiler vane angles, specifically as follows:

[0077] As Figures 7 - 10 shown, after completing the simulation calculations in Step 5, use the sectional view in the result options to view the simulation calculation results and observe the velocity change in the flow field at a vane angle of 90°:

[0078] As Figure 7 shown, three positions are selected respectively to observe the flow state of the flow field, namely the velocity contour maps along the flow direction, longitudinally, and radially. The velocity contour map of the radial cross-section is located behind the spoiler vane 5 and 85 mm in front of the measuring instrument. The velocity contour map of the radial cross-section is inside the pressure-reducing pipe section 4 and 300 mm behind the detection probe 2;

[0079] As Figure 8 shown, the velocity contour map of the longitudinal cross-section along the flow direction is presented. By analyzing this velocity contour map, it can be found that after the fluid passes through the spoiler vane 5, the velocity decreases slightly and then basically returns to the velocity before encountering the spoiler vane 5. Inside the detection pipe section 3, due to the obstruction of the detection probe 2, the velocity of the upper fluid slows down significantly and turbulent flow appears, while the velocity of the lower fluid increases significantly. Inside the pressure-reducing pipe section 4, the flow field space increases, the pressure decreases, the upper flow velocity is slow and mainly turbulent, and the lower flow velocity is fast and mainly laminar. When the fluid enters the enlarged radial cross-section area of the pressure-reducing pipe section 4, a local eddy will be formed in the upper region. This eddy will not only hinder the flow of the upper fluid but also compress the flow space of the lower fluid, thus hindering the outflow of the fluid;

[0080] As Figure 9 shown, it shows the velocity contour map of the radial cross-section flow field at a position 85 mm in front of the distance measuring instrument and behind the spoiler blade 5. This cross-section is within the detection pipe section 3. By analyzing this velocity contour map, it can be found that after the fluid passes through the spoiler blade 5, two vortices that are close to the central region and symmetric about the left and right will be formed in the radial plane. This phenomenon conforms to the Karman vortex street phenomenon formed after the fluid flows around an obstacle;

[0081] Since the detection pipe section 3 is a hollow cylinder and the cross-section of the flow field in this section is circular, the region from the center of the cross-section to 1 / 3 of the inner wall radius of the detection pipe section 3 is defined as the central region, the region from 1 / 3 of the inner wall radius of the detection pipe section 3 to 2 / 3 of the inner wall radius of the detection pipe section 3 is defined as the middle layer region, and the region from 2 / 3 of the inner wall radius of the detection pipe section 3 to the inner wall of the detection pipe section 3 is defined as the outer layer region; the velocity in the central region of this cross-section is approximately 123 - 130 m / s, and the velocity in the middle layer region is approximately 130 - 132 m / s. Due to the influence of the inner wall friction, the velocity in the outer layer region gradually decreases from 132 m / s to 0 m / s; in this state, the maximum velocity of the flow field is roughly located at the position of 2 / 3 of the inner wall radius of the detection pipe section 3 from the center of the circle;

[0082] As Figure 10 shown, it shows the velocity contour map of the radial cross-section flow field inside the pressure reduction pipe section 4 and 300 mm behind the detection probe 2. By analyzing this velocity contour map, it can be found that due to the obstruction of the detection probe 2, the pressure drop generated by the upper fluid is more than that of the lower part and the flow velocity is also slower than that of the lower part, causing the fluid in this region to flow upward, forming a symmetric flow field on the left and right; the radial cross-section map 300 mm behind the distance measuring instrument is marked with the time scale of a clock dial. The orientation of the top detection probe 2 is defined as the 12 o'clock position, and the bottom is defined as the 6 o'clock position. At this time, the center point of the flow field backflow is located at the 12 o'clock position directly above the flow field;

[0083] To test the operating conditions of solid particle pollutants in the flow field when the included angle of the spoiler blade is 90°, solid particles are injected at the bottom of the front end of the inflow pipe 5, and finite element simulation is used to obtain the operating conditions of the solid particles in the flow field, and then whether the particles in the flow field will be mixed evenly at this included angle of the spoiler blade;

[0084] Here, the density of the solid particles is set to 7800 kg / m 3 , the diameter is 0.0001 m, the injection rate is 0.0001 kg / s, and the initial velocity of the injected particles is 0 m / s; the injection position of the solid particles is set at the bottom of the front end of the inflow pipe 5. This position is relatively extreme, which is convenient for detecting the mixing effect of the spoiler blade 5 on the solid particles; the diameter of the inflow pipe 5 is the same as that of the mixing tube 1, and the distance between the injection position of the solid particles and the spoiler blade 5 is 4 times the diameter of the mixing tube 1;

[0085] The injected solid particles will first be in the lower layer of the flow field and move forward with the fluid to the position of the turbulence blade 5. After passing through the turbulence blade 5, the flow field will change. The distribution of solid particles in the flow field after passing through the turbulence blade 5 can be observed by finite element simulation;

