A compressor blade and impeller

Abstract

The application relates to the technical field of compressors, in particular to a compressor blade and impeller, which comprises integrally-formed first and second blade surfaces, the first blade surface is arranged along a vertical direction, the bottom end of the first blade surface is connected with the top end of the second blade surface, and a preset included angle is formed between the second blade surface and the first blade surface, so that the second blade surface is curved towards the suction side of the blade; and the leading edge of the second blade surface is swept forward to the flow direction. According to the application, the leakage vortex at the gap between the blade and the hub can be weakened, the blockage can be reduced, and the pressure expansion capacity of the blade can be improved.

Description

Technical Field

[0001] This invention relates to the field of compressor technology, and in particular to a compressor blade and impeller. Background Technology

[0002] In some gas turbines, a gap is created between the compressor blade root and the hub. Near this gap, the high static pressure gradient on both sides of the blade induces strong leakage flow in the rotor gap region. This strong leakage flow interferes with the suction surface boundary layer of the blade and shears against the mainstream fluid, inducing a large low-speed region at the compressor blade root, accompanied by strong leakage vortices and large low-speed fluid masses. This not only leads to significant aerodynamic losses but also severely blocks the airflow passage and exacerbates compressor rotational stall, seriously affecting the stability of compressor operation.

[0003] Therefore, there is an urgent need for a compressor blade and impeller to solve the above problems. Summary of the Invention

[0004] This invention provides a compressor blade and impeller that can reduce leakage vortices at the gap between the blade and the hub, reduce blockage, and improve the blade's diffusion capacity.

[0005] In a first aspect, embodiments of the present invention provide a compressor blade, comprising: an integrally formed first blade surface and a second blade surface, wherein the first blade surface is arranged in a vertical direction, the bottom end of the first blade surface is connected to the top end of the second blade surface, and the second blade surface and the first blade surface form a preset angle, so that the second blade surface bends towards the suction side of the blade.

[0006] The leading edge of the second blade sweeps forward in the direction of the incoming flow.

[0007] In one possible design, the vertical distance d1 from the intersection of the midsection axis of the first blade and the midsection axis of the second blade to the bottom of the second blade ranges as follows:

[0008] 5g < d1 < 0.2h;

[0009] In the formula, g is the clearance height between the bottom end of the second blade and the hub of the compressor; h is the distance between the top end of the first blade and the bottom end of the second blade.

[0010] In one possible design, the preset angle is the angle between the midsection axis of the first blade and the midsection axis of the second blade.

[0011] In one possible design, the preset included angle ranges from 0 to 45°.

[0012] In one possible design, the leading edge of the second blade sweeps forward in the direction of the incoming flow in a triangular shape.

[0013] In one possible design, the perpendicular distance from the intersection of the extension of the hypotenuse of the triangle towards the trailing edge of the second blade and the extension of the leading edge towards the hub to the bottom of the second blade is equal to the perpendicular distance from the intersection of the midsection axis of the first blade and the midsection axis of the second blade to the bottom of the second blade.

[0014] In one possible design, the angle between the hypotenuse of the triangle and the bottom of the second leaf surface ranges from 0 to 45°.

[0015] In one possible design, the cross-sectional shapes of both the first and second blade surfaces are such that they first increase in size and then decrease in size from the leading edge to the trailing edge.

[0016] Secondly, embodiments of the present invention provide a compressor impeller, comprising: a hub and a plurality of blades in any of the above designs;

[0017] The multiple blades are evenly arranged along the circumference of the hub.

