KR102488570B1 - Fluid machine - Google Patents

Abstract

A fluid machine includes a hub disposed to rotate, a plurality of blades spaced apart from each other in a circumferential direction with respect to the rotational center of the hub and disposed outside the hub, extending along the circumferential direction with respect to the rotational center of the hub and covering the blades. A shroud having a passage formed concavely on an inner surface facing the blades and a plurality of resonators disposed in the passage is provided.

Description

Fluid machine {Fluid machine}

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

A compressor, expander, or pump that compresses fluid has a structure of a fluid machine using a rotating element. Such a fluid machine has an impeller as a rotating element, and the impeller serves to increase the pressure of the fluid by transferring rotational kinetic energy to the fluid. The impeller has a plurality of blades that help move the fluid and transfer energy to the fluid.

On the other hand, a shroud is disposed outside the impeller, and the shroud forms a passage through which the fluid moves along with the blades. In order to design a fluid machine with excellent performance, it is necessary to maximize aerodynamics performance in a passage through which a fluid formed by an impeller and a shroud moves.

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

Therefore, in the design of a fluid machine, it is required to develop a technology capable of reducing noise while maintaining excellent aerodynamic performance between an impeller and a shroud forming a passage through which fluid passes.

US Patent Registration No. 5256031 installs a groove on the casing wall to reduce vibration, but according to this groove installation technique, aerodynamic loss becomes severe.

Japanese Patent Laid-open Publication No. 2007-218147 shows a technique of installing a hole in the shroud to reduce noise, but the aerodynamic loss becomes severe according to the simple structure in which the hole is installed in the wall of the shroud.

Japanese Patent Publication No. 2002-537184, Korean Patent Publication No. 1998-0060499, and US Patent Registration No. 4540335 show a technique using a hole to improve noise or flow characteristics. However, since these technologies use a structure in which a hole is installed at the position of the casing corresponding to the tip (end) of the rotating blade, the aerodynamic performance of the fluid machine using this hole installation structure with a shroud covering the upper surface of the rotating blade Difficult to apply for enhancement and noise reduction.

US Patent No. 5256031 (1993.10.26.) Japanese Unexamined Patent Publication No. 2007-218147 (2007.08.30.) Japanese Unexamined Patent Publication No. 2002-537184 (2002.11.05.) Korean Patent Publication No. 1998-0060499 (1998.10.07.) US Patent No. 4540335 (1985.09.10.)

An object of the embodiments is to provide a fluid machine in which noise generation is reduced by installing resonators in a shroud.

Another object of the embodiments is to provide a fluid machine having improved aerodynamic performance while having resonators for generating noise.

A fluid machine according to an embodiment includes a hub disposed to rotate, a plurality of blades spaced apart from each other in a circumferential direction with respect to a rotational center of the hub and disposed outside the hub, and extending along a circumferential direction with respect to the rotational center of the hub. and a shroud having a flow path disposed to cover the blades and concavely formed on an inner surface facing the blades, and a plurality of resonators disposed in the flow path.

Each of the resonators may have an opening opened on a surface facing the blades of the passage, and a space portion connected to the opening and extending outward from the opening to form a hollow space inside the shroud.

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

The shroud may have an inlet for guiding fluid to be introduced toward the blades and an outlet for guiding fluid to be discharged after passing through the blades.

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

The same density of resonators can be arranged in the entire area of the passage from the inlet to the outlet of the shroud.

The density of resonators disposed in the flow path may increase from the inlet to the outlet of the shroud.

Resonators may be disposed only in a partial area of the entire area of the flow path extending from the inlet to the outlet of the shroud.

Resonators may be disposed from positions spaced apart by a predetermined distance from the inlet of the shroud flow path toward the outlet.

The shroud may include a first plate disposed at a position in contact with the blade and having openings of the resonators and a flow path, and a second plate disposed on the first plate and having space portions of the resonators at positions corresponding to the openings. .

According to the fluid machine according to 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 passage formed in the shroud.

In addition, since resonators are placed on the surface of the passage that guides the flow of fluid so that the fluid flows smoothly between the blades and the shroud, noise that may be generated by high-pressure compressed air between the blades and the shroud can be reduced. can

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

Hereinafter, the configuration 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 during the description means one of related elements or a combination of elements.

1 is a perspective view showing the coupled relationship of components of a fluid machine according to an embodiment in isolation, FIG. 2 is a perspective view showing a coupled state of the fluid machine of FIG. 1, and FIG. 3 is a fluid machine of FIG. 2 It is a cross-sectional view taken along the line of Ⅲ-Ⅲ.