[0086] The simulation operation results are as Figure 11 shown. By observing the movement of solid particles in the flow field, it can be seen that after the solid particles enter the inflow pipe 5, they are basically in the lower layer position of the inflow pipe 5. After passing through the turbulence blade 5, they continue to be in the lower 1 / 3 position of the flow field. When the included angle of the turbulence blade is 90°, the mixing effect on the solid particles is not obvious, and the solid particles cannot form a uniform mixture before reaching the detection probe 2. In addition, at this time, the turbulence blade 5 does not produce an obvious block on the solid particles, and there will be no phenomenon that the solid particles hit the turbulence blade 5 and rebound.

[0087] Example 2: When the included angle between the blade body 5-1 and the radial section of the mixing tube is 80°, the operation of the flow field is analyzed as follows:

[0088] A three-dimensional model with an included angle of 80° between the blade body 5-1 and the radial section of the mixing tube is established; the fluid is set as air, the molecular mass is 0.02896 kg / mol, the dynamic viscosity is 1.85×10 -5 Pa·s, the inlet pressure value is 111325 Pa, the outlet is set as the ambient pressure, the pressure value is 101325 Pa, and the pressure difference between the two ends is 10000 Pa; the flow field area is meshed, and the mesh is encrypted in the narrow space; the simulation operation is carried out according to the set conditions to obtain the flow field state;

[0089] As Figures 12 - 15 shown, view the simulation operation results and observe the velocity change in the flow field;

[0090] As Figure 12 shown, three positions are selected respectively to observe the flow state of the flow field, namely the velocity cloud diagrams along the flow direction, longitudinally, and radially. The velocity cloud diagram of the radial section of the flow field is located 85 mm in front of the measuring instrument behind the turbulence blade 5, and the velocity cloud diagram of the radial section of the flow field is 300 mm behind the detection probe 2 in the pressure reduction pipe section 4;

[0091] As Figure 13 shown, the velocity cloud diagram of the longitudinal section along the flow direction is shown. It can be found from it that the local eddy current in the pressure reduction pipe section 4 is slightly reduced,

[0092] Figure 14Highlights the radial cross-section flow field velocity contour map located 85 mm in front of the distance measuring instrument and behind the spoiler blade 5. By observing this contour map, it can be found that after the fluid passes through the spoiler blade with an included angle of 80°, circumferential rotation has occurred. The velocity in the central region is approximately 123 - 128 m / s, the velocity in the middle layer region is approximately 128 - 131 m / s, and the velocity in the outer layer region gradually decreases from 131 m / s to 0 m / s; in this state, the maximum velocity of the flow field is roughly located at a position that is 2 / 3 of the inner wall radius of the detection pipe section 3 from the center of the circle;

[0093] Figure 15 Highlights the radial cross-section flow field velocity contour map inside the pressure reduction pipe section 4, 300 mm behind the detection probe 2. By observing this contour map, it can be found that the circumferentially rotating flow field has exerted a squeezing effect on the local eddy current inside the pressure reduction pipe section 4, and the center point of the backflow has been pressed to a position between 11 o'clock and 12 o'clock. The region with a lower flow velocity is also located in the fan-shaped region in the direction of 11 o'clock to 12 o'clock;

[0094] As Figure 16 shown, the flow state diagram of the solid particles in the flow field after injection is obtained by simulation. It can be found from the figure that before reaching the spoiler blade 5, some solid particles have moved to the upper layer of the flow field, but the main part is still in the lower layer of the flow field; in addition, at this time, the spoiler blade 5 does not have an obvious blocking effect on the solid particles, and there will be no phenomenon of the solid particles hitting the spoiler blade 5 and rebounding.

[0095] Example 3: When the included angle between the blade body 5-1 and the radial cross-section of the mixing tube is 70°, the operation of the flow field is analyzed as follows:

[0096] A three-dimensional model with an included angle of 70° between the blade body 5-1 and the radial cross-section of the mixing tube is established; the fluid is set as air, with a molecular mass of 0.02896 kg / mol and a dynamic viscosity of 1.85×10 -5 Pa·s, the inlet pressure value is 111325 Pa, the outlet is set as the ambient pressure with a pressure value of 101325 Pa, and the pressure difference between the two ends is 10000 Pa; the flow field region is meshed, and the mesh is refined for the narrow space; the simulation operation is carried out according to the set conditions to obtain the flow field state;

[0097] As Figures 17 - 20 shown, check the simulation operation results and observe the velocity change situation in the flow field;

[0098] As Figure 17As shown in the figure, three positions are respectively selected to observe the flow state of the flow field, namely the velocity cloud diagrams of the flow velocity along the flow direction, longitudinal direction, and radial section, the velocity cloud diagram of the radial section flow field at 85 mm in front of the distance measuring instrument and behind the spoiler blade 5, and the velocity cloud diagram of the radial section flow field at 300 mm behind the detection probe 2 in the pressure-reducing pipe section 4;

[0099] Figure 18 The velocity cloud diagram of the longitudinal section along the flow direction is highlighted. It can be found from it that the local eddy current in the pressure-reducing pipe section 4 is slightly reduced.

