Method and device for preparing nanometer bubble fuel oil in gas station

Abstract

The invention discloses a method and a device for preparing nanometer bubble fuel oil in a gas station, the device can be integrated in a fuel oil storage tank of the gas station and comprises four systems, namely a gas phase management system, a liquid phase circulation system, an oil feeding and discharging system and a monitoring system; the liquid phase circulating system comprises a circulating oil pumping port, a circulating oil returning port and an external nano bubble fuel oil generating unit; the method comprises the steps that nitrogen is introduced through the gas phase management system, the liquid phase circulation system is started to extract fuel oil from the circulation oil extraction port, the fuel oil is conveyed to the external nanometer bubble generation unit, and the nanometer bubble fuel oil obtained through treatment is injected back to the fuel oil storage tank through the circulation oil return port; at the moment, the fuel oil in the fuel oil storage tank can be directly injected into the fuel oil vehicle after continuous operation. The invention provides a complete solution for realizing large-scale preparation of the nano bubble fuel oil in a terminal scene of a gas station storage tank for the first time, realizes in-situ, continuous and large-scale treatment of the fuel oil, and improves the characteristics of the fuel oil.

Description

Technical Field

[0001] This invention belongs to the field of petrochemical and gas station facilities technology, specifically, it relates to a method and apparatus for preparing nanobubble fuel for gas stations. Background Technology

[0002] Fuel (including gasoline and diesel) plays a crucial role in the global energy consumption structure, especially in the transportation sector. Gas stations, as the primary fuel supply terminals, bear the important responsibility of refueling various motor vehicles. However, with the global energy structure transformation and increasingly stringent environmental regulations, traditional refined oil terminals are facing a triple pressure of "carbon reduction, emission reduction, and efficiency improvement." The following pain points are commonly found in the terminal storage, transportation, and refueling stages of fuel products: After fuel enters the engine, the small surface area of ​​macroscopic fuel droplets leads to slow diffusion combustion and incomplete combustion. Most of the fuel energy is not effectively converted into mechanical energy but is lost as heat; simultaneously, incomplete combustion produces large amounts of harmful gases and particulate matter, harming the environment and human health.

[0003] Nanobubbles have a very large specific surface area, which can significantly increase the contact area with liquids. This means that after introducing nanobubbles into fuel, the interaction between the bubbles and the fuel is more complete, which helps to improve the atomization effect and combustion efficiency of the fuel. CN 217582332 U discloses an oxygen-enriched micro / nanobubble fuel supply control system for automobile engines. After air is pressurized, oxygen is selectively permeated into oxygen-enriched gas in the gas separation device of the oxygen-enriched micro / nanobubble fuel generation system. This oxygen-enriched gas is then mixed with fuel in the micro / nanobubble generator to initially form oxygen-enriched micro / nanobubble fuel, thereby optimizing the combustion process of the engine. It can be seen that although nanobubble fuel technology has been proven to effectively improve combustion efficiency, its application is mostly limited to laboratory or small-scale vehicle-mounted devices, making it difficult to achieve large-scale, low-cost, and continuous production and supply. Obviously, gas stations, as the final link in the fuel supply chain, are the most ideal place to realize the large-scale application of nanobubble fuel. Introducing nanobubbles into the gas station scenario is expected to achieve a synergistic effect of "physical oxygenation + micro-explosion secondary atomization". CN 201434378 Y discloses a nanobubble liquid fuel injection device, which consists of a spray gun, a throttle valve, a control valve, a booster pump, a nanobubble generator, a delivery pump, a fuel tank, and a delivery pipe. The main feature is that the nanobubble generator is connected in series in the delivery pipe. However, this device can only be used in fuel injection systems and is difficult to apply to the continuous production of nanobubble fuel in underground storage tanks of gas stations. It can be seen that there is currently no mature technology that can safely and efficiently integrate the nanobubble preparation system into the existing fuel storage tanks of gas stations.

[0004] Therefore, there is an urgent need to develop a method and apparatus for preparing nanobubble fuel for gas stations, so that it can be directly integrated into underground storage tanks of gas stations and can achieve continuous large-scale production and supply of nanobubble fuel. Summary of the Invention

[0005] The purpose of this invention is to overcome the deficiencies in the prior art and provide a device and method for producing nanobubble fuel at gas stations, which enables in-situ, continuous, and large-scale processing of fuel and improves fuel characteristics.

[0006] The objective of this invention can be achieved through the following technical solutions: The present invention provides a device for preparing nanobubble fuel for gas stations. The device is integrated into the fuel storage tank of the gas station and includes four systems: a gas phase management system, a liquid phase circulation system, an oil inlet and outlet system, and a monitoring system. The gas phase management system includes a gas passage and a gas recovery pipeline; The liquid-phase circulation system includes a circulating oil extraction port and a circulating oil return port integrated into the fuel tank, and an external nanobubble fuel generation unit located outside the fuel tank and connected to the circulating oil extraction port and the circulating oil return port; the external nanobubble fuel generation unit is connected to the gas passage. The fuel inlet and outlet system includes a fresh fuel inlet and a fuel outlet integrated into the fuel storage tank; the fuel outlet is connected to the fuel nozzle. The monitoring system includes a level gauge integrated inside the fuel tank and a pressure control system located outside the fuel tank.

[0007] In some embodiments of the present invention, the circulating oil return port is designed in a distributed manner, with multiple circulating oil outlets distributed on the entire circulating oil return port.

[0008] In some embodiments of the present invention, the external nanobubble fuel generation unit is any one of the nanobubble fuel generation devices based on an oleophobic fiber reactor, a venturi tube-oleophobic fiber reactor, a swirl-release-particle bed reactor, or a nanoporous sintered metal mesh reactor.

[0009] In some embodiments of the present invention, when the external nanobubble fuel generation unit is a nanobubble fuel generation device based on an oleophobic fiber reactor, the device includes a dissolved gas unit and a nanobubble generation reactor; the dissolved gas unit includes a pressurizing pump and a gas mixer; the nanobubble generation reactor is filled with an oleophobic fiber module, the liquid inlet of the nanobubble generation reactor is located on one side of the oleophobic fiber module and connected to the outlet of the dissolved gas unit, and the liquid outlet of the nanobubble generation reactor is located at the bottom of the other side of the oleophobic fiber module for outputting nanobubble fuel; the oleophobic fiber module is a fiber bed formed by disordered stacking of superoleophobic fibers.

[0010] Furthermore, the surface of the superoleophobic fiber has a micro-nano composite structure, comprising micron-sized cavities with diameters ranging from 0.25 μm to 5 μm and nano-sized cavities with diameters ranging from 10 nm to 200 nm. The superoleophobic fiber exhibits a contact angle greater than 150° with water and a contact angle greater than 130° with the standard test oil hexadecane. Preferably, the diameter ratio of the micron-sized cavities to the nano-sized cavities is (10-50):1. The superoleophobic fiber is a fluorinated polymer fiber, and the fiber thickness of the fiber bed formed by the disordered stacking of the superoleophobic fibers is 50 mm to 200 mm, with a packing density of 0.15 g / cm³. 3 ~0.35g / cm 3 .

