Spray droplet separation device, spray visualization test system and use method thereof

Abstract

The present invention discloses a spray droplet separation device, a spray visualization test system, and a method for using the same. The spray droplet separation device includes a height adjustment frame, a support plate horizontally mounted on the height adjustment frame, and two baffles symmetrically arranged on the support plate; a separation gap is formed between the baffles. During experimental testing, the nozzle sprays spray vertically downward, and most of the droplets in the dense spray area impact the baffles. The two baffles intercept most of the droplets in the dense spray area, while a very small portion of the droplets continue to move through the separation gap, thereby reducing the number and concentration of droplets in the dense spray area. This allows optical photography to capture clear droplet images of the dense spray area after separation, allowing those skilled in the art to detect the microscopic behavioral characteristics of droplets in the dense spray center area.

Description

Technical Field

[0001] The present invention relates to the field of fuel injector spray characteristic testing, and in particular to a spray droplet separation device, a spray visualization testing system and a use method thereof. Background Art

[0002] The spray characteristics of the engine injector are one of the important factors affecting the engine performance. The spray characteristics of the injector have a great influence on the engine combustion and emission performance. Therefore, the characteristics of the injector spray characteristics are of great significance to the design and development of the engine combustion system.

[0003] Fuel injector spray utilizes a pressure nozzle to eject fuel from the nozzle at high speed into the ambient air, where it breaks into discrete droplets. Droplet size is a key indicator of atomization quality. However, due to the high injection pressure, the core axis of the spray is dense, making droplets in this dense region difficult to analyze using optical measurement techniques. Consequently, previous research has focused solely on the spray's edge. Because this dense region creates a relative "blind spot" for both laser diagnostics and high-speed photography, investigating the microscopic behavior of droplets from this dense region at the center of the spray has become a research hotspot. Summary of the Invention

[0004] In view of the above-mentioned deficiencies in the prior art, the object of the present invention is to provide a spray droplet separation device, a spray visualization test system and a method of use thereof, aiming to solve the technical problem that clear droplet images cannot be captured due to the high droplet concentration in dense areas.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A spray droplet separation device comprises a height adjustment frame, a support plate horizontally mounted on the height adjustment frame, and two baffles symmetrically arranged on the support plate; the baffles are used to block droplets in a portion of the spray-dense area, and a separation gap is formed between the baffles for droplets in another portion of the spray-dense area to pass through. The size of the separation gap can be adjusted by adjusting the spacing between the two baffles.

[0007] Each of the baffles includes a horizontal bottom plate portion and a raised portion connected to one end of the horizontal bottom plate portion, and the separation gap is formed between the raised portions of the two baffles.

[0008] A waist-shaped hole is provided on the horizontal bottom plate portion of each baffle, and a through hole corresponding to the waist-shaped hole is provided on the support plate. The horizontal bottom plate portion of the baffle is connected to the through hole bolt on the support plate through the waistline hole.

[0009] The height adjustment frame includes a connecting platform, at least two screws vertically passing through the connecting platform, and a positioning column fixed on the screw; a sleeve sleeved on the screw is provided between the positioning column and the connecting platform; the connecting platform is fixed on the screw by a locking assembly.

[0010] The locking assembly includes a plurality of locking screws. A plurality of threaded holes facing the screw rods are opened on the side surface of the connecting platform. The locking screws are screwed into the corresponding threaded holes and press the screw rods.

[0011] In horizontal projection, the positioning column is a polygon.

[0012] The support plate includes a mutually connected strip plate and a C-shaped plate, and the two baffles are installed on the C-shaped plate; a groove for installing the strip plate is opened on the upper surface of the connecting platform, and the strip plate is fixed to the connecting platform by screws.

[0013] The distance between the two baffles is 40-300 μm.

[0014] The present invention also provides a spray visualization test system, comprising the spray droplet separation device, a constant volume bomb body, an injector and a visualization window module arranged on the constant volume bomb body, and a camera installed on the visualization window module, wherein the spray droplet separation device is installed in the internal cavity of the constant volume bomb body.

[0015] The present invention also provides a method for using the spray visualization test system, comprising the following steps:

[0016] S01: According to the set height difference between the injector and the separation gap, a sleeve of appropriate length is selected and sleeved on the screw. The screw passes through the connecting platform from top to bottom, so that the connecting platform presses the sleeve on the positioning column. The connecting platform is then fixed to the screw through the locking assembly. The top end of the screw is threadedly connected to the constant volume bomb body;

[0017] S02: Adjust the distance between the two baffles to change the size of the separation gap, and determine the accuracy of the separation gap by using the baffle in the feeler gauge;

[0018] S03: Adjust the positions of the two baffles so that the axis of the injector is located in the center of the two baffles;

[0019] S04: The camera takes high-speed continuous shots of the injector's spray process; the spray is ejected vertically from the pressure nozzle on the injector. Most of the droplets in the dense spray area are blocked by the baffle, while a small portion of the droplets in the dense spray area pass through the separation gap. The microscopic behavior characteristics of the droplets are recorded under the current separation gap size and the height difference between the injector and the separation gap.

