Patent Grant
10683872
The present invention relates to a bundle in a centrifugal compressor and a centrifugal compressor having the bundle.
For example, in order to compress a process gas in various plants, a centrifugal compressor is used. In the centrifugal compressor, the process gas entering a bundle from a suction port is compressed in a flow channel of an impeller by rotating the impeller along with a rotary shaft, and the process gas is ejected to the outside of the bundle from the discharge port.
Meanwhile, a centrifugal compressor bundle is formed by connecting a plurality of disk-shaped members (diaphragms) such as an intake casing, a discharge casing, and an impeller housing disclosed in PTL 1 in a direction of a rotary shaft. Each diaphragm is divided into two portions on the horizontal plane in a vertical direction.
[PTL 1] Japanese Unexamined Patent Application Publication No. 10-318191
In a centrifugal compressor, since a fluid is compressed from an intake side toward a discharge side so as to increase a pressure of the fluid, a pressing force is applied in a direction of an axis line of a rotary shaft from a discharge diaphragm (discharge side diaphragm) toward an intake diaphragm (intake side diaphragm). Here, in the intake diaphragm, a shape of a side to which a suction port is connected is different from a shape of a side to which the suction port is not connected. That is, since shapes of an upper-half portion and a lower-half portion which are divided into two portions are different from each other, if the pressing force is applied to the portions, and there is a difference in deformation amounts of the upper-half portion and the lower-half portion in the direction of the axis line. As a result, if the pressing force is applied to the intake diaphragm, the diaphragm is deformed to be bent with respect to the axis line, and an operation of the compressor is likely to be failed.
The present invention provides a centrifugal compressor bundle capable of decreasing a bending deformation and a centrifugal compressor having this bundle.
According to a first aspect of the present invention, there is provided a centrifugal compressor bundle, including: a bundle main body which includes a rotary shaft, an intake flow channel which rotatably supports an impeller which is fixed to the rotary shaft and rotates along with the rotary shaft about an axis line of the rotary shaft, introduces a fluid in a flow channel of the impeller, and is annularly formed about the axis line, and a discharge flow channel which discharges the fluid from a flow channel of the impeller and is annularly formed about the axis line, in which the bundle main body includes a plurality of diaphragms which are aligned in the direction of the axis line and are connected to each other, and among the plurality of diaphragms, an intake diaphragm in which the intake flow channel is formed includes an upper-half portion positioned on an upper side and a lower-half portion positioned on a lower side configured by dividing the intake diaphragm into two portions such as the upper side and the lower side in a state where a horizontal plane including the axis line is interposed therebetween, and the upper-half portion and the lower-half portion have the same rigidity as each other in the direction of the axis line.
According to the centrifugal compressor bundle, a pressing force is applied to the intake diaphragm of the bundle main body in the direction of the axis line from a rear stage side toward a front stage side by the compressed fluid. In this case, since the rigidities of the upper-half portion and the lower-half portion of the intake diaphragm are the same as each other in the direction of the axis line, the upper-half portion and the lower-half portion are deformed by the same amount as each other in the direction of the axis line. Accordingly, the intake diaphragm is not deformed to be inclined with respect to the horizontal plane including the axis line, and the intake diaphragm is deformed in only the direction of the axis line.
In addition, in the centrifugal compressor bundle according to a second aspect of the present invention, in the first aspect, areas of contact surfaces between the intake diaphragm and the diaphragms which are adjacent to the intake diaphragm on the discharge flow channel side in the direction of the axis line may be the same as each other in the upper-half portion and the lower-half portion.
In this way, since the area of the contact surface with the adjacent diaphragm is the same in the upper-half portion and the lower-half portion, when the pressing force is applied to the intake diaphragm in the direction of the axis line by the compressed fluid, surface pressures on the contact surfaces of the upper-half portion and the lower-half portion can be the same as each other. Accordingly, since the intake diaphragm is deformed to be equally compressed in the direction of the axis line by the pressing force, the intake diaphragm is not deformed to be inclined with respect to the horizontal plane including the axis line, and the intake diaphragm is deformed in only the direction of the axis line.
