KR20140106975A - compression device having pressure control device and pressure control method using the same - Google Patents

Abstract

Disclosed are a compression apparatus with a pressure control device and a pressure control method using the same. The disclosed compression apparatus comprises an impeller coupled to a rotary shaft, and having multiple blades; a shroud surrounding the impeller; a diffuser positioned at the periphery of the impeller, and having multiple vanes; a volute positioned at the periphery of the diffuser, and forming an area; and a pipe coupled to the outlet of the volute, wherein the pipe has a pressure control part generating loss in a slipstream. According to the present invention, a component decreasing pressure in the slipstream is installed from a point on which a flow becomes unstable by stall or the like in the impeller, the diffuser, etc., so pressure decreased by the instability of the flow at a front end can be similar to the pressure in the slipstream, thereby preventing the reversal of the flow by interrupting the increase of an adverse pressure gradient.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a compression device having a pressure control device and a pressure control method using the same,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a compression device, and more particularly, to a compression device having a pressure control device for delaying a surge phenomenon and a pressure control method using the compression device.

Typically, a compression device such as a centrifugal compressor is a compression device that allows a fluid to compress by applying a centrifugal force to the fluid using an impeller that performs rotational motion.

Not only the compression efficiency of the compression device but also the operation area such as turn down ratio are important performance variables, and therefore the required level varies depending on the place where the compression device is installed and the usage. In this case, the operation region refers to a region from the region where the compression device can operate, that is, the flow rate at which a surge is generated based on a required flow rate.

The reason why the surge occurs is that the flow becomes unstable at a specific section such as an impeller inlet or a diffuse vane shear stage, that is, stall is gradually developed, and at some point, This is due to the increase of the pressure at the upstream of the flow and the instantaneous back pressure gradient.

In order to delay surge occurrence, ie to operate the compression device over a wider flow range, the surge protection system should be applied to the design of the component itself, such as impellers, diffusers, volutes, Can be, but there is a limit.

In the "centrifugal compressor" disclosed in Korean Patent Publication No. 2011-0053625, it is possible to adjust not only the radial gap of the diffuser vane to the impeller but also the angle, so that the efficiency is maintained higher than that of the conventional compressor, And the like. However, the centrifugal compressor disclosed in Korean Patent Publication No. 2011-0053625 is not easy to prevent flow instability phenomenon.

Disclosure of Invention Technical Problem [8] The present invention provides a compression device having a pressure regulating device that smoothes the flow of a flow in a wide flow rate range by delaying surge phenomenon, and a pressure regulating method using the same.

According to an aspect of the present invention,

An impeller coupled to the rotating shaft and having a plurality of blades,

A shroud surrounding the impeller,

A diffuser located at an outer periphery of the impeller and including a plurality of vanes;

A volute disposed at an outer periphery of the diffuser and forming an area,

And a pipe connected to an outlet of the volute,

On the piping side, a pressure regulating portion for generating a loss in the downstream is provided.

In one embodiment, the pressure regulator includes an opening / closing unit for varying a passage area in the pipe, a driving unit connected to the opening / closing unit for rotating the opening / closing unit, and a control unit for transmitting a driving signal to the driving unit do.

In one embodiment, the opening / closing portion is a variable valve installed in the pipe and rotatably installed in a direction in which the inner diameter of the opening / closing portion is reduced so that the passage area in the pipe is narrowed.

In one embodiment, the opening / closing portion is a variable diaphragm installed in the pipe and rotatably installed in a direction in which the width of the opening / closing portion is widened so as to narrow the passage area in the pipe.

According to another aspect of the present invention,

At least one compression section disposed at least in one end; And

And a pressure adjusting unit installed at an outlet of the compression unit and generating a loss at a downstream.

In one embodiment, the pressure regulating unit includes: an opening / closing unit for varying a passage area in a pipe connected to the outlet of the compression unit; a driving unit connected to the opening / closing unit to rotate the opening / closing unit; And a controller.

In one embodiment, the opening / closing portion is a variable valve installed in the pipe and rotatably installed in a direction in which the inner diameter of the opening / closing portion is reduced so as to narrow the passage area in the pipe.

In one embodiment, the opening / closing portion is a variable diaphragm installed in the piping and rotatably installed in a direction in which the width of the opening / closing portion is increased so as to narrow the passage area in the piping.

