KR20170091953A - Fluid machine - Google Patents

Abstract

A fluid machine comprises: a hub disposed to be rotated; a plurality of blades spaced in the circumferential direction with respect to a rotational center of the hub and disposed outside the hub; a flow passage extended in the circumferential direction with respect to the rotational center of the hub and disposed to cover the blades to be recessed from an inner surface formed toward the blades; and a shroud having a plurality of resonators disposed in the flow passage.

Description

Fluid machine

Embodiments relate to a fluid machine, and more particularly to a fluid machine in which aerodynamic performance is improved and noise generation is reduced.

Compressors or expanders or pumps that compress fluids have the structure of fluid machinery using rotating elements. Such a fluid machine has an impeller as a rotating element, and the impeller functions to increase the pressure of the fluid by transmitting rotational kinetic energy to the fluid. The impeller includes a plurality of blades that assist in fluid movement and transfer energy to the fluid.

On the other hand, a shroud is disposed outside the impeller, which forms a passage through which the fluid moves with the blades. In order to design a fluid machine with excellent performance, the aerodynamics performance in the passageway through which the fluid formed by the impeller and shroud must be maximized.

However, due to the formation of high pressure by the fluid during operation of the impeller, a large noise is generated between the impeller and the shroud. Although many attempts have been made to reduce the operating noise of such an impeller, aerodynamic loss occurs in the fluid machine when a separate device is installed in the impeller or shroud to reduce the noise.

Therefore, in the design of fluid machinery, there is a need to develop a technique that maintains excellent aerodynamic performance between the impeller and the shroud forming the passage through which the fluid passes, while reducing noise.

U.S. Patent No. 5,255,601 discloses a groove in a casing wall to reduce vibration, but this groove installation technique causes a loss of aerodynamic force.

Japanese Laid-Open Patent Application No. 2007-218147 discloses a technique in which a hole is provided in a shroud to reduce noise, but a simple structure in which a hole is formed in the wall of the shroud results in a loss of aerodynamic force.

Japanese Unexamined Patent Application Publication No. 2002-537184, Korean Unexamined Patent Publication No. 1998-0060499, and U.S. Patent No. 4540335 disclose techniques using holes to improve noise or improve flow characteristics. However, these techniques use a structure in which a hole is provided at the position of the casing corresponding to the tip (end portion) of the rotating blade, so that the hole mounting structure is formed by using the shroud covering the upper surface of the rotating blade, It is difficult to apply for improvement and noise reduction.

United States Patent No. 5256031 (October 26, 1993) Japanese Patent Laid-Open No. 2007-218147 (Aug. 30, 2007) Japanese Patent Application Laid-Open No. 2002-537184 (Nov. Korean Patent Publication No. 1998-0060499 (Oct. 7, 1998) United States Patent No. 4540335 (September 10, 1985)

The purpose of the embodiments is to provide a fluid machine with reduced noise generation by installing resonators in the shroud.

Another object of the embodiments is to provide a fluid machine with improved aerodynamic performance with resonators for noise generation.

A fluid machine according to one embodiment comprises a hub arranged to rotate, a plurality of blades spaced circumferentially about the hub of rotation of the hub and disposed outside the hub, and a plurality of blades spaced circumferentially about the center of rotation of the hub And a shroud having a plurality of resonators arranged in the flow path, the shroud being arranged to cover the blades, the shroud having a recess formed in the inner surface facing the blades, and a plurality of resonators arranged in the flow path.

Each of the resonators may have an opening that is open at the surface facing the blades of the flow path and a space portion that is connected to the opening and extends outwardly from the opening to form a hollow space within the shroud.

The fluid machine may further include a base disposed on the outside of the hub and extending along the center of rotation of the hub and supporting the blades.

The shroud may have an inlet for guiding the fluid towards the blades and an outlet for guiding the fluid through the blades to be discharged.

The flow path may extend from the inlet toward the outlet and be formed in at least a portion of the inner surface of the shroud.

Resonators can be arranged at the same density in the entire area of the flow path from the inlet to the outlet of the shroud.

The density at which the resonators are placed in the flow path can be increased toward the outlet from the inlet of the shroud.

Resonators can be placed in only some of the entire area of the flow path from the inlet to the outlet of the shroud.

Resonators can be arranged at a predetermined distance from the inlet of the shroud to the outlet.

The shroud may have a first plate disposed at a location in contact with the blade and having an opening in the flow path and resonators and a second plate disposed above the first plate with a space of resonators at a location corresponding to the opening .

