阅读说明：本技术 一种轴流泵及其抗空化叶轮 (Axial-flow pump and anti-cavitation impeller thereof ) 是由 赵国寿 曹琳琳 车邦祥 杨帅 吴大转 于 2019-09-30 设计创作，主要内容包括：本发明涉及一种轴流泵及其抗空化叶轮,属于泵技术领域。轴流泵叶轮包括轮毂及固定在轮毂上的叶片；沿叶片的前缘指向其尾缘的方向,在其吸力面的前半部设有一条以上沿该指向间隔布置的空化抑制条,该空化抑制条为长度方向沿展向布置的条状凸起结构。通过在轴流泵叶片的吸力面前半部布置沿展向延伸布置的空化抑制条,从而通过提高抑制条前侧叶面上的压力,以抑制叶片吸力面前缘空化的发生,有效降低前缘空化所引发的振动、噪声与空蚀等危害,可广泛应用于泵、抽水等工程领域中。(The invention relates to an axial flow pump and an anti-cavitation impeller thereof, and belongs to the technical field of pumps. The axial flow pump impeller comprises a hub and blades fixed on the hub; the front half part of the suction surface of the blade is provided with more than one cavitation inhibiting strip which is arranged at intervals along the direction from the front edge of the blade to the tail edge of the blade, and the cavitation inhibiting strip is a strip-shaped convex structure which is arranged along the length direction along the spanwise direction. The cavitation suppression strips which are arranged in a spread-out extending mode are arranged on the front half portion of the suction surface of the axial flow pump blade, so that the pressure on the front side blade surface of the suppression strips is improved, the occurrence of front edge cavitation of the suction surface of the blade is suppressed, the damage of vibration, noise, cavitation and the like caused by the front edge cavitation is effectively reduced, and the axial flow pump blade can be widely applied to the engineering fields of pumps, water pumping and the like.)

1. The utility model provides an anti-cavitation impeller that axial flow pump was used, anti-cavitation impeller includes wheel hub and fixes blade on the wheel hub, its characterized in that:

the front half part of the suction surface of the blade is fixedly provided with more than one cavitation inhibiting strip arranged at intervals along the direction that the front edge of the blade points to the tail edge of the blade, and the cavitation inhibiting strips are strip-shaped convex structures arranged along the spanwise direction of the blade along the length direction.

2. The anti-cavitation impeller of claim 1, wherein:

more than two cavitation suppression strips are distributed on the suction surface; the more than two cavitation inhibiting strips are arranged at intervals along the direction that the front edge points to the tail edge.

3. The anti-cavitation impeller according to claim 1 or 2, characterized in that:

and more than one cavitation suppression strip arranged at intervals along the direction is fixedly arranged at the rear half part of the suction surface, which is adjacent to the tail edge, along the direction of the front edge pointing to the tail edge.

4. The anti-cavitation impeller of claim 3, wherein:

in the front half, a cavitation suppressing strip is arranged in a region ranging from 0.2C to 0.4C from the front edge;

in the rear half, a cavitation suppressing strip is arranged in a region ranging from 0.5C to 0.7C from the front edge;

wherein C is the blade chord length from the leading edge to the trailing edge.

5. The anti-cavitation impeller according to any one of claims 1 to 4, wherein:

in the spanwise direction, the cavitation suppression strip spans the cavitation zone of the blade at its fixed position.

6. The anti-cavitation impeller of claim 5, wherein:

in the spanwise direction, the length of the cavitation suppression strip is greater than or equal to the maximum span of the cavitation zone of the blade.

7. The anti-cavitation impeller according to any one of claims 1 to 6, wherein:

on the suction surface, along the direction in which the leading edge points to the trailing edge, the height of the downstream cavitation suppressing strip is higher than the height of the upstream cavitation suppressing strip.

8. The anti-cavitation impeller according to any one of claims 1 to 7, wherein:

the length direction is arranged along an extending direction of a leading edge line of the leading edge.