[0020] Beneficial effects:

[0021] The present invention provides a spray droplet separation device, a spray visualization test system, and a method for using the same. The nozzle sprays spray vertically downward, and most of the droplets in the dense spray area hit a baffle. The two baffles intercept the droplets in the dense spray area, and a very small portion of the droplets continue to move through the separation gap, thereby reducing the number and concentration of droplets in the dense spray area. This allows the use of optical photography to capture clear droplet images of the dense spray area after separation, and then analyzes the droplet size and velocity through image post-processing technology, allowing technicians in this field to detect the microscopic behavioral characteristics of droplets in the dense area at the center of the spray. In addition, by quickly and accurately adjusting the size of the separation gap and accurately adjusting the distance between the nozzle and the separation gap, the experimenter can effectively help the experimenter analyze the behavioral patterns of droplets in the vertical free spray after separation. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a three-dimensional diagram of the spray droplet separation device provided by the present invention.

[0023] Figure 2 This is an exploded view of the spray droplet separation device provided by the present invention.

[0024] Figure 3 This is a top view of the spray droplet separation device provided by the present invention.

[0025] Figure 4 This is a diagram showing the working principle of the spray droplet separation device provided by the present invention.

[0026] Figure 5 This is a structural schematic diagram of the spray visualization test system provided by the present invention.

[0027] Explanation of the main component symbols: 1-height adjustment frame, 2-support plate, 3-blocking plate, 4-separation gap, 31-horizontal bottom plate, 32-lifting part, 33-waist-shaped hole, 21-through hole, 11-connecting platform, 12-screw, 13-positioning column, 14-sleeve, 51-locking screw, 52-threaded hole, 22-strip plate, 23-C-shaped plate, 111-groove, 6-constant volume bomb body, 7-injector, 71-nozzle. DETAILED DESCRIPTION

[0028] The present invention provides a spray droplet separation device, a spray visualization testing system, and methods for using the same. To clarify the objectives, technical solutions, and effects of the present invention, the present invention is further described below with reference to the accompanying drawings and examples. It should be understood that the specific examples described herein are intended only to illustrate the present invention and are not intended to limit the scope of protection of the present invention.

[0029] See also Figure 1-3The present invention provides a spray droplet separation device comprising a height-adjustable frame 1, a support plate 2 horizontally mounted on the height-adjustable frame 1, and two baffles 3 symmetrically arranged on the support plate 2; the baffles 3 are used to block droplets in a portion of a spray-dense area, and a separation gap 4 is formed between the baffles 3 for droplets in another portion of the spray-dense area to pass through, and the size of the separation gap 4 can be adjusted by adjusting the distance between the two baffles 3.

[0030] Before the test, the nozzle 71 is pointed vertically downward, and the height of the baffle 3 is adjusted by the height adjustment frame 1 so that the distance between the nozzle 71 and the separation gap 4 meets the set test position. In addition, the spacing between the two baffles 3 is adjusted to adjust the size of the separation gap 4 and control the number of droplets that can pass through the separation gap 4. On the other hand, the nozzle 71 is directly facing the center of the two baffles 3 to ensure that the droplets in the dense spray area are the target of separation. Figure 4 As shown, nozzle 71 sprays spray 8 vertically downward. Most of the droplets in the dense spray area impact with baffles 3. Two baffles 3 intercept the droplets in the dense spray area, while a very small portion of the droplets continue to move through the separation gap 4, thereby reducing the number and concentration of droplets in the dense spray area. This allows optical photography to capture clear images of droplets in the dense spray area after separation, and then analyze the droplet size and velocity through image post-processing technology, allowing technicians in this field to detect the microscopic behavioral characteristics of droplets in the dense spray center. In addition, by quickly and accurately adjusting the size of the separation gap 4 and the precise adjustment of the spacing between nozzle 71 and the separation gap 4, experimenters can effectively analyze the behavior of droplets in vertical free spray after separation.

[0031] It should be noted that the adjustable spacing between the two baffles 3 (i.e., the size of the separation gap 4) is 40-300 μm. Because the maximum size of discrete droplets in the spray is around 50 μm, the width of the separation gap 4 is still wide enough for discrete droplets of different sizes to pass through without causing secondary breakage of the discrete droplets. This effectively helps experimenters analyze the particle size and velocity of discrete droplets. The adjustable spacing between the nozzle 71 and the separation gap 4 is 20-80 mm and can be adjusted according to different experimental requirements. The gap between the nozzle and the separation gap is mainly used to consider the impact of spray penetration on droplet breakage in experimental results.

