A wear-resistant runner blade edge reinforcing structure

Abstract

The utility model discloses an anti -wear runner blade edge reinforced structure, including runner body and blade, the blade is by the blade root, the front edge and the trailing edge is composed, the surface of trailing edge is provided with V -shaped groove, V -shaped groove adopts the way of equidistance, staggered distribution to set up in the surface of trailing edge, when the device is located in the sand -laden water flow or the sand -laden environment use, through the slope of V -shaped groove will particle impact force be decomposed into normal and tangential component, tangential force guides particle to slip along the slope, avoids direct impact blade body, this device sets up V -shaped groove on the surface of trailing edge, avoided traditional blade only from material hardness angle passively resist cavitation and wear, to the sand -laden water flow or the sand -laden environment in particle wear, smooth surface can only passively bear the vertical impact and cutting action of particle, and the wear rate is high, and the protection life is short and the blade needs frequent shutdown repair or replacement, and the maintenance cost is high, help to improve the service life of blade, save the cost.

Description

Technical Field

[0001] This utility model relates to the field of rotor blade technology, specifically to a wear-resistant rotor blade edge reinforcement structure. Background Technology

[0002] As the core energy conversion component of turbomachinery, turbine blades play a crucial role in the entire operation of the equipment. Their edge regions, specifically the leading and trailing edges, are subjected to extremely harsh working environments, continuously enduring the violent impact of high-speed fluids, severe abrasion from solid particles, and intense cavitation erosion caused by cavitation bubble collapse. The combined effect of these multiple factors makes the edge regions of turbine blades one of the most critical parts of the equipment most prone to failure. The performance of the blades, including their structural strength, wear resistance, and cavitation resistance, directly determines the operating efficiency, service life, and stability of the entire turbomachinery. In short, the quality of the turbine blades directly affects the overall performance and reliability of the turbomachinery.

[0003] Currently, most turbine blades are designed and manufactured with smooth edges or reinforced only through methods such as welding wear-resistant materials or thermal spraying hard coatings. However, this traditional smooth-edge design only passively resists cavitation erosion and wear from the perspective of material hardness. For cavitation erosion, smooth surfaces cannot suppress the initial formation of cavitation bubbles, nor can they change the location and energy of cavitation bubble collapse. The continuous impact of microjets on the surface leads to rapid coating failure and accelerated damage to the base material. For particle wear in sandy water flows or abrasive sand environments, smooth surfaces can only passively withstand the vertical impact and cutting action of particles, resulting in high wear rates and short protective lifespans. The blades require frequent shutdowns for repair or replacement, leading to high maintenance costs. Utility Model Content

[0004] The purpose of this invention is to provide a wear-resistant blade edge reinforcement structure to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a wear-resistant impeller blade edge reinforcement structure, comprising an impeller body and blades, wherein the blades are composed of a blade root, a leading edge and a trailing edge, and the surface of the trailing edge is provided with a V-shaped groove.

[0006] This device, by incorporating V-shaped grooves on the trailing edge surface, avoids the problem of traditional blades passively resisting cavitation and wear solely through material hardness. In sandy water flows or abrasive sand environments, smooth surfaces can only passively withstand the vertical impact and cutting action of particles, resulting in high wear rates and short protective lifespans. It also addresses the issues of frequent downtime for repair or replacement and high maintenance costs, thus helping to extend blade lifespan and save costs.

[0007] As a further preferred embodiment of this technical solution, the V-shaped grooves are arranged on the surface of the trailing edge in an equidistant and staggered manner.

[0008] The equidistant distribution ensures that the disturbance and control of the flow field are uniform throughout the target area. There are no areas of local "out-of-control" flow, nor are there new, unpredictable flow interactions caused by uneven spacing, thus achieving the design objectives stably and predictably.

[0009] Compared to parallel or aligned distributions, staggered distributions can achieve seamless coverage of the entire area with fewer trenches. This arrangement provides more continuous and efficient flow control within the same area, avoiding the "channeling" effect that may occur with parallel arrangements.

[0010] The staggered distribution avoids the formation of continuous "weak lines" in the V-shaped grooves perpendicular to the principal stress direction (usually the flow direction). It distributes stress more evenly throughout the matrix material, reducing the risk of the entire trailing edge being weakened across a single cross-section, thus helping to maintain overall structural stiffness and strength.

