Microbubble enhanced heavy oil atomization system and atomization method

Abstract

The invention discloses a microbubble enhanced heavy oil atomization system and atomization method, and belongs to the field of heavy oil reutilization, heavy oil and a gas phase form gas-liquid emulsified phase oil in a microbubble generator, then the gas-liquid emulsified phase oil is sprayed out through an atomizing nozzle, and the microbubble generator is communicated with an inlet of a buffer through a first pipeline; an outlet of the buffer is communicated with the atomizing nozzle through a second pipeline perpendicular to the first pipeline, and the atomizing nozzle is provided with a secondary air supplementing pipe. According to the invention, secondary continuous-phase gas is introduced on the basis of conventional'formation of gas-liquid emulsified phase oil and atomization through heavy oil microbubbling ', and the secondary continuous-phase gas and the gas-liquid emulsified phase oil are subjected to opposite flow mixing, so that the gas-liquid emulsified phase oil is atomized and sprayed out, and the gas-liquid emulsified phase oil is atomized and sprayed out. Micro-bubbles contained in the ejected micro-droplets can be quickly exploded for the second time, and the sizes of the micro-droplets are further dispersed, so that the droplets which are dispersed for the first time through the nozzle are crushed, refined and dispersed again.

Description

Technical Field

[0001] The present invention relates to the field of heavy oil reuse, and particularly to a microbubble-enhanced heavy oil atomization system and an atomization method. Background Art

[0002] In a refinery device, the feed nozzle of a reactor generally atomizes the feedstock oil into fine droplets and then sends them into the reactor for reaction, so that the feedstock oil can participate in the reaction faster. The degree of atomization and dispersion of the feedstock oil entering the reactor, especially during the cracking reaction, to a certain extent directly determines the effect of the reaction.

[0003] When heavy oil is used as the feedstock oil for reaction, due to the very high viscosity of heavy oil, it is difficult to directly atomize. In the prior art, heavy oil and gas are generally introduced into a microbubble generator respectively, and microbubbles are injected into the heavy oil through the microbubble generator to form a gas-liquid emulsified phase oil, and then it is ejected through an atomizing nozzle, which not only effectively improves the efficiency of the nozzle, but also can improve the atomization effect of heavy oil.

[0004] However, with the increase in the size of the reactor and the control of reaction fineness, only using the combination of microbubbles and an atomizing nozzle to atomize heavy oil, the size of the atomized droplets still cannot well meet the requirements of a large-size reactor. Summary of the Invention

[0005] The purpose of the present invention is to provide a microbubble-enhanced heavy oil atomization system and an atomization method. Based on the conventional "microbubbling of heavy oil to form a gas-liquid emulsified phase oil + atomization", a secondary continuous-phase gas is introduced, and the secondary continuous-phase gas is made to counterflow and mix with the gas-liquid emulsified phase oil, so that during the process of atomizing and ejecting the gas-liquid emulsified phase oil, the microbubbles contained in the ejected microdroplets can quickly burst for the second time, further dispersing the size of the microdroplets, and enabling the droplets once dispersed by the nozzle to be broken, refined, and dispersed again.

[0006] The technical solution adopted by the present invention to achieve the above technical purpose is: a microbubble-enhanced heavy oil atomization system, including a microbubble generator and an atomizing nozzle. Among them, heavy oil and gas form a gas-liquid emulsified phase oil in the microbubble generator and then are ejected through the atomizing nozzle. The microbubble generator is connected to the inlet of a buffer through a first pipeline, the outlet of the buffer is connected to the atomizing nozzle through a second pipeline perpendicular to the first pipeline, and the atomizing nozzle is provided with a secondary air supply pipe;

[0007] The buffer is in an L shape and consists of a horizontal pipe section and a vertical pipe section. The horizontal pipe section has equal-diameter holes, one end of the equal-diameter holes has an inner diameter gradually increasing to form a gradually expanding part, and a flow-through area is formed at the connection of the gradually expanding part and the inner cavity of the vertical pipe section. An elastic fragmentation plate is arranged in the inner cavity of the vertical pipe section.

[0008] As an optimized scheme of the above microbubble-enhanced heavy oil atomization system, the elastic broken flow plate is a Johnson screen, and its edge is fixed on the side wall of the inner cavity of the vertical pipe section through an elastic member, thereby forming an annular baffle channel.

[0009] As another optimized scheme of the above microbubble-enhanced heavy oil atomization system, a baffle is inclinedly arranged on the side wall of the inner cavity of the vertical pipe section. The free end of the baffle extends into the baffle area after exceeding the gradually expanding part, and a diversion area for changing the flow direction of the gas-liquid mixed flow is formed between the baffle and the gradually expanding part.

[0010] As another optimized scheme of the above microbubble-enhanced heavy oil atomization system, a baffle is arranged between the baffle and the elastic broken flow plate, and the baffle and the baffle are located on both sides of the axis of the vertical pipe section. The baffle is fixed on the side wall of the inner cavity of the vertical pipe section, and its free end is inclined towards the oncoming flow direction and forms an acute angle with the inner wall of the vertical pipe section with the opening facing the oncoming flow direction.

[0011] As another optimized scheme of the above microbubble-enhanced heavy oil atomization system, a conical liquid guide cylinder is arranged on the side wall of the inner cavity of the vertical pipe section. The large-diameter end of the conical liquid guide cylinder is fixed to the vertical pipe section, and the small-diameter end is open and faces the elastic broken flow plate.

