Method and device for generating nano-bubble fuel on line

Abstract

The invention discloses a method for generating nano-bubble fuel on line, which comprises the following steps of: continuously injecting fuel oil into a preparation unit comprising two or more stages of serially connected jet circulation dissolvers and a rotational flow pressure relief device, and gradually accelerating the flow rate of liquid to form jet and negative pressure effects; gas is sucked into the jet circulation dissolvers and is in contact with fuel oil to be dissolved, then the gas sequentially passes through the jet circulation dissolvers which are connected in series subsequently, circulation is formed in the dissolvers, and therefore the gas and the gas injected at the first stage are mixed and dissolved for multiple times; fuel oil containing soluble gas and undissolved gas enters a rotational flow pressure relief device of the preparation unit, the undissolved gas is separated out and returns to a gas suction area of the jet circulation dissolver, and the nano-bubble fuel oil is continuously discharged out of the preparation unit. By adopting the method and the device provided by the invention, the efficiency of converting the soluble gas into the nanobubbles can be effectively improved, and the concentration of the nanobubbles in the prepared nanobubble fuel can reach 2 * 10 < 8 >-5 * 10 < 8 > / ml.

Description

Technical Field

[0001] The present invention belongs to the technical field of high-end equipment, and in particular, relates to a method and a device for online generation of nano bubble fuel. Background Art

[0002] More and more gas turbines are used in power generation, ship propulsion and other fields. Adding hydrogen to the fuel is an important way to reduce carbon and nitrogen emissions, and is also an important direction for the clean use of hydrogen energy and enhanced combustion.

[0003] The maximum laminar combustion velocity of hydrogen in air is 306 cm / s, while that of methane is 37.6 cm / s. The propagation speed of hydrogen flame is more than 8 times that of natural gas. Traditional hydrogen blending uses gas-liquid dual fuel to enter the combustion chamber, and there is a "hydrogen flame reflux" problem. Although efficient combustion can be achieved, the faster combustion speed leads to unstable combustion and even deflagration thermoacoustic oscillation, affecting safety and stability.

[0004] Nanobubbles can exist stably in liquids, and the added hydrogen nanobubbles will not cause backfire. Moreover, the fuel mixed with nanobubbles has higher thermal conductivity. The spray produced after high-pressure injection has a large specific surface area, a large spray cone angle, and a small penetration distance, thereby effectively improving the mixing uniformity of fuel and gas, improving the thermal efficiency of the engine, and reducing pollutant emissions during incomplete combustion of the fuel.

[0005] CN201480053733.X discloses a nanobubble generator for preparing a nanobubble liquid solution, which generates nanobubbles by cavitation, fluid shearing and release processes. However, this method is only for water systems. When used for the preparation of nanobubble fuel oil, cavitation and fluid shearing can easily cause safety accidents and are difficult to apply.

[0006] The concentration of nanobubbles and the concentration of dissolved gases show a certain correlation, and the use of dissolved gas pressure release method to obtain nanobubble fuel has received widespread attention. CN202010665795.3 discloses a compressed nano hydrogen bubble diesel mixed fuel preparation device, method and use, which makes hydrogen and diesel reach a predetermined pressure, and then releases the hydrogen / diesel solution in the compression cylinder to the oil-gas separator for separation, and then obtains nano hydrogen bubble / diesel mixed fuel. CN201910579114.9 discloses a hedge mixed nano hydrogen bubble diesel mixed fuel preparation device, method and use. The patent uses a corrugated pipe wall to strengthen hydrogen dissolution, uses a buffer to extend the residence time, and finally obtains nano bubble fuel through pressure release and separation equipment. CN202111366716.X discloses a supply control system and method for engine oxygen-enriched micro-nano bubble fuel, and obtains liquid fuel containing nano bubbles through an oxygen-enriched micro-nano fuel generation system, an oxygen-enriched micro-nano bubble fuel storage device, a pressure limiting valve, and an oil-gas separation device. However, the above-mentioned patents all require an overly large oil-gas separator and are unable to generate nano bubble fuel online in a compact engine space. Summary of the invention

[0007] The purpose of the present invention is to overcome the deficiencies of the above-mentioned prior art, thereby providing a method and device for online generation of nano bubble fuel, so as to improve the efficiency of converting dissolved gas into nano bubbles when preparing nano bubble fuel.

