Compressor

Abstract

To provide a compressor which achieves further reduction of noise.SOLUTION: A compressor includes: a rotary shaft which rotates around an axis; an impeller which rotates with the rotary shaft to pump a fluid from one axial side to the radial outer side; a casing which encloses the rotary shaft and the impeller and is formed with an outlet passage for guiding the fluid pumped by the impeller; and an acoustic liner which is provided so as to face the interior of the outlet passage in the casing. The acoustic liner has: multiple open hole parts which are arranged at an interval; and an acoustic space communicating with the open hole parts and provided independently for each open hole part.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a compressor.

Background Art

[0002] In turbomachinery including a compressor, noise is generated as rotating components rotate. If such noise propagates to stationary components, it may cause structural damage to the stationary components. Therefore, for the purpose of noise prevention, a configuration has been proposed in which an acoustic liner is provided in the outlet flow path of the compressor (Patent Document 1 below). This acoustic liner has an introduction hole that opens toward the outlet flow path and an acoustic space connected to the downstream side of the introduction hole. A plurality of introduction holes are formed for one acoustic space.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in the outlet flow path of the compressor, the static pressure increases toward the downstream side. For this reason, in the acoustic liner, a leakage flow occurs from the introduction holes located relatively downstream to the acoustic holes on the upstream side through the acoustic space. As a result, fluid may not flow properly into the acoustic space, which may affect the characteristics as an acoustic liner.

[0005] The present disclosure has been made to solve the above problems, and an object thereof is to provide a compressor with further reduced noise.

Means for Solving the Problems

[0006] The compressor according to the present disclosure includes a rotating shaft that rotates around an axis, an impeller that rotates together with the rotating shaft to pump fluid from one side in the axial direction toward the radially outer side, a casing that surrounds the rotating shaft and the impeller and forms an outlet flow path for guiding the fluid pumped from the impeller, and an acoustic liner provided so as to face the inside of the outlet flow path in the casing. The acoustic liner has a plurality of apertures arranged at intervals from each other, and an acoustic space communicating with the apertures and provided independently for each aperture. The compressor further includes a plurality of diffuser vanes provided in the outlet flow path, extending from the radially inner side to the outer side with respect to the axis toward the front side in the rotation direction of the impeller, and arranged at intervals in the circumferential direction. When viewed from the axial direction, on the front side in the rotation direction of each diffuser vane, it is formed by a plurality of the apertures arranged over a direction orthogonal to the extending direction of the diffuser vane, and a plurality of In a row are formed, provided at intervals in the extending direction of the diffuser vane, and Group of apertures are formed. The acoustic spaces communicating with the apertures belonging to the same group of the apertures communicate with each other, and the acoustic spaces communicating with the apertures belonging to different groups of the apertures do not communicate with each other. The compressor according to the present disclosure includes a rotating shaft that rotates around an axis, an impeller that rotates together with the rotating shaft to pump fluid from one side in the axial direction toward the radially outer side, a casing that surrounds the rotating shaft and the impeller and forms an outlet flow path for guiding the fluid pumped from the impeller, and an acoustic liner provided so as to face the inside of the outlet flow path in the casing. The acoustic liner has a plurality of apertures arranged at intervals from each other, and an acoustic space communicating with the apertures and provided independently for each aperture. When viewed from the axial direction, it is formed by a plurality of the apertures arranged in an annular shape centered on the axis, and a plurality of aperture groups are formed, provided at intervals in the radial direction of the axis, and In a row are formed. The acoustic spaces communicating with the apertures belonging to the same group of the apertures communicate with each other, and the acoustic spaces communicating with the apertures belonging to different groups of the apertures do not communicate with each other.

Advantages of the Invention

[0007] According to the present disclosure, a compressor with further reduced noise can be provided.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Mode for Carrying Out the Invention

[0009] <First Embodiment> (Configuration of Compressor) Hereinafter, the compressor 100 according to the first embodiment of the present disclosure will be described with reference to FIGS. 1 to 3. As shown in FIG. 1, the compressor 100 includes a rotating shaft 1, an impeller 2, a casing 3, diffuser vanes 4, and an acoustic liner 5.

