Underwater counter-rotating type helical blade multiphase mixed transportation booster pump

Abstract

The invention discloses an underwater counter-rotating type helical blade multiphase mixed transportation booster pump. The multiphase mixed transportation booster pump comprises a first shell, an inner second shell, a plurality of first compression mixing units, a plurality of second compression mixing units, a first protective cover, a second protective cover, a homogenizer, a flow guide cone, a first pump shaft connected with the first compression mixing units, a second pump shaft connected with the second compression mixing units and a welding pump inlet flange. And a pump outlet flange. Efficient mixing and pressurization of gas-liquid two-phase media are achieved through the unique flow channel and the counter-rotating impeller. The trumpet-cone-shaped first flow channel and the spiral groove-shaped third flow channel optimize the flow field stability of the gas-liquid initial mixing stage and the gas-liquid output stage correspondingly, continuous collision and mixing of media are promoted, and the uniformity is improved. The double compression units which are arranged in a disrotatory mode can recycle energy to do work for the second time, the design of the multi-stage impeller is matched, and the more obvious supercharging effect is achieved under the same energy consumption.

Description

Technical Field

[0001] This invention relates to the technical field of underwater oil and gas extraction equipment, and in particular to an underwater counter-rotating helical blade multiphase mixed transport booster pump. Background Technology

[0002] With my country's rapid economic development, the demand for oil continues to rise, and the production of onshore oil and gas fields can no longer meet domestic demand. To reduce dependence on imported oil, the development of offshore oil and gas fields has become an important direction. The ocean, especially the mid-to-deep sea area, contains abundant oil and gas resources, but its development faces many unique challenges. In particular, due to geological conditions and oil and gas formation mechanisms, the products extracted from the mid-to-deep sea area are mostly gas-liquid two-phase mixtures. Furthermore, as the extraction depth increases, the proportion of the gas phase in the total flow of the mixture also increases. This high gas content mixture poses a severe challenge to underwater oil and gas transportation equipment.

[0003] Currently, in the operation of underwater multiphase mixed-transfer booster pumps in China, gas-liquid separation is highly likely to occur inside the pump body when transporting mixed media with a high gas content. Once gas-liquid separation occurs, it will lead to a series of serious adverse consequences. First, gas-liquid separation causes a sharp rise in the pump's internal operating temperature. Excessive temperature not only accelerates the aging and wear of equipment components but may also pose safety hazards. Second, it causes a significant decrease in pump efficiency, resulting in the pump consuming more energy to transport the same amount of media, increasing operating costs. Third, it causes a sharp reduction in pump head, affecting the distance and pressure of media transport, failing to meet actual production needs. Furthermore, it can cause unstable pump operation, generating vibration and noise, and shortening the equipment's service life. In severe cases, gas-liquid separation can even hinder the normal operation of the pump, such as causing pump burnout, leading to equipment damage, significant economic losses, and production interruptions.

[0004] Therefore, as the development of offshore oil and gas fields continues to advance, in order to achieve efficient, stable, and safe oil and gas transportation and improve the development benefits of offshore oil and gas fields, it is urgent to develop an underwater counter-rotating helical blade multiphase mixed transport booster pump that can efficiently transport mixed oil and gas media. Summary of the Invention

[0005] This invention provides an underwater counter-rotating helical blade multiphase mixing booster pump to solve the gas-liquid separation phenomenon caused by insufficient mixing inside the pump body during the transportation of high gas content mixed media in existing underwater multiphase mixing booster pumps, as well as a series of technical problems such as pump temperature rise, efficiency reduction, head reduction, unstable operation, and even pump burnout.

[0006] In view of the above technical problems, embodiments of the present invention provide an underwater counter-rotating helical blade multiphase mixing booster pump, comprising a first housing, a second housing built inside the first housing, a plurality of first compression mixing units disposed between the first housing and the second housing, a plurality of second compression mixing units disposed within the second housing, a first protective cover connected to the top of the first housing, a second protective cover connected to the bottom of the first housing, a homogenizer, a guide cone, a first pump shaft connected to the first compression mixing units, a second pump shaft connected to the second compression mixing units, a pump inlet flange welded to the first housing, and a pump outlet flange welded to the second housing; the first compression mixing units and the second compression mixing units perform counter-rotating motions in opposite directions at the same time, for progressively pressurizing and mixing the oil-gas multiphase mixed medium; the first pump shaft and the second pump shaft also perform counter-rotating motions in opposite directions at the same time;

[0007] The gap between the second protective cover and the homogenizer forms a first flow channel, the gap between the homogenizer and the guide cone forms a second flow channel, a third flow channel communicating with the second compression mixing unit is provided on the second housing, and a fourth flow channel is provided in the hollow part of the first pump shaft;

[0008] The oil and gas multiphase mixed medium is transported to different pipeline systems via a transport path consisting of the pump inlet flange, the homogenizer, the guide cone, the second flow channel, the fourth flow channel, the third flow channel, and the pump outlet flange connected in sequence.

[0009] Optionally, the first compression mixing unit includes a first impeller mounted on the first pump shaft and a first guide vane mounted on the first housing. The first pump shaft is connected to a first explosion-proof motor via a first coupling. The first explosion-proof motor is installed inside the first protective cover.

