Micro-bubble generating device for gasoline engine combustion

Abstract

The invention relates to the technical field of gasoline engine combustion, and provides a micro-bubble generation device based on electric field enhancement aiming at the problems of non-uniform bubble size, large device volume, poor integration with a fuel system and the like in gasoline engine application of the existing micro-bubble generation technology. According to the device, a high-voltage electric field is formed through a capillary electrode and an annular electrode, bubbles are split through coulomb repulsive force induced by the electric field, uniform microbubbles with the diameter smaller than or equal to 100 microns are generated, pressure is monitored in real time in cooperation with a piezoelectric film sensor, and miniaturization and deep integration of a fuel system are achieved. Compared with the prior art, mechanical disturbance is not needed, bubble uniformity is improved, the device is small in size and can be directly connected into a gasoline engine fuel system, combustion efficiency is remarkably improved, and pollutant emission is reduced.

Description

Technical Field

[0001] This invention belongs to the field of gas-liquid reaction and gasoline engine combustion technology, specifically relating to a microbubble generation device based on electric field enhancement, which is suitable for gasoline engine fuel systems. It improves combustion efficiency and reduces pollutant emissions by dissolving microbubbles into gasoline. Background Technology

[0002] In traditional gasoline engine technology, the fuel supply system premixes gasoline and air before delivering it to the cylinder, where it is ignited by a spark plug to form a flame propagation combustion. Although premixed combustion has a faster initial reaction rate, incomplete combustion still occurs due to insufficient mixture homogeneity, combustion chamber structure constraints, and physical limitations on flame propagation speed. This incomplete combustion leads to reduced fuel energy utilization, decreased thermal efficiency, and the generation of large amounts of harmful emissions such as carbon monoxide and hydrocarbons, resulting in energy waste and environmental burden.

[0003] Microbubble technology (bubble diameter ≤100μm) has shown significant application potential in the energy and industrial fields due to its unique physicochemical properties. However, current technologies face bottlenecks: The existing microbubble preparation method and apparatus disclosed in CN101837255A uses mechanical stirring or porous membrane aeration to generate microbubbles. It relies on mechanical disturbance, which can easily lead to uneven bubble size. In addition, it requires stirring equipment, and the device is bulky and cannot be integrated into the fuel system of mobile vehicles such as gasoline engines. The existing technology disclosure number CN210710887U is a multi-channel electrostatic enhanced air flotation device that achieves electrostatic dispersion through a multi-channel structure. However, its design is aimed at water treatment air flotation scenarios. The multi-channel structure is prone to clogging, and it does not have pressure monitoring, so it cannot adapt to the high-pressure (0.3~0.5MPa) and high-frequency vibration environment of gasoline engine fuel systems. Existing technologies have not solved the dual challenges of achieving uniform bubble size and miniaturized device integration, which limits the practical application of microbubble technology in gasoline engines.

[0004] Therefore, there is an urgent need for a microbubble generation device that requires no mechanical disturbance, has controllable dimensions, and is compatible with gasoline engine systems. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a microbubble generation device based on electric field enhancement. This device generates tiny, uniform bubbles that can dissolve in gasoline fuel, enhancing gasoline engine combustion efficiency, saving energy, protecting the environment, and reducing harmful smoke emissions. Furthermore, the electric field enhancement technology employed in this invention, by applying an external electric field to regulate the behavior of multiphase flow interfaces, provides an innovative solution to the challenges of existing technologies. This technology utilizes an electric field to induce free charges at the gas-liquid interface, effectively reducing interfacial surface tension through the Coulomb repulsion between charges. When the electric field strength is increased to the kilovolt level, the bubble interface undergoes controllable instability and splitting, efficiently generating uniform, concentrated micron-sized bubble clusters. This mechanism overcomes the limitations of traditional microbubble generation methods in size control, laying a technical foundation for the engineering application of microbubble technology.