The fluid machine according to the embodiment shown in FIGS. 1 to 3 includes a hub 10, a plurality of blades 21 disposed outside the hub, and a shroud 30 disposed to cover the blades 21. to provide

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

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

The base 22 is coupled to the outside of the hub 10 and is formed so that its outer diameter increases radially along the vertical direction. Since the surface of the base 22 is formed to form an inclined curved surface, it is designed to transfer maximum energy to the fluid while smoothing the flow of the fluid by forming the bottom surface of the passage through which the fluid passes.

On the outside of the hub 10, a plurality of blades 21 are spaced apart from each other at predetermined intervals along the circumferential direction with respect to the center of rotation of the hub 10. Since the blades 21 are disposed on the base 22 and the base 22 is coupled to the outside of the hub 10 , the blades 21 may be disposed on the outside of the hub 10 . The blades 21 extend radially outward from the hub 10 .

The impeller 20 including the hub 10, blades 21, and base 22 performs a function of guiding the movement of the fluid and transmits kinetic energy of the impeller 20 to the fluid.

The shroud 30 has a fluid inlet 38 with an open upper end, and has a fluid outlet 39 extending radially downward from the inlet 38 of the open upper end. The shroud 30 forms a ceiling surface of a passage through which fluid passes, and together with the base 22 and the blades 21 form a passage through which fluid moves.

Referring to FIG. 3, as a modified example, when a fluid machine is designed as an expander (turbine), the fluid inlet 38 is designed to function as an outlet, and the fluid outlet 39 serves as an inlet. can be made to do.

The inlet 38 of the shroud 30 guides the fluid so that it can flow toward the blades 21 . Also, the outlet 39 of the shroud 30 guides the fluid moved by the blades 21 to be discharged to the outside of the shroud 30 .

The shroud 30 extends in a circumferential direction with respect to the center of rotation of the hub 10 and is disposed to cover upper ends of the blades 21 . The shroud 30 and the blades 21 may be fixed to each other, for example, by a welding process or by using 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 may rotate together.

The shroud 30 is not fixed to the blades 21, and the shroud 30 maintains a relatively fixed position with respect to the hub 10 and the blades 21. Can be fixed to the structure. When the shroud 30 is fixed to an external 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. By doing so, it provides a part 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 centrifugal force. That is, the fluid is compressed into a high-pressure state by the centrifugal force according to the rotational kinetic energy of the impeller 20 and exits through the outlet 39 . The fluid discharged to the outside of the impeller 20 through the outlet 39 slows down 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 passage 32 concavely formed on the inner surface 30a facing the blades 21 . A 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 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 serves to guide the flow of fluid so that the moving fluid can move smoothly. The passage 32 extends radially outward from the hub 10 along the direction in which the blades 21 are formed and is curved in the circumferential direction at the same time. Due to the structure of the passage 32 formed in the shroud 30 as described above, aerodynamic loss of fluid passing between the shroud 30 and the blades 21 can be minimized.

4 is an enlarged cross-sectional view of the fluid machine of FIG. 3 enlarged at section IV, FIG. 5 is a cross-sectional view taken along the line III-III of the fluid machine of FIG. 2, and FIG. 6 is a top view of the fluid machine of FIG. 2 to be.

Each of the resonators 40 is connected to an opening 41 opened on the surface of the flow path 32 facing the blades 21 and is connected to the opening 41 and extends outward from the opening 41 so that the shroud 30 ) is provided with a space portion 42 forming a hollow (empty inside) space inside.

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

The resonators 40 are formed on the surface of the flow path 32 that guides the flow of fluid so that the fluid flows smoothly between the blades 21 and the shroud 30, so that the blades 21 and the shroud ( 30), it is possible to reduce noise that may be generated by high-pressure compressed air.

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

7 is an enlarged view showing a part of the shroud of the fluid machine of FIG. 1 in an enlarged manner.

The 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 . In the embodiment shown in FIG. 7, the flow path 32 is formed on the entire section of the inner surface of the shroud 30 from the inlet 38 to the outlet 39 of the shroud 30, but the embodiment does not have such a flow path. The length of the shroud 32 is not limited, and the passage 32 may be formed only in a portion of the inner surface of the shroud 30 from the inlet 38 to the outlet 39 of the shroud 30 .

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

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

The structure of 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 is modified.