[0010] The second compression mixing unit includes a second impeller mounted on a second pump shaft and a second guide vane mounted on a second housing. The second pump shaft is connected to a second explosion-proof motor via a second coupling.

[0011] The first explosion-proof motor and the second explosion-proof motor rotate in opposite directions at the same time;

[0012] The first compression mixing unit is connected to the fourth flow channel and to the pump inlet flange, and the second compression mixing unit is connected to the third flow channel and to the pump outlet flange.

[0013] Optionally, the underwater counter-rotating helical blade multiphase mixed-transport booster pump further includes a first single-row bearing and a first double-row bearing mounted on the first pump shaft and used to support the shaft center position of the first pump shaft, and a first mechanical seal is also installed on the first pump shaft;

[0014] The underwater counter-rotating helical blade multiphase mixed-transport booster pump also includes a second single-row bearing and a second double-row bearing mounted on the second pump shaft to support the shaft center position of the second pump shaft, and a second mechanical seal is also installed on the second pump shaft.

[0015] Optionally, the first impeller and the second impeller have the same structure. The first impeller includes blades, a hub, an impeller inner diameter, and a first keyway. The blades are disposed on the hub. The size of the impeller inner diameter is adapted to the outer diameter of the first pump shaft. The first impeller is fixedly installed on the first pump shaft through the first keyway.

[0016] Optionally, the first guide vane and the second guide vane have the same structure. The first guide vane includes a guide vane outer diameter, a second keyway, a guide vane flange, and a guide vane inner diameter. The guide vane flange is disposed in the annular groove formed by the guide vane outer diameter and the guide vane inner diameter. The size of the guide vane outer diameter is adapted to the size of the first housing, and the first guide vane is fixedly installed on the first housing through the second keyway.

[0017] Optionally, the homogenizer is assembled and welded from a first connecting flange, a first porous tube, and a second porous tube fixedly connected to the first housing. The first porous tube and the second porous tube are connected from the outside to the inside to form a double-layer porous tube structure with an annular cavity. The first porous tube is provided with a plurality of first openings, and the second porous tube is provided with a plurality of second openings. The distribution density of the first openings is less than the distribution density of the second openings, and the diameter of the first openings is greater than the diameter of the second openings.

[0018] Optionally, the flow guide cone is welded together from a second connecting flange, a flow guide shroud, and a base plate that are fixedly connected to the second housing. The flow guide shroud and the base plate are connected to form a protective inner cavity for installing the second explosion-proof motor. The flow guide shroud includes a flow guide arc inlet section near the base plate and a flow guide extension section near the second connecting flange. The extension line of the flow guide arc inlet section and the flow guide extension section are tangent at an angle of 4°.

[0019] Optionally, the annular horn-shaped conical flow channel formed between the second protective cover and the homogenizer is the first flow channel, the angle between the second protective cover and the inclined surface of the homogenizer is 3°, and the angle between the bottom surface of the second protective cover and the bottom surface of the homogenizer is 70°;

[0020] The second flow channel is an annular columnar flow channel, and the angle between the homogenizer and the inclined surface of the guide cone is 1°.

[0021] Optionally, the third flow channel is a rectangular spiral groove type flow channel; the fourth flow channel consists of 8 flow channel holes evenly distributed in a ring array in the hollow part of the first pump shaft, with horn cones on both sides of the flow channel holes, a cylindrical body in the middle of the flow channel holes, and the cone angle of the flow channel holes is 30°.

[0022] Optionally, the preset speeds of the first explosion-proof motor and the second explosion-proof motor are equal or unequal; the number of the first compression mixing unit and the second compression mixing unit are equal or unequal.

[0023] This invention achieves efficient mixing and pressurization of gas-liquid two-phase media through a unique flow channel design and counter-rotating impeller structure. The annular horn-cone type first flow channel and the rectangular spiral groove type third flow channel design optimize the flow field stability during the initial mixing and output stages of the gas-liquid mixture, respectively, allowing the medium to continuously collide, break up, and mix during flow, significantly improving mixing uniformity. Simultaneously, the counter-rotating operation mode of the dual compression mixing unit can recover some energy for secondary work. Combined with the multi-stage impeller design, a more significant pressurization effect is achieved with the same energy consumption, making it particularly suitable for high-pressure conditions such as deep-sea mining and oil and gas transportation. The optimized flow channel structure effectively suppresses unstable phenomena such as vortices and cavitation. The 30° cone-angle fourth flow channel orifice and guide structure stabilize the fluid flow field and reduce energy loss; the synergistic effect of the double-layer porous pipe homogenizer and the guide cone further eliminates dead water zones and flow turbulence. These designs not only reduce equipment vibration and noise, but also extend the service life of key components. Combined with the safety protection of explosion-proof motors, they ensure long-term stable operation of the equipment in extreme environments such as high temperature, high pressure, and flammable and explosive conditions, thereby improving overall reliability.

