U.S. patent application number 15/747987 was filed with the patent office on 2018-08-09 for inlet guide vane, compressor, inlet guide vane attachment method, and centrifugal compressor production method.
This patent application is currently assigned to MITSUBISHI HEAVY INDUSTRIES, LTD.. The applicant listed for this patent is MITSUBISHI HEAVY INDUSTRIES, LTD.. Invention is credited to Jun KOGA, Shintaro OMURA.
Application Number | 20180223866 15/747987 |
Document ID | / |
Family ID | 58631418 |
Filed Date | 2018-08-09 |
United States Patent
Application |
20180223866 |
Kind Code |
A1 |
KOGA; Jun ; et al. |
August 9, 2018 |
INLET GUIDE VANE, COMPRESSOR, INLET GUIDE VANE ATTACHMENT METHOD,
AND CENTRIFUGAL COMPRESSOR PRODUCTION METHOD
Abstract
An inlet guide vane includes vane main bodies (42) having a
pressure surface (S1) and a suction surface (S2) which extend along
a radial-direction axial line (Ar). Each of the pressure surface
(S1) and the suction surface (S2) has a blade-shaped surface along
a surface of an imaginary blade shape (Pv) having a blade-like
cross-sectional shape. At least one of the pressure surface (S1)
and the suction surface (S2) has a thin portion-forming surface
(St) which recedes toward an inside of the imaginary blade shape
(Pv) more than the surface of the imaginary blade shape (Pv).
Inventors: |
KOGA; Jun; (Tokyo, JP)
; OMURA; Shintaro; (Tokyo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MITSUBISHI HEAVY INDUSTRIES, LTD. |
Tokyo |
|
JP |
|
|
Assignee: |
MITSUBISHI HEAVY INDUSTRIES,
LTD.
Tokyo
JP
|
Family ID: |
58631418 |
Appl. No.: |
15/747987 |
Filed: |
July 5, 2016 |
PCT Filed: |
July 5, 2016 |
PCT NO: |
PCT/JP2016/069880 |
371 Date: |
January 26, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F05D 2240/123 20130101;
F05D 2240/125 20130101; F05D 2250/51 20130101; F04D 29/462
20130101; F04D 17/12 20130101; F04D 29/444 20130101 |
International
Class: |
F04D 29/44 20060101
F04D029/44; F04D 17/12 20060101 F04D017/12 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 26, 2015 |
JP |
2015-209875 |
Claims
1. An inlet guide vane comprising: vane main bodies having a
pressure surface and a suction surface which extend in a radial
direction of a rotary shaft, wherein each of the pressure surface
and the suction surface has a blade-shaped surface along a surface
of an imaginary blade shape having a blade-like cross-sectional
shape, and at least one of the pressure surface and the suction
surface has a thin portion-forming surface which recedes toward an
inside of the imaginary blade shape more than the surface of the
imaginary blade shape.
2. The inlet guide vane according to claim 1, wherein the vane main
body has a front end surface on an end portion on an inside in the
radial direction, the thin portion-forming surface is formed in a
front end-side region connected to the front end surface on one of
the pressure surface and the suction surface, and the blade-shaped
surface on one of the pressure surface and the suction surface is
formed in a base end-side region of the thin portion-forming
surface on an outside in the radial direction.
3. The inlet guide vane according to claim 2, wherein the thin
portion-forming surface is formed along a blade central line of the
imaginary blade shape.
4. The inlet guide vane according to claim 2, wherein the front end
surface forms a blade shape along the imaginary blade shape, and
the thin portion-forming surface is formed so as to, as the thin
portion-forming surface runs from an edge portion of one of the
pressure surface and the suction surface on the front end surface
toward the outside in the radial direction, extend toward the other
of the pressure surface and the suction surface.
5. The inlet guide vane according to claim 2, wherein one of the
pressure surface and the suction surface has a connection surface
that is configured to connect a level difference between the
blade-shaped surface and the thin portion-forming surface.
6. The inlet guide vane according to claim 1, wherein the thin
portion-forming surface is formed on one of the pressure surface
and the suction surface so as to be sandwiched by the blade-shaped
surface from both the inside in the radial direction and the
outside in the radial direction.
7. The inlet guide vane according to claim 1, wherein the imaginary
blade shape becomes smaller in a similar shape as the blade-like
cross-sectional shape runs from the outside in the radial direction
to the inside in the radial direction.
8. The inlet guide vane according to claim 1, wherein, in the
imaginary blade shape, the blade-like cross-sectional shape forms a
linearly symmetric shape having the blade central line as a
symmetric axis.
9. A compressor comprising: the inlet guide vane according to claim
1; a casing in which a suction port that is configured to support
the inlet guide vane is formed; and an impeller that is configured
to compress fluid suctioned from the suction port.
