Screw axial flow pump

Abstract

This invention discloses a helical axial flow pump, comprising a stator, a rotor, a first liquid-collecting speed-reducing turbine, and a second liquid-collecting speed-reducing turbine. The first and second liquid-collecting speed-reducing turbines are connected to both ends of the stator, respectively. Multiple first helical grooves are evenly distributed on the inner circumferential surface of the stator. The rotor is rotatably disposed within the stator and located between the first and second liquid-collecting speed-reducing turbines. Multiple second helical grooves are evenly distributed on the outer circumferential surface of the rotor, with the second helical grooves rotating in the opposite direction to the first helical grooves. Each second helical groove has a radial suction hole at its end near the first liquid-collecting speed-reducing turbine, and each radial suction hole communicates inwardly with the inner discharge ring groove of the first liquid-collecting speed-reducing turbine. The end of each second helical groove near the second liquid-collecting speed-reducing turbine communicates with the liquid inlet channel of the second liquid-collecting speed-reducing turbine. This invention is suitable for transporting high-viscosity gas-liquid mixtures. The rotor has good overall structural rigidity, solving the dynamic balance problem of radially cast impellers in conventional submersible centrifugal pumps, and is suitable for medium- and high-speed operation.

Description

Technical Field

[0001] This invention relates to the field of submersible electric pump oil extraction technology, and in particular to a spiral axial flow pump. Background Technology

[0002] Submersible electric pumps (SAPs) are a well-established and mature tool for rodless oil production. They are commonly used for high-volume oil production on land and offshore platforms and have advantages such as small footprint, no noise, and ease of management.

[0003] However, transporting high-viscosity gas-liquid mixtures presents a challenge. At high speeds, the powerful centrifugal force also poses a significant challenge to the radially curved blades. Summary of the Invention

[0004] The purpose of this invention is to provide a spiral axial flow pump to solve the problems existing in the prior art. It is suitable for transporting gas-liquid mixtures with high viscosity, has good overall rotor rigidity, solves the dynamic balance problem of radial cast impellers in conventional submersible centrifugal pumps, and is suitable for medium and high speed operation.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] This invention provides a helical axial flow pump, including a stator, a rotor, a first liquid collecting and decelerating turbine, and a second liquid collecting and decelerating turbine. The stator is connected to the first liquid collecting and decelerating turbine and the second liquid collecting and decelerating turbine at its two ends, respectively. The inner circumferential surface of the stator is uniformly provided with a plurality of first helical grooves. The rotor is rotatably disposed within the stator and located between the first liquid collecting and decelerating turbine and the second liquid collecting and decelerating turbine. The outer circumferential surface of the rotor is uniformly provided with a plurality of second helical grooves. The second helical grooves rotate in the opposite direction to the first helical grooves. Each second helical groove has a radial suction hole at one end near the first liquid collecting and decelerating turbine. Each radial suction hole communicates inward with the inner discharge ring groove of the first liquid collecting and decelerating turbine. The end of each second helical groove near the second liquid collecting and decelerating turbine communicates with the inlet channel of the second liquid collecting and decelerating turbine.

[0007] Preferably, the first spiral groove is a serrated spiral groove with a right-hand spiral direction; the second spiral groove is a semi-circular spiral groove with a left-hand spiral direction; and the spiral direction of the axial guide vanes of the first liquid collecting and decelerating turbine and the second liquid collecting and decelerating turbine is consistent with the spiral direction of the first spiral groove.

[0008] Preferably, the sawtooth angle of the sawtooth spiral groove is 45° to 60°, and the helix angle of the second spiral groove is 15° to 25°.

[0009] Preferably, the rotor has an annular positioning groove at one end near the first liquid collecting and decelerating turbine, and the annular positioning groove is slidably connected to an annular positioning protrusion on the first liquid collecting and decelerating turbine; the rotor has a positioning and straightening step at one end near the second liquid collecting and decelerating turbine, and the positioning and straightening step is slidably connected to the center hole of the second liquid collecting and decelerating turbine.

[0010] Preferably, the axial clearance of the rotor in the space formed by the first liquid collecting and decelerating turbine, the second liquid collecting and decelerating turbine, and the stator is 1 to 2 mm, and the radial clearance between the rotor and the stator is 0.4 to 0.8 mm.