[0024] This invention, through a variable speed control mechanism and modular unit design, endows the equipment with extremely strong environmental adaptability. The two explosion-proof motors can independently adjust their speeds, allowing for both fixed single-side impeller speeds for simplified control and dynamic matching of impeller speeds on both sides, precisely responding to changes in medium viscosity, flow rate fluctuations, and other factors. Furthermore, the number of compression and mixing units can be increased or decreased according to actual needs, with flexible stage adjustments. This not only meets the economic requirements of low-flow-rate conditions but also addresses high-flow-rate and high-pressure differential scenarios by increasing the number of stages, significantly broadening the equipment's application range. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1This is a schematic diagram of the overall structure of an underwater counter-rotating helical blade multiphase mixed-transport booster pump according to an embodiment of the present invention;

[0027] Figure 2 This is a cross-sectional view of a portion of the structure of an underwater counter-rotating helical blade multiphase mixed-transport booster pump according to an embodiment of the present invention;

[0028] Figure 3 This is a schematic diagram of the structure of the first impeller in one embodiment of the present invention;

[0029] Figure 4 This is a schematic diagram of the structure of the first guide vane in one embodiment of the present invention;

[0030] Figure 5 This is a schematic diagram of the structure of the first compression mixing unit composed of the first impeller and the first guide vane in one embodiment of the present invention;

[0031] Figure 6 This is a schematic diagram of the homogenizer in one embodiment of the present invention;

[0032] Figure 7 This is a schematic diagram of the flow guide cone in one embodiment of the present invention;

[0033] Figure 8 This is a schematic diagram of the structure of the first flow channel in one embodiment of the present invention;

[0034] Figure 9 This is a schematic diagram of the structure of the second flow channel in one embodiment of the present invention;

[0035] Figure 10 This is a schematic diagram of the structure of the third flow channel according to an embodiment of the present invention;

[0036] Figure 11 This is a schematic diagram of the fourth flow channel in one embodiment of the present invention.

[0037] The reference numerals in the accompanying drawings are as follows:

[0038] 1-First housing, 11-First protective cover, 12-Second protective cover, 13-Pump inlet flange, 14-Pump outlet flange, 2-Second housing, 3-Hydraulizer, 301-First connecting flange, 302-First perforated pipe, 3021-First opening, 303-Second perforated pipe, 3031-Second opening, 4-Guide cone, 401-Second connecting flange, 402-Guide cover, 403-Base plate, 404-Guide arc inlet section, 405-Guide extension section, 406-Protective inner cavity, 5-First pump shaft, 6-Second pump shaft, 7-First flow channel, 8-Second flow channel, 9-Third flow channel, 10-Fourth flow channel 101-Flow channel hole, 15-First impeller, 1501-Blade, 1502-Hub, 1503-Impeller inner diameter, 1504-First keyway, 16-First guide vane, 1601-Guide vane outer diameter, 1602-Second keyway, 1603-Guide vane flange, 1604-Guide vane inner diameter, 17-Second impeller, 18-Second guide vane, 19-First coupling, 20-First explosion-proof motor, 21-Second coupling, 22-Second explosion-proof motor, 23-First single-row bearing, 24-First double-row bearing, 25-First mechanical seal, 26-Second single-row bearing, 27-Second double-row bearing, 28-Second mechanical seal. Detailed Implementation

[0039] To make the technical problems solved, the technical solutions, and the beneficial effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0040] In the description of this invention, it should be understood that the terms "longitudinal," "radial," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0041] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0042] like Figures 1 to 11 As shown, an embodiment of the present invention provides an underwater counter-rotating helical blade multiphase mixing booster pump, including a first housing 1, a second housing 2 built inside the first housing 1, a plurality of first compression mixing units disposed between the first housing 1 and the second housing 2, a plurality of second compression mixing units disposed inside the second housing 2, a first protective cover 11 connected to the top of the first housing 1, a second protective cover 12 connected to the bottom of the first housing 1, a homogenizer 3, a guide cone 4, a first pump shaft 5 connected to the first compression mixing units, a second pump shaft 6 connected to the second compression mixing units, a pump inlet flange 13 welded to the first housing 1, and a pump outlet flange 14 welded to the second housing 2; the first compression mixing units and the second compression mixing units perform counter-rotating motions in opposite directions at the same time, for progressively pressurizing and mixing the oil-gas multiphase mixed medium; the first pump shaft 5 and the second pump shaft 6 also perform counter-rotating motions in opposite directions at the same time.

[0043] The gap between the second protective cover 12 and the homogenizer 3 forms a first flow channel 7, the gap between the homogenizer 3 and the guide cone 4 forms a second flow channel 8, the second housing 2 is provided with a third flow channel 9 that communicates with the second compression mixing unit, and the hollow part of the first pump shaft 5 is provided with a fourth flow channel 10.

[0044] The oil-gas multiphase mixed medium is transported to different pipeline systems via a conveying path formed by the sequential connection of the pump inlet flange 13, the homogenizer 3, the guide cone 4, the second flow channel 8, the fourth flow channel 10, the third flow channel 9, and the pump outlet flange 14. Understandably, since the first housing 1 and the second housing 2 can adopt an open structure, they are not sensitive to sand or other solid particles, and have significant advantages when handling fluids containing solid particles. The first protective cover 11 serves to protect the first explosion-proof motor 20, and is equipped with lifting lugs for easy lifting, installation, transportation, and maintenance.

[0045] In this invention, the oil-gas multiphase mixed medium first enters the pump through the pump inlet flange 13. As the first explosion-proof motor 20 and the second explosion-proof motor 22 drive the first impeller 15 and the second impeller 17 to rotate respectively, a negative pressure zone is formed, and the mixed medium is drawn into the first flow channel 7, which is composed of the second protective cover 12 and the homogenizer 3. Next, the medium enters the homogenizer 3, where the gas-liquid two-phase mixed medium undergoes preliminary mixing through violent impact, effectively breaking up large gas masses to prevent gas-liquid separation in subsequent flow channels.

