CN113914994A

CN113914994A - Air inlet bypass recirculation device with variable prerotation centrifugal compressor

Info

Publication number: CN113914994A
Application number: CN202111212859.5A
Authority: CN
Inventors: 杨新乐; 叶顺宏; 李颂; 冯建增
Original assignee: Liaoning Technical University
Current assignee: Liaoning Technical University
Priority date: 2021-10-19
Filing date: 2021-10-19
Publication date: 2022-01-11

Abstract

The invention relates to an air inlet bypass recirculation device of a centrifugal compressor with variable prerotation, which mainly comprises a bypass channel, an adjusting ring and prerotation blades, wherein the bypass channel is arranged between the inner end wall and the outer end wall of a volute and is connected with a compressor flow channel through a bypass groove, the inner end wall and the outer end wall of the volute are connected through a reinforcing rib to fix the inner end wall of the volute, the adjusting ring is positioned at the outer convex part of the outer end wall of the volute, a limit screw is in sliding connection with a straight groove to adjust the circumferential position of the adjusting ring, the prerotation blades are connected in the bypass channel through a crank, and the prerotation blades are limited in the rotation range by the limit groove. The prerotation blades are arranged in the bypass channel, prerotation treatment is carried out on airflow flowing through the bypass channel, and gas flow in the bypass channel is improved, so that the relative Mach number at the inlet of the impeller is reduced, generation of shock waves is reduced, the efficiency of the gas compressor is improved, and the aim of widening the working stability of the gas compressor is fulfilled.

Description

Air inlet bypass recirculation device with variable prerotation centrifugal compressor

Technical Field

The invention relates to an air inlet bypass recirculation device of a centrifugal compressor, and belongs to the technical field of turbochargers.

Background

The turbocharger has inherent advantages in the aspects of improving the power of an engine, reducing fuel consumption and the like, the centrifugal compressor is used as an important component of the turbocharger, and the expansion of the stable working range of the centrifugal compressor has important significance for improving the working efficiency of the turbocharger and further improving the capability of improving the fuel combustion effect of the engine. Slotting treatment is performed on a centrifugal compressor casing as a common passive control method, and the slotting treatment is widely applied to stability expansion of the compressor. A bypass recirculation channel is formed at the front end of a centrifugal impeller of the gas compressor through slotting treatment, when the gas compressor is close to a surge point, the pressure of the bypass channel is greater than that of a main runner, part of gas enters an inlet of the gas compressor through the bypass channel, and the surge point is pushed to a smaller flow; when the working condition is close to blockage, gas at the inlet is accumulated, the pressure of the main channel is greater than that of the bypass channel, part of the gas enters the bypass channel from the inlet and directly flows to the middle and rear sections of the centrifugal blade wind guide wheel through the bypass groove, and the blockage gas flow of the wind guide section at the inlet is improved. However, the conventional recirculation device only focuses on the influence of the shape and parameter change of the bypass groove on the performance of the compressor, but neglects the whole flow condition inside the bypass channel, when the air inlet bypass recirculation channel works, the gas flow in the channel is distributed in an inclined way at a certain angle to form a part of vortex, and the flow can have a certain influence on the performance of the centrifugal compressor. Conventional recirculation devices ignore flow conditions within the channels and, therefore, further improvements are needed.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide an air inlet bypass recirculation device of a centrifugal compressor with variable prewhirl.

In order to achieve the above object, the present invention provides the following technical solutions.

The utility model provides a take variable centrifugal compressor that prerevolves to admit air bypass recirculation device, mainly includes bypass passageway, adjustable ring, prerevolves the blade, bypass passageway links to each other with the compressor runner through the bypass groove between spiral case inner end wall and spiral case outer end wall, link to each other in order to fix spiral case inner end wall by the strengthening rib between spiral case inner end wall and the spiral case outer end wall, the adjustable ring is located the convex part portion of spiral case outer end wall, stop screw connects in spacing screw hole department, with straight flute sliding connection, adjustable adjusting ring circumferential position.

