Laser-sensing-based particle concentration self-adaptive regulation and control device for combustion chamber PIV (particle image velocimetry) test

Abstract

The invention provides a laser-sensing-based particle concentration self-adaptive regulation and control device for combustion chamber PIV test, which comprises an air inlet chamber and a particle storage chamber for storing solid particles, an air outlet interface is arranged at the top end of the air inlet chamber, a plurality of air inlet interfaces which are uniformly distributed in the circumferential direction are arranged on the side wall of the air inlet chamber, and the air inlet interfaces are communicated with the air inlet chamber. A solid particle inlet is formed in the side wall of the air inlet chamber and located below the height where the air inlet connectors are located. The particle storage chamber is located on the side portion of the air inlet chamber, the solid particle inlet is wrapped in the particle storage chamber, a horizontally-arranged feeding screw is arranged in the particle storage chamber, one end of the feeding screw is located in the solid particle inlet, and the other end of the feeding screw extends out of the particle storage chamber and is connected with an adjustable-speed motor. The device has the outstanding performances of wide gas flow regulation and control range, high particle space distribution uniformity and fine concentration regulation.

Description

Technical Field

[0001] This invention relates to the field of laser particle image velocimetry technology, specifically to a particle concentration adaptive control device for combustion chamber PIV testing based on laser sensing. Background Technology

[0002] In current experimental research, significant technical bottlenecks persist in methods for observing flow fields of flames and various airflows. With technological innovation, diversified experimental methods have gradually developed: advancements in laser technology have enabled researchers to achieve high-precision measurements of fluid velocity using planar laser particle image velocimetry (PIV) and to continuously and dynamically capture airflow using visible light / laser imaging techniques. By tracking the trajectories of tracer particles in the flow field, researchers can gain in-depth analysis of the flow regime characteristics. These optical measurement techniques have become core tools in flow field research; however, the problem of uniformly and quantitatively adding tracer particles remains unsolved, becoming a key technical challenge restricting measurement accuracy.

[0003] Current particle seeding technologies used in scientific research have inherent limitations and are costly to produce. Mainstream methods not only require substantial initial investment but also necessitate customized modifications for specific flow field environments, significantly increasing research costs and implementation difficulty, and hindering the efficient advancement of research in related fields to some extent. Summary of the Invention

[0004] To address the technical problems existing in the background art, this invention proposes an adaptive particle concentration control device for combustion chamber PIV testing based on laser sensing.

[0005] This invention proposes a laser-sensor-based adaptive particle concentration control device for combustion chamber PIV testing, comprising: an air inlet chamber and a particle storage chamber for storing solid particles, wherein:

[0006] The top of the air intake chamber is provided with an air outlet, and the side wall of the air intake chamber is provided with multiple circumferentially distributed air intake ports. The side wall of the air intake chamber and below the height of each air intake port is provided with a solid particle inlet.

[0007] The particle storage chamber is located on the side of the air inlet chamber and covers the solid particle inlet inside it. A horizontally arranged feeding screw is provided inside the particle storage chamber. One end of the feeding screw is located inside the solid particle inlet, and the other end extends to the outside of the particle storage chamber and is connected to the speed-regulating motor.

[0008] Preferably, the intake port is equipped with a nozzle at one end inside the intake chamber, with the outlet end facing the bottom of the intake chamber.

[0009] Preferably, the interior of the air intake chamber is a cylindrical cavity, and the top of the air intake chamber is provided with an upper cover; the upper cover is connected to the air intake chamber by a first threaded fastener, and a first sealing gasket is provided at the contact surface between the upper cover and the air intake chamber; the upper cover is a conical cover, and the air outlet is located at the center of the upper cover.

[0010] Preferably, the cross-sectional area of ​​the particle storage chamber decreases sequentially from top to bottom.

[0011] Preferably, the top of the particle storage chamber is provided with a feeding port and an upper cover plate covering the feeding port; the upper cover plate is connected to the particle storage chamber by a second threaded fastener, and a second sealing gasket is provided at the contact surface between the upper cover plate and the particle storage chamber.

[0012] Preferably, the feeding screw is provided with a limit pin and a transmission pin at one end located outside the particle storage chamber. The limit pin is in contact with the outer wall of the particle storage chamber, and the transmission pin is connected to the output shaft of the speed-regulating motor.

[0013] Preferably, a sealing assembly is provided at the junction of the feeding screw and the particle storage chamber.

[0014] Preferably, the sealing assembly includes a first sealing ring, a second sealing ring, a third sealing ring, and a fourth sealing ring arranged along the spacing of the feed screw.

