CN219035131U - Axial moving type adjustable slotted vane diffuser and centrifugal compressor thereof - Google Patents

Abstract

The utility model provides an axial moving type adjustable slotted vane diffuser and a centrifugal compressor thereof. The centrifugal compressor comprises a centrifugal impeller, an air inlet cover, an impeller cover, a blade diffuser, a volute, balls and a clamping ring. The blade diffuser consists of a diffuser case, a diffuser back plate and a diffuser blade body. The diffuser blade body is provided with a plurality of diffuser blades, the diffuser blades penetrate through the diffuser case and the diffuser back plate, the diffuser blades are provided with diffuser notches, and the diffuser blades are carried by the diffuser blade body to axially reciprocate perpendicular to the diffuser end face, so that the diffuser notches are opened and closed. The utility model has simple structure and convenient processing, and can effectively widen the stable flow range of the centrifugal compressor and reduce the pneumatic performance loss as much as possible.

Description

Axial moving type adjustable slotted vane diffuser and centrifugal compressor thereof

Technical Field

The utility model relates to the technical field of centrifugal compressors, in particular to an axial-movement type adjustable slotted vane diffuser and a centrifugal compressor thereof.

Background

In a turbocharger matched with an engine, a centrifugal compressor is an important component for realizing gas compression and transportation, and generally comprises pneumatic elements such as a centrifugal impeller, a diffuser, a volute and the like. The diffuser is communicated with the upstream circumferential periodical rotating impeller and the downstream circumferential divergent static volute, and plays important roles of guiding, rectifying and secondary supercharging.

According to different structural forms, besides the vaneless diffuser, the diffuser also comprises a vane diffuser, namely one or more rows of vanes are distributed between a diffuser case and a diffuser back plate. Compared with a vaneless diffuser, the vane diffuser has higher static pressure recovery coefficient, can better improve the flow field of a diffuser channel near the design flow, and improves the total pressure ratio and the heat insulation efficiency of the centrifugal compressor. However, since the diffuser blades and the diffuser casing or the diffuser back plate are of an integral static structure, the boundary layer separation problem between the airflow and the stress surface of the blades inevitably occurs in the guiding and rectifying process of the non-design working condition, and stall is induced in advance, and the flow area is reduced. In engineering application, proper blade end face assembly gaps are found to play a role in stability expansion sometimes, and further research proves that the blade slotting has a better stability expansion effect. But the heat insulation efficiency and the total pressure ratio of the grooving working condition are reduced to different degrees, especially the amplitude reduction near the design flow is maximum, and the difference is more obvious along with the increase of the rotation speed of the impeller and the increase of the grooving height.

In summary, how to widen the stable flow area of the centrifugal compressor by using the diffuser blade slotting technology and reduce the aerodynamic performance loss as much as possible is an important problem that needs to be solved by those skilled in the art.

Disclosure of Invention

According to the technical problems that the heat insulation efficiency and the total pressure ratio of the grooving working conditions are reduced to different degrees, especially the amplitude reduction is the largest near the design flow, and the difference is more obvious along with the increase of the rotation speed of the impeller and the increase of the grooving height, the axial movable adjustable grooving blade diffuser and the centrifugal compressor thereof are provided. According to the utility model, the diffuser notch is arranged on the diffuser blade, and the width and the length of the notch are controlled according to different working conditions, so that the pressure field, the speed field and the like between the blades are regulated, and the aerodynamic loss of the centrifugal compressor is reduced as much as possible while stall is restrained.

The utility model adopts the following technical means:

an axially movable adjustable slotted vane diffuser comprising: the diffuser comprises a diffuser casing, a diffuser back plate and a diffuser blade body, wherein the diffuser casing, the diffuser back plate and the diffuser blade body are sequentially arranged, a plurality of diffuser blades are arranged on the diffuser blade body, the diffuser blades penetrate through the diffuser casing and the diffuser back plate, diffuser notches are formed in the diffuser blades, and the diffuser blade body carries the diffuser blades to axially reciprocate perpendicular to the diffuser end face so as to realize opening and closing of the diffuser notches.