The pre-rotation vanes are connected in the bypass channel through a crank, and the rotation range of the pre-rotation vanes is limited by the limiting grooves.

The crank is provided with a first connecting column connected with the first connecting hole, a second connecting column connected with the second connecting hole, the front end of the preselection blade is provided with a third connecting hole, and the crank is provided with a third connecting column connected with the third connecting hole.

The crank screw is connected with the adjusting ring, penetrates through the inclined groove and is connected to the crank threaded hole, and is in sliding connection with the inclined groove.

Further, the pre-rotation blade is limited in rotation range by the limiting groove, and the rotation angle range of the limiting groove is 0-50 degrees relative to the axial direction.

Further, the pre-rotation vanes are uniformly distributed in the bypass channel along the circumferential direction, the interval angle is 45 degrees,

the number of the pre-rotation blades is 8 in total.

Furthermore, the section of the prewhirl blade is in a streamline shape with a wide front part and a narrow back part, the front end of the prewhirl blade is provided with a third connecting hole, the third connecting hole is connected with a third connecting column, the third connecting column is provided with a boss, and the boss is matched with the through groove to realize synchronous rotation of the prewhirl blade and the crank.

Further, a certain included angle exists between the bypass groove and the plane where the inlet of the compressor is located, and the included angle ranges from 20 degrees to 24 degrees.

Further, the adjusting ring is provided with straight flute and chute, the straight flute is in along circumference evenly distributed on the adjusting ring, the interval angle is 90, the chute is in along circumference evenly distributed on the adjusting ring, the interval angle is 45.

The present invention has the following advantages over the prior art.

(1) The invention relates to an air inlet bypass recirculation device of a centrifugal compressor with variable prerotation, which is characterized in that an adjustable prerotation blade is arranged in a bypass channel to prerotate airflow flowing through the bypass channel, so that the gas flow in the bypass channel is improved, the relative Mach number at the inlet of an impeller is reduced, the generation of shock waves is reduced, the efficiency of the compressor is improved, and the aim of widening the working stability of the compressor is fulfilled.

(2) The invention has simple structure, easy realization and lower cost.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention.

FIG. 1 is an assembly view of an inlet bypass recirculation assembly for a centrifugal compressor with variable pre-rotation according to the present invention.

FIG. 2 is a partial block diagram of the volute of the bypass recirculation system of the present invention.

Fig. 3 is a block diagram of the bypass recirculation system adjustment ring according to the present invention.

FIG. 4 is a block diagram of the bypass recirculation system pre-rotation vanes of the present invention.

FIG. 5 is a partial cross-sectional structural view of a bypass recirculation device crank according to the present invention.

FIG. 6 is a view of the construction of the bypass recirculation system pre-rotation vanes and crank assembly according to the present invention.

Reference numbers in the figures: 1. a volute inner end wall; 2. a volute outer end wall; 3. reinforcing ribs; 4. a bypass channel; 5. an adjusting ring; 6. a limit screw; 7. a crank screw; 8. a bypass groove; 9. pre-rotating blades; 10. a crank; 11. a limiting threaded hole; 12. a first connection hole; 13. a limiting groove; 14. a second connection hole; 15. a straight groove; 16. a chute; 17. a third connection hole; 18. a first connecting column; 19. a second connecting column; 20. a third connecting column; 21. a crank threaded hole; 22. a boss; 23. a through groove.

Detailed Description

The preferred embodiments of the present invention will be described in conjunction with the accompanying drawings, and it will be understood that they are described herein for the purpose of illustration and explanation and not limitation.

In the description of the present invention, it is to be understood that the terms "front", "rear", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, unless otherwise specified and limited, it is to be understood that the terms "connected" and "connected" are used herein to indicate that the terms

"connected" is to be understood in a broad sense as meaning either directly connected or indirectly connected through intervening media, as is common in the art

The skilled person will understand the specific meaning of the above terms according to the specific situation.

