Oil-gas multiphase pump blade tip leakage flow suppression structure, design method and oil-gas multiphase pump

Abstract

The invention relates to the technical field of axial flow pumps, and discloses an oil-gas multiphase pump blade tip leakage flow restraining structure, a design method and an oil-gas multiphase pump, the leakage flow restraining structure comprises an impeller blade, a groove is formed in the top of the impeller blade, and the projection of the groove in a plane perpendicular to the skeleton line direction of the impeller blade is trapezoidal. According to the structural design of the trapezoidal grooves at the tops of the blades of the impeller, vortex and turbulent flow on the surface of the impeller are effectively scattered through fine regulation and control of fluid, impact and abrasion of the fluid to the impeller are reduced, and therefore the vibration level of the multiphase pump is remarkably reduced, and the service life of the impeller is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of axial flow pumps, and more specifically to a structure for suppressing tip leakage flow of an oil-gas mixed transportation pump, a design method, and an oil-gas mixed transportation pump. Background Art

[0002] China has huge potential in offshore oil and gas resources. According to the fourth national oil and gas resources survey, offshore oil reserves account for about 34% of the total national reserves, and natural gas reserves account for about 52% of the country's total. Therefore, the exploration, development, and exploitation of offshore oil and gas resources have important strategic significance. As the core equipment of oil-gas mixed transportation technology, the oil-gas mixed transportation pump undertakes the key task of efficiently transporting offshore oil and gas resources to onshore platforms. This pump has the advantages of a wide operating range, a compact structure, and strong abrasion resistance, and is widely used in the transportation systems of offshore oil and gas fields.

[0003] During the operation of the oil-gas mixed transportation pump, there must be a certain "tip clearance" between the impeller and the pump body wall. The impeller rotates at a high speed around the main shaft, and part of the fluid medium will leak from the pressure side of the blade to the suction side through the tip clearance, forming a high-speed tip leakage flow, which is manifested as a wall jet. The tip leakage flow interacts with the mainstream in the flow channel, generating mixing and entrainment, and finally forming a tip leakage vortex. The tip leakage vortex is the main factor causing the instability of the internal flow of the mixed transportation pump. It not only increases the hydraulic loss but also reduces the energy conversion efficiency of the pump. In addition, the formation of the tip leakage vortex may cause problems such as cavitation, vibration, and noise, further affecting the stability and long-term operating performance of the pump. Therefore, conducting research on the vibration reduction and noise reduction technology of the mixed transportation pump, especially optimizing the impeller design, has significant application value and urgent practical needs.

[0004] The utility model patent with the publication number CN216867077U discloses a passive control structure for gap eddy current of an axial flow pump, in which a C-shaped groove is opened at the tip of the runner blade. Under the pressure difference between the pressure side and the suction side of the runner blade, a jet flow is formed in the C-shaped groove to inhibit the development of the gap eddy current. Although the C-shaped groove design can inhibit part of the gap eddy current, its structure is relatively simple, lacks flexibility, fails to fully meet the special requirements of the oil-gas mixed transportation pump in complex fluids, and has limited control effects on eddy current and turbulence.

[0005] Another example is the invention patent with the publication number CN118328014A, which discloses a groove jet structure and a flow control method. Grooves are opened at the top of the blade, and the jet angle is controlled by a cubic function type groove to inhibit tip leakage. However, this structure design is only applicable to single-phase liquids with stable flow, fails to fully optimize the mixing effect of oil-gas two-phase flow, and has limited effects in suppressing eddy current and turbulence, and fails to effectively improve the overall efficiency and stability of the pump. Summary of the Invention

[0006] To solve the problems and deficiencies existing in the above-mentioned prior art, the present invention proposes a structure for suppressing tip leakage flow of an oil-gas mixed transmission pump, a design method, and an oil-gas mixed transmission pump. The trapezoidal groove structure at the tip of the blade of the present invention can suppress the development of tip leakage vortices, and is particularly suitable for oil-gas two-phase flow mixed transmission pumps, thereby reducing the vibration and noise of the oil-gas mixed transmission pump.