Further, the diffuser casing is provided with a casing inner end face and a casing outer end face, the diffuser back plate is provided with a back plate inner end face and a back plate outer end face, the diffuser blade body is provided with a blade inner end face and a blade outer end face, and one end of the diffuser blade is connected to the blade inner end face;

the inner end face of the casing and the inner end face of the back plate are two adjacent and spaced end faces, a flow passage space is formed between the two end faces, and the inner end face of the casing and the inner end face of the back plate form an axial boundary of a flow passage of the diffuser.

Further, the diffuser slot comprises a tip diffuser slot arranged at the tip of the diffuser blade and a root diffuser slot arranged at the root of the diffuser blade; when the diffuser blades do not move, the blade top diffuser notch and the blade root diffuser notch are respectively positioned in the diffuser case and the diffuser back plate and are in an unopened state;

taking the diffuser blades to move to the direction of the inner end surface of the casing to move forward so as to open blade root diffuser notches, and forming a first runner communicated with the runner space between the blade root diffuser notches and the inner end surface of the back plate;

and the diffuser blade moves in the direction of the inner end surface of the back plate to move reversely so as to open the tip diffuser notch, and a second flow passage communicated with the flow passage space is formed between the tip diffuser notch and the inner end surface of the casing.

Further, the diffuser notch is a single notch or multiple notches; the diffuser notch is arranged on one axial side or two axial sides of the diffuser blade; the diffuser slots are provided at the leading edge, trailing edge, or other chordwise location of the diffuser blades.

Further, the diffuser notch has a single-step or multi-step structure; the slotting area of the notch of the diffuser is regulated in a step or stepless way; the stepless regulating arc line of the notch of the diffuser is circular arc line, parabola or hyperbola, and the like, and is convex or concave relative to the flow passage.

Further, the number of the diffuser blades is one or two, and the diffuser blades are circumferentially distributed along the central axis of the diffuser blade body; the diffuser blades are airfoil-shaped, circular-arc-shaped, triangular or other.

Further, a plurality of casings She Xingcao circumferentially distributed are penetratingly arranged on the diffuser casing, a plurality of back plates She Xingcao circumferentially distributed are penetratingly arranged on the diffuser back plate, and the diffuser blades penetrate through the back plate She Xingcao and are inserted into the casing She Xingcao; the diffuser casing, the diffuser back plate and the diffuser blade body are assembled through the casing She Xingcao, the back plate She Xingcao and the diffuser blade.

Further, a plurality of blade body axial grooves are formed in the circumferential outer wall of the diffuser blade body, the diffuser blade body is connected with the volute, a plurality of volute axial grooves are formed in the position, corresponding to the blade body axial grooves, on the volute, and balls are arranged in the blade body axial grooves and the volute axial grooves in the same group;

after the spiral case and the diffuser blade body are connected through the ball, the ball is constrained by the axial groove of the blade body and the axial groove of the spiral case together, so that the axial movement of the diffuser blade body is realized.

Further, the volute connected with the diffuser blade body is provided with a volute inner end face, a volute clamping groove is further formed in the volute, a clamping ring is connected in the volute clamping groove in a matched mode, and axial displacement limiting of the diffuser blade body is achieved through the volute inner end face and the clamping ring.

The utility model also provides a centrifugal compressor, which comprises a centrifugal impeller, an air inlet cover, an impeller cover, a volute, balls, a clamping ring and the blade diffuser;

the centrifugal impeller is arranged in a middle mounting hole of the blade diffuser, the air inlet cover, the impeller cover and the blade diffuser are sequentially arranged on the volute, the air inlet cover and the impeller cover are sleeved outside the centrifugal impeller, the ball and the snap ring are connected between the blade diffuser and the volute, and the snap ring is positioned on the outer side of the ball.