10. An inlet guide vane attachment method for attaching a plurality
of inlet guide vanes to a suction port formed in a casing of a
compressor in a circumferential direction of the suction port at
intervals, wherein, in the inlet guide vane, each of a pressure
surface and a suction surface has a blade-shaped surface along a
surface of an imaginary blade shape having a blade-like
cross-sectional shape, and at least one of the pressure surface and
the suction surface has a thin portion-forming surface which
recedes toward an inside of the imaginary blade shape more than a
surface of the imaginary blade shape, the attachment method
comprising: a step of attaching a first inlet guide vane to an
inner circumferential side of the casing; a step of attaching a
second inlet guide vane at an interval with respect to the first
inlet guide vane in the circumferential direction; and a step of
attaching a third inlet guide vane between the first inlet guide
vane and the second inlet guide vane in the circumferential
direction, wherein, in the step of attaching the third inlet guide
vane, a portion of the third inlet guide vane on an inside in a
radial direction which includes the thin portion-forming surface is
inserted into a gap between the first inlet guide vane and the
second inlet guide vane, and then the third inlet guide vane is
moved to an outside in the radial direction.
11. A centrifugal compressor production method comprising: a step
of preparing the casing and the plurality of inlet guide vanes; the
respective steps of the inlet guide vane attachment method
according to claim 10; and a step of attaching a rotary shaft and
an impeller to an inner portion of the casing.
Description
TECHNICAL FIELD
[0001] The present invention relates to an inlet guide vane, a
compressor, an inlet guide vane attachment method, and a
centrifugal compressor production method.
[0002] Priority is claimed on Japanese Patent Application No.
2015-209875, filed on Oct. 26, 2015, the content of which is
incorporated herein by reference.
BACKGROUND ART
[0003] Among compressors that are used in, for example, turbo
refrigerators, there are compressors in which movable guide blades
(inlet guide vanes) are set in a suction port for suctioning
external air. A plurality of inlet guide vanes is provided in the
circumferential direction at intervals on the inner diameter side
of a circular suction port. Specifically, the respective inlet
guide vanes are attached to attachment portions arrayed in the
circumferential direction of the suction port.
[0004] In addition, in compressors having a constitution in which
no inner cylinder is provided in a suction port, each inlet guide
vane has a shape that extends from an inner circumferential surface
of the suction port to the center of the suction port. That is, in
the vicinity of the center of the suction port, a plurality of
inlet guide vanes gather from the outside in the radial direction
of the suction port (refer to Patent Document 1).
CITATION LIST
Patent Literature
[0005] [Patent Document 1] Japanese Unexamined Patent Application,
First Publication No. 2013-245575
SUMMARY OF INVENTION
Technical Problem
[0006] Meanwhile, when the above-described inlet guide vanes are
attached to the suction port, the respective inlet guide vanes are
inserted into the attachment portions provided in the suction port
from the inside of the suction port. Here, when a specific number
or more of inlet guide vanes are inserted, in order to prevent an
inlet guide vane to be attached from interfering with other inlet
guide vanes that have been already attached, it is necessary to
insert a portion of an inlet guide vane on the inside in the radial
direction into a gap between other adjacent inlet guide vanes and
then move the inlet guide vane toward the outside in the radial
direction.
[0007] Therefore, the thickness of the inlet guide vane needs to be
smaller than the gap between the inlet guide vanes. On the other
hand, from the viewpoint of improving the performance of the inlet
guide vane, it is vital to set the thickness of the respective
inlet guide vanes to be thick. Therefore, there is an intensifying
demand for an inlet guide vane capable of satisfying both the
performance of the inlet guide vane and the ease of assembly.
[0008] The present invention provides an inlet guide vane having
sufficient performance and ease of assembly, a compressor, an inlet
guide vane attachment method and a centrifugal compressor
production method.
Solution to Problem
[0009] An inlet guide vane according to a first aspect of the
present invention includes vane main bodies having a pressure
surface and a suction surface which extend in a radial direction of
a rotary shaft, each of the pressure surface and the suction
surface has a blade-shaped surface along a surface of an imaginary
blade shape having a blade-like cross-sectional shape, and at least
one of the pressure surface and the suction surface has a thin
portion-forming surface which recedes toward an inside of the
imaginary blade shape more than the surface of the imaginary blade
shape.
[0010] According to this constitution, the thin portion-forming
surface is formed on at least one of the pressure surface and the
suction surface of the vane main body. Therefore, when the
plurality of vane main bodies is arrayed on an inner
circumferential surface of a casing (suction port) of a compressor,
it is possible to easily put a vane main body that is to be
attached soon into a gap formed between vane main bodies that have
already been attached. Furthermore, the blade-shaped surface is
formed along the surface of the imaginary blade shape in a portion
excluding the thin portion-forming surface. Therefore, it is
possible to sufficiently ensure the performance of the inlet guide
vane.
[0011] In the inlet guide vane according to a second aspect of the
present invention, in the first aspect, the vane main body may have
a front end surface on an end portion on an inside in the radial
direction, the thin portion-forming surface may be formed in a
front end-side region connected to the front end surface on one of
the pressure surface and the suction surface, and the blade-shaped
surface on one of the pressure surface and the suction surface may
be formed in a base end-side region of the thin portion-forming
surface on an outside in the radial direction.
[0012] According to this constitution, the thin portion-forming
surface is formed on a front end side of the vane main body.
