An impeller of an efficient anti-gas-lock multiphase pump

Abstract

The present invention discloses an impeller of an efficient anti-gas-stagnation multiphase mixed-flow pump, which includes a hub and a rim. An annular partition is provided between the hub and the rim. The partition divides the flow passage of the pump into an inner section and an outer section. A through jet hole is provided on the partition at the end of the outer blade. The jet hole is located between two outer blades. An anti-gas-stagnation blade is provided on the hub at the end of the inner blade. The anti-gas-stagnation blade is located between two inner blades. The profile line of the anti-gas-stagnation blade is consistent with the back profile line of the inner blade. Both the inner and outer sides of the partition are of negative curvature structure. The traditional single flow passage is radially divided into an inner and an outer double flow passage structure, avoiding the excessive pressure gradient caused by the too large flow passage of the mixed-flow pump impeller, thereby reducing the degree of gas-liquid separation in the flow passage to a certain extent. In addition, both the inner and outer sides of the partition adopt a negative curvature structure, generating a curvature centrifugal force opposite to the direction of the rotational centrifugal force to balance part of the centrifugal force, further reducing the degree of gas-liquid separation and reducing the gas phase aggregation phenomenon.

Description

Technical Field

[0001] The present invention relates to a screw axial multi-phase mixed transportation pump, in particular to an impeller of a high-efficiency gas-stagnation prevention type multi-phase mixed transportation pump. Background Art

[0002] In the fields of deep-sea oil and gas exploitation, oil and gas pipeline transportation, and oil and gas gathering and transportation pipe networks, the multi-phase mixed transportation pump is one of the core equipments. The screw axial multi-phase mixed transportation pump has become an ideal choice for the current and future periods due to its advantages such as simple and compact structure and suitability for transporting large-flow gas-liquid mixed media. However, in actual operation, especially under the condition of medium and high gas volume fractions, the transportation efficiency of the mixed transportation pump decreases significantly. The main reason is the gas-liquid separation and gas-phase retention problems caused by the internal flow characteristics of the impeller. Research shows that the radial pressure gradient in the rotating impeller is the main cause of gas-liquid separation. Due to the density difference between the gas and liquid phases, the gas accumulates towards the center of the impeller under the action of centrifugal force, while the liquid is thrown to the outer edge, forming a gas-liquid separation phenomenon. In addition, the gas-phase retention caused by the reverse pressure gradient further exacerbates the flow instability and reduces the transportation efficiency of the pump. These problems not only lead to energy loss, but also cause vibration, noise and cavitation, seriously affecting the reliability and service life of the pump. Summary of the Invention

[0003] The purpose of the present invention is to provide an impeller of a high-efficiency gas-stagnation prevention type multi-phase mixed transportation pump to solve the technical problem of intermittent flow channel blockage caused by gas accumulation at the trailing edge of the blade in the prior art.

[0004] The technical solution adopted by the present invention to solve its technical problems is: an impeller of a high-efficiency gas-stagnation prevention type multi-phase mixed transportation pump, including a hub and a rim, and blades located between the hub and the rim. An annular partition is provided between the hub and the rim. The partition divides the flow channel of the pump into an inner section and an outer section. The blades in the inner section are inner blades, and the blades in the outer section are outer blades. A through jet hole is provided on the partition at the end of the outer blade. The jet hole is located between two outer blades. An anti-gas-stagnation blade is provided on the hub at the end of the inner blade. The anti-gas-stagnation blade is located between two inner blades. The profile of the anti-gas-stagnation blade is consistent with the back profile of the inner blade. Both the inner and outer sides of the partition are of negative curvature structure.

[0005] Further improvement: When L1 is the length of the blade profile, in the flow direction, the distance L2 from the jet hole to the front end of the outer blade is L2=(0.7~0.9)L1, in the direction perpendicular to the flow direction, the distance L3 between the jet hole and the outer blade is L3 = 1~2mm, and the aperture of the jet hole is 1~3mm.

