Internal flow visualization bubble atomization system based on reinforced premixing of static mixer

Abstract

The invention relates to an internal flow visualization bubble atomization system based on enhanced premixing of a static mixer, the internal flow visualization bubble atomization system comprises a visualization premixing box, an LED lamp and a high-speed camera, the visualization premixing box is communicated with a static premixer, an oil tank and a nitrogen cylinder; a static premixer is adopted, a repeated and rotating multi-stage spiral structure in the static premixer is utilized, fluid which can not be fully mixed is sheared, segmented and remixed, vortexes and shearing force are manufactured in the fluid, the fluid is sequentially subjected to layered cutting, rotation direction reversing and three-dimensional space recombination processes, and a multi-scale composite vortex field is formed. Compared with a traditional mechanical stirring or dynamic mixing device, the structure completely depends on the self-organizing characteristic of fluid mechanics to achieve mixing, the problems of energy loss and mechanical abrasion caused by moving parts are avoided, and meanwhile different flow working conditions can be adapted through modular unit combination design.

Description

Technical Field

[0001] This invention relates to the field of atomization technology, specifically to an internal flow visualization bubble atomization system based on static mixer-enhanced premixing. Background Technology

[0002] Two-phase gas-liquid atomization methods are of great significance in improving the atomization and combustion efficiency of liquid fuels. These methods include four common atomization mechanisms: emulsion atomization, flash boiling atomization, cavitation atomization, and bubble atomization. Bubble atomization, in particular, only requires the introduction of a small amount of air at a pressure similar to that of the liquid fuel, thus having lower requirements for the injection pressure of the liquid fuel. Furthermore, its atomization performance is less dependent on the fluid properties of the liquid fuel itself, making it applicable to various working fluids. Compared to flash boiling atomization, which requires auxiliary heating of the liquid phase, and emulsion atomization, which requires the introduction of an immiscible fuel mixture, bubble atomization offers certain advantages. Under the guidance of energy conservation and emission reduction goals, two-phase gas-liquid atomization, represented by bubble atomization, has significant research value and application significance. Current bubble atomization technology struggles to achieve a uniform distribution of bubbles in the premixed mixture and cannot observe the dynamic changes in bubble generation and flow pattern inside the premixing chamber under different gas-liquid ratios and fuel pressures. Existing patents, such as application number CN202211484523.9, utilize a series of Venturi chambers to perform multiple mixing, shearing, foaming, and breaking processes with vertically entering atomizing gas, forming a gas-liquid two-phase flow rich in microbubbles. This enhances the uniformity of gas-liquid two-phase mixing and the density of bubbles during the bubble atomization process, significantly improving the fuel atomization effect.

[0003] However, in some of the aforementioned bubble atomizing nozzles, the gas-liquid mixing efficiency is low due to structural design and other reasons, resulting in uneven bubble distribution in the overall gas-liquid mixture and thus affecting the final atomization performance. The premixing chambers are generally closed, making it impossible to observe the influence of the gas-liquid ratio and aeration hole size on the gas-liquid phase coupling effect, and thus impossible to determine the optimal gas-liquid ratio and related structural dimensions for achieving optimal bubble flow pattern control. Summary of the Invention

[0004] The present invention aims to solve the above-mentioned technical problems by providing an internal flow visualization bubble atomization system based on static mixer enhanced premixing.

[0005] To solve the above-mentioned technical problems, the technical solution provided by the present invention is as follows:

[0006] An internal flow visualization bubble atomization system based on static mixer enhanced premixing includes a visualization premixing box, an LED light and a high-speed camera, wherein the visualization premixing box is connected to a static premixer, an oil tank and a nitrogen cylinder;

[0007] The outlet of the static premixer is equipped with a nozzle, which sprays the gas-liquid mixture onto the area to be tested.

[0008] The LED light illuminates the area to be detected, and the high-speed camera captures the gas-liquid mixture within the area to be detected.

[0009] Preferably, the high-speed camera is electrically connected to a computer.