According to another aspect of the present invention,

Compressing the at least one compression section disposed at least at one end;

Determining an operation region of the compression section as a flow rate and a pressure gage connected to the compression section; And

And adjusting a pressure using a pressure regulator provided on an outlet pipe side of the compression unit to prevent backflow when a surge occurs in the compression unit.

In one embodiment, the pressure regulator includes an opening / closing part rotatably installed in the pipe, a driving part connected to the opening / closing part, and a control part transmitting a driving signal to the driving part, Providing a driving force to the opening and closing part provided in the pipe from the driving part, and rotating the opening and closing part such that a passage area in the pipe is narrowed to prevent a loss in a wake.

As described above, the compression device having the pressure regulating device of the present invention and the pressure regulating method using the pressure regulating device according to the present invention are provided with components for attenuating the downstream pressure from the moment when the flow becomes unstable due to stall or the like in the impeller, diffuser, It is possible to prevent the reverse flow of the flow by causing the reverse pressure gradient to become large so that the pressure becomes similar to that of the wake.

1 is a cross-sectional view illustrating a compression apparatus according to an embodiment of the present invention,
2 is a sectional view taken along a line II-II in Fig. 1,
FIG. 3A is a front view schematically showing a state before the operation of the pressure regulator according to the embodiment of the present invention,
FIG. 3B is a front view schematically showing a state after the pressure regulator of FIG.
FIG. 3C is a side view schematically showing the pressure regulating portion of FIG. 3A,
FIG. 3D is a side view schematically showing the pressure regulating portion of FIG. 3B,
4 is a graph showing a performance curve according to the presence or absence of the pressure regulator,
5A is a front view schematically showing a state before the operation of the pressure regulator according to another embodiment of the present invention,
Fig. 5B is a front view schematically showing the state after the pressure regulator of Fig. 5A is actuated, Fig.
FIG. 5C is a perspective view schematically showing the pressure regulating portion of FIG. 5A,
FIG. 5D is a perspective view schematically showing the pressure regulating portion of FIG. 5B,
6 is a view showing a compression device provided with a pressure control unit according to another embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention is capable of various modifications and various embodiments, and particular embodiments are illustrated in the drawings and described in detail in the detailed description. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

The terms first, second, etc. may be used to describe various elements, but the elements should not be limited by terms. Terms are used only for the purpose of distinguishing one component from another.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises", "having", and the like are used to specify that a feature, a number, a step, an operation, an element, a component, Should not be construed to preclude the presence or addition of one or more other features, integers, steps, operations, elements, parts, or combinations thereof.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Hereinafter, embodiments of a compression apparatus according to the present invention will be described in detail with reference to the accompanying drawings, wherein like reference numerals refer to like or corresponding components, Is omitted.

FIG. 1 is a cross-sectional view illustrating a centrifugal compressor 100 as a compression device according to an embodiment of the present invention, and FIG. 2 is a view as viewed in a direction II-II of FIG.

Referring to FIG. 1, the centrifugal compressor 100 includes an impeller 110, a diffuser 120, a shroud 130, a scroll case 140, and a support plate 150.

The impeller 110 includes a hub 111, a blade 112, and an inducer 113 and has a shape symmetrical about a rotation axis C.

The hub 111 has a shape symmetrical about the rotation axis C and has a shape in which the diameter changes along the direction of the rotation axis C. [ In the first portion 114 having the minimum diameter, the engaging portion 115 is positioned and engages with the driving shaft 160 through the center of the hub 111 with respect to the hub 111. Accordingly, the hub 111 is rotatable together with the drive shaft 160.

The outer surface of the hub 111 located between the first portion 114 having the minimum diameter of the hub 111 and the second portion 116 having the maximum diameter is provided with a plurality of blades 112, And the ducer 113 are spaced apart from each other at equal intervals. At this time, the inducer 113 is relatively positioned in the vicinity of the first portion 114, and the blade 112 is positioned in the vicinity of the second portion 116 relatively.

The impeller 110 is rotated at a high speed around the rotation axis C by an external force transmitted through the rotation of the drive shaft 160 so that the impeller 110 rotates in the direction of the rotation axis C through the hollow portion 131 formed in the shroud 130 To compress the fluid. The static pressure and the dynamic pressure of the fluid increase due to the compression by the impeller 110. Further, the dynamic pressure of the fluid changes to a positive pressure as the fluid passes through the diffuser 120 and the volute 141, leading to an additional positive pressure rise.