[0012] As another optimized scheme of the above microbubble-enhanced heavy oil atomization system, the atomizing nozzle has a cavity and a spray outlet. A spiral air guide plate is arranged around the inner side wall of the cavity. One side edge of the air guide plate is fixed to the inner wall of the cavity, and the other side is inclined upward and forms an air guide area with the side wall of the cavity with the opening facing the oncoming flow direction. The secondary air supply pipe extends into the air guide area, so that the continuous gas phase discharged by it collides and mixes with the gas-liquid mixed flow in the cavity during the spiral upward process along the air guide area.

[0013] As another optimized scheme of the above microbubble-enhanced heavy oil atomization system, the cavity is formed by splicing a cylindrical area and a conical area, the spray outlet is at the bottom of the conical area, the air guide plate is distributed on the inner side wall of the cylindrical area, and the secondary air supply pipe is located at a position in the air guide area close to the spray outlet.

[0014] A microbubble-enhanced heavy oil atomization method first mixes heavy oil with a gas phase so that the gas phase stably exists in the heavy oil in the form of microbubbles to form a gas-liquid emulsified phase oil, and then atomizes and sprays it out. The gas-liquid emulsified phase oil first undergoes baffle and collision, then conducts counter-flow mixing with the continuous phase gas, and then is atomized and sprayed out.

[0015] As an optimized scheme of the above microbubble-enhanced heavy oil atomization method, the baffle and collision of the gas-liquid emulsified phase oil means that during the flow process of the gas-liquid emulsified phase oil, the flow direction of some fluids is changed, and they intersect and collide with other parts of the fluids.

[0016] As another optimization scheme of the above microbubble-enhanced heavy oil atomization method, the countercurrent mixing with the continuous-phase gas means that the flow direction of the continuous-phase gas is non-parallel to the flow direction of the gas-liquid emulsified-phase oil.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1) Based on the conventional "formation of gas-liquid emulsified-phase oil + atomization by microbubbling heavy oil", the present invention introduces a secondary continuous-phase gas and makes the secondary continuous-phase gas perform countercurrent mixing with the gas-liquid emulsified-phase oil. Thus, during the process of atomizing and spraying the gas-liquid emulsified-phase oil, the microbubbles contained in the ejected micro-droplets can quickly undergo secondary explosion, further dispersing the size of the micro-droplets, and enabling the droplets once dispersed by the nozzle to be broken, refined, and dispersed again.

[0019] 2) By adding a buffer between the microbubble generator and the atomizing nozzle, the present invention enables the gas-liquid emulsified-phase oil not to be directly atomized and sprayed, but to enter the buffer. Since the buffer is L-shaped and has a gradually expanding part, a baffle area, and an elastic fragmentation plate inside, when the gas-liquid emulsified-phase oil enters the gradually expanding part, due to the gradually increasing inner diameter and being just at the corner, the overall flow direction of the gas-liquid emulsified-phase oil changes and adjusts to varying degrees, and a confluence occurs in the baffle area. Finally, it impacts on the elastic fragmentation plate, and the flow direction changes again. During the process of flow direction change and confluence, the distribution of microbubbles in the gas-liquid emulsified-phase oil and the thickness of the liquid film between microbubbles are changed. Then, it counteracts with the continuous-phase gas supplemented by the secondary gas supply pipe, changing the thickness of the liquid film between microbubbles, and during the atomizing and spraying process, the microbubbles undergo secondary explosion, thereby causing "secondary" dispersion of the micro-droplets and improving the dispersion effect of heavy oil.

[0020] 3) In order to further change the distribution characteristics of microbubbles in the gas-liquid emulsified-phase oil, a baffle plate with its top end extending into the baffle area is provided in the buffer of the present invention. By relying on the baffle plate, the flow state of part of the gas-liquid emulsified-phase oil is further changed, causing the gas-liquid emulsified-phase oil to impact itself; and a baffle plate is provided between the baffle plate and the elastic fragmentation plate, which can strengthen the internal impact effect of the gas-liquid emulsified-phase oil; in addition, the presence of the conical liquid guide cylinder can guide the gas-liquid emulsified-phase oil to impact on the fragmentation plate, thereby enhancing the vibration effect of the fragmentation plate and generating partial backflow. This part of the backflow deviates from the flow direction of the gas-liquid emulsified-phase oil, thereby improving the internal impact effect and promoting the secondary irregular distribution of microbubbles in the gas-liquid emulsified-phase oil.

[0021] 4) In order to improve the counter-flushing effect between the secondary continuous-phase gas and the gas-liquid emulsified-phase oil, an air guiding plate distributed in a spiral shape is arranged in the cavity of the atomizing nozzle. The secondary continuous-phase gas spirally ascends along the spiral groove formed by the air guiding plate and the inner wall of the cavity, and during this process, it counter-flushes and mixes with the gas-liquid emulsified-phase oil flowing from top to bottom. At the same time, the air guiding plate can also change the distribution of the gas-liquid emulsified-phase oil inside the nozzle, improving the mixing effect between the secondary continuous-phase gas and the gas-liquid emulsified-phase oil. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic structural diagram of the system of the present invention;

[0023] Figure 2 is a schematic structural diagram of the buffer in the present invention;

[0024] Figure 3 is an optimized schematic structural diagram of the atomizing nozzle in the present invention;