Referring to FIG. 8 , the density at which resonators 140 are disposed varies over the entire area of the passage 132 from the inlet 138 to the outlet 139 of the shroud 130 . The density of the resonators 140 disposed in the flow path 132 increases from the inlet 138 to the outlet 139 of the shroud 130 .

As shown in FIG. 8, the distance d2 between resonators 140 disposed adjacent to the outlet 139 is greater than the distance d1 between resonators 140 disposed adjacent to the inlet 138. decreases. Therefore, the noise reduction effect of the resonators 140 is increased at the outlet 139 side of the shroud 130 rather than at the inlet 138 side. The structure in which the density of the resonators 140 disposed adjacent to the outlet 139 is increased in this way can be applied when noise is greatly increased at the outlet 139 compared to the inlet 138.

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

The shroud 230 of the fluid machine according to the embodiment shown in FIG. 9 is generally similar to the structure of the shroud 30 shown in FIG. 7, but the position where the resonators 240 are disposed is modified.

Referring to FIG. 9 , resonators 240 are disposed only in a partial area of the entire area of the flow path 232 extending from the inlet 238 to the outlet 239 of the shroud 230 . The resonators 240 are resonators 240 from an area corresponding to a position spaced apart from the inlet 238 toward the outlet 239 of the shroud 230 by a predetermined distance d0 among the entire area of the flow path 232 . ) is placed.

A density of the resonators 240 disposed in the flow path 232 may be set to be the same throughout. When the arrangement density of the resonators 240 is the same, the distance d3 between the resonators 240 close to the inlet 238 and the distance d4 between the resonators 240 close to the outlet 239 are remain identical to each other.

As shown in FIG. 9 , the embodiments are not limited by a configuration in which the density of the resonators 240 disposed in the flow path 232 is uniform throughout. By modifying the arrangement density of the resonators 240 shown in FIG. 9, the distance d3 between the resonators 240 close to the inlet 238 and the resonators 240 close to the outlet 239 The distance d4 can be designed to be different from each other.

According to the structure of the shroud 230 and the resonators 240 of the above-described configuration, the resonators from the inlet 238 of the shroud 230 toward the outlet 239 until a predetermined distance d0 is reached. Since the resonators 240 are not disposed, smooth fluid flow may be formed by the region of the flow path 232 where the resonators 240 are not disposed. In addition, the resonators 240 are placed in an area of the entire area of the flow path 232 by a predetermined distance d0 from the inlet 238 of the shroud 230 toward the outlet 239 corresponding to the area where noise is greatly increased. By placing it, you can maximize the noise reduction effect.

In the above-described embodiments, 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 according to the positions where the resonators are disposed in the flow path of the shroud. For example, the size of the opening and the space of the resonators disposed adjacent to the inlet side of the shroud may be designed to be small, and the size of the opening and the space unit of the resonators disposed adjacent to the outlet side of the shroud may be designed to be large. . In addition, the size of the resonators may be modified to gradually increase or decrease from the inlet of the shroud toward the outlet.

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;

10 shows an example of a process of manufacturing the shroud 330 of a fluid machine using a mold. When fluid is injected and solidified in a state where the upper mold 7 and the lower mold 8 are coupled to each other, the shroud 330 having the concavely formed flow path 332 on one surface is completed. Since the lower mold 8 has a shape corresponding to the resonators 340 of the passage 332 of the shroud 330, the passage 332 of the shroud 330 has openings on the surface of the passage 332. Resonators 340 having an opening 341 and a space portion 342 forming a hollow space inside the shroud 330 by extending outward from the opening 341 are formed.

After the shroud 330 is solidified, the upper mold 7 and the lower mold 8 are removed and a cleaning process of cleaning the surface of the shroud 330 is performed to complete the manufacture of the shroud 330 .

11 is a cross-sectional view showing another example of a process for manufacturing the shroud of the fluid machine shown in FIGS. 1 to 9 , and FIG. 12 is a cross-sectional view of the shroud manufactured by the process of FIG. 11 .

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

Referring to FIG. 11 , the process of manufacturing the shroud includes preparing a first plate 430a, preparing a second plate 430b, first plate 430a and second plate 430b. It includes the step of bonding.

The first plate 430a is a component forming an inner surface in contact with the blades of the shroud. The step of preparing the first plate 430a is, for example, preparing a metal plate, and at least one of various processing methods such as punching, hammering, pressing, and bending of the metal plate. forming the flow path 432 and the opening 441 by applying one.