Therefore, when the plurality of vane main bodies is arrayed on the
inner circumferential surface of the casing (suction port) of the
compressor in a state in which the front ends thereof are gathered,
it is possible to easily put a vane main body that is to be
attached soon into a gap formed between vane main bodies that have
been already attached on the inside in the radial direction.
[0013] In the inlet guide vane according to a third aspect of the
present invention, in the second aspect, the thin portion-forming
surface may be formed along a blade central line of the imaginary
blade shape.
[0014] According to this constitution, there is no case in which
the vane main body becomes excessively thin due to the provision of
the thin portion-forming surface. Therefore, it is possible to
improve the ease of assembly of the inlet guide vane while
maintaining the structural strength of the vane main body.
[0015] In the inlet guide vane according to a fourth aspect of the
present invention, in the second aspect, the front end surface may
form a blade shape along the imaginary blade shape, and the thin
portion-forming surface may be formed so as to, as the thin
portion-forming surface runs from an edge portion of one of the
pressure surface and the suction surface on the front end surface
toward the outside in the radial direction, extend toward the other
of the pressure surface and the suction surface.
[0016] According to this constitution, there is no case in which
the vane main body becomes excessively thin even when the thin
portion-forming surface is provided. Therefore, it is possible to
more sufficiently ensure the structural strength of the vane main
body.
[0017] In the inlet guide vane according to a fifth aspect of the
present invention, in any one aspect of the second to fourth
aspects, one of the pressure surface and the suction surface may
have a connection surface that is configured to connect a level
difference between the blade-shaped surface and the thin
portion-forming surface.
[0018] According to this constitution, due to the formation of the
connection surface, it is possible to decrease the possibility that
the flow of fluid along the pressure surface and the suction
surface may separate.
[0019] In the inlet guide vane according to a sixth aspect of the
present invention, in the first aspect, the thin portion-forming
surface may be formed on one of the pressure surface and the
suction surface so as to be sandwiched by the blade-shaped surface
from both the inside in the radial direction and the outside in the
radial direction.
[0020] According to this constitution, it is possible to suppress
the size of the thin portion-forming surface being smaller compared
with a case in which the thin portion-forming surface is formed
throughout the entire region including the end portion on the
inside in the radial direction on one of the pressure surface and
the suction surface. Therefore, it is possible to further decrease
the separation of the flow of fluid caused by the formation of the
thin portion-forming surface.
[0021] In the inlet guide vane according to a seventh aspect of the
present invention, in any one aspect of the first to seventh
aspects, the imaginary blade shape may become smaller in a similar
shape as the blade-like cross-sectional shape runs from the outside
in the radial direction to the inside in the radial direction.
[0022] According to this constitution, in the region on the outside
in the radial direction in which the flow rate of fluid becomes
relatively faster, it is possible to relatively significantly
ensure the area of the imaginary blade shape. Therefore, it is
possible to more effectively guide fluid and improve the efficiency
of the inlet guide vane.
[0023] In the inlet guide vane according to an eighth aspect of the
present invention, in any one aspect of the first to seventh
aspects, in the imaginary blade shape, the blade-like
cross-sectional shape may form a linearly symmetric shape having
the blade central line as a symmetric axis.
[0024] According to this constitution, it is possible to
efficiently guide fluid using any surface of the pressure surface
and the suction surface of the vane main body.
[0025] A ninth aspect of the present invention includes the inlet
guide vane according to any one aspect of the first to eighth
aspects, a casing in which a suction port that is configured to
support the inlet guide vane is formed, and an impeller that is
configured to compress fluid suctioned from the suction port.
[0026] According to this constitution, it is possible to provide a
compressor having inlet guide vanes that are easily assembled.
[0027] An inlet guide vane attachment method according to a tenth
aspect of the present invention is an inlet guide vane attachment
method for attaching a plurality of inlet guide vanes to a suction
port formed in a casing of a compressor in a circumferential
direction of the suction port at intervals, in which, in the inlet
guide vane, each of a pressure surface and a suction surface has a
blade-shaped surface along a surface of an imaginary blade shape
having a blade-like cross-sectional shape, and at least one of the
pressure surface and the suction surface has a thin portion-forming
surface which recedes toward an inside of the imaginary blade shape
more than a surface of the imaginary blade shape, and the
attachment method includes a step of attaching a first inlet guide
vane to an inner circumferential side of the casing, a step of
attaching a second inlet guide vane at an interval with respect to
the first inlet guide vane in the circumferential direction, and a
step of attaching a third inlet guide vane between the first inlet
guide vane and the second inlet guide vane in the circumferential
direction, in which, in the step of attaching the third inlet guide
vane, a portion of the third inlet guide vane on an inside in a
radial direction which includes the thin portion-forming surface is
inserted into a gap between the first inlet guide vane and the
second inlet guide vane, and then the third inlet guide vane is
moved to an outside in the radial direction.
[0028] According to this method, it is possible to easily attach a
plurality of inlet guide vanes to a suction port formed in a casing
of a compressor without causing interference among them.