[0025] Figure 4 is a schematic structural diagram of the system of Comparative Example 1;

[0026] Figure 5 is a schematic structural diagram of the system of Comparative Example 2;

[0027] Figure 6 is a schematic structural diagram of the system of Comparative Example 3;

[0028] Reference numerals: 1, microbubble generator; 101, heavy oil pipeline; 102, gas-phase inlet pipeline; 2, first pipeline; 3, buffer; 301, horizontal pipe section; 302, vertical pipe section; 303, equal-diameter holes; 304, gradually expanding part; 305, baffle area; 306, baffle plate; 307, diversion area; 308, conical liquid guide cylinder; 309, elastic fragmentation plate; 3010, baffle plate; 4, second pipeline; 5, atomizing nozzle; 501, secondary air supply pipe; 502, cavity; 503, spray outlet; 504, air guiding plate; 505, air guiding area. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] The following further elaborates on the technical solutions of the present invention in combination with specific embodiments. For parts not clarified in the following embodiments of the present invention, such as the specific structure of the microbubble generator, parameters such as the ratio and flow rate of heavy oil and gas to form the gas-liquid emulsified-phase oil, parameters of the secondary air supply pipe for filling the continuous-phase gas, and other accessory structures of this system (structures for pressurizing heavy oil and gas phase), are all regarded as the prior art known or should be known to those skilled in the art.

[0030] Embodiment 1

[0031] A microbubble-enhanced heavy oil atomization system, as Figure 1As shown, it includes a microbubble generator 1 and an atomizing nozzle 5. For the microbubble generator 1 and the atomizing nozzle 5 in this embodiment, commercially available microbubble generator 1 and atomizing nozzle 5 can be directly used. Therefore, their structures and models will not be elaborated. Among them, heavy oil and gas phase are respectively transported into the microbubble generator 1 through the heavy oil pipeline 101 and the gas phase inlet pipeline 102 at the same time, and a gas-liquid emulsified phase oil is formed in the microbubble generator 1. The so-called gas-liquid emulsified phase oil means that microbubbles are evenly distributed in the oil phase to form a gas-liquid mixed phase. The size of the microbubbles is preferably below 30 microns. Then, it is ejected through the atomizing nozzle 5 to form atomized heavy oil micro-droplets, which can be applied to various reactors. The liquid outlet of the microbubble generator 1 is connected to the inlet of a buffer 3 through a first pipeline 2. The outlet of the buffer 3 is connected to the liquid inlet of the atomizing nozzle 5 through a second pipeline 4 perpendicular to the first pipeline 2. And the atomizing nozzle 5 is provided with a secondary gas supply pipe 501. Through the secondary gas supply pipe 501, continuous phase gas is continuously introduced into the atomizing nozzle 5, and the gas is made to produce a counterflush with the gas-liquid emulsified phase oil entering the atomizing nozzle 5. Then, it is ejected through the atomizing nozzle 5. The microbubbles contained in the small droplets burst internally and are refined to form micro-droplets;

[0032] As Figure 2 shown, the buffer 3 has an L-shaped hollow tubular structure, which is composed of a horizontal pipe section 301 connected to the first pipeline 2 and a vertical pipe section 302 connected to the second pipeline 4 integrated together. The horizontal pipe section 301 and the vertical pipe section 302 generally have the same outer diameter, and the axes of the two are perpendicular to each other. The horizontal pipe section 301 is provided with equal-diameter holes 303. The equal-diameter holes 303 are located at the center of the horizontal pipe section 301. One end of the equal-diameter holes 303 forms the opening of the buffer 3 and is connected to the first pipeline 2. The inner diameter of the other end gradually increases to form a gradually expanding part 304. In fact, the equal-diameter holes 303 and the gradually expanding part 304 constitute the continuous inner cavity of the horizontal pipe section 301. And the connection part between the gradually expanding part 304 and the inner cavity of the vertical pipe section 302 forms a baffle area 305. The baffle area 305 is actually the connection part of two mutually perpendicular pipe sections, and its inner cavity also has a right-angled corner. The inner cavity outlet of the vertical pipe section 302 forms the outlet of the buffer 3 and is connected to the second pipeline 4. An elastic fragmentation plate 309 is arranged in the inner cavity of the vertical pipe section 302. The elastic fragmentation plate 309 does not affect the outflow of the gas-liquid emulsified phase oil.

[0033] In this embodiment, the elastic broken flow plate 309 can be selected as a conventional metal plate, which can be drilled or not drilled. There is a gap between the edge of the metal plate and the inner wall of the vertical pipe section 302, and it is fixed on the inner wall of the vertical pipe section 302 through an elastic member, such as a spring; the elastic broken flow plate 309 is preferably a Johnson screen made of metal, and is also fixed on the inner wall of the vertical pipe section 302 through an elastic member. The metal wires forming the Johnson screen generally select conventional sizes, preferably 4.0 and 4.5 mm, and the width of the mesh holes on the surface generally does not exceed 1 mm. The shape of the Johnson screen is a circle identical to the inner cavity shape of the vertical pipe section 302, and the two are coaxial. And its edge is fixed on the side wall of the inner cavity of the vertical pipe section 302 through an elastic member, so as to form an annular baffle channel between its edge and the inner wall of the vertical pipe section 302. The width of the annular baffle channel, that is, the distance between the edge of the Johnson screen and the inner wall of the vertical pipe section 302, is generally 20-30% of the radius of the inner cavity of the vertical pipe section 302.

