JP2010174726A - Centrifugal compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a centrifugal compressor adjusting channel cross section area by a simple structure. <P>SOLUTION: The centrifugal compressor 10 includes a channel area adjustment device 18. The channel area adjustment device 18 includes a channel area adjustment device capable of adjusting channel cross section area by extending in a channel direction of a scroll 13 and having a function selectively changing over between a state dividing a channel 14 to an outside area 15a communicating to a diffuser 12 and an inside area 15b at radial direction inside of the outside area 15a and a state not dividing the channel 14 into those areas. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a centrifugal compressor, and more particularly to a centrifugal compressor capable of adjusting a scroll channel cross-sectional area.

  Conventionally, a centrifugal compressor provided with a scroll that introduces a fluid blown from an impeller through a diffuser to form a spiral flow path is known.

  In order to reduce the size of the centrifugal compressor, it is required to reduce the scroll size. Therefore, scrolls of a type that can keep the outer diameter dimension constant regardless of the flow rate have been adopted. However, in this type of scroll, the larger the flow rate ratio relative to the size, the more the scroll shape is bent in the axial direction from the diffuser outlet. Therefore, when the fluid from the diffuser enters the scroll, the flow is rapidly bent and separation occurs, or an area where no flow is formed is created, resulting in a large fluid loss in the scroll and a decrease in scroll performance. There's a problem.

  In order to cope with such a problem, a configuration has been proposed in which a movable wall is provided in the scroll, and the flow passage cross-sectional area of the scroll is adjusted by moving the movable wall (for example, see Patent Document 1 below). reference).

  In the centrifugal compressor disclosed in Patent Document 1, a movable wall that is movable in the axial direction is provided inside the scroll, and the flow passage cross-sectional area of the scroll is changed by moving the movable wall in the axial direction by an actuator.

JP-A-63-83499

  Since the centrifugal compressor disclosed in Patent Document 1 is configured to change the flow path cross-sectional area by positioning the movable wall at an appropriate position within the movable range, a mechanism and control for positioning are required. The configuration tends to be complicated.

  This invention is made | formed in view of said problem, and makes it a subject to provide the centrifugal compressor which can implement | achieve adjustment of a flow-path cross-sectional area with a simple structure.

In order to solve the above problems, the centrifugal compressor of the present invention employs the following technical means.
(1) The present invention provides a centrifugal compressor provided with a scroll that introduces a fluid blown from an impeller through a diffuser to form a spiral flow path, and extends in a spiral shape in the flow path direction of the scroll. A function of selectively switching between a state in which the cross-sectional area is adjustable and the flow path is divided into an outer region communicating with the diffuser and an inner region radially inward of the outer region, and a state in which these regions are not partitioned. It has the channel area adjustment device which has these.

  According to said structure, a flow-path area adjustment apparatus selectively switches to the state which partitions a flow path into an outer area | region and an inner area | region, and the state which does not partition. In the state where the flow path is divided into the outer area and the inner area, the portion through which the fluid flows is limited only to the outer area, so the cross-sectional area of the flow path becomes small. In a state where the flow path is not divided into the outer area and the inner area, the portion through which the fluid flows is the entire inside of the scroll, so that the flow path cross-sectional area becomes large. As described above, by adopting a simple configuration in which the wall that partitions the outer region and the inner region is opened and closed, adjustment of the flow path cross-sectional area can be realized with a simple configuration.

(2) In the above centrifugal compressor, the flow path area adjusting device has a movable wall that is inserted into the scroll and configured to be movable in the axial direction.

  According to the above configuration, the outer region and the inner region can be partitioned by inserting the movable wall deeply into the scroll, and the outer region and the inner region are not partitioned by moving the movable wall in the direction of pulling out the scroll. it can. Therefore, the flow path area adjusting device can be realized with a simple configuration.

(3) Further, in the above centrifugal compressor, the flow path area adjusting device has a plurality of openings formed at intervals along the flow path direction, and has a flow path direction fixed in the scroll. A fixed wall extending; and a movable valve that opens and closes the plurality of openings of the fixed wall.

  According to said structure, since a fixed wall and a movable valve can be stored in a scroll, space can be saved compared with the movable wall which moves to an axial direction.

(4) In the above centrifugal compressor, the movable valve is a plurality of swing valves provided corresponding to each of the plurality of openings.

  According to said structure, a movable valve is realizable with a simple structure.