With reference to fig. 1 and 2, the invention relates to an air inlet bypass recirculation device of a centrifugal compressor with variable prerotation, which mainly comprises a bypass channel 4, an adjusting ring 5 and prerotation vanes 9.

The bypass channel 4 is arranged between the inner end wall 1 of the volute and the outer end wall 2 of the volute and is connected with a compressor flow channel through a bypass groove 8, the inner end wall 1 of the volute and the outer end wall 2 of the volute are connected through a reinforcing rib 3 to fix the inner end wall 1 of the volute, and a certain included angle is formed between the bypass groove 8 and the plane where the compressor inlet is located, and the included angle ranges from 20 degrees to 24 degrees. When the compressor is close to a surge point, the pressure of the bypass channel is greater than that of the main channel, part of gas enters the inlet of the compressor from the bypass channel, and the surge point is pushed to a smaller flow; when the working condition is close to blockage, gas at the inlet is accumulated, the pressure of the main channel is greater than that of the bypass channel, part of the gas enters the bypass channel from the inlet and directly flows to the middle and rear sections of the centrifugal blade wind guide wheel through the bypass groove, and the blockage gas flow of the wind guide section at the inlet is improved.

The adjusting ring 5 is located the protruding portion of the outer end wall 2 of the volute, the limit screw 6 is connected in the limit screw hole 11, and the straight flute 15 is in sliding connection, and is not hard up the limit screw 6 is adjustable during the limit screw 6 the circumferential position of the adjusting ring 5 can be adjusted during the fastening of the limit screw 6.

The pre-rotation vane 9 is connected in the bypass channel 4 through a crank 10, the pre-rotation vane 9 is limited in rotation range by the limit groove 13, the rotation angle range of the limit groove 13 is 0-50 degrees from the axial included angle, the crank 10 is provided with a first connecting column 18 connected with the first connecting hole 12, a second connecting column 19 connected with the second connecting hole 14, the front end of the pre-rotation vane 9 is provided with a third connecting hole 17, the crank 10 is provided with a third connecting column 20 connected with the third connecting hole 17, the cross section of the pre-rotation vane 9 is in a streamline shape with a wide front part and a narrow back part, the third connecting hole 17 is provided with a through groove 23, the third connecting column 20 is provided with a boss 22, the boss 22 is matched with the through groove 23 to realize the synchronous rotation of the pre-rotation vane 9 and the crank 10, one end of the crank 10 is connected with the adjusting ring 5 through the crank screw 7, the crank screw 7 is connected to the crank threaded hole 21 through the inclined groove 16 and is in sliding connection with the inclined groove 16.

The adjusting ring 5 is rotated, the straight groove 13 moves circumferentially along the outer end wall 2 of the volute under the limitation of the limiting screw 6, the chute 16 moves synchronously, the chute 16 drives the crank screw 17 to move, the crank 10 swings back and forth along with the crank screw, the crank 10 rotates through the first connecting column 18 and the second connecting column 19 to drive the pre-rotation vane 9 to move, two side surfaces of the pre-rotation vane 9 can freely rotate within the range of 0-50 degrees, and the swing limitation is performed by the wall surfaces at two ends of the limiting groove 13.

The pre-rotation blades 9 are uniformly distributed in the bypass passage 4 along the circumferential direction, the interval angle is 45 degrees, and the number of the pre-rotation blades is 8. The adjusting ring 5 is provided with straight flute 15 and chute 16, straight flute 15 is in along circumference evenly distributed on the adjusting ring 5, the interval angle is 90, chute 16 is in along circumference evenly distributed on the adjusting ring 5, the interval angle is 45, the straight flute 15 realizes the circumferential direction of adjusting ring 5, and the swing of crank 10 is realized to chute 16.