[0006] The technical means employed in this invention are as follows: A microbubble generation device based on electric field enhancement includes a bubble conductor, a capillary electrode, a ring electrode, a gas source, a high-voltage power supply, and a piezoelectric thin-film sensor. The bubble conductor is cylindrical with a channel at the bottom, in which the capillary electrode is embedded, and a ring electrode is provided on the inner wall of the top. The capillary electrode is connected to the gas source through a gas supply pipe, which is equipped with a one-way valve. The ring electrode is connected to the negative terminal of the high-voltage power supply, and the capillary electrode is grounded. The piezoelectric thin-film sensor is integrated into the inner wall of the bottom of the bubble conductor for dynamic pressure feedback. A connecting pipe is provided on the top side of the bubble conductor, which is connected to the low-pressure fuel supply pipe of a gasoline engine.

[0007] Furthermore, the capillary electrode is a stainless steel microneedle with a diameter ≤50μm.

[0008] Furthermore, the annular electrode is made of titanium alloy and has a diameter ≤100μm.

[0009] Furthermore, the annular electrode and the capillary electrode are coaxially arranged.

[0010] Furthermore, the high-voltage power supply is a solid-state high-voltage pulse power supply with an output voltage of 5~30kV and a frequency of 1~50kHz, used to form an enhanced electric field between the two electrodes.

[0011] Furthermore, the inner wall of the bubble conductor is coated with insulating varnish, and the outside is provided with a high-performance engineering plastic insulating shell. The inside can contain liquid medium, and the liquid level is lower than that of the connecting pipe.

[0012] Furthermore, the piezoelectric thin-film sensor is made of scandium-solid-solid aluminum nitride, with a frequency response >10kHz, high temperature and high pressure resistance, and real-time monitoring of pressure fluctuations in the discharge region.

[0013] Furthermore, the connecting pipe is made of stainless steel, and its diameter is compatible with the low-pressure fuel line of the gasoline engine. A sealed connection is achieved through a quick connector.

[0014] In this invention, gas supplied by a gas source enters the liquid medium through a capillary electrode, initially forming spherical bubbles. A high-voltage power supply applies an electric field, inducing free charges at the gas-liquid interface. Coulomb repulsion weakens the surface tension, causing the bubbles to deform into a conical shape. When the electric field strength rises to a critical value (≥10kV), the conical bubbles become unstable and split, generating uniform microbubbles with a diameter of 50~100μm. The microbubbles, along with the liquid, enter the gasoline engine fuel system through a connecting pipe. A piezoelectric thin-film sensor provides real-time pressure feedback, ensuring the safe operation of the device.

[0015] Compared with the prior art, the present invention has the following advantages: 1. The microbubble generation process of this invention does not require mechanical disturbance and directly achieves bubble miniaturization through electrical energy drive. This not only significantly increases the specific surface area for gas-liquid mass transfer but also enhances the uniformity of bubble size. This process greatly strengthens the interaction and mass transfer efficiency between the gas and liquid phases.

[0016] 2. This invention achieves miniaturization and integration of the device, eliminating mechanical parts and resulting in a small overall size, allowing direct installation onto gasoline engine fuel lines. The quick-connect fitting design of the connecting pipe solves the incompatibility issue of existing technologies with high-pressure fuel systems, and shortens installation time.

[0017] 3. The device is highly practical. The generation of microbubbles causes pressure fluctuations in the electrode area. The piezoelectric thin film sensor can provide real-time feedback on the dynamic pressure of the discharge area, ensuring the safety of the device and adapting to the vibration environment of gasoline engines. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of the present invention.

[0020] In the diagram: 1. Bubble conductor; 2. Capillary electrode; 3. Ring electrode; 4. Gas source; 5. Gas delivery pipe; 6. One-way valve; 7. High-voltage power supply; 8. Connecting pipe; 9. Piezoelectric thin film sensor. Detailed Implementation