Compared with the prior art, the utility model has the following advantages:

according to the axial moving type adjustable slotted vane diffuser and the centrifugal compressor thereof provided by the utility model, the diffuser casing, the diffuser back plate and the diffuser vanes are assembled as mutually independent parts. The diffuser blades are arranged on the diffuser blade body. The diffuser blade body is not stationary, but does not rotate, but moves (axially moves) perpendicular to the diffuser end faces (e.g., the inner end face of the casing and the inner end face of the back plate). The diffuser blade body can move in two directions, and when the diffuser blade body moves forward, the blade root diffuser notch is opened, and when the diffuser blade body moves backward, the blade root diffuser notch is opened. The width and the length of the diffuser notch are determined according to the moving distance, and the regulation of the slotting area of the diffuser notch is determined according to the structural form of the diffuser notch. According to different working conditions, the width and the length of the slot are controlled to regulate the pressure field, the speed field and the like between the blades, and reduce the aerodynamic loss of the centrifugal compressor as much as possible while inhibiting the occurrence of stall. When the stall flow condition is approached, the diffuser blade body is gradually moved axially along with the flow reduction, the diffuser notch is opened, and the slotting area of the diffuser notch is increased. For the slotting position and the moving direction, the judgment is based on the diffuser stall position. For example, for a vaneless diffuser with early stall at the inner face of the near-back disk, moving the diffuser blade body toward the inner face of the case, the root diffuser slot opens and gradually increases the slotted area. When the stall flow working condition is kept away from, the diffuser blade body is moved reversely, the diffuser notch is restored to the back of the diffuser end face, the diffuser runner is internally provided with no diffuser notch, and leakage loss and blending loss are reduced. When the diffuser blades are divided into two groups, the consistency of the two groups is increased, so that small-flow stall can be better controlled, and one group of blades completely exits the diffuser flow passage to the rear of the diffuser end face when the flow rate is high. In summary, the vane diffuser provided by the utility model has a simple structure and is convenient to process, and the aerodynamic performance loss of the vane diffuser can be reduced as much as possible while the stable flow range of the centrifugal compressor is effectively widened.

In summary, the technical scheme of the utility model can solve the problems that the heat insulation efficiency and the total pressure ratio of the grooving working condition in the prior art are reduced to different degrees, especially the amplitude reduction near the design flow is maximum, and the difference is more obvious along with the increase of the rotation speed of the impeller and the increase of the grooving height.

For the reasons, the utility model can be widely popularized in the fields of centrifugal compressors and the like.

Drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are some embodiments of the present utility model, and other drawings may be obtained according to the drawings without inventive effort to a person skilled in the art.

Fig. 1 is an assembled sectional view of a centrifugal compressor in accordance with an embodiment of the present utility model, the compressor being a centrifugal compressor with an axially movable adjustable slotted vane diffuser.

Fig. 2 is another assembled cross-sectional view of a centrifugal compressor in an embodiment of the utility model with a diffuser blade body not shown in section.

FIG. 3 is an assembled cross-sectional view of a vane diffuser in accordance with an embodiment of the present utility model, the diffuser being an axially movable, adjustable slotted vane diffuser.

FIG. 4 is an assembled and disassembled view (exploded view) of a vane diffuser including a diffuser case, a diffuser back plate, and a diffuser vane body, according to an embodiment of the present utility model.

Fig. 5 is a schematic structural view of a diffuser casing according to an embodiment of the present utility model.

Fig. 6 is a schematic view of a diffuser back plate according to an embodiment of the present utility model.

Fig. 7 is a schematic view of a diffuser blade body according to an embodiment of the present utility model.

Fig. 8 is an assembled cross-sectional view of a volute, ball and diffuser blade body in an embodiment of the utility model.

Fig. 9 is a schematic structural view of a volute in an embodiment of the utility model.

FIG. 10 is a two-dimensional schematic of an operational state of a diffuser blade according to an embodiment of the present utility model, wherein (a) is a schematic of an unopened state of a diffuser slot, (b) is a schematic of an opened state of a diffuser slot at a tip of a blade, and (c) is a schematic of an opened state of a diffuser slot at a root of a blade.

Fig. 11 is a two-dimensional schematic diagram of a diffuser slot according to an embodiment of the present utility model, where (a), (c), and (e) are single-step diffuser slots, and (b), (d), and (f) are multi-step diffuser slots.