9. The anti-cavitation impeller according to any one of claims 1 to 8, wherein:

the surface of the cavitation inhibition strip is of a continuous smooth curved surface structure.

10. The utility model provides an axial-flow pump, includes the pipeline and installs impeller in the pipeline which characterized in that:

the impeller is an anti-cavitation impeller as claimed in any one of claims 1 to 9.

Technical Field

The invention relates to the technical field of pumps, in particular to an anti-cavitation impeller and an axial flow pump constructed by the anti-cavitation impeller.

Background

The axial flow pump is widely applied to industrial production as a large-flow low-lift pump, mechanical energy is converted into fluid energy through rotation of an impeller, and in the operation process of the axial flow pump, due to reduction of environmental pressure or insufficient design allowance, cavitation often occurs on the impeller of the axial flow pump, so that the lift and the efficiency of the pump are reduced, and problems of vibration, noise, cavitation and the like are caused.

In order to control cavitation or relieve damage caused by cavitation, the main measures adopted at present are impeller inlet optimization, blade load optimization, inducer addition, inlet injection pressurization, double-suction structure and the like, so that the flow rate of a pump inlet is reduced and the pressure of the pump inlet is increased, and the cavitation is controlled or relieved. However, in these measures, the problems of complex structure and high cost exist in the additional arrangement of an inducer, the injection pressurization at the inlet and the adoption of a double-suction structure, and the cavitation control effect is very limited; the measures such as impeller inlet optimization, blade load optimization and the like have the advantages that on one hand, the cavitation control effect is limited, and on the other hand, the efficiency of the pump is reduced to a large extent; in addition, the above measures have the problem of narrow applicable working condition, and are difficult to play a good cavitation control effect under variable working conditions.

In order to solve the above technical problems, patent document No. CN204610363U discloses an axial flow pump for suppressing the cloud-like cavitation on the back surface of a blade, which adopts a technical scheme that a protruding barrier strip is arranged on the back surface of an impeller blade at a position 0.75C away from the water inlet edge of the blade, wherein C is the airfoil chord length of the blade to block the propagation process of the back jet flow on the wall surface of the blade, thereby suppressing the conversion from the sheet-like cavitation to the cloud-like cavitation. Although the raised barrier strips are provided and the cloud cavitation is controlled based on the mechanism of blocking back jet, the cavitation phenomenon existing at the front edge of the blade cannot be treated, so that the damage of noise and the like caused by vibration at the front edge of the blade under the unsteady characteristic is caused.

Disclosure of Invention

The invention mainly aims to provide an anti-cavitation impeller for an axial flow pump, which is used for inhibiting the front edge cavitation of a blade, so that the damage of vibration, noise, cavitation and the like caused by the front edge cavitation of the pump blade is effectively reduced;

it is another object of the present invention to provide an axial flow pump constructed with the above anti-cavitation impeller.

In order to achieve the main object, the axial flow pump impeller provided by the invention comprises a hub and blades fixed on the hub; the front half part of the suction surface of the blade is provided with more than one cavitation inhibiting strip which is arranged at intervals along the direction from the front edge of the blade to the tail edge of the blade, and the cavitation inhibiting strip is a strip-shaped convex structure which is arranged along the length direction along the spanwise direction.

Cavitation suppression strips which are arranged in an extending mode in the spanwise direction are arranged on the front half portion of the suction surface of the axial flow pump blade, so that the pressure on the blade surface on the front side of each suppression strip is increased to suppress the occurrence of front edge cavitation of the suction surface of the blade, and the damage of vibration, noise, cavitation and the like caused by the front edge cavitation is effectively reduced; further, since cavitation on the blade as a whole is generated at the leading edge region at the earliest and inertially progresses to the trailing edge, by providing the leading edge cavitation suppression strip, cavitation can be suppressed as a whole by suppressing cavitation in the leading edge region, so that the influence of the cavitation on efficiency and the like can be reduced.