[0021] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0024] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0025] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0026] For ease of description, spatial relative terms such as "above," "over," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation besides the orientation of the device as described in the figures. For example, if the device in the figures is inverted, a device described as "above" or "above" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0027] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0028] like Figure 1 As shown in the figure, this invention discloses a microbubble generation device based on electric field enhancement, including a bubble conductor 1, a capillary electrode 2, a ring electrode 3, a gas source 4, a high-voltage power supply 7, and a piezoelectric thin-film sensor 9. The bubble conductor 1 is cylindrical, with a channel at the bottom, in which the capillary electrode 2 is embedded, and a ring electrode 3 is provided on the inner wall of the top. The capillary electrode 2 is connected to the gas source 4 through a gas supply pipe 5, which is equipped with a one-way valve 6. The ring electrode 3 is connected to the negative terminal of the high-voltage power supply 7, and the capillary electrode 2 is grounded. The piezoelectric thin-film sensor 9 is integrated into the inner wall of the bottom of the bubble conductor 1 for dynamic pressure feedback. A connecting pipe 8 is provided on the top side of the bubble conductor 1, which is connected to the low-pressure fuel supply pipe of a gasoline engine. The piezoelectric thin-film sensor 9 is electrically connected to a controller for real-time monitoring. The one-way valve 6 is provided to prevent backflow of gas in the gas supply pipe. This prevents excessive water pressure at the bottom of the bubble conductor 1 from causing gas backflow, effectively protecting the microbubble generation device.

[0029] Furthermore, the capillary electrode 2 is a stainless steel microneedle with a diameter ≤50μm.

[0030] Furthermore, the annular electrode 3 is made of titanium alloy and has a diameter ≤100μm.

[0031] Furthermore, the annular electrode 3 and the capillary electrode 2 are coaxially arranged.

[0032] Furthermore, the high-voltage power supply 7 is a solid-state high-voltage pulse power supply with an output voltage of 5~30kV and a frequency of 1~50kHz, used to form an enhanced electric field between the two electrodes.

[0033] Furthermore, the inner wall of the bubble conductor 1 is coated with insulating varnish, and the outside is provided with a high-performance engineering plastic insulating shell. The interior can contain a liquid medium, with the liquid level lower than that of the connecting pipe 8. In this embodiment, the liquid medium is deionized water.

[0034] Furthermore, the piezoelectric thin-film sensor 9 is made of scandium-solid-solid aluminum nitride, with a frequency response >10kHz, high temperature and high pressure resistance, and real-time monitoring of pressure fluctuations in the discharge region.

[0035] Furthermore, the connecting pipe 8 is made of stainless steel, and its diameter is compatible with the low-pressure fuel line of the gasoline engine. A sealed connection is achieved through a quick connector.

[0036] Specifically, when gas from the gas source enters the capillary, an electric field is applied. Initially, the gas forms bubbles in the liquid medium at the capillary tip. As the electric field strength increases, the gas at the capillary opening gradually transforms from spherical droplets into conical bubbles. Due to the enhanced electric field, the conical bubbles become unstable and break up, forming microbubble structures. The mechanism is that the electric field induces free charges in the gas-liquid interface region, and the Coulomb repulsion between these charges significantly weakens the interfacial surface tension. When the electric field strength reaches a high level, this weakening of interfacial tension causes the bubbles to split, resulting in a large number of uniformly sized, micron-sized fine bubbles, which then enter the subsequent system of the gasoline engine through the device's connecting pipe.

[0037] By introducing a microbubble generator into the gasoline engine fuel system, the fuel is converted into a gas-liquid mixture containing dissolved microbubbles. When this microbubble-containing fuel mixture is sprayed through the injector to form atomized droplets, the presence of microbubbles significantly enhances the atomization effect: the energy generated by the bursting of bubbles under high pressure further breaks the droplets into finer particles, greatly increasing the contact area between the fuel and air. More importantly, these microbubbles promote the combustion reaction to be initiated simultaneously from multiple points on the outer surface and internal cavities of the droplets, changing the traditional single flame propagation mode. This faster and more complete combustion process effectively improves the combustion efficiency of gasoline engines and significantly reduces the emission of pollutants such as unburned hydrocarbons and carbon monoxide, thus achieving the dual benefits of energy saving and environmental protection.

[0038] When gasoline containing microbubbles is injected under high pressure through the fuel injector, the pressure of the microbubbles drops sharply from 0.3-0.5 MPa to the negative pressure in the combustion chamber. Under this environment, they rapidly expand and burst, and the released kinetic energy further breaks the fuel droplets into fine particles with a diameter of ≤5μm, improving the atomization effect by 3 to 5 times compared to traditional methods. This ultra-fine atomization greatly increases the contact area between fuel and air, providing a physical basis for complete combustion.