(5) In the above centrifugal compressor, the movable valve is a slide valve that is movable along the fixed wall.

  According to said structure, a movable valve is realizable with a simple structure.

  ADVANTAGE OF THE INVENTION According to this invention, adjustment of a flow-path cross-sectional area is realizable with a simple structure by employ | adopting the simple structure of opening and closing the wall divided into an outer area | region and an inner area | region.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, the same code | symbol is attached | subjected to the common part in each figure, and the overlapping description is abbreviate | omitted.

[First Embodiment]
FIG. 1 is a cross-sectional view showing a main part of a centrifugal compressor 10 according to a first embodiment of the present invention, where (A) shows a state at a small flow rate and (B) shows a state at a large flow rate. Yes.
In FIG. 1, the centrifugal compressor 10 includes an impeller 11, a diffuser 12, a scroll 13, and a flow path area adjusting device 18.

  The impeller 11 is rotationally driven by a drive source (such as an electric motor) not shown, and sucks and accelerates fluid from the front surface. The fluid may be a liquid other than a gas such as air.

  The diffuser 12 is an annular flow channel located on the outer side in the radial direction of the impeller 11, and introduces the fluid exiting from the impeller 11. The diffuser 12 is provided with a plurality of blades 12a for rectifying fluid at intervals in the circumferential direction. The wing 12a may be a fixed wing having a fixed wing angle or a variable wing that changes the wing angle. Further, the wing 12a may be omitted.

  The scroll 13 constitutes a spiral channel 14 for introducing the fluid from the diffuser 12. The spiral flow path 14 communicates with a discharge port (not shown), and the fluid given pressure energy by the scroll 13 is discharged from the discharge port.

  The impeller 11, the diffuser 12, and the scroll 13 preferably have predetermined heat resistance so that their functions can be maintained even when exposed to a high-temperature fluid.

  The flow channel area adjusting device 18 extends in the flow channel direction of the scroll 13 and can adjust the cross-sectional area of the flow channel 14. The outer region 15 a that communicates with the diffuser 12 through the flow channel 14 and the inner side in the radial direction from the outer region 15 a. A function of selectively switching between a state of partitioning into the inner region 15b and a state of not partitioning these regions.

  As shown in FIG. 1, the flow path area adjusting device 18 of the present embodiment includes a movable wall 19 configured to be movable in the axial direction with respect to the scroll 13 and an actuator 20 that moves the movable wall 19 in the axial direction. Have.

  The movable wall 19 is a plate-like member that spirally extends along the flow path 14 of the scroll 13, and is inserted into the flow path 14 through the wall of the scroll 13. The movable wall 19 and the scroll 13 are sealed so that fluid pressurized by a seal structure (not shown) does not leak from the scroll 13 to the outside. In addition, it is preferable that the movable wall 19 has predetermined heat resistance like other members.

  The driving method of the actuator 20 is not limited to a specific one. For example, the rotation of the rotary motor may be converted into a linear motion by a conversion mechanism and the movable wall 19 may be moved in the axial direction, or the movable wall 19 may be moved directly in the axial direction by a linear motor. Alternatively, the actuator 20 may be omitted, and the movable wall 19 may be manually inserted and removed to adjust the position shown in FIG. 1 (A) or (B).

Next, the operation of the first embodiment will be described.
When the centrifugal compressor 10 is operated at a small flow rate, the movable wall 19 is inserted deeply into the scroll 13 as shown in FIG. 1 (A) so that the outer region 15a and the inner region 15b are partitioned. Thus, in the state where the flow path 14 is divided into the outer area 15a and the inner area 15b, the portion through which the fluid flows in the scroll 13 is limited only to the outer area 15a, and thus the flow path cross-sectional area is reduced. Therefore, since the cross-sectional area of the flow path is suitable for a small flow rate, it is possible to suppress separation due to rapid bending of the flow and generation of a flow non-formation region, and to maintain the scroll 13 performance.

  On the other hand, when the centrifugal compressor 10 is operated at a large flow rate, the movable wall 19 is moved in the direction of pulling out from the scroll 13 as shown in FIG. 1 (B) so that the outer region 15a and the inner region 15b are not partitioned. Thus, in a state where the flow path 14 is not partitioned into the outer area 15a and the inner area 15b, the portion through which the fluid flows in the scroll 13 is the entire inside of the scroll 13, so that the cross-sectional area of the flow path is increased. Therefore, since the cross-sectional area of the flow path is suitable for a large flow rate, the scroll 13 performance can be maintained.