[0008] To achieve the above object, the first aspect of the present invention provides a method for online generation of nano bubble fuel, comprising the following steps:

[0009] S1: Fuel oil is continuously injected into a preparation unit including two or more stages of jet circulation dissolvers connected in series and a cyclone pressure releaser. In the first stage of the jet circulation dissolver of the preparation unit, the liquid flow rate gradually increases after entering the gradually contracting inlet of the jet circulation dissolver to form a jet and negative pressure effect, so that the gas is sucked into the jet circulation dissolver and contacts with the fuel oil to dissolve, and then passes through the subsequent one or more stages of jet circulation dissolvers connected in series in sequence, and in each stage of the jet circulation dissolver, a circulation is formed by means of an inner cylinder provided inside the jet circulation dissolver, so as to be mixed and dissolved with the gas injected in the first stage for multiple times;

[0010] S2: The fuel oil containing dissolved gas and undissolved gas enters the cyclone pressure releaser of the preparation unit, the undissolved gas is separated from the cyclone pressure releaser and returned to the suction area of ​​the jet circulation dissolver, and the nano bubble fuel oil is continuously discharged from the preparation unit.

[0011] According to the present invention, the gas is hydrogen or methane, which is dehydrated before being injected into the preparation unit and has a pressure of 3.1 to 3.9 MPa; the fuel oil is selected from diesel, kerosene and ethanol, and the pressure of the fuel oil liquid feed is set to 3 to 5 MPa.

[0012] According to the present invention, the residence time of the fuel oil in the jet circulation dissolver is 2 to 10 seconds, and the number of jet circulation dissolvers connected in series meets the liquid residence time.

[0013] According to a preferred embodiment of the present invention, the residence time of the fuel oil in the jet circulation dissolver is set as follows:

[0014] When the fuel oil temperature is -10 to 10°C, the residence time is 8 to 10 seconds; when the fuel oil temperature is 10 to 30°C, the residence time is 5 to 8 seconds; when the fuel oil temperature is 30 to 90°C, the residence time is 2 to 5 seconds.

[0015] Furthermore, during the dissolution process of the liquid fuel oil in contact with the gas in the jet circulation dissolver, the liquid Reynolds number of the jet circulation is 3400-34000, and the liquid velocity at the tapered inlet end of the jet circulation dissolver is 4-40 m / s.

[0016] Furthermore, inside the cyclone pressure relief device, the tangential velocity of the cyclone of the liquid fuel oil containing dissolved gas is 5 to 20 m / s, and the centrifugal acceleration of the cyclone is 2500 to 40000 m / s. 2 The residence time of the liquid in the cyclone pressure relief device is 0.08 to 1 s.

[0017] In a second aspect of the present invention, there is provided an apparatus for producing nano bubble fuel online, comprising a preparation unit, a continuous fuel oil inlet disposed at the front end of the preparation unit, and a continuous nano bubble fuel oil outlet disposed at the rear end of the preparation unit, wherein the preparation unit comprises two or more stages of jet circulation dissolvers connected in series, and a swirl pressure releaser connected to the rear end of the last stage of the jet circulation dissolver, wherein:

[0018] The front end of the jet circulation dissolver is a tapered inlet, and the rear end is a circulation outlet. The fuel oil continuous inlet is connected to the tapered inlet of the first-stage jet circulation dissolver, and the circulation outlet of the previous-stage jet circulation dissolver is connected to the tapered inlet of the next-stage jet circulation dissolver. Each stage of the jet circulation dissolver is provided with an inner cylinder, and the front end and the rear end of the inner cylinder correspond to the tapered inlet and the circulation outlet, respectively, and the interior of the jet circulation dissolver is divided into a forward flow area inside the inner cylinder and a return flow area outside the inner cylinder. In addition, the first-stage jet circulation dissolver is also provided with a dissolver gas inlet at a position close to the tapered inlet.

[0019] The main body of the cyclone pressure releaser is a cyclone body cavity, a tangential inlet is provided on the upper side wall of the cyclone body cavity, and a gas outlet and a nano bubble fuel oil outlet are provided at the top and bottom respectively; wherein the tangential inlet is connected to the circulation outlet of the last jet circulation dissolver, and the nano bubble fuel oil continuous outlet is connected to the nano bubble fuel oil outlet of the cyclone pressure releaser.

[0020] According to the present invention, the diameter of the terminal channel of the tapered inlet of the jet circulation dissolver is 1 to 5 mm, the diameter of the forward flow area inside the inner tube is 1.5 to 3 times the diameter of the terminal channel of the tapered inlet, and the cross-sectional area of ​​the return flow area is 0.8 to 9 times the cross-sectional area of ​​the forward flow area.

[0021] Furthermore, the length of the inner cylinder of the jet circulation dissolver is 10 to 200 times the diameter of the terminal channel of the tapered inlet, and the distance between the right end surface of the inner cylinder and the terminal cross section of the tapered inlet is 2 to 20 times the diameter of the terminal channel of the tapered inlet.

[0022] Furthermore, the diameter of the tangential inlet of the swirl pressure relief device is 2 to 8 mm, and the diameter of the swirl cavity is equal to 3 to 9 times the diameter of the tangential inlet.