[0039] The dissolution of microbubbles in gasoline can reduce fuel viscosity, improve its fluidity, and reduce the risk of fuel injector clogging. At the same time, the charge effect at the bubble interface can promote the activation of fuel molecules, reduce the activation energy of the combustion reaction, make combustion more complete, and reduce the generation of carbon monoxide and unburned hydrocarbons, which meets the technical requirements of gasoline engines for high efficiency and low emissions.

[0040] In practical use, firstly, fix the bubble conductor 1 next to the low-pressure fuel line of the gasoline engine fuel supply system using a bracket, ensuring that the connecting pipe 8 and the low-pressure fuel line are sealed together via a quick connector. Inject gasoline into the bubble conductor 1, ensuring the liquid level is 5-10mm below the inlet of the connecting pipe 8 to prevent liquid from flowing directly into the fuel line. Connect the gas source 4 and adjust the gas supply pressure to 0.1-0.3MPa, ensuring that the gas enters the capillary electrode 2 in one direction only through the one-way valve 6. Turn on the high-voltage power supply 7 and set the output voltage to 10-20kV and the frequency to 10-30kHz. Specifically, adjust according to the gasoline engine displacement: 10kV for small displacement ≤1.6L and 15-20kV for large displacement >1.6L.

[0041] Gas enters the gasoline medium through capillary electrode 2 and splits into microbubbles with a diameter ≤100μm under the action of a high-voltage electric field. The microbubbles, along with the gasoline, enter the low-pressure fuel line of the gasoline engine through connecting pipe 8, mix with the fuel, and are atomized by the fuel injector before entering the combustion chamber. Piezoelectric thin-film sensor 9 provides real-time feedback on pressure fluctuations within the bubble conductor. If the pressure is abnormal, the high-voltage power supply automatically cuts off for protection. After a period of operation, the cleanliness of the electrodes is checked, and surface carbon is removed to maintain the electric field strength.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A micro-bubble generating device for gasoline engine combustion, characterized by, The application relates to a bubble conduction device, which comprises a bubble conduction device (1), a capillary electrode (2), a ring electrode (3), a gas source (4), a high-voltage power supply (7) and a piezoelectric film sensor (9); the bubble conduction device (1) is in a cylindrical shape, is provided with a hole at the bottom, the hole is embedded with the capillary electrode (2), and the inner wall of the top is provided with the ring electrode (3); the capillary electrode (2) is connected with the gas source (4) through a gas conveying pipe (5), the gas conveying pipe (5) is provided with a one-way valve (6); the ring electrode (3) is connected with the negative electrode of the high-voltage power supply (7), and the capillary electrode (2) is grounded; the piezoelectric film sensor (9) is integrated on the inner side wall of the bottom of the bubble conduction device (1) and is used for feeding back dynamic pressure; the top side of the bubble conduction device (1) is provided with a connecting pipe (8) which is connected with a low-pressure oil conveying pipe of a gasoline engine.

2. The apparatus of claim 1, wherein, The capillary electrode (2) is a stainless steel micro needle with a diameter of less than or equal to 50 mu m.

3. The apparatus of claim 1, wherein, The ring electrode (3) is made of titanium alloy and has a diameter of less than or equal to 100 mu m.

4. The apparatus of claim 1, wherein, The ring electrode (3) is coaxially arranged with the capillary electrode (2).

5. The apparatus of claim 1, wherein, The high-voltage power supply (7) is a solid-state high-voltage pulse power supply, has an output voltage of 5-30 kV and a frequency of 1-50 kHz, and is used for forming a reinforced electric field between two electrodes.

6. The apparatus of claim 1, wherein, The inner wall of the bubble conduction device (1) is sprayed with insulating paint, the outer part is provided with a high-performance engineering plastic insulating shell, the inside can accommodate liquid medium, and the liquid surface is lower than the connecting pipe (8).

7. The apparatus of claim 1, wherein, The piezoelectric film sensor (9) is made of scandium solid-solution aluminum nitride, has a frequency response of more than 10 kHz, is resistant to high temperature and high pressure, and can monitor pressure fluctuation of a discharge area in real time.

8. The apparatus of claim 1, wherein, The connecting pipe (8) is made of stainless steel, has a pipe diameter which is matched with the low-pressure oil conveying pipe of the gasoline engine, and is sealed and connected through a quick connector.

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