Device for measuring motion trail of non-spherical particles in gas-solid two-phase flow

Abstract

The utility model discloses a device for measuring the motion trail of non-spherical particles in a gas-solid two-phase flow, which belongs to the technical field of pneumatic measurement and comprises a transparent circular-tube-shaped test tube cavity and an air blower which are communicated through a gas conveying tube on a rack, and a shooting assembly comprising two cameras is arranged on one side of the test tube cavity. Two cameras are used for shooting time sequence images of the non-spherical particles in the gas-solid two-phase flow in the same view field from different angles, so that the positions and directions of the non-spherical particles at different moments are obtained, and the motion trail of the particles is determined. According to the device provided by the utility model, the motion trail of the non-spherical particles in the gas-solid two-phase flow can be obtained on the basis of considering translation and rotation, so that a basis is provided for obtaining related kinetic parameters of the non-spherical particles and judging the motion state; conditions are provided for aerodynamic design when the biomass material particles are subjected to blending combustion in the coal-fired boiler, and good practical value is achieved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of pneumatic measurement technology, specifically relates to a device for measuring the motion trajectory of non-spherical particles in gas-solid two-phase flow. BACKGROUND

[0002] At present, the practice of burning biomass fuel in coal-fired units has become an effective way to reduce greenhouse gas emissions and make rational use of biomass waste.

[0003] In actual use, biomass materials are mostly broken into particles for use. For the particles after the biomass material is broken, especially straw particles, they exhibit a highly non-spherical characteristic, mostly in the form of long cylinders. Due to the specificity of the shape of the particles, the aerodynamic behavior of the biomass particles is significantly different from that of conventional spherical coal particles.

[0004] For traditional spherical particles, their particle dynamics model mostly ignores the complex aerodynamic characteristics brought by the non-spherical particles and ignores the rotation and angle characteristics of the particles, resulting in that the conventional particle dynamics model cannot be effectively applied to the measurement of aerodynamic parameters of non-spherical particles, and cannot accurately simulate the motion trajectory of the particles in the combustion chamber of the coal-fired boiler, thereby cannot effectively predict the combustion behavior of the biomass particles, affecting the design of the biomass particle blending combustion scheme and the boiler parameters, and having great limitations. UTILITY MODEL CONTENTS

[0005] In view of one or more of the above defects or improvement needs of the prior art, the utility model provides a device for measuring the motion trajectory of non-spherical particles in gas-solid two-phase flow, which can accurately collect the motion image of non-spherical particles in gas-solid two-phase flow, and then accurately obtain the motion trajectory of non-spherical particles in gas-solid two-phase flow, providing basis and support for the research on the motion behavior of biomass particles in the combustion chamber of the boiler.

[0006] To achieve the above purpose, the utility model provides a device for measuring the motion trajectory of non-spherical particles in gas-solid two-phase flow, comprising a rack, which further comprises a blower and a test tube cavity arranged on the rack;

[0007] The test tube cavity is a circular tube structure made of transparent material, which is arranged vertically and has an open top, so that the non-spherical particles to be measured can be discharged from the opening into the flow field formed in the test tube cavity;

[0008] The air outlet of the blower is communicated with the bottom of the test tube cavity through a gas conveying pipe for forming an airflow field with a certain flow rate in the test tube cavity; and

[0009] A photographing assembly and a light source assembly are arranged corresponding to the test pipe cavity; the photographing assembly comprises a first camera and a second camera, lenses of the two cameras are horizontally aligned with the middle part of the test pipe cavity respectively, photographing fields of view of the two cameras overlap, and a plurality of mark points falling into the photographing fields of view are arranged in the middle part of the test pipe cavity; the light source assembly is arranged on the side of the test pipe cavity away from the photographing assembly, and is used for providing light for photographing of the photographing assembly.

[0010] As a further improvement of the utility model, a clamping mechanism is arranged on the top of the test pipe cavity, and is used for clamping non-spherical particles to be measured and discharging; and the clamping mechanism is arranged at the center of the opening of the test pipe cavity.

[0011] As a further improvement of the utility model, the light source assembly comprises a first light source and a second light source.

[0012] The first light source is opposite to the side of the test pipe cavity away from the first camera, and a line connecting the center of the first light source with the center of the first camera passes through the center of the test pipe cavity; the second light source is opposite to the side of the test pipe cavity away from the second camera, and a line connecting the center of the second light source with the center of the second camera passes through the center of the test pipe cavity.

[0013] As a further improvement of the utility model, a light shielding plate is further vertically arranged on the side of the light source assembly away from the test pipe cavity.

