Low-vibration blade structure and centrifugal or turbine fluid machine applying same

Abstract

The invention discloses a low-vibration blade structure and a centrifugal or turbine fluid machine applying the low-vibration blade structure. A volute vibration reduction structure comprises a volute vibration reduction radial rectangular ring, a volute inner wall face inflow side flow guide ring and a volute inner wall face outflow side flow guide ring. The axial section of the volute damping radial rectangular ring is rectangular; the axial section of the volute inner wall face inflow side flow guide ring and the axial section of the volute inner wall face outflow side flow guide ring are each of a 1 / 4 circle structure, the circle radius of the axial section of the volute inner wall face inflow side flow guide ring is R2, the circle radius of the axial section of the volute inner wall face outflow side flow guide ring is R3, and R2 is larger than R3. Blade vibration reduction grooves are formed in the blades, the axial section of each blade vibration reduction groove is of a circular structure, the radius of each blade vibration reduction groove is R1, and R1 is larger than 2R2 and smaller than or equal to 3R2. Due to the fact that the blade structure and the centrifugal or turbine fluid machine applying the blade structure are improved, the problems of poor adaptability, poor pressure transformation capacity, large flow loss, poor variable working condition performance, low efficiency and the like are solved, and the working condition performance and the operation efficiency are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of fluid machinery, in particular to a blade structure, and more particularly to a centrifugal or turbine fluid machinery using the blade structure. Background Art

[0002] Compressors, pumps, fans, turbines, etc. are all common working parts in the field of fluid machinery, which are of great significance to production and life. For example, centrifugal compressors can usually make the gas obtain a higher pressure. Centrifugal compressors are usually blade-type rotating machinery. The working mode of centrifugal compressors is usually that after the gas enters the impeller of the centrifugal compressor, under the action of the impeller blades, it rotates at high speed with the impeller, and flows to the impeller outlet under the action of the rotating centrifugal force, and is subjected to the expansion effect of the impeller, so that the pressure energy and kinetic energy of the gas are increased. Subsequently, in the expansion flow channel, this part of the kinetic energy is converted into static pressure energy, thereby further increasing the gas pressure. The turbine converts the high-enthalpy airflow from the upstream into a low-enthalpy airflow, converts the internal energy of the gas into kinetic energy, and thus drives the impeller's rotating shaft to output the kinetic energy into mechanical energy. Its main flow components include volute, nozzle, impeller and diffuser. After the high-temperature and high-pressure airflow enters the volute, it flows into the nozzle, impeller and diffuser, and finally the low-temperature and low-pressure airflow leaves the turbine and outputs work.

[0003] Blades are commonly used transformer components in compressors, pumps, fans, and turbines. The design of the blade structure can ensure the safe operation of the unit and improve the unit's operating efficiency. It can be seen that it is very necessary to optimize the design of the blades.

[0004] Prior art CN105317737A discloses an impeller assembly and a centrifugal compressor having the same, the impeller assembly 100 comprising: a rotating shaft 1, an impeller 2 and a pressing 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 comprises: a threaded fastener 4, the threaded fastener 4 (such as a screw) passes through the pressing plate 3 and then cooperates with the rotating shaft 1.

[0005] Prior art CN1034983A discloses a turbine fan sheet blade shaped with an arbitrary conical surface, wherein the blade surface is shaped with an arbitrary conical surface of a non-conical surface. The arbitrary conical surface of the non-conical surface is formed by connecting the points on any appropriate curve (directrix) of the non-circular surface and the cone vertex. The blade surface is a part of the arbitrary conical surface of the non-conical surface.