[0034] The above is the basic implementation manner of the present invention, and further improvements, optimizations and limitations can be made on this basis to obtain the following embodiments:

[0035] Embodiment 2

[0036] This embodiment is a further improvement of the buffer 3 on the basis of Embodiment 1. Its main structure is the same as that of Embodiment 1. The improvement lies in: as Figure 2 shown, a baffle plate 306 is inclinedly arranged on the side wall of the inner cavity of the vertical pipe section 302. The baffle plate 306 is preferably made of an alloy material resistant to erosion. It forms an angle of 40-60° with the inner wall of the vertical pipe section 302. The free end of the baffle plate 306 extends beyond the extension line of the side wall of the gradually expanding part 304 and extends into the baffle area 305. That is to say, there is a gap between the connection point of the baffle plate 306 and the vertical pipe section 302 and the intersection of the vertical pipe section 302 and the horizontal pipe section 301, and there is also a gap between the free end of the baffle plate 306 and the other side wall of the inner cavity of the vertical pipe section 302. That is, the baffle plate 306 cannot close the inner cavity of the vertical pipe section 302. In practice, the baffle plate 306 is actually an arc-shaped plate, and its arc-shaped side is arranged close to the side wall of the inner cavity of the vertical pipe section 302. The projection of the straight side in the radial direction of the vertical pipe section 302 does not exceed the radius of the vertical pipe section 302, generally 20-40% of the inner diameter of the inner cavity of the vertical pipe section 302, and forms a diversion area 307 for changing the flow direction of the gas-liquid mixed flow with the gradually expanding part 304;

[0037] In addition, in this embodiment, a baffle plate 3010 can also be arranged between the baffle plate 306 and the elastic broken flow plate 309, as Figure 2As shown, the baffle 3010 is preferably made of an erosion-resistant alloy material. It forms an angle of 20 - 60° with the inner wall of the vertical pipe section 302. The baffle 3010 and the flow baffle 306 are located on both sides of the axis of the vertical pipe section 302. The projections of the free ends of the baffle 3010 and the flow baffle 306 in the radial direction of the vertical pipe section 302 do not touch. The baffle 3010 is fixed on the side wall of the inner cavity of the vertical pipe section 302, and its free end is inclined towards the oncoming flow direction. The so-called oncoming flow direction refers to the flow direction of the gas-liquid mixed flow, and forms an acute angle with the inner wall of the vertical pipe section 302 with the opening facing the oncoming flow direction, so that part of the gas-liquid mixed flow forms a backflow within this acute angle. In practice, the baffle 3010 is actually an arc-shaped plate, whose arc-shaped side is arranged along the side wall of the inner cavity of the vertical pipe section 302, and the projection of the straight side in the radial direction of the vertical pipe section 302 does not exceed the radius of the vertical pipe section 302, generally being 20 - 30% of the inner diameter of the vertical pipe section 302;

[0038] In addition, in this embodiment, a conical liquid guide cylinder 308 can also be arranged on the side wall of the inner cavity of the vertical pipe section 302, as Figure 2 shown. The conical liquid guide cylinder 308 is preferably a cylindrical structure with openings at both ends made of an erosion-resistant alloy material. Its generatrix forms an angle of 120 - 160° with the inner wall of the vertical pipe section 302. The large-diameter end of the conical liquid guide cylinder 308 is fixed to the vertical pipe section 302, and the small-diameter end is open and faces the elastic fragmentation baffle 309, so as to guide the gas-liquid mixed flow to impact on the elastic fragmentation baffle 309. In practice, the diameter of the opening at the small-diameter end of the conical liquid guide cylinder 308 is generally 60 - 90% of the diameter of the elastic fragmentation baffle 309.

[0039] Embodiment 3

[0040] This embodiment is a further improvement of the atomizing nozzle 5 based on Embodiment 1. Its main structure is the same as that of Embodiment 1. The improvement lies in that: the atomizing nozzle 5 can adopt an existing atomizing nozzle, but only a secondary air supply pipe 501 needs to be added to the atomizing nozzle, preferably adopting the following structure, as Figure 3As shown, it has a cavity 502 and a jet outlet 503. The cavity 502 is used to communicate with the second pipeline 4, allowing the gas-liquid mixed flow to enter the cavity 502 and be ejected through the jet outlet 503. The cavity 502 is generally a cylindrical cavity. A spiral air guide plate 504 is arranged around the inner side wall of the cavity 502. One side edge of the air guide plate 504 is fixed to the inner wall of the cavity 502, and the other side is inclined upward, forming an air guide area 505 with an opening facing the oncoming flow direction with the cavity side wall. In practice, the air guide plate 504 is a spiral plate. When viewed from the horizontal direction, the projection of the air guide plate 504 in the vertical direction is an inclined straight plate, and the acute angle formed between it and the inner wall of the cavity 502 is generally 20 - 60°. The distance between its edge and the inner wall of the cavity 502 is generally 10 - 20% of the diameter of the cavity 502. The finally formed air guide area 505 is actually a spiral groove, and the depth of the groove is generally greater than the intake port of the secondary gas supply pipe 501 for introducing continuous phase gas. In practice, the secondary gas supply pipe 501 is an inclined hole opened on the inner side wall of the cavity 502, and the diameter of the inclined hole is less than half of the groove depth. The secondary gas supply pipe 501 extends into the air guide area 505. The secondary gas supply pipe 501 is at one end of the air guide area 505 close to the jet outlet 503. The axis of the secondary gas supply pipe 501 can be perpendicular to the axis of the cavity 502, or can form a certain acute or obtuse angle with the axis of the cavity 502. Preferably, the secondary gas supply pipe 501 is perpendicular to the axis of the cavity 502 and injects continuous phase gas along the tangent direction of the cavity 502. At the same time, the injection direction of the gas is opposite to the spiral direction of the air guide plate 504, so that the gas moves along the spiral air guide plate 504 in the direction away from the jet outlet 503, and when the discharged continuous gas phase spirally ascends along the air guide area 505, it impacts and mixes with the gas-liquid mixed flow in the cavity 502;

