Low-vibration blade structure and centrifugal or turbomachinery applying the same

Abstract

The low-vibration blade structure and the centrifugal or turbine fluid machine using the same are provided.The volute damping structure comprises a volute damping radial rectangular ring, a volute inner wall inflow side flow guide ring and a volute inner wall outflow side flow guide ring.The axial section of the volute damping radial rectangular ring is in a rectangular shape.The axial sections of the volute inner wall inflow side flow guide ring and the volute inner wall outflow side flow guide ring are both in a 1 / 4 circular structure, wherein the axial section radius of the volute inner wall inflow side flow guide ring is R2, the axial section radius of the volute inner wall outflow side flow guide ring is R3, and R2>R3.A blade damping groove is arranged on the blade, and the axial section of the blade damping groove is in a circular structure with a radius of R1, and 2R2

Description

Technical Field

[0001] This invention relates to the field of fluid machinery technology, specifically to a blade structure, and more specifically to a centrifugal or turbine fluid machinery using the same. Background Technology

[0002] Compressors, pumps, fans, and turbines are all common working components in the field of fluid machinery, playing a vital role in production and daily life. For example, centrifugal compressors typically achieve high gas pressure. Centrifugal compressors are usually bladed rotating machines. Their operation involves gas entering the impeller and, under the action of the impeller blades, rotating at high speed with the impeller while flowing towards the impeller outlet under the centrifugal force. The gas is then diffused by the impeller, increasing both its pressure and kinetic energy. Subsequently, within the diffuser channel, this kinetic energy is converted into static pressure energy, further increasing the gas pressure. Turbines convert high-enthalpy gas flow from upstream into low-enthalpy gas flow, converting the gas's internal energy into kinetic energy. This kinetic energy drives the impeller shaft, outputting mechanical energy. The main flow components include the volute, nozzles, impeller, and diffuser. After entering the volute, the high-temperature, high-pressure gas flows into the nozzles, impeller, and diffuser, finally exiting the turbine as a low-temperature, low-pressure gas, outputting work.

[0003] Blades are commonly used transformer components in compressors, pumps, fans, and turbines. By designing the blade structure, the safe operation of the unit can be ensured and the operating efficiency of the unit can be improved. Therefore, it is very necessary to optimize the design of blades.

[0004] Prior art CN105317737A discloses an impeller assembly and a centrifugal compressor having the same. The impeller assembly 100 includes: a rotating shaft 1, an impeller 2, and a pressure plate 3. The impeller 2 is a centrifugal impeller, and the centrifugal impeller can be an open centrifugal impeller or a closed centrifugal impeller. The impeller assembly 100 further includes: a threaded fastener 4, which (e.g., a screw) passes through the pressure plate 3 and engages with the rotating shaft 1.

[0005] Prior art CN1034983A discloses a turbine blade with an arbitrary conical surface shape, wherein the blade surface is shaped as an arbitrary conical surface that is not a circular conical surface. The arbitrary conical surface that is not a circular conical surface is formed by connecting points on any suitable curve (directrix) of the cone vertex and non-circular shape. The blade surface is a part of the arbitrary conical surface that is not a circular conical surface.

[0006] However, the aforementioned blades have design limitations, only involving the installation or airfoil design of the blades, without fundamentally changing the blade structure. They are not adaptable, have poor pressure variation capacity, large flow losses, poor performance under varying operating conditions, and low efficiency. Therefore, in order to address these problems, the applicant proposes a low-vibration blade structure and centrifugal or turbine fluid machinery that applies it to solve the above-mentioned problems and improve operating performance and efficiency. Summary of the Invention

[0007] The purpose of this invention is to address the shortcomings of existing technologies by proposing a low-vibration blade structure and centrifugal or turbine fluid machinery that utilizes it.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A low-vibration blade structure includes a hub, blades, an impeller back cover plate, and a volute. The blades are uniformly mounted on the hub to form an impeller, which is located within the enclosed space formed by the impeller back cover plate and the volute. The volute is characterized by having a vibration damping structure on its inner wall side, located at the midpoint of the blade's axial length near the outlet side. The vibration damping structure includes a radial rectangular ring, an inlet-side guide ring on the inner wall, and an outlet-side guide ring on the inner wall. The axial cross-section of the radial rectangular ring is rectangular, and the radial mid-section M of the radial rectangular ring is... An angle A exists between the impeller and the radial section N, where 5°≤A≤12°; the axial sections of both the inlet-side guide ring and the outlet-side guide ring on the inner wall of the volute are 1 / 4 circular structures, with the radius of the axial section circle of the inlet-side guide ring being R2 and the radius of the axial section circle of the outlet-side guide ring being R3, where R2>R3; blade vibration damping grooves are provided on the blades, with the axial section of the blade vibration damping grooves being circular structures and having a radius of R1, where 2R2<R1≤3R2; the radial rectangular ring of the volute extends into the blade vibration damping groove to form a low-vibration damping structure for the flow path.

