CN113931847A

CN113931847A - Reversible counter-rotating axial flow pump

Info

Publication number: CN113931847A
Application number: CN202111118245.0A
Authority: CN
Inventors: 孙帅辉; 朱国俊; 郭鹏程; 董勇; 张祯
Original assignee: Xian University of Technology
Current assignee: Xian University of Technology
Priority date: 2021-09-23
Filing date: 2021-09-23
Publication date: 2022-01-14

Abstract

The invention discloses a reversible counter-rotating axial-flow pump which comprises a front guide vane, a front impeller, a rear impeller and a rear guide vane which are positioned on the same straight line and arranged in sequence, wherein the front guide vane and the front impeller are in mirror symmetry with the rear impeller and the rear guide vane, and the front impeller and the rear impeller have the same rotating speed and opposite rotating directions. The reversible counter-rotating axial-flow pump is provided with the two impellers which are opposite in rotation direction and completely symmetrical, when fluid flows out of the front impeller, the rear impeller recovers part of kinetic energy at the outlet of the front impeller, and meanwhile secondary work is performed on the fluid, so that the overall lift of the water pump is improved, and the efficient operation range of the water pump is enlarged. In reverse operation, the water pump also has the same operational capacity. The invention can realize bidirectional operation, reduce the size and weight of the pump body, and has compact structure and small occupied space.

Description

Reversible counter-rotating axial flow pump

Technical Field

The invention belongs to the technical field of fluid machinery, and particularly relates to a reversible counter-rotating axial-flow pump.

Background

The axial-flow pump utilizes the lift force generated by the rotation of the airfoil blades of the rotating impeller in the fluid to enable the fluid to obtain energy for the occasions with high flow and low lift, and has the characteristics of simple structure, convenient use and wide practical application. However, in some applications of the axial flow pump, the requirements of high lift and reversible operation may occur, and the conventional axial flow pump is difficult to meet the requirements. Although there has been a counter-rotating impeller design to increase its overall head, there has been no report on the design of a high-lift axial flow pump capable of reversible operation, and the relevant design theory is unclear.

Disclosure of Invention

The invention aims to provide a reversible counter-rotating axial flow pump, which solves the problem that the conventional axial flow pump is difficult to meet the requirements of high lift and reversible operation.

The technical scheme adopted by the invention is as follows: the reversible counter-rotating axial-flow pump comprises a front guide vane, a front impeller, a rear impeller and a rear guide vane which are positioned on the same straight line and are sequentially arranged, wherein the front guide vane and the front impeller are in mirror symmetry with the rear impeller and the rear guide vane, and the front impeller and the rear impeller have the same rotating speed and opposite rotating directions.

The present invention is also characterized in that,

the wing profiles of the front impeller and the rear impeller are symmetrical wing profiles and are symmetrical about the center of the wing profiles.

The wing profiles of the front impeller and the rear impeller are S-shaped.

The distance between the front impeller and the rear impeller is 30-100% of the outer diameter of the front impeller or the rear impeller.

The circumference of the front impeller is provided with a front rim motor, and the circumference of the rear impeller is provided with a rear rim motor. The front impeller and the rear impeller are driven by independent motors, and can be driven by a rim motor or a motor arranged in a hub.

The blade wing profiles of the front guide blade and the rear guide blade are straight guide blades.

The number of the blades of the front guide vane and the rear guide vane is more than two.

One end of the front guide vane far away from the front impeller is coaxially connected with a front guide cone, and one end of the rear guide vane far away from the rear impeller is coaxially connected with a rear guide cone.

The invention has the beneficial effects that: the reversible counter-rotating axial-flow pump is provided with the two impellers which are opposite in rotation direction and completely symmetrical, when fluid flows out of the front impeller, the rear impeller recovers part of kinetic energy at the outlet of the front impeller, and meanwhile secondary work is performed on the fluid, so that the overall lift of the water pump is improved, and the efficient operation range of the water pump is enlarged. In reverse operation, the water pump also has the same operational capacity. The invention can realize bidirectional operation, reduce the size and weight of the pump body, and has compact structure and small occupied space.

Drawings

FIG. 1 is a schematic view of a reversible counter-rotating axial flow pump according to the present invention;

FIG. 2 is a schematic diagram of a three-dimensional model of a reversible counter-rotating axial flow pump according to the present invention;

fig. 3 is a schematic structural diagram of a front impeller and a rear impeller in a reversible counter-rotating axial-flow pump according to the present invention.

