A multiphase flow gas phase aggregation inhibiting type mixed flow pump impeller composite structure

Abstract

The application discloses a multiphase flow gas phase gathering inhibition type mixed delivery pump impeller composite structure, relates to the field of fluid machinery, and comprises a hub, a plurality of blades which are uniformly distributed around the central axis of the hub, and a wheel cover which is connected to the outer edge of the blade, wherein: the inlet edge of the blade is located between the hub and the wheel cover, and the outlet edge extends to the outer edge of the wheel cover; a circular arc chamfer with a radius of 2mm-5mm is arranged on the front edge of the inlet edge of the blade, and the minimum gap between the inlet edge of the blade and the surface of the hub is 1.5% to 3.0% of the inlet diameter of the impeller; the impeller composite structure can intervene in the whole process from the source of gas phase gathering to the separation in the flow channel in multiple dimensions through the synergistic effect of the unique three-dimensional profile design of the blade, the inlet pre-rotation guide structure and the dynamic vortex generator in the flow channel, effectively inhibits the gas-liquid two-phase separation, and further improves the stability and efficiency of multiphase flow delivery.

Description

Technical Field

[0001] This invention belongs to the field of fluid machinery, specifically a multiphase flow gas phase aggregation suppression type mixed pump impeller composite structure. Background Technology

[0002] Multiphase pumps are core equipment in oilfield, shale gas extraction, and deep-sea oil and gas transportation. Their function is to directly pressurize and transport multiphase mixtures of oil, gas, water, and sand produced from the wellhead, thereby avoiding the construction of large separation facilities and multiple pipelines, resulting in significant economic and environmental benefits. However, multiphase pumps, especially their core working component—the impeller—always face a critical technical bottleneck when transporting gas-liquid two-phase media: flow instability caused by phase separation.

[0003] In the strong centrifugal force field generated by the high-speed rotation of the impeller, the gaseous medium, with a density much lower than that of the liquid, will violently accumulate in the low-pressure area at the center of the impeller (such as the hub surface and the root of the blade pressure surface), while the liquid phase will be thrown towards the high-pressure area at the outer edge of the impeller. This phase separation phenomenon based on density difference can lead to a series of serious consequences:

[0004] Gas lock and performance degradation: The accumulated gas phase forms large gas masses or continuous gas locks in the flow channel, reducing the effective flow area and causing a sharp drop in pump head and efficiency. In some cases, surge or flow interruption may occur when the gas content is slightly high, making the entire conveying system unable to operate stably.

[0005] Unstable flow field and vibration noise: Non-uniform and intermittent gas flow can cause strong pressure pulsations, which are transmitted to the pump casing and bearings, resulting in increased unit vibration and noise, threatening the safety and lifespan of the equipment.

[0006] Localized erosion and wear: The liquid phase concentrates at the impeller outlet and guide vane inlet. When the medium contains sand or other solid particles, it will cause localized high-speed erosion of the flow components, significantly shortening the equipment maintenance cycle.

[0007] Existing technologies have made some attempts to solve the above problems, mainly including:

[0008] Macroscopic flow channel optimization: This involves adjusting the blade placement angle, wrap angle, or flow channel width to attempt to improve flow conditions. However, this method has limited effectiveness in suppressing phase separation dominated by density differences, often resulting in trade-offs and making it difficult to maintain high efficiency and stability across a wide range of operating conditions.

[0009] According to the inventor's search, the currently disclosed prior art includes the following:

[0010] Reference document 1: CN108397417A discloses an impeller structure for a mixed-transport pump. It includes a moving impeller and its blades, and a stationary impeller and its blades. The stationary impeller blades have an S-shaped profile. The inlet direction of the stationary impeller blades is the same as the outlet direction of the moving impeller blades. The outlet angle of the stationary impeller blades is 90 degrees. The bending direction of the inlet section of the stationary impeller blades is opposite to that of the outlet section. The length of the inlet section is one-third of the total blade length. The profile has a smooth, gently transitioning structure. The inlet and outlet thicknesses are less than the thickness of the middle section of the blade. The inlet position of the stationary impeller blades is ahead of the stationary impeller.

[0011] At the blade outlet position, there are 7 blades, evenly arranged along the circumference of the stationary impeller. This invention designs the stationary impeller blade profile as S-shaped, and the inlet direction of the stationary impeller blades is the same as the outlet direction of the moving impeller blades. This reduces vortices and hydraulic losses within the stationary impeller of the mixed-transfer pump, improves the pressurization performance of the stationary impeller, and increases the efficiency of the mixed-transfer pump.