[0010] Furthermore, a hub back guide vane is provided on the back of the hub, and the hub back guide vane has a three-dimensional curved and twisted guide vane structure.

[0011] Furthermore, there is a gap d between the hub back guide vane and the impeller rear cover plate, where d = (3.2~10.5) mm.

[0012] Furthermore, the inlet guide ring, the vibration damping radial rectangular ring, and the outlet guide ring on the inner wall of the volute are distributed along the airflow direction on the inner wall of the volute, and there are gaps between the inlet guide ring and the vibration damping radial rectangular ring, and between the vibration damping radial rectangular ring and the outlet guide ring.

[0013] Furthermore, the inlet guide ring, the vibration damping radial rectangular ring, and the outlet guide ring on the inner wall of the volute are installed adjacent to each other along the airflow direction on the inner wall of the volute and are fixed into an integral structure by laser welding.

[0014] Furthermore, the radial rectangular ring of the volute is uniformly provided with rectangular ring pressure stabilizing holes along the circumference.

[0015] Furthermore, the radius of the rectangular ring voltage stabilizing hole is R4, where R4 = (0.1~0.2)R2 + (0.25~0.33)R3.

[0016] Furthermore, a central blade is provided on the pressure surface of the blade. The central blade is located on the middle arc line of the pressure surface and is a three-dimensional curved blade.

[0017] Furthermore, the inlet end of the middle blade is provided with a blade inlet leaflet composed of two straight blades, the included angle of the two straight blades being B, 10°≤B≤30°.

[0018] Furthermore, the outlet end of the middle blade is provided with a blade outlet leaflet composed of two twisted blades, the included angle of the two twisted blades being C, 45°≤C≤60°.

[0019] A centrifugal compressor, characterized in that the centrifugal compressor includes the aforementioned low-vibration blade structure.

[0020] A turbine machine, characterized in that the turbine machine includes a generator, a left turbine machine, and a right turbine machine; the left turbine machine and the right turbine machine are respectively disposed on the left and right sides of the generator; both the left turbine machine and the right turbine machine have a hub, blades, an impeller back cover plate, and a volute; the turbine machine includes the aforementioned low-vibration blade structure.

[0021] This invention discloses a low-vibration blade structure and a centrifugal or turbine fluid machinery using the same. A volute vibration damping structure is provided on the inner wall side of the volute casing, located at the midpoint of the blade's axial length near the outlet side. The volute vibration damping structure includes a radially rectangular ring for vibration damping, an inlet-side guide ring on the inner wall of the volute casing, and an outlet-side guide ring on the inner wall of the volute casing. The axial cross-section of the radially rectangular ring for vibration damping is rectangular, and the radial mid-section M of the radially rectangular ring for vibration damping forms an angle A with the radial cross-section N of the impeller, where 5° ≤ A ≤ 1. 2°; The axial cross-sections of both the inlet-side and outlet-side guide rings on the inner wall of the volute are 1 / 4 circular structures, with the radius of the axial cross-section of the inlet-side guide ring being R2 and the radius of the axial cross-section of the outlet-side guide ring being R3, where R2 > R3; Blade damping grooves are provided on the blades, with an axial cross-section of circular structure and a radius of R1, where 2R2 < R1 ≤ 3R2; The radial rectangular ring of the volute extends into the blade damping grooves to form a low-vibration damping structure for the flow path. Due to improvements in the blade structure and the centrifugal or turbine fluid machinery using it, problems such as poor adaptability, poor pressure variation capacity, large flow losses, poor performance under varying operating conditions, and low efficiency have been solved, thus improving operating performance and efficiency. Attached Figure Description

[0022] Figure 1 A schematic diagram of the structure of centrifugal or turbine fluid machinery in the prior art;

[0023] Figure 2 A schematic diagram of the axial cross-section of the volute vibration damping structure for centrifugal or turbine fluid machinery;

[0024] Figure 3 A schematic diagram of the specific structure of the volute vibration reduction structure for centrifugal or turbine fluid machinery;

[0025] Figure 4 A schematic diagram of the axial section of an auxiliary structure for vibration damping of the volute of centrifugal or turbine fluid machinery.