[0046] After initial mixing, the gas-liquid mixture is then guided by the guide cone 4 and smoothly enters the first compression and mixing unit, which is composed of the first impeller 15 and the first guide vane 16, through the second flow channel 8. The first impeller 15 is driven to rotate by the first explosion-proof motor 20 through the first pump shaft 5. The mixing medium is accelerated and gains kinetic energy. When it passes through the stationary first guide vane 16, the speed decreases and the kinetic energy is converted into pressure energy. At this time, the gas and liquid phases are mixed more thoroughly and initially pressurized step by step.

[0047] The mixed medium processed by the first compression unit enters the second compression unit, which consists of the second impeller 17 and the second guide vane 18, through the fourth flow channel 10. Since the first impeller 15 and the second impeller 17 rotate in opposite directions, they form a counter-rotating structure. For example, when the first explosion-proof motor 20 runs clockwise, the first impeller 15 also rotates clockwise, and the gas-liquid mixed medium is mixed and compressed step by step from bottom to top. Meanwhile, the second impeller 17 rotates counterclockwise under the drive of the second explosion-proof motor 22, which not only recovers some of the energy at the outlet of the first impeller 15, but also performs secondary work on the fluid. The medium is pressurized step by step to the expected value in the second compression unit, thereby significantly improving the overall efficiency of the booster pump.

[0048] Finally, after the mixed medium has undergone multi-stage pressurization and reached the expected pressure value, it is transported to the pump outlet flange 14 through the third flow channel 9 and further distributed to different pipeline systems. Compared with traditional multiphase flow pumps, this invention effectively solves the gas-liquid separation problem under high gas content, thus exhibiting better flow performance and pressurization efficiency when processing mixed media with high gas content.

[0049] In one embodiment, such as Figures 1 to 2As shown, the first compression mixing unit includes a first impeller 15 mounted on the first pump shaft 5 and a first guide vane 16 mounted on the first housing 1. The first pump shaft 5 is connected to a first explosion-proof motor 20 via a first coupling 19; the first explosion-proof motor 20 is installed inside the first protective cover 11. The second compression mixing unit includes a second impeller 17 mounted on a second pump shaft 6 and a second guide vane 18 mounted on the second housing 2. The second pump shaft 6 is connected to a second explosion-proof motor 22 via a second coupling 21. The first explosion-proof motor 20 and the second explosion-proof motor 22 rotate in opposite directions at the same time. The first compression mixing unit communicates with the fourth flow channel 10 and is connected to the pump inlet flange 13, while the second compression mixing unit communicates with the third flow channel 9 and is connected to the pump outlet flange 14. Understandably, the first compression mixing unit and the second compression mixing unit are driven by the first explosion-proof motor 20 and the second explosion-proof motor 22, and the two motors rotate in opposite directions to form a counter-rotating structure. The first explosion-proof motor 20 can also rotate counterclockwise, but the second explosion-proof motor 22 must rotate clockwise. The rotation directions of the two motors cannot be the same at the same time; that is, they must rotate in opposite directions. This design is not a simple parallel operation, but rather achieves energy recovery and secondary work through counterclockwise rotation: after the first compression unit performs work on the medium, the second compression unit recovers its outlet energy in a counterclockwise manner and further pressurizes the fluid, thereby significantly improving the overall efficiency of the pump, which is significantly higher than that of traditional multiphase flow pumps. The two-stage units work in series in counterclockwise rotation, gradually pressurizing the medium to the expected value, while ensuring sufficient gas-liquid homogeneity through multi-stage mixing, avoiding separation at high gas content.

[0050] Furthermore, the first explosion-proof motor 20 can drive the first impeller 15 mounted on the first pump shaft 5 to rotate, providing power for the rotation of the first impeller 15. The second explosion-proof motor 22 can drive the second impeller 17 mounted on the second pump shaft to rotate, providing power for the rotation of the second impeller 17. Cooling fluid lines (not shown) are provided on the outer sides of both the first explosion-proof motor 20 and the second explosion-proof motor 22 to cool and dissipate heat from the motors. The first coupling 19 and the second coupling 21, as mechanical transmission components, transmit torque and speed to the two motors respectively. Buffer and shock-absorbing components (not shown) are installed on them to reduce vibration and impact during operation, extend the service life of the equipment, and compensate for misalignment or displacement of the two shafts, improving the operational stability of the underwater counter-rotating helical blade multiphase mixed-transport booster pump.

[0051] In one embodiment, such as Figures 1 to 2As shown, the underwater counter-rotating helical blade multiphase mixing booster pump further includes a first single-row bearing 23 and a first double-row bearing 24 mounted on the first pump shaft 5 to support the center position of the first pump shaft 5. A first mechanical seal 25 is also installed on the first pump shaft 5. The underwater counter-rotating helical blade multiphase mixing booster pump further includes a second single-row bearing 26 and a second double-row bearing 27 mounted on the second pump shaft 6 to support the center position of the second pump shaft 6. A second mechanical seal 28 is also installed on the second pump shaft 6. Understandably, the first single-row bearing 23 supports the rotation of the first pump shaft 5, maintaining the center position of the shaft. The first mechanical seal 25 prevents leakage of the mixed medium, maintaining the flow of the mixed medium within the underwater counter-rotating helical blade multiphase mixing booster pump chamber. The functions of the second single-row bearing 26 and the second mechanical seal 28 are similar and will not be described further here.