[0010] The rotating shaft 1 extends along the axis O and is rotatable about the axis O. An impeller 2 is fixed to the outer peripheral surface of the rotating shaft 1. The impeller 2 has a disk 21 and a plurality of blades 22. The disk 21 has a disk shape centered on the axis O. The outer peripheral surface (main surface 21A) of the disk 21 has a curved surface shape that curves from the inner side in the radial direction to the outer side from one side in the direction of the axis O to the other side.

[0011] A plurality of blades 22 are provided on the main surface 21A at intervals in the circumferential direction. Although not shown in detail, each blade 22 curves from the front side in the rotation direction of the rotating shaft 1 to the rear side as it goes from the inner side in the radial direction to the outer side. The impeller 2 rotates together with the rotating shaft 1 to pump the fluid introduced from one side in the direction of the axis O toward the outer side in the radial direction.

[0012] The casing 3 surrounds these rotating shafts 1 and the impeller 2 from the outer peripheral side. Inside the casing 3, a compression flow path P that houses the impeller 2 and compresses the fluid led from the outside, and an outlet flow path F connected to the radially outer side of the compression flow path P are formed. The compression flow path P gradually increases in diameter from one side in the direction of the axis O toward the other side so as to correspond to the outer shape of the impeller 2. The outlet flow path F is connected to the outlet on the radially outer side of the compression flow path P.

[0013] The outlet flow path F has a diffuser flow path F1 and an outlet scroll F2. The diffuser flow path F1 is provided to recover the static pressure of the fluid led from the compression flow path P. The diffuser flow path F1 forms an annular shape extending radially outward from the outlet of the compression flow path P. In a cross-sectional view including the axis O, the flow path width of the diffuser flow path F1 is constant over the entire extending direction. A plurality of diffuser vanes 4 are provided in the diffuser flow path F1. As shown in FIG. 2, these diffuser vanes 4 are arranged in a plurality with intervals in the circumferential direction. Further, each diffuser vane 4 extends toward the front side in the rotation direction of the impeller 2 from the radially inner side toward the outer side with respect to the axis O. That is, the diffuser vane 4 is inclined with respect to the radial direction with respect to the axis O.

[0014] As shown in FIG. 1, an outlet scroll F2 is connected to the outlet on the radially outer side of the diffuser flow path F1. The outlet scroll F2 forms a spiral shape extending in the circumferential direction of the axis O. The outlet scroll F2 has a circular flow path cross-section. An exhaust hole for leading the high-pressure fluid to the outside is formed in a part of the outlet scroll F2 (not shown).

[0015] (Configuration of acoustic liner) On the wall surface on the other side in the direction of the axis O in the above-described diffuser flow path F1, an acoustic liner 5 is provided. The acoustic liner 5 is provided to absorb and attenuate the noise caused by the fluid flowing through the diffuser flow path F1. The acoustic liner 5 is embedded in this wall surface so as to face the diffuser flow path F1. More specifically, in the present embodiment, the acoustic liner 5 is provided on the surface facing one side in the direction of the axis O in the diffuser flow path F1. Note that the acoustic liner 5 may also be provided on the surface facing the other side in the direction of the axis O in the diffuser flow path F1. Further, it is also possible to adopt a configuration in which the acoustic liner 5 is provided only on the surface facing the other side in the direction of the axis O. The acoustic liner 5 has an annular shape centered on the axis O.

[0016] As shown in FIG. 3, the acoustic liner 5 has a plurality of apertures 51 and a plurality of acoustic spaces 52. The apertures 51 are arranged at intervals along the wall surface of the diffuser flow path F1. Further, the apertures 51 are formed on the wall surface with a uniform aperture ratio (the number of apertures per unit area is constant). These apertures 51 communicate with the acoustic spaces 52. The acoustic spaces 52 are provided independently for each of the respective apertures 51. The apertures 51 have a diameter dimension smaller than that of the acoustic spaces 52. Thereby, the apertures 51 and the acoustic spaces 52 respectively form Helmholtz resonators. Further, as shown in FIG. 2, in the present embodiment, as an example, the apertures 51 are arranged in a direction orthogonal to the diffuser vanes 4 on the rear side in the rotational direction, and a plurality of such rows are arranged in the radial direction.