[0014] As a further improvement of the utility model, a posture adjusting frame is arranged at the bottom of at least one camera, and the posture adjusting frame is used for adjusting the position and pose of the corresponding camera in three-dimensional space, so as to ensure that the photographing field of view of the camera overlaps with the photographing field of view of another camera.

[0015] As a further improvement of the utility model, the gas conveying pipe comprises a first pipe and a second pipe communicated with the flow meter;

[0016] One end of the first pipe away from the flow meter is communicated with the air outlet of the air blower, and one end of the second pipe away from the flow meter is communicated with the bottom of the test pipe cavity.

[0017] As a further improvement of the utility model, the test pipe cavity is made of transparent acrylic material, the thickness of the pipe body is 0.01-0.02m, the outer diameter of the pipe body is 0.10-0.20m, and the height of the pipe body is 1.0-1.5m.

[0018] As a further improvement of the utility model, the photographing field of view is 0.6-0.9m away from the bottom of the test pipe cavity.

[0019] As a further improvement of the utility model, the two cameras are multifunctional high-speed cameras, with an exposure time in the range of 80µs~120µs and a frame rate controlled in the range of 2000~5000 frames / second.

[0020] As a further improvement of the utility model, the marker points are arranged on the outer periphery of the test tube cavity, and the distance between the same pair of marker points is equal within the shooting field of view of the two cameras.

[0021] The above technical features can be combined with each other as long as there is no conflict.

[0022] Overall, compared with the prior art, the above technical scheme conceived by the utility model has the following beneficial effects:

[0023] (1) The device for measuring the motion trajectory of non-spherical particles in gas-solid two-phase flow in the utility model, which comprises a test tube cavity and a blower connected by a gas conveying pipe on a rack, sets the test tube cavity as a circular tube structure, sets a shooting assembly comprising two cameras on one side of the test tube cavity, shoots the images of non-spherical particles under the same field of view from different angles by the two cameras, obtains the time sequence images of non-spherical particles in gas-solid two-phase flow under different angles, obtains the position and direction of non-spherical particles at different times, determines the motion trajectory of the particles, effectively improves the accuracy of the simulation of the motion state of non-spherical particles, provides more accurate aerodynamic basis for the design of biomass particle blending in a coal-fired boiler, and promotes the application of biomass particles.

[0024] (2) The device for measuring the motion trajectory of non-spherical particles in gas-solid two-phase flow in the utility model, which is further improved by optimally setting a clamping mechanism, a light source corresponding to the camera, a light shield, a posture adjusting frame corresponding to the camera, and a flow meter corresponding to the gas conveying pipe, can further ensure the convenience and accuracy of the device, fully meet the measurement needs of the simulation of non-spherical particles in gas-solid two-phase flow, and improve the accuracy and reliability of the measurement of the motion trajectory of non-spherical particles.

[0025] (3) The device for measuring the motion trajectory of non-spherical particles in gas-solid two-phase flow in the utility model has a simple structure and is convenient to use, can simulate the motion process of non-spherical particles in gas-solid two-phase flow, accurately obtains the position and direction of non-spherical particles at different times through the collection of multiple images at different angles, and accurately measures the motion trajectory of non-spherical particles in gas-solid two-phase flow, thereby providing accurate basis for the acquisition of non-spherical particle-related dynamic parameters and the judgment of the motion state, providing conditions for the aerodynamic design of biomass material particles in the blending of coal-fired boilers, and having good practical value and application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0027] Figure 1 is a device structure schematic diagram for measuring the motion trajectory of non-spherical particles in gas-solid two-phase flow in the embodiments of the present application;

[0028] In all the drawings, the same reference signs represent the same technical features, specifically:

[0029] 1, rack; 2, air blower; 3, gas conveying pipe; 301, first pipe; 302, second pipe; 4, flow meter; 5, test tube; 6, clamping mechanism; 7, shooting assembly; 701, first camera; 702, second camera; 703, attitude adjusting frame; 8, light source assembly; 801, first light source; 802, second light source; 803, adjustable support; 9, light shield; 10, mark point. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not to limit the present application. In addition, the technical features involved in each embodiment of the present application described below can be combined with each other as long as there is no conflict.

[0031] In the description of the present application, it should be understood that, unless otherwise explicitly specified and limited, the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0032] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this utility model, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0033] In this utility model, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two components, or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on specific circumstances.

[0034] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0035] Example:

[0036] See also Figure 1 In a preferred embodiment of the present invention, the device for measuring the motion trajectory of non-spherical particles in a gas-solid two-phase flow includes a frame 1, which is preferably a frame structure for providing support for the test mechanism in the device.