[0012] Reference document 2: CN120292117A discloses an oil-gas mixed-transfer pump impeller tip leakage flow suppression structure, design method, and oil-gas mixed-transfer pump. The leakage flow suppression structure includes impeller blades, the top of which has a groove. Furthermore, the projection of the groove onto a plane perpendicular to the blade's rib line is trapezoidal. This invention's trapezoidal groove structure at the impeller blade tip effectively disperses vortices and turbulence on the impeller surface through precise fluid control, reducing fluid impact and wear on the impeller, thereby significantly reducing the vibration level of the mixed-transfer pump and extending the impeller's service life.

[0013] Reference document 3: CN101603530B discloses a vortex-type gas-liquid multiphase mixing pump, which consists of a moving vortex disk, a stationary vortex disk, a support body, a crank shaft, and a small crank anti-rotation mechanism. Two moving and stationary vortex disks with the same profile rotate relative to each other by 90° and are offset by a certain distance before being inserted together to form multiple working chambers. Driven by the crank shaft and constrained by the small crank anti-rotation mechanism, the moving vortex disk revolves and translates with the stationary vortex disk, forming a periodically changing working chamber volume, thereby realizing the intake, compression, and discharge of gas-liquid media. Both the moving and stationary scroll plates have a section of scroll teeth with variable meshing clearance formed by an involute base circle of varying diameter. During operation, there is a meshing clearance, which creates a pressure relief channel from the compression chamber to the outlet. During the pressurization process, a small amount of gas-liquid medium leaks internally from the compression chamber to the outlet through this channel, achieving random unloading of the liquid phase compression. This solves the problem of sudden pressure increase and liquid hammer that easily occurs when pressurizing and transporting mixed gas-liquid media when the liquid content is high.

[0014] Although existing improvement schemes can improve problems such as airlock, vibration, or sudden pressure increases by optimizing impeller blade profiles (such as the S-shaped stationary impeller blades in Comparative Document 1), suppressing tip leakage flow (such as the trapezoidal groove structure in Comparative Document 2), or using vortex structures to achieve gas-liquid pressurization and unloading (such as the dynamic and static vortex disk design in Comparative Document 3), some shortcomings still exist, as illustrated by the following examples:

[0015] Comparative document 1 (CN108397417A) only reduces vortex and hydraulic loss through the S-shaped profile design of the stationary impeller blades, but does not propose a solution to the problem of gas accumulation in the impeller channel. It cannot suppress the channel blockage and performance deterioration caused by gas accumulation. Especially under the condition of high gas content, its pressurization performance improvement cannot make up for the efficiency decline caused by gas accumulation.

[0016] Reference document 2 (CN120292117A) focuses on suppressing leakage flow at the blade tip, using trapezoidal grooves to disperse vortices on the impeller surface to reduce vibration and wear. However, it does not address the essential phase separation of the gas and liquid phases inside the impeller and lacks direct control over the formation of gas clusters and gas accumulation within the flow channel. Therefore, it cannot solve the problem of a sharp drop in head and efficiency caused by gas accumulation.

[0017] Reference document 3 (CN101603530B) achieves internal leakage unloading through the variable meshing clearance of the scroll disk, mainly solving the problems of sudden pressure increase and liquid hammer when the liquid content is high. However, it does not suppress the local accumulation of gas phase in the impeller channel (such as gas clouds on the blade suction surface or hub surface), and its unloading mechanism depends on the intermittent leakage of the compression chamber. It cannot actively control the momentum distribution of the gas and liquid phases, making it difficult to operate stably under wide gas-liquid ratio conditions.

[0018] In summary, existing technologies either focus on adjusting macroscopic flow channel parameters (such as blade placement angle and wrap angle) or are limited to single structural improvements (such as blade tip grooves and vortex disk profiles), without addressing the dynamic formation process of gas phase aggregation (such as initial micro-particle interception, mid-scale gas mass fragmentation, and full-channel dispersion). Therefore, there is an urgent need for a novel impeller composite structure capable of accurately intercepting initial micro-gas masses, actively fragmenting mid-scale gas masses, dynamically controlling gas-liquid momentum exchange, and adapting to a wide range of operating conditions, in order to overcome the technical bottleneck of flow instability caused by phase separation in multiphase mixed-transport pumps. Summary of the Invention

[0019] The purpose of this invention is to provide a multiphase flow gas phase aggregation suppression type impeller composite structure to solve the problems in the prior art that rely solely on macroscopic flow channel optimization or single structural improvement, which cannot effectively suppress phase separation throughout the entire gas phase aggregation process, making it difficult to operate stably under a wide range of operating conditions, and easily causing flow channel blockage and performance degradation.