[0010] Preferably, the front of the visual premix box is fitted with quartz glass and a stainless steel clamping layer, with the quartz glass located between the visual premix box and the stainless steel clamping layer.

[0011] Preferably, the upper end of the visual premixing box is equipped with a premixing chamber air inlet and a premixing chamber oil inlet.

[0012] Preferably, the outlet of the nitrogen cylinder is connected to a Nennis accumulator, the Nennis accumulator is connected to the inlet of the premixing chamber through a gas pipe, and a flow meter is installed on the gas pipe.

[0013] Preferably, the oil tank is connected to the oil inlet of the premixing chamber via an oil pipe, and an oil pump is installed in the oil pipe.

[0014] Preferably, the lower end of the visual premixing box is equipped with a connection port that connects to the static premixer, and a premixing pipe that connects to the connection port is installed inside the visual premixing box, with aeration holes opened on the outside of the premixing pipe.

[0015] Preferably, the static premixer has multiple sets of spiral blades installed inside, with two connected spiral blades arranged alternately.

[0016] With the above structure, the present invention has the following advantages:

[0017] 1. This invention proposes a static premixer that utilizes its internal, repeating, rotating, multi-stage spiral structure to shear, divide, and remix incompletely mixed fluids. It generates eddies and shear forces internally, subjecting the fluids to a series of layered cutting, rotational reversal, and three-dimensional spatial recombination processes, forming a multi-scale composite eddy field. This achieves thorough mixing of the gas-liquid two-phase mixture. Compared to traditional mechanical stirring or dynamic mixing devices, this structure relies entirely on the self-organizing characteristics of fluid mechanics to achieve mixing, avoiding energy loss and mechanical wear problems caused by moving parts. Furthermore, its modular unit design allows it to adapt to different flow conditions. This patent achieves a uniformly distributed gas-liquid two-phase mixture at a lower cost and with a stable mechanical structure, providing atomization effects for liquid fuels.

[0018] 2. A visualized bubble atomization premixing chamber is proposed. Compared with the existing bubble atomization devices, which usually cannot effectively monitor the gas-liquid premixing flow inside the premixing chamber, this patent embeds a high-transmittance observation window in the key area of ​​the premixing chamber and integrates an internal flow visualization module. The matching multi-angle high-speed camera system can simultaneously capture transient phenomena such as bubble nucleation, coalescence and breakup, and interface fluctuations. This enables real-time monitoring of the generation process of gas bubbles in the premixing chamber, the gas-liquid premixing process, and the final flow pattern of the gas-liquid mixture. This helps to establish a joint study between internal flow and external spray characteristics and to clarify the gas-liquid two-phase coupling mechanism in the two-phase internal flow atomization process.

[0019] The above overview is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features of the invention will become readily apparent from the accompanying drawings and the following detailed description. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a system diagram of the present invention;

[0022] Figure 2 This is a schematic diagram showing the connection between the visual premix box and the static premixer of the present invention;

[0023] Figure 3 This is a schematic diagram of the installation of the premixed pipe of the present invention;

[0024] Figure 4 This is a schematic diagram of the installation of the spiral blade of the present invention.

[0025] As shown in the figure: 1. Oil tank; 2. Oil pump; 3. Visual premixing tank; 4. Static premixer; 5. Oil inlet of premixing chamber; 6. Air inlet of premixing chamber; 7. Aeration hole; 8. Premixing pipe; 9. Stainless steel clamping layer; 10. Quartz glass; 11. LED light; 12. High-speed camera; 13. Computer; 14. Connection port; 15. Nitrogen cylinder; 16. Nenburg accumulator; 17. Flow meter; 18. Spiral blade. Detailed Implementation

[0026] The embodiments of this application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0027] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0028] The present invention will now be described in further detail with reference to the full text.

[0029] Combined with appendix Figures 1-4 An internal flow visualization bubble atomization system based on static mixer enhanced premixing includes a visualization premixing box 3, an LED light 11 and a high-speed camera 12. The visualization premixing box 3 is connected to a static premixer 4, an oil tank 1 and a nitrogen cylinder 15.