[0006] Further improvement: The length L4 of the anti-gas-stagnation blade is (0.1 - 0.3)L1. In the direction perpendicular to the flow direction, the distance L5 between the front end of the anti-gas-stagnation blade and the inner blade is 1 - 2 mm. In the flow direction, the distance L6 from the front end of the anti-gas-stagnation blade to the front end of the inner blade is (0.7 - 0.9)L1. The deflection angle α between the anti-gas-stagnation blade and the end of the inner blade is 4 - 6°.

[0007] Further improvement: Both the outer side of the hub and the inner side of the rim have negative curvature, and the curvature radius R2 of the hub, the partition plate, and the rim is (2 - 2.4)R1, where R1 is the rim radius.

[0008] Advantages of the present invention: The traditional single flow channel is radially divided into an inner and an outer two-flow-channel structure, which avoids the excessive pressure gradient caused by the too large flow channel of the mixed transport pump impeller, thereby reducing the degree of gas-liquid separation in the flow channel to a certain extent. In addition, both the inner and outer sides of the partition plate adopt a negative curvature structure, generating a curvature centrifugal force opposite to the direction of the rotational centrifugal force to balance part of the centrifugal force, further reducing the degree of gas-liquid separation and reducing the gas-phase aggregation phenomenon.

[0009] In the inner flow channel structure, an anti-gas-stagnation blade is arranged at the end section of the inner blade. The anti-gas-stagnation blade can convert the adverse pressure gradient at the tail end of the inner blade into a favorable pressure gradient. The favorable pressure gradient force can push out the gas accumulated at the trailing edge of the inner blade, avoiding gas blockage in the inner flow channel.

[0010] In the outer flow channel structure, by arranging jet holes at the end section of the outer blade, part of the inner-section jet fluid is guided to the gas-phase aggregation area in the outer section, and the jet is used to impact the gas stagnation in the outer section, thereby effectively avoiding gas blockage in the outer flow channel.

[0011] In summary, the present invention adopts different control strategies for the inner and outer two flow channels, avoiding the intermittent flow channel blockage caused by gas accumulation at the trailing edge of the blade. Description of the Drawings

[0012] Figure 1 is a schematic structural diagram of the present invention.

[0013] Figure 2 is a schematic structural diagram of the outer section of the present invention.

[0014] Figure 3 is a schematic structural diagram of the inner section of the present invention.

[0015] Figure 4 is a schematic diagram of the position of the jet holes of the present invention.

[0016] Figure 5 is a schematic diagram of the position of the anti-gas-stagnation blade of the present invention.

[0017] Figure 6It is an axial sectional view of the hub, partition plate and rim of the present invention.

[0018] In the figure: hub 1, rim 2, partition plate 3, outer section 4, outer blade 5, jet hole 6, inner section 7, inner blade 8, anti-air stagnation blade 9. Detailed implementation manner

[0019] The following makes a detailed description of the present invention in conjunction with the attached drawings of the specification.

[0020] As Figures 1 - 6 shown, a high-efficiency anti-air stagnation type multiphase mixed-flow pump impeller includes a hub 1 and a rim 2, and blades located between the hub 1 and the rim 2. An annular partition plate 3 is provided between the hub 1 and the rim 2. The partition plate 3 divides the flow passage of the pump into an inner section 7 and an outer section 4. The blades located in the inner section 7 are inner blades 8, and the blades located in the outer section 4 are outer blades 5. A through jet hole 6 is provided on the partition plate 3 at the end of the outer blade 5. The jet hole 6 is located between two outer blades 5. An anti-air stagnation blade 9 is provided on the hub 1 at the end of the inner blade 8. The anti-air stagnation blade 9 is located between two inner blades 8. The profile of the anti-air stagnation blade 9 is consistent with the back profile of the inner blade 8. Both the inner and outer sides of the partition plate 3 are negative curvature structures.

[0021] When L1 is the length of the blade profile, in the flow direction, the distance L2 from the jet hole 6 to the front end of the outer blade 5 = (0.7 - 0.9)L1. In the direction perpendicular to the flow direction, the distance L3 between the jet hole 6 and the outer blade 5 = 1 - 2 mm, and the aperture of the jet hole 6 is 1 - 3 mm.