[0011] In some embodiments of the present invention, when the external nanobubble fuel generation unit is a nanobubble fuel generation device based on a Venturi tube-oleophobic fiber reactor, the device includes a Venturi tube, a nanobubble generation reactor, and a large bubble separator; the Venturi tube includes a constriction section, a throat, and an expansion section connected in sequence, and a gas intake port is provided at the throat of the Venturi tube; the nanobubble generation reactor is filled with an oleophobic fiber module, the liquid inlet of the nanobubble generation reactor is located on one side of the oleophobic fiber module and is connected to the outlet of the expansion section of the Venturi tube, and the liquid outlet of the nanobubble generation reactor is located at the bottom of the other side of the oleophobic fiber module for outputting nanobubble fuel; the oleophobic fiber module is a fiber bed formed by disordered stacking of superoleophobic fibers; the large bubble separator is located above the nanobubble generation reactor and has an exhaust port at the top.

[0012] Furthermore, a negative pressure of not less than -0.05 MPa is generated at the throat of the venturi tube; in some embodiments of the present invention, the large bubble separator is configured to allow bubbles with a particle size greater than 200 nm to float and be discharged through the exhaust port; the surface of the superoleophobic fiber has a micro-nano composite structure, comprising micron-sized cavities with a diameter of 0.25 μm to 5 μm and nano-sized cavities with a diameter of 10 nm to 200 nm, and the superoleophobic fiber has a contact angle greater than 150° with water and a contact angle greater than 130° with the standard test oil hexadecane; preferably, the diameter ratio of the micron-sized cavity to the nano-sized cavity is (10-50):1; the fiber thickness of the fiber bed is 50 mm to 200 mm, and the packing density is 0.15 g / cm³. 3 ~0.35g / cm 3 .

[0013] In some embodiments of the present invention, when the external nanobubble fuel generation unit is a nanobubble fuel generation device based on a swirling gas release-particle bed reactor, the device includes a swirling generator and a particle bed inside it; the upper end of the shell wall of the swirling generator is provided with a tangential liquid inlet, and the top and bottom of the shell are respectively provided with an exhaust outlet and a liquid outlet; a top particle filter and a bottom particle filter are provided inside the shell of the swirling generator below the tangential liquid inlet; the particle bed is contained in the area enclosed by the side wall of the swirling generator shell, the top particle filter and the bottom particle filter, and this area is filled with at least two different sizes of oleophobic particles at a volume filling rate of 50%-70% to form the particle bed.

[0014] Furthermore, the oleophobic particles of the two different particle sizes have a particle size of 3-10 mm for the larger oleophobic particles and 1-4 mm for the smaller oleophobic particles; the particle size ratio of the larger to the smaller oleophobic particles is (1.5-5):1; preferably, the mass ratio of the larger to the smaller oleophobic particles is (10-200):1; the material of the oleophobic particles is any one or more of 304 stainless steel, 316L stainless steel, and 321 stainless steel; the tangential flow velocity of the liquid entering the tangential liquid inlet is 10-30 m / s; the ratio of the height H1 between the top and bottom particle filters to the height H of the cyclone generator is (1 / 3-2 / 3):1; the height-to-diameter ratio H / D of the cyclone generator is (2-5):1.

[0015] In some embodiments of the present invention, when the external nanobubble fuel generation unit is a nanobubble fuel generation device based on a nanoporous sintered metal mesh reactor, the device includes a vertical tank and an internal nanoporous sintered metal mesh. The structure of the nanoporous sintered metal mesh includes a support layer, a transition layer, and a foaming layer arranged sequentially from the inside out. The support layer includes a functional section and a welding neck section in the axial direction, with the welding neck section of the support layer located above the functional section. A tangential circulating oil inlet is provided on the upper side wall of one side of the vertical tank, a nanobubble fuel outlet is provided at the bottom, and a gas inlet pipe is connected to the top. One end of the inlet pipe is located outside the vertical tank body and is used to connect to the external gas passage. The other end extends vertically downward into the interior of the vertical tank body and connects to the welded neck of the support layer. The outer end of the gas inlet pipe is machined into a pipe opening with precise dimensions. The welded neck of the support layer and the pipe opening at the outer end of the gas inlet pipe are connected by a circumferential weld, thereby fixing the nano-metal sintered mesh in the vertical tank body in a suspended manner. A circular sealing plate is welded to the bottom of the nano-metal sintered mesh for sealing the bottom of the gas phase passage, thereby allowing nanobubbles to precipitate from the side of the nano-metal sintered mesh and fully contact the fuel.

[0016] Furthermore, the tangential liquid flow velocity at the circulating oil inlet is 1.5–4 m / s; the nanoporous sintered metal mesh is made of any one or more of 316L stainless steel, titanium, and molybdenum-titanium alloy.

[0017] Furthermore, the nano-metal sintered mesh is prepared using a powder metallurgy process, including the following steps: I. Preparation and Classification of Metal Powders Using air classifier or vibrating sieving technology, the spherical and / or near-spherical powders of the metal material (316L stainless steel, titanium or molybdenum-titanium alloy) are strictly divided into three grades according to particle size: the first grade powder for the support layer has a D50 of 45μm to 75μm; the second grade powder for the transition layer has a D50 of 8μm to 25μm; and the third grade powder for the foaming layer has a D50 of 10nm to 100nm. II. Mold Preparation and Gradient Filling of Metal Powder To better block different grades of metal powder, a specially made cylindrical mold is used. This mold is a three-layer composite core mold, composed of multiple concentric cylindrical components of different diameters (including the inner core mold with the smallest diameter, the middle core mold with the middle diameter and outside the inner core mold, and the outer core mold with the largest diameter and outside the middle core mold). The diameter of the inner core mold corresponds to the diameter of the gas inlet pipe, and the difference in diameter between the other core molds depends on the loose filling thickness of the different layers. The depth of the mold cavity is sufficient to accommodate the functional section of the support layer and the welding neck section. The gradient powder loading and compaction steps are carried out in sequence from the inside to the outside to form a radial gradient structure with the support layer inside, the transition layer in the middle, and the foaming layer outside. The specific steps are: (1) Place the assembled core mold into the cylindrical mold. At this time, fill the annular cavity between the inner core mold and the middle core mold with the first-grade powder and compact it (support layer); (2) Remove the middle core mold, fill the second-level powder between the outer wall of the compacted support layer powder and the inner wall of the outer core mold and compact it (transition layer); (3) Remove the outer core mold, fill the third-level powder between the outer wall of the compacted transition layer powder and the inner wall of the cylindrical mold and compact it (foaming layer); (4) Finally remove the inner core mold to obtain a three-layer gradient green body with a clear interlayer interface; wherein, the loose filling height of the welding neck section of the support layer is 15-25 mm, the height of the functional section of the support layer corresponds to the subsequent transition layer and foaming layer area, and the loose filling height of the functional section is 3 / 5-4 / 5 of the height of the vertical tank, the loose filling thickness of the support layer is 2.0-3.5 mm; the loose filling thickness of the transition layer is 1.2-2.2 mm, and the loose filling thickness of the foaming layer is 0.5-1.0 mm.

