An arc-shaped line-based water pump blade structure and a method for weakening the harm of cavitation to blades

Abstract

The application relates to a water pump blade structure based on arc-shaped lines and a method for weakening the harm of cavitation to blades, which comprises water pump blades installed on a hub, and the blades and the hub jointly form an impeller; the hub diameter is d, starting from 0.35d of the hub from the pressure surface of the water pump blade, rectangular grids are evenly divided on the surface of the water pump blade; arc-shaped lines are arranged in the rectangular grids, the corresponding circular arc diameter of the arc-shaped cross section of the arc-shaped lines is 0.2d, the corresponding circular arc diameter of the arc-shaped lines on the water pump blade plane is 0.6d, and the corresponding circular arc diameter of the central axis profile of the arc-shaped lines is 0.7d; the arc-shaped lines are irregularly arranged on the blades in a staggered mode along the radial direction of the impeller; the arc-shaped lines are curved to the side where the water flows out of the blades; after the arc-shaped lines are arranged, the blade surface forms irregular concaves and protrusions arranged along the radial direction of the impeller. Through the application, the harm of cavitation to the blades can be weakened, vibration and noise can be reduced, and the strength and service life of the blades can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of water pump blade structure based on arc-shaped line and its method for weakening the harm of cavitation to blade, belong to water conservancy engineering, municipal engineering technical field. BACKGROUND

[0002] When water pump blade works, its high-speed rotation can form low pressure area on blade suction surface, when impeller speed is larger, the pressure value of low pressure area is lower than water vaporization pressure, so that a large number of cavitation bubbles are generated in water body.When cavitation bubble flows into blade pressure surface along with water flow, due to the sudden increase of pressure, cavitation bubble is broken.When cavitation bubble is broken and attached to blade, the shock wave generated can erode and damage blade, damage blade structure in long-term operation, reduce blade strength and working efficiency.In addition, cavitation can also cause blade vibration, excessive noise and other problems in operation.It is an important factor affecting the safe and stable operation of water pump.In actual operation, the faster the impeller speed or the water pump is not in the high efficiency area, the more cavitation phenomenon is prone to occur, and mainly concentrated on blade pressure surface.At present, the main methods to improve the cavitation resistance of blade are to select high-strength materials to manufacture blade or to cover special coating on the surface of blade.Selecting high-strength materials to manufacture blade can increase the manufacturing cost and processing difficulty of blade, and still produce cavitation damage in different degrees in long-term operation.While using coating method needs regular inspection and maintenance of coating, and the operation and management is difficult.Currently, the existing patents do not make great changes to the structure of water pump blade, and there is no effective solution to cavitation. SUMMARY

[0003] The purpose of the present application is to solve the problems of the prior art, and to provide a water pump blade structure based on arc-shaped line and its method for weakening the harm of cavitation to blade, which can effectively weaken the harm of cavitation to water pump blade, improve the service life of blade, and improve the efficiency and practicality of water pump.

[0004] In order to achieve the above-mentioned purpose of the application, the technical scheme adopted by the present application is as follows: a water pump blade structure based on arc-shaped line, comprising water pump blades installed on a hub, and the blades are installed on the hub to form an impeller; characterized in that: the diameter of the hub is d, and starting from 0.35d away from the hub on the pressure surface of the water pump blade, rectangular grids are evenly divided on the surface of the water pump blade.

[0005] An arc-shaped line is arranged in the rectangular grid, the arc-shaped cross section of the arc-shaped line corresponds to a circular arc diameter of 0.2d, the corresponding circular arc diameter of the arc-shaped line on the plane of the water pump blade is 0.6d, and the corresponding circular arc diameter of the central axis of the arc-shaped line is 0.7d.

[0006] The arc-shaped lines are arranged in a staggered and irregular manner along the radial direction of the impeller on the blade; the arc-shaped lines are curved towards the side where water flows out of the blade.

[0007] After setting the arc-shaped lines, the blade surface forms the concave pits and convex projections arranged in disorder along the radial direction of the impeller.

[0008] The width of the rectangular grid is 0.06d, and the length is 0.08d.

[0009] The method for weakening the harm of cavitation to the blade by using an arc-shaped line-based water pump blade structure is provided, after setting the arc-shaped lines, the water pump blade surface forms the concave pits and convex projections arranged in disorder along the radial direction of the impeller, the generated cavitation bubbles are not easy to adhere to the blade; for a few cavitation bubbles adhering to the blade, the adhesion points will be concentrated in the convex part; when the cavitation bubbles adhering to the blade surface and close to the blade surface break, the shock wave energy generated will be dissipated by the surface arc-shaped lines, thereby weakening the harm of cavitation to the blade, reducing vibration and noise, and improving the strength and service life of the blade.