[0041] In this embodiment, the cavity 502 is an integral structure formed by splicing a hollow cylindrical area and a conical area. The central axes of the cylindrical area and the conical area overlap. The diameter of the cylindrical area is equal to the large diameter end of the conical area, and one end is connected to the large diameter end of the conical area, and the other end is connected to the second pipeline 4, so that the gas-liquid mixed flow enters the cavity 502. The jet outlet 503 is at the bottom tip position of the conical area. The air guide plate 504 is distributed on the inner side wall of the cylindrical area, and both ends of the air guide plate 504 do not extend beyond the upper and lower end faces of the cylindrical area. The secondary gas supply pipe 501 is at a position in the air guide area 505 close to the jet outlet 503 and is within the angle formed by the air guide plate 504 and the side wall of the cylindrical area.

[0042] Embodiment 4

[0043] A method for enhancing the atomization of heavy oil with microbubbles. First, mix heavy oil with a gas phase. Generally, an existing microbubble generator is used. The mixing ratio and the selection of the gas phase are adjusted according to different reactions that the heavy oil participates in. The purpose is only to make the gas phase stably exist in the heavy oil in the form of microbubbles, forming a gas-liquid emulsified phase oil. Then, spray it through an atomizing nozzle into various reactors. The gas-liquid emulsified phase oil first undergoes baffle flow and collision. Generally, pipelines, containers, etc. are used. When the gas-liquid emulsified phase oil passes through these pipelines and containers, it collides with the auxiliary structures or side walls inside the pipelines and containers to generate baffle flow. Then, it undergoes counter-flow mixing with the continuous phase gas. Counter-flow mixing with the continuous phase gas means introducing the continuous phase gas into the gas-liquid emulsified phase oil, and the flow direction of the continuous phase gas is opposite to that of the gas-liquid emulsified phase oil. The properties, flow rate, flow rate, and other parameters of the continuous phase gas need to be adjusted according to the specific type of reaction. However, its flow rate should preferably not exceed half of the flow rate of the gas-liquid emulsified phase oil. The inlet position of the continuous phase gas can generally be introduced into the pipeline or perform counter-flow mixing in the atomizing nozzle, and then be atomized and sprayed through the atomizing nozzle.

[0044] In this embodiment, the baffle flow and collision of the gas-liquid emulsified phase oil mean that during the flow process of the gas-liquid emulsified phase oil, the flow direction of some fluids is changed, and they intersect and collide with other parts of the fluids.

[0045] In this embodiment, the counter-flow mixing with the continuous phase gas means that the flow direction of the continuous phase gas is non-parallel to that of the gas-liquid emulsified phase oil. Generally, they are opposite, or the continuous phase gas is introduced at a certain angle away from the spray outlet.

[0046] To verify the specific effects of the present invention, the following comparative experiments were carried out:

[0047] Experimental content:

[0048] The properties of the selected heavy oil are as follows: density is 0.978 g / cm 3 (20 °C), kinematic viscosity is 3396 mm 2 / s (80 °C), 859.6 mm 2 / s (100 °C), the residual carbon content is 3.6%, the H content is 12.53%, the S content is 0.22%, and the other irrelevant parameters are not listed;

[0049] Using hydrogen as the gas phase, with a microbubble generator, hydrogen is mixed with heavy oil to form a gas-liquid emulsified phase oil. The selected microbubble generator makes the size of the microbubbles not exceed 30 microns; the ratio of hydrogen to heavy oil is 1:1 - 1:50;

[0050] The diameter of the spray hole in the atomizing nozzle is 0.8 mm. The gas-liquid emulsified oil formed by heavy oil and hydrogen is sprayed out through the atomizing nozzle at a pressure of 3 MPa, and the size of the sprayed small droplets is detected;

[0051] Comparative Example 1

[0052] As Figure 4 shown, the heavy oil and hydrogen as above are formed into gas-liquid emulsified oil in the microbubble generator 1 at a ratio of 50:1, and then sent into the atomizing nozzle 5 for spraying, and the size of the sprayed small droplets is detected, with the maximum being 56 microns;

[0053] Experimental Example 1

[0054] As Figure 1 shown, the heavy oil and hydrogen as above are first formed into gas-liquid emulsified oil in the microbubble generator 1 at a ratio of 50:1, and then passed into the buffer 3 for treatment, and then passed into the atomizing nozzle 5 for spraying. At the same time, continuous-phase hydrogen is passed into the atomizing nozzle 5, and the passing ratio of hydrogen is 1:2. The size of the sprayed small droplets is detected, with the maximum being 22 microns;

[0055] In this embodiment, the microbubble generator 1 and the atomizing nozzle 5 are the same as those in Comparative Example 1;