[0052] In one embodiment, such as Figure 1 and Figure 3 As shown, the first impeller 15 and the second impeller 17 have the same structure. The first impeller 15 includes blades 1501, a hub 1502, an impeller inner diameter 1503, and a first keyway 1504. The blades 1501 are disposed on the hub 1502. The size of the impeller inner diameter 1503 is adapted to the outer diameter of the first pump shaft 5, and the first impeller 15 is fixedly installed on the first pump shaft 5 through the first keyway 1504. The installation structure of the second impeller 17 is the same as that of the first impeller 15, and will not be described again here. It can be understood that the blades 1501 are disposed on the hub 1502, the impeller inner diameter 1503 is adapted to the outer diameter of the first pump shaft 5, and is fixedly installed on the first pump shaft 5 through the first keyway 1504, ensuring that the first impeller 15 stably transmits power when rotating with the pump shaft. The core function of the first impeller 15 is to convert mechanical energy into the kinetic energy of the medium through rotation: when the medium enters the first impeller 15, the blades 1501 drive the medium to accelerate, forming a low-pressure zone, which, combined with the inlet pressure difference, continuously draws in fluid; this design not only increases the medium flow rate, but also promotes the initial mixing of gas and liquid, laying the foundation for subsequent pressurization.

[0053] In one embodiment, such as Figure 1 , Figure 4 and Figure 5As shown, the first guide vane 16 and the second guide vane 18 have the same structure. The first guide vane 16 includes a guide vane outer diameter 1601, a second keyway 1602, a guide vane flange 1603, and a guide vane inner diameter 1604. The guide vane flange 1603 is disposed in the annular groove formed by the guide vane outer diameter 1601 and the guide vane inner diameter 1604. The size of the guide vane outer diameter 1601 is adapted to the size of the first housing 1, and the first guide vane 16 is fixedly installed on the first housing 1 through the second keyway 1602. The installation structure of the second guide vane 18 is the same as that of the first guide vane 16, and will not be described again here.

[0054] Understandably, the first guide vane 16 is mounted on the first housing 1 and remains stationary with the first housing 1. When the mixing medium flows through the rotating first impeller 15, the medium is accelerated and gains sufficient kinetic energy under the action of the centrifugal force of the first impeller 15. Subsequently, the high-speed flowing mixing medium enters the area of ​​the first guide vane 16. Under the guiding and damping action of the first guide vane 16, the flow velocity gradually decreases, and part of the kinetic energy is efficiently converted into pressure energy, thereby achieving the initial pressurization of the mixing medium and the full mixing of the gas and liquid phases.

[0055] The second guide vane 18 is fixedly installed on the second housing 2 and remains stationary with the second housing 2. After the mixing medium enters the second impeller 17, it is accelerated again by the rotation of the second impeller 17 and gains kinetic energy. When the accelerated medium flows through the stationary second guide vane 18, the flow velocity decreases, and the kinetic energy is further converted into pressure energy. Each time the medium flows through a compression mixing unit (i.e., each second compression mixing unit is considered a booster stage), it gains a portion of energy replenishment, eventually accumulating to reach the expected booster value.

[0056] Furthermore, understandably, during the rotation of the first impeller 15, the medium is centrifugally thrown outwards along the surface of the blades 1501, efficiently converting mechanical energy into the kinetic energy of the liquid. At this time, a low-pressure zone is formed in the central area of ​​the first impeller 15, which is formed by the blades 1501 and the hub 1502, creating a pressure difference with the liquid surface of the external liquid source. When this pressure difference overcomes the flow resistance of the fluid in the pipes and channels, the liquid in the liquid source will be continuously and stably drawn into the interior of the first impeller 15 through the flow channels, realizing the continuous transport of the medium.

[0057] In the first guide vane 16 structure, guide vane fins 1603 are uniformly distributed in the annular groove between the outer diameter 1601 and the inner diameter 1604 of the guide vane, forming independent fin structures between adjacent guide vane fins 1603. When the medium carrying kinetic energy flows from the rotating first impeller 15 into the stationary guide vane fin 1603 fin, the medium velocity decreases rapidly due to the obstruction and guiding effect of the guide vane fins 1603, and part of its kinetic energy is converted into static pressure energy, thereby achieving medium pressurization. In addition, under the specific flow field environment formed by the fins of the first guide vane 16, the gas phase and liquid phase in the medium fully contact and mix under the action of eddies, further improving the mixing uniformity and transmission stability of the multiphase medium.