[0023] Furthermore, the distance between the axis of the tangential inlet and the top end surface of the cyclone pressure relief device is 2 to 5 times the diameter of the tangential inlet, and the distance between the axis of the tangential inlet and the axis of the liquid outlet of the cyclone pressure relief device is 10 to 50 times the diameter of the tangential inlet.

[0024] The method and device for online generation of nanobubble fuel of the present invention can effectively improve the efficiency of converting dissolved gas into nanobubbles when preparing nanobubble fuel. The concentration of nanobubbles in the prepared nanobubble fuel can reach 2×10 8 ~5×10 8 Pieces / mL. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the device and process for online generation of nano bubble fuel of the present invention, wherein the multi-stage jet circulation dissolver is in the form of front-to-back series connection.

[0026] Figure 2 for Figure 1 Schematic diagram of a multi-stage jet circulation dissolver in a device for online production of nano bubble fuel in the form of upper and lower series connection. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present invention are described clearly and completely below in conjunction with the accompanying drawings. It should be understood that the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of the present invention.

[0028] Example 1: Device and process for online generation of nano bubble fuel

[0029] like Figure 1 As shown, the device for producing nano bubble fuel online of the present invention comprises a preparation unit, a fuel oil continuous inlet 3 arranged at the front end of the preparation unit, and a nano bubble fuel oil continuous outlet 4 arranged at the rear end of the preparation unit, wherein the preparation unit comprises two or more stages of jet circulation dissolvers 1 connected in series, and a cyclone pressure releaser 2 connected to the rear end of the last stage of the jet circulation dissolver 1.

[0030] Furthermore, the front end of the jet circulating dissolver 1 is a tapered inlet 11, and the rear end is a circulation outlet 12, the fuel oil continuous inlet 3 is connected to the tapered inlet 11 of the first-stage jet circulating dissolver 1, and the circulation outlet 12 of the previous-stage jet circulating dissolver 1 is connected to the tapered inlet 11 of the next-stage jet circulating dissolver 1; each jet circulating dissolver 1 is provided with an inner cylinder 13 inside, and the front end and rear end of the inner cylinder 13 correspond to the tapered inlet 11 and the circulation outlet 12 respectively, and the interior of the jet circulating dissolver 1 is divided into a forward flow area 14 inside the inner cylinder 13 and a return flow area 15 outside the inner cylinder 13; and the first-stage jet circulating dissolver 1 is also provided with a dissolver gas inlet 16 at a position close to the tapered inlet 11.

[0031] The main body of the cyclone pressure releaser 2 is a cyclone body chamber 21, a tangential inlet 22 is provided on the upper side wall of the cyclone body chamber 21, and a gas outlet 24 and a nano bubble fuel oil outlet 23 are provided at the top and bottom respectively; wherein the tangential inlet 22 is connected to the annular flow outlet 12 of the last stage jet annular flow dissolver 1, and the nano bubble fuel oil continuous outlet 4 is connected to the nano bubble fuel oil outlet 23 of the cyclone pressure releaser 2.

[0032] In addition, the dissolver gas inlet 16 of the first-stage jet circulation dissolver 1 is connected to the gas material through the gas material pipeline 5, and the gas outlet 24 of the cyclone pressure release device 2 is also connected to the dissolver lifting inlet 16 through the reflux pipeline 6, which is used to return the gas separated by the cyclone pressure release device 2 to the suction area of ​​the jet circulation dissolver 1.

[0033] The jet circulation dissolver 1 can enhance the dissolution of gas, and its principle is as follows:

[0034] The fuel oil liquid is injected from the tapered inlet 11 of the jet circulation dissolver 1 through the fuel oil continuous inlet 3, and the liquid speed gradually increases, forming a jet and negative pressure effect. The negative pressure effect sucks the gas from the gas inlet 16 of the jet circulation dissolver 1, and the gas-liquid mixture enters the forward flow area 14 inside the inner tube 13 under the action of the jet. Since the inner tube 13 divides the jet circulation dissolver 1 into the forward flow area 14 and the return flow area 15, a part of the gas-liquid mixture is discharged from the circulation outlet 12, and a part enters the return flow area 15, forming a circulation flow. In the process of jet circulation, the gas-liquid mass transfer area and the liquid phase turbulence are enhanced, and the dissolution rate is greatly improved. At the same time, the return flow area 15 prolongs the liquid residence time, and the liquid at the circulation outlet 12 is more likely to reach a saturated state.

[0035] Preferably, the diameter of the end channel of the tapered inlet 11 of the jet circulation dissolver 1 is 1 to 5 mm, the diameter of the forward flow area 14 inside the inner tube 13 is 1.5 to 3 times the diameter of the end channel of the tapered inlet 11, and the cross-sectional area of ​​the return flow area 15 is 0.8 to 9 times the cross-sectional area of ​​the forward flow area 14.