[0010] The method is advanced in science, and through the method, an arc-shaped line blade structure is provided: taking a hub diameter as d, a rectangular grid is uniformly divided on the blade surface from 0.35d away from the hub on the pressure surface of the blade, the width of the grid is 0.06d, and the length is 0.08d. Arc-shaped lines are arranged in the rectangular grid, the problem of water flow disorder in the flow passage is solved, the diameter of the corresponding arc-shaped cross section is 0.2d. The diameter of the corresponding arc in the line on the blade plane is 0.6d. The diameter of the corresponding arc in the line on the central axis section is 0.7d. The lines are arranged in a staggered and irregular manner along the radial direction of the impeller on the blade. The lines are curved towards the side from which water flows out of the blade.

[0011] Beneficial effects: after the lines are arranged, the blade surface forms the concave pits and convex projections arranged in disorder along the radial direction of the impeller, and the generated cavitation bubbles are not easy to adhere to the blade. For a few cavitation bubbles adhering to the blade, the adhesion points will be concentrated in the convex part. When the cavitation bubbles adhering to the blade surface and close to the blade surface break, the shock wave energy generated will be dissipated by the surface lines, thereby weakening the harm of cavitation to the blade, reducing vibration and noise, and improving the strength and service life of the blade. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 is the blade surface grid division diagram in the application;

[0013] Figure 2 is the line plane bending diagram in the application;

[0014] Figure 3 is the line cross section in the application;

[0015] Figure 4 is the central axis section arc surface in the application;

[0016] Figure 5It is a surface texture schematic diagram in the application. DETAILED DESCRIPTION

[0017] The application is further described below in combination with the drawings and the description of the drawings.

[0018] A water pump blade structure based on arc-shaped texture, comprising water pump blades installed on a hub, the blades being installed on the hub to jointly form an impeller; the hub diameter is d, and starting from 0.35d away from the hub on the pressure surface of the water pump blade, rectangular grids are evenly divided on the surface of the water pump blade (such as Figure 1 );

[0019] An arc-shaped texture is arranged in the rectangular grid, the arc-shaped cross section of the arc-shaped texture corresponds to a circular arc diameter of 0.2d (such as Figure 3 ), the circular arc diameter corresponding to the arc-shaped texture on the water pump blade plane is 0.6d (such as Figure 2 ), and the circular arc diameter corresponding to the central axis of the arc-shaped texture is 0.7d (such as Figure 4 );

[0020] The arc-shaped texture is irregularly arranged on the blades in a staggered manner along the radial direction of the impeller; the arc-shaped texture is curved towards the side from which the water flows out of the blade;

[0021] After the arc-shaped texture is arranged, the surface of the blade forms irregular concaves and protrusions arranged in the radial direction of the impeller.

[0022] The width of the rectangular grid is 0.06d, and the length is 0.08d.

[0023] In use, after the arc-shaped texture is arranged, the surface of the water pump blade forms irregular concaves and protrusions arranged in the radial direction of the impeller, and the cavitation bubbles generated are not easy to adhere to the blade; for a small number of cavitation bubbles adhering to the blade, the adhesion points will be concentrated on the protruding part; when the cavitation bubbles adhering to the blade surface and close to the blade surface break, the shock wave energy generated will be dissipated by the surface arc-shaped texture, thereby reducing the damage of cavitation to the blade, reducing vibration and noise, and improving the strength and service life of the blade.

[0024] In blade manufacturing, corresponding size cutters are used for cutting processing by numerical control machine tools.

Claims

1. A pump blade structure based on arc-shaped texture, comprising pump blades mounted on a hub, the blades together forming an impeller; characterized in that: The hub diameter is d. Starting from 0.35d away from the hub from the pressure surface of the pump blade, a rectangular grid is evenly divided on the surface of the pump blade. The rectangular grid has arc-shaped patterns. The arc diameter corresponding to the arc cross-section of the arc pattern is 0.2d, the arc diameter corresponding to the arc pattern on the pump blade plane is 0.6d, and the arc diameter corresponding to the arc pattern on the central axis section is 0.7d. The arc-shaped patterns are arranged irregularly and interlaced along the radial direction of the impeller on the blades; the arc-shaped patterns bend toward the side where the water flows out of the blades; After the arc-shaped pattern is set, the blade surface forms disordered pits and protrusions arranged radially along the impeller.

2. The pump blade structure based on arc-shaped texture according to claim 1, characterized in that: The rectangular grid has a width of 0.06d and a length of 0.08d.

3. A method for mitigating cavitation damage to pump blades using a pump blade structure based on arc-shaped texture as described in claim 1 or 2, characterized in that: After the arc-shaped pattern is set, the surface of the water pump blade forms disordered pits and protrusions arranged radially along the impeller, making it difficult for the generated cavitation bubbles to adhere to the blade; for the few cavitation bubbles that do adhere to the blade, their attachment points will be concentrated on the protruding parts. When cavitation bubbles attached to or close to the blade surface burst, the resulting shock wave energy is dissipated by the surface's arc-shaped texture, thereby reducing the damage of cavitation to the blade, decreasing vibration and noise, and improving blade strength and service life.

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