When the air flow passes through the bypass channel, the blade load in the blade tip area can be reduced due to the pre-rotation blades and the angle of the bypass groove, so that the speed of the blade tip leakage flow flowing out of the exhaust groove becomes lower. The air flow flowing through the bypass slots impacts the tip leakage flow generated upstream and prevents the extension of the tip leakage flow, deflecting the trajectory of the tip leakage vortex. The bypass channel discharges fluid adjacent the casing, and as a result of the reduction in blockage, the shock wave moves downstream thereby attenuating the interaction of the shock wave with the tip leakage flow and inhibiting the increase in blockage due to the interaction between the shock wave and the tip leakage vortex.

Claims

1. The inlet bypass recirculation device with the variable pre-rotation centrifugal compressor mainly comprises a bypass channel (4), an adjusting ring (5) and pre-rotation vanes (9), and is characterized in that the bypass channel (4) is arranged between an inner end wall (1) and an outer end wall (2) of the volute and is connected with a compressor flow channel through a bypass groove (8), the inner end wall (1) and the outer end wall (2) of the volute are connected through a reinforcing rib (3) to fix the inner end wall (1) of the volute, the adjusting ring (5) is positioned at an outer convex part of the outer end wall (2) of the volute, a limiting screw (6) is connected to a limiting threaded hole (11) and is in sliding connection with a straight groove (15), and the circumferential position of the adjusting ring (5) can be adjusted;

the pre-rotation vanes (9) are connected in the bypass channel (4) through a crank (10), and the rotation range of the pre-rotation vanes (9) is limited by the limiting grooves (13);

the crank (10) is provided with a first connecting column (18) connected with the first connecting hole (12), a second connecting column (19) connected with the second connecting hole (14), the front end of the preselection blade (9) is provided with a third connecting hole (17), and the crank (10) is provided with a third connecting column (20) connected with the third connecting hole (17);

one end of the crank (10) is connected with the adjusting ring (5) through the crank screw (7), and the crank screw (7) penetrates through the inclined groove (16) to be connected to the crank threaded hole (21) and is in sliding connection with the inclined groove (16).

2. The inlet bypass recirculation device with variable prerotation for centrifugal compressors according to claim 1, characterized in that the prerotation vanes (9) are limited in rotation range by the limiting grooves (13), the limiting grooves (13) being arranged in a rotation angle range of 0 ° to 50 ° from the axial direction.

3. The inlet bypass recirculation device with variable pre-rotation for a centrifugal compressor according to claim 1, characterized in that the pre-rotation vanes (9) are uniformly distributed in the bypass channel (4) along the circumferential direction, the spacing angle is 45 °, and the number of pre-rotation vanes (9) is 8 in total.

4. The intake bypass recirculation device with the variable pre-rotation for the centrifugal compressor is characterized in that the cross section of the pre-rotation blade (9) is in a streamline shape with a wide front part and a narrow back part, the front end of the pre-rotation blade is provided with the third connecting hole (17) and is connected with the third connecting column (20), the third connecting hole (17) is provided with a through groove (23), the third connecting column (20) is provided with a boss (22), and the boss (22) is matched with the through groove (23) to realize the synchronous rotation of the pre-rotation blade (9) and the crank (10).

5. The inlet bypass recirculation device with variable prerotation for centrifugal compressors according to claim 1, characterized in that said bypass channel (8) has an angle with the plane of the compressor inlet, which is comprised between 20 ° and 24 °.

6. The inlet bypass recirculation device with variable prerotation for a centrifugal compressor according to claim 1, characterized in that said adjusting ring (5) is provided with straight slots (15) and inclined slots (16), said straight slots (15) being uniformly distributed circumferentially on said adjusting ring (5) at an angular interval of 90 °, said inclined slots (16) being uniformly distributed circumferentially on said adjusting ring (5) at an angular interval of 45 °.