[0036] The length of the inner cylinder 13 of the jet circulation dissolver 1 is 10 to 200 times the diameter of the end channel of the tapered inlet 11, and the distance between the left end face of the inner cylinder 13 (corresponding to the end face of the tapered inlet 11) and the end cross section of the tapered inlet 11 is 2 to 20 times the diameter of the end channel of the tapered inlet 11.

[0037] The cyclone pressure release device 2 can enhance the generation of nanobubbles, and its principle is as follows:

[0038] The cyclone field has special velocity distribution characteristics and pressure gradient distribution characteristics; the tangential velocity of the cyclone field can form a large centrifugal acceleration, which can be used to efficiently separate micro bubbles from the liquid. The cyclone field presents a pressure gradient characteristic of high wall pressure and low center pressure; the cyclone pressure gradient is usually caused by the tangential velocity, and the pressure gradient is relatively uniform. The decompression rate of the cyclone field does not change with the position, showing a stable decompression effect.

[0039] The cyclone pressure release device 2 can produce a stable pressure release effect, converting dissolved gas into bubble-state gas, and at the same time, under the action of centrifugal acceleration, concentrate the micron and millimeter bubbles into the cyclone negative pressure area and quickly separate them from the gas outlet 24 at the top, thereby avoiding the Ostwald ripening effect of large bubbles on nanobubbles (the process of large bubbles absorbing small bubbles) and increasing the concentration of nanobubbles remaining in the liquid.

[0040] Preferably, the diameter of the tangential inlet 22 of the cyclone pressure relief device 2 is 2 to 8 mm, and the diameter of the cyclone cavity 21 is 3 to 9 times the diameter of the tangential inlet 22 .

[0041] The distance between the axis of the tangential inlet 22 and the top end surface of the cyclone pressure relief device 2 is 2 to 5 times the diameter of the tangential inlet 22 , and the distance between the axis of the tangential inlet 22 and the axis of the liquid outlet 23 of the cyclone pressure relief device 2 is 10 to 50 times the diameter of the tangential inlet 22 .

[0042] like Figure 2 As shown, in the device for online generation of nano bubble fuel of the present invention, two or more stages of jet circulation dissolvers 1 are connected in series, which is different from Figure 1 The form shown is that two or more stages of jet circulation dissolvers 1 are connected in series. Figure 2 The form shown is that two or more stages of jet circulation dissolvers 1 are connected in series in an upper and lower position. It is easy to understand that the rear end of the bottom-level jet circulation dissolver 1 is connected to a swirl pressure releaser 2, and the fuel oil continuous inlet 3 is connected to the tapered inlet 11 of the first-level jet circulation dissolver 1 arranged at the top layer, and the nano bubble fuel oil continuous outlet 4 is connected to the nano bubble fuel oil outlet 23 of the swirl pressure releaser 2.

[0043] It is easy for those skilled in the art to understand that although the above examples illustrate the front-to-back series connection and the top-to-bottom series connection of the multi-stage jet circulation dissolvers, based on the actual site conditions, the front-to-back series connection combined with the top-to-bottom series connection, or other possible series connection forms can be adopted as needed. This is obvious and all belong to the scope of the present invention.

[0044] The method for online generation of nano bubble fuel of the present invention comprises the following steps:

[0045] S1: Fuel oil is continuously injected into a preparation unit including two or more stages of jet circulation dissolvers 1 connected in series and a cyclone pressure releaser 2. In the first stage of the jet circulation dissolver 1 of the preparation unit, the liquid flow rate is gradually accelerated after entering the gradually contracting inlet 11 of the jet circulation dissolver 1 to form a jet and negative pressure effect, so that the gas is sucked into the jet circulation dissolver 1 and dissolved in contact with the fuel oil, and then passes through the subsequent one or more stages of the jet circulation dissolvers 1 connected in series in sequence, and in each stage of the jet circulation dissolver 1, a circulation is formed by means of the inner cylinder 13 provided inside the jet circulation dissolver, so as to be mixed and dissolved with the gas injected in the first stage for multiple times;

[0046] S2: The fuel oil containing dissolved gas and undissolved gas enters the cyclone pressure releaser 2 of the preparation unit, the undissolved gas is separated from the cyclone pressure releaser 2 and returned to the air intake area of ​​the jet circulation dissolver 1, and the nano bubble fuel oil is continuously discharged from the preparation unit.

[0047] By adopting the above process of the present invention, the liquid fuel oil after cyclone pressure release contains a certain concentration of nano bubbles, and the concentration of nano bubbles reaches 2×10 8~5×10 8 Pieces / mL.

[0048] According to the present invention, the gas may be hydrogen or methane. The gas should be dehydrated before being injected into the preparation unit and have a pressure of 3.1 to 3.9 MPa.