[0029] A centrifugal compressor production method according to an
eleventh aspect of the present invention includes a step of
preparing the casing and the plurality of inlet guide vanes, the
respective steps of the inlet guide vane attachment method
according to the tenth aspect, and a step of attaching a rotary
shaft and an impeller to an inner portion of the casing.
[0030] According to this method, it is possible to obtain a
centrifugal compressor including inlet guide vanes which can be
easily attached and have sufficient performance.
Advantageous Effects of Invention
[0031] According to the present invention, it is possible to
provide an inlet guide vane having sufficient performance and ease
of assembly, a compressor including the same, and an inlet guide
vane attachment method.
BRIEF DESCRIPTION OF DRAWINGS
[0032] FIG. 1 is a cross-sectional view showing a constitution of a
centrifugal compressor according to a first embodiment of the
present invention.
[0033] FIG. 2 is a schematic diagram showing an inlet guide vane
according to the first embodiment of the present invention.
[0034] FIG. 3 is a view of a vane main body according to the first
embodiment of the present invention seen in an axial line As
direction.
[0035] FIG. 4 is a cross-sectional view in a direction of an arrow
IV-IV in FIG. 3.
[0036] FIG. 5 is a view of a vane main body according to a second
embodiment of the present invention seen in the axial line As
direction.
[0037] FIG. 6 is a cross-sectional view in a direction of an arrow
VI-VI in FIG. 5.
[0038] FIG. 7 is a view of a vane main body according to a third
embodiment of the present invention seen in the axial line As
direction.
[0039] FIG. 8 is a cross-sectional view in a direction of an arrow
VIII-VIII in FIG. 7.
[0040] FIG. 9 is a view of a vane main body according to a fourth
embodiment of the present invention seen in the axial line As
direction.
[0041] FIG. 10 is a cross-sectional view in a direction of an arrow
X-X in FIG. 9.
[0042] FIG. 11 is a flowchart showing individual steps of a
centrifugal compressor production method according to an embodiment
of the present invention.
DESCRIPTION OF EMBODIMENTS
First Embodiment
[0043] A first embodiment of the present invention will be
described with reference to drawings. A compressor (centrifugal
compressor) according to the present embodiment includes a rotary
shaft 29, two impellers (a first impeller 21 and a second impeller
22), a casing 28, and an inlet guide vane V as shown in FIG. 1. The
rotary shaft 29 extends along an axial line As. The two impellers
(the first impeller 21 and the second impeller 22) are integrally
attached to the rotary shaft 29. The casing 28 forms a flow channel
for circulating fluid (air) by covering the first impeller 21 and
the second impeller 22 from the outer circumferential side. The
inlet guide vane V is provided on one side of the casing 28 in an
axial line direction.
[0044] The casing 28 has a casing main body 28A and a suction
casing 30A. In one side of the casing main body 28A in the axial
line As direction, a suction port 30 (suction casing 30A) for
drawing refrigerant gas from the outside is provided. While
described in detail below, the inlet guide vane V capable of
changing the angle depending on the operation status is attached to
an inner circumferential side of the suction port 30. In the other
side of the casing main body 28A in the axial line As direction, a
scroll 31 that ejects refrigerant gas is provided. In the casing
main body 28A, an inner space 32 that communicates with the suction
port 30 and the scroll 31 is formed.
[0045] The first impeller 21 and the second impeller 22 are
disposed in the inner space 32. The first impeller 21 and the
second impeller 22 form a first compression stage and a second
compression stage respectively. Each of the first impeller 21 and
second impeller 22 has a plurality of blades B that extends from
the inside toward the outside in the radial direction with respect
to the axial line As.
[0046] The plurality of blades B is arrayed in a circumferential
direction with respect to the axial line As at intervals. Between a
pair of blades B adjacent to each other in the circumferential
direction, a flow channel for circulating refrigerant gas is
formed. This flow channel gradually curves from the inside toward
the outside in the radial direction as the flow channel runs from
one side toward the other side in the axial line As direction.
[0047] The inner space 32 includes a return flow channel 33
connected to a downstream side of a flow channel of the first
impeller 21 and a suction flow channel 34 (inflow flow channel 34)
that is configured to connect the return flow channel 33 and an
upstream side of a flow channel of the second impeller 22. In the
following description, an actual body portion of a centrifugal
compressor 2 that forms the return flow channel 33 will be referred
to as a return flow channel-forming portion 33A. That is, the
return flow channel 33 includes a part of the casing 28 as the
return flow channel-forming portion 33A.
[0048] The return flow channel 33 circulates refrigerant gas from a
flow channel outlet port on the outside of the first impeller 21 in
the radial direction toward a flow channel inlet port on the inside
of the second impeller 22 in the radial direction. The return flow
channel 33 (return flow channel-forming portion 33A) has a return
bend portion 36, a straight flow channel 37, return vanes 38, and a
middle suction port 41.