[0015] Preferably, a mounting base is provided on the outer side of the bottom of the air intake chamber, and the mounting base is provided with mounting holes.

[0016] Preferably, it also includes a particle concentration detector for real-time detection of the concentration of solid particles in the air intake chamber and a control component for controlling the speed adjustment motor to increase or decrease its speed based on the concentration detection result.

[0017] Preferably, the particle concentration detector includes a tunable laser and a photodetector, with the tunable laser and photodetector positioned opposite each other on opposite sides of the air inlet chamber.

[0018] In this invention, an outlet port is provided at the top of the inlet chamber, and multiple circumferentially distributed inlet ports and a solid particle inlet located below the inlet ports are provided on the side of the inlet chamber. A particle storage chamber is located on the side of the inlet chamber, and a feeding screw is installed in the particle storage chamber. The feeding screw is connected to a speed-regulating motor. The speed-regulating motor drives the feeding screw to rotate, stably and uniformly pushing the solid particles in the particle storage chamber into the inlet chamber, thereby achieving uniform addition of solid particles into the airflow. This device has outstanding performance characteristics such as a wide gas flow rate control range, high uniformity of particle spatial distribution, and finely adjustable concentration, which can significantly improve particle dispersal efficiency and the reliability of flow field measurement experiments. Furthermore, it is easy to operate, compact in size, simple in structure, and low in manufacturing cost. Attached Figure Description

[0019] Figure 1This is a schematic diagram of the external structure of a laser-sensing-based adaptive particle concentration control device for PIV testing in a combustion chamber, as proposed in this invention.

[0020] Figure 2 This is a schematic diagram of the internal structure of a laser-sensing-based adaptive particle concentration control device for PIV testing in a combustion chamber, as proposed in this invention.

[0021] Figure 3 This is a schematic diagram of the feeding screw in a laser-sensor-based adaptive particle concentration control device for PIV testing in a combustion chamber, as proposed in this invention.

[0022] Figure 4 This is a schematic diagram showing the positional relationship between the tunable laser, photodetector, and intake chamber in a laser-sensing-based adaptive particle concentration control device for combustion chamber PIV testing proposed in this invention. Detailed Implementation

[0023] Reference Figure 1-4 The present invention proposes a laser-sensor-based adaptive particle concentration control device for combustion chamber PIV testing, comprising: an air inlet chamber 1 and a particle storage chamber 3 for storing solid particles, wherein:

[0024] An air outlet 12 is provided at the top of the air inlet chamber 6, and multiple circumferentially distributed air inlets 9 are provided on the side wall of the air inlet chamber 6. A solid particle inlet is provided on the side wall of the air inlet chamber 6 below the height of each air inlet 9. The particle storage chamber 3 is located on the side of the air inlet chamber 6 and covers the solid particle inlet inside it. A horizontally arranged feeding screw 4 is provided in the particle storage chamber 3. One end of the feeding screw 4 is located inside the solid particle inlet, and the other end extends to the outside of the particle storage chamber 3 and is connected to a speed-regulating motor.

[0025] During operation, nano- to micron-sized fine solid particles are pre-stored in the particle storage chamber 3; then, the feed screw driven by the speed-regulating motor rotates to evenly distribute the fine solid particles in the particle storage chamber 3 into the air inlet chamber 6. At the same time, the target gas enters the air inlet chamber 6 through each air inlet port 9 to form a countercurrent flow in the air inlet chamber 6, so as to uniformly mix the gas and solid particles; finally, the target gas mixed with fine solid particles enters the designated equipment through the air outlet port 12.

[0026] In a further embodiment, a nozzle 17 with its outlet facing the bottom of the intake chamber 6 is installed at one end of the intake port 9 located inside the intake chamber 6. The nozzle 17 directs the intake airflow towards the bottom of the intake chamber 6, creating a forced downward flow that forms a convection circulation with the naturally rising airflow at the top, thereby improving the uniformity of solid particle distribution in the gas. This prevents gas from flowing directly from the intake port 9 to the top outlet port 12, ensuring sufficient gas retention and mixing within the chamber. Simultaneously, the airflow from the nozzle 17 directly impacts the bottom of the intake chamber 6, preventing the deposition of incoming solid particles at the bottom of the intake chamber 6.