[0049] Furthermore, the fuel oil can be diesel, kerosene, ethanol or other fuel oils, and the residence time of the fuel oil in the jet circulation dissolver 1 is 2 to 10 seconds; specifically, when the fuel oil temperature is -10 to 10°C, the residence time is 8 to 10 seconds; when the fuel oil temperature is 10 to 30°C, the residence time is 5 to 8 seconds; when the fuel oil temperature is 30 to 90°C, the residence time is 2 to 5 seconds. The lower the temperature, the slower the molecular diffusion rate of the gas in the fuel oil, and the longer the required circulation time. The number of jet circulation dissolvers 1 in series should meet the liquid residence time.

[0050] Furthermore, the concentration of nanobubbles in the fuel oil increases with the pressure of the liquid feed. Preferably, the pressure of the liquid feed is set to 3-5 MPa.

[0051] The parameter that can reflect the turbulence degree of the jet circulation is the liquid Reynolds number. The liquid Reynolds number expression of the jet circulation is: Where D is the cross-sectional diameter of the tapered inlet channel, u is the liquid velocity at the end of the tapered inlet, and ρ L is the liquid density, μ L is the viscosity of the liquid.

[0052] In the present invention, during the dissolution of liquid fuel oil in contact with gas in the jet circulation dissolver 1, the liquid Reynolds number of the jet circulation is preferably 3400-34000, and the liquid velocity at the end of the tapered inlet 11 of the jet circulation dissolver 1 is preferably 4-40 m / s.

[0053] In the present invention, the tangential velocity of the swirl of the liquid fuel oil containing dissolved gas inside the swirl pressure release device 2 is preferably 5 to 20 m / s, and the centrifugal acceleration of the swirl is preferably 2500 to 40000 m / s. 2 The residence time of the liquid in the cyclone pressure release device is preferably 0.08 to 1 second.

[0054] Example 2

[0055] This embodiment provides an apparatus and method for producing nano bubble fuel online, wherein the apparatus comprises a preparation unit, a continuous fuel oil inlet 3 arranged at the front end of the preparation unit, and a continuous nano bubble fuel oil outlet 4 arranged at the rear end of the preparation unit, wherein the preparation unit comprises two or more stages of jet circulation dissolvers 1 connected in series, and a cyclone pressure releaser 2 connected to the rear end of the last stage of the jet circulation dissolver 1. See Example 1 for details, wherein:

[0056] The diameter of the end channel of the tapered inlet 11 of the jet circulation dissolver 1 is 4 mm, the diameter of the forward flow area 14 is 2.5 times the diameter of the end channel of the tapered inlet 11 , and the cross-sectional area of ​​the return flow area 15 is equal to 3 times the cross-sectional area of ​​the forward flow area 14 .

[0057] The length of the inner cylinder 13 of the jet circulation dissolver 1 is 100 times the diameter of the terminal channel of the tapered inlet 11, and the distance between the left end surface of the inner cylinder 13 and the terminal cross section of the tapered inlet 11 is 10 times the diameter of the terminal channel of the tapered inlet.

[0058] The diameter of the tangential inlet 22 of the swirl pressure release device 2 is 2.5 mm, and the diameter of the swirl cavity 21 is equal to 8 times the diameter of the tangential inlet 22 .

[0059] The distance between the axis of the tangential inlet 22 of the cyclone pressure relief device 2 and the top end surface of the cyclone pressure relief device 2 is 4 times the diameter of the tangential inlet 22 , and the distance between the axis of the tangential inlet 22 and the axis of the liquid outlet 23 of the cyclone pressure relief device 2 is 30 times the diameter of the tangential inlet 22 .

[0060] The process of the online method for generating nano bubble fuel of this embodiment includes the following steps:

[0061] S1: Fuel oil is continuously injected into a preparation unit including three stages of jet circulation dissolvers 1 connected in series and a cyclone pressure releaser 2. In the first stage of the jet circulation dissolver 1 of the preparation unit, the liquid flow rate gradually increases after entering the gradually contracting inlet 11 of the jet circulation dissolver 1 to form a jet and negative pressure effect, so that the gas is sucked into the jet circulation dissolver 1 and contacts with the fuel oil to dissolve, and then passes through the subsequent two stages of the jet circulation dissolvers 1 connected in series in sequence, and is mixed and dissolved with the gas injected in the first stage for multiple times;

[0062] S2: The fuel oil containing dissolved gas and undissolved gas enters the cyclone pressure releaser 2 of the preparation unit, the undissolved gas is separated from the cyclone pressure releaser 2 and returned to the air intake area of ​​the jet circulation dissolver 1, and the nano bubble fuel oil is continuously discharged from the preparation unit.

[0063] In this embodiment, methane is selected as the gas, and the gas is dehydrated before being injected into the preparation unit and has a pressure of 6 MPa.