[0037] Specifically, the test mechanism in the preferred embodiment includes a blower 2 arranged at one end of the frame 1 and a test tube cavity 5 arranged at the other end of the frame 1. The test tube cavity 5 is arranged vertically, and its bottom is connected to the air outlet of the blower 2 through the air supply pipe 3, and the top of the test tube cavity 5 is opened. Then, through the operation of the blower 2, a gas phase flow with a certain flow rate can be formed in the test tube cavity 5 to meet the test requirements of non-spherical particles.

[0038] Meanwhile, the test tube cavity 5 in the preferred embodiment is made of transparent material, such as transparent acrylic material, and is further preferably in a round tube structure, with a cylindrical cavity formed inside. The round tube structure is provided to prevent the image of the collected particles from being "distorted", i.e. the corners of the real cavity in the image have a certain degree of influence on the shape and movement of the particles, fully ensuring the accuracy of the collection of the particle image.

[0039] In more detail, the tube thickness of the test tube cavity 5 in the preferred embodiment is 0.01-0.02m, the outer diameter of the tube is 0.10-0.20m, and the height of the tube is 1.0-1.5m.

[0040] In actual installation, the bottom of the test tube cavity 5 is preferably connected to the end of the gas conveying pipe 3 through a flange. In the preferred embodiment, a flow meter 4 is provided corresponding to the gas conveying pipe 3 for controlling the flow rate of the gas phase flow formed in the test tube cavity 5.

[0041] Illustratively, corresponding to the provision of the flow meter 4, the gas conveying pipe 3 in the preferred embodiment is provided in a two-section structure, i.e. as shown in Figure 1 , comprising a first pipe 301 connected to the air blower 2 and a second pipe 302 connected to the test tube cavity 5, the ends of the two pipes are preferably connected by a flange, and the flow meter 4 is provided between the two pipes.

[0042] In more detail, the second pipe 302 in the preferred embodiment is provided in a 90° bent form at one end for connecting the test tube cavity 5, to ensure that one end can be connected to the horizontally arranged first pipe 301, and the other end can be connected to the vertically arranged test tube cavity 5.

[0043] Further, the discharging of the non-spherical particles in the test tube cavity 5 can be done manually by hand, or by providing a discharging mechanism.

[0044] Illustratively, in the preferred embodiment shown in Figure 1 , a clamping mechanism 6 is provided at the top of the test tube cavity 5 for clamping the non-spherical particles to be tested at a specific angle before the test begins, such as clamping the non-spherical particles to be discharged in a horizontal state (0°), to ensure that the initial state of the multiple particles is consistent when the test is performed.

[0045] In specific installation, the clamping mechanism 6 can preferably be a commercially available mini clamp, which is further preferably arranged at the center of the test tube cavity 5, to ensure that the particles to be tested can be discharged from the center of the test tube cavity 5.

[0046] More specifically, corresponding to the collection of the image of the motion of the biomass particles in the test tube cavity 5, a shooting assembly 7 is further arranged on one side of the test tube cavity 5, and the shooting assembly 7 in the preferred embodiment comprises a first camera 701 and a second camera 702, and the shooting lenses of the two cameras are respectively directed to the middle position of the test tube cavity 5 from different angles. By shooting the time sequence images of the non-spherical particles in the same field of view from different angles through the two cameras, the real shape of the non-spherical particles in the three-dimensional space can be finally coupled according to the positions and shapes of the particles in the two groups of images, and then the real motion trajectory of the particles considering the translation and rotation can be obtained.

[0047] Meanwhile, the bottom of at least one camera in the preferred embodiment is provided with a posture adjusting frame 703, and the shooting angle and position of the camera can be adjusted through the adjustment of the posture adjusting frame 703, so as to correspondingly adjust the overlapping of the shooting fields of view of the two cameras.

[0048] Of course, the two posture adjusting frames 703 are preferably arranged on a triangular support frame, and the triangular support frame provides reliable support for the two cameras, as shown in Figure 1

[0049] In actual arrangement, the shooting fields of view of the two cameras are preferably overlapped, and the actual measurement interval for collecting the particle images is preferably located at a position 0.6-0.9 m away from the bottom of the test tube cavity 5. The reason for selecting this position interval to collect the particle images is that the particles in the images are closer to the particle state in the real situation after falling a distance since the discharge, and the gas in the cavity at this position can also develop into turbulent flow, effectively avoiding the influence of the possible turbulent motion at the gas inlet on the measurement results.