[0020] To achieve the above objectives, the present invention provides the following technical solution: a multiphase flow gas phase aggregation suppression type mixed-transport pump impeller composite structure, comprising a hub, a plurality of blades uniformly distributed around the central axis of the hub, and a wheel cover connected to the outer edge of the blades, wherein: the inlet edge of the blade is located between the hub and the wheel cover, and the outlet edge extends to the outer edge of the wheel cover; the leading edge of the inlet edge of the blade is provided with a rounded chamfer with a radius of 2mm to 5mm, and the minimum gap between the inlet edge of the blade and the surface of the hub is 1.5% to 3.0% of the impeller inlet diameter.

[0021] Preferably, the inlet edge of each blade is inclined forward in the direction of impeller rotation, forming an inlet angle of attack α of 15° to 30°.

[0022] Preferably, the blade profile is asymmetrically twisted along the direction from the inlet section, middle section to the outlet section, wherein the blade placement angle β1 in the inlet section is 25-35°, and the blade thickness gradually increases from 3-5 mm at the inlet edge to 6-8 mm in the middle section.

[0023] Preferably, the length of the middle section is greater than the lengths of the inlet and outlet sections, and the blade placement angle β2 of the middle section decreases linearly from β1 to 15–20°. A shallow groove with a width of 1–2 mm and a depth of 0.5–1 mm is formed on the suction surface side of the blade in this section, along the flow channel direction. This shallow groove is used to disturb the bottom boundary layer, induce small-scale turbulence, and promote interfacial mixing.

[0024] Preferably, the length of the outlet section is shorter than that of the inlet section, the blade placement angle β3 of the outlet section is 5 to 10°, and the blade thickness gradually decreases to 4 to 6 mm to ensure a smooth transition of the fluid to the guide vane.

[0025] Preferably, two to four triangular prism-shaped dynamic vortex generators are spaced apart on the suction side of the blade's middle section. The dynamic vortex generators have a base length of 3-5 mm and a height of 2-3 mm, with their tops pointing downstream of the flow channel. The dynamic vortex generators can actively generate vortices of controllable intensity, directly impacting and dispersing any potential local air masses, thereby enhancing gas-liquid momentum exchange.

[0026] Preferably, the area adjacent to the hub and the blade inlet section is provided with a rough surface. The rough surface is formed by laser etching or shot peening. The rough surface is a uniformly distributed array of micro-pits with a diameter of 0.5-1 mm, a depth of 0.1-0.3 mm, and a center-to-center distance of 2-3 mm between adjacent pits. The rough surface can destroy the lubricating layer formed by the gas phase on the hub wall, increase the gas sliding resistance, and inhibit its accumulation along the wall.

[0027] Preferably, the leading edge of the blade inlet is provided with a gradient porous permeation layer, which is made of metal powder sintering or porous ceramic.

[0028] Preferably, the dynamic vortex generator integrates an intelligent control system, which includes miniature pressure sensors and optical bubble sensors arranged at key locations near the vortex generator on the blade surface and in the flow channel, for real-time acquisition of gas phase volume fraction, local pressure fluctuations and gas mass size distribution.

[0029] Compared with existing technologies, the present invention has the following beneficial effects: Through the synergistic effect of multiple levels of structures such as a gradient porous permeable layer, a variable cross-section dynamic vortex generator, asymmetric twisted blades, and micro-pitted rough surface, the present invention forms a near-wall-core full-domain separation system by cooperating with and complementing each other's advantages. This system intervenes in gas phase accumulation from different levels and angles, achieving uniform gas phase dispersion throughout the entire flow channel. Specific technical effects include the following:

[0030] 1. By intercepting small air masses at the inlet edge through a gradient porous permeable layer, guiding stable gas-liquid acceleration through the asymmetric twisted blade profile, precisely breaking up medium-sized air masses through a dynamic vortex generator with a variable cross-section in the middle section of the flow channel, and destroying gas phase wall adhesion through the rough surface of the hub micro-dimples, the entire process of gas phase suppression from initial formation to accumulation in the middle and later stages is achieved. This effectively solves the problem of local accumulation of gas phase in the impeller flow channel to form air masses / blockages, avoids flow channel blockage, and significantly improves the stable operation capability of the pump.

[0031] 2. The variable cross-section dynamic vortex generator adopts a composite structure of a trapezoidal front section and a triangular rear section, which can induce vortices of different intensities in segments according to the gas-liquid flow characteristics at different positions in the flow channel, and significantly improves the breaking efficiency of medium-sized air masses.