[0058] In one embodiment, such as Figure 1 and Figure 6 As shown, the homogenizer 3 is assembled and welded from a first connecting flange 301, a first porous tube 302, and a second porous tube 303, which are fixedly connected to the first housing 1. The first porous tube 302 and the second porous tube 303 are connected from the outside to the inside to form a double-layer porous tube structure with an annular cavity. The first porous tube 302 is provided with a plurality of first openings 3021, and the second porous tube 303 is provided with a plurality of second openings 3031. The distribution density of the first openings 3021 is less than that of the second openings 3031, and the diameter of the first openings 3021 is greater than that of the second openings 3031. Understandably, when the mixed medium enters the first flow channel 7 formed by the second protective cover 12 and the homogenizer through the pump inlet flange 13, the liquid phase and the gas phase exhibit distinctly different flow paths: the liquid phase flows downward along the flow channel wall under the action of gravity, and turns back upward after reaching the bottom; the gas phase converges towards the central area through the staggered openings on the first porous tube 302 and the second porous tube 303. Because the flow directions of the two phases intersect perpendicularly, a violent collision occurs at the moment of convergence, and larger gas masses are immediately broken into smaller bubbles. Due to the double-layer porous tube structure of the homogenizer 3, the gas-liquid contact area is significantly expanded. When a larger gas mass enters the first opening 3021 of the first porous tube 302, it is initially broken into smaller bubbles under the combined action of tube wall constraint and liquid phase shear force. These bubbles continue to collide and disperse with the liquid phase in the annular cavity between the two porous tubes, forming a more uniform gas-liquid mixture. Subsequently, the mixed medium enters the second porous tube 303, and through the secondary segmentation effect of the second opening 3031, the bubble size is further refined, ultimately completing multi-stage collisions, breaking, and mixing with the liquid phase in the second flow channel 8. This repeated action not only effectively breaks up the slug flow entering the system but also achieves preliminary uniform mixing of the gas and liquid phases, providing stable and homogeneous medium conditions for subsequent processes.

[0059] In one embodiment, such as Figure 1 and Figure 7As shown, the flow guide cone 4 is welded together from a second connecting flange 401, a flow guide shroud 402, and a base plate 403, which are fixedly connected to the second housing 2. The flow guide shroud 402 and the base plate 403 are connected to form a protective inner cavity 406 for installing the second explosion-proof motor 22. The flow guide shroud 402 includes a flow guide arc inlet section 404 near the base plate 403 and a flow guide extension section 405 near the second connecting flange 401. The extension line of the flow guide arc inlet section 404 and the flow guide extension section 405 are tangent at an angle of 4°. Understandably, when the mixed medium flows through the second flow channel 8 jointly constructed by the homogenizer 3 and the guide cone 4, the liquid phase fluid dominates at the bottom near the guide arc inlet section 404. This guide arc inlet section 404 adopts an arc cone surface design. This unique geometric structure can efficiently eliminate vortices generated during fluid movement, stabilize the flow state, effectively reduce cavitation, and completely remove dead water zones within the flow channel, thereby significantly improving pump operating efficiency. The guide extension section 405, which connects to the guide arc inlet section 404 at a 4° angle, further optimizes the fluid path: the gas-liquid mixed medium flows smoothly from the plane around the cone to the first impeller 15 along a regular conical slope, causing the flow cross-section to expand uniformly along the medium flow direction, and the liquid inlet velocity to increase steadily, completely eliminating turbulence in the medium flow and significantly reducing energy loss.

[0060] Furthermore, at the guide arc inlet section 404, the liquid medium flow remains highly stable due to the precise control of the arc cone structure, resulting in a significant increase in flow velocity. During the upward flow, an effective negative pressure zone is formed, actively inducing the uniform mixing of the gas phase into the liquid phase. This gas-liquid induced mixing mechanism not only strengthens the anti-cavitation cavitation capability at the pump inlet but also makes the flow field distribution more uniform through rectification. The fluid achieves uniform distribution before entering the first impeller 15, significantly reducing fluid non-uniformity and pulsation, providing stable and homogeneous fluid conditions for the efficient operation of the first impeller 15, thereby comprehensively improving the operating efficiency and reliability of the pump system.

[0061] In one embodiment, such as Figure 1 , Figure 8 , Figure 9 As shown, the annular horn-shaped conical flow channel formed between the second protective cover 12 and the homogenizer 3 is the first flow channel 7. The angle between the inclined surface of the second protective cover 12 and the homogenizer 3 is 3°, and the angle between the bottom surface of the second protective cover 12 and the bottom surface of the homogenizer 3 is 70°. The second flow channel 8 is an annular columnar flow channel, and the angle between the inclined surface of the homogenizer 3 and the guide cone 4 is 1°.

[0062] Understandably, designing the first flow channel 7 as an annular horn-shaped conical flow channel allows the liquid medium to collide and mix more efficiently with the gas medium flowing through the first flow channel 7 towards the opening of the homogenizer 3 and converging towards the center when it flows towards the bottom of the second protective cover 12. The 3° angle cleverly slows down the gas flow velocity, while the 70° angle accelerates the liquid flow, allowing the rapidly flowing liquid phase to meet the slowly moving gas mass, making the gas mass easier to break up and thus promoting thorough gas-liquid mixing.

[0063] Understandably, the second flow channel 8 is designed as an annular cylindrical flow channel. A large amount of liquid medium rushing in from the guide arc inlet section 404 enters the second flow channel 8 at a high velocity, colliding violently and deeply mixing with the mixed medium treated by the homogenizer 3. During this process, the rising liquid flow can also induce the uniform incorporation of the gas phase into the liquid phase, effectively suppressing cavitation at the pump inlet. At the same time, this design plays a role in rectifying and stabilizing the flow field, making the fluid distribution more uniform before entering the impeller, greatly reducing the non-uniformity and pulsation of the fluid, and providing a strong guarantee for the efficient and stable operation of the pump.