[0064] The liquid is diesel, the residence time of the fuel oil in the jet circulation dissolver 1 is 3 seconds, and the temperature of the fuel oil is 33 degrees Celsius.

[0065] The concentration of nanobubbles in the nanobubble fuel oil increases with the pressure of the liquid feed, and the pressure of the liquid feed is set to 4.5 MPa.

[0066] During the dissolution process of the liquid fuel oil in contact with the gas in the jet circulation dissolver 1, the liquid Reynolds number of the jet circulation is 23000, and the liquid velocity at the end of the tapered inlet 11 is 20 m / s.

[0067] The liquid fuel oil containing dissolved gas is inside the swirl pressure releaser 2, the swirl tangential velocity is 6.8m / s, and the swirl centrifugal acceleration is 4600m / s 2 , the residence time of the liquid in the cyclone pressure relief device 2 is 0.8s.

[0068] The length of a single jet circulation dissolver 1 is 0.8m. Combined with the known conditions: the liquid velocity at the end of the tapered inlet 11 is 20m / s, the diameter of the forward flow area 14 is 2.5 times the diameter of the end channel of the tapered inlet 11, and the cross-sectional area of ​​the return flow area 15 is equal to 3 times the cross-sectional area of ​​the forward flow area. It can be calculated that the residence time of the liquid fuel in a single jet circulation dissolver 1 is 1 second. In order to achieve the requirement of 3s for the residence time of the fuel oil in the jet circulation dissolver, three jet circulation dissolvers 1 connected in series are arranged in this embodiment.

[0069] The three series-connected jet circulation dissolvers can be arranged in a straight line (front and back), or they can be folded and arranged (up and down) according to the actual space conditions, such as Figure 2 shown.

[0070] The high-concentration nanobubble fuel oil was sampled and analyzed. Within one hour of sampling, the nanoparticle tracking analysis (NTA) method was used for measurement. The instrument model was Malvern NS300.

[0071] Nanobubble diesel fuel can be prepared by the method and device of this embodiment. The concentration of nanobubbles is 3.6×10 8 pcs / ml, as shown in Table 1.

[0072] Example 3

[0073] This embodiment is basically the same as the embodiment 2, except that, based on the embodiment 2, the number of the jet circulation dissolvers is reduced to 2, and then the experiment with the same gas-liquid flow rate is carried out.

[0074] This implementation condition means that the residence time of fuel oil in the jet circulation dissolver is reduced from 3s to 2s. The test results (Table 1) show that the nanobubble concentration is reduced to 2.1×10 8 / ml, which is lower than the nanobubble concentration in Example 2. However, it is still around 2×10 8 ~5×10 8 in the range of pcs / ml.

[0075] Example 4

[0076] This embodiment is basically the same as Embodiment 2, except that, based on Embodiment 2, the number of jet circulation dissolvers is reduced to one, and then experiments with the same gas-liquid flow rate are carried out.

[0077] This implementation condition means that the residence time of fuel oil in the jet circulation dissolver is reduced from 3s to 1s. The test results (Table 1) show that the nanobubble concentration is reduced to 0.9×10 8 / ml, which is lower than the nanobubble concentration in Example 2, less than 2×10 8 Pieces / mL.

[0078] Example 5

[0079] This embodiment is basically the same as embodiment 2, except that, on the basis of embodiment 2, the cyclone pressure release device is changed to a gas-liquid separation tank with a liquid phase residence time of 4 minutes, and the gas and liquid from the gas-liquid separation tank are mixed together to form a gas-liquid two-phase fuel. Then, the same nanobubble concentration test experiment is carried out.

[0080] The test results (Table 1) show that the nanobubble concentration is reduced to 0.5×10 8 Pieces / mL.

[0081] Cause analysis: Since large bubbles cannot separate quickly and the pressure reduction rate decreases suddenly, there is an Ostwald ripening effect, a process in which large bubbles absorb small bubbles, which reduces the concentration of nanobubbles in the liquid.

[0082] Example 6

[0083] This embodiment is basically the same as embodiment 2, except that, on the basis of embodiment 2, the liquid pressure is reduced to 1 MPa. The test results (Table 1) show that the nanobubble concentration is reduced to 0.2×10 8 Pieces / mL.

[0084] Cause analysis: The solubility of saturated gas decreases, resulting in a decrease in the total number of molecules converted into nanobubbles.

[0085] Example 7

[0086] This embodiment is basically the same as embodiment 2, except that, on the basis of embodiment 2, the pressure of the high-pressure tank is increased to 6 MPa. The test results (Table 1) show that the nanobubble concentration is increased to 4×10 8 Pieces / mL.

[0087] Cause analysis: Increasing the solubility of saturated gas increases the total number of molecules converted into nanobubbles.