[0032] 3. The intelligent control system monitors the gas phase volume fraction, local pressure fluctuations, and gas mass size distribution in real time, and dynamically adjusts the vortex generator parameters and impeller speed. It can respond quickly and maintain stable operation under conditions where the gas-liquid ratio fluctuates from 10% to 50%, solving the problems of insufficient adaptability and passive control of existing technologies, and has a wider range of operating condition adaptability.

[0033] 4. The hydrophobic treatment of the gradient porous permeable layer reduces gas phase adhesion, and the dynamic vortex generator uniformly disperses the gas phase to avoid local high-speed flow of the liquid phase, so that the gas and liquid phases are evenly distributed, reducing the local flow velocity impact of the flow components and significantly reducing local erosion and wear. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0035] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention;

[0036] Figure 2 This is a schematic diagram of the structure of Embodiment 2 of the present invention;

[0037] Figure 3 This is a schematic diagram of the structure of Embodiment 3 of the present invention.

[0038] In the picture:

[0039] 1. Hub; 2. Blade; 3. Wheel cover; 4. Rough surface. Detailed Implementation

[0040] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0041] As attached Figure 1 As shown:

[0042] Example 1: This invention provides a multiphase flow gas-phase aggregation suppression type mixed-transport pump impeller composite structure, including a hub 1, several blades 2 evenly distributed around the central axis of the hub 1, and a cover 3 connected to the outer edge of the blades 2. The inlet edge of the blades 2 is located between the hub 1 and the cover 3, and the outlet edge extends to the outer edge of the cover 3, providing a wider discharge space for the fluid. When the gas-liquid two-phase medium gains energy within the impeller through the action of the blades, it can be discharged more smoothly from the impeller to subsequent flow channels (such as guide vanes). If the outlet edge does not extend to the outer edge of the cover, it may restrict fluid discharge, causing congestion at the impeller outlet, increasing flow resistance, and reducing pump efficiency. The leading edge of the inlet edge of the blades 2 has a rounded chamfer with a radius of 2mm to 5mm, and the minimum clearance between the inlet edge of the blades 2 and the surface of the hub 1 is 1.5% to 3.0% of the impeller inlet diameter.

[0043] Working principle: In Example 1, when the gas-liquid mixed medium flows through the impeller inlet, the inlet edge with a specific rounded chamfer can smoothly guide the medium, effectively reducing flow separation and inlet impact loss. At the same time, the precisely designed gap between the blade 2 and the hub 1 forms a controllable near-wall leakage flow. This leakage flow has a high tangential velocity under the action of centrifugal force. Its entrainment effect along the hub 1 wall towards the mainstream area can continuously sweep away small-scale gas nuclei that may accumulate on the surface of the hub 1. Thus, in the initial stage of flow, it disrupts the path of stable adhesion and aggregation of the gas phase on the hub 1 wall to form large gas clouds, laying a good foundation for further gas-liquid mixing in the subsequent flow channel.

[0044] As attached Figure 2 As shown:

[0045] Example 2: This invention provides a multiphase flow gas phase aggregation suppression type mixed-transport pump impeller composite structure, including a hub 1, a plurality of blades 2 evenly distributed around the central axis of the hub 1, and a wheel cover 3 connected to the outer edge of the blades 2, wherein: the inlet edge of the blades 2 is located between the hub 1 and the wheel cover 3, and the outlet edge extends to the outer edge of the wheel cover 3; the leading edge of the inlet edge of the blades 2 is provided with a rounded chamfer with a radius of 2mm to 5mm, and the minimum gap between the inlet edge of the blades 2 and the surface of the hub 1 is 1.5% to 3.0% of the impeller inlet diameter; the inlet edge of each blade 2 is inclined forward in the impeller rotation direction and forms an inlet angle α of 15° to 30°.

[0046] 1. In one embodiment of the present invention, the profile of the blade 2 is asymmetrically twisted along the direction from the inlet section, the middle section to the outlet section, wherein the blade 2 placement angle β1 in the inlet section is 25 to 35°, and the thickness of the blade 2 gradually increases from 3 to 5 mm at the inlet edge to 6 to 8 mm in the middle section.

[0047] 2. In one embodiment of the present invention, the length of the middle section is greater than the lengths of the inlet section and the outlet section, and the placement angle β2 of the blade 2 in the middle section linearly decreases from β1 to 15-20°. A shallow groove with a width of 1-2 mm and a depth of 0.5-1 mm is formed on the suction surface side of the blade 2 in this section, along the flow channel direction. This shallow groove is used to disturb the bottom boundary layer, induce small-scale turbulence, and promote interfacial mixing.