The impeller 110 is disposed opposite to the shroud 130 having a shape complementary to the outer edges of the inducer 113 and the blade 112. The second portion of the impeller 110 116 are positioned facing the support plate 150. The impeller 110 is disposed inside the space formed by the coupled shroud 130, the scroll case 140, and the support plate 150.

The shroud 130 is a portion surrounding the impeller 110. A hollow portion 131 is formed in the shroud 130 so that the fluid flows from the outside through the impeller 110 and the fluid pressurized by the impeller 110 flows into the scroll case 140 It also serves as a guide.

The scroll case 140 is located at the outer periphery of the impeller 110. The scroll case 140 includes a bolus 141 formed to flow along the rotational direction of the impeller 110 having an increased flow rate by the impeller 110.

The volute 141 is an empty space in the form of a spiral, and has a cross-sectional area that varies along the circumferential direction. As the width of the cross section of the volute 141 changes, the width of the volute inlet 142 can also vary.

As the fluid flowing inside the volute 141 gradually passes through a wide cross section, the dynamic pressure is changed to a constant pressure. As a result of the above process, the effect of the pressure increase of the centrifugal compressor 100 increases, and the fluid flowing in this manner is collected and sent to the discharge pipe 170 and discharged to the outside of the centrifugal compressor 100.

Although the shroud 130 and the scroll case 140 are integrally formed in this embodiment, the present invention is not limited thereto.

The diffuser 120 includes a diffuser plate 121 and a plurality of vanes 122 disposed on the diffuser plate 121. The diffuser 120 may have a structure in which the diffuser plate 121 and the vane 122 are integrally formed and one side of the vane 122 may be attached to the diffuser plate 121.

A circular opening 123 is formed in the diffuser plate 121 to allow the impeller 110 to be drawn in. A plurality of vanes 122 are formed around the opening 123 in the circumferential direction of the opening 123, Respectively. The diffuser plate 121 is fixed to the shroud 130 irrespective of the rotation of the impeller 110. The present invention is not limited thereto and may be installed to be fixed to the support plate 150. [

The vane 122 has a cross-section in the form of an air foil, but is not limited thereto. Alternatively, the vane 122 may have a cross-section of another structure, such as a wedge shape, with one side being supported by the shroud 130 and the other side being supported by the support plate 150.

Here, in order to increase the voltage loss at the wake and to prevent the surge, a pressure regulator is provided at the outlet of the centrifugal compressor 100 or at each stage of the compressor.

Referring to FIG. 2, the centrifugal compressor 100 passes a fluid through a rotating impeller 110 (FIG. 1) to accelerate and compress the fluid by the centrifugal compressive force of the impeller 110. If the flow rate of the fluid passing through the impeller 110 decreases or the pressure difference between the inlet and outlet of the impeller 110 becomes small, the airflow becomes unstable. Therefore, reverse flow occurs in the passage of the diffuser 120, which causes stall and surge.

When a surge occurs, the pressure of the wake moment becomes higher than the pressure of the current instantaneously, so that a reverse pressure gradient occurs and the flow reversely flows. This may increase the vibration of the centrifugal compressor 100 or may damage the components of the centrifugal compressor 100. This may be caused not only by the centrifugal compressor 100 but also by the equipment for operating the centrifugal compressor 100 Which can cause serious damage to the system.

Accordingly, there is provided a pressure regulator 200 that attenuates the downstream pressure from the time when flow due to stall or the like becomes unstable in the impeller 110 or the diffuser 120. In the present embodiment, the pressure regulator 200 is installed on the side of the pipe 180 where the fluid compressed from the centrifugal compressor 100 is discharged to the outside. The pipe 180 is connected to the bolt 141.

The pressure regulating unit 200 includes an opening / closing unit 210, a driving unit 220, and a controller 230.

The discharge pipe 170 of the centrifugal compressor 100 is provided so as to communicate with the pipe 180 which is a connecting means for sending the compressed fluid to other parts of the compression system. An opening / closing part 210 is installed inside the pipe 180. The opening / closing part 210 is a valve system such as a ring valve. The valve system is preferably a variable valve. The opening / closing part 210 is rotatably installed in the pipe 180.

The opening / closing part 210 is connected to the driving part 220. The driving unit 220 is a device for providing a driving force for rotating the opening / closing unit 210 in the pipe 180, for example, an actuator. The opening and closing part 210 operates in the pipe 180 by the driving force of the driving part 220 so as to change the rotation angle and change the passage area in the pipe 180 through which the fluid flows.