[0056] The structure of the buffer 3 is:

[0057] The buffer 3 has an L-shaped hollow tubular structure, which is formed by integrating a horizontal pipe section 301 communicating with the first pipeline 2 and a vertical pipe section 302 communicating with the second pipeline 4. The horizontal pipe section 301 and the vertical pipe section 302 generally have the same outer diameter, and their axes are perpendicular to each other. The horizontal pipe section 301 has an equal-diameter hole 303 at its center. The equal-diameter hole 303 has a diameter of 1 cm and is located at the center of the horizontal pipe section 301. One end of the equal-diameter hole 303 forms an opening of the buffer 3 and communicates with the first pipeline 2. The inner diameter of the other end gradually increases to form a tapered expansion part 304. The tapered expansion part 304 is conical, with a maximum diameter of 3 cm. A baffle area 305 is formed at the connection between the tapered expansion part 304 and the inner cavity of the vertical pipe section 302. The baffle area 305 is actually the connection of two mutually perpendicular pipe sections, and its inner cavity also has a right-angled corner. The inner cavity outlet of the vertical pipe section 302 forms an outlet of the buffer 3 and communicates with the second pipeline 4. The inner diameter of the vertical pipe section 302 is 3 cm. An elastic crushing plate 309 is arranged in the inner cavity of the vertical pipe section 302. The elastic crushing plate 309 does not affect the outflow of the gas-liquid emulsified phase oil; the elastic crushing plate 309 is a Johnson screen made of metal and is also fixed on the inner wall of the vertical pipe section 302 through elastic parts. The metal wire forming the Johnson screen is 4.0 mm, and the width of the mesh on the surface is 0.5 mm. The shape of the Johnson screen is circular and the same as the shape of the inner cavity of the vertical pipe section 302, and the two are coaxial. And its edge is fixed on the side wall of the inner cavity of the vertical pipe section 302 through elastic parts, so that an annular baffle channel is formed between its edge and the inner wall of the vertical pipe section 302. The width of the annular baffle channel, that is, the distance between the edge of the Johnson screen and the inner wall of the vertical pipe section 302 is 4 mm.

[0058] Experimental Example 2

[0059] As Figure 1 shown, the above heavy oil and hydrogen are first formed into a gas-liquid emulsified phase oil in the microbubble generator 1 according to a ratio of 40:1, and then passed into the buffer 3 for treatment and then sprayed out through the atomizing nozzle 5. At the same time, continuous-phase hydrogen is passed into the atomizing nozzle 5, and the passing ratio of hydrogen is 1:2. The size of the sprayed small droplets is detected, and the maximum is 16 microns;

[0060] In this embodiment, the microbubble generator 1 and the atomizing nozzle 5 are the same as those in Comparative Example 1;

[0061] The structure of the buffer 3 is:

[0062] The buffer 3 is in an L-shaped hollow tubular structure, which is formed by integrating a horizontal pipe section 301 communicating with the first pipeline 2 and a vertical pipe section 302 communicating with the second pipeline 4. The horizontal pipe section 301 and the vertical pipe section 302 generally have the same outer diameter, and the axes of the two are perpendicular to each other. An equal-diameter hole 303 is provided in the horizontal pipe section 301. The equal-diameter hole 303 is at the center of the horizontal pipe section 301, with a diameter of 1 cm. One end of the equal-diameter hole 303 forms an opening of the buffer 3 and communicates with the first pipeline 2. The inner diameter of the other end gradually increases to form a gradually expanding portion 304. The gradually expanding portion 304 is conical, with a maximum diameter of 3 cm. A baffle area 305 is formed at the connection of the gradually expanding portion 304 and the inner cavity of the vertical pipe section 302. The baffle area 305 is actually the connection of two mutually perpendicular pipe sections, and its inner cavity also has a right-angled corner. The inner cavity outlet of the vertical pipe section 302 forms an outlet of the buffer 3 and communicates with the second pipeline 4. The diameter of the inner cavity of the vertical pipe section 302 is 3 cm. An elastic crushing plate 309 is arranged in the inner cavity of the vertical pipe section 302, and the elastic crushing plate 309 does not affect the outflow of the gas-liquid emulsified phase oil; the elastic crushing plate 309 is a Johnson screen made of metal material and is also fixed on the inner wall of the vertical pipe section 302 through an elastic member. The metal wire forming the Johnson screen is 4.0 mm, and the width of the mesh holes on the surface is 0.5 mm. The shape of the Johnson screen is a circle identical to the shape of the inner cavity of the vertical pipe section 302, and the two are coaxial. And its edge is fixed on the side wall of the inner cavity of the vertical pipe section 302 through an elastic member, so as to form an annular baffle channel between its edge and the inner wall of the vertical pipe section 302. The width of the annular baffle channel, that is, the distance between the edge of the Johnson screen and the inner wall of the vertical pipe section 302 is 4 mm;

[0063] A baffle plate 306 is inclinedly arranged on the side wall of the inner cavity of the vertical pipe section 302. The baffle plate 306 is made of an erosion-resistant alloy material, and it forms an angle of 40° with the inner wall of the vertical pipe section 302. The free end of the baffle plate 306 extends beyond the side wall extension line of the gradually expanding portion 304 and then extends into the baffle area 305. The baffle plate 306 is actually an arc-shaped plate, and its arc-shaped side is attached to the side wall of the inner cavity of the vertical pipe section 302. The projection of the straight side in the radial direction of the vertical pipe section 302 does not exceed the radius of the vertical pipe section 302, which is 40% of the diameter of the inner cavity of the vertical pipe section 302, and a diversion area 307 for changing the flow direction of the gas-liquid mixed flow is formed between the baffle plate 306 and the gradually expanding portion 304.