The specific scheme is that more than two cavitation suppression strips are distributed on the suction surface and are arranged at intervals along the direction from the front edge of the blade to the tail edge of the blade. By providing two or more cavitation suppressing strips, cavitation induced by the cavitation suppressing strips on the upstream side of the downstream side cavitation suppressing strip can be utilized.

The preferable scheme is that more than one cavitation suppression strip arranged at intervals along the direction is fixedly arranged at the rear half part of the suction surface adjacent to the tail edge along the direction that the front edge points to the tail edge. To suppress cavitation as a whole and improve the efficiency of the impeller.

More preferably, in the front half part of the blade, the cavitation inhibition strip is arranged in the range of 0.2C to 0.4C away from the front edge; in the back half part, the cavitation inhibition strips are arranged in the range of the area which is 0.5C to 0.7C away from the front edge; wherein C is the blade chord length from the leading edge to the trailing edge. The cavitation suppression strips are arranged in the area within the range of the front half part and the rear half part, so that the cavitation can be effectively suppressed, and the negative effects of hydraulic loss and the like caused by the arrangement of the cavitation suppression strips can be reduced.

Another preferred solution is that the cavitation suppressing strip spans the cavitation zone of the blade at its fixing position in the span direction of the blade.

More preferably, the length of the cavitation suppressing strips in the span direction is equal to or greater than the maximum span of the cavitation zone of the blade. Further, it is ensured that the cavitation can be effectively suppressed.

Another preferred solution is that the height of the projections of the downstream cavitation suppressing strips is higher than the height of the projections of the upstream cavitation suppressing strips on the suction surface in the direction from the leading edge toward the trailing edge. On the blade, as the cavitation length is longer, the thickness of the blade is increased, particularly after the front side cavitation inhibition strip is introduced, the cavitation is effectively inhibited by utilizing the subsequently increased bulge height, and meanwhile, the negative effects of hydraulic loss and the like caused by the addition of the front side inhibition strip are reduced.

Another preferred solution is that the length direction is arranged in the direction of extension of the leading edge line of the leading edge.

Still another preferred scheme is that the surface of the cavitation suppressing strip is a continuous smooth curved surface structure. Reduce the negative effects such as hydraulic loss brought by the addition of the inhibition strip.

In order to achieve the above another object, the present invention provides an axial flow pump including a pipe and an impeller installed in the pipe, wherein the impeller is the impeller described in any one of the above technical solutions.

Drawings

FIG. 1 is an axial cross-sectional schematic view of a partial structure of an embodiment of an axial flow pump according to the present invention;

FIG. 2 is an enlarged view of a portion A of FIG. 1;

FIG. 3 is a partial schematic view of the rim portion of the structure of FIG. 2;

FIG. 4 is a schematic view of a vane and rotating drive shaft configuration in an embodiment of an axial flow pump according to the present invention;

FIG. 5 is a front view of the structure shown in FIG. 4;

FIG. 6 is a partial block diagram of the structure shown in FIG. 5;

FIG. 7 is a photograph of a cavitation test of an impeller without a cavitation suppression strip added, under a condition of a cavitation number of 3.5;

FIG. 8 is a photograph of a cavitation test of an embodiment of an impeller of the present invention at a cavitation number of 3.5;

FIG. 9 is a photograph of a cavitation test of an impeller without the addition of a cavitation suppressing strip under a condition of a cavitation number of 2.5;

FIG. 10 is a photograph of a cavitation test conducted under a condition that a cavitation number of an impeller of an embodiment of the present invention is 2.5.

Detailed Description

The invention is further illustrated by the following examples and figures.

The invention mainly aims at improving the blade structure of the axial flow pump so as to improve the damage of vibration and the like caused by front edge cavitation under the unsteady characteristic, and designs the structures of parts such as pipelines, static guide vanes and the like in the axial flow pump by referring to the existing products.