[0032] In one embodiment, each baffle 3 includes a horizontal bottom portion 31 and a raised portion 32 connected to one end of the horizontal bottom portion 31. The separation gap 4 is formed between the raised portions 32 of the two baffles. With this arrangement, droplets intercepted by the raised portions 32 of the baffle 3 flow along the slope of the raised portions 32 toward the horizontal bottom portion 31, preventing these droplets from flowing back through the separation gap 4 and affecting the experimental results.

[0033] Preferably, each baffle has a waist-shaped hole 33 formed on its horizontal bottom plate portion 31, and the support plate 2 has a through hole 21 corresponding to the waist-shaped hole 33. The horizontal bottom plate portion 31 of the baffle is bolted to the through hole 21 of the support plate 2 via the waistline hole. During actual adjustment, the position of the baffle 3 can be moved laterally to change the size of the separation gap 4 by simply loosening the nut in the bolt. After adjustment, the adjustment is completed by checking with a feeler gauge and re-tightening the nut. This is simple to operate and allows for quick adjustment.

[0034] Preferably, the height adjustment frame 1 includes a connecting platform 11, at least two screws 12 vertically passing through the connecting platform 11, and a positioning column 13 fixed on the screw 12; the top surface of the positioning column 13 is lower than the top surface of the screw 12, and a sleeve 14 sleeved on the screw 12 is provided between the positioning column 13 and the connecting platform 11; the connecting platform 11 is fixed to the screw 12 by a locking assembly. During assembly, the top end of the screw 12 is threadedly connected to the inner cavity of the constant volume spring, and the sleeve 14 and the connecting platform 11 are sequentially sleeved on the screw 12 from bottom to top, so that the top surface of the connecting platform 11 presses the sleeve 14 against the bottom surface of the positioning column 13, and then the connecting platform 11 is fixed to the screw 12 by the locking assembly.

[0035] Preferably, the locking assembly includes several locking screws 51. Several threaded holes 52 facing the screw 12 are formed on the side of the connecting platform 11. The locking screws 51 are screwed into the corresponding threaded holes 52 and tighten the screw 12. By loosening the locking screws 51, the connecting platform 11 can be removed and replaced with a sleeve 14 of the appropriate length, thereby precisely adjusting the distance between the nozzle 71 and the separation gap 4.

[0036] In horizontal projection, the positioning column 13 is a polygon; in this embodiment, the positioning column 13 is a hexagonal prism, so that the positioning column 13 has a hand-tightening function, which makes it easy for experimenters to install the screw 12 on the constant volume bomb.

[0037] Preferably, the support plate 2 includes a strip plate 22 and a C-shaped plate 23 connected to each other; the strip plate 22 and the C-shaped plate 23 are integrally formed so that the support plate 2 is a fork-shaped plate, and the two baffles 3 are respectively installed on a support arm of the C-shaped plate 23 by bolts. The baffle 3 is reliably fixed and stable in use, ensuring that the maximum injection pressure that the baffle 3 can withstand is 100 MPa; in addition, the C-shaped plate 23 has an avoidance port for dripping liquid to pass through, the horizontal bottom plate portion 31 is installed at the bottom of the support plate 2, and the raised portion 32 is arranged in the avoidance port 24, so that the horizontal plane where the separation gap 4 is located is flush with the plane of the support plate 2, which is convenient for calculating and determining the distance between the nozzle 71 and the separation gap 4.

[0038] Furthermore, a groove 111 is provided on the upper surface of the connecting platform 11 for installing the strip plate 22. The strip plate 22 is fixed to the connecting platform 11 by screws, so that the upper surface of the support plate 2 is flush with the upper surface of the connecting platform 11, which further facilitates the calculation and determination of the distance between the nozzle 71 and the separation gap 4.

[0039] On the other hand, the present invention also provides a spray visualization test system, such as Figure 5 As shown, it includes the above-mentioned spray droplet separation device, a constant volume bomb body 6, an injector 7 provided on the constant volume bomb body 6, a visualization window module (not shown in the figure), and a camera (not shown in the figure) installed on the visualization window module. The spray droplet separation device is installed in the internal cavity of the constant volume bomb body 6. The constant volume bomb body 6 is cylindrical, and vertically intersecting mounting openings are provided in the constant volume bomb body 6 along three axial directions to form an internal cavity 61. The injector 7 is installed on the mounting opening in the middle. The visualization window module includes quartz glass. The camera is preferably a digital SLR camera.