[0026] In the diagram: 1. Hub; 2. Blade; 3. Impeller rear cover plate; 4. Middle blade; 5. Hub back guide vane; d. Spacing d between hub back guide vane 5 and impeller rear cover plate 3; 6. Volute; 7. Volute vibration damping structure; 71. Volute vibration damping radial rectangular ring; 72. Inlet guide ring on the inner wall of the volute; 73. Outlet guide ring on the inner wall of the volute; 74. Radial mid-section M of the volute vibration damping radial rectangular ring 71; 75. Radial section N of the impeller; 76. Radial mid-section M of the volute vibration damping radial rectangular ring 71 and radial section of the impeller. Angle A of N, axial cross-sectional radius R2 of the inlet guide ring 72 on the inner wall of the volute, axial cross-sectional radius R3 of the outlet guide ring 73 on the inner wall of the volute, blade damping groove 8, axial cross-sectional radius R1 of the blade damping groove 8, blade inlet leaflet 9, angle B of the two straight blades of the blade inlet leaflet 9, blade outlet leaflet 10, angle C of the two bent and twisted blades of the blade outlet leaflet 10, rectangular ring pressure stabilizing hole 11, radius R4 of the rectangular ring pressure stabilizing hole 11. Detailed Implementation

[0027] 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 only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] The present invention will now be described in further detail with reference to the accompanying drawings.

[0029] like Figure 1-4As shown, a low-vibration blade structure includes a hub 1, blades 2, an impeller rear cover plate 3, and a volute 6. The blades 2 are uniformly mounted on the hub 1 to form an impeller, which is located within the enclosed space formed by the impeller rear cover plate 3 and the volute 6. The volute 6 is characterized by having a volute vibration damping structure 7 on its inner wall side, located at the middle of the axial length of the blades 2 near the outlet side. The volute vibration damping structure 7 includes a radial rectangular ring 71, an inlet-side guide ring 72 on the inner wall of the volute, and an outlet-side guide ring 73 on the inner wall of the volute. The axial cross-section of the radial rectangular ring 71 is rectangular. The radial mid-section M and the radial section N of the impeller form an angle A, where 5°≤A≤12°; the axial sections of the inlet-side guide ring 72 and the outlet-side guide ring 73 on the inner wall of the volute are both 1 / 4 circular structures, with the radius of the axial section circle of the inlet-side guide ring 72 being R2 and the radius of the axial section circle of the outlet-side guide ring 73 being R3, where R2>R3; a blade damping groove 8 is provided on the blade 2, and the axial section of the blade damping groove 8 is circular with a radius of R1, where 2R2<R1≤3R2; the radial rectangular ring 71 of the volute extends into the blade damping groove 8 to form a low-vibration damping structure for the flow path.

[0030] The shape and structure of the blades significantly affect aerodynamic efficiency. Gas enters the machine through the inlet passage, and the blade geometry causes the distribution of relative fluid velocity, affecting the flow pattern along the wall and ultimately impacting losses and efficiency due to vibration. The blades in this application differ from conventional blades in the prior art. The applicant's research revealed that significant vibration is easily caused near the blade's outlet end. To address this issue, the applicant optimized the design of the blade near the outlet by incorporating a volute vibration damping structure 7 on the inner wall of the volute 6. This volute vibration damping structure 7 is located in the middle of the blade 2's axial length, near the outlet side. The casing vibration damping structure 7 includes a volute vibration damping radial rectangular ring 71, a volute inner wall inlet-side guide ring 72, and a volute inner wall outlet-side guide ring 73. The axial cross-sections of the volute inner wall inlet-side guide ring 72 and the volute inner wall outlet-side guide ring 73 are both 1 / 4 circular structures. The blade 2 is provided with a blade vibration damping groove 8. The volute vibration damping radial rectangular ring 71 extends into the blade vibration damping groove 8 to form a low-vibration damping structure for the flow path. Through the optimized design of the above structure, it can solve the problems of poor adaptability, poor pressure variation capacity, large flow loss, poor performance under varying operating conditions, and low efficiency, thereby improving the operating performance and efficiency, and thus achieving high aerodynamic efficiency.

[0031] Furthermore, a hub back guide vane 5 is provided on the back of the hub, and the hub back guide vane 5 is a three-dimensional curved and twisted guide vane structure.