According to the fluid machine of the above-described embodiments, the aerodynamic loss of the fluid passing between the shroud and the blades can be minimized due to the structure of the flow path formed in the shroud.

Also, since resonators are disposed on the surface of the flow path that guides the fluid flow so that fluid flows smoothly between the blades and the shroud, the noise generated by the compressed air between the blades and the shroud can be reduced .

FIG. 1 is a perspective view illustrating a coupling relationship of components of a fluid machine according to an embodiment. FIG.
2 is a perspective view showing a state in which the fluid machine of FIG. 1 is engaged.
3 is a cross-sectional view taken along line III-III of the fluid machine of FIG. 2;
Fig. 4 is an enlarged cross-sectional view of an enlarged view of part IV of the fluid machine of Fig. 3;
5 is a cross-sectional view taken along line III-III of the fluid machine of FIG. 2;
Figure 6 is a top view of the fluid machine of Figure 2;
FIG. 7 is an enlarged view of a portion of the shroud of the fluid machine of FIG. 1; FIG.
8 is an enlarged view showing a part of a shroud of a fluid machine according to another embodiment.
9 is an enlarged view showing a part of a shroud of a fluid machine according to yet another embodiment.
10 is a cross-sectional view showing an example of a process of manufacturing the shroud of the fluid machine shown in Figs. 1 to 9. Fig.
11 is a cross-sectional view showing another example of a process of manufacturing the shroud of the fluid machine shown in Figs. 1 to 9. Fig.
12 is a cross-sectional view of the shroud made by the process of Fig.
13 is an enlarged view showing a part of a shroud of a fluid machine according to yet another embodiment.

Hereinafter, the structure and operation of the fluid machine according to the embodiments will be described in detail through the embodiments of the accompanying drawings. The expression " and / or " used in the description refers to one of the elements or a combination of elements.

2 is a perspective view showing a state in which the fluid machine of FIG. 1 is engaged, and FIG. 3 is a perspective view of the fluid machine of FIG. 2, Sectional view taken along line III-III of Fig.

The fluid machine according to the embodiment shown in Figs. 1 to 3 has a hub 10, a plurality of blades 21 disposed on the outside of the hub, a shroud 30 arranged to cover the blades 21, Respectively.

In the embodiments shown in the drawings, the rotary machine is implemented as a compressor, but the embodiments are not limited thereto. That is, it is sufficient that the rotating machine according to the embodiment is a device capable of changing the pressure and speed of the fluid by the rotational motion of the impeller. For example, the rotating machine according to the embodiment may be implemented with an expander (turbine), a pump, a blower, or the like for expanding the fluid.

The hub 10 is rotatably disposed with a shaft coupling hole 10a into which a rotation shaft is inserted. On the outside of the hub (10), a base (22) extending in the circumferential direction is arranged with its outer diameter increasing in the radial direction along the vertical direction.

The base 22 is coupled to the outside of the hub 10 and is formed so as to radially increase the outer diameter along the up-and-down direction. Since the surface of the base 22 is formed to be a sloped curved surface, the bottom surface of the passage through which the fluid passes is designed to smooth the flow of the fluid and transmit the maximum energy to the fluid.

A plurality of blades (21) are arranged outside the hub (10) at predetermined intervals along the circumferential direction with respect to the center of rotation of the hub (10). The blades 21 can be disposed outside the hub 10 by placing the blades 21 on the base 22 and the base 22 on the outside of the hub 10. The blades 21 extend radially outward from the hub 10.

The impeller 20 including the hub 10, the blades 21 and the base 22 functions to transfer the kinetic energy of the impeller 20 to the fluid while guiding the movement of the fluid.

The shroud 30 has an inlet 38 with a top open fluid and has an outlet 39 of fluid extending radially downwardly from the inlet 38 at the open top. The shroud 30 forms the ceiling surface of the passage through which the fluid passes and forms a passage through which the fluid moves with the base 22 and the blades 21.

3, when the fluid machine is designed as an inflator (turbine), the inlet 38 of the fluid is designed to perform the function of an outlet, and the outlet 39 of the fluid functions as an inlet .

The inlet (38) of the shroud (30) directs the fluid towards the blades (21). The outlet (39) of the shroud (30) also directs the fluid to be discharged by the blades (21) to the outside of the shroud (30).