[0018] III. Static pressing and sintering densification After the mold with the gradient powder filling is sealed, it is placed in a cold isostatic press and a pressure of 150-250 MPa is applied and held for 2-5 minutes. Then it is transferred to a sintering furnace for high-temperature sintering to obtain a nano-metal sintered mesh. Specifically, for 316L stainless steel: under a vacuum degree better than 1×10⁻⁶... -2 Under the condition of Pa, heat to 1200-1300 °C and hold for 60-120 min; for titanium or molybdenum-titanium alloy, heat to 1300-1400 °C (titanium) or 1500-1700 °C (molybdenum-titanium alloy) under an argon protective atmosphere and hold for 90-180 min; wherein, the pore size of the support layer of the obtained nano-metal sintered mesh is 20 μm-50 μm, the pore size of the transition layer is 5 μm-20 μm, and the pore size of the foamed layer is 0.5 nm-10 nm.

[0019] In some embodiments of the present invention, the pressure control system includes a pressure sensor and several valves to maintain a slight positive pressure of 0.5 kPa to 5 kPa inside the fuel tank; wherein the pressure sensor is disposed on the top wall of the fuel tank; the valves include a first valve disposed on the gas recovery pipeline, a second valve disposed on the pipeline connecting the circulating oil return port and the external nanobubble fuel generation unit, a third valve disposed on the pipeline between the gas passage and the gas recovery pipeline, and a fourth valve disposed on the pipeline connecting the gas passage and the external nanobubble fuel generation unit.

[0020] Another aspect of the present invention provides a method for preparing nanobubble fuel for gas stations, comprising the following steps: (1) Nitrogen gas is introduced into the external nanobubble fuel generation unit through the gas passage in the gas phase management system, the liquid phase circulation system is started, fuel is drawn from the circulating oil extraction port and transported to the external nanobubble fuel generation unit, and the nanobubble fuel obtained after processing is injected back into the fuel storage tank through the circulating oil outlet on the circulating oil return port; at this time, the fuel in the fuel storage tank is continuously operated and then transported to the fuel nozzle through the fuel output port and directly added to the fuel vehicle. (2) Monitor the liquid level of the fuel tank through the liquid level gauge and replenish the fuel tank through the fresh oil inlet; at the same time, discharge the gas on the top of the fuel tank through the gas recovery pipeline according to the pressure control system and maintain a slight positive pressure inside the tank to ensure the safety of the gas station system.

[0021] In some embodiments of the present invention, the flow rate of fuel oil drawn from the circulating oil extraction port per hour in the liquid phase circulation system is 1 / 20 to 1 / 5 of the fuel oil storage tank volume.

[0022] In some embodiments of the present invention, the concentration of nanobubbles in the treated nanobubble fuel is 5 × 10⁻⁶. 7 ~5×108 The number of nanobubbles per mL is <200 nm.

[0023] Compared with the prior art, the present invention has the following outstanding advantages: This invention presents for the first time a complete solution for the large-scale preparation of nanobubble fuel in the end-user scenario of gas station storage tanks. On the one hand, nitrogen inerting ensures safety; on the other hand, cyclic processing achieves homogenization and continuous optimization of fuel quality within the tank. This enables in-situ, continuous, and large-scale fuel processing, allowing vehicles to obtain energy-saving and pollution-reducing nanobubble fuel simply by refueling, without any additional operations. It has extremely low barriers to entry and significant social and economic value. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of an external nanobubble fuel generation unit based on an oleophobic fiber reactor; Figure 2 This is a schematic diagram of an external nanobubble fuel generation unit based on a Venturi tube-oleophobic fiber reactor. Figure 3 This is a schematic diagram of an external nanobubble fuel generation unit based on a swirl-release-particle bed reactor; Figure 4 This is a schematic diagram of an external nanobubble fuel generation unit based on a nanoporous sintered metal mesh reactor. Figure 5 A schematic diagram of a nanobubble fuel preparation device for a gas station; Figure 6 This is an enlarged schematic diagram of the circulating oil return port device.

[0025] Drawing number explanation: 10 - Dissolved gas unit; 20 - Nanobubble fuel generation reactor; 201 - Superoleophobic fiber; 202 - Nanobubble; 203 - Liquid outlet; 204 - Oleophobic fiber module; 30 - Large bubble separator; 40 - Venturi tube; 201 - Superoleophobic fiber; 203 - Liquid outlet; 204 - Oleophobic fiber module; 205 - Nanobubbles with particle size > 200nm; 206 - Nanobubbles with particle size ≤ 200nm; 301 - Exhaust port; 401 - Contraction section; 402 - Throat; 403 - Expansion section; 404 - Gas intake port; 50-Swirl generator; 60-Particle bed; 501-Tangential liquid inlet; 502-Exhaust outlet; 503-Liquid outlet; 504-Swirl column; 505-Top particle filter; 506-Bottom particle filter; 601-Oleophobic particles of different sizes; 70 - Vertical tank body; 71 - Circulating oil inlet; 72 - Gas inlet; 73 - Nanobubble fuel oil outlet; 74 - Nanoporous sintered metal mesh; 75 - Sealing plate; 741 - Support layer; 742 - Transition layer; 743 - Foaming layer; 7411 - Welded neck section; 7412 - Functional section; 100-Fuel oil storage tank; 1-Gas passage; 2-Gas recovery pipeline; 3-Fresh oil inlet; 4-Circulating oil return port; 5-Circulating oil extraction port; 6-Fuel oil outlet; 7-External nano-bubble fuel oil generation reactor; 8-Pressure sensor; 9-Level gauge; 11-First valve; 12-Level; 13-Second valve; 14-Third valve; 15-Fourth valve; 405-Circulating oil outlet; Note: Figure 5 The external nanobubble fuel generation unit 7 in the middle is... Figure 1-4 Any of the devices in it. Detailed Implementation

[0026] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0027] It should be noted that the function of the large bubble separator described in this invention is to actively separate and discharge bubbles with a particle size significantly larger than 200nm. Its design goal is to optimize and improve the particle size distribution of the final nanobubble fuel, rather than to ensure that the particle size of all bubbles is below 200nm.

[0028] The particle size distribution of nanobubbles in the final product (such as D50 and D90) is a comprehensive performance indicator that depends on both the bubble generation and separation processes. The performance of the bubble generation unit (such as the particle bed) determines the initial bubble distribution, while the role of the large bubble separator is to post-process this distribution by removing the coarse ends (high D90 value) to "purify" the product and prevent large bubbles from being mixed in.

[0029] Therefore, even when the large bubble separator is working effectively, if the initial particle size of the bubbles generated by the bubble generation unit is too large, the D50 value of the final product may still be close to or slightly higher than 200 nm. However, compared with a system without this separator, its D90 value will be significantly reduced, the particle size distribution will be more concentrated, and the stability and consistency of the product will be fundamentally improved.

[0030] This invention continuously introduces inert nitrogen gas into a nanobubble generation reactor through a gas passage, and draws fuel from the circulating oil extraction port to an external nanobubble fuel generation unit. The processed nanobubble fuel is then returned to the fuel storage tank through the circulating oil return port. Simultaneously, the device uses a monitoring system to regulate fuel capacity and system safety. After continuous operation, fuel in the storage tank can be delivered to the refueling nozzle through the fuel output port for direct dispensing to fuel-powered vehicles, significantly improving fuel quality. This invention is the first to directly integrate a nanobubble fuel preparation system into the fuel storage tank of a gas station, achieving in-situ, continuous, and large-scale fuel processing, and simply realizing energy conservation and emission reduction for fuel-powered vehicles.