[0011] As a further preferred embodiment of this technical solution, the depth of the V-shaped groove is 50-100μm.

[0012] As a further preferred embodiment of this technical solution, the spacing between every two V-shaped grooves is 150 μm.

[0013] As a further preferred embodiment of this technical solution, the leading edge and the trailing edge naturally transition from thick to thin.

[0014] As a further preferred embodiment of this technical solution, a leaf root rounded corner is provided between the leaf root and the leading edge.

[0015] As a further preferred embodiment of this technical solution, a honeycomb sandwich structure is provided in the leading edge.

[0016] This utility model provides a wear-resistant impeller blade edge reinforcement structure, which has the following beneficial effects:

[0017] (1) By setting a V-shaped groove on the trailing edge surface, this utility model avoids the problem that traditional blades only passively resist cavitation and wear from the perspective of material hardness. For particle wear in sandy water flow or sandy environments, smooth surfaces can only passively bear the vertical impact and cutting action of particles, resulting in high wear rate and short protection life. The blades need to be frequently shut down for repair or replacement, and the maintenance cost is high. This invention helps to improve the service life of the blades and save costs.

[0018] (2) Compared with parallel and aligned distribution, the V-shaped grooves of this invention can achieve full coverage of the entire area with fewer grooves. This arrangement provides more continuous and efficient flow control within the same area and avoids the "channeling" effect that may exist in parallel arrangement. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0020] Figure 2 This is a side view of the overall structure of this utility model;

[0021] Figure 3 This is a schematic diagram of the blade structure of this utility model;

[0022] Figure 4 This is a schematic cross-sectional view of the blade structure of this utility model.

[0023] In the diagram: 1. Rotor body; 2. Blades;

[0024] 21. Leaf base; 22. Rounded corner of leaf base; 23. Leading edge; 24. Trailing edge;

[0025] 3. Honeycomb sandwich structure;

[0026] 4. V-shaped groove. Detailed Implementation

[0027] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.

[0028] This utility model provides a technical solution: such as Figures 1 to 4 As shown in this embodiment, a wear-resistant impeller blade edge reinforcement structure includes an impeller body 1 and a blade 2. The blade 2 is composed of a blade root 21, a leading edge 23 and a trailing edge 24. A V-shaped groove 4 is provided on the surface of the trailing edge 24.

[0029] When the device is used in a sandy water flow or sandy environment, the sand particles will impact the edge of the blade at high speed, which will cause "ploughing" and "cutting" wear. The wear rate of traditional straight-edge blades can reach 0.5 mm / year (actual measurement data of Yellow River turbine).

[0030] The inclined surface of the V-groove 4 decomposes the impact force of the particles into normal and tangential components. The normal force is reduced by 30%-40%, and the tangential force guides the particles to slide along the inclined surface, avoiding direct impact on the blade body.

[0031] Furthermore, the V-shaped groove 4 transforms wear from "local concentration" to "distribution along the groove," improving the uniformity of wear depth by 50%-60%.

[0032] In addition, the V-groove 4 can be combined with hard coatings (such as Stellite alloy) to form a "geometry + material" composite protection system.

[0033] This device, by setting V-shaped grooves 4 on the surface of the trailing edge 24, avoids the problem of traditional blades passively resisting cavitation and wear only from the perspective of material hardness. For particle wear in sandy water flow or sandy environments, smooth surfaces can only passively withstand the vertical impact and cutting action of particles, resulting in high wear rates and short protection lifespan. It also helps to improve the service life of blade 2 and save costs, addressing the problem of frequent downtime for repair or replacement of blade 2 and high maintenance costs.

[0034] Furthermore, a V-shaped groove 4 can also be set on the surface of the leading edge 23. Water flow is prone to separation at the leading edge of the blade due to the adverse pressure gradient, forming eddies and energy loss. The inclined surface of the V-shaped groove 4 smoothly guides the water flow to the blade surface, causing the flow separation point to move backward by 10%-15% (CFD simulation results).

[0035] For pump-turbines, the V-groove 4 design of the leading edge 23 can suppress the "suction vortex" phenomenon, thereby improving the unit's efficiency by 1.2%-1.5% under low load conditions.

[0036] like Figures 1 to 4 As shown, the V-shaped grooves 4 are arranged on the surface of the trailing edge 24 in an equidistant and staggered manner.