In the figure, 1 is a front guide cone, 2 is a front guide vane, 3 is a front impeller, 4 is a rear impeller, 5 is a rear guide vane, 6 is a rear guide cone, 7 is a front rim motor, and 8 is a rear rim motor.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

The invention provides a reversible counter-rotating axial-flow pump, as shown in figures 1 and 2, comprising a front guide cone 1, a front guide vane 2, a front impeller 3, a rear impeller 4, a rear guide vane 5 and a rear guide cone 6 which are positioned on the same straight line and are sequentially arranged, wherein the front guide vane 2 and the front impeller 3 are in mirror symmetry with the rear impeller 4 and the rear guide vane 5, the distance between the front impeller 3 and the rear impeller 4 is 30-100% of the outer diameter of the front impeller 3 or the rear impeller 4, a front rim motor 7 is arranged in the circumferential direction of the front impeller 3, a rear rim motor 8 is arranged in the circumferential direction of the rear impeller 4, the motors can be arranged in a wheel hub for driving, the rotating speeds of the front impeller 3 and the rear impeller 4 are the same and the rotating directions are opposite, so that the rear impeller 4 can recover part of kinetic energy at the outlet of the front impeller 3 and do secondary work for fluid, thereby improving the integral lift of the water pump and meeting the operation requirement. The invention can meet the requirements of the reversible high-lift axial-flow pump, effectively reduce the size of the pump body, simplify the complexity of a conveying system and the number of pipelines, and reduce the weight and the requirements of installation space.

As shown in fig. 3, the airfoils of the front impeller 3 and the rear impeller 4 are symmetrical airfoils and symmetrical about the center of the airfoils, preferably S airfoils, and this type of design is adopted to ensure the requirement of reversible operation and to ensure that the operation performance of the pump is substantially consistent during bidirectional operation. The blade wing type of leading stator 2 and rearmounted stator 5 is straight stator and all sets up more than two, mainly plays the effect of supporting and two-way water conservancy diversion.

When the water pump works, when the water pump works in the forward direction, fluid flows from left to right, the front guide vane 2 uniformly guides the fluid to the front guide vane 3, the front guide vane 3 rotates anticlockwise to apply work to the fluid, the rear guide vane 4 rotates clockwise to recover partial energy at the outlet of the front guide vane 3, the fluid applies work for the second time, and the whole lift of the water pump is improved. The rear guide vane 5 recovers part of energy of fluid flowing out of the rear impeller 4, and the overall efficiency is improved; when the water pump runs reversely, fluid flows from right to left, the rear guide vane 5 uniformly guides the fluid into the rear impeller 4, the rear impeller 4 rotates anticlockwise to apply work to the fluid, the front impeller 3 rotates clockwise to recover partial energy at the outlet of the rear impeller 4, the fluid applies work for the second time, and the overall lift of the water pump is improved. The front guide vane 2 recovers part of energy of the outflow fluid of the front impeller 3. Because the impeller adopts S type wing type, the stator adopts straight stator wing type, and leading stator 2, leading impeller 3 and rear impeller 4, rear stator 5 are complete symmetry, have guaranteed like this when the reverse motion, the water pump also can keep the same high efficiency when the forward motion. The hydraulic performance is better under the reversible operation condition with high lift. When the impeller runs reversely, only the outlet in the forward running is changed into an inlet, the inlet is changed into an outlet, and meanwhile, the rotation directions of the front impeller 3 and the rear impeller 4 are set to be opposite.

Through the mode, the reversible counter-rotating axial flow pump provided by the invention has the advantages that the operation range of a common axial flow pump is enlarged, the total lift of the pump is effectively improved, and the pump body is smaller in size and more compact in structure under the same design condition. It also has the lift and efficiency of its forward operation in reverse operation. The device is suitable for occasions with large flow, high lift and bidirectional operation. Through simulation calculation, the lift, the efficiency and the shaft power are the same when the engine runs in the forward direction and runs in the reverse direction, and the engine has higher efficiency.

Claims

1. The reversible counter-rotating axial-flow pump is characterized by comprising a front guide vane (2), a front impeller (3), a rear impeller (4) and a rear guide vane (5) which are positioned on the same straight line and are sequentially arranged, wherein the front guide vane (2) and the front impeller (3) are in mirror symmetry with the rear impeller (4) and the rear guide vane (5), and the rotating speeds of the front impeller (3) and the rear impeller (4) are the same and the rotating directions are opposite.

2. A contra-rotating reversible axial flow pump according to claim 1, characterized in that the airfoils of the leading impeller (3) and the trailing impeller (4) are symmetrical airfoils and are symmetrical about the airfoil center.

3. A contra-rotating reversible axial flow pump according to claim 1 or 2, characterized in that the leading impeller (3) and the trailing impeller (4) are S-shaped in their airfoil profile.

4. A counter-rotating reversible axial flow pump according to claim 1, characterized in that the distance between the front impeller (3) and the rear impeller (4) is 30% to 100% of the outer diameter of the front impeller (3) or the rear impeller (4).

5. A contra-rotating reversible axial flow pump according to claim 1, characterized in that the leading impeller (3) is circumferentially provided with a leading rim motor (7) and the trailing impeller (4) is circumferentially provided with a trailing rim motor (8).

6. A counter-rotating reversible axial flow pump according to claim 1, characterized in that the blade profiles of the front guide vane (2) and the rear guide vane (5) are straight guide vanes.

7. A counter-rotating reversible axial flow pump according to claim 1 or 6, characterized in that the number of the vanes of the front guide vane (2) and the rear guide vane (5) is two or more.

8. A reversible counter-rotating axial-flow pump according to claim 1, characterized in that the end of the front guide vane (2) far from the front impeller (3) is coaxially connected with a front guide cone (1), and the end of the rear guide vane (5) far from the rear impeller (4) is coaxially connected with a rear guide cone (6).