WO2017028319A1

WO2017028319A1 - Centrifugal compressor and impeller thereof

Info

Publication number: WO2017028319A1
Application number: PCT/CN2015/087712
Authority: WO
Inventors: 王志强; 黄子彬
Original assignee: 深圳智慧能源技术有限公司
Priority date: 2015-08-20
Filing date: 2015-08-20
Publication date: 2017-02-23

Abstract

A centrifugal compressor (10) comprises a centrifugal impeller (12) and a pressure expander (14). The centrifugal impeller (12) comprises a hub (18) capable of rotating around an axis and comprises a plurality of blades (20). The hub (18) is provided with an arc-shaped flow passage surface (22). The plurality of blades (20) is disposed on the arc-shaped flow passage surface (22). Each blade (20) extends from a flow passage inlet (24) of the hub (18) to a flow passage outlet (26) of the hub (18). The pressure expander (14) surrounds the flow passage outlet (26) of the hub (18). An annular flange (28) is disposed on the flow passage outlet (26) of the hub (18). The annular flange (28) protrudes out of tips of the blades (20) in the radial direction, and is provided with a flange surface (30) in smooth connection with the flow passage surface (22). The pressure expander (14) is provided with a flat surface (36) perpendicular to the axis. The flat surface (36) is flush with a radial outermost side (38) on the flange surface (30). The centrifugal compressor can protect blades and simplify the mounting and the positioning.

Description

Centrifugal compressor and its impeller

Technical field

The present invention relates to a centrifugal compressor, and more particularly to an impeller of a centrifugal compressor.

Background technique

Centrifugal compressors include an impeller, a diffuser, and a wheel cover. The impeller generally includes a hub and a plurality of vanes disposed on the hub, the wheel shroud being positioned axially relative to the impeller. The tip of the blade is generally flush with the annular edge of the outlet end of the hub. During handling, if it collides with other components, it is highly likely to damage the blades. Moreover, during operation, the edge of the impeller may collide with other components, such as diffusers, due to vibration or bearing failure, etc., and may also cause blade damage. Therefore, in order to prevent the above-mentioned collision due to some abnormal reasons during the operation, the prior art forms a large gap between the diffuser and the impeller, ensuring that even if the above abnormality occurs, the collision does not occur, so that This protects the blades. The larger gap between the diffuser and the impeller utilizes other structural designs for the transition.

Another problem is the lack of calibration points when these components are installed. The positional relationship of the impeller, diffuser and wheel cover in the axial direction is critical to the performance of the compressor. However, the tip of the blade is flush with the annular edge of the hub, and there is no location on the hub that can serve as a calibration point. Therefore, it is difficult to accurately position the impeller, the diffuser and the wheel cover.

technical problem

In view of this, this paper proposes a centrifugal compressor capable of protecting the blade and simplifying the mounting position.

An impeller of a centrifugal compressor capable of protecting the blade and simplifying the mounting position is also proposed.

Technical solution

An impeller of a centrifugal compressor as set forth herein includes a hub rotatable about an axis and a plurality of blades, the hub having an arcuate flow passage surface, the plurality of vanes being disposed on the curved flow passage surface, each A blade extends from the runner inlet of the hub to the runner outlet of the hub. The hub is provided with an annular flange at the flow passage outlet, the annular flange protruding radially beyond the tip of the blade.

In an embodiment, the surface of the annular flange is smoothly connected to the arcuate flow passage surface.

The centrifugal compressor proposed in this paper includes a centrifugal impeller and a diffuser. The centrifugal impeller includes a hub rotatable about an axis and a plurality of blades, the hub having an arcuate flow passage surface, the plurality of vanes being disposed on the curved flow passage surface, each vane being from the hub The runner inlet extends to the runner outlet of the hub. The diffuser surrounds a flow passage outlet of the hub. The hub is provided at its flow passage outlet with an annular flange that protrudes radially beyond the tip of the blade, the annular flange having a smooth connection with the flow passage surface A flange surface, the diffuser having a flat surface perpendicular to the axis, the flat surface of the diffuser being flush with a radially outermost edge of the flange surface.

In an embodiment, the centrifugal compressor includes a wheel cover that covers the plurality of blades and forms an axial gap with the plurality of blades.