[0007] To achieve the above-mentioned invention purpose, the technical solution of the present invention is specifically as follows: The present invention discloses a structure for suppressing tip leakage flow of an oil-gas mixed transmission pump. The tip leakage flow suppression structure includes a trapezoidal groove provided at the top of the impeller blade. The trapezoidal groove structure forms a series of micro-channels at the top edge of the impeller blade. The function of these grooves is to effectively improve the fluid flow state, reduce vortex and backflow phenomena, thereby reducing the energy loss in the mixed transmission pump. At the same time, the grooved tip can promote the mixing of oil and gas, improve the mixing uniformity, and make the flow of the oil-gas mixture in the pump more stable. In addition, this design of the tip groove structure can also reduce the noise and vibration during the operation of the mixed transmission pump, thereby extending the service life of the impeller and improving the overall working efficiency and reliability of the oil-gas mixed transmission pump.

[0008] Preferably, the trapezoidal groove is provided at the top of the impeller blade along the radial direction towards the outside, and the projection of the groove in a plane perpendicular to the blade camber line direction of the impeller blade is trapezoidal.

[0009] Preferably, the top of the impeller blade has a leading edge and a trailing edge in the circumferential direction, and a plurality of the grooves are arranged along the direction from the leading edge to the trailing edge.

[0010] Preferably, the top of the impeller blade has a leading edge and a trailing edge, and the groove extends along the circumferential direction of the impeller blade, starting from the leading edge and ending at the trailing edge.

[0011] Preferably, the ratio of the top width of the groove to the thickness of the impeller blade is 0.2 - 0.8.

[0012] Preferably, the ratio of the bottom width of the groove to the thickness of the impeller blade is 0.2 - 0.9.

[0013] Preferably, the ratio of the depth of the groove to the thickness of the impeller blade is 0.2 - 1.2.

[0014] Preferably, the range of the angle α between the left inclined side of the groove and the straight line where the top line segment of the impeller blade is located is 0° - 135°.

[0015] Preferably, the range of the angle β between the right inclined side of the groove and the straight line where the top line segment of the impeller blade is located is 0° - 135°.

[0016] Based on the same inventive concept, the present invention also discloses a design method for a structure for suppressing tip leakage flow of an oil-gas mixed transportation pump. The method is used to design the above-mentioned structure for suppressing tip leakage flow, and the design process is as follows: Step A. Set a plane that is perpendicular to the direction of the blade camber line of the impeller; on this plane, set an X-axis and a Y-axis respectively. The X-axis coincides with the straight line where the top segment of the impeller blade is located, and the Y-axis passes through the blade camber line and is perpendicular to the X-axis at point O. Step B. Design a groove at the top of the impeller blade. The projection of the groove in the set plane is trapezoidal and symmetric about the Y-axis. Step C. Determine the groove parameters according to the flow rate, rotational speed and head of the oil-gas mixed transportation pump, including the top width b of the groove, the bottom width c of the groove, the depth h of the groove, the angle α between the left inclined side of the groove and the positive direction of the X-axis, and the angle β between the right inclined side of the groove and the negative direction of the X-axis. Step D. Apply the groove parameters determined in Step C to the designed impeller blade, and finally complete the design of the impeller blade of the oil-gas mixed transportation pump.

[0017] Furthermore, the present invention also provides an oil-gas mixed transportation pump, which includes a housing and an impeller and a diffuser arranged in the housing. The impeller is composed of an impeller hub and the above-mentioned impeller blade.

[0018] Advantages of the present invention: (1) The trapezoidal groove structure design at the tip of the blade of the present invention effectively disperses the vortices and turbulences on the surface of the impeller through fine regulation of the fluid, reduces the impact and wear of the fluid on the impeller, thereby significantly reducing the vibration level of the pump and extending the service life of the impeller.

[0019] (2) The trapezoidal groove structure design at the tip of the blade of the present invention optimizes the flow path of the fluid inside the mixed transportation pump, reduces the flow loss, improves the efficiency of the pump, and enables the pump to be more energy-saving and efficient when transporting the oil-gas mixture.

[0020] (3) The trapezoidal groove at the tip of the blade of the present invention can disperse the fluid impact, reduce the pressure pulsation and turbulent noise, helps to improve the sound wave propagation path, effectively absorbs and scatters the sound energy, and reduces the radiation noise of the pump.