[0017] As shown in FIG. 3, the acoustic liner 5 is formed by laminating three plate materials. Specifically, the acoustic liner 5 includes a first plate material 10 in which a first hole 61 as an opening 51 is formed in advance, a second plate material 11 in which a second hole 62 as an acoustic space 52 is formed in advance, and a solid third plate material 12 in which no hole is formed. The positions of the first hole 61 and the second hole 62 coincide with each other. By laminating the first plate material 10, the second plate material 11, and the third plate material 12 in this order, the acoustic liner 5 having the independent acoustic space 52 as described above is formed. Such an acoustic liner 5 is embedded in a recess formed in the wall surface of the diffuser flow path F1. Note that it is also possible to form the acoustic liner 5 by embedding only the first plate material 10 and the second plate material 11 in the recess of the wall surface without providing the third plate material 12.

[0018] (Function and effect) Next, the operation of the compressor 100 will be described. When operating the compressor 100, first, the rotating shaft 1 is rotated around the axis O by an external drive source. Along with the rotation of the rotating shaft 1, the impeller 2 also rotates, and thereby an external fluid is guided into the compression flow path P. The fluid guided by the blades 22 of the impeller 2 in the compression flow path P is compressed by centrifugal force and becomes a high-pressure state. The flow path in this high-pressure state is taken out to the outside through the diffuser flow path F1 and the outlet scroll F2.

[0019] Here, in the compressor 100 as described above, noise is generated along with the rotation of the impeller 2. Among such noise, in particular, the noise called NZ noise is likely to resonate with each part of the compressor 100, so it is important to reduce and suppress it. The NZ noise is noise (discrete frequency noise) having a frequency based on the value obtained by integrating the number of blades Z of the impeller 2 (that is, the number of blades 22) and the rotational speed N of the rotating shaft 1.

[0020] For the purpose of reducing and suppressing such NZ noise, in this embodiment, an acoustic liner 5 is provided in the diffuser flow path F1. The sound wave introduced into the acoustic space 52 through the opening 51 is attenuated in the acoustic space 52. Thereby, it is possible to suppress the leakage of noise to the outside.

[0021] Incidentally, in the diffuser flow path F1 as described above, since the static pressure recovery progresses more toward the outer side in the radial direction, the pressure of the fluid is high. Also, in the direction connecting the diffuser vanes 4 to each other (the rotation direction of the impeller 2), the pressure of the fluid becomes higher toward the front side in the rotation direction. For this reason, for example, when a single acoustic space 52 is formed with respect to a plurality of apertures 51, there is a possibility that a leakage flow of the fluid may occur through the acoustic space 52 based on the imbalance of the above pressure distribution. That is, a leakage flow occurs from the aperture 51 on the high-pressure side toward the aperture 51 on the low-pressure side through the acoustic space 52. When such a leakage flow occurs, the fluid does not appropriately flow into the acoustic space 52, which may affect the characteristics as the acoustic liner 5.

[0022] Therefore, in the present embodiment, independent acoustic spaces 52 are formed for each of the apertures 51 as described above. According to the above configuration, since the acoustic spaces 52 are provided independently for each aperture 51, it is possible to reduce the possibility that a leakage flow occurs from the high-pressure region on the downstream side of the diffuser flow path F1 toward the low-pressure region on the upstream side through the acoustic space 52. As a result, the acoustic characteristics of the acoustic liner 5 can be improved.

[0023] Also, according to the above configuration, the acoustic liner 5 can be easily configured with high machining accuracy only by laminating the first plate member 10 in which the first hole portion 61 is formed in advance and the second plate member 11 in which the second hole portion 62 is formed. Thereby, the processing cost and the maintenance cost can be reduced.