[0049] A diffuser 35 guides refrigerant gas compressed by the first
impeller 21 to the outside in the radial direction. In the diffuser
35, the flow channel area that is seen in the radial direction
gradually increases as the flow channel runs from the inside in the
radial direction to the outside in the radial direction. On a
cross-section including the axial line As, wall surfaces of the
diffuser 35 on both sides in the axial line As direction extend in
parallel from the inside toward the outside in the radial
direction. An end portion of the diffuser 35 on the outside in the
radial direction is reversed toward the inside in the radial
direction through the return bend portion 36 and is then
communicated with the straight flow channel 37. Meanwhile, the wall
surfaces of the diffuser 35 on both sides in the axial line As
direction do not need to be perfectly parallel to each other at all
times and may be substantially parallel to each other.
[0050] The return bend portion 36 curves toward the outside in the
radial direction in the central portion on a cross-section
including the axial line As. In other words, the return bend
portion 36 curves in substantially an arc shape having one point on
the axial line As side as the center. The straight flow channel 37
extends from an end portion of the return bend portion 36 on the
downstream side toward the inside in the radial direction. In the
straight flow channel 37, a plurality of return vanes 38 is
radially arrayed around the axial line As.
[0051] In the suction flow channel 34 of the return flow channel 33
(that is, the flow channel inlet port of the second impeller 22),
movable vanes 50 capable of changing the angle depending on the
operation status are provided. A plurality of movable vanes 50 is
arrayed in the circumferential direction with respect to the axial
line As at intervals. The plurality of movable vane 50 is driven by
a driving device 51, and the angles thereof are changed.
[0052] Furthermore, in the straight flow channel 37, a middle
suction chamber 40 is provided. The middle suction chamber 40
merges refrigerant gas guided from the outside to a discharge flow
of the first impeller 21 and supplies the refrigerant gas to the
second impeller 22. The middle suction chamber 40 is an annular
space that surrounds the periphery of an inlet portion of the
second impeller 22. In the inside of the middle suction chamber 40
in the radial direction, the slit-like middle suction port 41 is
provided. This middle suction port 41 connects an inner portion of
the middle suction chamber 40 and the straight flow channel 37 of
the return flow channel.
[0053] Next, a detailed constitution of the inlet guide vane V will
be described with reference to FIG. 2. As shown in the same
drawing, the inlet guide vane V according to the present embodiment
has a plurality of attachment portions 42S formed in the suction
port 30 (suction casing 30A) and a plurality of vane main bodies 42
that is respectively supported by the attachment portions 42S.
[0054] Here, as shown in FIG. 1, the suction casing 30A (suction
port 30) has an inner circumferential surface having substantially
an arc shape when seen on a cross-section including the axial line
As. In addition, as shown in FIG. 2, the suction casing 30A
(suction port 30) has a circular cross-section when seen in the
axial line As direction. That is, the suction port 30 has a suction
space having a semicircular shape having one point on the axial
line As as the center.
[0055] In a region which is on the inside of the suction port 30
and is farthest away from the axial line As, the attachment
portions 42S for supporting the vane main bodies 42 are provided.
The plurality of attachment portions 42S is arrayed in the
circumferential direction with respect to the axial line As at
intervals along the inner circumferential surface of the suction
port 30. In the present embodiment, seven attachment portions 42S
are provided in the circumferential direction at equal intervals.
To these attachment portions 42S, the vane main bodies 42 are
attached respectively.
[0056] As shown in FIG. 1 or FIG. 2, the vane main body 42 is a
blade-like member formed into a thin plate shape. The vane main
body 42 has a support portion 43 and a blade portion 44. The
support portion 43 is supported by the attachment portion 42S. The
blade portion 44 extends from the support portion 43 toward the
inside in the radial direction with respect to the axial line As in
a state of being supported by the attachment portion 42S.
[0057] The support portion 43 is attached to the attachment portion
42S so as to be capable of rotating around a revolving axial line
that extends in the radial direction with respect to the axial line
As. That is, the support portion 43 is a member that serves as a
shaft for enabling the blade portion 44 to revolve around the
revolving axial line. Meanwhile, in the following description, an
axial line that extends in the radial direction with respect to the
axial line As will be referred to as a radial-direction axial line
Ar.
[0058] The blade portion 44 is formed so that a cross-section seen
in a direction in which the radial-direction axial line Ar extends
forms a blade shape. Meanwhile, in the example of FIG. 1 and FIG.
2, a state in which blade central lines Aw of the blade portions 44
are along the axial line As is shown. In the following description,
the constitution of the blade portion 44 will be described on the
basis of the positional relationship between the axial line As and
the blade portion 44 in the above-described state.
[0059] As shown in FIG. 1, the blade portion 44 forms substantially
a fan shape when seen on a cross-section including the axial line
As. In other words, the blade portion 44 is formed so that the
dimension in the width direction gradually decreases as the blade
portion runs from the outside toward the inside in the radial
direction with respect to the axial line As. An edge of the blade
portion 44 on the outside in the radial direction forms
substantially an arc shape so as to correspond to the spherical
surface shape of the inner circumferential surface of the suction
port 30. Furthermore, as shown in FIG. 2, the blade portion 44 has
a tapering cross-sectional shape that gradually tapers from the
outside toward the inside in the radial direction when seen in the
axial line As direction.