[0031] Example 1 This embodiment describes a device for an external nanobubble fuel generation unit based on an oleophobic fiber reactor. For example... Figure 1 As shown, the device includes a dissolved gas unit 10 and a nanobubble generating reactor 20; the dissolved gas unit includes a known pressurization pump (not shown) and a gas mixer (not shown); the gas mixer is a static mixer; the nanobubble generating reactor 20 is filled with an oleophobic fiber module 204, the inlet of the nanobubble generating reactor 20 is located on one side of the oleophobic fiber module 204 and connected to the outlet of the dissolved gas unit 10, and the fuel outlet 203 of the nanobubble generating reactor 20 is located at the bottom of the other side of the oleophobic fiber module 204 for outputting nanobubble fuel; the oleophobic fiber module 204 is a fiber formed by the disordered stacking of superoleophobic fibers 201. The fiber bed consists of a superoleophobic fiber 201 with a micro-nano composite structure, comprising micron-sized cavities with diameters ranging from 0.25 μm to 5 μm and nano-sized cavities with diameters ranging from 10 nm to 200 nm. The superoleophobic fiber 201 has a contact angle greater than 150° with water and a contact angle greater than 130° with the standard test oil hexadecane. The superoleophobic fiber 201 is preferably a fluorinated polymer fiber, obtained by impregnating conventional polypropylene with Scotchgard™ series fluorinating agents from 3M Company. The fiber thickness of the fiber bed formed by the disordered stacking of the superoleophobic fiber 201 is 50 mm to 200 mm, and the packing density is 0.15 g / cm³. 3 ~0.35g / cm 3 .

[0032] The method for preparing nanobubble fuel using this external nanobubble fuel generation unit is as follows: S1. The gas is dissolved in fuel oil under an operating pressure of 0.3MPa to 0.8MPa through the gas dissolving unit 10, so that the saturation solubility of the gas is >70%, and a liquid with pre-dissolved gas is prepared. S2. The pre-dissolved gas liquid is passed through the inlet of the nanobubble generating reactor 20 at a flow rate of 0.5 m / s to 2.5 m / s through the oleophobic fiber module 204. The dissolved gas is precipitated at the micro-nano composite structure interface of the superoleophobic fiber 201 and forms nanobubbles 202. The nanobubbles flow out from the liquid outlet 203 of the nanobubble generating reactor along with the fuel. The outflowing liquid is collected to obtain nanobubble fuel.

[0033] Example 2 This embodiment describes a device for an external nanobubble fuel generation unit based on a Venturi tube-oleophobic fiber reactor. For example... Figure 2 As shown, the device includes a nanobubble generating reactor 20, a large bubble separator 30, and a venturi tube 40. The venturi tube includes a converging section 401, a throat 402, and an expanding section 403 connected in sequence. A gas intake port 404 is provided at the throat 402 of the venturi tube. The nanobubble generating reactor 20 is filled with an oleophobic fiber module 204. The liquid inlet of the nanobubble generating reactor 20 is located on one side of the oleophobic fiber module 204 and is connected to the outlet of the expanding section 403 of the venturi tube 40. The liquid outlet 203 of the nanobubble generating reactor 20 is located at the bottom of the other side of the oleophobic fiber module 204 and is used to output nanobubble fuel. The oleophobic fiber module 204 is made of superoleophobic fiber. The superoleophobic fiber 201 is formed by disordered stacking of fibers. The surface of the superoleophobic fiber 201 has a micro-nano composite structure, comprising micron-sized cavities with diameters ranging from 0.25 μm to 5 μm and nano-sized cavities with diameters ranging from 10 nm to 200 nm. The superoleophobic fiber 201 has a contact angle greater than 150° with water and a contact angle greater than 130° with the standard test oil hexadecane. The superoleophobic fiber 201 is preferably a fluorinated polymer fiber, obtained by impregnating conventional polypropylene with Scotchgard™ series fluorinating agents from 3M Company. The fiber thickness of the disordered stacked fiber bed is 50 mm to 200 mm, and the packing density is 0.15 g / cm³. 3 ~0.35g / cm 3 The large bubble separator 30 is positioned above the nanobubble generating reactor 20 and has an exhaust port 301 at the top.

[0034] The method for preparing nanobubble fuel using this external nanobubble fuel generation unit is as follows: Fuel is flowed through a venturi tube 40 at a flow rate of 10 m / s to 30 m / s. At the throat 402, the high-speed flow generates a negative pressure, which draws in gas through the gas inlet 404, forming a pre-dissolved gas liquid. The pre-dissolved gas liquid enters the nanobubble generating reactor 20 through the liquid inlet and flows through the oleophobic fiber module 204. The dissolved gas or fine gas is precipitated at the micro-nano composite structure interface of the superoleophobic fiber 201 and forms nanobubbles. Large-sized (D>200nm) micro-nanobubbles 205 are precipitated and enter the large bubble separator 30 above, and are discharged through the exhaust port 301 at the top. Small-sized (D≤200nm) nanobubbles 202 exist stably in the liquid and flow out with the fuel from the liquid outlet 203 of the nanobubble generating reactor. The outflowing liquid is collected to obtain nanobubble fuel.

[0035] Example 3 This embodiment describes a device for an external nanobubble fuel generation unit based on a swirling gas release-particulate bed reactor. For example... Figure 3 As shown, the device includes a cyclone generator 50 and a particle bed 60 inside it; the height-to-diameter ratio H / D of the cyclone generator is (2-5):1; the upper end of the shell sidewall of the cyclone generator 50 is provided with a tangential liquid inlet 501, and the top and bottom of the shell are respectively provided with an exhaust outlet 502 and a liquid outlet 503; inside the shell of the cyclone generator 50, below the tangential liquid inlet 501, there are a top particle filter 505 and a bottom particle filter 506; the particle bed 60 is contained in the area enclosed by the shell wall of the cyclone generator 50, the top particle filter 505, and the bottom particle filter 506, and this area is filled with a volumetric filling rate of 50%-70%. The particle bed 60 is formed by at least two types of oleophobic particles 601 with different particle sizes; the particle size of the large oleophobic particles 601 is 3-10 mm, and the particle size of the small oleophobic particles is 1-4 mm, and the particle size ratio of the large oleophobic particles to the small oleophobic particles is (1.5-5):1; the mass ratio of the large oleophobic particles to the small oleophobic particles is (10-200):1; the material of the oleophobic particles is any one of 304 stainless steel, 316L stainless steel, and 321 stainless steel, preferably 304 stainless steel; the ratio of the height H1 between the top particle filter screen 105 and the bottom particle filter screen 106 to the height H of the cyclone generator 10 is (1 / 3-2 / 3):1.