[0024] The first embodiment of the present disclosure has been described above. Note that various changes and modifications can be made to the above configuration without departing from the gist of the present disclosure. For example, in the first embodiment above, an example in which the apertures 51 are formed with a uniform aperture ratio over the entire surface of the acoustic liner 5 has been described. However, since the above NZ sound is prominent in the region closer to the upstream side by the impeller 2, it is also possible to configure such that the aperture ratio of the apertures 51 decreases as it goes toward the downstream side (that is, the radially outer side) of the diffuser flow path F1.

[0025] <Second Embodiment> Next, a second embodiment of the present disclosure will be described with reference to FIG. 4. Note that the same components as those in the first embodiment above are denoted by the same reference numerals, and detailed descriptions thereof are omitted. As shown in FIG. 4, in the present embodiment, the acoustic spaces 52 communicate with each other in a region where the static pressures in the outlet flow path F (diffuser flow path F1) are equal to each other. More specifically, in a region extending in a direction orthogonal to the negative pressure surface of the diffuser vane 4 (the surface facing the front side in the rotation direction of the impeller 2), the acoustic spaces 52 communicate with each other. Here, the “orthogonal” referred to herein means a substantially orthogonal state, and design tolerances and manufacturing errors are allowed.

[0026] Here, in a region where the static pressures in the diffuser flow path F1 are equal to each other, leakage flow through the acoustic space 52 hardly occurs. Therefore, by communicating the acoustic spaces 52 with each other for each such region, a large volume as the acoustic space 52 can be secured. Thereby, the acoustic characteristics of the acoustic liner can be further improved.

[0027] As a specific example, the static pressure is constant in a region extending in a direction orthogonal to the diffuser vane 4, and leakage flow through the acoustic space hardly occurs. Therefore, by adopting the above configuration, a large volume as the acoustic space 52 can be secured. Thereby, the acoustic characteristics of the acoustic liner can be further improved.

[0028] The second embodiment of the present disclosure has been described above. Various changes and modifications can be made to the above configuration without departing from the gist of the present disclosure. For example, when adopting a configuration without the diffuser vane 4 as the compressor 100, as shown in FIG. 5, the acoustic space 52 of the acoustic liner 5 is divided into a plurality (for example, three) of annular regions 52c, 52d, 52e arranged radially around the axis O, and a configuration can be adopted in which the acoustic spaces 52 communicate with each other for each region.

[0029] According to the above configuration, in a compressor without the diffuser vane 4, the static pressure is constant in the annular region extending in the circumferential direction of the outlet flow path F. For this reason, leakage flow through the acoustic space 52 hardly occurs in this region. Therefore, by communicating the acoustic spaces 52 with each other, a large volume as the acoustic space 52 can be secured. As a result, the acoustic characteristics of the acoustic liner 5 can be further improved.

[0030] <Supplementary Note> The compressor 100 described in each embodiment is understood as follows, for example.

[0031] (1) The compressor 100 according to the first aspect includes a rotating shaft that rotates around an axis, an impeller that rotates together with the rotating shaft to pump fluid from one side in the axial direction toward the radially outer side, a casing that surrounds the rotating shaft and the impeller and forms an outlet flow path for guiding the fluid pumped from the impeller, and an acoustic liner provided so as to face the inside of the outlet flow path in the casing. The acoustic liner has a plurality of apertures arranged at intervals from each other, and an acoustic space that communicates with the apertures and is provided independently for each aperture.

[0032] According to the above configuration, since the acoustic space is provided independently for each aperture, the possibility of leakage flow from the high-pressure region on the downstream side of the outlet flow path toward the low-pressure region on the upstream side through the acoustic space can be reduced. As a result, the acoustic characteristics of the acoustic liner can be improved.

[0033] (2) In the compressor 100 according to the second aspect, in a region where the static pressures in the outlet flow path are equal to each other, the acoustic spaces communicate with each other.

[0034] According to the above configuration, in a region where the static pressures in the outlet flow path are equal to each other, a leakage flow through the acoustic space is less likely to occur. Therefore, by communicating the acoustic spaces with each other, a large volume as the acoustic space can be secured. Thereby, the acoustic characteristics of the acoustic liner can be further improved.