[0022] The length L4 of the anti-air stagnation blade 9 = (0.1 - 0.3)L1. In the direction perpendicular to the flow direction, the distance L5 between the front end of the anti-air stagnation blade 9 and the inner blade 8 = 1 - 2 mm. In the flow direction, the distance L6 from the front end of the anti-air stagnation blade 9 to the front end of the inner blade 8 = (0.7 - 0.9)L1. The deflection angle α between the anti-air stagnation blade 9 and the end of the inner blade 8 = 4 - 6°.

[0023] Both the outer side of the hub 1 and the inner side of the rim 2 are negative curvature, where the radius of curvature R2 of the hub 1, partition plate 3, and rim 2 = (2 - 2.4)R1, and R1 is the rim radius.

[0024] Its working principle is as follows: Through the innovative double-channel structure, negative-curvature partition 3, anti-air-stagnation blades 9, and jet holes 6 design, the present invention systematically solves the problems of gas-liquid separation and gas blockage in the impeller flow channel of the hybrid pump. After the gas-liquid mixed fluid enters the impeller flow channel, it is radially divided into two inner and outer double channels for separate treatment. This partition design reduces the size of a single flow channel, lowers the pressure gradient, and avoids gas-liquid separation and gas-phase accumulation caused by an overly large flow channel. The inner and outer sides of the partition 3 adopt a negative-curvature structure, generating a curvature centrifugal force opposite to the direction of the rotational centrifugal force, balancing part of the centrifugal force, and further reducing the degree of gas-liquid separation. In the inner-section 7 flow channel, the anti-air-stagnation blades 9 convert the adverse pressure gradient at the trailing end of the inner blades 8 into a favorable pressure gradient, and the favorable pressure gradient force pushes out the accumulated gas, avoiding gas blockage in the inner-section 7 flow channel; in the outer-section 4 flow channel, the jet holes 6 guide part of the inner-section 7 jet fluid to the gas-phase accumulation area, and use the jet impact to break up the air-stagnant gas, avoiding gas blockage in the outer-section 4 flow channel. Finally, the treated gas-liquid mixed fluid is output from the flow channel, avoiding gas-liquid separation and gas blockage, and improving the operation efficiency and stability of the hybrid pump.

[0025] The above are only the embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be similarly included in the patent protection scope of the present invention.

Claims

1. An efficient anti-gas stagnation type multiphase mixed pump impeller, comprising a hub and a rim, and blades located between the hub and the rim, characterized in that: An annular partition is provided between the wheel hub and the wheel rim, the partition divides the flow channel of the pump into an inner section and an outer section, the blades located in the inner section are inner blades, and the blades located in the outer section are outer blades, a penetrating jet hole is provided on the partition at the end section of the outer blade, the jet hole is located between the two outer blades, an anti-gas stagnation blade is provided on the wheel hub at the end section of the inner blade, the anti-gas stagnation blade is located between the two inner blades, the profile of the anti-gas stagnation blade is consistent with the back profile of the inner blade, and the deflection angle between the anti-gas stagnation blade and the end of the inner blade is α =4~6°, both the inner and outer sides of the partition are negative curvature structures; when L1 is the blade profile length, in the flow direction, the distance from the jet hole to the front end of the outer blade is L2=(0.7~0.9)L1, in the vertical flow direction, the distance between the jet hole and the outer blade is L3=1~2mm, and the aperture of the jet hole is 1~3mm; the outer side of the hub and the inner side of the rim are negative curvatures, wherein the curvature radius of the hub, partition and rim is R2=(2~2.4)R1, and R1 is the rim radius.

2. The high-efficiency anti-gas stagnation type multiphase mixed pump impeller according to claim 1 is characterized in that: The length of the anti-stagnation blade is L4=(0.1~0.3)L1. In the direction perpendicular to the flow, the distance between the front end of the anti-stagnation blade and the inner blade is L5=1~3mm. In the flow direction, the distance from the front end of the anti-stagnation blade to the front end of the inner blade is L6=(0.7~0.9)L1.

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