[0064] In one embodiment, such as Figures 10 to 11 As shown, the third flow channel 9 is disposed on the second housing 2 and is a rectangular spiral groove type flow channel; the fourth flow channel 10 consists of eight flow channel holes 101 evenly distributed in a ring array in the hollow part of the first pump shaft 5. The two sides of each flow channel hole 101 are provided with horn-shaped cones, and the center of each flow channel hole 101 is provided with a cylindrical body. The cone angle of each flow channel hole 101 is 30°. Understandably, the mixed medium, after being fully acted upon by the last stage second impeller 17, flows smoothly out along the rectangular spiral groove type third flow channel 9 under the precise drive of the second pump shaft 6, finally reaching the pump outlet flange 14. The unique rectangular spiral groove structure of this third flow channel 9 is like a stable track tailor-made for gas-liquid mixed media, effectively enhancing the stability of the flow field, ensuring that the medium maintains an orderly state during flow, and reducing energy loss caused by flow field turbulence. Meanwhile, the first pump shaft 5 and the second pump shaft 6 form a counter-rotating motion, providing a strong guarantee for the stable delivery and efficient pressurization of the medium fluid. The two ends of the flow channel hole 101 are carefully designed with a 30° cone angle. This ingenious design is like laying a buffer zone for the fluid flow, which can better stabilize the fluid flow field and avoid violent fluctuations in the fluid during the flow process. The second compression and mixing unit, composed of the second impeller 17, cleverly recovers part of the energy from the outlet of the first compression and mixing unit (i.e., the fourth flow channel 10) composed of the first impeller 15 in a counter-rotating manner, and performs secondary work on the medium fluid. This not only achieves efficient energy utilization, but also significantly improves the overall efficiency of the underwater counter-rotating helical blade multiphase mixing and booster pump, enabling it to exhibit excellent performance under complex multiphase mixing and transport conditions.

[0065] In one embodiment, such as Figures 1 to 9 As shown, the preset speeds of the first explosion-proof motor 20 and the second explosion-proof motor 22 are equal or unequal; the number of the first compression mixing unit and the second compression mixing unit are equal or unequal. Understandably, the preset speeds of the first explosion-proof motor 20 and the second explosion-proof motor 22 can be flexibly configured according to actual working conditions. They can be set to the same value to achieve stable coordinated operation, or set to different values ​​to adapt to complex and changing conveying requirements. In specific implementation, the speed of the first impeller 15 driven by the first explosion-proof motor 20 can be fixed, while the speed of the second impeller 17 driven by the second explosion-proof motor 22 can be dynamically adjusted; or the opposite strategy can be adopted, fixing the speed of the second impeller 17 while adjusting the speed of the first impeller 15; or the speeds of the impellers driven by the two explosion-proof motors can be kept variable. This multi-mode speed control mechanism gives the underwater counter-rotating helical blade multiphase mixing booster pump extremely strong environmental adaptability, enabling precise matching of different media characteristics, flow rates, pressures, and changes in working conditions.

[0066] The number of the first compression mixing unit formed by the first impeller 15 and the first guide vane 16, and the number of the second compression mixing unit formed by the second impeller 17 and the second guide vane 18, must be determined through professional calculations combined with specific operating conditions. Each impeller corresponds to one stage of compression unit (one first impeller 15 corresponds to one stage of the first compression mixing unit), and increasing the number of stages will significantly improve the boosting effect. This modular design ensures the economy of the equipment under simple operating conditions, while also meeting the needs of complex operating conditions such as high pressure and large flow by increasing or decreasing the number of stages, fully demonstrating the high flexibility of this multiphase mixed-transport booster pump in terms of structural design and functional implementation.

[0067] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. An underwater counter-rotating propeller multiphase mixed-flow booster pump, characterized in that, The first shell (1), the second shell (2) built-in the first shell (1), a plurality of first compression mixing units arranged between the first shell (1) and the second shell (2), a plurality of second compression mixing units arranged in the second shell (2), the first protective cover (11) connected to the top of the first shell (1), the second protective cover (12) connected to the bottom of the first shell (1), the homogenizer (3), the flow cone (4), the first pump shaft (5) connected to the first compression mixing unit, the second pump shaft (6) connected to the second compression mixing unit, the pump inlet flange (13) welded on the first shell (1), and the pump outlet flange (14) welded on the second shell (2); the first compression mixing unit and the second compression mixing unit make opposite direction rotation movement at the same time, for step-by-step pressurization and mixing of oil-gas multiphase mixed medium; The first pump shaft (5) and the second pump shaft (6) also make opposite direction rotation movement at the same time; The gap between the second protective cover (12) and the homogenizer (3) forms the first flow channel (7), the gap between the homogenizer (3) and the flow cone (4) forms the second flow channel (8), the third flow channel (9) is arranged on the second shell (2) and communicates with the second compression mixing unit, and the hollow part of the first pump shaft (5) is provided with the fourth flow channel (10); The oil-gas multiphase mixed medium is sequentially communicated through the conveying path composed of the pump inlet flange (13), the homogenizer (3), the flow cone (4), the second flow channel (8), the fourth flow channel (10), the third flow channel (9) and the pump outlet flange (14), so as to be conveyed to different pipeline systems.