The second plate 430b is a component forming an outer surface opposite to an inner surface in contact with the blades of the shroud. The step of preparing the second plate 430b is, for example, preparing a metal plate, and at least one of various processing methods such as punching, hammering, pressing, and bending of the metal plate. forming the space 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 correspond to each other so that the first plate 430a ) and the second plate 430b, and bonding the first plate 430a and the second plate 430b are executed.

The step of bonding the first plate 430a and the second plate 430b is, for example, applying an adhesive between the first plate 430a and the second plate 430b, or applying an adhesive between the first plate 430a and the second plate 430a. 2 Using various methods such as using fastening means such as rivets or bolts penetrating the plate 430b or welding the inner edges or inner edges of the first plate 430a and the second plate 430b can be performed by

The shroud 430 completed through the above-described steps is disposed at a position in contact with the blade and has a first plate 430a having a passage 432 and an opening 441, and a space at a position corresponding to the opening 441. A second plate 430b having a portion 442 is provided. In a state in which the first plate 430a and the second plate 430b are bonded 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 so that the resonators ( 440) is formed.

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

The shroud 530 according to the embodiment shown in FIG. 13 is manufactured to have a first plate 530a having a flow path 532 formed on the inner surface and an outer shape corresponding to the flow path 532, and has a plurality of honeycomb holes. and a second plate 530b having sills 535 .

When the shroud 530 is completed by coupling the second plate 530b to each passage 532 of the first plate 530a, a honeycomb shape is formed on the surface of the passage 532 of the shroud 530 facing the blades. The holes 535 of are arranged.

According to the shroud 530 having such a structure, since honeycomb-shaped holes 535 capable of reducing noise are provided in the passage 532 that smoothly guides the flow of fluid, aerodynamic loss is minimized and noise is reduced. effect can be obtained.

The description of configurations and effects of the above-described embodiments is merely illustrative, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the invention will be determined by the appended claims.

7: upper mold 39, 139, 239: exit
8: lower mold 40, 140, 240, 340, 440: resonators
10: hub 41, 341, 441: opening
10a: shaft coupling hole 42, 342, 442: space
20: impeller 130, 230, 330, 430, 530: shroud
21: blades 32, 132, 232, 332, 432, 532: Euro
22: base 430a, 530a: first plate
30: shroud 430b, 530b: second plate
30a: inner surface 535: holes
38, 138, 238: entrance

Claims (10)

a hub arranged to rotate;
a plurality of blades spaced apart along a circumferential direction with respect to the center of rotation of the hub and disposed outside the hub; and
A shroud having a flow path extending in a circumferential direction with respect to the rotation center of the hub and covering the blades and formed concavely on an inner surface facing the blades, and a plurality of resonators disposed in the flow path. do,
The shroud has an inlet for guiding the fluid to flow toward the blades and an outlet for guiding the fluid passing through the blades to be discharged,
The fluid machine according to claim 1 , wherein a density of the resonators disposed in the flow path increases from the inlet of the shroud toward the outlet. According to claim 1,
Each of the resonators has an opening opened on a surface of the flow path facing the blades, and a space portion connected to the opening and extending outward from the opening to form a hollow space inside the shroud. . According to claim 1,
and a base disposed on the outer side of the hub, extending along the center of rotation of the hub, and supporting the blades. delete According to claim 1,
wherein the flow path extends from the inlet toward the outlet and is formed in at least a part of the inner surface of the shroud. delete delete According to claim 1,
The fluid machine, wherein the resonators are disposed only in a partial area of the entire area of the flow path extending from the inlet to the outlet of the shroud. According to claim 8,
wherein the resonators are disposed from positions spaced apart by a predetermined distance from the inlet of the flow path of the shroud toward the outlet. a hub arranged to rotate;
a plurality of blades spaced apart along a circumferential direction with respect to the center of rotation of the hub and disposed outside the hub; and
A shroud having a flow path extending in a circumferential direction with respect to the rotation center of the hub and covering the blades and formed concavely on an inner surface facing the blades, and a plurality of resonators disposed in the flow path. do,
Each of the resonators has an opening formed on a surface of the passage facing the blades, and a space portion connected to the opening and extending outward from the opening to form a hollow space inside the shroud,
The shroud includes a first plate disposed at a position in contact with the blade and provided with the passage and the openings of the resonators, and a space portion of the resonators at a position corresponding to the opening, and is disposed on the first plate. A fluid machine having a second plate to be.

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