[0027] In a further embodiment, the interior of the intake chamber 6 is a cylindrical cavity, and an upper cover 11 is provided on the top of the intake chamber 6. The upper cover 11 is connected to the intake chamber 6 by a first threaded fastener 10, and a first sealing gasket 15 is provided at the contact surface between the upper cover 11 and the intake chamber 6. The upper cover 11 is a conical cover, and the air outlet 12 is located at the center of the upper cover 11. This structural design can reduce the dead zone of gas flow, allowing the airflow to converge more smoothly to the top and avoiding local eddies or stagnation. On the other hand, the conical upper cover 11 can evenly distribute the internal gas pressure, reduce local stress concentration, and avoid airflow separation, thereby reducing pressure loss. In addition, the threaded connection allows the upper cover 11 to be quickly disassembled, facilitating the cleaning, maintenance, or replacement of parts inside the intake chamber 6.

[0028] In a further embodiment, the top of the particle storage chamber 3 is provided with a feeding port and an upper cover plate 1 covering the feeding port; the upper cover plate 1 is connected to the particle storage chamber 3 by a second threaded fastener 2, and a second sealing gasket 16 is provided at the contact surface between the upper cover plate 1 and the particle storage chamber 3. By adding an upper cover plate 1 to the top of the particle storage chamber 3, on the one hand, it can prevent the fine solid particles in the particle storage chamber 3 from escaping during feeding, and on the other hand, it can isolate the outside air and moisture, preventing the fine solid particles inside from absorbing moisture and clumping together.

[0029] In a further embodiment, the end of the feeding screw 4 located outside the particle storage chamber 3 is provided with a limiting pin 18 and a transmission pin 19. The limiting pin 18 contacts the outer wall of the particle storage chamber 3 to prevent axial movement of the feeding screw 4, ensuring the axial position of the feeding screw 4 is fixed during feeding and avoiding deviation caused by vibration or pressure changes. The transmission pin 19 is connected to the output shaft of the speed-regulating motor to achieve efficient torque transmission, while simplifying the assembly structure and reducing the risk of wear on transmission components.

[0030] Furthermore, a sealing assembly is provided at the junction of the feeding screw 4 and the particle storage chamber 3. Specifically, the sealing assembly includes a first sealing ring 20, a second sealing ring 21, a third sealing ring 22, and a fourth sealing ring 23 arranged along the spacing of the feeding screw 4. The multiple sealing rings (20-23) form a stepped barrier, which can maintain the sealing performance even if a single ring fails, and the spacing arrangement can distribute the sealing pressure, reduce the wear of a single sealing ring, and extend the overall service life.

[0031] In a further embodiment, a mounting base 5 is provided on the outer side of the bottom of the air intake chamber 6, and the mounting base 5 has mounting holes. The mounting base 5 is used to fix the air intake chamber 6 in place, so that it remains stable during operation.

[0032] Furthermore, the cross-sectional area of ​​the particle storage chamber 3 decreases progressively from top to bottom. The upper part of the particle storage chamber 3 is wider, which facilitates the storage of large amounts of material; the lower part gradually narrows, allowing the material to be naturally compacted under gravity and flow towards the outlet, reducing the risk of flow interruption caused by voids formed due to mutual support of the granular material.

[0033] Furthermore, to ensure that the concentration of mixed fine solid particles in the target gas can be flexibly adjusted as needed, this embodiment also includes a particle concentration detector for real-time detection of the solid particle concentration in the inlet chamber 6 and a control component that controls the speed adjustment motor to increase or decrease its speed based on the detection results of the particle concentration detector. During operation, the particle concentration detector detects the concentration of solid particles in the inlet chamber 6 in real time. The control component acquires the detection data from the particle concentration detector in real time and controls the speed adjustment motor's rotation speed based on the acquired data. Specifically, when the particle concentration detector detects that the concentration of solid particles in the inlet chamber 6 is greater than a threshold, the control component controls the speed adjustment motor to decrease its rotation speed to reduce the amount of solid particles entering. When the particle concentration detector detects that the concentration of solid particles in the inlet chamber 6 is less than the threshold, the control component controls the speed adjustment motor to increase its rotation speed to increase the amount of solid particles entering. This confirms the optimal rotation speed of the feed screw, ensuring that the solid particle concentration in the inlet chamber 6 meets the requirements.

[0034] Specifically, the particle concentration detector includes a tunable laser 8 and a photodetector 14. The tunable laser 8 and the photodetector 14 are positioned opposite each other on either side of the air inlet chamber 6. During operation, the tunable laser 8 is pre-connected to a power source via its power interface 7, and the photodetector 14 is connected to a control unit via its signal interface 13. Specifically, the control unit is a computer or controller. During detection, the tunable laser 8 emits a laser of a specific wavelength, the wavelength of which must match the absorption peak of the target particle. After the laser passes through the particle-containing gas, the photodetector 14 measures the attenuation of the transmitted light intensity and calculates the concentration according to Beer's Law. The calculated concentration is then transmitted to the control unit, which compares the received concentration with a threshold. When the detected concentration is greater than the threshold, the speed-regulating motor is decelerated; when the detected concentration is less than the threshold, the speed-regulating motor is accelerated.