[0021] (4) The parameterized trapezoidal groove structure at the tip of the blade of the present invention can precisely control the trapezoidal tip shape by independently adjusting the groove width (b / c), depth (h) and inclined side angle (α / β) to achieve fine regulation of the gas-liquid two-phase flow.

[0022] (5) The trapezoidal groove structure design at the blade tip of the present invention can also promote the coalescence and escape of bubbles, effectively preventing the occurrence of cavitation phenomenon and ensuring the stable operation of the pump under complex working conditions.

[0023] (6) The trapezoidal groove structure at the blade tip of the present invention can also store a certain amount of lubricating medium, reduce the direct contact between the impeller and the pump casing, enhance the wear resistance of the impeller, and further extend the maintenance cycle and overall life of the pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The foregoing and following specific descriptions of the present invention become clearer when read in conjunction with the following drawings, in which: Figure 1 is an assembly sectional view of the oil-gas mixed transportation pump of the present invention; Figure 2 is a three-dimensional structure schematic diagram of the oil-gas mixed transportation pump of the present invention; Figure 3 is a three-dimensional structure schematic diagram of the impeller of the oil-gas mixed transportation pump of the present invention; Figure 4 is a two-dimensional plane schematic diagram of the top of the impeller blade of the oil-gas mixed transportation pump of the present invention.

[0025] In the figure: 1. Impeller; 2. Guide vane; 3. Outer casing; 4. Impeller hub; 5. Impeller blade; 6. Groove. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions for achieving the purpose of the present invention will be further described below through several specific embodiments. It should be noted that the technical solutions claimed by the present invention include but are not limited to the following embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the protection scope of the present invention.

[0027] The oil-gas mixed transportation pump is particularly suitable for transporting liquid mixtures containing a high proportion of gas, and its design incorporates the technical characteristics of a screw pump and an axial flow pump. As Figure 1 and Figure 2As shown, the oil-gas mixed transportation pump includes the following main components: impeller 1, guide vane 2, and housing 3. The oil-gas mixed medium enters from the left inlet of the mixed transportation pump, flows through the impeller flow channel and the guide vane flow channel in sequence, and is finally transported to a predetermined container. The impeller 1 is the core component of the mixed transportation pump. It generates centrifugal force through rotational motion, pushing the fluid to move axially to achieve effective transportation of the fluid. The design of the impeller optimizes the mixing of gas and liquid, reduces the occurrence of cavitation, ensures the stability and operating efficiency of the mixed transportation pump when dealing with complex media rich in gas, and improves the cavitation resistance of the pump. The function of the guide vane 2 is to guide and rectify the high-speed fluid output by the impeller to ensure the smooth flow of the oil-gas mixed medium. However, as a rotating component, there is a gap between the impeller and the stationary guide vane and housing. The existence of this gap will cause the fluid to leak from the top of the impeller to the inlet, thereby reducing the efficiency and head of the pump, decreasing the effective flow rate and increasing internal losses, and ultimately affecting the overall performance of the mixed transportation pump. Moreover, the two-phase flow (such as oil-gas and water-gas) in the mixed transportation pump is accompanied by gas-liquid stratification, interfacial slip, and flow pattern changes, which are more likely to trigger strong vortices and unsteady disturbances, resulting in unstable flow and increased energy losses.

[0028] Based on this, an embodiment of the present invention provides an oil-gas mixed transportation pump impeller tip leakage flow suppression structure, design method, and oil-gas mixed transportation pump. By designing a trapezoidal groove structure at the impeller tip of the present invention, the development of the tip leakage vortex can be significantly suppressed, especially suitable for oil-gas two-phase flow mixed transportation pumps, thereby reducing the vibration and noise of the oil-gas mixed transportation pump.

[0029] The following will make a more detailed explanation and description of the solution of the present invention in combination with specific implementation manners.