[0032] Furthermore, there is a gap d between the hub back guide vane 5 and the impeller rear cover plate 3, where d = (3.2~10.5) mm.

[0033] The hub back guide vane 5 plays a crucial role in improving the flow pattern, as it can help reduce vibration and stabilize the fluid flow.

[0034] Furthermore, the inlet guide ring 72, the vibration damping radial rectangular ring 71, and the outlet guide ring 73 on the inner wall of the volute are distributed along the airflow direction on the inner wall of the volute 6, and there are gaps between the inlet guide ring 72 and the vibration damping radial rectangular ring 71, and between the vibration damping radial rectangular ring 71 and the outlet guide ring 73.

[0035] Furthermore, the inlet guide ring 72, the vibration damping radial rectangular ring 71, and the outlet guide ring 73 on the inner wall of the volute are sequentially installed adjacent to each other along the airflow direction on the inner wall of the volute 6 and are fixed into an integral structure by laser welding.

[0036] Furthermore, the radial rectangular ring 71 of the volute is uniformly provided with rectangular ring pressure stabilizing holes 11 along the circumference.

[0037] Furthermore, the radius of the rectangular ring voltage stabilizing hole 11 is R4, R4 = (0.1~0.2)R2 + (0.25~0.33)R3.

[0038] The inlet-side guide ring 72, the vibration-damping radial rectangular ring 71, and the outlet-side guide ring 73 on the inner wall of the volute complement each other. Their arrangement reduces vibration at the outlet end. In particular, the above structure has a more significant impact on the fluid flow near the wall of the volute, reducing the wall's influence on the fluid and improving flow efficiency. The design of the rectangular ring pressure-stabilizing hole 11 also compensates for the pressure difference on both sides of the vibration-damping radial rectangular ring 71, further reducing instability and vibration caused by excessive pressure difference.

[0039] Furthermore, a middle blade 4 is provided on the pressure surface of blade 2. The middle blade 4 is located on the middle arc line of the pressure surface and is a three-dimensional curved blade.

[0040] Furthermore, the inlet end of the middle blade 4 is provided with a blade inlet leaflet 9 composed of two straight blades, the included angle of the two straight blades being B, 10°≤B≤30°.

[0041] Furthermore, the outlet end of the middle blade 4 is provided with a blade outlet leaflet 10 composed of two twisted blades, the included angle of the two twisted blades being C, 45°≤C≤60°.

[0042] The design of the aforementioned auxiliary blade structure can effectively adapt blade 2 and the flow channel to changes in flow, reduce separation in the flow, reduce energy loss, improve the overall performance of the machine, and reduce the possibility of rotational stall caused by airflow separation in the blade channel under changing operating conditions, thereby fundamentally reducing the occurrence of vibrations such as surge.

[0043] A centrifugal compressor, characterized in that the centrifugal compressor includes the aforementioned low-vibration blade structure.

[0044] A turbine machine, characterized in that the turbine machine includes a generator, a left turbine machine, and a right turbine machine; the left turbine machine and the right turbine machine are respectively disposed on the left and right sides of the generator; both the left turbine machine and the right turbine machine have a hub 1, blades 2, impeller back cover plate 3, and volute 6; the turbine machine includes the above-mentioned low-vibration blade structure.

[0045] This invention discloses a low-vibration blade structure and a centrifugal or turbine fluid machinery using the same. A volute vibration damping structure is provided on the inner wall side of the volute casing, located at the midpoint of the blade's axial length near the outlet side. The volute vibration damping structure includes a radially rectangular ring for vibration damping, an inlet-side guide ring on the inner wall of the volute casing, and an outlet-side guide ring on the inner wall of the volute casing. The axial cross-section of the radially rectangular ring for vibration damping is rectangular, and the radial mid-section M of the radially rectangular ring for vibration damping forms an angle A with the radial cross-section N of the impeller, where 5° ≤ A ≤ 1. 2°; The axial cross-sections of both the inlet-side and outlet-side guide rings on the inner wall of the volute are 1 / 4 circular structures, with the radius of the axial cross-section of the inlet-side guide ring being R2 and the radius of the axial cross-section of the outlet-side guide ring being R3, where R2 > R3; Blade damping grooves are provided on the blades, with an axial cross-section of circular structure and a radius of R1, where 2R2 < R1 ≤ 3R2; The radial rectangular ring of the volute extends into the blade damping grooves to form a low-vibration damping structure for the flow path. Due to improvements in the blade structure and the centrifugal or turbine fluid machinery using it, problems such as poor adaptability, poor pressure variation capacity, large flow losses, poor performance under varying operating conditions, and low efficiency have been solved, thus improving operating performance and efficiency.