In addition, in the centrifugal compressor bundle according to a third aspect of the present invention, in the first or second aspect, an inlet of the intake flow channel may be formed in the upper-half portion, the upper-half portion may include a first straightening plate which is provided in the inlet and extends in the radial direction, and a pair of second straightening plates which is disposed on both sides in a peripheral direction of the rotary shaft with respect to the first straightening plate and is provided to be separated from the first straightening plate toward the inside in the radial direction, and surfaces of the first straightening plate and the second straightening plate facing the direction of the axis line may configure a portion of the contact surface.
In this way, since the first straightening plate and the second straightening plate configure the contact surface with a head adjacent to the intake diaphragm in the direction of the axis line, it is possible to equalize deformation amounts of the upper-half portion and the lower-half portion without disturbing the flow of the fluid entering from the suction port to the intake flow channel.
In addition, in the centrifugal compressor bundle according to a fourth aspect of the present invention, in the third aspect, the contact surfaces of the intake diaphragm may be formed at positions separated by 90° around the axis line based on the position of the first straightening plate.
In this way, since the contact surfaces are formed at the positions every 90° in the peripheral direction, it is possible to approximately equally distribute the pressing force from the compressed fluid in the peripheral direction, and deformation of the upper-half portion and the lower-half portion can be generated in the direction of the axis line. Accordingly, it is possible to prevent the deformation of the intake diaphragm which is inclined with respect to the horizontal plane including the axis line, that is, it is possible to prevent generation of bending deformation.
In addition, according to a five aspect of the present invention, there is provided a centrifugal compressor, including: the centrifugal compressor bundle according to any one of the first to fourth aspects; a rotary shaft which is supported by the bundle so as to be rotatable with respect to the bundle; and an impeller which is fixed to the rotary shaft and rotates in the bundle main body along with the rotary shaft.
According to the centrifugal compressor, since the centrifugal compressor includes the bundle, when the pressing force is applied to the intake diaphragm of the bundle main body in the direction of the axis line from the rear stage side toward the front stage side by the compressed fluid, the upper-half portion and the lower-half portion are deformed by the same amount as each other in the direction of the axis line. Accordingly, the intake diaphragm is not deformed to be inclined with respect to the horizontal plane including the axis line, and the intake diaphragm is deformed in only the direction of the axis line.
According to the centrifugal compressor bundle and the centrifugal compressor, since the rigidities of the upper-half portion and the lower-half portion of the intake diaphragm are the same as each other in the direction of the axis line, it is possible to prevent the bending deformation of the bundle main body.
Hereinafter, a centrifugal compressor 1 of an embodiment of the present invention will be described.
As shown in
The centrifugal compressor 1 includes a rotary shaft which rotates about the axis line O, a plurality of impellers 3 which are fixed to the rotary shaft 2, a bundle 5 which rotatably supports the rotary shaft 2 and the impellers 3, and an outside casing 6 which covers the bundle 5 from the outer peripheral side.
The rotary shaft 2 is formed in a columnar shape about the axis line O.
The plurality of impellers 3 (six impellers in the present embodiment) are arranged to be separated from each other in the direction of the axis line O.
Each of the impellers 3 has an approximately disk shape, is fitted to the rotary shaft 2, and is rotatable about the axis line O along with the rotary shaft 2. In addition, a flow channel FC through which a process gas G (fluid) can flow is formed in each impeller 3.
In three impellers 3 which are disposed on one side (a left side toward a paper surface of
In three-stage impellers 3 which are disposed on the other side (the right side toward the paper surface of
The bundle 5 includes a plurality of diaphragms 11 which are formed in disk shapes about the axis line O and a bundle main body 10 having heads 12.
The plurality of diaphragms 11 and the heads 12 are connected in the direction of the axis line O by bolts (not shown) to form the bundle main body 10. That is, the bundle main body 10 has a structure which is divided into a plurality of portions on a cross-section orthogonal to the axis line O.
A pair of heads 12 is provided such that the plurality of diaphragms 11 are interposed between both ends of the axis line O in the direction of the axis line O, and each head is a member which is formed in a disk shape about the axis line O.
Each diaphragm 11 has a structure which is divided into two portions in a vertical direction on a horizontal plane including the axis line O.