2. The underwater contra-rotating propeller multi-phase mixed-flow booster pump according to claim 1, characterized in that, The first compression mixing unit comprises the first impeller (15) mounted on the first pump shaft (5) and the first guide vane (16) mounted on the first shell (1), and the first pump shaft (5) is connected to the first explosion-proof motor (20) through the first coupling (19); the first explosion-proof motor (20) is mounted in the first protective cover (11); The second compression mixing unit comprises the second impeller (17) mounted on the second pump shaft (6) and the second guide vane (18) mounted on the second shell (2), and the second pump shaft (6) is connected to the second explosion-proof motor (22) through the second coupling (21); The first explosion-proof motor (20) and the second explosion-proof motor (22) rotate in opposite directions at the same time; The first compression mixing unit communicates with the fourth flow channel (10) and communicates with the pump inlet flange (13), and the second compression mixing unit communicates with the third flow channel (9) and communicates with the pump outlet flange (14).

3. The underwater contra-rotating propeller multiphase mixed-flow booster pump according to claim 2, characterized in that, The first single-row bearing (23) and the first double-row bearing (24) are mounted on the first pump shaft (5) and used for supporting the central position of the first pump shaft (5), and the first mechanical seal (25) is also mounted on the first pump shaft (5). Also included are a second single-row bearing (26) and a second double-row bearing (27) mounted on the second pump shaft (6) and used to support the center position of the second pump shaft (6), and a second mechanical seal (28) mounted on the second pump shaft (6).

4. The underwater contra-rotating propeller multi-phase mixed flow booster pump according to claim 2, characterized in that, The first impeller (15) and the second impeller (17) are identical in structure, the first impeller (15) comprises blades (1501), a hub (1502), an impeller inner diameter (1503) and a first key groove (1504), the blades (1501) are arranged on the hub (1502), the size of the impeller inner diameter (1503) is adapted to the outer diameter of the first pump shaft (5), and the first impeller (15) is fixedly installed on the first pump shaft (5) through the first key groove (1504).

5. The underwater contra-rotating propeller multi-phase mixed-flow booster pump according to claim 4, characterized in that, The first guide vane (16) and the second guide vane (18) are identical in structure, the first guide vane (16) comprises a guide vane outer diameter (1601), a second key groove (1602), a guide vane shank (1603) and a guide vane inner diameter (1604), the guide vane shank (1603) is arranged in the annular groove formed by the guide vane outer diameter (1601) and the guide vane inner diameter (1604), the size of the guide vane outer diameter (1601) is adapted to the size of the first casing (1), and the first guide vane (16) is fixedly installed on the first casing (1) through the second key groove (1602).

6. The underwater contra-rotating propeller multi-phase mixed flow booster pump according to claim 2, characterized in that, The homogenizer (3) is composed of a first connecting flange (301) fixedly connected to the first casing (1), a first porous pipe (302) and a second porous pipe (303), the first porous pipe (302) and the second porous pipe (303) are connected from outside to inside to form a double-layer porous pipe structure with an annular cavity, a plurality of first openings (3021) are arranged on the first porous pipe (302), a plurality of second openings (3031) are arranged on the second porous pipe (303), the distribution density of the first openings (3021) is smaller than the distribution density of the second openings (3031), and the diameter of the first openings (3021) is larger than the diameter of the second openings (3031).

7. The underwater contra-rotating propeller multi-phase mixed-flow booster pump according to claim 5, characterized in that, The flow guide cone (4) is composed of a second connecting flange (401) fixedly connected to the second casing (2), a flow guide cover (402) and a bottom plate (403), the flow guide cover (402) and the bottom plate (403) are connected to enclose a protective inner cavity (406) for mounting the second explosion-proof motor (22), the flow guide cover (402) comprises a flow guide circular arc inlet section (404) close to the bottom plate (403) and a flow guide extension section (405) close to the second connecting flange (401), and the tangent angle between the extension line of the flow guide circular arc inlet section (404) and the flow guide extension section (405) is 4°.

8. The underwater contra-rotating propeller multi-phase mixed-flow booster pump according to claim 7, characterized in that, The annular horn conical flow channel formed between the second protective cover (12) and the homogenizer (3) is the first flow channel (7), the included angle between the second protective cover (12) and the inclined surface of the homogenizer (3) is 3°, and the included angle between the bottom surface of the second protective cover (12) and the bottom surface of the homogenizer (3) is 70°. The second flow channel (8) is an annular columnar flow channel, and the included angle between the homogenizer (3) and the tapered inclined surface of the flow guide cone (4) is 1°.

9. The underwater contra-rotating propeller multi-phase mixed-flow booster pump according to claim 7, characterized in that, The third flow channel (9) is a rectangular spiral groove flow channel; the fourth flow channel (10) is composed of 8 flow channel holes (101) uniformly distributed in the hollow part of the first pump shaft (5) in the form of an annular array, horn conical bodies are arranged on both sides of the flow channel hole (101), a cylindrical body is arranged in the middle of the flow channel hole (101), and the taper angle of the flow channel hole (101) is 30°.

10. The underwater contra-rotating propeller multi-phase mixed-flow booster pump according to claim 2, characterized in that, The preset rotating speeds of the first explosion-proof motor (20) and the second explosion-proof motor (22) are equal / not equal; the number of first compression mixing units and second compression mixing units is equal / not equal.

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