The shroud 30 extends in the circumferential direction with respect to the center of rotation of the hub 10 and is arranged to cover the upper end of the blades 21. [ The shroud 30 and the blades 21 may be secured to one another, for example, by a welding process or by fastening means such as rivets or bolts. When the shroud 30 and the blades 21 are fixed to each other, the hub 10, the blades 21, and the shroud 30 can rotate together.

The shroud 30 is not fixed to the blades 21 and the shroud 30 is positioned outside the blades 21 so that the shroud 30 maintains a relatively fixed position relative to the hub 10 and the blades 21. [ Can be fixed to the structure. The shroud 30 maintains a fixed position relative to the hub 10 and the blades 21 while the hub 10 and the blades 21 rotate when the shroud 30 is secured to an external structure Thereby providing a portion of the passage through which the fluid passes.

When the impeller 20 rotates, the fluid introduced from the inlet 38 of the shroud is discharged to the outside through the outlet 39 of the shroud by the centrifugal force. The centrifugal force of the impeller 20 causes the fluid to be compressed to a high pressure state and to exit through the outlet 39. The fluid discharged to the outside of the impeller 20 through the outlet 39 is reduced in speed while passing through, for example, a diffuser (not shown), and at the same time, the pressure rises to a required level.

The shroud 30 has a flow path 32 formed concavely in the inner surface 30a facing the blades 21. [ The flow path 32 extends radially from the inlet 38 of the shroud 30 toward the outlet 39. The shroud 30 also includes a plurality of resonators 40 (resonators) disposed in the flow path 32.

The flow path 32 formed in the shroud 30 is compressed by the rotational motion of the blades 21 and functions to guide the flow of the fluid so that the flowing fluid can smoothly move. The flow path 32 extends radially outwardly from the hub 10 along the direction in which the blades 21 are formed and curves in the circumferential direction. The air flow loss of the fluid passing between the shroud 30 and the blades 21 can be minimized due to the structure of the flow path 32 formed in the shroud 30.

Fig. 4 is an enlarged cross-sectional view of a portion of the fluid machine of Fig. 3, Fig. 5 is a cross-sectional view taken along line III-III of the fluid machine of Fig. 2, to be.

Each of the resonators 40 includes an opening 41 that is open at the surface of the flow path 32 toward the blades 21 and an opening 41 that is connected to the opening 41 and extends outwardly from the opening 41, And a space portion 42 for forming a hollow space (an empty space inside).

Each of the opening 41 and the space portion 42 may have a circular cross section or a polygonal cross section. Further, the size of the cross-sectional area of the space portion 42 is formed larger than the size of the cross-sectional area of the opening 41.

The resonators 40 are formed on the surface of the flow path 32 for guiding the flow of the fluid so as to smoothly flow the fluid between the blades 21 and the shroud 30, 30 can be reduced by the air compressed by the high pressure.

The cross sectional area and the size and the arrangement position of the space portion 42 of the opening 41 of the resonators 40 are designed in consideration of the frequency of the noise generated between the shroud 30 and the blades 21. [ That is, from the surface of the flow path 32 of the opening 41 to the space portion 42 in consideration of the resonance frequency that may occur between the shroud 30 and the blades 21, And the volume of the space portion 42 can be experimentally designed.

FIG. 7 is an enlarged view of a portion of the shroud of the fluid machine of FIG. 1; FIG.

A flow path 32 formed in the shroud 30 extends from the inlet 38 toward the outlet 39 and is formed on the inner surface of the shroud 30. 7, the flow path 32 is formed in the entire section of the inner surface of the shroud 30 from the inlet 38 to the outlet 39 of the shroud 30, The flow path 32 is not limited to the length of the shroud 32 and the flow path 32 may be formed only in a part of the inner surface of the shroud 30 extending from the inlet 38 to the outlet 39 of the shroud 30.

7, the resonators 40 are arranged at the same density in the entire region of the flow path 32 from the inlet 38 to the outlet 39 of the shroud 30. The distance d between the resonators 40 disposed adjacent the inlet 38 and the distance d between the resonators 40 disposed adjacent the outlet 39 as shown in Figure 7 ) Are the same. Therefore, the same level of noise reduction effect can be obtained for the entire area of the flow path 32 from the inlet 38 to the outlet 39 of the shroud 30.

8 is an enlarged view showing a part of a shroud of a fluid machine according to another embodiment.

The shroud 130 of the fluid machine according to the embodiment shown in FIG. 8 is generally similar to that of the shroud 30 shown in FIG. 7, but the density at which the resonators 140 are disposed has been modified.