[0030] Embodiment 1 This embodiment discloses an oil-gas mixed transportation pump impeller tip leakage flow suppression structure. First, refer to the attached drawings of the specification Figure 3 As shown, Figure 3It is a three-dimensional structural schematic diagram of an impeller of a representative oil-gas mixed transportation pump. The impeller 1 of the mixed transportation pump includes the following components: an impeller hub 4 and impeller blades 5 arranged on the impeller hub 4. The number of blades is four. This impeller structure is a key component of an axial-flow mixed transportation pump, and its function and role are extremely important. Specifically, the main function of the impeller 1 is to convert the mechanical energy of the power source into the kinetic energy of the fluid, which is the basic principle of the operation of the mixed transportation pump. Driven by the motor, the pump shaft drives the impeller 1 to rotate at a high speed, and the fluid obtains energy under the action of the impeller blades 5, thereby achieving an increase in flow velocity and pressure. The design of the impeller 1 has a direct impact on the performance of the mixed transportation pump, such as flow rate, head, efficiency, and gas-liquid mixed transportation capacity, etc. Parameters such as the blade shape, number, angle, and inlet and outlet diameters of the impeller 1 are carefully designed and optimized to adapt to diverse working conditions and medium characteristics. In the application of the mixed transportation pump, the impeller 1 promotes the mixing and uniform distribution of gas-liquid two-phase media. The special design of its impeller blades 5 helps to reduce cavitation and the formation of bubbles, thereby enhancing the stability and reliability of the pump. In addition, the wear resistance and corrosion resistance of the impeller 1 are also important aspects considered in the design process, aiming to ensure the long-term stable operation of the mixed transportation pump in a harsh environment.

[0031] Figure 4 It shows a two-dimensional plane schematic diagram of the top of the impeller blade of the oil-gas mixed transportation pump of the present invention. This structure is a tip leakage flow suppression structure of the oil-gas mixed transportation pump of the present invention. Specifically, the tip leakage flow suppression structure is composed of the impeller blade 5 and a groove 6 arranged at the outer edge of the top of the impeller blade 5, and the groove is arranged at the top of the impeller blade and extends radially outward; further, the projection of the groove 6 in a plane perpendicular to the blade camber line direction of the impeller blade is trapezoidal. During the operation of the mixed transportation pump, the impeller 1 rotates to do work on the oil-gas two-phase fluid, and the fluid passes through the tip region from the suction surface of the impeller blade 5 (such as Figure 4 the right side shown in Figure 4 ), and flows to the pressure surface of the impeller blade 5 (such as the left side shown in ), and tip clearance flow is formed during this process. The existence of this tip clearance flow will lead to a decrease in the efficiency of the mixed transportation pump and a head loss, and cause distortion of the flow field and generate additional vibration and noise. The combined action of these adverse factors will not only weaken the conveying performance of the pump, but may also exacerbate the wear between the impeller and the pump casing, thereby affecting the stable operation and long-term use reliability of the pump.

[0032] According to an embodiment of the present invention, the impeller blades 5 of the oil-gas mixed transportation pump adopt a trapezoidal groove tip design. In this design, the trapezoidal grooves on the outer edge of the blade tip form a sunken cavity. This groove can guide the fluid to enter and form a cavity vortex, and this vortex effectively interferes with the conventional formation process of the tip leakage vortex. This design helps to reduce the separation of the fluid in the tip region and the generation of vortices, thereby reducing the turbulence intensity. By reducing the flow resistance at the blade tip, the trapezoidal groove tip in the embodiment of the present invention helps to improve the overall efficiency of the mixed transportation pump.

[0033] As a preferred embodiment, as Figure 4 shown, with reference to the thickness of the impeller blade, the ratio of the top width b of the trapezoidal groove to the thickness δ of the impeller blade is 0.2 - 0.8; the ratio of the bottom width c of the trapezoidal groove to the thickness δ of the impeller blade is 0.2 - 0.9; the ratio of the depth h of the trapezoidal groove to the thickness δ of the impeller blade is 0.2 - 1.2; the range of the angle α between the left inclined side of the groove and the straight line where the top line segment of the impeller blade is located is 0° - 135°; the range of the angle β between the right inclined side of the groove and the straight line where the top line segment of the impeller blade is located is 0° - 135°.

[0034] Embodiment 2 Based on Embodiment 1, the outer edge of the top of the impeller blade 5 has a leading edge and a trailing edge in the circumferential direction, and a plurality of the grooves 6 are arranged along the direction from the leading edge to the trailing edge.