[0035] (3) The compressor 100 according to the third aspect is provided in the outlet flow path, and extends from the radially inner side to the outside with respect to the axis toward the front side in the rotational direction of the impeller, and further includes a plurality of diffuser vanes arranged at intervals in the circumferential direction. In a region extending in a direction orthogonal to the diffuser vanes, the acoustic spaces communicate with each other.

[0036] According to the above configuration, in a region extending in a direction orthogonal to the diffuser vanes, the static pressure is constant, and a leakage flow through the acoustic space is less likely to occur. Therefore, by communicating the acoustic spaces with each other, a large volume as the acoustic space can be secured. Thereby, the acoustic characteristics of the acoustic liner can be further improved.

[0037] (4) In the compressor 100 according to the fourth aspect, in an annular region centered on the axis in the outlet flow path and arranged in the radial direction, the acoustic spaces communicate with each other.

[0038] According to the above configuration, in a compressor without diffuser vanes, the static pressure is constant in an annular region extending in the circumferential direction of the outlet flow path. Therefore, in this region, a leakage flow through the acoustic space is less likely to occur. Therefore, by communicating the acoustic spaces with each other, a large volume as the acoustic space can be secured. Thereby, the acoustic characteristics of the acoustic liner can be further improved.

[0039] (5) In the compressor 100 according to the fifth aspect, the acoustic liner includes a first plate member in which a first hole portion serving as the opening portion is formed, and a second plate member laminated on the first plate member and having a second hole portion serving as the acoustic space formed at a position corresponding to the opening portion.

[0040] According to the above configuration, by simply laminating a first plate member in which a first hole portion is formed in advance and a second plate member in which a second hole portion is formed, an acoustic liner can be easily configured with high processing accuracy. Thereby, processing costs and maintenance costs can be reduced.

Explanation of Reference Numerals

[0041] 100 Compressor 1 Rotating shaft 2 Impeller 3 Casing 4 Diffuser vane 5 Acoustic liner 10 First plate member 11 Second plate member 12 Third plate member 21 Disk 21A Main surface 22 Blade 51 Opening portion 52 Acoustic space 61 First hole portion 62 Second hole portion O Axis F Outlet flow path F1 Diffuser flow path F2 Outlet scroll

Claims

1. A rotating shaft that rotates about an axis, An impeller that rotates with the rotating shaft and pumps fluid from one side in the axial direction toward the radially outer side, A casing that surrounds the rotating shaft and the impeller and forms an outlet flow path for guiding the fluid pumped from the impeller, An acoustic liner provided so as to face the inside of the outlet flow path in the casing, comprising The acoustic liner A plurality of apertures arranged at intervals from each other, An acoustic space that communicates with the apertures and is provided independently for each aperture, having Further comprising a plurality of diffuser vanes provided in the outlet flow path, extending from the radially inner side to the outer side with respect to the axis toward the front side in the rotation direction of the impeller, and arranged at intervals in the circumferential direction, When viewed from the axial direction, on the front side in the rotation direction of each diffuser vane, it is formed by a plurality of the apertures arranged in a row in a direction orthogonal to the extending direction of the diffuser vane, and a plurality of aperture groups are formed at intervals in the extending direction of the diffuser vane, The acoustic spaces communicating with the apertures belonging to the same aperture group communicate with each other, and the acoustic spaces communicating with the apertures belonging to different aperture groups do not communicate with each other. A compressor.

2. A rotating shaft that rotates about an axis, An impeller that rotates with the rotating shaft and pumps fluid from one side in the axial direction toward the radially outer side, A casing that surrounds the rotating shaft and the impeller and forms an outlet flow path for guiding the fluid pumped from the impeller, An acoustic liner provided so as to face the inside of the outlet flow path in the casing, comprising The acoustic liner A plurality of apertures arranged at intervals from each other, an acoustic space communicating with the apertures and provided independently for each of the apertures, and having, formed by a plurality of the apertures arranged in a row in an annular shape centered on the axis as viewed from the axial direction, and a plurality of aperture groups provided at intervals in the radial direction of the axis are formed, a compressor in which the acoustic spaces communicating with the apertures belonging to the same aperture group communicate with each other, and the acoustic spaces communicating with the apertures belonging to different aperture groups do not communicate with each other.

Images