[0100] Figure 19 The velocity cloud diagram of the radial section flow field at 85 mm in front of the distance measuring instrument and behind the spoiler blade 5 is highlighted. By observing this cloud diagram, it can be found that after the fluid passes through the spoiler blade with an angle of 70°, there is an enhanced circumferential rotation. The velocity in the central region is about 117 - 123 m / s, the velocity in the middle layer region is about 123 - 127 m / s, and the velocity in the outer layer region gradually increases from 127 m / s to 129 m / s and then gradually decreases from 129 m / s to 0 m / s; in this state, the maximum velocity of the flow field is roughly located at the position of 7 / 8 of the inner wall radius of the detection pipe section 3 from the center of the circle;

[0101] Figure 20 The velocity cloud diagram of the radial section flow field at 300 mm behind the detection probe 2 in the pressure-reducing pipe section 4 is highlighted. By observing this cloud diagram, it can be found that the circumferentially rotating flow field has an extrusion effect on the local eddy current in the pressure-reducing pipe section 4, and the center point of the backflow is pressed to the 11 o'clock direction, and the region with a lower flow velocity is also in the fan-shaped region in the 11 o'clock direction;

[0102] As Figure 21 shown, the flow state diagram of solid particles in the flow field after injection is obtained by simulation. It can be found from the figure that before reaching the spoiler blade 5, the solid particles mainly move in the middle layer, and some have moved upward; in addition, although the spoiler blade 5 has a slight blocking effect on the solid particles at this time, there is almost no obvious rebound phenomenon after the solid particles hit the spoiler blade 5;

[0103] Example 4: When the angle between the blade body 5-1 and the radial section of the mixing tube is 60°, the operation of the flow field is analyzed as follows:

[0104] A three-dimensional model with an angle of 60° between the blade body 5-1 and the radial section of the mixing tube is established; the fluid is set as air, with a molecular mass of 0.02896 kg / mol and a dynamic viscosity of 1.85×10 -5Pa·s, the inlet pressure value is 111325 Pa, the outlet is set to the ambient pressure with a pressure value of 101325 Pa, and the pressure difference between the two ends is 10000 Pa; the flow field area is meshed, and the mesh is refined for the narrow space; simulation calculations are performed according to the set conditions to obtain the flow field state;

[0105] As Figures 22 - 25 shown, view the results of the simulation calculations and observe the velocity changes in the flow field;

[0106] As Figure 22 shown, three positions are respectively selected to observe the flow state of the flow field, namely the velocity cloud diagrams of the flow direction, longitudinal direction, and radial section, the velocity cloud diagram of the radial section of the flow field at 85 mm in front of the measuring instrument behind the spoiler blade 5, and the velocity cloud diagram of the radial section of the flow field at 300 mm behind the detection probe 2 in the pressure reduction pipe section 4;

[0107] Figure 23 The velocity cloud diagram of the longitudinal section along the flow direction is emphatically shown. It can be found from it that the local eddy current in the pressure reduction pipe section 4 is significantly reduced and moves towards the pipe axis region.

[0108] Figure 24 The velocity cloud diagram of the radial section of the flow field at 85 mm in front of the measuring instrument behind the spoiler blade 5 is emphatically shown. Observing this cloud diagram, it can be found that after the fluid passes through the spoiler blade with an included angle of 60°, circumferential rotation is generated. The velocity in the central region is about 112 - 120 m / s, the velocity in the middle layer region is about 120 - 126 m / s, and the velocity in the outer layer region gradually increases from 126 m / s to 128 m / s and then gradually decreases from 128 m / s to 0 m / s; in this state, the maximum velocity of the flow field is roughly located at the position of 7 / 8 of the inner wall radius of the detection pipe section 3 from the center of the circle.

[0109] Figure 25 The velocity cloud diagram of the radial section of the flow field at 300 mm behind the detection probe 2 in the pressure reduction pipe section 4 is emphatically shown. Observing this cloud diagram, it can be found that the circumferentially rotating flow field continues to exert a squeezing effect on the local eddy current in the pressure reduction pipe section 4, and the center point of the backflow moves to the pipe axis region and the direction of 10 o'clock above, and the region with a lower flow velocity is oppressed to the 10 o'clock direction.