[0030] The outlet of the static premixer 4 is equipped with a nozzle, which sprays the gas-liquid mixture onto the area to be tested.

[0031] LED light 11 illuminates the area to be tested, and high-speed camera 12 captures the gas-liquid mixture within the area to be tested.

[0032] High-speed camera 12 is electrically connected to computer 13.

[0033] The front of the visual premix box 3 is fitted with a quartz glass 10 and a stainless steel clamping layer 9, with the quartz glass 10 located between the visual premix box 3 and the stainless steel clamping layer 9.

[0034] The upper end of the visual premixing box 3 is equipped with a premixing chamber air inlet 6 and a premixing chamber oil inlet 5.

[0035] The outlet of the nitrogen cylinder 15 is connected to a Nang accumulator 16, which is connected to the premixing chamber inlet 6 via a gas pipe, and a flow meter 17 is installed on the gas pipe.

[0036] The oil tank 1 is connected to the premixing chamber inlet 5 via an oil pipe, and an oil pump 2 is installed in the oil pipe.

[0037] The lower end of the visual premixing box 3 is equipped with a connection port 14 that connects to the static premixer 4. The visual premixing box 3 is equipped with a premixing pipe 8 that connects to the connection port 14. An aeration hole 7 is opened on the outside of the premixing pipe 8.

[0038] The static premixer 4 has multiple sets of spiral blades 18 installed inside, with two connected spiral blades 18 arranged alternately.

[0039] In specific implementation of this invention, such as Figure 2 and Figure 3 As shown, the present invention utilizes a static premixer 4 for secondary premixing to achieve a gas-liquid two-phase mixture with uniform gas phase distribution; the internal flow visualization premixing chamber design, especially the real-time monitoring technology for the generation process of large bubbles in the gas path inside the premixing chamber, the premixing process of various bubbles, and the flow pattern state of the final gas-liquid mixture.

[0040] In practical implementation, the nozzle structure at the outlet of the static premixer 4 can be replaced according to actual conditions. The specific opening size and shape can be used to adjust the macroscopic characteristics of the liquid fuel in the external field, such as the spray cone angle and penetration moment. The bubble atomizing nozzle structure can be flexibly adjusted according to actual needs. Based on the visualization test inside the orifice and the macroscopic characteristics of the external spray, a joint study can be established to optimize the nozzle structure, adjust the orifice distribution strategy, orifice size, and nozzle cone angle, and achieve ideal atomization characteristic control.

[0041] This invention employs a Nitrogen accumulator 16 connected to a nitrogen cylinder 15 at the fuel inlet port of the bubble atomization premixing chamber to provide stable liquid fuel pressure. The fuel pressure control process is as follows: firstly, a pressure reducing valve is installed on the gas cylinder to control the high-pressure nitrogen cylinder 15 to stably output a low-pressure gas source. This output gas source is connected to the gas end of the Nitrogen accumulator 16 via a gas hose and pneumatic connector, thereby ensuring a stable gas source pressure for the pre-injected liquid fuel inside the Nitrogen accumulator 16, providing a stable pressure of liquid fuel for the bubble atomization nozzle.

[0042] The accumulator 16 provides low-pressure liquid fuel through a high-pressure fuel line into the premixing chamber inlet. It undergoes initial premixing with bubbles generated by the aeration holes 7 in the premixing tube within the gas path. After a short period of gas-liquid interaction, the resulting bubble distribution is insufficient for stability and uniformity. If introduced into the bubble atomizing nozzle at this stage, the liquid fuel will not achieve sufficient and efficient atomization, requiring further premixing to achieve a stable and uniform gas-phase distribution. Therefore, a static premixer 4 is introduced at the premixing chamber outlet to perform secondary premixing on the uneven gas-liquid mixture generated after the initial premixing. The secondary premixing process is mainly dominated by the repetitive, rotating multi-stage spiral mechanical unit in the static premixer 4. When the mixture enters the static premixing tube 8, its internal mixing unit divides the fluid. The resulting streams undergo velocity changes and directional displacements within the mixer, introducing velocity gradients and turbulence, making the secondary premixing process more thorough and uniform, ultimately resulting in a uniformly distributed gas-liquid two-phase mixture.