[0018] In this embodiment of the invention, by bending the second blade towards the suction side of the blade and sweeping the leading edge of the second blade towards the incoming flow direction, the load distribution at the blade root can be altered, reducing and shifting the maximum load forward, increasing the leading edge load, and decreasing the load in the middle. On one hand, the forward shift of the maximum load and the increase in the leading edge load can shift the starting point of the leakage vortex entering the flow field forward. On the other hand, the reduction in the maximum load reduces the vortex core intensity of the leakage vortex, and the leakage vortex is affected by the load in the middle as it develops downstream, thereby reducing the load in the middle of the blade and weakening the leakage flow. Therefore, the compressor blade provided in this application can weaken the leakage vortex at the gap between the blade and the hub, reduce blockage, and improve the blade's diffusion capacity, thereby improving the compressor's pressure ratio and efficiency. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of a prior art blade provided in an embodiment of the present invention;

[0021] Figure 2This is an axial view of a compressor blade at a certain angle provided in an embodiment of the present invention;

[0022] Figure 3 This is an axial view of a compressor blade from another angle, according to an embodiment of the present invention;

[0023] Figure 4 This is a side view of a compressor blade provided in an embodiment of the present invention;

[0024] Figure 5 This is a front view of a compressor blade provided in an embodiment of the present invention;

[0025] Figure 6 This is a schematic diagram of leakage vortices generated by blades in existing technology;

[0026] Figure 7 This is a schematic diagram of the leakage vortex generated by the blades provided in this application.

[0027] Figure label:

[0028] 1-Leaf;

[0029] 11-First leaf surface; 12-Second leaf surface;

[0030] 2-Wheel hub. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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 some embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0032] like Figure 1 The diagram shows a schematic of a compressor blade provided by existing technology. As can be seen, the blade is positioned perpendicular to the radial direction, with a constant cross-sectional area. This type of blade generates strong leakage vortices near the gap between the blade tip and the hub, resulting not only in aerodynamic losses but also severe blockage of the airflow passage and exacerbating compressor rotational stall.

[0033] For the reasons mentioned above, the inventors improved the air compressor blade profile.

[0034] like Figures 2-5As shown, in a first aspect, an embodiment of the present invention provides a compressor blade, including: an integrally formed first blade surface 11 and a second blade surface 12, the first blade surface 11 is arranged in a vertical direction, the bottom end of the first blade surface 11 is connected to the top end of the second blade surface 12, and the second blade surface 12 and the first blade surface 11 form a preset angle, so that the second blade surface 12 bends toward the suction side of the blade 1.

[0035] The leading edge of the second blade 12 sweeps forward in the direction of the incoming flow.

[0036] In this embodiment, by bending the second blade 12 towards the suction side of the blade 1 and sweeping the leading edge of the second blade 12 forward in the direction of the incoming flow, the load distribution at the root of the blade 1 can be changed, reducing and shifting the maximum load forward, increasing the leading edge load, and reducing the load in the middle. On the one hand, the forward shift of the maximum load and the increase in the leading edge load can shift the starting point of the leakage vortex entering the flow field forward. On the other hand, the reduction in the maximum load reduces the vortex core intensity of the leakage vortex, and the leakage vortex is affected by the load in the middle as it develops downstream, thereby reducing the load in the middle of the blade 1 and weakening the leakage flow. Therefore, the compressor blade provided in this embodiment can weaken the leakage vortex at the gap between the blade 1 and the hub 2, reduce blockage, and improve the diffusion capacity of the blade 1, thereby improving the compressor's pressure ratio and efficiency.

[0037] like Figure 4 As shown, in some embodiments, the vertical distance d1 from the intersection of the mid-section axis of the first blade 11 and the mid-section axis of the second blade 12 to the bottom end of the second blade 12 ranges as follows:

[0038] 5g < d1 < 0.2h;

[0039] In the formula, g is the clearance height between the bottom end of the second blade 12 and the hub 2 of the compressor; h is the distance between the top end of the first blade 11 and the bottom end of the second blade 12.

[0040] Furthermore, the preset included angle is the angle between the mid-section axis of the first blade surface 11 and the mid-section axis of the second blade surface 12. The value of this preset included angle α ranges from 0 to 45°, preferably from 20 to 30°.

[0041] like Figure 5 As shown, in some embodiments, the shape of the portion of the leading edge of the second blade 12 that sweeps forward in the direction of the incoming flow is triangular.