[0088] Example 8

[0089] This embodiment is basically the same as Embodiment 2, except that, based on Embodiment 2, gas injection is eliminated.

[0090] This example is used as a blank sample for NTA testing of nanobubbles, confirming that the nanoparticles tested in Examples 2-7 and Examples 9-10 are nanobubbles, not nano solid particles.

[0091] Example 9

[0092] This embodiment is basically the same as embodiment 2, except that, based on embodiment 2, the nanobubble concentration is measured 2 days after sampling. The test results are shown in Table 1. It can be seen that after 2 days of placement, the nanobubble concentration decreases very little, and has good stability.

[0093] Example 10

[0094] This embodiment is basically the same as embodiment 2, except that, based on embodiment 2, the nanobubble concentration is measured 10 days after sampling. The test results are shown in Table 1. It can be seen that after 10 days of placement, the nanobubble concentration still decreases slightly, and has good stability.

[0095] Embodiment 11

[0096] This embodiment is basically the same as Embodiment 2, except that, based on Embodiment 2, the fuel oil temperature is changed from 33° C. to 2° C. The test results are shown in Table 1.

[0097] The test results showed that the concentration of nanobubbles was reduced to 0.65×10 8 It can be seen that the lower the temperature, the slower the molecular diffusion, the slower the dissolution in the jet circulation dissolver, and the slower the desorption in the cyclone pressure releaser, which ultimately leads to too low a concentration of nanobubbles.

[0098] Example 12

[0099] This embodiment is basically the same as Embodiment 2, except that, based on Embodiment 2, the fuel oil temperature is changed from 33°C to 2°C, and the number of jet circulation dissolvers is increased from 3 to 9. The test results are shown in Table 1.

[0100] The test results showed that the concentration of nanobubbles was 3.5×10 8 / ml. It can be seen that the lower the temperature, the slower the molecular diffusion, the slower the dissolution in the jet circulation dissolver, and the slower the desorption in the cyclone pressure releaser, which ultimately leads to too low a concentration of nanobubbles. The residence time increases from 3s to 9s, making up for the lack of slow diffusion at low temperatures.

[0101] Table 1

[0102] Example No. <![CDATA[Nano - bubble concentration (×10 8 / ml)]]> 2 3.6 3 2.1 4 0.9 5 0.5 6 0.2 7 4 8 0.04 9 3.2 10 3 11 0.65 12 3.5

[0103] Example 13

[0104] A combustion experiment was conducted on a gas turbine, and the flow rate of liquid fuel was 2 L / min, which is the same as the fuel flow rate entering the swirl pressure relief device in Example 2-12.

[0105] Combustion experiments were conducted using the nanobubble fuel prepared in Example 2 and the fuel prepared in Example 8. The results are shown in Table 2.

[0106] Table 2: Combustion test data

[0107]

[0108] The results in Table 2 show that the fuel tail gas with hydrogen nanobubbles has lower NOx emission concentration and is more environmentally friendly.

[0109] Embodiment 14

[0110] A combustion experiment was conducted on a gas turbine, and the flow rate of liquid fuel was 2 L / min, which is the same as the fuel flow rate entering the swirl pressure relief device in Example 2-12.

[0111] 0.1 L / min of hydrogen was injected into the liquid fuel, and a combustion experiment was carried out using the nanobubble fuel prepared in Example 2 and the gas-liquid two-phase mixed fuel prepared in Example 5. The results are shown in Table 3.

[0112] Table 3: Combustion test data

[0113]

[0114] The results in Table 3 show that the fuel tail gas with hydrogen nanobubbles has a lower NOx emission concentration and is more environmentally friendly.

[0115] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for producing nanobubble fuel online, characterized in that: The following steps are involved: S1: Fuel oil is continuously injected into a preparation unit including two or more stages of jet circulation dissolvers connected in series and a cyclone pressure releaser. In the first stage of the jet circulation dissolver of the preparation unit, the liquid flow rate gradually increases after entering the gradually contracting inlet of the jet circulation dissolver to form a jet and negative pressure effect, so that the gas is sucked into the jet circulation dissolver and contacts with the fuel oil to dissolve, and then passes through the subsequent one or more stages of jet circulation dissolvers connected in series in sequence, and in each stage of the jet circulation dissolver, a circulation is formed by means of an inner cylinder provided inside the jet circulation dissolver, so as to be mixed and dissolved with the gas injected in the first stage for multiple times; S2: The fuel oil containing dissolved gas and undissolved gas enters the cyclone pressure releaser of the preparation unit, the undissolved gas is separated from the cyclone pressure releaser and returned to the suction area of ​​the jet circulation dissolver, and the nano bubble fuel oil is continuously discharged from the preparation unit.