In the figure: 1. a centrifugal impeller; 2. an air inlet cover; 3. an impeller cover; 4. a vane diffuser; 5. a volute; 6. a ball; 7. a clasp; 8. a diffuser casing; 9. a diffuser back plate; 10. a diffuser blade body; 11. an inner end surface of the case; 12. the outer end face of the casing; 13. a casing She Xingcao; 14. the inner end surface of the back plate; 15. the outer end surface of the back plate; 16. a back plate She Xingcao; 17. the inner end surface of the blade body; 18. the outer end face of the blade body; 19. blade body axial slots; 20. diffuser blades; 21. a diffuser slot; 22. the inner end face of the volute; 23. a volute axial groove; 24. and a volute clamping groove.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present utility model more apparent, the technical solutions of the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model, and it is apparent that the described embodiments are some embodiments of the present utility model, but not all embodiments of the present utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

The utility model provides an axial moving type adjustable slotted vane diffuser and a centrifugal compressor thereof. Belongs to the technical field of centrifugal compressors.

The utility model relates to a centrifugal compressor, which comprises a centrifugal impeller 1, an air inlet cover 2, an impeller cover 3, a vane diffuser 4, a volute 5, balls 6 and a clamping ring 7. The centrifugal impeller 1 is arranged in a middle mounting hole of the blade diffuser 4, the air inlet cover 2, the impeller cover 3 and the blade diffuser 4 are sequentially arranged on the volute 5 in sequence, the air inlet cover 2 and the impeller cover 3 are sleeved outside the centrifugal impeller 1, the ball 6 and the snap ring 7 are connected between the blade diffuser 4 and the volute 5, and the snap ring 7 is positioned on the outer side of the ball 6.

In the centrifugal compressor, the axial moving type adjustable slotted vane diffuser 4 comprises a diffuser case 8, a diffuser back plate 9 and a diffuser vane body 10.

Preferably, the diffuser casing 8 includes a casing inner end face 11 and a casing outer end face 12, and a plurality of casings She Xingcao circumferentially distributed are disposed on the diffuser casing 8.

Preferably, the back disk 9 of the diffuser includes an inner end surface 14 of the back disk and an outer end surface 15 of the back disk, and a plurality of back disks She Xingcao circumferentially distributed on the back disk 9 of the diffuser.

Preferably, the diffuser blade body 10 comprises a blade inner end face 17 and a blade outer end face 18, the diffuser blade body 10 is provided with a blade body axial groove 19 and a diffuser blade 20, the mounting end of the diffuser blade 20 is connected to the blade inner end face 17, and the diffuser blade 20 is further provided with a diffuser notch 21. The diffuser blade body 10 carries the diffuser blade 20 to axially reciprocate perpendicular to the diffuser end face, so that the diffuser notch 21 is opened and closed.

Preferably, the inner casing end face 11 and the inner back disk end face 14 form an axial boundary of the diffuser flow passage. The inner end face 11 of the case and the inner end face 14 of the back plate are two adjacent and spaced end faces, a flow passage space is formed between the two end faces, and the diffuser notch 21 comprises a tip diffuser notch arranged at the tip of the diffuser blade 20 and a root diffuser notch arranged at the root of the diffuser blade 20; when the diffuser blades 20 are not moved, the blade tip diffuser notch and the blade root diffuser notch are respectively positioned in the diffuser case 8 and the diffuser back plate 9 and are in an unopened state; the diffuser blades 20 move to the direction of the inner end face 11 of the casing to move forward so as to open blade root diffuser notches, and a first runner communicated with a runner space is formed between the blade root diffuser notches and the inner end face 14 of the back plate; the diffuser blades 20 are moved to move reversely towards the direction of the inner end surface 14 of the back plate so as to open the tip diffuser notch, and a second flow passage communicated with the flow passage space is formed between the tip diffuser notch and the inner end surface 11 of the casing.

Preferably, the diffuser case 8, the diffuser back plate 9 and the diffuser blade body 10 are assembled by the case She Xingcao, the back plate She Xingcao, and the diffuser blades 20. Wherein the non-mounting end of the diffuser blade 20 extends through the back disk blade slot 16 and is inserted into the casing She Xingcao. The diffuser blades 20 are driven by the diffuser blade body 10 to move axially along the casing She Xingcao and the back disk She Xingcao.