[0011] Preferably, the rotor has a shaft connection hole with a keyway inside.

[0012] Preferably, the stator has an outer stator step that mates with the inner turbine step on the first liquid collecting and decelerating turbine at one end, and an inner stator step that mates with the outer turbine step on the second liquid collecting and decelerating turbine at one end.

[0013] Preferably, the number of the first spiral grooves is odd, the number of the second spiral grooves is even, and the number of axial guide vanes of both the first liquid collecting and decelerating turbine and the second liquid collecting and decelerating turbine is odd.

[0014] Preferably, the axial guide vanes of both the first liquid collecting and decelerating turbine and the second liquid collecting and decelerating turbine are semi-open axial guide vanes.

[0015] The present invention achieves the following technical effects compared to the prior art:

[0016] This invention provides a helical axial flow pump. The rotor rotates at high speed driven by the pump shaft, with the rotation direction opposite to that of the second helical groove. Liquid is drawn in through the radial suction hole via the first liquid collecting and speed-reducing turbine and centrifugally thrown out into the groove gap between the second helical groove of the rotor and the first helical groove of the stator. The groove edges move and violently rub and shear, breaking large bubbles into small bubbles, which mix into the liquid. Under the pumping of the inner and outer grooves of the stator and rotor, the liquid is axially discharged through the second liquid collecting and speed-reducing turbine. The first liquid collecting and speed-reducing turbine and the second liquid collecting and speed-reducing worm gear mainly reduce the radial velocity of the axial liquid, converting dynamic energy into static pressure energy. This combines a centrifugal pump and an axial flow pump, making it suitable for transporting gas-liquid mixtures with high viscosity. The rotor has good overall structural rigidity, solving the dynamic balance problem of the radial cast impeller of conventional submersible centrifugal pumps, and is suitable for medium and high speed operation. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A three-dimensional structural schematic diagram of the spiral axial flow pump provided by the present invention;

[0019] Figure 2 A cross-sectional view of the spiral axial flow pump provided by the present invention;

[0020] Figure 3 This is a three-dimensional structural diagram of the rotor in this invention;

[0021] Figure 4 This is a front view of the rotor in this invention;

[0022] Figure 5 for Figure 4 AA section view of the central rotor;

[0023] Figure 6 This is a three-dimensional structural diagram of the stator in this invention;

[0024] Figure 7 This is a cross-sectional view of the stator in this invention;

[0025] Figure 8 This is a three-dimensional structural diagram of the first liquid collecting and decelerating turbine and the second liquid collecting and decelerating turbine in this invention.

[0026] Figure 9 This is a cross-sectional view of the first liquid collecting and decelerating turbine and the second liquid collecting and decelerating turbine in this invention.

[0027] In the diagram: 100-Helical axial flow pump, 1-Stator, 2-Rotor, 3-First liquid collecting and speed reducing turbine, 4-Second liquid collecting and speed reducing turbine, 5-First helical groove, 6-Second helical groove, 7-Radial suction hole, 8-Inner discharge ring groove, 9-Liquid inlet channel, 10-Axial guide vane, 11-Annular positioning groove, 12-Annular positioning protrusion, 13-Positioning and straightening step, 14-Center hole, 15-Shaft connection hole, 16-Turbine inner step, 17-Stator outer step, 18-Turbine outer step, 19-Stator inner step. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] The purpose of this invention is to provide a spiral axial flow pump to solve the problems existing in the prior art. It is suitable for transporting gas-liquid mixtures with high viscosity, has good overall rotor rigidity, solves the dynamic balance problem of radial cast impellers in conventional submersible centrifugal pumps, and is suitable for medium and high speed operation.