[0006] However, the above-mentioned blades have design limitations, which only involve the installation of the blades or the blade shape design, and do not fundamentally change the blade structure. They have weak adaptability, poor pressure conversion capability, large flow losses, poor variable operating performance, and low efficiency. Therefore, in response to these problems, the applicant proposes a low-vibration blade structure and a centrifugal or turbine fluid machinery using the same to solve the above-mentioned problems and improve operating performance and efficiency. Summary of the invention

[0007] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a low-vibration blade structure and a centrifugal or turbine fluid machinery using the same.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] A low-vibration blade structure, comprising a hub, blades, an impeller rear cover plate, and a volute; the blades are evenly mounted on the hub to form an impeller, and the impeller is located in an enclosed space formed by the impeller rear cover plate and the volute; the characteristics are: a volute vibration reduction structure is arranged on the inner wall surface side of the volute, and the volute vibration reduction structure is located in the middle of the axial length of the blade close to the outlet side; the volute vibration reduction structure comprises a volute vibration reduction radial rectangular ring, a guide ring on the inlet side of the volute inner wall surface, and a guide ring on the outlet side of the volute inner wall surface; the axial section of the volute vibration reduction radial rectangular ring is rectangular, and the radial middle section M of the volute vibration reduction radial rectangular ring is There is an angle A with the radial section N of the impeller, 5°≤A≤12°; the axial sections of the guide ring on the inlet side of the volute inner wall and the guide ring on the outlet side of the volute inner wall are both 1 / 4 circle structures, wherein the axial section circle radius of the guide ring on the inlet side of the volute inner wall is R2, and the axial section circle radius of the guide ring on the outlet side of the volute inner wall is R3, wherein R2>R3; a blade vibration damping groove is arranged on the blade, and the axial section of the blade vibration damping groove is a circular structure, and its radius is R1, 2R2<R1≤3R2; the volute vibration damping radial rectangular ring extends into the blade vibration damping groove to form a flow path low vibration damping structure.

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

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

[0012] Furthermore, the guide ring on the inlet side of the inner wall of the volute, the radial rectangular ring of the volute vibration reduction, and the guide ring on the outflow side of the inner wall of the volute are distributed on the inner wall of the volute along the airflow direction, and there is a gap between the guide ring on the inlet side of the inner wall of the volute and the radial rectangular ring of the volute vibration reduction, and between the radial rectangular ring of the volute vibration reduction and the guide ring on the outflow side of the inner wall of the volute.

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

[0014] Furthermore, the volute vibration-damping radial rectangular ring is evenly provided with rectangular ring pressure-stabilizing holes along the circumferential direction.

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

[0016] Furthermore, a middle blade is arranged on the pressure surface of the blade. The middle blade is located on the median arc line of the pressure surface, and the middle blade is a three-dimensional twisted blade.

[0017] Furthermore, a blade inlet leaflet consisting of two straight plate-shaped blades is provided at the inlet end of the middle blade, and the included angle between the two straight plate-shaped blades is B, and 10°≤B≤30°.

[0018] Furthermore, a blade outlet leaflet consisting of two bent and twisted blades is provided at the outlet end of the middle blade, and the included angle between the two bent and twisted blades is C, 45°≤C≤60°.

[0019] A centrifugal compressor is characterized in that it comprises the above-mentioned 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 arranged on the left and right sides of the generator; the left turbine machine and the right turbine machine are both equipped with a hub, blades, an impeller rear cover plate, and a volute; the turbine machine includes the above-mentioned low-vibration blade structure.

[0021] The invention discloses a low-vibration blade structure and a centrifugal or turbine fluid machinery using the same. The inner wall surface of the volute is provided with a volute vibration-damping structure, which is located in the middle of the axial length of the blade and close to the outlet side. The volute vibration-damping structure comprises a volute vibration-damping radial rectangular ring, a guide ring on the inlet side of the volute inner wall surface, and a guide ring on the outlet side of the volute inner wall surface. The axial cross section of the volute vibration-damping radial rectangular ring is rectangular, and an angle A is formed between the radial middle cross section M of the volute vibration-damping radial rectangular ring and the radial cross section N of the impeller, and the angle A is 5°≤A≤1 2°; the axial cross-sections of the guide ring on the inlet side of the volute inner wall and the guide ring on the outlet side of the volute inner wall are both 1 / 4 circular structures, wherein the axial cross-section circle radius of the guide ring on the inlet side of the volute inner wall is R2, and the axial cross-section circle radius of the guide ring on the outlet side of the volute inner wall is R3, wherein R2>R3; blade vibration reduction grooves are arranged on the blades, and the axial cross-section of the blade vibration reduction grooves is a circular structure, and its radius is R1, 2R2<R1≤3R2; the radial rectangular ring of the volute vibration reduction extends into the blade vibration reduction groove to form a low-vibration vibration reduction structure of the flow path. Due to the improvement of the blade structure and the centrifugal or turbine fluid machinery using it, the problems of poor adaptability, poor pressure conversion capacity, large flow loss, poor variable operating performance, low efficiency, etc. are solved, and the operating performance and operation efficiency are improved. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0023] Figure 2 It is a schematic axial cross-sectional view of a volute vibration reduction structure of a centrifugal or turbine fluid machinery;