Preferably, the volute 5 comprises a volute inner end surface 22, and a volute axial groove 23 and a volute clamping groove 24 are formed in the volute 5.

Preferably, after the volute 5 and the diffuser blade body 10 are connected by the balls 6, the balls 6 are constrained by the blade body axial groove 19 and the volute axial groove 23, so that the diffuser blade body 10 moves axially.

Preferably, after the volute clamping groove 24 is matched with the clamping ring 7, the axial displacement limit of the diffuser blade body 10 is realized by the volute inner end face 22 and the clamping ring 7.

Preferably, the diffuser blades 20 may have a airfoil shape, a circular arc shape, a triangular shape, or other forms.

Preferably, the number of sets of diffuser blades 20 may be one set or two sets.

Preferably, the diffuser slot 21 may be single-slot or multi-slot.

Preferably, the diffuser slot 21 may be provided on one axial side or both axial sides of the diffuser vane 20.

Preferably, the diffuser slot 21 may be provided at the leading edge, trailing edge, or other chordwise location of the diffuser blade 20.

Preferably, the diffuser slot 21 may be configured in a single step, multiple step manner.

Preferably, the slotted area of the diffuser slot 21 can be adjusted in steps or steplessly.

Preferably, the stepless adjustment curve of the diffuser notch 21 can be circular curve, parabolic curve or hyperbolic curve, etc., and can be convex or concave relative to the flow passage.

When the stall flow working condition is far away, the diffuser notch is arranged behind the inner end face of the back plate and the inner end face of the casing, and the diffuser flow passage area is not involved. When the flow condition is close to stall flow, the diffuser blade body moves along the axial direction continuously along with the reduction of the flow, after the diffuser notch is opened, the width and the length of the diffuser notch are increased, the leakage flow is increased, the area of an upstream fluid low-speed blocking area is reduced, the separation flow of the boundary layer of the downstream blade is restrained, and therefore the working flow area of the centrifugal compressor is widened. After the stall flow working condition is kept away from again, the diffuser blade body should be moved reversely, so that the diffuser notch is restored to the rear of the inner end face of the casing or the inner end face of the back plate, no channel leakage flow exists in the diffuser flow channel, the leakage loss and the mixing loss of fluid are reduced, and the aerodynamic performance loss of the centrifugal compressor is reduced.

Example 1

The embodiment of the utility model discloses an axial moving type adjustable slotted vane diffuser and a centrifugal compressor thereof. The structure is simple, the processing is convenient, and the problem of pneumatic performance loss caused by slotting leakage flow can be reduced as much as possible while the working flow area of the centrifugal compressor is effectively widened.

The structure of the embodiment of the utility model is shown in fig. 1 and 2, and comprises a centrifugal impeller 1, an air inlet cover 2, an impeller cover 3, a vane diffuser 4, a volute 5, balls 6 and a clamping ring 7.

As shown in fig. 3 and 4, the vane diffuser 4 includes a diffuser case 8, a diffuser back plate 9, and a diffuser blade body 10.

As shown in fig. 5, the diffuser casing 8 includes a casing inner end surface 11 and a casing outer end surface 12, and the diffuser casing 8 is provided with a casing She Xingcao.

The diffuser back plate 9 is structured as shown in fig. 6, the diffuser back plate 9 includes a back plate inner end surface 14, a back plate outer end surface 15, and the diffuser back plate 9 is provided with a back plate She Xingcao.

The diffuser blade body 10 is structured as shown in fig. 7, the diffuser blade body 10 includes a blade inner end surface 17 and a blade outer end surface 18, the diffuser blade body 10 is provided with a blade body axial groove 19, a diffuser blade 20, and the diffuser blade 20 is provided with a diffuser notch 21. In this embodiment, a set of diffuser blades 20 are provided, circumferentially distributed about the central axis of the diffuser blade body 10.

The assembly of the scroll 5, the ball 6 and the diffuser blade body 10 is as shown in fig. 8, and the axial movement of the diffuser blade body 10 is realized by the axial restriction of the scroll axial groove 23 of the scroll 5 and the blade body axial groove 19 of the diffuser blade body 10 under the condition of rolling connection of the ball 6.