[0043] This invention aims to visualize the premixing process and flow pattern of the gas-liquid mixture in a premixing chamber by designing a visualization premixing chamber 3. This allows for observation of the internal gas-liquid two-phase flow state and clarifies the gas-liquid coupling mechanism during bubble atomization. First, liquid fuel temporarily stored in the fuel tank 1 is pumped into the premixing chamber inlet 5 at a pressure of 8 Bar using an oil pump 2. Simultaneously, the gas source pressure and flow rate are controlled by a flow meter 14 and a pressure reducing valve, allowing the gas to enter the premixing chamber inlet 6 at a pressure of 9 Bar. In the premixing chamber 3, the liquid fuel undergoes preliminary premixing with the external gas. The preliminary premixing effect can be optimized by adjusting the structural dimensions of the aeration holes 7. After passing through the premixing chamber, the two-phase mixture enters the static premixer 4 through a DN32 pressure measuring tube. The mixing unit inside the static premixer divides the fluid. The divided fluid is then remixed after the introduction of velocity gradients and turbulence. This process of division and merging is repeated until the secondary premixing process is complete, resulting in an ideal, uniformly distributed gas-liquid two-phase fluid.

[0044] The present invention and its embodiments have been described above. This description is not restrictive, and the embodiments shown throughout are only one of the embodiments of the present invention. The actual structure is not limited to this. In conclusion, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the present invention, they should all fall within the protection scope of the present invention.

Claims

1. An internal flow visualization bubble atomization system based on static mixer-enhanced premixing, characterized in that, It includes a visual premix box (3), an LED light (11) and a high-speed camera (12), wherein the visual premix box (3) is connected to a static premixer (4), an oil tank (1) and a nitrogen cylinder (15); The outlet of the static premixer (4) is equipped with a nozzle, and the nozzle sprays the gas-liquid mixture onto the area to be tested. The LED light (11) illuminates the area to be detected, and the high-speed camera (12) captures the gas-liquid mixture in the area to be detected.

2. The internal flow visualization bubble atomization system based on static mixer enhanced premixing according to claim 1, characterized in that: The high-speed camera (12) is electrically connected to the computer (13).

3. The internal flow visualization bubble atomization system based on static mixer enhanced premixing according to claim 1, characterized in that: The front of the visual premix box (3) is fitted with a quartz glass (10) and a stainless steel clamping layer (9), with the quartz glass (10) located between the visual premix box (3) and the stainless steel clamping layer (9).

4. The internal flow visualization bubble atomization system based on static mixer enhanced premixing according to claim 1, characterized in that: The upper end of the visual premix box (3) is equipped with a premix chamber air inlet (6) and a premix chamber oil inlet (5).

5. The internal flow visualization bubble atomization system based on static mixer enhanced premixing according to claim 4, characterized in that: The outlet of the nitrogen cylinder (15) is connected to a Nanger accumulator (16), which is connected to the inlet (6) of the premixing chamber via a gas pipe, and a flow meter (17) is installed on the gas pipe.

6. The internal flow visualization bubble atomization system based on static mixer enhanced premixing according to claim 4, characterized in that: The oil tank (1) is connected to the premixing chamber inlet (5) via an oil pipe, and an oil pump (2) is installed in the oil pipe.

7. The internal flow visualization bubble atomization system based on static mixer enhanced premixing according to claim 1, characterized in that: The lower end of the visual premix box (3) is equipped with a connection port (14) that connects to the static premixer (4). The visual premix box (3) is equipped with a premixing pipe (8) that connects to the connection port (14). An aeration hole (7) is opened on the outside of the premixing pipe (8).

8. The internal flow visualization bubble atomization system based on static mixer enhanced premixing according to claim 1, characterized in that: The static premixer (4) has multiple sets of spiral blades (18) installed inside, and the two connected spiral blades (18) are arranged alternately.

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