In an embodiment, the diffuser includes a plurality of diffuser vanes disposed on a flat surface of the diffuser, the wheel shroud being in contact with the diffuser vanes.

Beneficial effect

In summary, the hub of the impeller is provided at the runner outlet with an annular flange that projects radially beyond the tip of the blade. Even in exceptional situations, it is most likely that the flange collides with other components, rather than the blade colliding with other components. The presence of the annular flange thus provides protection to the blade. Moreover, due to the presence of the annular flange, the radial spacing between the diffuser and the impeller can be reduced, which facilitates improved aerodynamic performance. After the gap is reduced, there is no need to pass other structural designs to make the transition between the impeller and the diffuser. In addition, the radially outermost edge of the annular flange can be used as a mounting calibration point. After the diffuser is accurately positioned, the wheel cover is directly pushed into contact with the diffuser vanes of the diffuser to achieve precise positioning of the wheel cover, and thus the present invention This makes it possible to simplify the positioning of the compressor.

DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic cross-sectional view showing a partial structure of an embodiment of a centrifugal compressor.

Figure 2 is an enlarged view of the annular flange portion of Figure 1.

Figure 3 is a perspective view of an embodiment of an impeller.

Embodiments of the invention

Before the embodiments are described in detail, it is understood that the invention is not limited to the details The invention may be embodied in other ways. Also, it will be understood that the phraseology and terminology used herein are for the purpose of description The words "including", "comprising", "having", and <RTIgt; </ RTI> <RTIgt; </ RTI> used herein are meant to include the items listed thereafter, their equivalents, and other additional items. In particular, when describing "a certain element", the invention does not limit the number of the elements to one, and may include a plurality.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a cross-sectional view showing a portion of a configuration of a centrifugal compressor, Fig. 2 is an enlarged view of a portion of the annular flange of Fig. 1, and Fig. 3 is a perspective view showing an embodiment of the impeller.

As shown in FIGS. 1 through 3, the centrifugal compressor 10 includes a centrifugal impeller 12, a diffuser 14, and a wheel house 16. The centrifugal impeller 12 includes a hub 18 rotatable about an axis and a plurality of vanes 20 coupled to the hub 18. The hub 18 has an arcuate flow passage surface 22. The plurality of vanes 20 are disposed on the curved flow passage surface 22, wherein the vanes 20, the hub 18 and the wheel house 16 collectively form a flow passage of the hub 18. Each vane 20 extends from the runner inlet 24 of the hub 18 to the runner outlet 26 of the hub 18.

The hub 18 defines an annular flange 28 at the runner exit 26. The annular flange 28 projects radially beyond the tip of the blade 20. The annular flange 28 has a flange surface 30 that is smoothly coupled to the hub flow passage surface 22. Since the hub 18 is provided with an annular flange 28 outside the tip of the blade 20, even if it collides with other components, it is more likely that the flange 28 collides with other components, thereby reducing the collision of the blade 20 with other components. opportunity. Thus, the provision of the flange 28 provides protection to the blade under various abnormal conditions, such as shaft vibration, bearing failure, or inadvertent collision during handling.

The diffuser 14 utilizes the difference in cross-sectional area of the flow to convert the velocity of the compressed air into pressure energy. The diffuser 14 is a stationary member that includes an annular seat 32 and a plurality of diffuser vanes 34 disposed on the annular seat 32. The annular seat 32 surrounds the flow passage outlet 26 of the hub 18, and in particular, surrounds the annular flange 28 of the hub 18 and forms a radial spacing with the annular flange 28 to permit rotation of the impeller 12. In the prior art, in order to avoid collision under abnormal conditions, the radial spacing between the annular seat 32 and the annular flange 28 is set larger, and the larger clearance is designed by other structures to perform the impeller 12 and the pressure expansion. The transition between the devices 14. In the present embodiment, even in an abnormal situation, the flange 28 collides with other elements, such as the diffuser 14, instead of the blade 20 colliding with the diffuser 14. Thus, due to the presence of the annular flange 28, the radial spacing between the annular seat 32 and the annular flange 28 can be reduced, which facilitates improved aerodynamic performance. Moreover, after the gap is reduced, there is no need to perform a transition between the impeller 12 and the diffuser 14 by other structural design.