2. The method according to claim 1, characterized in that: The gas is hydrogen or methane, which is dehydrated before being injected into the preparation unit and has a pressure of 3.1-3.9 MPa or more; the fuel oil is selected from diesel, kerosene and ethanol, and the pressure of the fuel oil liquid feed is set to 3-5 MPa.

3. The method according to claim 1, characterized in that The residence time of the fuel oil in the jet circulation dissolver is 2 to 10 seconds, and the number of jet circulation dissolvers connected in series meets the liquid residence time.

4. The method according to claim 3, characterized in that: The residence time of fuel oil in the jet circulation dissolver is set as follows: When the fuel oil temperature is -10 to 10°C, the residence time is 8 to 10 seconds; When the fuel oil temperature is 10-30°C, the residence time is 5-8s; When the fuel oil temperature is 30-90°C, the residence time is 2-5s.

5. The method according to claim 1, characterized in that During the dissolution process of liquid fuel oil in contact with gas in the jet circulation dissolver, the liquid Reynolds number of the jet circulation is 3400-34000, and the liquid velocity at the tapered inlet end of the jet circulation dissolver is 4-40 m / s.

6. The method according to claim 1, characterized in that Inside the cyclone pressure relief device, the tangential velocity of the cyclone of liquid fuel oil containing dissolved gas is 5 to 20 m / s, and the centrifugal acceleration of the cyclone is 2500 to 40000 m / s. 2 The residence time of the liquid in the cyclone pressure relief device is 0.08 to 1 s.

7. A device for producing nano bubble fuel online, characterized in that: The device comprises a preparation unit, a continuous fuel oil inlet (3) arranged at the front end of the preparation unit, and a continuous nano bubble fuel oil outlet (4) arranged at the rear end of the preparation unit, wherein the preparation unit comprises two or more stages of jet circulation dissolvers (1) connected in series, and a cyclone pressure release device (2) connected to the rear end of the last stage of the jet circulation dissolver (1), wherein: The front end of the jet circulation dissolver (1) is a gradually contracting inlet (11), and the rear end is a circulation outlet (12); the fuel oil continuous inlet (3) is connected to the gradually contracting inlet (11) of the first-stage jet circulation dissolver (1), and the circulation outlet (12) of the previous-stage jet circulation dissolver (1) is connected to the gradually contracting inlet (11) of the next-stage jet circulation dissolver (1); each stage of the jet circulation dissolver (1) is provided with an inner cylinder (13) inside, the front end and the rear end of the inner cylinder (13) respectively correspond to the gradually contracting inlet (11) and the circulation outlet (12), and the interior of the jet circulation dissolver (1) is divided into a forward flow area (14) inside the inner cylinder (13) and a return flow area (15) outside the inner cylinder (13); and the first-stage jet circulation dissolver (1) is also provided with a dissolver gas inlet (16) at a position close to the gradually contracting inlet (11); The main body of the cyclone pressure release device (2) is a cyclone body chamber (21), the upper side wall of the cyclone body chamber (21) is provided with a tangential inlet (22), and the top and bottom are respectively provided with a gas outlet (24) and a nano bubble fuel oil outlet (23); wherein the tangential inlet (22) is connected to the annular flow outlet (12) of the last jet annular flow dissolver (1), and the nano bubble fuel oil continuous outlet (4) is connected to the nano bubble fuel oil outlet (23) of the cyclone pressure release device (2).

8. The device according to claim 7, characterized in that The diameter of the terminal channel of the tapered inlet (11) of the jet circulation dissolver (1) is 1 to 5 mm, the diameter of the forward flow area (14) inside the inner tube (13) is 1.5 to 3 times the diameter of the terminal channel of the tapered inlet (11), and the cross-sectional area of ​​the return flow area (15) is 0.8 to 9 times the cross-sectional area of ​​the forward flow area (14).

9. The device according to claim 7, characterized in that The length of the inner cylinder (13) of the jet circulation dissolver (1) is 10 to 200 times the diameter of the terminal channel of the tapered inlet (11), and the distance between the right end surface of the inner cylinder (13) and the terminal cross section of the tapered inlet (11) is 2 to 20 times the diameter of the terminal channel of the tapered inlet (11).

10. The device according to claim 7, characterized in that The diameter of the tangential inlet (22) of the cyclone pressure release device (2) is 2 to 8 mm, and the diameter of the cyclone cavity (21) is 3 to 9 times the diameter of the tangential inlet (22).

11. The device according to claim 7, characterized in that The distance between the axis of the tangential inlet (22) and the top end surface of the cyclone pressure relief device (2) is 2 to 5 times the diameter of the tangential inlet (22), and the distance between the axis of the tangential inlet (22) and the axis of the liquid outlet (23) of the cyclone pressure relief device (2) is 10 to 50 times the diameter of the tangential inlet (22).

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