[0030] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] like Figures 1-9 As shown, this embodiment provides a spiral axial flow pump 100, including a stator 1, a rotor 2, a first liquid collecting and decelerating turbine 3, and a second liquid collecting and decelerating turbine 4. The first liquid collecting and decelerating turbine 3 and the second liquid collecting and decelerating turbine 4 are respectively connected to both ends of the stator 1. Multiple first spiral grooves 5 are uniformly provided on the inner circumferential surface of the stator 1. The rotor 2 is rotatably disposed in the stator 1 and located between the first liquid collecting and decelerating turbine 3 and the second liquid collecting and decelerating turbine 4. Multiple second spiral grooves 6 are uniformly provided on the outer circumferential surface of the rotor 2. The spiral direction of the second spiral grooves 6 is opposite to that of the first spiral grooves 5. Each second spiral groove 6 has a radial suction hole 7 at one end near the first liquid collecting and decelerating turbine 3. Each radial suction hole 7 communicates inward with the inner discharge ring groove 8 of the first liquid collecting and decelerating turbine 3. Each second spiral groove 6 has a liquid inlet channel 9 near the second liquid collecting and decelerating turbine 4 at one end.

[0032] During operation, rotor 2 rotates at high speed driven by the pump shaft, with the rotation direction opposite to that of the second spiral groove 6. Liquid is drawn in through the radial suction hole 7 via the first liquid collecting and speed reducing turbine 3, and centrifugally ejected into the groove gap between the second spiral groove 6 of rotor 2 and the first spiral groove 5 of stator 1, increasing the suction pressure. Simultaneously, during the high-speed relative motion between the stator and rotor, the groove edges collide and violently rub and shear, breaking large bubbles into small bubbles, which are then mixed with the liquid, resulting in a uniform gas-liquid mixture. Under the pumping action of the inner and outer grooves of stator 1 and rotor 2, the liquid is axially discharged through the second liquid collecting and speed reducing turbine 4. The first liquid collecting and speed reducing turbine 3 and the second liquid collecting and speed reducing worm gear 4 mainly reduce the radial velocity of the axial liquid, converting dynamic energy into static pressure energy. This combines the functions of a centrifugal pump and an axial flow pump, making it suitable for transporting gas-liquid mixtures with higher viscosity. The rotor has good overall structural rigidity, solving the dynamic balance problem of the radial cast impeller in conventional submersible centrifugal pumps, and is suitable for medium- and high-speed operation.

[0033] In this embodiment, the first spiral groove 5 is a sawtooth spiral groove with a right-hand spiral direction; the second spiral groove 6 is a semi-circular spiral groove with a left-hand spiral direction; the spiral direction of the axial guide vanes 10 of the first liquid collecting and decelerating turbine 3 and the second liquid collecting and decelerating turbine 4 is opposite to the spiral direction of the first spiral groove 5, ensuring that the spiral direction of the fluid is opposite to the spiral direction of the axial guide vanes 10, thereby achieving the purpose of deceleration and pressurization.

[0034] In this embodiment, the sawtooth angle of the sawtooth spiral groove is 45° to 60°, preferably 60°, and the helix angle of the second spiral groove 6 is 15° to 25°, preferably 25°.

[0035] In this embodiment, an annular positioning groove 11 is provided at one end of the rotor 2 near the first liquid collecting and decelerating turbine 3, and the annular positioning groove 11 is slidably connected to the annular positioning protrusion 12 on the first liquid collecting and decelerating turbine 3; a positioning and straightening step 13 is provided at one end of the rotor 2 near the second liquid collecting and decelerating turbine 4, and the positioning and straightening step 13 is slidably connected to the center hole 14 of the second liquid collecting and decelerating turbine 4, so as to achieve the function of positioning the rotor 2 within the stator 1. The first liquid collecting and decelerating turbine 3 and the second liquid collecting and decelerating turbine 4 have the same structure.

[0036] In this embodiment, the axial clearance of the rotor 2 within the space formed by the first liquid collecting and speed reducing turbine 3, the second liquid collecting and speed reducing turbine 4, and the stator 1 is 1 to 2 mm, preferably 2 mm, and the radial clearance between the rotor 2 and the stator 1 is 0.4 to 0.8 mm, preferably 0.8 mm.

[0037] In this embodiment, the rotor 2 is provided with a shaft connection hole 15 with a keyway. The pump shaft is connected to the shaft connection hole 15 by a key so as to drive the rotor 2 to rotate.