Referring to FIG. 8, the density at which the resonators 140 are disposed in the entire region of the flow path 132 from the inlet 138 to the outlet 139 of the shroud 130 changes. The density at which the resonators 140 are disposed in the flow path 132 is increased toward the outlet 139 from the inlet 138 of the shroud 130.

The distance d2 between the resonators 140 disposed adjacent the outlet 139 relative to the distance d1 between the resonators 140 disposed adjacent the inlet 138 as shown in Fig. . Therefore, the noise reduction effect of the resonators 140 is increased at the outlet 139 side rather than at the inlet 138 side of the shroud 130. The structure in which the densities of the resonators 140 disposed adjacent to the outlet 139 side are increased can be applied to the case where the noise is greatly increased on the side of the outlet 139 as compared with the inlet 138.

9 is an enlarged view showing a part of a shroud of a fluid machine according to yet another embodiment.

The shroud 230 of the fluid machine according to the embodiment shown in Fig. 9 is entirely similar to that of the shroud 30 shown in Fig. 7, but the position in which the resonators 240 are disposed has been modified.

9, resonators 240 are disposed in only a part of the entire area of the flow path 232 from the inlet 238 to the outlet 239 of the shroud 230. The resonators 240 are spaced from the area corresponding to the position spaced apart by a predetermined distance d0 from the inlet 238 of the shroud 230 toward the outlet 239 in the entire area of the flow path 232, .

The density at which the resonators 240 are disposed in the flow path 232 can be set to be the same overall. The distance d3 between the resonators 240 close to the inlet 238 side and the distance d4 between the resonators 240 nearer to the outlet 239 side are smaller than the distance d2 between the near resonator 240 and the resonator 240. [ They remain the same.

The embodiments are not limited to the configuration in which the densities of the resonators 240 disposed in the flow path 232 are uniformly arranged as shown in FIG. The arrangement densities of the resonators 240 shown in Fig. 9 are modified so that the distance d3 between the resonators 240 close to the inlet 238 side and the distance d3 between the resonators 240 close to the outlet 239 side And the distance d4 are different from each other.

According to the structure of the shroud 230 and the resonators 240 having the above-described configuration, until the predetermined distance d0 from the inlet 238 of the shroud 230 toward the outlet 239 is reached, A smooth fluid flow can be formed by the region of the flow path 232 where the resonators 240 are not disposed. The resonators 240 are arranged in the region from the inlet 238 of the shroud 230 to the outlet 239 by a predetermined distance d0 corresponding to the region where the noise is greatly increased in the entire region of the flow path 232 The noise reduction effect can be maximized.

In the embodiments described above, the size of the resonators formed in the shroud, that is, the diameter, length and volume of the opening and the volume of the space are shown to be constant. However, the size of the resonators may vary depending on the location of the resonators in the shroud's flow path. The size of the openings and spaces of the resonators arranged adjacent to the inlet side of the shroud can be designed small and the size of the openings and spaces of the resonators arranged adjacent to the outlet side of the shroud can be designed to be large . Also, the size of the resonators may gradually be increased or decreased from the entrance to the exit of the shroud.

10 is a cross-sectional view showing an example of a process of manufacturing the shroud of the fluid machine shown in Figs. 1 to 9. Fig.

10 shows an example of a process of manufacturing a shroud 330 of a fluid machine using a mold. When the upper mold 7 and the lower mold 8 are joined to each other and the fluid is injected and solidified, the shroud 330 having the concaved flow path 332 on one side is completed. The lower mold 8 has a shape corresponding to the resonators 340 of the flow path 332 of the shroud 330 so that the flow path 332 of the shroud 330 is opened at the surface of the flow path 332 Resonators 340 are formed that extend outwardly from the openings 341 and 341 and have a space 342 that defines a hollow space within the shroud 330.

After the upper mold 7 and the lower mold 8 are removed and the surface of the shroud 330 is cleaned after the shroud 330 is solidified, the manufacture of the shroud 330 is completed.

Fig. 11 is a cross-sectional view showing another example of a process of manufacturing the shroud of the fluid machine shown in Figs. 1 to 9, and Fig. 12 is a sectional view of the shroud made by the process of Fig.

11 and 12 show another example of a process for manufacturing a shroud 430 of a fluid machine by a method of attaching two metal plates.

11, the process of preparing the shroud includes the steps of preparing the first plate 430a, preparing the second plate 430b, preparing the first plate 430a and the second plate 430b, .

The first plate 430a is a component that forms an inner surface in contact with the blades of the shroud. The step of preparing the first plate 430a may be performed by preparing a metal plate, and at least a plurality of processing methods such as punching, hammering, pressing, bending, And forming the channel 432 and the opening 441 by applying one.