In the bundle main body 10, the diaphragms 11 of one end portion and the other end portion in the direction of the axis line O become intake diaphragms 11A. In each intake diaphragm 11A, an intake flow channel FC1 which is annually formed about the axis line O and through which the process gas G can be introduced to the flow channel FC of the impeller 3 is formed. In the intake flow channel FC1, an intake flow channel opening OP1 (inlet) is formed, which is open to the outside in the radial direction on a portion (the upper portion in the present embodiment) in the peripheral direction in the intake diaphragm 11A.
The intake diaphragm 11A is divided in the vertical direction, and includes an upper-half portion 20 which is formed in a semi-disk shape and is positioned on the upper side, and a lower-half portion 30 which is formed in a semi-disk shape and is positioned on the lower side. The details of the upper-half portion 20 and the lower-half portion 30 will be described later.
In the bundle main body 10, the diaphragm 11 which covers the initial stage (first stage) impeller 3(3A) in each of the first impeller group 4A and the second impeller group 4B becomes a first intermediate diaphragm 11B. In the first intermediate diaphragm 11B, a return flow channel FC3 which communicates with an outlet of the flow channel FC of the initial stage impeller 3 (3A) and an inlet of a flow channel FC of an intermediate stage (second stage) impeller 3 (3B) is formed.
Similarly, in the bundle main body 10, the diaphragm which covers the intermediate stage (second stage) impeller 3(3B) in each of the first impeller group 4A and the second impeller group 4B becomes a second intermediate diaphragm 11C. In the second intermediate diaphragm 11C, a return flow channel FC4 which communicates with an outlet of the flow channel FC of the intermediate stage impeller 3 (3B) and an inlet of the flow channel FC of a final stage (third stage) impeller 3 (3C) is formed.
In the second intermediate diaphragm 11C, a portion of a discharge flow channel FC2 which is annularly formed about the axis line O and can discharge the process gas G from the flow channel FC of the impeller 3 is formed.
In the bundle main body 10, the diaphragm 11 which covers the final stage (third stage) impeller 3 (3C) in each of the first impeller group 4A and the second impeller group 4B becomes a discharge diaphragm 11D. In the discharge diaphragm 11D, a portion of the remainder of the discharge flow channel FC2 which is annularly formed about the axis line O and can discharge the process gas G from the flow channel FC of the impeller 3 is formed.
That is, the discharge flow channel FC2 is formed by the discharge diaphragm 11D and the second intermediate diaphragm 11C. In the discharge flow channel FC2, a discharge flow channel opening OP2 (outlet) is formed, which is open to the outside in the radial direction at a portion (the upper portion in the present embodiment) of the second intermediate diaphragm 11C and the discharge diaphragm 11D in the peripheral direction.
In the bundle main body 10, the diaphragm 11 which is disposed at a position interposed between the first impeller group 4A and the second impeller group 4B becomes a diaphragm 11E between final stages. In the diaphragm 11E between final stages, a seal device 15 which seals the flow of the process gas G between the first impeller group 4A and the second impeller group 4B is provided on the outer peripheral side of the rotary shaft 2.
The outside casing 6 is formed in a cylindrical shape, covers the bundle main body 10 from the outer peripheral side, and fixes the bundle main body 10. A pair of suction ports 6a which extends in the radial direction, is open to the outside, and communicates with the intake flow channel opening OP1 is formed in the outside casing 6. In addition, a pair of discharge ports 6b which extends in the radial direction, is open to the outside, and communicates with the discharge flow channel opening OP2 is formed in the outside casing 6.
In the present embodiment, the suction ports 6a and the discharge ports 6b are formed on the upper portion of the outside casing 6 so as to extend upward.
Next, the details of the upper-half portion 20 and the lower-half portion 30 of the intake diaphragm 11A will be described with reference to
The upper-half portion 20 includes a main body portion 22 which is formed in a semi-disk shape about the axis line O and a first straightening plate 23, second straightening plates 24, and outer wall portions 25 which protrude from the main body portion 22 toward the head 12 side in the direction of the axis line O.
A semicircular opening 20a which surrounds the rotary shaft 2 from the outer peripheral side is formed at the position inside the main body portion 22 in the radial direction.