[0037] The equidistant distribution ensures that the disturbance and control of the flow field are uniform throughout the target area. There are no areas of local "out-of-control" flow, nor are there new, unpredictable flow interactions caused by uneven spacing, thus achieving the design objectives stably and predictably.

[0038] Compared to parallel or aligned distributions, staggered distributions can achieve seamless coverage of the entire area with fewer trenches. This arrangement provides more continuous and efficient flow control within the same area, avoiding the "channeling" effect that may occur with parallel arrangements.

[0039] The staggered distribution avoids the formation of continuous "weak lines" in the V-shaped grooves 4 perpendicular to the principal stress direction (usually the flow direction). It distributes stress more evenly in the matrix material, reducing the risk of the entire trailing edge 24 being weakened at a certain cross section, and helps maintain the overall structural stiffness and strength.

[0040] like Figures 1 to 4 As shown, the depth of the V-shaped groove 4 is 50-100μm.

[0041] In high-speed fluids (such as turbine impeller linear velocity >30m / s), excessively deep trenches (>100μm) are prone to forming local vortices at the bottom of the trench, which intensifies turbulent dissipation and leads to a 2% to 3% decrease in hydraulic efficiency.

[0042] During coating deposition, pore defects (porosity > 5%) are easily generated at the bottom of deep trenches, which reduces the coating bonding strength (bonding force < 30 MPa) and makes it easy to peel off under alternating stress.

[0043] Shallow trenches (<50μm) have limited buffering effect on sand particles, reducing the wear rate by only 10%–20%, which is insufficient for rivers with high sediment content (>3kg / m³). 3 (to meet the long-term operational needs of)

[0044] Under typical operating conditions of turbomachinery, the thickness of the laminar or viscous sublayer formed on the blade surface by fluid viscous forces is usually on the order of micrometers. Setting the depth of the V-groove 4 to 50-100 μm ensures that it is effectively embedded in this critical flow field region, rather than protruding ineffectively into the main fluid or being too shallow to have any effect.

[0045] like Figures 1 to 4 As shown, the spacing between every two V-shaped grooves 4 is 150 μm.

[0046] In sediment-laden water flows, the sand particles are mostly concentrated in the range of 50 to 200 μm. A spacing of 150 μm can ensure that most sand particles (about 70%) are captured by a single groove, thus avoiding the accumulation of sand particles and the formation of concentrated wear zones.

[0047] After sand particles impact the slope of the trench, the rebound angle increases by 15° to 20°, and the impact energy is dispersed to adjacent trenches, reducing the wear depth at a single point by more than 50% (experiments show that the wear rate drops from 2.1 mm / year to 0.7 mm / year).

[0048] The V-groove design with a spacing of 150 μm achieves a synergistic improvement in wear resistance, cavitation resistance, drag reduction, and self-cleaning performance through particle size matching, vortex size control, pressure gradient smoothing, and hydrophobic coating optimization. This parameter avoids the surge in processing costs caused by overly dense grooves (<100 μm) while overcoming the performance degradation problem of overly sparse grooves (>200 μm), providing key technical support for the long life and high-efficiency operation of the runner blades.

[0049] like Figures 1 to 4 As shown, the leading edge 23 and the trailing edge 24 transition naturally from thick to thin.

[0050] A thicker leading edge (typically 5%–8% of the chord length) can form a gradually narrowing flow channel, smoothing the fluid acceleration process and avoiding strong adverse pressure gradients caused by abrupt changes in cross-section. Experimental data show that when the leading edge thickness increases from 2 mm to 5 mm, the separation point shifts backward by 15%, and the hydraulic efficiency improves by 2.3%.

[0051] A trailing edge thinning (reducing the thickness to 0.5%–1% of the chord length) can reduce the intensity of wake turbulence and make the exit velocity distribution more uniform. CFD simulations show that when the trailing edge thickness is reduced from 2 mm to 0.8 mm, the integral scale of turbulence in the wake region decreases by 40%, and the total pressure loss decreases by 18%.

[0052] When a fluid flows over a curved surface, a boundary layer will form due to viscosity. If the surface changes too drastically (e.g., suddenly becomes thinner), the fluid in the boundary layer will stall due to the adverse pressure gradient, leading to flow separation.

[0053] A smooth transition can guide the fluid pressure to change smoothly, allowing the boundary layer to adhere tightly to the blade surface all the way to the trailing edge, greatly reducing the generation of eddies.