The second plate 430b is a component that forms an outer surface opposite the inner surface in contact with the blades of the shroud. The step of preparing the second plate 430b may be performed by preparing a metal plate, and at least a plurality of processing methods such as punching, hammering, pressing, bending, And forming the space portion 442 by applying one.

When the first plate 430a and the second plate 430b are prepared, the opening 441 of the first plate 430a and the space 442 of the second plate 430b are aligned with the first plate 430a Aligning the position of the second plate 430b with the position of the second plate 430b, and bonding the first plate 430a and the second plate 430b.

The step of joining the first plate 430a and the second plate 430b may be performed by, for example, applying an adhesive between the first plate 430a and the second plate 430b, It is possible to use various methods such as using a fastening means such as rivets or bolts passing through the second plate 430b or by welding the inner edge or the inner edge of the first plate 430a and the second plate 430b . ≪ / RTI >

The completed shroud 430 has a first plate 430a disposed at a position in contact with the blade and having a flow path 432 and an opening 441 and a second plate 430b disposed at a position corresponding to the opening 441, And a second plate (430b) having a portion (442). When the first plate 430a and the second plate 430b are joined to each other, the opening 441 of the first plate 430a and the space 442 of the second plate 430b are connected to each other, 440 are formed.

13 is an enlarged view showing a part of a shroud of a fluid machine according to yet another embodiment.

The shroud 530 according to the embodiment shown in Fig. 13 has a first plate 530a having a flow path 532 formed on its inner side and a plurality of honeycomb-shaped holes 530a, And a second plate (530b) having a plurality of grooves (535).

When the second plate 530b is coupled to each of the flow paths 532 of the first plate 530a to complete the shroud 530, a honeycomb shape is formed on the surface of the flow path 532 of the shroud 530 facing the blades Holes 535 are disposed.

According to the shroud 530 having such a structure, since the flow path 532 for smoothly guiding the flow of the fluid is provided with the honeycomb-shaped holes 535 for reducing the noise, it is possible to minimize the loss of aerodynamic force, Effect can be obtained.

The construction and effect of the above-described embodiments are merely illustrative, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Accordingly, the true scope of protection of the invention should be determined by the appended claims.

7: Upper mold 39, 139, 239: Outlet
8: Lower mold 40, 140, 240, 340, 440: Resonators
10: hub 41, 341, 441: opening
10a: axis coupling holes 42, 342, 442:
20: impeller 130, 230, 330, 430, 530: shroud
21: blades 32, 132, 232, 332, 432, 532:
22: Base 430a, 530a: First plate
30: shroud 430b, 530b: second plate
30a: Inner side 535: Holes
38, 138, 238: entrance

Claims (10)

A hub disposed to rotate;
A plurality of blades spaced circumferentially about a center of rotation of the hub and disposed outside the hub; And
A shroud extending along the circumferential direction with respect to the center of rotation of the hub, the shroud being disposed to cover the blades, the shroud having a plurality of resonators disposed in the flow path; Han, fluid machine. The method according to claim 1,
Wherein each of the resonators has an opening that is open at a surface facing the blades of the flow path and a space portion that is connected to the opening and extends outwardly from the opening to form a hollow space within the shroud. . The method according to claim 1,
Further comprising a base disposed on the outer side of the hub and extending along the center of rotation of the hub and supporting the blades. The method according to claim 1,
Wherein the shroud has an inlet for guiding fluid into the blades and an outlet for guiding the fluid through the blades to discharge. 5. The method of claim 4,
Said flow path extending from said inlet toward said outlet and being formed at least in a section of said inner surface of said shroud. 5. The method of claim 4,
Wherein the resonators are arranged at the same density in the entire region of the flow path from the inlet to the outlet of the shroud. 5. The method of claim 4,
Wherein the density at which the resonators are disposed in the flow path increases from the inlet to the outlet of the shroud. 5. The method of claim 4,
Wherein the resonators are disposed only in a portion of the entire area of the flow path from the inlet to the outlet of the shroud. 9. The method of claim 8,
Wherein the resonators are located at a predetermined distance from the inlet of the flow path of the shroud toward the outlet. 3. The method of claim 2,
Wherein the shroud is disposed at a location in contact with the blade and has a first plate having the openings of the flow path and the resonators and a second plate having the space of the resonators at a location corresponding to the opening, And a second plate on which the second plate is mounted.

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