The first straightening plate 23 extends in the radial direction (in the vertical direction) from the intake flow channel opening OP1 toward the inside in the radial direction, protrudes from the main body portion 22 toward the head 12 side in the direction of the axis line O, and is formed in a vane shape when viewed in the direction of the axis line O.
That is, after the thickness dimension of the first straightening plate 23 in the peripheral direction gradually increases toward the inside in the radial direction, the thickness dimension gradually decreases.
In the first straightening plate 23, an approximately half portion 23a on the outside in the radial direction of a surface facing the head 12 side in the direction of the axis line O becomes a portion of a contact surface 40 with the head 12 adjacent to the intake diaphragm 11A in the direction of the axis line O.
The second straightening plates 24 are disposed to be separated from the first straightening plate 23, and are disposed to be inclined so as to be separated from the first straightening plate 23 toward the inside in the radial direction at each of both sides in the peripheral direction with respect to the first straightening plate 23.
That is, the process gas G from the suction port 6a can flow through a portion between the second straightening plate 24 and the first straightening plate 23.
Each second straightening plate 24 protrudes from the main body portion 22 toward the head 12 side in the direction of the axis line O, and is formed in a rectangular shape when viewed in the direction of the axis line O.
In the second straightening plate 24, an approximately half portion 24a on the outside in the radial direction of a surface facing the head 12 side in the direction of the axis line O becomes a portion of a contact surface 40 with the head 12 adjacent to the intake diaphragm 11A.
A pair of outer wall portions 25 is provided to be curved along the outer peripheral surface of the main body portion 22 and forms the outer wall of the intake flow channel FC1. In addition, the pair of outer wall portions is formed to the position separated from the second straightening plate 24 in the peripheral direction on the upper portion. That is, the process gas G can flow through a portion between the second straightening plates 24.
Since the thickness dimension of the outer wall portion 25 in the radial direction gradually increases downward, a flow channel area of the intake flow channel FC1 gradually decreases downward.
In the surface of the outer wall portion 25 facing the discharge flow channel FC2 side in the direction of the axis line O, only a portion 25a along the peripheral surface of the main body portion 22 becomes a portion of the contact surface 40 with the head 12. The width dimension of the portion 25a along the peripheral surface in the radial direction is constant in the peripheral direction.
The lower-half portion 30 includes a main body portion 32 which is formed in a semi-disk shape about the axis line O and an outer wall portion 35 which protrudes from the main body portion 32 toward the head 12 side in the direction of the axis line O.
In the main body portion 32, a semicircular opening 30a which surrounds the rotary shaft 2 from the outer peripheral side at the position on the inside in the radial direction is formed. A circular opening 11Aa into which the rotary shaft 2 can be inserted is formed by the opening 30a and the opening 20a in the main body portion 22 of the upper-half portion 20.
The outer wall portion 35 is curved along the outer peripheral surface of the main body portion 32, is provided on the entire region of the outer peripheral surface of the main body portion 32, and forms the outer wall of the intake flow channel FC1.
Since the thickness dimension in the radial direction of the outer wall portion 35 gradually increases downward, the flow channel area of the intake flow channel FC1 gradually decreases downward.
The thickness of the upper end portion of the outer wall portion 35 coincides with the thickness of the lower end portion of the outer wall portion 25 of the upper-half portion 20, and the outer wall portion 35 of the lower-half portion 30 and the outer wall portion 25 of the upper-half portion 20 are smoothly connected to each other without steps.
In addition, in the surface of the outer wall portion 35 facing the head 12 side in the direction of the axis line O, only a portion of an annular portion 35a of a half circumference about the axis line O along the outer peripheral surface of the main body portion 32 becomes a portion of the contact surface 40 with the head 12.
More specifically, as the contact surface 40 in the lower-half portion 30, a pair of curved surfaces 41 which is formed from the upper end portion of the lower-half portion 30 to the intermediate position in the vertical direction, and an approximately rectangular lower end surface 42 which is formed on the lower end portion to be separated from the curved surfaces 41 in the peripheral direction are formed on the lower-half portion 30.
In the curved surfaces 41 and the lower end surface 42, the outer wall portion 35 is formed to be recessed in the direction of the axis line O between the curved surface 41 and the lower end surface 42.