The annular seat 32 has a flat surface 36 on which the diffuser vanes 34 are disposed. Since the hub 18 has an annular flange 28 that projects radially beyond the blade tip, the radially outermost edge 38 of the flange surface of the annular flange 28 can serve as a calibration point for the axial position of the diffuser 14. In the prior art, since the blade extends to the annular edge of the hub, there is no suitable portion on the hub that is suitable for correction, and table correction cannot be performed. The radially outermost edge of the annular flange 28 in this embodiment provides a positioning reference when the diffuser 14 is installed.

The wheel cover 16 covers the flow path of the centrifugal impeller 12 and forms an axial gap with the blade 20. The axial clearance should be small enough not to leak, and large enough to ensure that the wheel 20 does not hit the wheel cover 16 when it is rotated. Therefore, a certain degree of installation accuracy must be ensured during installation. In the present embodiment, the wheel cover 16 is directly pushed into contact with the diffuser vanes 34 during installation, i.e., a precise axial gap between the wheel guard 16 and the vanes is ensured. As previously mentioned, the diffuser 14 utilizes the edge of the annular flange as a calibration point, thus ensuring precise positioning of the diffuser 14. When designing and installing, the apex of the diffuser vane is used as a reference point, which also ensures the installation accuracy of the wheel cover.

In summary, the present invention provides a centrifugal compressor and an impeller thereof that can provide protection to the blade. The hub of the impeller is provided at the runner outlet with an annular flange that projects radially beyond the tip of the blade. Even in exceptional situations, it is most likely that the flange collides with other components, rather than the blade colliding with other components. The presence of the annular flange thus provides protection to the blade. Moreover, due to the presence of the annular flange, the radial spacing between the diffuser and the impeller can be reduced, which facilitates improved aerodynamic performance. After the gap is reduced, there is no need to pass other structural designs to make the transition between the impeller and the diffuser. In addition, the radially outermost edge of the annular flange can be used as a mounting calibration point. After the diffuser is accurately positioned, the wheel cover is directly pushed into contact with the diffuser vanes of the diffuser to achieve precise positioning of the wheel cover, and thus the present invention This makes it possible to simplify the positioning of the compressor.

The concepts described herein may be embodied in other forms without departing from the spirit and scope. The specific embodiments disclosed are to be considered as illustrative and not restrictive. Therefore, the scope of the invention is to be determined by the appended claims Any changes which come within the meaning and range of the claims are intended to be within the scope of the claims.

Claims

An impeller of a centrifugal compressor includes a hub rotatable about an axis and a plurality of blades, the hub having an arcuate flow passage surface, the plurality of vanes being disposed on the curved flow passage surface, each vane from a runner inlet of the hub extends to a runner outlet of the hub, wherein the hub is provided with an annular flange at the runner outlet, the annular flange protruding radially from the blade Beyond the tip of the leaf.
The impeller of a centrifugal compressor according to claim 1, wherein a surface of said annular flange is smoothly connected to said curved flow passage surface.
A centrifugal compressor comprising a centrifugal impeller and a diffuser, the centrifugal impeller comprising a hub rotatable about an axis and a plurality of blades, the hub having an arcuate flow passage surface, the plurality of blades being disposed at the Said arcuate flow passage surface, each vane extending from a flow passage inlet of said hub to a flow passage outlet of said hub, said diffuser surrounding a flow passage outlet of said hub, characterized in that said hub An annular flange is provided at the outlet of the flow passage, the annular flange protruding radially beyond the tip of the blade, the annular flange having a flange surface that is smoothly connected to the flow passage surface The diffuser has a flat surface perpendicular to the axis, and a flat surface of the diffuser is flush with a radially outermost edge of the flange surface.
A centrifugal compressor according to claim 3, wherein said centrifugal compressor comprises a wheel cover covering said plurality of blades and forming an axial gap with said plurality of blades.
A centrifugal compressor according to claim 4, wherein said diffuser comprises a plurality of diffuser vanes disposed on said flat surface of said diffuser, said wheel shroud and said diffuser vane contact.