Claims

1. A low-vibration blade structure, comprising a hub (1), blades (2), an impeller rear cover plate (3), and a volute (6); the blades (2) are uniformly mounted on the hub (1) to form an impeller, the impeller being located within the enclosed space formed by the impeller rear cover plate (3) and the volute (6); characterized in that: A volute vibration damping structure (7) is provided on the inner wall side of the volute (6). The volute vibration damping structure (7) is located in the middle of the axial length of the blade (2) near the outlet side. The volute vibration damping structure (7) includes a volute vibration damping radial rectangular ring (71), a volute inner wall inlet side guide ring (72), and a volute inner wall outlet side guide ring (73). The axial section of the volute vibration damping radial rectangular ring (71) is rectangular. The radial mid-section M of the volute vibration damping radial rectangular ring (71) and the radial section N of the impeller have an angle A, 5°≤A≤12°. The volute inner wall inlet side guide ring... The axial cross-sections of the ring (72) and the flow guide ring (73) on the outflow side of the volute inner wall are both 1 / 4 circular structures. The axial cross-sectional radius of the flow guide ring (72) on the inflow side of the volute inner wall is R2, and the axial cross-sectional radius of the flow guide ring (73) on the outflow side of the volute inner wall is R3, where R2 > R3. The blade (2) is provided with a blade damping groove (8). The axial cross-section of the blade damping groove (8) is circular, and its radius is R1, where 2R2 < R1 ≤ 3R2. The radial rectangular ring (71) of the volute damping extends into the blade damping groove (8) to form a low vibration damping structure for the flow path.

2. The low-vibration blade structure as described in claim 1, characterized in that, The back of the hub is provided with hub back guide vanes (5), which are three-dimensional curved and twisted guide vane structures.

3. The low-vibration blade structure as described in claim 1, characterized in that, There is a gap d between the hub back guide vane (5) and the impeller back cover plate (3), where d = (3.2~10.5) mm.

4. The low-vibration blade structure as described in claim 1, characterized in that, The inlet guide ring (72), the vibration damping radial rectangular ring (71), and the outlet guide ring (73) on the inner wall of the volute are distributed along the airflow direction on the inner wall of the volute (6), and there are gaps between the inlet guide ring (72) and the vibration damping radial rectangular ring (71), and between the vibration damping radial rectangular ring (71) and the outlet guide ring (73).

5. The low-vibration blade structure as described in claim 1, characterized in that, The inlet guide ring (72), the vibration damping radial rectangular ring (71), and the outlet guide ring (73) on the inner wall of the volute are installed sequentially and adjacently on the inner wall of the volute (6) along the airflow direction and are fixed into an integral structure by laser welding.

6. The low-vibration blade structure as described in claim 1, characterized in that, The volute vibration damping radial rectangular ring (71) is uniformly provided with rectangular ring pressure stabilizing holes (11) along the circumference.

7. A low-vibration blade structure as described in claim 6, characterized in that, The radius of the rectangular ring voltage stabilizing hole (11) is R4, R4 = (0.1~0.2)R2 + (0.25~0.33)R3.

8. The low-vibration blade structure as described in claim 1, characterized in that, A middle blade (4) is provided on the pressure surface of the blade (2). The middle blade (4) is located on the middle arc line of the pressure surface and is a three-dimensional curved blade.

9. A low-vibration blade structure as described in claim 8, characterized in that, The inlet end of the middle blade (4) is provided with a blade inlet leaflet (9) composed of two straight blades, the included angle of the two straight blades is B, 10°≤B≤30°.

10. A low-vibration blade structure as described in claim 8, characterized in that, The outlet end of the middle blade (4) is provided with a blade outlet leaflet (10) composed of two twisted blades, the included angle of the two twisted blades is C, 45°≤C≤60°.

11. A centrifugal compressor, characterized in that, The centrifugal compressor includes the low-vibration blade structure as described in any one of claims 1 to 10.

12. A turbomachinery, characterized in that, The turbine machinery includes a generator, a left turbine machinery, and a right turbine machinery; the left turbine machinery and the right turbine machinery are respectively arranged on the left and right sides of the generator; both the left turbine machinery and the right turbine machinery have a hub (1), blades (2), impeller back cover plate (3), and volute (6); the turbine machinery includes the low vibration blade structure according to any one of claims 1 to 10.

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