CN110878768A

CN110878768A - Vaned diffuser structure with variable inlet vane angle type guide vanes

Info

Publication number: CN110878768A
Application number: CN201911330317.0A
Authority: CN
Inventors: 何海龙; 佟鼎; 刘欣源; 高鹏浩; 刘畅; 丁占铭
Original assignee: China North Engine Research Institute Tianjin
Current assignee: China North Engine Research Institute Tianjin
Priority date: 2019-12-20
Filing date: 2019-12-20
Publication date: 2020-03-13

Abstract

The invention provides a vaned diffuser structure with variable inlet blade angle type guide vanes, which comprises an annular diffuser bottom plate and a plurality of variable inlet blade angle type guide vanes uniformly distributed on the annular diffuser bottom plate along the circumferential direction, wherein the vane channel rotating direction (from the inner diameter of the bottom plate to the outer diameter) of each variable inlet blade angle type guide vane is the same as the rotating direction of a compressor impeller, and the inlet blade angle of each variable inlet blade angle type guide vane is gradually increased along the vane height direction, namely the inlet blade angle β at the vane top is larger than the inlet blade angle α at the vane root.

Description

Vaned diffuser structure with variable inlet vane angle type guide vanes

Technical Field

The invention belongs to the technical field of exhaust gas turbocharging, and particularly relates to a vane diffuser structure with variable inlet vane angle type guide vanes.

Background

The pressure ratio of a gas compressor of the turbocharger is continuously improved due to the special requirement of continuously improving the power per liter and continuously reducing the displacement of the vehicle engine and recovering the power of the plateau environment engine. The pressure ratio of the single-stage compressor can reach more than 6 at present, which is attributed to the application of the vane diffuser.

The air flow compressed by the compressor to do work has higher flow velocity when flowing out of the impeller, and a part of kinetic energy can be subjected to speed reduction and diffusion in a subsequent diffusion device to be converted into pressure potential energy so as to further improve the pressure of the air flow. Diffuser devices are generally divided into vaneless diffusers and vaned diffusers. The vaneless diffuser has the characteristics of small diffusion degree, low efficiency, simple structure and wide flow range, so that the vaneless diffuser is widely applied to the automobile supercharger. The guide vane is added to the vane diffuser compared with a vane-free diffuser, larger diffusion pressure can be obtained under the same radial dimension, and in addition, the guide vane can enable the airflow at the outlet of the impeller to tend to be uniform and shorten the gas movement path, thereby improving the efficiency of the diffuser. However, the vaned diffuser has characteristics less gentle than that of the vaneless diffuser, and the flow rate range is narrow, which causes a problem of restricting the wide application thereof.

The flow loss of the vaned diffuser mainly includes friction loss, loss due to back pressure flow, separation loss, and the like. Due to the existence of the guide vane, the contact friction of high-speed airflow with the surface of the vane and the surface of the bottom plate is a main source of friction loss; too great a difference between the inlet flow angle and the inlet blade angle also results in greater separation and friction losses. How to effectively reduce the flow loss in the vaned diffuser is the key to improve the efficiency of the vaned diffuser, improve the flow characteristic and further improve the performance of the high-pressure-ratio turbocharger.

Disclosure of Invention

In view of the above, the present invention is directed to a vaned diffuser structure with variable inlet vane angle type guide vanes to optimize the performance of the conventional vaned diffuser and improve the efficiency and flow characteristics thereof.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

a vaned diffuser structure with variable inlet blade angle type guide vanes comprises an annular diffuser bottom plate and a plurality of variable inlet blade angle type guide vanes which are uniformly distributed on the annular diffuser bottom plate along the circumferential direction, wherein the vane channel turning direction (the inner diameter of the bottom plate points to the outer diameter) of the variable inlet blade angle type guide vanes is the same as the rotating turning direction of a compressor impeller, and the inlet blade angle of the variable inlet blade angle type guide vanes is gradually increased along the vane height direction.

Further, the angle range of the inlet blade angle β (included angle between the tangent line of the median line and the radial direction) at the blade top of the variable inlet blade angle type guide blade is 50-80 degrees, the angle range of the inlet blade angle α (included angle between the tangent line of the median line and the radial direction) at the blade root is 40-70 degrees, and the difference between α and α, which is greater than β, is 5-15 degrees.

Furthermore, the change rule of the variable-inlet-blade-angle type guide blade in the direction from the blade root to the blade top is linear change.