[0054] A naturally transitioning leading edge can create a more ideal pressure distribution: a thick leading edge creates a high-pressure zone, while a thin trailing edge creates a low-pressure zone, resulting in a gradual change in the pressure gradient and thus increasing the lift coefficient.

[0055] like Figures 1 to 4 As shown, a leaf root rounded corner 22 is provided between the leaf root 21 and the leading edge 23.

[0056] If the blade root 21 and the leading edge 23 are connected at a right angle, when the blade is under load (such as centrifugal force or fluid impact force), a stress peak will be generated at the right angle (the theoretical stress concentration factor can reach 3-5 times), which will become the initiation point of fatigue cracks.

[0057] By using the 22-rounded blade root transition geometry, stress can be evenly distributed along the curvature, reducing local stress peaks and decreasing the probability of microcrack initiation, while also inhibiting crack propagation.

[0058] A blade root fillet 22 is provided between the blade root 21 and the leading edge 23 for transition. Through stress concentration relief, flow separation suppression, fatigue life extension, and manufacturing process optimization, a multi-objective synergy of structural strength, fluid performance, and economy is achieved. This design avoids the excessive stress peak and increased flow loss caused by right-angle transitions, and overcomes the sensitivity of traditional sharp-corner designs to manufacturing defects, providing key technical support for the long-term stable operation of turbomachinery under extreme conditions.

[0059] like Figures 1 to 4 As shown, a honeycomb sandwich structure 3 is provided inside the leading edge 23.

[0060] The honeycomb sandwich structure 3 is a typical "sandwich structure" consisting of a high-strength upper panel, a lower panel, and a lightweight honeycomb core in the middle. Its mechanical principle is similar to that of an I-beam, distributing the material as far away from the neutral axis as possible, thereby achieving great bending stiffness with extremely light weight.

[0061] Honeycomb structures (such as aluminum honeycomb and Nomex honeycomb) have extremely high in-plane shear moduli (up to 10⁴–10¹⁰). 5 It has high compressive strength (5-20 MPa) and low density (approximately 0.1-0.5 g / cm³). 3 (only 1 / 5 to 1 / 10 the size of solid metal);

[0062] By adopting a honeycomb sandwich structure at the leading edge, the overall specific strength (strength / density) can be increased by 3 to 5 times, and the specific stiffness (stiffness / density) can be increased by 2 to 4 times. The honeycomb sandwich leading edge can reduce the weight of the blade by 15% to 20%, while the bending stiffness remains unchanged or is slightly improved.

[0063] The honeycomb sandwich structure 3 is specifically a lightweight ceramic honeycomb;

[0064] The ceramic panel provides tensile / compressive strength, while the honeycomb core material bears the shear load, forming a collaborative load-bearing mechanism of "panel-core-panel". Experiments show that the shear strength (50-100MPa) of the ceramic honeycomb sandwich structure is 2-3 times that of solid ceramics, and its impact resistance is significantly better than that of single-layer ceramic plates.

[0065] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A wear-resistant impeller blade edge reinforcement structure, comprising an impeller body (1) and blades (2), characterized in that: The blade (2) is composed of a leaf root (21), a leading edge (23) and a trailing edge (24), and the surface of the trailing edge (24) is provided with a V-shaped groove (4).

2. The wear-resistant impeller blade edge reinforcement structure according to claim 1, characterized in that: The V-shaped grooves (4) are arranged on the surface of the trailing edge (24) in an equidistant and staggered manner.

3. The wear-resistant impeller blade edge reinforcement structure according to claim 1, characterized in that: The depth of the V-shaped groove (4) is 50-100 μm.

4. The wear-resistant impeller blade edge reinforcement structure according to claim 1, characterized in that: The spacing between each pair of the V-shaped grooves (4) is 150 μm.

5. The wear-resistant impeller blade edge reinforcement structure according to claim 1, characterized in that: The leading edge (23) and trailing edge (24) transition naturally from thick to thin.

6. The wear-resistant impeller blade edge reinforcement structure according to claim 1, characterized in that: A leaf root rounded corner (22) is provided between the leaf root (21) and the leading edge (23).

7. The wear-resistant impeller blade edge reinforcement structure according to claim 1, characterized in that: A honeycomb sandwich structure (3) is provided inside the leading edge (23).

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