  As described above, according to the centrifugal compressor 10 of the present invention, the channel cross-sectional area is set in two patterns, large and small, so that a positioning mechanism and control as in the prior art (for example, Patent Document 1) are unnecessary. is there. That is, by adopting a simple configuration that opens and closes a wall that partitions the outer region and the inner region, adjustment of the channel cross-sectional area can be realized with a simple configuration.

  Further, according to the configuration of the first embodiment, the outer wall 15 a and the inner area 15 b can be partitioned by inserting the movable wall 19 deeply into the scroll 13, and the movable wall 19 is moved in the direction of pulling out from the scroll 13. It is possible to keep the outer region 15a and the inner region 15b from being partitioned. Therefore, the flow path area adjusting device 18 can be realized with a simple configuration.

[Second Embodiment]
FIG. 2 is a cross-sectional view showing a main part of the centrifugal compressor 10 according to the second embodiment of the present invention. In FIG. 2, the impeller 11, the diffuser 12, and the scroll 13 are the same structures as 1st Embodiment.

  The flow path area adjusting device 18 of the second embodiment includes a fixed wall 21 having a plurality of openings 21a formed at intervals along the flow path direction and extending in the flow path direction and fixed in the scroll 13. And a movable valve 22 that opens and closes the plurality of openings 21 a of the fixed wall 21.

  The movable valve 22 in the second embodiment is a plurality of oscillating valves 22A provided corresponding to the plurality of openings 21a. The swing valve 22 </ b> A is swingably connected to the fixed wall 21 by a hinge portion 23. The swing valve 22A may be driven by a suitable actuator or may be moved manually.

  The direction in which the swing valve 22A opens may be on either the outer region 15a side or the inner region 15b side, but opens on the inner region 15b side and the tip contacts the inner wall surface of the scroll 13 as in the configuration example of FIG. When configured to be supported by the inner wall surface, fluttering of the swing valve 22A in the open state can be prevented.

  In FIG. 2, the end of the movable valve 22 (right end in the illustrated example) has a swing center, but the center of the movable valve 22 (for example, the center) may have a swing center.

Next, the operation of the second embodiment will be described.
When the centrifugal compressor 10 is operated at a small flow rate, the swing valve 22A is closed and the outer region 15a and the inner region 15b are partitioned. Thus, in the state where the flow path 14 is divided into the outer area 15a and the inner area 15b, the portion through which the fluid flows in the scroll 13 is limited only to the outer area 15a, and thus the flow path cross-sectional area is reduced.

  On the other hand, when the centrifugal compressor 10 is operated at a large flow rate, the swing valve 22A is opened and the outer region 15a and the inner region 15b are not partitioned. Thus, in a state where the flow path 14 is not partitioned into the outer area 15a and the inner area 15b, the portion through which the fluid flows in the scroll 13 is the entire inside of the scroll 13, so that the cross-sectional area of the flow path is increased.

FIG. 3 is a diagram showing another configuration example of the flow path area adjusting device 18 of the second embodiment, and shows the scroll 13 and the flow path area adjusting device 18 when viewed in a cross section perpendicular to the axial direction. .
In the configuration example of FIG. 2, the direction of the swing axis of the swing valve 22A is perpendicular to the axial direction. However, as in another configuration example shown in FIG. 3, the swing shaft of the swing valve 22A. The direction of the heart may be the same direction as the axial direction.

  FIG. 3 shows the swing valve 22A in an open state. The closed swing valve 22A is in a position indicated by a broken line in the figure. When the opening 21a is closed by the swing valve 22A, the flow path 14 is partitioned into an outer region 15a and an inner region 15b.

  In FIG. 3, the swing center is located at the end of the swing valve 22A (the upstream end in the flow direction in the illustrated example), but the swing center may be located at an intermediate position (for example, the center) of the swing valve 22A.

Also by the configuration of the second embodiment, by adopting a simple configuration that opens and closes the wall that partitions the outer region 15a and the inner region 15b, the adjustment of the channel cross-sectional area can be realized with a simple configuration.
Further, according to the second embodiment, the fixed wall 21 and the movable valve 22 (oscillating valve 22A) can be accommodated in the scroll 13, so that space can be saved compared to the movable wall 19 that moves in the axial direction. .