[0035] It can be understood that in order to ensure the effect of the tip groove structure on improving the fluid flow state in the mixed transportation pump and reducing the phenomena of vortex and backflow, the distance between adjacent grooves should not be too large.

[0036] Embodiment 3 Based on Embodiment 1, the top of the impeller blade 5 has a leading edge and a trailing edge in the circumferential direction, and the groove 6 extends along the circumferential direction of the impeller blade 5, starting from the leading edge and ending at the trailing edge.

[0037] It can be understood that in order to ensure the effect of the tip groove structure on improving the fluid flow state in the mixed transportation pump and for convenient processing, the groove structure at the tip starts from the leading edge of the tip to the trailing edge, that is, it is arranged along the entire circumferential length of the outer edge of the tip, but does not penetrate the blade.

[0038] Embodiment 4 This embodiment discloses a design method for the tip leakage flow suppression structure of an oil-gas mixed transportation pump. The method is used to design the above-mentioned tip leakage flow suppression structure, and the structure design is carried out through three-dimensional modeling by digital software.

[0039] First, adopt the design method of three-dimensional stream surface to complete the basic shape design of the impeller of the oil-gas mixed transportation pump. The impeller 1 consists of an impeller hub 4 and impeller blades 5. The hub has the shape of a frustum of a cone, and a shaft hole is reserved at the axis. The blades are three-dimensionally twisted to improve the efficiency of transporting oil-gas two-phase flow. Based on the basic shape of the impeller designed above, then design the impeller blades according to the following steps, specifically as follows: Step A. Set a plane, which is a plane perpendicular to the direction of the impeller blade's camber line. On the set plane, set an X-axis and a Y-axis respectively. The X-axis coincides with the straight line where the top segment of the blade is located, and the Y-axis passes through the camber line of the blade and is perpendicular to the X-axis at point O. It is stipulated that the left side of the X-axis is the positive direction, and the right side is the negative direction; the upper side of the Y-axis is positive, and the lower side is negative.

[0040] Step B. Open a trapezoidal groove at the top of the impeller blade 5, and project the impeller blade 5 with the trapezoidal groove at the top onto the plane, and the projection is symmetric about the Y-axis.

[0041] Step C. Determine the groove parameters according to the flow rate, rotational speed and head of the oil-gas mixed transportation pump, including the top width b of the groove, the bottom width c of the groove, the depth h of the groove, the angle α between the left hypotenuse of the groove and the positive direction of the X-axis, and the angle β between the right hypotenuse of the groove and the negative direction of the X-axis.

[0042] In some embodiments, the trapezoidal groove is provided on the outer side along the radial direction of the blade tip, and the projection of the groove in the set plane is trapezoidal.

[0043] In some embodiments, on the X-axis, the thickness dimension of the impeller blade is δ.

[0044] In some embodiments, on the X-axis, the top of the trapezoidal groove coincides with the top of the blade, and the top of the groove is symmetric about the Y-axis. Define the width dimension of the top of the groove as b.

[0045] In some embodiments, on the plane, the bottom of the trapezoidal groove is parallel to the top of the trapezoidal groove. Define the width dimension of the bottom of the groove as c.

[0046] In some embodiments, on the plane, define the projection distance in the Y-axis direction between the top of the trapezoidal groove and the bottom of the trapezoidal groove as the height of the trapezoidal groove, and the height dimension of the groove is h.

[0047] In some embodiments, on the plane, the left hypotenuse connecting the top of the groove and the left bottom of the groove is the left hypotenuse of the trapezoidal groove. Define the angle between the left hypotenuse of the groove and the positive direction of the X-axis as α.

[0048] In some embodiments, on the plane, the right hypotenuse of the trapezoidal groove connecting the top of the groove and the right side of the bottom of the groove is defined, and the angle between the right hypotenuse of the groove and the negative X-axis is defined as β.

[0049] Step D. Apply the groove parameters determined in step C to the designed impeller blades, and finally complete the design of the impeller blades of the oil-gas mixed transportation pump.