[0110] As Figure 26 shown, the flow state diagram of the solid particles in the flow field after injection is obtained by simulation. It can be found from the figure that before reaching the spoiler blade 5, most of the solid particles start to move from the bottom of the flow field to the upper layer of the flow field. When reaching the position of the detection probe 2, the solid particles are already evenly mixed in the flow field; in addition, at this time, although the spoiler blade 5 exerts a slight block on the solid particles, only a small amount of rebound occurs when the solid particles impact the spoiler blade 5.

[0111] Example 5: When the angle between the blade body 5-1 and the radial cross-section of the mixing tube is 50°, the flow field operation is analyzed as follows:

[0112] A three-dimensional model with an angle of 50° between the blade body 5-1 and the radial cross-section of the mixing tube is established; the fluid is set as air, the molecular mass is 0.02896 kg / mol, the dynamic viscosity is 1.85×10 -5 Pa·s, the inlet pressure value is 111325 Pa, the outlet is set as the ambient pressure, the pressure value is 101325 Pa, and the pressure difference between the two ends is 10000 Pa; the flow field area is meshed, and the narrow space is meshed densely; the simulation operation is carried out according to the set conditions to obtain the flow field state;

[0113] As Figures 27 - 30 shown, view the simulation operation results and observe the velocity change in the flow field;

[0114] As Figure 27 shown, three positions are selected to observe the flow state of the flow field, namely the velocity cloud diagrams of the flow direction, longitudinal direction, and radial section, the flow field velocity cloud diagram of the radial cross-section 85 mm in front of the distance measuring instrument behind the spoiler blade 5, and the flow field velocity cloud diagram of the radial cross-section 300 mm behind the detection probe 2 in the pressure reduction pipe section 4;

[0115] Figure 28 The velocity cloud diagram of the longitudinal section along the flow direction is highlighted. It can be found from this that the local eddy current in the pressure reduction pipe section 4 is significantly reduced and moves towards the pipe axis region,

[0116] Figure 29 The flow field velocity cloud diagram of the radial cross-section 85 mm in front of the distance measuring instrument behind the spoiler blade 5 is highlighted. Observing this cloud diagram, it can be found that after the fluid passes through the spoiler blade with an angle of 50°, circumferential rotation is generated. The velocity in the central region is about 87 - 101 m / s, the velocity in the middle layer region is about 101 - 116 m / s, and the velocity in the outer layer region gradually increases from 116 m / s to 125 m / s and then gradually decreases from 125 m / s to 0 m / s; in this state, the maximum velocity of the flow field is roughly located at the position of 7 / 8 of the inner wall radius of the detection pipe section 3 from the center of the circle;

[0117] Figure 30 The flow field velocity cloud diagram of the radial cross-section 300 mm behind the detection probe 2 in the pressure reduction pipe section 4 is highlighted. Observing this cloud diagram, it can be found that the circumferentially rotating flow field continues to exert a squeezing effect on the local eddy current in the pressure reduction pipe section 4, and the center point of the backflow moves to the pipe axis region, and the region with a lower flow velocity is pressed to the 10 o'clock direction;

[0118] As Figure 31As shown in the figure, a flow state diagram of solid particles in the flow field after injection is obtained by simulation. It can be found from the figure that the solid particles are well mixed before reaching the position of the detection probe 2 after passing through the spoiler blade 5, which can meet the requirements of solid particle detection. However, due to the decrease in the angle of the spoiler blade 5, only a small amount of solid particles rebound when hitting the spoiler blade 5;

[0119] Example 6: When the angle between the blade body 5-1 and the radial cross-section of the mixing tube is 40°, the operation of the flow field is analyzed as follows:

[0120] A three-dimensional model with an angle of 40° between the blade body 5-1 and the radial cross-section of the mixing tube is established; the fluid is set as air, with a molecular mass of 0.02896 kg / mol and a dynamic viscosity of 1.85×10 -5 Pa·s, the inlet pressure value is 111325 Pa, the outlet is set as the ambient pressure with a pressure value of 101325 Pa, and the pressure difference between the two ends is 10000 Pa; the flow field area is meshed, and the mesh is refined for the narrow space; the simulation operation is carried out according to the set conditions to obtain the flow field state;

[0121] As Figures 32 - 35 shown, check the simulation operation results and observe the velocity change in the flow field;

[0122] As Figure 32 shown, three positions are selected respectively to observe the flow state of the flow field, namely the velocity cloud diagrams of the longitudinal section along the flow direction, the longitudinal direction, and the radial section, the velocity cloud diagram of the radial cross-section 85 mm in front of the measuring instrument behind the spoiler blade 5, and the velocity cloud diagram of the radial cross-section 300 mm behind the detection probe 2 in the pressure reduction pipe section 4;

[0123] Figure 33 The velocity cloud diagram of the longitudinal section along the flow direction is highlighted. It can be found from it that the local eddy current in the pressure reduction pipe section 4 is significantly reduced and moves towards the pipe axis region.