[Third Embodiment]
FIG. 4 is a view showing the main part of the centrifugal compressor 10 according to the third embodiment of the present invention, and shows the scroll 13 and the flow path area adjusting device 18 when viewed in a cross section perpendicular to the axial direction. .
The flow path area adjusting device 18 according to the third embodiment includes a fixed wall 21 having a plurality of openings 21 a formed at intervals along the flow path direction and extending in the flow path direction and fixed in the scroll 13. And a movable valve 22 that opens and closes the plurality of openings 21 a of the fixed wall 21.

  The movable valve 22 in the third embodiment is a plurality of slide valves 22B that can move along the fixed wall 21, and is provided corresponding to each of the plurality of openings 21a. By making the slide direction of the slide valve 22B the fluid flow direction as shown by the arrow in FIG. 4B, the movable range of the slide valve 22B can be increased. The slide valve 22B may be driven by an appropriate actuator or may be moved manually.

Next, the operation of the third embodiment will be described.
When the centrifugal compressor 10 is operated at a small flow rate, the slide 22B is closed as shown in FIG. 4A, and the outer region 15a and the inner region 15b are separated. Thus, in the state where the flow path 14 is divided into the outer area 15a and the inner area 15b, the portion through which the fluid flows in the scroll 13 is limited only to the outer area 15a, and thus the flow path cross-sectional area is reduced.

  On the other hand, when the centrifugal compressor 10 is operated at a large flow rate, the slide valve 22B is opened as shown in FIG. 4B, and the outer region 15a and the inner region 15b are not partitioned. Thus, in a state where the flow path 14 is not partitioned into the outer area 15a and the inner area 15b, the portion through which the fluid flows in the scroll 13 is the entire inside of the scroll 13, so that the cross-sectional area of the flow path is increased.

Also by the configuration of the third embodiment, by adopting a simple configuration of opening and closing the wall that partitions the outer region 15a and the inner region 15b, the adjustment of the flow path cross-sectional area can be realized with a simple configuration.
Further, according to the third embodiment, since the fixed wall 21 and the movable valve 22 (slide valve 22B) can be accommodated in the scroll 13, space can be saved compared to the movable wall 19 that moves in the axial direction.

  Although the embodiments of the present invention have been described above, the embodiments of the present invention disclosed above are merely examples, and the scope of the present invention is not limited to these embodiments. . The scope of the present invention is indicated by the description of the scope of claims, and further includes meanings equivalent to the description of the scope of claims and all modifications within the scope.

It is sectional drawing which shows the principal part of the centrifugal compressor which concerns on 1st Embodiment of this invention. It is sectional drawing which shows the principal part of the centrifugal compressor which concerns on 2nd Embodiment of this invention. It is a figure which shows another structural example of the flow-path area adjustment apparatus in the centrifugal compressor which concerns on 2nd Embodiment of this invention. It is a figure which shows the principal part of the centrifugal compressor which concerns on 3rd Embodiment of this invention.

DESCRIPTION OF SYMBOLS 10 Centrifugal compressor 11 Impeller 12 Diffuser 12a Blade | wing 13 Scroll 14 Flow path 15a Outer area 15b Inner area 18 Flow area adjustment device 19 Movable wall 20 Actuator 21 Fixed wall 21a Opening part 22 Movable valve 22A Swing valve 22B Slide valve 23 Hinge Part

Claims (5)

In a centrifugal compressor provided with a scroll that introduces a fluid blown out from an impeller through a diffuser and constitutes a spiral flow path,
A state in which the flow path cross-sectional area can be adjusted by extending spirally in the flow path direction of the scroll, and the flow path is partitioned into an outer area communicating with the diffuser and an inner area radially inward from the outer area; A centrifugal compressor comprising a flow path area adjusting device having a function of selectively switching to a state in which these regions are not partitioned.   The centrifugal compressor according to claim 1, wherein the flow path area adjusting device has a movable wall that is inserted into the scroll and configured to be movable in the axial direction.   The flow path area adjusting device has a plurality of openings formed at intervals along a flow path direction, a fixed wall extending in the flow path direction fixed in the scroll, and the plurality of the fixed walls. The centrifugal compressor according to claim 1, further comprising a movable valve that opens and closes the opening.   The centrifugal compressor according to claim 3, wherein the movable valve is a plurality of swing valves provided corresponding to the plurality of openings. The centrifugal compressor according to claim 3, wherein the movable valve is a slide valve that is movable along the fixed wall.

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