[0048] 3. In one embodiment of the present invention, the outlet section is shorter than the inlet section, the blade 2 of the outlet section is placed at an angle β3 of 5 to 10°, and the thickness of the blade 2 is gradually reduced to 4 to 6 mm to ensure that the fluid smoothly transitions to the guide vane.

[0049] Working Principle: Unlike Example 1, in Example 2, the inlet edge of the blade 2 with a specific forward tilt angle allows the medium to acquire a pre-swirling tangential velocity consistent with the impeller's rotation direction before entering the flow channel. This pre-swirling motion effectively reduces the relative slippage between the gas and liquid due to inertia differences, making it easier for the low-momentum gas phase to be entrained by the liquid phase and enter the flow channel, rather than directly separating and impacting the hub 1 at the inlet. After entering the flow channel, the blade curvature, combined with the pre-swirling velocity, guides the gas and liquid to accelerate stably, gradually increasing the blade thickness to suppress flow separation, maintaining initial gas-liquid mixing, and avoiding front-end aggregation. The shallow grooves on the suction surface in the middle section of the flow channel continuously disturb the low-speed boundary layer near the wall, generating a series of small-scale vortices. These vortices act like micro-stirring devices, initially cutting and mixing the gas phase migrating to the vicinity of the suction surface, preventing it from re-aggregating and growing, thus preparing for subsequent deep processing.

[0050] As attached Figure 3 As shown:

[0051] Example 3: This invention provides a multiphase flow gas phase aggregation suppression type mixed-transport pump impeller composite structure, including a hub 1, several blades 2 evenly distributed around the central axis of the hub 1, and a wheel cover 3 connected to the outer edge of the blades 2, wherein: the inlet edge of the blades 2 is located between the hub 1 and the wheel cover 3, and the outlet edge extends to the outer edge of the wheel cover 3; the leading edge of the inlet edge of the blades 2 is provided with a rounded chamfer with a radius of 2mm to 5mm, and the minimum gap between the inlet edge of the blades 2 and the surface of the hub 1 is 1.5% to 3.0% of the impeller inlet diameter; the profile of the blades 2 is asymmetrically twisted along the inlet section, middle section and outlet section, wherein the blade 2 placement angle β1 in the inlet section is 25 to 35°, and the thickness of the blades 2 gradually increases from 3 to 5mm at the inlet edge to 6 to 8mm in the middle section; two to four dynamic vortex generators (not shown in the figure) are spaced apart on the suction surface side of the middle section of the blades 2, the bottom edge of the dynamic vortex generator is 3 to 5mm long and 2 to 3mm high, and its installation direction is that the top point points downstream of the flow channel. The dynamic vortex generator can actively generate vortices with controllable intensity, directly impacting and breaking up any potential local air masses, thereby enhancing gas-liquid momentum exchange.

[0052] 1. In one embodiment of the present invention, a rough surface 4 is provided in the region adjacent to the inlet section of the hub 1 and the blade 2. The rough surface 4 is formed by laser etching or shot peening. The rough surface 4 is a uniformly distributed array of micro-pits with a diameter of 0.5-1 mm, a depth of 0.1-0.3 mm, and a center-to-center distance of 2-3 mm between adjacent pits. The rough surface 4 can destroy the lubrication layer formed by the gas phase on the wall of the hub 1, increase the gas sliding resistance, and inhibit its accumulation along the wall.

[0053] Working Principle: Unlike Embodiment 2, Embodiment 3 incorporates dynamic vortex generators installed on the suction surface in the middle section of the flow channel. When gaseous clumps, guided and initially broken up by the preceding stages, flow through this region, these dynamic vortex generators forcibly cut the flow field, generating directional vortices of controllable intensity and appropriate size in their wake. These vortices possess higher local kinetic energy, enabling them to penetrate deep into the flow field and thoroughly tear apart and break up medium-sized gas clumps that were not completely dispersed in the previous stage or attempted to re-aggregate, transforming them into smaller and more uniformly dispersed bubbles. This significantly enhances the momentum and mass exchange efficiency between the gas and liquid phases. Simultaneously, the micro-dimpled rough surface 4 at the inlet section of hub 1, by increasing wall roughness, disrupts the conditions for the gas phase to adhere and form a low-friction air cushion layer. The resulting micro-separation vortices and additional frictional resistance effectively inhibit the tendency of gas to creep and accumulate along the wall of hub 1, forming an effective combination with the main separation suppression measures in the flow channel, jointly ensuring a full-space separation suppression effect from the core area of ​​the flow channel to the near-wall area.