[0064] Experimental Example 3

[0065] As Figure 1 shown, the above heavy oil and hydrogen are first formed into a gas-liquid emulsified phase oil in the microbubble generator 1 according to a ratio of 30:1, and then passed into the buffer 3 for treatment, and then passed into the atomizing nozzle 5 for spraying. At the same time, continuous-phase hydrogen is passed into the atomizing nozzle 5, and the passing ratio of hydrogen is 1:1. The size of the sprayed small droplets is detected, and the maximum is 13 microns;

[0066] In this embodiment, the microbubble generator 1 and the atomizing nozzle 5 are the same as those in Comparative Example 1;

[0067] The structure of the buffer 3 is as follows:

[0068] The buffer 3 is in an L-shaped hollow tubular structure, which is formed by connecting a horizontal pipe section 301 communicating with the first pipeline 2 and a vertical pipe section 302 communicating with the second pipeline 4 into one body. The horizontal pipe section 301 and the vertical pipe section 302 generally have the same outer diameter, and the axes of the two are perpendicular to each other. The horizontal pipe section 301 has an equal-diameter hole 303 in the center. The equal-diameter hole 303 has a diameter of 1 cm. One end of the equal-diameter hole 303 forms the opening of the buffer 3 and communicates with the first pipeline 2. The inner diameter of the other end gradually increases to form a tapered expansion part 304. The tapered expansion part 304 is conical, with a maximum diameter of 3 cm. And a baffle area 305 is formed at the connection of the tapered expansion part 304 and the inner cavity of the vertical pipe section 302. The baffle area 305 is actually the connection of two mutually perpendicular pipe sections, and its inner cavity also has a right-angle corner. The inner cavity outlet of the vertical pipe section 302 forms the outlet of the buffer 3 and communicates with the second pipeline 4. The diameter of the inner cavity of the vertical pipe section 302 is 3 cm. An elastic crushing plate 309 is arranged in the inner cavity of the vertical pipe section 302, and the elastic crushing plate 309 does not affect the outflow of the gas-liquid emulsified phase oil; the elastic crushing plate 309 is a Johnson screen made of metal material, and is also fixed on the inner wall of the vertical pipe section 302 through an elastic member. The metal wire forming the Johnson screen is 4.0 mm, and the width of the mesh on the surface is 0.5 mm. The shape of the Johnson screen is a circle same as the shape of the inner cavity of the vertical pipe section 302, and the two are coaxial, and its edge is fixed on the side wall of the inner cavity of the vertical pipe section 302 through an elastic member, so as to form an annular baffle channel between its edge and the inner wall of the vertical pipe section 302. The width of the annular baffle channel, that is, the distance between the edge of the Johnson screen and the inner wall of the vertical pipe section 302 is 4 mm;

[0069] A baffle plate 3010 is arranged between the baffle 306 and the elastic crushing plate 309. As Figure 2 shown, the baffle plate 3010 is made of an erosion-resistant alloy material, forms an angle of 40° with the inner wall of the vertical pipe section 302, and the baffle plate 3010 and the baffle 306 are on both sides of the axis of the vertical pipe section 302. The projections of the free ends of the baffle plate 3010 and the baffle 306 in the radial direction of the vertical pipe section 302 do not contact. The baffle plate 3010 is fixed on the side wall of the inner cavity of the vertical pipe section 302, and the free end is inclined towards the oncoming flow direction, and forms an acute angle opening towards the oncoming flow direction with the inner wall of the vertical pipe section 302. The baffle plate 3010 is actually an arc-shaped plate, and its arc-shaped side is arranged along the side wall of the inner cavity of the vertical pipe section 302. The projection of the straight side in the radial direction of the vertical pipe section 302 does not exceed the radius of the vertical pipe section 302, generally 30% of the inner cavity diameter of the vertical pipe section 302.

[0070] Comparative Example 2

[0071] As Figure 5 shown, the above heavy oil and hydrogen are first formed into a gas-liquid emulsified phase oil in the microbubble generator 1 according to a ratio of 20:1, and then passed into the buffer 3 for treatment, and then passed into the atomizing nozzle 5 for spraying. The size of the sprayed small droplets is detected, and the maximum is 43 microns;

[0072] In this embodiment, the microbubble generator 1 and the atomizing nozzle 5 are the same as those in Comparative Example 1, and the structure of the buffer 3 is the same as that in Example 1.

[0073] Comparative Example 3

[0074] As Figure 6 shown, the above heavy oil and hydrogen are first formed into a gas-liquid emulsified phase oil in the microbubble generator 1 according to a ratio of 20:1, passed into the atomizing nozzle 5 for spraying, and at the same time, continuous-phase hydrogen is passed into the atomizing nozzle 5. The passing ratio of hydrogen is the same as that in Experimental Example 1. The size of the sprayed small droplets is detected, and the maximum is 52 microns;

[0075] In this embodiment, the microbubble generator 1 and the atomizing nozzle 5 are the same as those in Comparative Example 1.