[0050] Further, a plurality of marker points 10 are arranged on the outer periphery of the test tube cavity 5 corresponding to the shooting fields of view of the two cameras, and all the marker points 10 are ensured to be simultaneously in the shooting fields of view of the two cameras, and the distance between the same pair of marker points 10 is ensured to be equal. At this time, by controlling the two cameras to work synchronously, the particle images of the non-spherical particles in the shooting fields of view at the same motion moment can be correspondingly collected from different field angles, and then two groups of continuously shot particle images can be obtained.

[0051] Exemplarily, the two cameras are preferably multifunctional high-speed cameras, and the maximum frame rate thereof is not less than 2000 frames / second, and the shortest exposure time is not less than 1 µs. More specifically, the exposure time of the two cameras is preferably in the range of 3.9 µs-1 s, and the frame rate of the two cameras is controlled in the range of 0-200000 frames / second.

[0052] ​For example, in a specific preferred embodiment, the two camera models used are Photron-Fastcam Mini UX50, which has a maximum resolution of 1280x1024 and a maximum frame rate of 200000 frames / s, and a minimum exposure time of 3.9μs.

[0053] In actual settings, the exposure time and frame rate are important parameters of the high-speed camera. If the exposure time is too long, it is easy to produce smearing, which affects the experimental results. If the exposure time is too short, the brightness of the collected image is too dark, the contrast between the particles and the background will not be obvious, and the difficulty of image processing will increase. If the frame rate is set too low, the number of images recorded in the measurement area is too small, and the accuracy of the experimental results cannot be guaranteed. If the frame rate is set too high, the number of recorded images is too large, and the workload of image processing will increase. Therefore, in the preferred embodiment, the exposure time of the two cameras is preferably set in the range of 80µs~120µs, and the frame rate of the two cameras is preferably controlled in the range of 2000~5000 frames / s.

[0054] More preferably, in order to make the contrast between the test particles and the test lumen 5 more obvious, a light source assembly 8 is preferably arranged on the side of the test lumen 5 away from the shooting assembly 7, which includes a first light source 801 and a second light source 802 arranged corresponding to the two cameras respectively. Wherein, the two light sources are preferably supported by an adjustable support 803, and the light height of the two light sources is preferably corresponding to the shooting height of the two cameras. The first light source 801 is preferably arranged corresponding to the first camera 701, and the center line of the two passes through the center of the test lumen 5. Correspondingly, the second light source 802 is preferably arranged corresponding to the second camera 702, and the center line of the two also preferably passes through the center of the test lumen 5.

[0055] Further preferably, a light barrier 9 is also vertically arranged on the side of the light source assembly 8 away from the test lumen 5, to reduce the dispersion of the light of each light source in the light source assembly 8, so as to avoid the influence of external light on the shooting of the shooting assembly 7.

[0056] For the device for measuring the motion trajectory of non-spherical particles in gas-solid two-phase flow in the preferred embodiment, the process in actual use is preferably as follows:

[0057] After the assembly of the device is completed, the shooting field of view of the shooting assembly 7 and the light state of the light source assembly 8 are adjusted, and the non-spherical particles to be tested are fixed on the clamping mechanism 6; the air blower 2 is controlled to work, and the gas flow rate in the test cavity 5 is adjusted through the flow meter 4 to form a stable gas phase flow in the test cavity 5; thereafter, the shooting assembly 7 is controlled to work at the set equipment parameters, and the clamping mechanism 6 is controlled to release the material, so that the non-spherical particles enter the gas flow field; after the non-spherical particles enter the shooting field of view of the two cameras, the images of the non-spherical particles in the test cavity 5 are continuously shot by the two cameras, and two groups of test images satisfying the time sequence are obtained; finally, through processing of the two groups of test images, the position and direction of the non-spherical particles at different times can be accurately obtained, and the motion trajectory of the non-spherical particles in the gas-solid two-phase flow is obtained.

[0058] More specifically, for the processing of the two groups of test images in the preferred embodiment, the TEMA software in the prior art can be further preferred to complete, the full name of which is "TEMA advanced motion analysis tool", which is a high-level motion analysis tool developed by Image Systems AB Company in Sweden, which can obtain time sequence data of the shooting object at high speed and high precision based on continuously shot images in three-dimensional space, including position, speed, acceleration, incident angle, angular velocity, angular acceleration and other data information of the object. The processing process of the test image can be quickly completed by using the mature technology in the prior art, which is not the focus of the preferred embodiment, so it is not described here.

[0059] Of course, according to the actual use needs, the processing of the test image can also be completed by using other software in the prior art, as long as the position and direction of the non-biological particles with time can be determined.