[0054] 2. In one embodiment of the present invention, in order to further precisely break up the medium-sized air masses (0.5-2 mm in diameter) that are prone to re-aggregation in the middle and rear sections of the flow channel and enhance the gas-liquid momentum exchange throughout the flow channel, the dynamic vortex generator adopts a variable cross-section composite structure design. It is a variable cross-section dynamic vortex generator, which is set as a trapezoidal front section and a triangular rear section from front to back along the flow direction of the middle section of blade 2. The trapezoidal front section (the middle section area near the inlet edge of blade 2, 1 / 3) is an isosceles trapezoidal cross section, which is used to induce the generation of low-intensity vortices to pre-entrain small gas phase micro-particles; the rear section (the middle section area near the rear 2 / 3 of blade 2) is an equilateral triangular cross section, which is used to induce the generation of high-intensity vortices to completely break up the medium-sized air masses. The variable cross sections are smoothly connected by arc surfaces, and the tops of all cross sections point to the downstream of the flow channel. By segmentally controlling the vortex intensity and size, the gas-liquid flow characteristics at different positions in the flow channel are matched. It works in conjunction with the rough surface of the hub inlet section and the basic triangular prism vortex generator to achieve uniform dispersion and suppression of agglomeration of the gas phase throughout the flow channel.

[0055] Example 4: This invention provides a multiphase flow gas phase aggregation suppression type mixed-transport pump impeller composite structure, including a hub 1, several blades 2 evenly distributed around the central axis of the hub 1, and a wheel cover 3 connected to the outer edge of the blades 2, wherein: the leading edge of the inlet edge of the blades 2 (the 1 / 8 chord length region near the impeller inlet) is provided with a gradient porous permeation layer (not shown in the figure), the gradient porous permeation layer is a gradient porous layer made of metal powder sintering or porous ceramic (porosity is high at the leading edge (40%~60%) and decreases towards the trailing edge (20%~30%)), and the pore size is 50~200μm (allowing the liquid phase to pass freely, but hindering the direct penetration of small gas phase agglomerates (diameter <0.3mm).

[0056] 1. In one embodiment of the present invention, in order to further enhance the interception and dispersion efficiency of the initial small gas clusters at the impeller inlet edge and suppress the premature accumulation of gas phase at the leading edge of blade 2, the gradient porous permeable layer adopts a composite structure design of gradient porosity and variable thickness. Its leading edge (the 1 / 8 chord length region near the impeller inlet) has a porosity set at 50%–60% (highest), decreasing to 35%–45% along the blade 2 chord towards the middle and rear (1 / 8–1 / 4 chord length region), and further decreasing to 35%–45% along the trailing edge (1 / 8–1 / 4 chord length region). The thickness of the porous layer is further reduced to 20%–30% (minimum) in the 4–1 / 2 chord length region; at the same time, the thickness of the porous layer gradually decreases from 1.2–1.5 mm at the inlet edge (near the impeller inlet side) to 0.6–0.8 mm in the middle and rear part (smoothly transitioning with the surface of blade 2); the porous layer material is a sintered metal powder (pore size 50–100 μm) or porous ceramic (pore size 100–200 μm), and the surface is hydrophobically treated (contact angle >120°) to reduce gas phase adhesion.

[0057] Working principle: When the gas-liquid mixture enters the impeller inlet, the initial micro-gas clusters (diameter <0.3mm) are mainly concentrated in the 1 / 8 chord length region near the impeller inlet (where the flow velocity is highest but the gas phase is most prone to aggregation). This embodiment uses a gradient porosity design, with higher porosity at the front and lower at the rear. The highest porosity (50%–60%) and maximum thickness are set in the leading edge region (1 / 8 chord length) where micro-clusters are most likely to aggregate at the inlet edge. Utilizing the capillary action and micropore resistance of the high porosity, newly formed microbubbles or those carried by the liquid phase are efficiently intercepted and retained. Subsequently, the porosity decreases (35%–45%) and the thickness decreases (0.6–0.8mm) towards the middle and rear of the chord, ensuring normal liquid phase passage while secondary dispersion of residual micro-clusters that have passed through the leading edge interception. Surface hydrophobic treatment further reduces the probability of gas phase adhesion, preventing micro-clusters from remaining and nucleating on the porous layer surface. Through this composite structural design, the gradient porous permeable layer can not only accurately intercept the smallest initial micro-clusters at the inlet edge, but also achieve a functional transition from high-efficiency interception to gradual dispersion through dynamic adjustment of porosity and thickness. It works in synergy with the dynamic vortex generator in the middle section of blade 2 and the rough surface of the hub to form a full-process gas phase suppression system of "inlet interception - middle section crushing - full flow channel dispersion", which significantly reduces the probability of gas phase accumulation at the impeller inlet edge and improves the pump's stable operation under high pressure difference and high gas-liquid ratio conditions.