[0050] As Figure 4 shown, with the blade thickness δ as a reference, the ratio of the top width b of the trapezoidal groove to the blade thickness δ is 0.2 - 0.8, that is, the value range of the top width b of the trapezoidal groove is 0.2 - 0.9δ. When the top width of the groove is relatively large, the fluid passage at the groove entrance increases, which helps to reduce the local turbulence and separation phenomenon of the fluid in the tip region, thus significantly reducing the occurrence probability of the tip separation vortex. By expanding the groove entrance, the flow of the fluid becomes smoother, reducing the formation of eddies caused by the change in flow velocity, and at the same time increasing the flow rate of the oil-gas two-phase flow in the groove, which helps to improve the flow state stability in the top region of the blade.

[0051] As Figure 4 shown, similarly with the blade thickness δ as a reference, the ratio of the bottom width c of the trapezoidal groove to the blade thickness δ is 0.2 - 0.9, that is, the value range of the bottom width c of the trapezoidal groove is 0.2 - 0.9δ. If the value of the bottom width of the groove is relatively large, the overall volume of the groove is larger, which can accommodate more fluid, and the formed groove vortex helps to promote the mixing of oil and gas, improve the mixing efficiency, ensure the uniformity of the output fluid, and enhance the stability of the fluid.

[0052] As Figure 4 shown, with the blade thickness δ as a reference, the ratio of the depth h of the trapezoidal groove to the blade thickness δ is 0.2 - 1.2, that is, the value range of the groove depth h is 0.2 - 1.2δ. If the value of the groove depth is relatively large, the oil-gas two-phase flow has a larger longitudinal space after entering the groove, which helps to reduce the flow velocity of the tip leakage flow, reduce the high-speed impact of the leakage flow, and effectively reduce the shear force and turbulence intensity of the flow. The reduction of the flow velocity helps to reduce the kinetic energy of the tip leakage flow, thereby reducing the formation of the tip separation vortex, optimizing the fluid stability, and enhancing the working efficiency of the blade.

[0053] As Figure 4 shown, the value range of the angle α between the left hypotenuse of the groove and the positive X-axis is 0° ≤ α ≤ 135°. If the value of α is relatively small, the oil-gas two-phase flow will enter the groove more smoothly, reducing the turbulence intensity inside the groove, but it may lead to a reduction in the internal space of the groove, restricting the mixing effect of oil and gas; if the value of α is relatively large, the groove has a larger internal space, which helps the fluid to be more evenly distributed and flow, alleviating the pressure fluctuations caused by unstable flow; AsFigure 4 As shown, the range of the angle β between the right inclined side of the groove and the negative X-axis is 0° ≤ β ≤ 135°. If the value of β is relatively small, the space of the groove is relatively small, which not only limits the residence and mixing time of the fluid, but also makes the vortex flow generated in the groove more likely to flow into the mainstream area, reducing the effective suppression of the leakage flow, and thus is not conducive to improving the working conditions of the impeller; if the value of β is relatively large, the groove space is increased, the residence time and flow space of the fluid in the groove are expanded, which helps to slow down the flow velocity of the fluid and effectively reduce the intensity of the leakage eddy current.

[0054] Based on the design of the trapezoidal groove structure, the present invention aims to effectively reduce the vibration and noise of the hybrid pump by precisely regulating the fluid flow path. The dimensions of the groove, such as the top width, bottom width, depth, and angle, have a direct impact on the vibration and noise. A larger top width of the groove can effectively reduce the occurrence probability of the tip separation vortex, thereby reducing the flow instability caused by the vortex, which is usually one of the sources of vibration. By optimizing the geometric shape of the groove, the fluid flow becomes smoother, reducing the impact force and the pressure fluctuation generated by the fluid impacting the impeller surface, and thus reducing the vibration caused by the pressure fluctuation.

[0055] In addition, the bottom width and depth of the groove have an important impact on the flow characteristics of the fluid. A larger bottom width and depth of the groove can accommodate more fluid and provide a larger flow space, thereby reducing the flow velocity and slowing down the turbulence intensity of the fluid. This helps to reduce the noise caused by turbulence and at the same time reduces the micro-vibration caused by turbulence on the impeller surface, further reducing the vibration intensity. The trapezoidal groove can also act as an acoustic barrier by changing the fluid flow path, effectively absorbing and scattering the sound energy, reducing the reflection and propagation of sound waves in the pump, and thus significantly reducing the radiation noise of the pump.