[0060] The device for measuring the motion trajectory of the non-spherical particles in the gas-solid two-phase flow in the utility model has the advantages of simple structure, convenient use, can realize the simulation of the motion process of the non-spherical particles in the gas-solid two-phase flow, accurately obtains the position and direction of the non-spherical particles at different times through the acquisition of multiple images at different angles, and accurately measures the motion trajectory of the non-spherical particles in the gas-solid two-phase flow, thereby providing accurate basis for obtaining the related dynamic parameters of the non-spherical particles and judging the motion state, and providing conditions for the aerodynamic design of the biomass material particles when mixed with coal in the coal-fired boiler, and having good practical value and application prospect.

[0061] Those skilled in the art can easily understand that the above description is only a preferred embodiment of the utility model, and is not used to limit the utility model, and any modification, equivalent replacement and improvement made within the spirit and principle of the utility model should be included in the protection scope of the utility model.

Claims

1. A device for measuring the trajectory of non-spherical particles in a gas-solid two-phase flow, comprising a frame, characterized in that, The air blower and the test tube cavity are arranged on the rack; The test tube cavity is a circular tube structure made of transparent material, arranged vertically and open at the top, so that the non-spherical particles to be measured can be discharged from the opening into the flow field formed in the test tube cavity; The air outlet of the air blower is communicated with the bottom of the test tube cavity through the air conveying pipe, for forming an airflow field with a certain flow rate in the test tube cavity; and A shooting assembly and a light source assembly are arranged corresponding to the test tube cavity; the shooting assembly includes a first camera and a second camera, the lenses of the two cameras are respectively horizontally aligned with the middle part of the test tube cavity, the shooting fields of view of the two cameras overlap, and a plurality of marker points falling within the shooting fields of view are arranged in the middle part of the test tube cavity; the light source assembly is arranged on the side of the test tube cavity away from the shooting assembly, for providing illumination for the shooting of the shooting assembly.

2. The device for measuring the trajectory of non-spherical particles in gas- solid two-phase flow according to claim 1, characterized in that, A material clamping mechanism is arranged at the top of the test tube cavity, for clamping and discharging the non-spherical particles to be measured; and the material clamping mechanism is arranged at the center of the opening of the test tube cavity.

3. The device for measuring the trajectory of non-spherical particles in gas- solid two-phase flow according to claim 2, characterized in that, The light source assembly includes a first light source and a second light source; The first light source is opposite to the side of the test tube cavity away from the first camera, and the line connecting the center of the first light source with the center of the first camera passes through the center of the test tube cavity; the second light source is opposite to the side of the test tube cavity away from the second camera, and the line connecting the center of the second light source with the center of the second camera passes through the center of the test tube cavity.

4. The device for measuring the trajectory of non-spherical particles in gas- solid two-phase flow according to claim 3, characterized in that, A light shielding plate is further vertically arranged on the side of the light source assembly away from the test tube cavity.

5. The device for measuring the trajectory of non-spherical particles in gas-solid two-phase flow according to any one of claims 1-4, characterized in that, The bottom of at least one camera is provided with a pose adjusting frame, which is used for adjusting the pose of the corresponding camera in the three-dimensional space, so as to ensure that the shooting field of view of the camera overlaps with the shooting field of view of the other camera.

6. The device for measuring the trajectory of non-spherical particles in gas- solid two-phase flow according to any one of claims 1 to 4, characterized in that, The air conveying pipe includes a first pipe and a second pipe communicated with the flow meter; The end of the first pipe away from the flow meter is communicated with the air outlet of the air blower, and the end of the second pipe away from the flow meter is communicated with the bottom of the test tube cavity.

7. The device for measuring the trajectory of non-spherical particles in gas- solid two-phase flow according to any one of claims 1 to 4, characterized in that, The test tube cavity is made of transparent acrylic material, the thickness of the tube body is 0.01-0.02 m, the outer diameter of the tube body is 0.10-0.20 m, and the height of the tube body is 1.0-1.5 m.

8. The device for measuring the trajectory of non-spherical particles in gas- solid two-phase flow according to claim 7, characterized in that, The shooting field of view is 0.6-0.9 m away from the bottom of the test tube cavity.

9. The device for measuring the trajectory of non-spherical particles in gas- solid two-phase flow according to any one of claims 1 to 4, 8, characterized in that, The two cameras are multifunctional high-speed cameras, the exposure time of which is in the range of 80 µs-120 µs, and the frame rate control is in the range of 2000-5000 frames / second.

10. The device for measuring the trajectory of non-spherical particles in gas- solid two-phase flow according to any one of claims 1 to 4, 8, characterized in that, The marker points are arranged on the outer periphery of the test tube cavity, and the distance between the same pair of marker points is equal within the shooting field of view of the two cameras.

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