[0058] It is worth noting that the interception in Example 4 is not intended to block the gas phase inside the pump and prevent it from being transported normally to the outlet, but rather to be a proactive and strategic gas phase control method, primarily targeting initial micro-gas clusters that may lead to adverse consequences. Specifically, it intercepts the initial micro-gas clusters that are just beginning to form at the impeller inlet edge. If these micro-gas clusters are not effectively treated at the inlet edge, they can easily accumulate and form large gas clusters / blocks in the subsequent impeller flow channel. Utilizing a special gradient porosity and variable thickness composite structure design, it efficiently intercepts and retains newly formed microbubbles or those carried by the liquid phase, while allowing the liquid phase to pass freely. The purpose of this is to initially control these micro-gas clusters at the inlet edge, preventing them from directly entering the impeller flow channel and rapidly merging with other gas phases to form large gas clusters, rather than preventing the gas phase from entering the pump. Taking the gradient porous permeable layer as an example, its porosity is high at the leading edge and decreases towards the trailing edge, and its thickness also gradually decreases from the inlet edge to the middle and rear parts, transitioning smoothly with the surface of blade 2. This design ensures efficient interception of tiny gas clusters in the leading edge region where they are most likely to accumulate at the inlet, while allowing both gas and liquid phases to pass smoothly through the subsequent regions. Furthermore, the hydrophobic treatment of the porous layer material surface reduces gas adhesion, further lowering the risk of clogging.

[0059] Example 5:

[0060] Example 5 further extends Example 3 by integrating an intelligent control system into the dynamic vortex generator. This system includes miniature pressure sensors and optical bubble sensors positioned near key locations on the surface of blade 2 and within the flow channel, which collect real-time data on gas volume fraction, local pressure fluctuations, and gas cloud size distribution. The sensor data is fed back in real-time to the external intelligent control unit via a signal transmission module built into the impeller shaft. The intelligent control unit incorporates an adaptive algorithm, the core of which is a multi-parameter fusion control strategy based on fuzzy logic and PID control, specifically implementing the following dynamic adjustment functions:

[0061] Data preprocessing and feature extraction: The intelligent control unit first performs a fast Fourier transform on the pressure fluctuation signal collected in real time by the sensor to extract the characteristic frequency components related to gas phase aggregation (such as low-frequency fluctuations of 0~10Hz corresponding to large-scale gas mass disturbances, and high-frequency fluctuations of 10~30Hz corresponding to microbubble flow); at the same time, combined with the data from the optical bubble sensor, the time series change rate of gas phase volume fraction and the standard deviation (σ) of gas mass size distribution are calculated to comprehensively characterize the dynamic trend of gas phase aggregation.

[0062] Threshold Judgment and Decision-Making: Three-level response thresholds are set: When the gas phase volume fraction C < 2% and the pressure fluctuation ΔP < 1.0 kPa, it is judged as a stable operating condition, and the algorithm keeps the initial design parameters of the vortex generator (standard angle of attack α0 and installation spacing d0) unchanged; when 2% ≤ C < 5% and 1.0 kPa ≤ ΔP < 1.5 kPa, it is judged as a mild gas phase accumulation operating condition, and the algorithm fine-tunes the impeller speed through the pump's variable frequency control system (adjustment range ±5%, corresponding to a 10% to 15% change in the vortex intensity induced by the vortex generator), enhancing the influence of the liquid phase mainstream on the gas phase. The entrainment effect; when C≥5% or ΔP≥1.5kPa, it is judged as a medium-to-heavy gas phase accumulation condition. The algorithm adjusts the effective angle of attack (α=α0±10°~15°, adjustment accuracy ±1°) and installation spacing (d=d0±0.1~0.2mm, adjustment accuracy ±0.05mm) of the variable cross-section dynamic vortex generator in real time. The vortex generator fixing bracket is driven by a micro servo motor to change the vortex direction and range of action, thereby increasing the vortex intensity by 20%~40%, accurately entraining and breaking up the accumulated medium-sized gas clouds (0.5~2mm in diameter).