[0036] The method for preparing nanobubble fuel using this external nanobubble fuel generation unit is as follows: Pre-dissolved fuel oil (gas saturation not less than 70%) is injected into the cyclone generator 50 through the tangential liquid inlet 501 at a flow rate of 10-30 m / s, forming a high-speed cyclone gas column 504. The low-pressure environment at the center of the cyclone causes the dissolved gas to rapidly precipitate and undergo cavitation, generating a large number of microbubbles. These microbubbles, together with the fuel oil, form a gas-liquid mixture that flows into the particle bed 60. Under the strong cyclone field and centrifugal force, the oleophobic particles 601 of different sizes are in a semi-fluidized state within the region and exhibit a dynamic spatial gradient distribution dominated by centrifugal force, i.e., the particle concentration increases from the center of the cyclone towards the generator wall. The shearing force increases significantly, thus forming a dynamic particle-dense region near the vessel wall where the shearing action is particularly intense. As the gas-liquid mixture flows through this dynamically ordered particle bed, the bubbles are subjected to continuous, intense, and efficient impacts and friction between particles and between particles and the vessel wall, resulting in shearing and refinement into nanoscale particles, forming nanobubbles. During this process, large bubbles that do not meet the requirements precipitate out and pass through the top particle filter 505, and then exit from the exhaust outlet 502, while the nanoscale particles that meet the requirements pass through the bottom particle filter 506 along with the fuel and flow out from the liquid outlet 503, thus obtaining nanobubble fuel.

[0037] Example 4 This embodiment describes a device for an external nanobubble fuel generation unit based on a nanoporous sintered metal mesh reactor. For example... Figure 4 As shown, the device includes a vertical tank 70 and a nanoporous sintered metal mesh 74 inside it. The structure of the nanoporous sintered metal mesh 74 includes a support layer 741, a transition layer 742, and a foaming layer 743 arranged sequentially from the inside to the outside. The support layer 741 includes a welded neck section 7411 and a functional section 7412 in the axial direction, with the welded neck section 7411 located above the functional section 7412. A tangential circulating oil inlet 71 is provided above one side wall of the vertical tank 70. A nanobubble fuel oil outlet 73 is provided at the bottom. A gas inlet pipe 72 is connected to the top. One end of the gas inlet pipe 72 is located outside the vertical tank 70 and is used to connect to... One end connects to the external gas passage, while the other end extends vertically downwards into the interior of the vertical tank 70 and connects to the welded neck 7411 of the support layer 741. The outer end of the gas inlet pipe 72 is machined into a pipe opening with precise dimensions. The welded neck 7411 of the support layer 741 and the pipe opening at the outer end of the gas inlet pipe 72 are connected by a circumferential weld, thereby fixing the nanoporous sintered metal mesh 74 in a suspended manner in the vertical tank 70. A circular sealing plate 75 is welded to the bottom of the nanoporous sintered metal mesh 74 for sealing the bottom of the gas phase passage, so that nanobubbles can only be released from the side of the nanoporous sintered metal mesh 74 and fully contact the fuel.

[0038] Furthermore, the tangential liquid flow velocity of the circulating oil inlet 71 is 1.5 to 4 m / s; the material of the nanoporous sintered metal mesh 74 is any one or more of 316L stainless steel, titanium, and molybdenum-titanium alloy; the preferred material is molybdenum-titanium alloy.

[0039] Furthermore, the nanoporous sintered metal mesh 74 is prepared by powder metallurgy, including the following steps: I. Preparation and Classification of Metal Powders Using airflow classification technology, the spherical and / or near-spherical powders of the molybdenum-titanium alloy are strictly divided into three grades according to their particle size: the first grade powder for the support layer 741 has a D50 of 45μm to 75μm; the second grade powder for the transition layer 742 has a D50 of 8μm to 25μm; and the third grade powder for the foaming layer 743 has a D50 of 10nm to 100nm. II. Mold Preparation and Gradient Filling of Metal Powder To better isolate metal powders of different grades, a specially designed cylindrical mold is used. This mold is a three-layer composite core mold, composed of multiple concentric cylindrical components of different diameters (including an inner core mold with the smallest diameter, a middle core mold with a central diameter that fits outside the inner core mold, and an outer core mold with the largest diameter that fits outside the middle core mold). The diameter of the inner core mold corresponds to the diameter of the gas inlet pipe 72, and the difference in diameter between each of the other core molds depends on the loose filling thickness of each layer; and the mold... The cavity depth is sufficient to accommodate the functional segment 7412 of the support layer 741 and the welding neck segment 7411; the gradient powder loading and compaction steps are carried out sequentially from the inside to the outside to form a radial gradient structure with the support layer 741 inside, the transition layer 742 in the middle, and the foaming layer 743 on the outside. The specific steps are: (1) Place the assembled core mold into the cylindrical mold, and at this time, fill the annular cavity between the inner core mold and the middle core mold with the first-level powder and compact it (support layer 741); (2) Remove the middle core mold, fill the second-level powder between the outer wall of the compacted support layer powder and the inner wall of the outer core mold and compact it (transition layer 742); (3) Remove the outer core mold, fill the third-level powder between the outer wall of the compacted transition layer powder and the inner wall of the cylindrical mold and compact it (foaming layer 743); (4) Finally remove the inner core mold to obtain a three-layer gradient green body with a clear interlayer interface; wherein, the loose filling height of the welding neck section 7411 of the support layer 741 is 15-25 mm, the height of the functional section 7412 of the support layer 741 corresponds to the area of ​​the subsequent transition layer 742 and foaming layer 743, and the loose filling height of the functional section 7412 is 3 / 5 to 4 / 5 of the height of the vertical tank 70, the loose filling thickness of the support layer 741 is 2.0-3.5 mm; the loose filling thickness of the transition layer 742 is 1.2-2.2 mm. The loose filling thickness of the foam layer 743 is 0.5 to 1.0 mm.

[0040] III. Static pressing and sintering densification The obtained three-layer gradient green compact was placed in a cold isostatic press and subjected to a pressure of 150–250 MPa for 2–5 min; then transferred to a sintering furnace for high-temperature sintering to obtain a nanoporous sintered metal mesh 74; specifically, for 316L stainless steel: under a vacuum degree better than 1×10 -2 Under the condition of Pa, heat to 1200-1300 °C and hold for 60-120 min; for titanium or molybdenum-titanium alloy, heat to 1300-1400 °C (titanium) or 1500-1700 °C (molybdenum-titanium alloy) under an argon protective atmosphere and hold for 90-180 min; wherein, the pore size of the support layer 741 of the obtained nanoporous sintered metal mesh 74 is 20 μm-50 μm, the pore size of the transition layer 742 is 5 μm-20 μm, and the pore size of the foamed layer 743 is 0.5 nm-10 nm.

[0041] The method for preparing nanobubble fuel using this external nanobubble fuel generation unit is as follows: Fuel is transported to the external nanobubble fuel generation unit through the circulating oil inlet 71 at a tangential flow rate of 1.5 to 4 m / s. Nitrogen is continuously introduced through the gas inlet pipe 72. Under pressure, the nitrogen is forced to precipitate from the sides of the nanoporous sintered metal mesh 74 on its cylindrical surface. When the nitrogen passes through the outermost nanoscale foaming layer 743 of the nanoporous sintered metal mesh 74, the fuel that is circulated and washed by the nanoporous sintered metal mesh 74 is further sheared into a large number of nanobubbles, which flow out from the nanobubble fuel outlet 73 along with the fuel, thus obtaining nanobubble fuel.