The width dimensions of the curved surfaces 41 and the lower end surface 42 in the radial direction are the same as the width dimensions in the radial direction of the portions 25a along the outer peripheral surface in the outer wall portion 25 of the upper-half portion 20, and the width dimensions are constant in the peripheral direction.
Moreover, in the present embodiment, the upper-half portion 20 and the lower-half portion 30 are formed of the same material, and rigidities of the upper-half portion 20 and the lower-half portion 30 are the same as each other.
In addition, the area of the contact surface 40 of the upper-half portion 20 is the same as the area of the contact surface 40 of the lower-half portion 30. Moreover, in the present embodiment, the contact surfaces 40 are formed at least positions separated by 90° around the axis line O based on the position of the first straightening plate 23.
According to the above-described centrifugal compressor 1, a force is generated in the direction of the axis line O from the front stage side (discharge diaphragm 11D side) toward the rear stage side (intake diaphragm 11A side) by the compressed process gas G, and this force becomes a pressing force and is applied to the intake diaphragm 11A.
In this case, since the rigidities of the upper-half portion 20 and the lower-half portion 30 of the intake diaphragm 11A are the same as each other in the direction of the axis line O, the upper-half portion 20 and the lower-half portion 30 are deformed by the same amount as each other in the direction of the axis line O. Accordingly, the intake diaphragm 11A is not deformed to be inclined with respect to the horizontal plane including the axis line O, and the intake diaphragm 11A is deformed in only the direction of the axis line O. Accordingly, it is possible to prevent the intake diaphragm 11A from being inclined to the horizontal plane and bending-deformed.
In addition, since the area of the contact surface of the upper-half portion 20 and the area of the contact surface 40 of the lower-half portion 30 are the same as each other, when the pressing force is applied to the intake diaphragm 11A in the direction of the axis line O by the compressed process gas G, surface pressures on the contact surfaces 40 of the upper-half portion 20 and the lower-half portion 30 can be the same as each other.
Accordingly, since the intake diaphragm 11A is deformed to be equally compressed in the direction of the axis line O by the pressing force, it is possible to further prevent the bending deformation of the intake diaphragm 11A.
In addition, since the first straightening plate 23 and the second straightening plates 24 configure the contact surface 40 with the head 12, it is possible to equalize deformation amounts of the upper-half portion 20 and the lower-half portion 30 without disturbing the flow of the process gas G entering from the suction port 6a to the intake flow channel FC1.
Particularly, in the present embodiment, since the first straightening plate 23 is formed in a vane shape, it is possible to introduce the process gas G into the intake flow channel FC1 without separating the process gas G from the suction port 6a.
Moreover, in the intake diaphragm 11A, since the contact surfaces 40 are formed at the positions at least every 90° in the peripheral direction, it is possible to approximately equally distribute the pressing force in the peripheral direction, and deformation of the upper-half portion 20 and the lower-half portion 30 due to the pressing force can be generated in the direction of the axis line O. Accordingly, it is possible to prevent generation of the bending deformation in the intake diaphragm 11A.
[Example]
Here, with reference to
In an intake diaphragm 51A shown in
In the upper-half portion 52, the contact surface 40 with the head 12 is configured of approximately the half portion 23a (the portion similar to that of the above-described embodiment) on the outside in the radial direction in the surface of the first straightening plate facing the head 12 side in the direction of the axis line O, and the portion 25a along the outer peripheral surface of the main body portion 22 in the surface of the outer wall portion 25 facing the head 12 side in the direction of the axis line O.
In addition, in the lower-half portion 53, the contact surface 40 is configured of the entire region of an annular portion 53a of a half circumference about the axis line O along the outer peripheral surface of the main body portion 32 in the surface of the outer wall portion facing the head 12 side in the direction of the axis line O. The width dimension in the radial direction of the annular portion 53a of the half circumference is constant in the peripheral direction.
In the intake diaphragm 51A, since the deformation amount of the upper-half portion 52 in the direction of the axis line O was large and the deformation amount of the lower-half portion 53 in the direction of the axis line O was small, the bundle main body 10 was bending-deformed such that the upper-half portion 52 was inclined to the head 12 side with respect to the axis line O.