[0042] In some embodiments, the vertical distance from the intersection of the extension of the hypotenuse of the triangle toward the trailing edge of the second blade 12 and the extension of the leading edge toward the hub 2 to the bottom of the second blade 12 is equal to the vertical distance from the intersection of the mid-section axis of the first blade 11 and the mid-section axis of the second blade 12 to the bottom of the second blade 12.

[0043] Furthermore, the angle β between the hypotenuse of the triangle and the bottom of the second leaf surface 12 ranges from 0 to 45°, preferably from 20 to 30°.

[0044] In some embodiments, the cross-sectional shapes of the first blade 11 and the second blade 12 are such that they first increase in size and then decrease in size from the leading edge to the trailing edge.

[0045] The above settings can effectively improve the load distribution at the root of blade 1, reduce the vortex core intensity of leakage vortices, reduce blockage and improve the diffusion capacity of the blades, thereby improving the compressor's pressure ratio and efficiency.

[0046] To demonstrate the effectiveness of the blade of this invention in reducing leakage vortices, the inventors conducted simulation tests on blades of the prior art and the blade of this application. The test results are as follows: Figure 6 and Figure 7 As shown. Among them, Figure 6 To address the leakage vortex generated by the blades using existing technology. Figure 7 The leakage vortex generated by the blades in this application is shown in the figure. Figure 7 The vortex core strength of the leakage vortex is significantly smaller than that of the vortex core in the middle. Figure 6 The vortex core intensity in the vortex is thus reduced. Therefore, the compressor blade provided in this application can effectively improve the load distribution at the blade root, reduce the vortex core intensity of the leakage vortex, reduce blockage, and improve the blade's diffusion capacity, thereby increasing the compressor's pressure ratio and efficiency.

[0047] Secondly, embodiments of the present invention also provide a compressor impeller, including a hub 2 and a plurality of blades 1 provided in any of the above embodiments;

[0048] The multiple blades 1 are evenly arranged along the circumference of the hub 2.

[0049] It should be noted that the compressor impeller provided in this embodiment has the same technical effect as the compressor blade provided in the previous embodiment, and the technical effects of each implementation in this embodiment will not be described in detail here.

[0050] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A compressor blade, characterized in that, include: The first blade (11) and the second blade (12) are integrally formed. The first blade (11) is arranged in a vertical direction. The bottom end of the first blade (11) is connected to the top end of the second blade (12). The second blade (12) and the first blade (11) form a preset angle so that the second blade (12) bends toward the suction side of the blade (1). The leading edge of the second blade (12) sweeps forward in the direction of the incoming flow; The range of values ​​for the vertical distance d1 from the intersection of the midsection axis of the first blade (11) and the midsection axis of the second blade (12) to the bottom of the second blade (12) is as follows: 5g < d1 < 0.2h; In the formula, g is the clearance height between the bottom end of the second blade (12) and the hub (2) of the compressor; h is the distance between the top end of the first blade (11) and the bottom end of the second blade (12); The leading edge of the second blade (12) sweeps forward in the direction of the incoming flow in a triangular shape; The perpendicular distance from the intersection of the extension of the hypotenuse of the triangle toward the trailing edge of the second blade (12) and the extension of the leading edge toward the hub (2) to the bottom of the second blade (12) is equal to the perpendicular distance from the intersection of the mid-section axis of the first blade (11) and the mid-section axis of the second blade (12) to the bottom of the second blade (12). The angle between the hypotenuse of the triangle and the bottom of the second leaf surface (12) is in the range of 20~30°.

2. The compressor blade according to claim 1, characterized in that, The preset angle is the angle between the mid-section axis of the first blade (11) and the mid-section axis of the second blade (12).

3. The compressor blade according to claim 2, characterized in that, The preset included angle ranges from 0 to 45°.

4. The compressor blade according to any one of claims 1-3, characterized in that, The cross-sectional shapes of the first leaf surface (11) and the second leaf surface (12) are both: the shape increases first and then decreases from the leading edge to the trailing edge.

5. An impeller for a compressor, characterized in that, Includes a hub (2) and a plurality of blades (1) as described in any one of claims 1-4; Multiple blades (1) are evenly arranged around the circumference of the hub (2).

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