[0124] Figure 34 The velocity cloud diagram of the radial cross-section 85 mm in front of the measuring instrument behind the spoiler blade 5 is highlighted. Observing this cloud diagram, it can be found that after the fluid passes through the spoiler blade with an angle of 50°, it generates circumferential rotation. The velocity in the central region is about 62 - 81 m / s, the velocity in the middle layer region is about 81 - 105 m / s, and the velocity in the outer layer region gradually increases from 105 m / s to 119 m / s and then gradually decreases from 119 m / s to 0 m / s; in this state, the maximum velocity of the flow field is approximately located at the position of 7 / 8 of the inner wall radius of the detection pipe section 3 from the center of the circle;

[0125] Figure 35It mainly shows the velocity contour map of the radial cross-section flow field inside the pressure-reducing pipe section 4, 300 mm behind the detection probe 2. By observing this contour map, it can be found that the circumferentially rotating flow field continues to exert a squeezing effect on the local eddy current inside the pressure-reducing pipe section 4, the center point of the backflow moves to the pipe axis region, and the region with a lower flow velocity is pressed to the 9 o'clock direction;

[0126] As Figure 36 shown, the flow state diagram of solid particles in the flow field after injection is obtained by simulation. It can be found from the figure that the solid particles are well mixed before reaching the detection probe 2 after passing through the spoiler vane 5, which can meet the requirements of solid particle detection. However, due to the decrease in the angle of the spoiler vane 5, some solid particles bounce back when hitting the spoiler vane 5;

[0127] Example 7: When the angle between the blade body 5-1 and the radial cross-section of the mixing tube is 30°, the operation of the flow field is analyzed as follows:

[0128] A three-dimensional model with an angle of 30° between the blade body 5-1 and the radial cross-section of the mixing tube is established; the fluid is set as air, the molecular mass is 0.02896 kg / mol, the dynamic viscosity is 1.85×10 -5 Pa·s, the inlet pressure value is 111325 Pa, the outlet is set as the ambient pressure, the pressure value is 101325 Pa, and the pressure difference between the two ends is 10000 Pa; the flow field area is meshed, and the mesh is refined in the narrow space; the simulation operation is carried out according to the set conditions to obtain the flow field state;

[0129] As Figures 37 - 40 shown, view the simulation operation results and observe the velocity change in the flow field;

[0130] As Figure 37 shown, three positions are selected respectively to observe the flow state of the flow field, namely the velocity contour maps of the longitudinal section along the flow direction, the longitudinal direction, and the radial section, the velocity contour map of the radial cross-section flow field 85 mm in front of the measuring instrument behind the spoiler vane 5, and the velocity contour map of the radial cross-section flow field 300 mm behind the detection probe 2 inside the pressure-reducing pipe section 4;

[0131] Figure 38 It mainly shows the velocity contour map of the longitudinal section along the flow direction. It can be found from it that the local eddy current inside the pressure-reducing pipe section 4 is significantly reduced and moves towards the pipe axis region,

[0132] Figure 39Highlights the velocity contour map of the radial cross-section flow field at a position 85 mm in front of the distance measuring instrument and behind the spoiler blade 5. By observing this contour map, it can be found that after the fluid passes through the spoiler blade with an included angle of 30°, circumferential rotation is generated. The velocity in the central region is approximately 36 - 54 m / s, the velocity in the middle layer region is approximately 54 - 95 m / s, and the velocity in the outer layer region gradually increases from 95 m / s to 111 m / s and then gradually decreases from 111 m / s to 0 m / s; in this state, the maximum velocity of the flow field is roughly located at a position of 9 / 10 of the inner wall radius of the detection pipe section 3 from the center of the circle;

[0133] Figure 40 Highlights the velocity contour map of the radial cross-section flow field inside the pressure reduction pipe section 4 at a position 300 mm behind the detection probe 2. By observing this contour map, it can be found that the circumferentially rotating flow field continues to exert a squeezing effect on the local eddy current inside the pressure reduction pipe section 4, and the center point of the backflow moves to the pipe axis region, and the region with a lower flow velocity is pressed to the 9 o'clock direction;

[0134] As Figure 41 shown, the flow state diagram of the solid particles in the flow field after injection is obtained by simulation. It can be found from the figure that the solid particles are already evenly mixed after passing through the spoiler blade 5, which can meet the requirements of solid particle detection. However, due to the decrease in the angle of the spoiler blade 5, a large number of solid particles rebound when hitting the spoiler blade 5;

[0135] Example 8: When the included angle between the blade body 5-1 and the radial cross-section of the mixing tube is 20°, the operation of the flow field is analyzed as follows:

[0136] A three-dimensional model with an included angle of 20° between the blade body 5-1 and the radial cross-section of the mixing tube is established; the fluid is set as air, with a molecular mass of 0.02896 kg / mol and a dynamic viscosity of 1.85×10 -5 Pa·s, the inlet pressure value is 111325 Pa, the outlet is set as the ambient pressure with a pressure value of 101325 Pa, and the pressure difference between the two ends is 10000 Pa; the flow field area is meshed, and the mesh is refined for the narrow space; the simulation operation is carried out according to the set conditions to obtain the flow field state;

[0137] As Figures 42 - 45 shown, check the simulation operation results and observe the velocity change in the flow field;

[0138] As Figure 42 shown, three positions are respectively selected to observe the flow state of the flow field, namely the velocity contour maps along the flow direction, longitudinally, and radially. The velocity contour map of the radial cross-section flow field at a position 85 mm in front of the distance measuring instrument and behind the spoiler blade 5, and the velocity contour map of the radial cross-section flow field inside the pressure reduction pipe section 4 at a position 300 mm behind the detection probe 2;

[0139] Figure 43 Highlights the velocity contour map of the longitudinal section along the flow direction. It can be found that the local eddy current in the pressure-reducing pipe section 4 significantly decreases and moves towards the pipe axis region.

[0140] Figure 44 Highlights the velocity contour map of the radial cross-section flow field at a position 85 mm in front of the distance measuring instrument and behind the spoiler vane 5. Observing this contour map, it can be found that after the fluid passes through the spoiler vane with an included angle of 20°, circumferential rotation is generated. The velocity in the central region is approximately 26 - 43 m / s, the velocity in the middle layer region is approximately 43 - 77 m / s, the velocity in the outer layer region gradually increases from 77 m / s to 103 m / s, and then gradually decreases from 103 m / s to 0 m / s; in this state, the maximum velocity of the flow field is roughly located at a position 9 / 10 of the inner wall radius of the detection pipe section 3 from the center of the circle.

[0141] Figure 45 Highlights the velocity contour map of the radial cross-section flow field inside the pressure-reducing pipe section 4 at a position 300 mm behind the detection probe 2. Observing this contour map, it can be found that the circumferentially rotating flow field continues to exert a squeezing effect on the local eddy current inside the pressure-reducing pipe section 4, and the center point of the backflow moves to the pipe axis region, and the region with a lower flow velocity runs through from the 9 o'clock to the 4 o'clock direction.

[0142] As Figure 46 shown, the flow state map of the solid particles in the flow field after injection is obtained by simulation. It can be found from the figure that the solid particles are already evenly mixed after passing through the spoiler vane 5, which can meet the requirements of solid particle detection. However, due to the decrease in the angle of the spoiler vane 5, a large number of solid particles rebound when hitting the spoiler vane 5.

[0143] Example 9: When the included angle between the blade body 5-1 and the radial cross-section of the mixing tube is 10°, the operation of the flow field is analyzed as follows:

[0144] A three-dimensional model with an included angle of 10° between the blade body 5-1 and the radial cross-section of the mixing tube is established; the fluid is set as air, with a molecular mass of 0.02896 kg / mol and a dynamic viscosity of 1.85×10 -5 Pa·s, the inlet pressure value is 111325 Pa, the outlet is set as the ambient pressure, the pressure value is 101325 Pa, and the pressure difference between the two ends is 10000 Pa; the flow field region is meshed, and the mesh is refined for the narrow space; the simulation operation is carried out according to the set conditions to obtain the flow field state.

[0145] As Figures 47 - 50 shown, view the simulation operation results and observe the velocity change in the flow field.

[0146] As Figure 47As shown in the figure, three positions are selected respectively to observe the flow state of the flow field, namely the velocity contour maps of the flow along the flow direction, longitudinally, and radially. They are the velocity contour map of the radial cross-section of the flow field at a position 85 mm in front of the measuring instrument and behind the spoiler blade 5, and the velocity contour map of the radial cross-section of the flow field 300 mm behind the detection probe 2 inside the pressure-reducing pipe section 4.

[0147] Figure 48 The velocity contour map of the longitudinal section along the flow direction is emphasized. It can be found from it that the local eddy current inside the pressure-reducing pipe section 4 is significantly reduced and moves towards the pipe axis region.

[0148] Figure 49 The velocity contour map of the radial cross-section of the flow field at a position 85 mm in front of the measuring instrument and behind the spoiler blade 5 is emphasized. By observing this contour map, it can be found that after the fluid passes through the spoiler blade with an included angle of 10°, circumferential rotation is generated. The velocity in the central region is about 24 - 41 m / s, the velocity in the middle layer region is about 41 - 69 m / s, and the velocity in the outer layer region gradually increases from 69 m / s to 101 m / s and then gradually decreases from 101 m / s to 0 m / s; in this state, the maximum velocity of the flow field is roughly located at a position 9 / 10 of the inner wall radius of the detection pipe section 3 from the center of the circle.