[0076] Experimental conclusion:

[0077] It can be seen from the above comparative experiments that under the same process parameter conditions, for the gas-liquid emulsified phase oil formed by mixing heavy oil and microbubbles and directly sprayed out by the atomizing nozzle, the maximum size of the formed micro-droplets is 56 microns; while after passing into the buffer chamber first and then atomizing and spraying after counteracting with the secondary continuous-phase gas, the size of the micro-droplets can be well controlled and reduced to 22 microns and below. That is to say, by the method of the present invention, the size of the micro-droplets of heavy oil can be effectively reduced and better dispersed.

[0078] It can be seen from Comparative Example 2 and Comparative Example 3 that simply using the buffer 3 and secondary gas injection can also refine the size of the micro-droplets to a certain extent, but the refining effect is not ideal.

Claims

1. A microbubble-enhanced heavy oil atomization system, comprising a microbubble generator (1) and an atomizing nozzle (5), wherein, Heavy oil and gas phase form a gas-liquid emulsified phase oil in a microbubble generator (1), and then are ejected through an atomizing nozzle (5). It is characterized in that the microbubble generator (1) is connected to the inlet of a buffer (3) through a first pipeline (2), the outlet of the buffer (3) is connected to the atomizing nozzle (5) through a second pipeline (4) perpendicular to the first pipeline (2), and the atomizing nozzle (5) is provided with a secondary air supply pipe (501). The buffer (3) is in an L shape and is composed of a horizontal pipe section (301) and a vertical pipe section (302). The horizontal pipe section (301) is provided with equal-diameter holes (303). One end of the equal-diameter hole (303) has an inner diameter that gradually increases to form a gradually expanding part (304). A baffle area (305) is formed at the connection of the gradually expanding part (304) and the inner cavity of the vertical pipe section (302). An elastic fragmentation plate (309) is arranged in the inner cavity of the vertical pipe section (302).

2. The microbubble enhanced heavy oil atomization system according to claim 1, wherein: The elastic fragmentation plate (309) is a Johnson screen, and its edge is fixed to the side wall of the inner cavity of the vertical pipe section (302) through an elastic member, thereby forming an annular baffle channel.

3. The microbubble-enhanced heavy oil atomization system according to claim 1, characterized in that: A baffle plate (306) is inclinedly arranged on the side wall of the inner cavity of the vertical pipe section (302). The free end of the baffle plate (306) extends into the baffle area (305) after exceeding the gradually expanding part (304), and a diversion area (307) for changing the flow direction of the gas-liquid mixed flow is formed between the baffle plate (306) and the gradually expanding part (304).

4. The microbubble enhanced heavy oil atomization system according to claim 3, wherein: A baffle plate (3010) is arranged between the baffle plate (306) and the elastic fragmentation plate (309). The baffle plate (3010) and the baffle plate (306) are located on both sides of the axis of the vertical pipe section (302). The baffle plate (3010) is fixed to the side wall of the inner cavity of the vertical pipe section (302), and its free end is inclined towards the oncoming flow direction and forms an acute angle with the inner wall of the vertical pipe section (302) with the opening facing the oncoming flow direction.

5. A microbubble-enhanced heavy oil atomization system according to claim 1, characterized in that: A conical liquid guide cylinder (308) is arranged on the side wall of the inner cavity of the vertical pipe section (302). The large-diameter end of the conical liquid guide cylinder (308) is fixed to the vertical pipe section (302), and the small-diameter end is open and faces the elastic fragmentation plate (309).

6. The microbubble-enhanced heavy oil atomization system according to claim 1, wherein: The atomizing nozzle (5) has a cavity (502) and a spray outlet (503). A spiral air guide plate (504) is arranged around the inner side wall of the cavity (502). One side edge of the air guide plate (504) is fixed to the inner wall of the cavity (502), and the other side is inclined upwards and forms an air guide area (505) with the cavity side wall with the opening facing the oncoming flow direction. The secondary air supply pipe (501) extends into the air guide area (505), so that the continuous gas phase discharged therefrom collides and mixes with the gas-liquid mixed flow in the cavity (502) during the spiral upward process along the air guide area (505).

7. The microbubble enhanced heavy oil atomization system according to claim 6, characterized in that: The cavity (502) is formed by splicing a cylindrical area and a conical area. The spray outlet (503) is at the bottom of the conical area. The air guide plate (504) is distributed on the inner side wall of the cylindrical area, and the secondary air supply pipe (501) is located at a position in the air guide area (505) close to the spray outlet (503).

8. A method for enhancing heavy oil atomization with microbubbles. First, mix heavy oil with a gas phase so that the gas phase stably exists in the heavy oil in the form of microbubbles to form a gas-liquid emulsified phase oil, and then atomize and eject it. It is characterized in that: The gas-liquid emulsified phase oil first undergoes baffle and collision, then conducts counter-flow mixing with the continuous phase gas, and then is atomized and ejected.

9. The microbubble-enhanced heavy oil atomization method according to claim 8, characterized in that: The baffle and collision of the gas-liquid emulsion phase oil mean that during the flow of the gas-liquid emulsion phase oil, the flow direction of some of the fluid is changed, and it intersects and collides with other parts of the fluid.

10. The microbubble-enhanced heavy oil atomization method according to claim 8, characterized in that: The counter-flow mixing with the continuous phase gas means that the flow direction of the continuous phase gas is not parallel to the flow direction of the gas-liquid emulsion phase oil.

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