[0042] Application Example 1 1.1 Preparation apparatus for nanobubble fuel at gas stations This application example is from a 30m gas station. 3 The device for an externally integrated nanobubble fuel generation unit based on an oleophobic fiber reactor, as described in Example 1 of the 92# gasoline underground fuel storage tank integration. Figure 5 As shown, the preparation device is integrated into the fuel storage tank 100 of the gas station and includes four systems: a gas phase management system, a liquid phase circulation system, an oil inlet and outlet system, and a monitoring system, as detailed below: The gas phase management system includes a gas passage 1 and a gas recovery pipeline 2; The liquid-phase circulation system includes a circulating oil extraction port 5 and a circulating oil return port 4 integrated within the fuel storage tank 100, and an external nanobubble fuel generation unit 7 located outside the fuel storage tank 100 and connected to the circulating oil extraction port 5 and the circulating oil return port 4; the gas passage 1 is connected to the external nanobubble fuel generation unit 7; combined with Figure 6 As shown, the circulating oil return port 4 is a distributed design, with multiple circulating oil outlets 405 distributed on the entire circulating oil return port; wherein, the external nanobubble fuel generation unit is a nanobubble fuel generation device based on an oleophobic fiber reactor. The fuel inlet and outlet system includes a fresh fuel inlet 3 and a fuel outlet 6 integrated within the fuel storage tank 100; the fuel outlet 6 is connected to a refueling nozzle (not shown in the figure); the monitoring system includes a level gauge 9 integrated within the fuel storage tank 100 and a pressure control system located outside the fuel storage tank 100; the pressure control system includes a pressure sensor 8 and several valves, wherein the pressure sensor 8 is installed on the top wall of the fuel storage tank 100; the valves include a first valve 11 installed on the gas recovery pipeline 2, a second valve 13 installed on the pipeline connecting the circulating oil return port 4 and the external nanobubble fuel generation unit 7, a third valve 14 installed on the pipeline between the gas passage 1 and the gas recovery pipeline 2, and a fourth valve 15 installed on the pipeline connecting the gas passage 1 and the external nanobubble fuel generation unit 7; wherein the gas used in the gas passage 1 is nitrogen, or other inert gases well known to those skilled in the art may also be used.

[0043] 1.2 Preparation method of nanobubble fuel for gas stations Using the preparation apparatus described in 1.1 above, the method for preparing nanobubble fuel for gas stations includes the following steps: (1) Nitrogen gas is introduced into the external nanobubble fuel generation unit 7 through the gas passage 1 in the gas phase management system, the liquid phase circulation system is started, and fuel is added to the external nanobubble fuel generation unit 7 through the circulating oil extraction port 5. The nanobubble fuel obtained after processing is injected back into the fuel storage tank 100 through the circulating oil outlet 405 on the circulating oil return port 4. At this time, the fuel in the fuel storage tank 100 is continuously operated and then delivered to the fuel nozzle through the fuel output port 6, and directly added to the fuel vehicle. (2) The liquid level 12 of the fuel storage tank 100 is monitored by the liquid level gauge 9. When the liquid level 12 is lower than the limit, fuel is added to the fuel storage tank 100 through the fresh oil inlet 3. At the same time, according to the pressure control system, the gas on the top of the fuel tank is discharged through the gas recovery pipeline 2 through the pressure sensor 8 and the first valve 11, and a slight positive pressure is maintained in the tank to ensure the safety of the gas station system. The hourly processing flow rate of the liquid phase circulation system is 1 / 5 of the volume of the fuel storage tank 100, that is, the flow rate of the circulation system is set to 6m³ / h. 3 / h; Furthermore, in conjunction with the apparatus and preparation method of the nanobubble fuel generation unit in Example 1, it should be noted that: When using this external nanobubble fuel generation unit, the fuel first enters its dissolved gas unit 10. Under a pressure of 0.5 MPa provided by a pressurized pump, it is efficiently mixed with introduced nitrogen gas in the dissolved gas unit 10 to form a liquid with a pre-dissolved gas saturation of over 80%. Subsequently, this liquid enters the nanobubble generation reactor filled with oleophobic fiber modules 204 and flows through the fiber bed at a flow rate of 1.5 m / s, forming a large number of nanobubbles. These nanobubbles are then injected back into the fuel storage tank 100 along with the fuel through the circulating oil outlet 405 on the circulating oil return port 4, resulting in nanobubble fuel. The parameters of the oleophobic fiber module 204 are as follows: fiber thickness of 100 mm and filling density of 0.25 g / cm³. 3 The fiber surface has a micro-nano structure with micron cavities of 1μm and nano cavities of 100nm, and the contact angle with the standard test oil hexadecane is greater than 140°.

[0044] Application Example 2 This application embodiment uses the nanobubble fuel preparation device and method for gas stations from Application Embodiment 1, the difference being the integration of the external nanobubble fuel generation unit based on a Venturi tube-oleophobic fiber reactor from Embodiment 2; the hourly processing flow rate of the liquid phase circulation system is 1 / 10 of the fuel storage tank's 100 cubic meter volume, i.e., the circulation system flow rate is set to 3 m³ / h. 3 / h.

[0045] Furthermore, in conjunction with the apparatus and preparation method of the nanobubble fuel generation unit in Example 2, it should be noted that: Nitrogen gas is introduced through gas passage 1 in the gas management system to the vicinity of the gas intake port 404 of the Venturi tube 40 of the external nanobubble fuel generation unit 7 based on the Venturi tube-oleophobic fiber reactor. Then, the liquid phase circulation system is activated to extract fuel from the circulating oil extraction port 5 and transport it to the nanobubble fuel generation unit 7. The fuel flows through the Venturi tube 40 at a velocity of 25 m / s, generating a negative pressure of approximately -0.3 MPa at the throat 402. This automatically draws in nitrogen gas, which mixes violently with the fuel to form a pre-dissolved gas liquid. The resulting pre-dissolved gas liquid then... The fuel enters a nanobubble generating reactor connected to the outlet of the expansion section 403 of the Venturi tube 40. The fuel flows through the oleophobic fiber module 204 inside the reactor, generating nanobubbles. Simultaneously, the large bubble separator 30 above the reactor separates and discharges large bubbles 205 with a particle size >200nm through the exhaust port 301. The nanobubble fuel is then injected back into the fuel storage tank 100 through the circulating oil outlet 405 on the circulating oil return port 4. The Venturi tube throat 402 has a diameter of 4mm. The oleophobic fiber module 204 has the following parameters: fiber thickness of 100mm and packing density of 0.25g / cm³. 3The fiber surface has a micro-nano structure with micron cavities of 1μm and nano cavities of 100nm, and the contact angle with the standard test oil hexadecane is greater than 140°.

[0046] Application Example 3 This application embodiment uses the nanobubble fuel preparation device and method for gas stations from Application Embodiment 1. The difference lies in integrating the external nanobubble fuel generation unit based on a swirl-release-particle bed reactor from Embodiment 3. The hourly processing flow rate of the liquid phase circulation system is 1 / 15 of the 100-volume volume of the fuel storage tank, i.e., the circulation system flow rate is set to 2m³ / h. 3 / h.