The structure of the volute 5 is shown in fig. 9, the volute 5 comprises a volute inner end surface 22, and the volute 5 is provided with a volute axial groove 23 and a volute clamping groove 24. The volute clamping groove 24 is matched with the clamping ring 7, so that the clamping ring 7 and the inner end face 22 of the volute are used for restraining the axial movement of the diffuser blade body 10.

As shown in fig. 10, the diffuser blade 20 is operated in a state in which (a) of fig. 10 is a state in which the diffuser notch 21 is not opened, (b) of fig. 10 is a state in which the diffuser notch 21 at the tip is opened, and (c) of fig. 10 is a state in which the diffuser notch 21 at the root is opened.

The diffuser slot 21 is shown in fig. 11, wherein (a), (c) and (e) in fig. 11 are single-step diffuser slots 21; fig. 11 (b), (d), and (f) show a multi-step diffuser slot 21; fig. 11 (a), (b) are diffuser slots 21 with stage adjustment; fig. 11 (c), (d), (e), (f) are infinitely adjustable diffuser slots 21; fig. 11 (c) and (d) show convex diffuser slots 21; fig. 11 (e) and (f) show concave diffuser notches 21.

The diffuser case 8, the diffuser back plate 9 and the diffuser blade body 10 are assembled by the case She Xingcao, the back plate She Xingcao, and the diffuser blades 20. The inner end face 11 of the casing and the inner end face 14 of the back plate form the axial boundary of the diffuser flow passage. When the stall flow condition is not approached, the diffuser notch 21 in the diffuser blade 20 is behind the case inner end face 11 of the diffuser case 8 and the back plate inner end face 14 of the diffuser back plate 9, and the flow passage area is not involved, as shown in fig. 10 (a). When the stall flow condition is approached, the diffuser blades 20 move continuously along the axial direction along with the flow reduction, the diffuser notch 21 is opened, the width and length of the diffuser notch 21 are increased, the leakage flow rate is increased, the area of the low-speed blocking area of the fluid is reduced, and the separation flow of the boundary layers is restrained, so that the flow area range of the centrifugal compressor is widened, as shown in fig. 10 (b) or fig. 10 (c). After the stall flow condition is kept away again, the diffuser blades 20 are moved reversely, so that the diffuser notch 21 returns to the back of the diffuser end face (the inner end face 11 of the casing or the inner end face 14 of the back disc), no channel leakage flow exists in the diffuser flow channel, and leakage loss and blending loss are reduced, so that the aerodynamic performance loss of the centrifugal compressor is reduced.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present utility model, and not for limiting the same; although the utility model has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the utility model.

Claims (10)

1. An axially movable adjustable slotted vane diffuser, comprising: the diffuser comprises a diffuser casing (8), a diffuser back plate (9) and a diffuser blade body (10) which are sequentially arranged, wherein a plurality of diffuser blades (20) are arranged on the diffuser blade body (10), the diffuser blades (20) penetrate through the diffuser casing (8) and the diffuser back plate (9), diffuser notches (21) are formed in the diffuser blades (20), and the diffuser blade body (10) is used for carrying out axial reciprocating movement perpendicular to the diffuser end faces, so that the diffuser notches (21) are opened and closed.

2. The axially movable adjustable slotted vane diffuser according to claim 1, characterized in that the diffuser casing (8) has a casing inner face (11) and a casing outer face (12), the diffuser back plate (9) has a back plate inner face (14) and a back plate outer face (15), the diffuser vane body (10) has a vane inner face (17) and a vane outer face (18), one end of the diffuser vane (20) is connected to the vane inner face (17);

the inner end face (11) of the casing and the inner end face (14) of the back plate are two adjacent and spaced end faces, a flow passage space is formed between the two end faces, and the inner end face (11) of the casing and the inner end face (14) of the back plate form an axial boundary of a diffuser flow passage.