Compared with the prior art, the invention has the following advantages:

the variable-inlet-blade-angle type guide vane vaned diffuser takes the distribution condition of the actual incoming flow airflow angle into consideration, so that the change of the inlet blade angle with different blade heights is matched with the change of the incoming flow airflow angle, the friction loss and the separation loss caused by the overlarge difference between the airflow angle and the inlet blade angle are effectively reduced, the flow field in the vane channel of the vaned diffuser is effectively improved, the efficiency of the vaned diffuser is optimized, and the flow characteristic of a centrifugal compressor is improved.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is a perspective view of a vaned diffuser configuration according to an embodiment of the present disclosure;

FIG. 2 is a schematic view of a vaned diffuser structure in combination with a centrifugal compressor according to an embodiment of the present invention;

FIG. 3 is a schematic view of an inlet vane angle of a variable inlet vane angle type guide vane according to an embodiment of the present invention;

fig. 4 is a schematic view of the distribution of the flow angle of the inlet of the vaned diffuser (i.e., the outlet of the compressor wheel) along the blade height direction according to an embodiment of the present invention.

Description of reference numerals:

1-ring diffuser base plate; 2-variable inlet blade angle type guide vanes; 3-a vaned diffuser; 4-compressor impeller.

Detailed Description

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention. Furthermore, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first," "second," etc. may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art through specific situations.

The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

A vaned diffuser structure with variable inlet blade angle type guide vanes is disclosed, as shown in figure 1, comprising a ring diffuser bottom plate 1 and a plurality of variable inlet blade angle type guide vanes 2 uniformly distributed along the circumferential direction on the ring diffuser bottom plate, as shown in figure 2, a schematic diagram of the combination of a vaned diffuser 3 and a centrifugal compressor impeller 4 is shown, the channel rotation direction (from the inner diameter of the bottom plate to the outer diameter) of the variable inlet blade angle guide vanes 2 on the vaned diffuser 3 is the same as the rotation direction (in the figure, both are counterclockwise direction) of the compressor impeller 4;

the inlet blade angle of the variable inlet blade angle type guide vane 2 gradually increases along the blade height direction, and fig. 3 shows an inlet blade angle schematic view of the variable inlet blade angle type guide vane 2, wherein the flying inlet blade angle β at the blade top of the guide vane 2 is 50 degrees to 80 degrees, the inlet blade angle α at the blade root is 40 degrees to 70 degrees, β is greater than α degrees, and the difference between the two angles is 5 degrees to 15 degrees.

In order to simplify the processing, the angle change rule of the inlet blade from the blade root to the blade top along the blade height direction is linear change. Fig. 4 is a schematic view showing the distribution of the flow angle of the inlet of the vaned diffuser (i.e., the outlet of the compressor wheel) along the vane height, and it is apparent that the flow angle increases continuously along the direction of increasing the vane height.

When the supercharger with the vane diffuser works, the compressor impeller 4 rotates to compress air to do work, and airflow enters the vane diffuser 3 from the impeller outlet, passes through a section of vaneless diffuser and then enters the guide vane 2 channel, so that further efficient diffusion is completed.

The invention replaces the traditional guide vane with the variable-inlet vane angle type guide vane, and aims at the distribution condition of the gas airflow angle at different vane heights at the outlet (inlet of the vane diffuser) of the impeller, so that the change of the inlet vane angle at different vane heights is matched with the change of the incoming flow angle, the friction loss and the separation loss caused by too large difference between the airflow angle and the inlet vane angle are effectively reduced, the flow field in the vane passage of the vane diffuser is effectively improved, the efficiency of the vane diffuser is optimized, and the flow characteristic of the centrifugal compressor is improved.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. The utility model provides a have a vane diffuser structure with become inlet blade angle type guide vane which characterized in that: the variable-inlet-blade-angle-type guide vane comprises an annular diffuser bottom plate (1) and a plurality of variable-inlet-blade-angle-type guide vanes (2) which are uniformly distributed along the circumferential direction, wherein the rotating direction of a blade channel of each variable-inlet-blade-angle-type guide vane (2) is the same as the rotating direction of a compressor impeller, and the inlet blade angle of each variable-inlet-blade-angle-type guide vane (2) is gradually increased along the blade height direction.

2. The structure of the vaned diffuser with variable inlet vane angle type guide vanes of claim 1, wherein the angle range of the inlet vane angle β at the vane tip of the variable inlet vane angle type guide vane (2) is 50-80 °, the angle range of the inlet vane angle α at the vane root is 40-70 °, and the difference between α and α of β is 5-15 °.

3. A vaned diffuser structure with variable inlet vane angle type guide vanes as claimed in claim 1 wherein: the change rule of the variable-inlet-blade-angle type guide blade (2) in the direction from the blade root to the blade top is linear change.