[0060] When the vane main bodies 42 constituted as described above
are respectively attached to the attachment portions 42S of the
suction casing 30A, as shown in an example of FIG. 2, the vane main
bodies 42 are stored on the inside of the suction casing 30A in the
radial direction and are then moved toward the outside in the
radial direction, thereby inserting the support portions 43 into
the attachment portions 42S. More specifically, the example of FIG.
2 shows an aspect of attaching a fifth vane main body 42 in a state
in which four vane main bodies 42 have been attached to the
attachment portions 42S respectively. Here, among the five vane
main bodies 42, the two vane main bodies from the front side in the
counterclockwise direction will be referred to as a first vane main
body 421 (first inlet guide vane) and a second vane main body 422
(second inlet guide vane) respectively. Furthermore, the vane main
body 42 to be newly attached will be referred to as a third vane
main body 423 (third inlet guide vane).
[0061] As shown in the same drawing, in a state in which other vane
main bodies 42 (the first vane main body 421 and the second vane
main body 422) have been already attached, there is a possibility
that an end portion of the third vane main body 423 on the inside
in the radial direction may interfere with the vane main bodies 42
that have been already provided. Therefore, in the case of
attaching the third vane main body 423, a method in which a portion
of the third vane main body 423 on the inside in the radial
direction is put into a gap between the first vane main body 421
and the second vane main body 422 which the third vane main body
423 faces and is then moved toward the outside in the radial
direction with respect to the axial line As, thereby being attached
to the attachment portion 42S is employed.
[0062] More specifically, as shown in FIG. 11, in a production
method of the centrifugal compressor 2 and an attachment method of
the inlet guide vane V according to the present embodiment, first,
the casing 28 and the plurality of vane main bodies 42 (the first
vane main body 421, the second vane main body 422, the third vane
main body 423, . . . ) are prepared (S1).
[0063] Next, the first vane main body 421 is attached (S2). In more
detail, the support portion 43 of the first vane main body 421 is
attached to the attachment portion 42S of the suction casing
30A.
[0064] Furthermore, the second vane main body 422 is attached to
the attachment portion 42S adjacent to the attachment portion 42S
to which the first vane main body 421 is attached in the
circumferential direction at an interval (S3).
[0065] Next, to another attachment portion 42S provide in a region
between the first vane main body 421 and the second vane main body
422 in the circumferential direction, the third vane main body 423
is attached (S4). More specifically, the third vane main body 423
is attached to an attachment portion 42S that faces the pair of
attachment portions 42S and 42S to which the first vane main body
421 and the second vane main body 422 are attached in the radial
direction of the axial line As. Furthermore, other vane main bodies
42 are attached to the corresponding attachment portions 42S
respectively as necessary. Therefore, the inlet guide vane V is
constituted.
[0066] Finally, to the casing main body 28A into which the rotary
shaft 29 and the impellers (the first impeller 21 and the second
impeller 22) have been already combined, the suction casing 30A is
attached (S6).
[0067] Therefore, all steps of the attachment method of the inlet
guide vane V and the production method of the centrifugal
compressor 2 according to the present embodiment are completed.
[0068] In order to employ the above-described attachment method,
the vane main body 42 (the blade portion 44) according to the
present embodiment has a cross-sectional shape as shown in FIG. 3
and FIG. 4 when seen in the As direction. The blade portion 44 has
a blade-like cross-sectional shape as a symmetric blade having a
linearly symmetric shape having the blade central line Aw as a
symmetric axis, and the thickness of the end portion on the inside
in the radial direction with respect to the axial line As is set to
be small.
[0069] When seen on a cross-section including the blade central
line Aw, a surface on one side of the blade central line Aw is used
as a pressure surface S1 which is a surface facing incoming fluid.
When seen on a cross-section including the blade central line Aw, a
surface on the other side of the blade central line Aw is used as a
suction surface S2 which is a surface that comes into contact with
fluid that flows away. That is, in the blade portion 44 as a
symmetric blade, each of the pressure surface S1 and the suction
surface S2 has a blade-shaped surface that runs along the surface
of an imaginary blade shape Pv as a symmetric blade. Meanwhile, in
the blade portion 44, the imaginary blade shape Pv is formed so as
to become smaller in a similar shape as the imaginary blade shape
runs from the outside in the radial direction to the inside in the
radial direction.
[0070] In an end portion on the outside in the radial direction
with respect to the axial line As, the support portion 43 is
integrally provided. In the following description, a region of the
blade portion 44 on the outside in the radial direction with
respect to the axial line As will be referred to as a base end-side
region A1. A region on a side opposite to the base end-side region
A1 in the radial direction will be referred to as a front end-side
region A2. Furthermore, the end portion of the blade portion 44 on
the front end side serves as a front end surface Sn which forms a
blade-shaped flat surface.