[0063] Dynamic feedback and parameter optimization: The algorithm updates the vortex generator control parameters every 0.5 seconds based on real-time monitoring data, and learns from historical data (stores the operating data of the last 10 minutes) to predict the evolution trend of gas phase accumulation and adjust the control strategy in advance (such as increasing the vortex intensity by 5% to 10% in advance when it is predicted that the gas phase volume fraction will continue to rise), forming a closed-loop control of perception-decision-execution-optimization.

[0064] Example 6:

[0065] This invention provides a multiphase flow gas phase aggregation suppression type mixed-transport pump impeller composite structure. Based on any one of the embodiments one to five, the impeller also features an innovative tandem blade design. This tandem blade design consists of two blades, one in front and one behind, with a specific spacing maintained between them. This spacing is optimized to ensure that a high-speed jet can be generated between them.

[0066] The working principle of tandem blade cascades: By utilizing the high-speed jet generated between the front and rear blade cascades, the momentum and energy exchange between phases are enhanced, thereby reconstructing gas-liquid mixing to reduce the degree of gas-liquid separation and inhibit gas phase agglomeration.

[0067] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A multiphase flow gas phase aggregation inhibiting mixed flow pump impeller composite structure, comprising a hub (1), a plurality of blades (2) uniformly distributed around the central axis of the hub (1), and a cover (3) connected to the outer edge of the blade (2), characterized in that: The inlet edge of the blade (2) is located between the hub (1) and the cover (3), and the outlet edge extends to the outer edge of the cover (3); the front edge of the inlet edge of the blade (2) is provided with a circular arc chamfer with a radius of 2mm-5mm, and the minimum gap between the inlet edge of the blade (2) and the surface of the hub (1) is 1.5%-3.0% of the inlet diameter of the impeller, when the gas-liquid mixed medium flows through the impeller inlet, a controllable near-wall leakage flow is formed between the blade (2) and the hub (1).

2. A multiphase flow gas phase aggregation inhibiting mixed flow pump impeller composite structure according to claim 1, characterized in that: The inlet edge of each blade (2) is inclined forward in the direction of rotation of the impeller, and forms an inlet angle α of 15°-30°.

3. A multiphase flow gas phase aggregation inhibiting mixed flow pump impeller composite structure according to claim 1, characterized in that: The profile of the blade (2) is asymmetrically twisted along the direction from the inlet section to the outlet section, wherein the blade angle β1 of the blade (2) at the inlet section is 25-35°, and the thickness of the blade (2) gradually increases from 3-5mm at the inlet edge to 6-8mm at the middle section.

4. A multiphase flow gas phase aggregation inhibiting mixed flow pump impeller composite structure according to claim 3, characterized in that: The length of the middle section of the blade (2) is greater than the lengths of the inlet section and the outlet section, and the blade angle β2 of the blade (2) at the middle section linearly decreases from β1 to 15-20°.

5. A multiphase flow gas phase aggregation inhibiting mixed flow pump impeller composite structure according to claim 3, characterized in that: The outlet section is smaller than the inlet section, the blade angle β3 of the blade (2) at the outlet section is 5-10°, and the thickness of the blade (2) gradually decreases to 4-6mm.

6. A multiphase flow gas phase aggregation inhibiting mixed flow pump impeller composite structure according to claim 3, characterized in that: A plurality of dynamic vortex generators are arranged on the suction surface side of the middle section of the blade (2).

7. A multiphase flow gas phase aggregation inhibiting mixed flow pump impeller composite structure according to claim 1, characterized in that: The hub (1) is provided with a rough surface (4) adjacent to the inlet section of the blade (2).

8. A multiphase flow gas phase aggregation inhibiting mixed flow pump impeller composite structure according to claim 7, characterized in that: The rough surface (4) is formed by laser etching or shot blasting process, and the rough surface (4) is an array of uniformly distributed micro-pits with a diameter of 0.5-1mm, a depth of 0.1-0.3mm, and a center distance of 2-3mm between adjacent pits.

9. A multiphase flow gas phase aggregation inhibiting mixed flow pump impeller composite structure according to claim 1, characterized in that: The front edge of the inlet edge of the blade (2) is provided with a gradient porous permeation layer, and the gradient porous permeation layer is made of a gradient porous layer made of metal powder sintering or porous ceramic.

10. A multiphase flow gas phase aggregation suppressing mixed flow pump impeller composite structure according to claim 6, characterized in that: The dynamic vortex generator is integrated with an intelligent control system, and the intelligent control system includes micro pressure sensors and optical bubble sensors arranged on the surface of the blade (2) and at key positions near the vortex generator in the flow channel, for real-time acquisition of gas volume fraction, local pressure fluctuation and gas group size distribution.

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