[0149] Figure 50 The velocity contour map of the radial cross-section of the flow field 300 mm behind the detection probe 2 inside the pressure-reducing pipe section 4 is emphasized. By observing this contour map, it can be found that the circumferentially rotating flow field continues to exert a squeezing effect on the local eddy current inside the pressure-reducing pipe section 4, and the center point of the backflow moves to the pipe axis region, and the region with a lower flow velocity runs from the 9 o'clock direction to the 4 o'clock direction.

[0150] As Figure 51 shown, the flow state diagram of the solid particles in the flow field after injection is obtained by simulation. It can be found from the figure that the solid particles are already evenly mixed after passing through the spoiler blade 5, which can meet the requirements of solid particle detection. However, due to the decrease in the angle of the spoiler blade 5, a large number of solid particles bounce back when hitting the spoiler blade 5.

[0151] Summarizing the simulation results of the above Examples 1 - 9, the flow field state of the fluid before reaching the spoiler blade and the running state of the solid particles before reaching the spoiler blade can be obtained. The specific content is shown in Table 1; Table 1 Spoiler Blade Angle and Flow Field Particle State Table

[0152]

[0153]

[0154] Analysis of the simulation results shows that by adjusting the angle between the spoiler vane 5 and the radial section of the mixing tube 1, the flow field behind the spoiler vane 5 can be changed, causing the fluid to generate circumferential rotation around the pipe axis, thereby playing a role in mixing and stirring the solid particles carried in the flow field.

[0155] In Table 1, the item "Solid particle position" is used to show the position of the solid particles in the longitudinal height when the fluid drives the solid particles to flow between the spoiler vane 4 and the detection probe 2 at different angles, so as to show the mixing state of the solid particles in the flow field before reaching the detection probe 2; in Table 1, the item "Solid particle rebound" is used to show the rebound situation generated when the fluid drives the solid particles to flow to the position of the spoiler vane 4 at different angles, so as to show the obstruction situation of the spoiler vane 4 to the operation of the flow field at different angles.

[0156] In this simulation, when the angle between the spoiler vane 5 and the radial section of the mixing tube 1 is 90°, there is no obvious change in the flow field behind the spoiler vane 5; when the angle is 80°, an obvious circumferential rotation has already been generated in the flow field behind the spoiler vane 5; however, when the angles are 90° and 80°, the flow velocity distribution of the flow field behind the spoiler vane 5 is similar and there is no obvious change, and it fails to produce an effective mixing and stirring effect on the solid particles carried in the fluid. The solid particles are mainly located in the middle and lower layers of the flow field, and the spoiler vane 5 will not produce an obvious obstruction effect on the operation of the solid particles.

[0157] When the angle between the spoiler vane 5 and the radial section of the mixing tube 1 is 70°, an obvious circumferential rotation has already been generated in the flow field behind the spoiler vane 5, and the solid particles have already shown an upward movement trend driven by the flow field. Before reaching the detection probe 2, a large number of solid particles have already moved to the middle layer of the flow field; the flow velocity of the flow field behind the spoiler vane 5 has decreased, indicating that the spoiler vane 5 has already produced an obstruction effect on the flow of the fluid, but it has not caused an obvious blockage to the solid particles carried in the fluid.

[0158] When the angles between the spoiler vane 5 and the radial section of the mixing tube 1 are 60°, 50°, and 40°, the flow field behind the spoiler vane 5 continues to maintain circumferential flow, and the solid particles are evenly mixed before reaching the detection probe 2 driven by the flow field; however, as the angle continues to decrease, the obstruction effect of the spoiler vane 5 on the fluid gradually increases, and the flow velocity of the flow field behind the spoiler vane 5 gradually decreases; at the same time, the rebound of the solid particles generated after hitting the spoiler vane 5 also gradually increases. Only a very small amount of solid particles rebounded at an angle of 60°, a small amount of solid particles rebounded at 50°, and a considerable part of the solid particles had rebounded when it reached 40°.

[0159] When the angle between the spoiler vane 5 and the radial section of the mixing tube 1 is 30°, 20°, or 10°, the flow field behind the spoiler vane 5 still maintains circumferential flow, and the solid particles are evenly mixed before reaching the detection probe 2. However, as the angle continues to decrease, the obstruction of the spoiler vane 5 to the fluid becomes more obvious, seriously affecting the velocity of the flow field. When the angle is 30°, 20°, or 10°, a large number of solid particles rebound after hitting the spoiler vane 5, indirectly indicating that a smaller angle has caused the flow field to malfunction.

[0160] By analyzing the above situation, it can be seen that when the angle between the spoiler vane 5 and the radial section of the mixing tube 1 is 90°, 80°, or 70°, the flow field behind the spoiler vane 5 cannot form an effective stirring effect. Before reaching the detection probe 2, the solid particles are mainly located in the middle and lower layers of the flow field, which cannot meet the usage requirements.