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

[0025] Figure 4 The present invention is a schematic axial cross-sectional view of an auxiliary structure of a volute vibration damping structure of a centrifugal or turbine fluid machinery.

[0026] In the figure: hub 1, blades 2, impeller rear cover 3, middle blades 4, hub back guide vanes 5, distance d between hub back guide vanes 5 and impeller rear cover 3, volute 6, volute vibration reduction structure 7, volute vibration reduction radial rectangular ring 71, volute inner wall inlet side guide ring 72, volute inner wall outlet side guide ring 73, radial middle section M of volute vibration reduction radial rectangular ring 71, radial section N of impeller, radial middle section M of volute vibration reduction radial rectangular ring 71 and radial section of impeller N, the angle A of the axial cross-section circle radius R2 of the guide ring 72 on the inlet side of the inner wall of the volute, the axial cross-section circle radius R3 of the guide ring 73 on the outlet side of the inner wall of the volute, the blade vibration damping groove 8, the axial cross-section radius R1 of the blade vibration damping groove 8, the blade inlet leaflet 9, the angle B of the two straight plate-shaped blades of the blade inlet leaflet 9, the blade outlet leaflet 10, the angle C of the two twisted blades of the blade outlet leaflet 10, the rectangular ring pressure stabilizing hole 11, and the radius R4 of the rectangular ring pressure stabilizing hole 11. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] The present invention will be further described in detail below in conjunction with the accompanying drawings.

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

[0030] The shape and structure of the blades significantly affect the aerodynamic efficiency of the air. The gas enters the machine through the inlet passage. The geometric characteristics of the blades will cause the distribution of the relative velocity of the fluid, which will affect the distribution of the flow state along the wall and ultimately affect the loss and efficiency caused by vibration. The blades in this application are different from the conventional blades in the prior art. After research, the applicant found that the position near the outlet end of the blade is very likely to cause obvious vibration. In response to the above problem, the applicant optimized the design of the blades near the outlet part, and the inner wall surface side of the volute 6 is provided with a volute vibration reduction structure 7, and the volute vibration reduction structure 7 is located in the middle of the axial length of the blade 2 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 circle structures; blade vibration damping grooves 8 are arranged on the blades 2; the volute vibration damping radial rectangular ring 71 extends into the blade vibration damping groove 8 to form a flow path low vibration damping structure. Through the optimized design of the above structure, it can solve the problems of poor adaptability, poor pressure transformation capability, large flow loss, poor variable operating performance, low efficiency, etc., improve the operating performance and operation efficiency, and thus obtain 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 bent and twisted guide vane structure.

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

[0033] The hub back guide vane 5 plays a vital role in improving the flow pattern, and can assist in reducing vibration and stabilizing the fluid flow pattern.

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

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

[0036] Furthermore, the volute vibration-damping radial rectangular ring 71 is evenly provided with rectangular ring pressure-stabilizing holes 11 along the circumferential direction.

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

[0038] The guide ring 72 on the inlet side of the volute inner wall, the radial rectangular ring 71 of the volute vibration reduction, and the guide ring 73 on the outlet side of the volute inner wall complement each other, and the arrangement of their structures reduces the vibration of the outlet end part, especially the above structure has a more significant effect on the flow state of the fluid near the wall of the volute 6, reducing the influence of the wall on the fluid and improving the flow efficiency. The design of the rectangular ring pressure stabilizing hole 11 also compensates for the pressure difference on the two sides of the radial rectangular ring 71 of the volute vibration reduction, further reducing the instability and vibration caused by excessive pressure difference.