[0040] Furthermore, the present invention also provides a method for using the above-mentioned spray visualization test system: S01: According to the set distance between the injector 7 and the separation gap 4, a sleeve 14 of appropriate length is selected and sleeved on the screw 12, and the screw 12 passes through the connecting platform from top to bottom, so that the connecting platform presses the sleeve 14 on the positioning column 13, and then the connecting platform 11 is fixed to the screw 12 through the locking assembly, and the top end of the screw 12 is threadedly connected to the constant volume bomb body 6;

[0041] S02: Adjust the distance between the two baffles 3 to change the size of the separation gap 4, and determine the accuracy of the size of the separation gap 4 by using the baffle in the feeler gauge;

[0042] S03: By adjusting the positions of the two baffles 3, the axis of the injector 7 is located in the center of the two baffles 3;

[0043] S04: The camera takes high-speed continuous shots of the spraying process of the injector 7; the spray is ejected vertically from the pressure nozzle 71 on the injector 7, and most of the droplets in the dense spray area are blocked by the baffle 3. A small part of the droplets in the dense spray area passes through the separation gap 4. The microscopic behavior characteristics of the droplets are recorded at the current size of the separation gap 4 and the distance between the injector 7 and the separation gap 4.

[0044] By replacing the sleeve 14 with different lengths, the experimenters can change the distance between the injector 7 and the separation gap 4. By adjusting the distance between the two baffles 3, the size of the separation gap 4 can be quickly and accurately changed; thus, the behavior of droplets in vertical free spray at different positions can be observed.

[0045] It is understandable that those skilled in the art can make equivalent substitutions or changes based on the technical solution and inventive concept of the present invention, and all such changes or substitutions should fall within the scope of protection of the present invention.

Claims

1. A spray droplet separation device, characterized in that: It comprises a height adjustment frame, a support plate horizontally mounted on the height adjustment frame, and two baffles symmetrically arranged on the support plate; the baffles are used to block droplets in a part of the spray-dense area, and a separation gap is formed between the baffles for the droplets in the other part of the spray-dense area to pass through, and the size of the separation gap can be adjusted by adjusting the spacing between the two baffles; each of the baffles comprises a horizontal bottom plate portion and a raised portion connected to one end of the horizontal bottom plate portion, and the separation gap is formed between the raised portions of the two baffles; a waist-shaped hole is provided on the horizontal bottom plate portion of each of the baffles, and a waist-shaped hole is provided on the support plate. The horizontal bottom plate portion of the baffle is connected to the through-hole bolt on the support plate through the waistline hole corresponding to the through-hole; the height adjustment frame includes a connecting platform, at least two screws vertically passing through the connecting platform, and a positioning column fixed on the screw; a sleeve is provided between the positioning column and the connecting platform and is sleeved on the screw; the connecting platform is fixed to the screw by a locking assembly; the locking assembly includes a plurality of locking screws, and a plurality of threaded holes facing the screws are opened on the side of the connecting platform, and the locking screws are screwed into the corresponding threaded holes and press the screws; in horizontal projection, the positioning column is a polygon; The support plate includes a strip plate and a C-shaped plate connected to each other, and the two baffles are installed on the C-shaped plate; a groove for installing the strip plate is opened on the upper surface of the connecting platform, and the strip plate is fixed to the connecting platform by screws; the spacing between the two baffles is 40-300μm.

2. A spray visualization test system, characterized in that: It includes the spray droplet separation device according to claim 1, a constant volume bomb body, an injector and a visualization window module arranged on the constant volume bomb body, and a camera installed on the visualization window module, wherein the spray droplet separation device is installed in the internal cavity of the constant volume bomb body.

3. A method for using the spray visualization test system according to claim 2, characterized in that: The following steps are involved: S01: According to the set height difference between the injector and the separation gap, a sleeve of appropriate length is selected and sleeved on the screw. The screw passes through the connecting platform from top to bottom, so that the connecting platform presses the sleeve on the positioning column. The connecting platform is then fixed to the screw through the locking assembly. The top end of the screw is threadedly connected to the constant volume bomb body; S02: Adjust the distance between the two baffles to change the size of the separation gap, and determine the accuracy of the separation gap by using the baffle in the feeler gauge; S03: Adjust the positions of the two baffles so that the axis of the injector is located in the center of the two baffles; S04: The camera takes high-speed continuous shots of the injector's spray process; the spray is ejected vertically from the pressure nozzle on the injector. Most of the droplets in the dense spray area are blocked by the baffle, while a small portion of the droplets in the dense spray area pass through the separation gap. The microscopic behavior characteristics of the droplets are recorded under the current separation gap size and the height difference between the injector and the separation gap.

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