[0071] In the front end-side region A2 of the blade portion 44, a
surface (thin portion-forming surface St) which recedes toward the
inside of the imaginary blade shape Pv more than the surface of the
imaginary blade shape Pv is formed. Meanwhile, in the present
embodiment, an example in which the thin portion-forming surface St
is formed on the pressure surface S1 side of the blade portion 44
will be described. However, the thin portion-forming surface St may
be formed on the suction surface S2 side depending on the degree of
opening (an excess opening state or a squeezing state) preferred
during the operation of the compressor. In addition, the thin
portion-forming surfaces St may be formed on both the pressure
surface S1 and the suction surface S2.
[0072] In an end portion of the thin portion-forming surface St on
the outside in the radial direction, a connection surface Sc is
formed. The connection surface Sc is a curved surface which
connects a level difference between the blade-shaped surface
(imaginary blade shape Pv) and the thin portion-forming surface St.
Specifically, the connection surface Sc is a substantial arc-shaped
curved surface which connects an end portion of the base end-side
region A1 on the inside in the radial direction and the end portion
of the thin portion-forming surface St on the outside in the radial
direction which form the blade-shaped surface. The connection
surface Sc curves with respect to the blade-shaped surface so as to
sink toward the inside of the blade-shaped surface.
[0073] According to the above-described constitution, the thin
portion-forming surface St is formed in the front end-side region
A2 of the vane main body 42. Since the thin portion-forming surface
St recedes toward the inside of the imaginary blade shape Pv, the
thickness dimension of the blade portion 44 in the corresponding
region becomes thin. Therefore, when the plurality of vane main
bodies 42 is arrayed on the inner circumferential surface of the
casing (suction port) of the compressor in a state in which the
front ends thereof are gathered, it is possible to easily put a
vane main body 42 that is to be attached soon into a gap formed on
the inside in the radial direction of the vane main bodies 42 that
have been already attached.
[0074] Here, the thickness dimension of a region of the vane main
body 42 on the inside in the radial direction (the dimension of the
blade portion 44 in the circumferential direction with respect to
the axial line As in the case of being seen in the shaft axis As
direction) needs to be set to be smaller than a gap between a pair
of the vane main bodies 42 which faces each other in the suction
port.
[0075] On the other hand, from the viewpoint of improving the
performance and efficiency of the inlet guide vane V, the thickness
dimension of the vane main body 42 needs to be thick to a certain
extent. In other words, when the thickness of the vane main body 42
is too thin, there is a possibility that the performance and
efficiency of the inlet guide vane V may decrease.
[0076] However, in the present embodiment, the above-described
constitution is employed, and thus it is possible to satisfy the
performance and efficiency of the inlet guide vane V and the ease
of assembly.
[0077] Furthermore, in the present embodiment, the thin
portion-forming surface St is provided only in the front end-side
region A2. Therefore, compared with a case in which the thickness
is decreased throughout the entire blade portion 44 (the entire
region including the front end-side region A2 and the base end-side
region A1), it is possible to sufficiently ensure the performance
and efficiency of the inlet guide vane V.
[0078] Additionally, in the present embodiment, the imaginary blade
shape Pv becomes smaller in a similar shape as the blade-like
cross-sectional shape runs from the outside toward the inside in
the radial direction.
[0079] According to this constitution, in the region on the outside
in the radial direction in which the flow rate of fluid becomes
relatively faster, it is possible to relatively significantly
ensure the area of the imaginary blade shape Pv. Therefore, it is
possible to more effectively guide fluid and improve the efficiency
of the inlet guide vane V.
[0080] Additionally, in the vane main body 42 according to the
present embodiment, the pressure surface S1 has the connection
surface Sc that is configured to connect the level difference
between the blade-shaped surface and the thin portion-forming
surface St. According to this constitution, due to the formation of
the connection surface Sc, it is possible to decrease the
possibility that the flow of fluid along the pressure surface S1
may separate.
Second Embodiment
[0081] Subsequently, a second embodiment of the present invention
will be described with reference to FIG. 5 and FIG. 6. Meanwhile,
the same constitution as in the first embodiment will be given the
same reference sign and will not be described in detail.
[0082] In a vane main body 242 of the present embodiment, the thin
portion-forming surface St is formed along a surface that is formed
by the blade central line Aw of the imaginary blade shape Pv and
the radial-direction axial line Ar. That is, in the vane main body
242, the front end-side region A2 is formed to be relatively
thinner compared with the vane main body 42 in the first
embodiment.
[0083] According to this constitution, the same effects as the
first embodiment can be obtained, and furthermore, it is possible
to improve the ease of assembly of the inlet guide vane V while
maintaining the structural strength of the vane main body 42.
Third Embodiment
[0084] Next, a third embodiment of the present invention will be
described with reference to FIG. 7 and FIG. 8. Meanwhile, the same
constitution as in the first embodiment will be given the same
reference sign and will not be described in detail.
[0085] In a vane main body 342 according to the present embodiment,
the cross-sectional shape of the blade portion 44 is different from
that of the vane main body 42 of the first embodiment. That is, in
the vane main body 342, the thin portion-forming surface St is
formed so as to extend toward the suction surface S2 as the thin
portion-forming surface runs from an edge portion of the pressure
surface S1 on the front end surface Sn toward the outside in the
radial direction. That is, the thin portion-forming surface St
extends from a front end surface Sn side toward the outside in the
radial direction, then, intersects the radial-direction axial line
Ar, and runs into the back side. The front end surface Sn
symmetrically broadens toward both sides of the radial-direction
axial line Ar from the radial-direction axial line Ar. In other
words, in the vane main body 342, the front end-side region A2 is
formed to be relatively thicker compared with the vane main body 42
in the first embodiment.