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

[0040] Furthermore, a blade inlet leaflet 9 consisting of two straight plate-shaped blades is provided at the inlet end of the middle blade 4, and the included angle between the two straight plate-shaped blades is B, and 10°≤B≤30°.

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

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

[0043] A centrifugal compressor is characterized in that it comprises the above-mentioned 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 arranged on the left and right sides of the generator; the left turbine machine and the right turbine machine are both equipped with a hub 1, blades 2, an impeller rear cover plate 3, and a volute 6; the turbine machine includes the above-mentioned low-vibration blade structure.

[0045] The invention discloses a low-vibration blade structure and a centrifugal or turbine fluid machinery using the same. The inner wall surface of the volute is provided with a volute vibration-damping structure, which is located in the middle of the axial length of the blade and close to the outlet side. The volute vibration-damping structure comprises a volute vibration-damping radial rectangular ring, a guide ring on the inlet side of the volute inner wall surface, and a guide ring on the outlet side of the volute inner wall surface. The axial cross section of the volute vibration-damping radial rectangular ring is rectangular, and an angle A is formed between the radial middle cross section M of the volute vibration-damping radial rectangular ring and the radial cross section N of the impeller, and the angle A is 5°≤A≤1 2°; the axial cross-sections of the guide ring on the inlet side of the volute inner wall and the guide ring on the outlet side of the volute inner wall are both 1 / 4 circular structures, wherein the axial cross-section circle radius of the guide ring on the inlet side of the volute inner wall is R2, and the axial cross-section circle radius of the guide ring on the outlet side of the volute inner wall is R3, wherein R2>R3; blade vibration reduction grooves are arranged on the blades, and the axial cross-section of the blade vibration reduction grooves is a circular structure, and its radius is R1, 2R2<R1≤3R2; the radial rectangular ring of the volute vibration reduction extends into the blade vibration reduction groove to form a low-vibration vibration reduction structure of the flow path. Due to the improvement of the blade structure and the centrifugal or turbine fluid machinery using it, the problems of poor adaptability, poor pressure conversion capacity, large flow loss, poor variable operating performance, low efficiency, etc. are solved, and the operating performance and operation efficiency are improved.

Claims

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

2. A low vibration blade structure according to claim 1, characterized in that: A hub back guide vane (5) is arranged on the back of the hub, and the hub back guide vane (5) is a three-dimensional bent and twisted guide vane structure.

3. A low vibration blade structure as claimed in claim 1, characterized in that: There is a distance d between the hub back guide vane (5) and the impeller rear cover plate (3), wherein d=(3.2-10.5) mm.

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

5. A low vibration blade structure as claimed in claim 1, characterized in that: The guide ring (72) on the inlet side of the volute inner wall, the volute vibration reduction radial rectangular ring (71), and the guide ring (73) on the outlet side of the volute inner wall are installed adjacent to each other in sequence on the volute (6) inner wall along the airflow direction and fixed into an integrated structure by laser welding.

6. A low vibration blade structure as claimed in claim 1, characterized in that: The volute vibration-damping radial rectangular ring (71) is evenly provided with rectangular ring pressure-stabilizing holes (11) along the circumferential direction.

7. A low vibration blade structure according to claim 6, characterized in that: The radius of the rectangular ring pressure-stabilizing hole (11) is R4, where R4=(0.1-0.2)R2+(0.25-0.33)R3.

8. A low vibration blade structure as claimed in claim 1, characterized in that: A middle blade (4) is arranged on the pressure surface of the blade (2). The middle blade (4) is located on the mid-arc line of the pressure surface. The middle blade (4) is a three-dimensional twisted blade.

9. A low vibration blade structure as claimed 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 plate-shaped blades, and the included angle between the two straight plate-shaped blades is B, 10°≤B≤30°.

10. A low vibration blade structure according to 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, and 45°≤C≤60°.

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

12. A turbomachinery, characterized in that: The turbine machinery comprises 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; the left turbine machinery and the right turbine machinery are both equipped with a hub (1), blades (2), an impeller rear cover plate (3), and a volute (6); the turbine machinery comprises the low-vibration blade structure described in any one of claims 1 to 10.

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