[0038] In this embodiment, the stator 1 has an outer stator step 17 at the end near the first liquid collecting and decelerating turbine 3, which mates with the inner turbine step 16 on the first liquid collecting and decelerating turbine 3. The stator 1 also has an inner stator step 19 at the end near the second liquid collecting and decelerating turbine 4, which mates with the outer turbine step 18 on the second liquid collecting and decelerating turbine 4. The first liquid collecting and decelerating turbine 3 and the second liquid collecting and decelerating turbine 4 are pressed together with the stator 1 through the inner and outer steps, ensuring the sealing performance at the connection between the first liquid collecting and decelerating turbine 3 and the second liquid collecting and decelerating turbine 4 and the stator 1.

[0039] In this embodiment, the number of first spiral grooves 5 is odd, preferably 7, and the number of second spiral grooves 6 is even, preferably 12. The number of axial guide vanes of the first liquid collecting and speed reducing turbine 3 and the second liquid collecting and speed reducing turbine 4 are both odd, preferably 7. Setting the number of first spiral grooves 5 to odd and the number of second spiral grooves 6 to even makes the balance of the screw rotor easier to adjust and prevents resonance during high-speed operation.

[0040] In this embodiment, the axial guide vanes 10 of both the first liquid collecting and decelerating turbine 3 and the second liquid collecting and decelerating turbine 4 are semi-open axial guide vanes. Using semi-open axial guide vanes facilitates the passage of high-viscosity fluids and gas-liquid mixtures, reducing friction.

[0041] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A spiral axial flow pump, characterized in that: The device includes a stator, a rotor, a first liquid collecting and decelerating turbine, and a second liquid collecting and decelerating turbine. The stator is connected to the first liquid collecting and decelerating turbine and the second liquid collecting and decelerating turbine at its two ends, respectively. The inner circumferential surface of the stator is uniformly provided with multiple first spiral grooves. The rotor is rotatably disposed within the stator and located between the first liquid collecting and decelerating turbine and the second liquid collecting and decelerating turbine. The outer circumferential surface of the rotor is uniformly provided with multiple second spiral grooves. The second spiral grooves have the opposite spiral direction to the first spiral grooves. Each second spiral groove has a radial suction hole at one end near the first liquid collecting and decelerating turbine. Each radial suction hole communicates inward with the inner discharge ring groove of the first liquid collecting and decelerating turbine. The end of each second spiral groove near the second liquid collecting and decelerating turbine communicates with the liquid inlet channel of the second liquid collecting and decelerating turbine. The helical direction of the axial guide vanes of the first liquid collecting and decelerating turbine and the second liquid collecting and decelerating turbine is opposite to the helical direction of the first helical groove; the axial guide vanes of the first liquid collecting and decelerating turbine and the second liquid collecting and decelerating turbine are both semi-open axial guide vanes. The rotor is provided with an annular positioning groove at one end near the first liquid collecting and decelerating turbine, and the annular positioning groove is slidably connected to the annular positioning protrusion on the first liquid collecting and decelerating turbine; the rotor is provided with a positioning and straightening step at one end near the second liquid collecting and decelerating turbine, and the positioning and straightening step is slidably connected to the center hole of the second liquid collecting and decelerating turbine. The stator has an outer stator step at the end near the first liquid collecting and decelerating turbine that mates with the inner turbine step on the first liquid collecting and decelerating turbine, and an inner stator step at the end near the second liquid collecting and decelerating turbine that mates with the outer turbine step on the second liquid collecting and decelerating turbine.

2. The helical axial flow pump according to claim 1, characterized in that: The first spiral groove is a serrated spiral groove with a right-hand spiral direction; the second spiral groove is a semi-circular arc spiral groove with a left-hand spiral direction.

3. The helical axial flow pump according to claim 2, characterized in that: The sawtooth angle of the sawtooth spiral groove is 45°~60°, and the helix angle of the second spiral groove is 15°~25°.

4. The helical axial flow pump according to claim 1, characterized in that: The axial clearance of the rotor within the space formed by the first liquid collecting and decelerating turbine, the second liquid collecting and decelerating turbine, and the stator is 1~2mm, and the radial clearance between the rotor and the stator is 0.4~0.8mm.

5. The helical axial flow pump according to claim 1, characterized in that: The rotor has a shaft connection hole with a keyway inside.

6. The helical axial flow pump according to claim 1, characterized in that: The number of the first spiral groove is odd, the number of the second spiral groove is even, and the number of axial guide vanes of both the first liquid collecting and decelerating turbine and the second liquid collecting and decelerating turbine is odd.

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