[0161] When the angle between the spoiler vane 5 and the radial section of the mixing tube 1 is 30°, 20°, or 10°, although the solid particles can be evenly mixed before reaching the detection probe 2, the spoiler vane 5 has an obvious obstructive effect on the flow field and cannot meet the usage needs either.

[0162] When the angle between the spoiler vane 5 and the radial section of the mixing tube 1 is 60°, 50°, or 40°, an effective stirring effect can be formed behind the spoiler vane 5, enabling the solid particles to be evenly mixed before reaching the detection probe 2, and it will not seriously affect the operation of the flow field. Therefore, the angle range of 60° to 40° is a reasonable usage range for the spoiler vane 5 and can meet the actual usage needs.

[0163] The present invention not only studies the angle of the spoiler vane and the mixing situation of solid particles in the flow field under given conditions through finite element analysis, provides the optimal angle range of the spoiler vane for the solid particles to be evenly mixed in the flow field, but also provides a research method for obtaining the mixing state of solid particles in the flowing medium. Other researchers can refer to this method to study the mixing state of solid particles in the flow field.

[0164] The above is only a preferred embodiment of the present invention and does not impose any form of limitation on the present invention. Although the present invention has been disclosed above with a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art, without departing from the technical solution scope of the present invention, can make some modifications or equivalents by using the above-disclosed technical content. However, as long as it does not depart from the technical solution content of the present invention and is based on the technical essence of the present invention, any simple modification, equivalent replacement, and improvement of the above embodiments still fall within the protection scope of the technical solution of the present invention.

Claims

1. An optimization method for the angle of the flow disturbance blades in a fluidized particulate pollutant detector. The fluidized particulate pollutant detector includes a mixing tube barrel (1), a detection probe (2), a detection pipe section (3), and a pressure reduction pipe section (4). The mixing tube barrel (1), the detection pipe section (3), and the pressure reduction pipe section (4) are connected in sequence from left to right. The detection probe (2) is installed on the detection pipe section (3), and the flow disturbance blades (5) are installed inside the mixing tube barrel (1). The flow disturbance blades (5) are arranged in a circular array by a plurality of blades. The outer ends of the plurality of blades are evenly arranged and installed on the inner wall of the mixing tube barrel (1). The inner ends of the plurality of blades are concentrated at the axis position of the mixing tube barrel and are close to each other. Each blade is composed of a blade body (5-1) and a blade column (5-2). The blade body (5-1) is a thin sheet structure, and the blade column (5-2) is fixed at one end of the blade body (5-1). The length of each blade is less than the radius of the mixing tube section (1). The aspect ratio of the length to the width of the blade body (5-1) is 3:

1. It is characterized in that The optimization method for the angle of the flow disturbance blades in the fluidized particulate pollutant detector includes the following steps: Step 1, establish a three-dimensional model of the flow field; Step 2, set the angle between the blade body (5-1) and the radial cross-section of the mixing sleeve (1) to multiple different angles; Step 3, set the limiting conditions of the flow field; Step 4, perform grid division on the flow field area and encrypt the network for narrow spaces; Step 5, perform simulation operations to obtain the velocity distribution of the flow field and the mixing state of solid particles at different angles; Step 6, analyze according to the simulation results to obtain the flow field state of the fluid before reaching the flow disturbance blades and the running state of the solid particles before reaching the flow disturbance blades at different flow disturbance blade angles.

2. The optimization method for the angle of the spoiler vane in a fluidized particulate matter detector according to claim 1, wherein In Step 2, the angles between the blade body (5-1) and the radial cross-section of the mixing sleeve (1) are sequentially set to 90°, 80°, 70°, 60°, 50°, 40°, 30°, 20°, and 10°.

3. The optimization method of the spoiler blade angle in a fluidized particulate matter detector according to claim 1, characterized in that In step 3, the limiting conditions of the flow field include that the fluid is air, the molecular mass is 0.02896 kg / mol, the dynamic viscosity is 1.85×10 -5 Pa·s, the absolute pressure value at the inlet is 111325 Pa, the absolute pressure value at the inlet is 111325 Pa, the outlet is set to the ambient pressure, the absolute pressure value is 101325 Pa, and the pressure difference between both ends is 10000 Pa.

4. The optimization method of the spoiler blade angle in a fluidized particulate matter detector according to claim 1, characterized in that, In Step 6, analyze according to the simulation results to determine that the optimal angle range of the flow disturbance blades is 40° to 60° to achieve the uniform distribution of solid particles in front of the detection probe (2).

5. The optimization method of the angle of the spoiler vane in a fluidized particulate matter detector according to claim 4, characterized in that The density of the solid particles is 7800 kg / m 3 , the diameter is 0.0001 m, the injection rate is 0.0001 kg / s, and the initial velocity of the injected particles is 0 m / s.

Images