[0056] In summary, the size optimization of the trapezoidal groove structure comprehensively reduces vibration and noise, and improves the working stability and operation efficiency of the hybrid pump by suppressing the generation of eddy currents, reducing fluid turbulence, reducing pressure pulsation, and improving the sound wave propagation path.

[0057] Example 5 This example discloses an oil-gas hybrid pump, which includes a housing 3, an impeller 1 and a diffuser 2 arranged in the housing 3. The impeller 1 is composed of an impeller hub 4 and impeller blades 5 of any one of Examples 1-3.

[0058] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the protection scope of the present invention.

[0059] In the description of the present invention, it should also be noted that unless otherwise clearly specified and defined, the terms "arranged", "installed", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0060] The above are only the preferred embodiments of the present invention, and do not impose any formal limitations on the present invention. Any simple modifications and equivalent changes made to the above embodiments based on the technical essence of the present invention all fall within the protection scope of the present invention.

Claims

1. A structure for suppressing the tip leakage flow of an oil-gas multiphase pump, characterized in that It includes impeller blades, and a groove is provided at the top of the impeller blades. The projection of the groove in a plane perpendicular to the camber line direction of the impeller blades is trapezoidal.

2. The oil-gas mixed transportation pump blade tip leakage flow suppression structure according to claim 1, wherein The groove is provided at the top of the impeller blades and extends radially outward.

3. The suppression structure for tip leakage flow of the oil-gas mixed transportation pump according to claim 1, wherein, The top of the impeller blades has a leading edge and a trailing edge in the circumferential direction, and a plurality of the grooves are arranged along the direction from the leading edge to the trailing edge.

4. The oil-gas mixed transportation pump blade tip leakage flow suppression structure according to claim 1, characterized in that, The top of the impeller blades has a leading edge and a trailing edge, and the groove extends along the circumferential direction of the impeller blades, starting from the leading edge and ending at the trailing edge.

5. The oil-gas mixed transportation pump blade tip leakage flow suppression structure according to claim 1, characterized in that, The ratio of the top width of the groove to the thickness of the impeller blades is 0.2 - 0.

8.

6. The oil-gas multiphase pump tip leakage flow suppression structure according to claim 1, wherein The ratio of the bottom width of the groove to the thickness of the impeller blades is 0.2 - 0.

9.

7. The oil-gas mixed transportation pump blade tip leakage flow suppression structure according to claim 1, characterized in that The ratio of the depth of the groove to the thickness of the impeller blades is 0.2 - 1.

2.

8. The suppression structure for the tip leakage flow of the oil-gas multiphase pump according to claim 1, wherein The range of the angle α between the left inclined side of the groove and the straight line where the top line segment of the impeller blade is located is 0° - 135°.

9. The suppression structure for the tip leakage flow of the oil-gas mixed transportation pump according to claim 1, wherein The range of the angle β between the right inclined side of the groove and the straight line where the top line segment of the impeller blade is located is 0° - 135°.

10. A design method for the tip leakage flow suppression structure of an oil-gas multiphase pump according to any one of claims 1-9, characterized in that, It includes the following steps: Step A. Set a plane, and the plane is perpendicular to the camber line direction of the impeller blades; on the plane, set an X-axis and a Y-axis respectively. The X-axis coincides with the straight line where the top line segment of the impeller blade is located, and the Y-axis passes through the camber line of the blade and is perpendicular to the X-axis at point O. Step B. Design a groove at the top of the impeller blades. The projection of the groove in the set plane is trapezoidal and the projection is symmetric about the Y-axis. Step C. Determine the groove parameters according to the flow rate, rotational speed and head of the oil-gas multiphase pump, including the top width b of the groove, the bottom width c of the groove, the depth h of the groove, the angle α between the left inclined side of the groove and the positive direction of the X-axis, and the angle β between the right inclined side of the groove and the negative direction of the X-axis. Step D. Apply the groove parameters determined in Step C to the designed impeller blades, and finally complete the design of the impeller blades of the oil-gas multiphase pump.

11. An oil-gas mixed transportation pump, characterized in that, It includes a housing and an impeller and a diffuser arranged in the housing. The impeller is composed of an impeller hub and the impeller blades according to any one of claims 1 - 9.

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