[0086] According to this constitution, the same effects as the
first embodiment can be obtained, and furthermore, there is no case
in which the vane main body 42 becomes excessively thin due to the
provision of the thin portion-forming surface St. Therefore, it is
possible to more sufficiently ensure the structural strength of the
vane main body 42.
Fourth Embodiment
[0087] Next, a fourth embodiment of the present invention will be
described with reference to FIG. 9 and FIG. 10. In a vane main body
442 according to the present embodiment, the thin portion-forming
surface St is formed on the pressure surface S1 so as to be
sandwiched by the blade-shaped surface from both the inside in the
radial direction and the outside in the radial direction. In other
words, in the vane main body 442, the thin portion-forming surface
St is formed in a position which is in the middle of extension in
the radial direction on the pressure surface S1 and is far away
from both a front edge and a rear edge of the blade portion 44.
That is, the area of the thin portion-forming surface St is smaller
compared with those in the first embodiment to the third
embodiment.
[0088] According to the above-described constitution, the same
effects as the first embodiment can be obtained, and furthermore,
it is possible to suppress the size of the thin portion-forming
surface St being smaller compared with a case in which the thin
portion-forming surface St is formed throughout the entire region
including the end portion on the inside in the radial direction.
Therefore, it is possible to further decrease the separation of the
flow of fluid caused by the formation of the thin portion-forming
surface St.
[0089] Hitherto, the respective embodiments of the present
invention have been described with reference to the drawings. The
above-described embodiments are simply examples, and it is possible
to add a variety of modifications and corrections within the scope
of the gist of the present invention.
[0090] For example, in the respective embodiments described above,
the inlet guide vane V that is provided in the centrifugal
compressor 2 and the vane main body 42 that is used therein have
been described. However, the application subjects of the inlet
guide vane V and the vane main body 42 are not limited to
centrifugal compressors. Regarding the application subjects of the
inlet guide vane V and the vane main body 42, the inlet guide vane
and the vane main body can be applied to any kinds of machines as
long as the machines suction fluid thereinto and the suction amount
needs to be adjusted.
[0091] Furthermore, in the respective embodiments described above,
the two-stage-type centrifugal compressor 2 including two impellers
has been described. However, the number of stages of the
centrifugal compressor 2 is not limited thereto and may be three or
more.
[0092] Additionally, in the respective embodiments described above,
the descriptions have been made on the basis of the centrifugal
compressor 2 including the movable vanes 50 and the driving device
51. However, the centrifugal compressor 2 does not need to include
the movable vanes 50 and the driving device 51 at all times.
INDUSTRIAL APPLICABILITY
[0093] According to the inlet guide vane, it is possible to obtain
sufficient performance and ease of assembly.
REFERENCE SIGNS LIST
[0094] 2 CENTRIFUGAL COMPRESSOR [0095] 21 FIRST IMPELLER [0096] 22
SECOND IMPELLER [0097] 28 CASING [0098] 28A CASING MAIN BODY [0099]
29 ROTARY SHAFT [0100] 30 SUCTION PORT [0101] 30A SUCTION CASING
[0102] 31 SCROLL [0103] 32 INNER SPACE [0104] 33 RETURN FLOW
CHANNEL [0105] 34 SUCTION FLOW CHANNEL (INFLOW FLOW CHANNEL) [0106]
35 DIFFUSER [0107] 36 RETURN BEND PORTION [0108] 37 STRAIGHT FLOW
CHANNEL [0109] 38 RETURN VANE [0110] 40 MIDDLE SUCTION CHAMBER
[0111] 41 MIDDLE SUCTION PORT [0112] 42 VANE MAIN BODY [0113] 43
SUPPORT PORTION [0114] 44 BLADE PORTION [0115] 50 MOVABLE VANE
[0116] 51 DRIVING DEVICE [0117] 242 VANE MAIN BODY [0118] 342 VANE
MAIN BODY [0119] 421 FIRST VANE MAIN BODY [0120] 422 SECOND VANE
MAIN BODY [0121] 423 THIRD VANE MAIN BODY [0122] 442 VANE MAIN BODY
[0123] 42S ATTACHMENT PORTION [0124] A1 BASE END-SIDE REGION [0125]
A2 FRONT END-SIDE REGION [0126] Ar RADIAL-DIRECTION AXIAL LINE
[0127] As AXIAL LINE [0128] Aw BLADE CENTRAL LINE [0129] B BLADE
[0130] Pv IMAGINARY BLADE SHAPE [0131] S1 PRESSURE SURFACE [0132]
S2 SUCTION SURFACE [0133] Sc CONNECTION SURFACE [0134] Sn FRONT END
SURFACE [0135] St THIN PORTION-FORMING SURFACE
* * * * *