Accordingly, as shown in
As result, the deformation amount of the upper-half portion 62 was small in the direction of the axis line O, but a difference between the deformation amount of the lower-half portion 53 in the direction of the axis line O was large, and the bundle main body 10 was still bending-deformed such that the upper-half portion 62 was inclined to the head 12 side with respect to the axis line O.
In addition, as shown in
As a result, the deformation amount of the lower-half portion 73 in the direction of the axis line O was large, and the bundle main body 10 was bending-deformed such that the lower-half portion 73 was inclined to the head 12 side.
Accordingly, in the intake diaphragm 81A shown in
Accordingly, finally, in the intake diaphragm 11A of the above-described embodiment shown in
As a result, the contact surface pressure of the approximately half portion 64a of on the outside of the second straightening plate 24 in the radial direction was equal or less than the allowable stress, the deformation amounts of the upper-half portion 20 and the lower-half portion 30 in the direction of the axis line O could be the same as each other, and it was possible to prevent the bending deformation of the bundle main body 10.
Hereinbefore, the embodiment of the present invention is described with reference to the drawings, components in each embodiment, a combination thereof, and the like are examples, and addition, omission, replacement, and other modifications of configurations can be applied within a scope which does not depart from the gist of the present invention. In addition, the present invention is not limited by the embodiment and is limited by only claims.
For example, the first straightening plate 23 may not be formed in a vane shape when viewed in the direction of the axis line O, and may be formed in a rectangular shape similarly to the second straightening plate 24.
In addition, similarly to the first straightening plate 23, the second straightening plate 24 may be formed in a vane shape when viewed in the direction of the axis line O.
In addition, the number of the first straightening plates 23 and the number of the second straightening plates 24 are not limited.
In the above-described centrifugal compressor bundle and the centrifugal compressor, since the rigidities of the upper-half portion and the lower-half portion of the intake diaphragm in the direction of the axis line are the same as each other, it is possible to prevent the bending deformation of the bundle main body.
1: centrifugal compressor
2: rotary shaft
3, 3A, 3B: impeller
4: impeller group
4A: first impeller group
4B: second impeller group
5: bundle
6: outside casing
6
a: suction port
6
b: discharge port
10: bundle main body
11: diaphragm
11A, 51A, 61A, 71A, 81A: intake diaphragm
11Aa: opening
11B: first intermediate diaphragm
11C: second intermediate diaphragm
11D: discharge diaphragm
11E: diaphragm between final stages
12: head
15: seal device
20, 52, 62: upper-half portion
20
a: opening
22: main body portion
23: first straightening plate
24, 64: second straightening plate
25: outer wall portion
30, 53, 73, 83: lower-half portion
30
a: opening
32: main body portion
35: outer wall portion
40: contact surface
41, 75: curved surface
42, 85: lower end surface
FC: flow channel
FC1: intake flow channel
OP1: intake flow channel opening
FC2: discharge flow channel
OP2: discharge flow channel opening
FC3: return flow channel
FC4: return flow channel
O: axis line
G: process gas (fluid)
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2015/052172 | 1/27/2015 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2016/120990 | 8/4/2016 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 3051090 | Zumbusch | Aug 1962 | A |
| 3733145 | Kaplansky et al. | May 1973 | A |
| 7513735 | Sarri | Apr 2009 | B2 |
| 7559742 | Inoue | Jul 2009 | B2 |
| 9163643 | Masutani | Oct 2015 | B2 |
| 20160017888 | Nakaniwa et al. | Jan 2016 | A1 |
| Number | Date | Country |
|---|---|---|
| 201606307 | Oct 2010 | CN |
| 196 54 840 | Jun 1998 | DE |
| 62-59796 | Apr 1987 | JP |
| 6-83988 | Dec 1994 | JP |
| 10-318191 | Dec 1998 | JP |
| 2014-185523 | Oct 2014 | JP |
| WO 2005045251 | May 2005 | WO |
| Entry |
|---|
| Written Opinion of the International Searching Authority and International Search Report (forms PCT/ISA/237 and PCT/ISA/210), dated Apr. 28, 2015, for International Application No. PCT/JP2015/052172, with English translations. |
| Number | Date | Country | |
|---|---|---|---|
| 20180010615 A1 | Jan 2018 | US |