3. The axially movable adjustable slotted vane diffuser of claim 2, wherein the diffuser slot (21) includes a tip diffuser slot provided at a tip of the diffuser vane (20) and a root diffuser slot provided at a root of the diffuser vane (20); when the diffuser blades (20) are not moved, the blade top diffuser notch and the blade root diffuser notch are respectively positioned in the diffuser case (8) and the diffuser back plate (9) and are in an unopened state;

taking diffuser blades (20) to move towards the direction of the inner end face (11) of the casing to move forward so as to open blade root diffuser notches, and forming a first runner communicated with the runner space between the blade root diffuser notches and the inner end face (14) of the back plate;

the diffuser blades (20) are taken to move in the direction of the inner end face (14) of the back disc to move reversely so as to open the tip diffuser notch, and a second flow passage communicated with the flow passage space is formed between the tip diffuser notch and the inner end face (11) of the casing.

4. An axially movable adjustable slotted vane diffuser according to claim 1, 2 or 3, characterized in that the diffuser slot (21) is a single slot or multiple slots; the diffuser notch (21) is arranged on one axial side or two axial sides of the diffuser blade (20); the diffuser slot (21) is provided at a leading or trailing edge of the diffuser blade (20).

5. The axially movable adjustable slotted vane diffuser according to claim 4, characterized in that the diffuser slot (21) is of single-step or multi-step construction; the slotting area of the diffuser notch (21) is regulated in a step mode or in a stepless mode; the stepless regulating arc line of the diffuser notch (21) is a circular arc line, a parabola or a hyperbola, and is convex or concave relative to the flow passage.

6. An axially movable adjustable slotted vane diffuser according to claim 1, 2 or 3, characterized in that the number of groups of diffuser vanes (20) is one or two, circumferentially distributed along the central axis of the diffuser vane body (10); the diffuser blades (20) are airfoil-shaped, circular arc-shaped or triangular in shape.

7. The axial moving type adjustable slotted vane diffuser according to claim 1, characterized in that a plurality of casings She Xingcao (13) distributed circumferentially are penetratingly arranged on the diffuser casing (8), a plurality of back plates She Xingcao (16) distributed circumferentially are penetratingly arranged on the diffuser back plate (9), and the diffuser vanes (20) penetrate through the back plates She Xingcao (16) and are inserted into the casings She Xingcao (13); the diffuser casing (8), the diffuser back plate (9) and the diffuser blade body (10) are assembled through the casing She Xingcao (13), the back plate She Xingcao (16) and the diffuser blades (20).

8. The axial movable type adjustable slotted vane diffuser according to claim 1, characterized in that a plurality of vane axial grooves (19) are formed in the circumferential outer wall of the diffuser vane body (10), the diffuser vane body (10) is connected with a volute (5), a plurality of volute axial grooves (23) are formed in the volute (5) at positions corresponding to the vane axial grooves (19), and balls (6) are arranged in the vane axial grooves (19) and the volute axial grooves (23) in the same group;

after the spiral case (5) and the diffuser blade body (10) are connected through the ball (6), the ball (6) is constrained by the blade body axial groove (19) and the spiral case axial groove (23) together, so that the axial movement of the diffuser blade body (10) is realized.

9. The axially movable adjustable slotted vane diffuser according to claim 1 or 8, characterized in that a volute (5) connected with the diffuser vane body (10) is provided with a volute inner end surface (22), a volute clamping groove (24) is further formed in the volute (5), a clamping ring (7) is connected in the volute clamping groove (24) in a matched manner, and the axial displacement limit of the diffuser vane body (10) is realized through the volute inner end surface (22) and the clamping ring (7).

10. A centrifugal compressor comprising a centrifugal impeller (1), an inlet shroud (2), an impeller shroud (3), a volute (5), balls (6), a snap ring (7) and a vane diffuser (4) according to any one of claims 1 to 9;

the centrifugal impeller (1) is arranged in a middle mounting hole of the blade diffuser (4), the air inlet cover (2), the impeller cover (3) and the blade diffuser (4) are sequentially arranged on the volute (5), the air inlet cover (2) and the impeller cover (3) are sleeved outside the centrifugal impeller (1), the ball (6) and the clamping ring (7) are connected between the blade diffuser (4) and the volute (5), and the clamping ring (7) is positioned on the outer side of the ball (6).

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