[0035] As can be seen from the above, this invention has outstanding performance characteristics such as a wide range of gas flow rate control, high uniformity of particle spatial distribution, and finely adjustable concentration, which can significantly improve particle seeding efficiency and the reliability of flow field measurement experiments. Furthermore, it is easy to operate, compact in size, simple in structure, and low in manufacturing cost.

[0036] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A particle concentration adaptive control device for PIV testing in a combustion chamber based on laser sensing, characterized in that, include: The air intake chamber (1) and the particle storage chamber (3) for storing solid particles, wherein: The top of the air intake chamber (6) is provided with an air outlet (12), and the side wall of the air intake chamber (6) is provided with multiple circumferentially distributed air intake ports (9). The side wall of the air intake chamber (6) and below the height of each air intake port (9) is provided with a solid particle inlet. The particle storage chamber (3) is located on the side of the air inlet chamber (6) and covers the solid particle inlet inside it. The particle storage chamber (3) is equipped with a horizontally arranged feeding screw (4). One end of the feeding screw (4) is located inside the solid particle inlet, and the other end extends to the outside of the particle storage chamber (3) and is connected to the speed regulating motor.

2. The adaptive particle concentration control device for PIV testing in a combustion chamber based on laser sensing according to claim 1, characterized in that, The air intake port (9) is located inside the air intake chamber (6) and has a nozzle (17) with its outlet end facing the bottom of the air intake chamber (6).

3. The adaptive particle concentration control device for PIV testing in a combustion chamber based on laser sensing according to claim 1, characterized in that, The interior of the air intake chamber (6) is a cylindrical cavity, and the top of the air intake chamber (6) is provided with an upper cover (11); the upper cover (11) is connected to the air intake chamber (6) by a first threaded fastener (10), and a first sealing gasket (15) is provided at the contact surface between the upper cover (11) and the air intake chamber (6); the upper cover (11) is a conical top cover, and the air outlet (12) is located at the center of the upper cover (11).

4. The adaptive particle concentration control device for PIV testing in a combustion chamber based on laser sensing according to claim 1, characterized in that, The cross-sectional area of ​​the particle storage chamber (3) decreases from top to bottom.

5. The adaptive particle concentration control device for PIV testing in a combustion chamber based on laser sensing according to claim 1, characterized in that, The top of the particle storage chamber (3) is provided with a feeding port and an upper cover plate (1) covering the feeding port; the upper cover plate (1) is connected to the particle storage chamber (3) by a second threaded fastener (2), and a second sealing gasket (16) is provided at the contact surface between the upper cover plate (1) and the particle storage chamber (3).

6. The adaptive particle concentration control device for PIV testing in a combustion chamber based on laser sensing according to claim 1, characterized in that, The feeding screw (4) is provided with a limit pin (18) and a transmission pin (19) at one end outside the particle storage chamber (3). The limit pin (18) is in contact with the outer wall of the particle storage chamber (3), and the transmission pin (19) is connected to the output shaft of the speed regulating motor.

7. The adaptive particle concentration control device for PIV testing in a combustion chamber based on laser sensing according to claim 1, characterized in that, A sealing assembly is provided at the junction of the feeding screw (4) and the particle storage chamber (3); preferably, the sealing assembly includes a first sealing ring (20), a second sealing ring (21), a third sealing ring (22) and a fourth sealing ring (23) arranged along the spacing of the feeding screw (4).

8. The adaptive particle concentration control device for PIV testing in a combustion chamber based on laser sensing according to claim 1, characterized in that, The bottom outer side of the air intake chamber (6) is provided with a mounting base (5), and the mounting base (5) is provided with mounting holes.

9. The adaptive particle concentration control device for combustion chamber PIV testing based on laser sensing according to claim 6 further includes a particle concentration detector for real-time detection of solid particle concentration in the intake chamber (6) and a control component for controlling the speed adjustment motor to increase or decrease or rotate according to the concentration detection result.

10. The particle concentration adaptive control device for combustion chamber PIV testing based on laser sensing according to claim 9, wherein the particle concentration detector includes a tunable laser (8) and a photodetector (14), and the tunable laser (8) and the photodetector (14) are arranged opposite to each other on both sides of the intake chamber (6).

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