[0047] Furthermore, in conjunction with the apparatus and preparation method of the nanobubble fuel generation unit in Example 3, it should be noted that: Nitrogen gas is directly introduced into the gas-liquid mixing unit of the external nanobubble fuel generation unit 7 based on the swirling gas release-particle bed reactor through gas passage 1 in the gas phase management system. The liquid phase circulation system is activated, and fuel gas is drawn from the circulating oil extraction port 5 and efficiently mixed with the introduced nitrogen gas in the gas-liquid mixing unit. Then, the mixture is injected into the swirling generator 50 at a flow rate of 20 m / s through the tangential liquid inlet 501. In the intense swirling field, the injected nitrogen gas is rapidly sheared into microbubbles and thoroughly mixed with the fuel gas. When the gas-liquid mixture flows through oleophobic particles 601 filled with particles of different sizes, the bubbles are further refined into nanoscale particles due to intense collisions and shearing between the particles, forming nanobubbles. Large bubbles that do not meet the requirements rise to the top at the center of the swirling flow and are discharged through the exhaust port 502, while the nanobubbles that meet the requirements pass through the bottom particle filter 506 along with the fuel gas and are injected back into the fuel storage tank 100 through the circulating oil outlet 405 on the circulating oil return port 4. The height-to-diameter ratio H / D of the swirling generator 50 is... The ratio is 3:1, meaning a diameter of 50mm and a height of 150mm; the ratio of the height H1 between the top and bottom particle filters to the height H of the cyclone generator is 1 / 2:1; the annular space is filled with two types of oleophobic particles of different sizes at a volume filling rate of 60%, and the oleophobic particles are preferably made of 304 stainless steel; the larger oleophobic particle has a diameter of 5mm and the smaller oleophobic particle has a diameter of 2mm, meaning the ratio of the diameter of the larger oleophobic particle to the smaller oleophobic particle is 2.5:1; the mass ratio of the larger oleophobic particle to the smaller oleophobic particle is 25:1.

[0048] Application Example 4 This application embodiment uses the preparation device and method for nanobubble fuel at gas stations from Application Embodiment 1. The difference lies in integrating the external nanobubble fuel generation unit based on a nanoporous sintered metal mesh reactor from Embodiment 4. The hourly processing flow rate of the liquid phase circulation system is 1 / 20 of the 100-liter volume of the fuel storage tank, i.e., the circulation system flow rate is set to 1.5 m³ / h. 3 / h.

[0049] Furthermore, in conjunction with the apparatus and preparation method of the nanobubble fuel generation unit in Example 4, it should be noted that: Nitrogen gas is continuously introduced into the internal cavity of the external nanobubble fuel generation unit 7, which is based on a nanoporous sintered metal mesh reactor, through gas passage 1 in the gas phase management system, maintaining its internal pressure slightly higher than that of the fuel storage tank 100; then the liquid phase circulation system is started to extract fuel from the circulating oil extraction port 5, at a pressure of 3... A tangential flow velocity of m / s enters through the circulating oil inlet 71, establishing a circulation between the fuel storage tank 100 and the external nanobubble fuel generation unit 7. During this process, nitrogen gas inside the reactor is forced to precipitate from the sides of the nanoporous sintered metal mesh 74 on its cylindrical surface under pressure. When the nitrogen gas passes through the outermost nanoscale foaming layer 743 of the nanoporous sintered metal mesh 74, it is sheared into a large number of nanobubbles by the circulating fuel that washes over the nanoporous sintered metal mesh 74. These nanobubbles flow out with the fuel gas from the nanobubble fuel outlet 73 and are injected back into the fuel storage tank 100 through the circulating oil outlet 405 on the distributed circulating oil return port 4. The nanoporous sintered metal mesh 74 is made of molybdenum-titanium alloy. The pore size of the support layer 741 of the nanoporous sintered metal mesh 74 is 35 μm, the pore size of the transition layer 742 is 12 μm, and the pore size of the foaming layer 743 is 8 nm.

[0050] Application Example 5 The apparatus and method for preparing nanobubble fuel at gas stations used in this application embodiment are the same as those in application embodiment 4, except that the hourly processing flow rate of the liquid phase circulation system is 1 / 4 of the 100 cubic meter volume of the fuel storage tank, i.e., the flow rate of the circulation system is set to 7.5 m³ / h. 3 / h.

[0051] Application Example 6 The apparatus and method for preparing nanobubble fuel at gas stations used in this application embodiment are the same as those in application embodiment 4, except that the hourly processing flow rate of the liquid phase circulation system is 1 / 25 of the fuel storage tank volume of 100, that is, the flow rate of the circulation system is set to 1.2 m³ / h. 3 / h.

[0052] Performance testing To verify the actual effect of the nanobubble fuel prepared by the device of the present invention, the following tests and analyses were conducted after the system ran continuously for 24 hours to ensure that the fuel in the storage tank was fully treated.

[0053] Test sample: Experimental group: Using the fuel nozzle connected to the fuel outlet of the device of the present invention, samples of nanobubble fuel were taken from the fuel nozzle in Examples 1-6. Control group: Samples were taken from ordinary fuel of the same source and grade (92#) that had not been treated.

[0054] Note: The gas concentration at the top of the tank has been tested and found to be below the safe range. The volatile gases or oil vapors in the diesel storage tank are mainly pentane, hexane, heptane, octane, etc. Detection is performed using a portable infrared multi-gas detector, which can simultaneously detect the concentration of combustible gas (LEL%) and oxygen concentration (O2%). When the percentage of the lower explosive limit of combustible gas is <1% LEL, the explosion risk is considered negligible.

[0055] Test method: 1) Fuel characteristic characterization: The concentration and particle size D50 distribution of nanobubbles were determined using nanoparticle tracking analysis (NTA). 2) Engine bench test: A. The experimental group (nanobubble fuel) and the control group (ordinary fuel) were compared and tested on the same calibrated engine bench. The engine was run according to the national standard test cycles (e.g., ESC, WLTC, etc.). The engine output torque and power under different operating conditions were measured and recorded. An emissions analyzer was used to measure and record the emissions of major pollutants (e.g., CO, HC, NOx) in the exhaust gas.

[0056] B. Data Processing and Effect Calculation: The data from the experimental group were compared with those from the control group, and the relative rate of change of each performance index was calculated (the data in the table were calculated with the performance of the control group as the baseline (i.e., 0%)): Dynamic change (%) = (Average power of experimental group - Average power of control group) / Average power of control group × 100% Exhaust emission reduction rate (%) is calculated separately for each pollutant. For example: HC emission reduction rate (%) = (HC emissions from control group - HC emissions from experimental group) / HC emissions from control group × 100% Table 1 The data above shows that, compared to Application Examples 1-4, while Application Example 5 resulted in a smaller D50 for the nanobubbles in the nanobubble fuel, the excessively high processing flow rate led to a lower concentration of nanobubbles. Application Example 6 produced nanobubble fuel with a larger D50 and lower concentration of nanobubbles. Furthermore, a comparison between Application Examples 5-6 and Application Examples 1-4 reveals that the hourly processing flow rate of the liquid-phase circulation system is crucial, significantly improving combustion performance and exhaust emissions. Therefore, Application Examples 1-4 can stably and efficiently produce nanobubble fuel with significantly improved combustion performance.

[0057] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A preparation device of a gas station nanobubble fuel oil, characterized in that, The preparation device is integrated in a fuel storage tank of a gas station, and comprises four systems, namely, a gas phase management system, a liquid phase circulation system, an oil inlet and outlet system, and a monitoring system; The gas phase management system comprises a gas passage and a gas recovery pipeline; The liquid phase circulation system comprises a circulating oil extraction port and a circulating oil return port integrated in the fuel storage tank, and an external nano-bubble fuel generating unit connected with the circulating oil extraction port and the circulating oil return port outside the fuel storage tank; the external nano-bubble fuel generating unit is connected with the gas passage; The oil inlet and outlet system comprises a fresh oil inlet and a fuel outlet integrated in the fuel storage tank; the fuel outlet is connected with a fuel gun; The monitoring system comprises a liquid level meter integrated in the fuel storage tank and a pressure control system outside the fuel storage tank.

2. The preparation device according to claim 1, characterized in that The circulating oil return port is of a distributed design, and a plurality of circulating oil outlets are distributed on the entire circulating oil return port.

3. The preparation device according to claim 1, characterized in that The external nano-bubble fuel generating unit is any one of nano-bubble fuel generating devices based on an oleophobic fiber reactor, a Venturi tube-oleophobic fiber reactor, a cyclone gas releasing-particle bed reactor, and a nano-pore sintered metal mesh reactor.

4. The preparation device according to claim 3, characterized in that The nano-bubble fuel generating device based on the oleophobic fiber reactor comprises a gas dissolving unit and a nano-bubble generating reactor; the gas dissolving unit comprises a pressurizing pump and a gas mixer; the nano-bubble generating reactor is filled with an oleophobic fiber module, a liquid inlet of the nano-bubble generating reactor is arranged on one side of the oleophobic fiber module and connected with an outlet of the gas dissolving unit, and a liquid outlet of the nano-bubble generating reactor is arranged on the other side of the bottom of the oleophobic fiber module and used for outputting nano-bubble fuel; the oleophobic fiber module is a fiber bed layer formed by stacking the super-oleophobic fiber in disorder.

5. The preparation device according to claim 3, characterized in that The nano-bubble fuel generating device based on the Venturi tube-oleophobic fiber reactor comprises a Venturi tube, a nano-bubble generating reactor, and a large bubble separator; the Venturi tube comprises a converging section, a throat, and a diverging section connected in sequence, a gas suction hole is arranged at the throat of the Venturi tube, the nano-bubble generating reactor is filled with an oleophobic fiber module, a liquid inlet of the nano-bubble generating reactor is arranged on one side of the oleophobic fiber module and connected with an outlet of the diverging section of the Venturi tube, and a liquid outlet of the nano-bubble generating reactor is arranged on the other side of the bottom of the oleophobic fiber module and used for outputting nano-bubble fuel; the oleophobic fiber module is a fiber bed layer formed by stacking the super-oleophobic fiber in disorder; the large bubble separator is arranged above the nano-bubble generating reactor and provided with an exhaust port at the top.

6. A preparation device according to claim 4 or 5, characterised in that The surface of the super-oleophobic fiber has a micro-nano composite structure, comprising micron-sized cavities with a diameter of 0.25-5 microns and nanometer-sized cavities with a diameter of 10-200 nanometers, and the contact angle of the super-oleophobic fiber to water is greater than 150°, and the contact angle to standard test oil hexadecane is greater than 130°; the fiber bed layer has a fiber thickness of 50-200 mm and a filling density of 0.15-0.35 g / cm 3 . 3 .

7. The preparation device according to claim 3, characterized in that The nanobubble fuel generating device based on the cyclone gas release-particle bed reactor comprises a cyclone generator and a particle bed in the cyclone generator; a tangential liquid inlet is arranged on the upper end of the shell wall of the cyclone generator, an exhaust outlet and a liquid outlet are arranged on the top and bottom of the shell respectively, a top particle filter screen and a bottom particle filter screen are arranged in the shell of the cyclone generator below the tangential liquid inlet, the particle bed is contained in the area surrounded by the side wall of the shell of the cyclone generator, the top particle filter screen and the bottom particle filter screen, the area is filled with at least two kinds of oil-repellent particles with different particle sizes at a volume filling rate of 50%-70%, and the particle bed is formed; the ratio of the height H1 between the top particle filter screen and the bottom particle filter screen to the height H of the cyclone generator is (1 / 3-2 / 3):1; and the height-diameter ratio H / D of the cyclone generator is (2-5):

1.

8. The preparation device according to claim 7, characterized in that The particle size of the large oil-repellent particles in the two kinds of oil-repellent particles with different particle sizes is 3-10 mm, and the particle size of the small oil-repellent particles is 1-4 mm; and the particle size ratio of the large oil-repellent particles to the small oil-repellent particles is (1.5-5):

1.

9. The preparation device according to claim 3, characterized in that The nanobubble fuel generating device based on the nanometer-pore metal sintering net reactor comprises a vertical tank body and a nanometer metal sintering net in the vertical tank body, the structure of the nanometer-pore metal sintering net comprises a support layer, a transition layer and a foaming layer arranged in sequence from inside to outside; the support layer comprises a functional section and a welding neck section in the axial direction, and the welding neck section is located above the functional section; a tangential circulating oil inlet is arranged on the upper side wall of one side of the vertical tank body, a nanobubble fuel outlet is arranged at the bottom, and a gas inlet pipe is connected to the top; one end of the gas inlet pipe is located outside the vertical tank body and is used for connecting an external gas passage, and the other end extends vertically downward and deeply into the inside of the vertical tank body and is connected to the welding neck section of the support layer; the welding neck section of the support layer is connected to the pipe opening of the outer end of the gas inlet pipe through a girth weld; and a circular sealing plate is welded to the bottom of the nanometer metal sintering net and is used for sealing the bottom of the gas passage.

10. The preparation device according to claim 9, characterized in that The pore diameter of the support layer of the nanometer metal sintering net is 20-50 microns, the pore diameter of the transition layer is 5-20 microns, and the pore diameter of the foaming layer is 0.5-10 nm.

11. A method for preparing gas bubble nanobubble fuel for a gas station, using the preparation device according to any one of claims 1-10, characterized in that, The method comprises the following steps: (1) nitrogen is introduced into the external nanobubble fuel generating unit through the gas passage in the gas phase management system, the liquid phase circulation system is started, fuel is extracted from the circulating oil extraction outlet, the fuel is transported to the external nanobubble fuel generating unit, and the nanobubble fuel obtained through treatment is injected back into the fuel storage tank through the circulating oil outlet on the circulating oil return port; at this time, the fuel in the fuel storage tank is transported to the fuel filling gun through the fuel output port after continuous operation, and is directly filled into the fuel vehicle; (2) the liquid level of the fuel storage tank is monitored through a liquid level meter, fuel is supplemented into the fuel storage tank through a fresh oil inlet; at the same time, the gas on the top of the fuel tank is discharged through a gas recovery pipeline according to the pressure control system, and a slight positive pressure is maintained in the tank to ensure the safety of the gas station system.

12. The method of claim 11, wherein, The flow rate of fuel oil extracted from the circulating oil extraction port per hour in the liquid phase circulating system is 1 / 20 to 1 / 5 of the volume of the fuel oil storage tank. The flow rate of fuel oil extracted from the circulating oil extraction port per hour in the liquid phase circulating system is 1 / 20 to 1 / 5 of the volume of the fuel oil storage tank.

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