The driving unit 220 is connected to the controller 230. The driving unit 220 can control a driving force of a desired magnitude with respect to the opening / closing unit 210 by an electric signal transmitted from the control unit 230.

FIG. 3A is a front view schematically showing a state before the operation of the pressure regulator 200 according to an embodiment of the present invention, and FIG. 3B is a front view of the state after the pressure regulator 200 of FIG. FIG. 3C is a side view schematically showing the pressure regulating part 200 of FIG. 3A, and FIG. 3D is a side view schematically showing the pressure regulating part 200 of FIG. 3B.

3A to 3D, before the pressure regulator 200 is operated, the opening and closing part 210 has a first diameter D1 and is located in the pipe 180. As shown in FIG.

When the centrifugal compressor (100 of FIG. 1) approaches the surge region, the driving unit 220 receiving the electrical signal from the control unit 230 generates driving force, and the opening / closing unit 210 connected to the driving unit 220 And is rotatable at a predetermined angle within the pipe 180 according to the controlled value. The opening and closing part 210 has a second diameter D2 such that the passage area of the pipe 180 is narrowed when the opening and closing part 210 having a variable ring valve structure rotates. The size of the second diameter D2 is smaller than the size of the first diameter D1.

As a result, the passage through which the fluid flows in the pipe 180 is narrowed, thereby obstructing the flow of the entire flow. As a result, a loss occurs in the wake and the voltage decreases. As such, by causing loss in the wake, the reverse pressure gradient is prevented from becoming large, and the flow does not flow backward.

4 is a graph showing a performance curve according to the experiment of the present applicant according to whether the pressure regulator 200 is installed or not.

Here, the X axis represents the flow of the fluid, and the Y axis represents the pressure rise amount (head).

In the absence of the pressure regulator 200, a surge is generated in the vicinity of the fluid indicated by surge, and is operated only in the solid line portion of the performance curve, so that the operating range of the compression system is limited.

However, when the pressure regulating unit 200 is installed on the side of the pipe 180, the centrifugal compressor 100 can be operated to the dotted line portion or more of the performance curve without generating surge, The operation of the centrifugal compressor 100 is possible.

When the pressure regulator 200 operates, the operation of the centrifugal compressor 100 increases due to a delay in the occurrence of the surge.

5A is a front view schematically showing a state before the operation of the pressure regulator 500 according to another embodiment of the present invention, and FIG. 5B is a front view of the state after the pressure regulator 500 of FIG. FIG. 5C is a perspective view schematically showing the pressure regulating part 500 of FIG. 5A, and FIG. 5D is a perspective view schematically showing the pressure regulating part 500 of FIG. 5B.

5A to 5D, the pressure regulating unit 500 includes an opening / closing unit 510, a driving unit 520, and a control unit 530. The opening / closing part 510 is rotatably installed in the pipe 180 by a driving part 520. The opening and closing part 510 is preferably a variable diaphragm which can change the passage area of the pipe 180 through which the fluid flows. The opening and closing part 510 is not limited to any one as long as it is a circular plate-like variable diaphragm or a shape rotatable on the passage 501 of the pipe 180. [

The opening and closing part 510 is rotatably installed in the pipe 180. For this, the opening / closing unit 510 is connected to the driving unit 520. The driving unit 520 is a power source for providing a driving force for rotating the opening / closing unit 510, and is preferably an actuator for controlling a precise rotation angle of the opening / closing unit 510. The driving unit 520 is controlled by a driving force according to an electrical signal transmitted from the control unit 530.

Before the pressure regulating part 500 is operated, the opening / closing part 510 has a first width W1 and is located in the pipe 180. When the centrifugal compressor (100 in FIG. 1) approaches the surge generating area, the opening / closing part 510 having the variable diaphragm structure driven by the driving part 520 operates.

Accordingly, the opening / closing part 510 is rotated to have the second width W2 so that the passage area in the pipe 180 is narrowed. The second width W2 is larger than the first width W1.

As described above, the opening / closing part 510 occupies a certain area of the passage 501 through which the fluid in the pipe 170 flows, thereby obstructing the flow of the entire flow. Therefore, a loss occurs in the wake and the voltage decreases.

FIG. 6 is a block diagram illustrating a compression apparatus 600 provided with a pressure control unit according to another embodiment of the present invention.

Referring to the drawings, the compression apparatus 600 includes a first compression unit 610 through which a fluid flows, a second compression unit 620 provided at a rear end of the first compression unit 610, And a third compression unit 630 disposed downstream of the second compression unit 620 to discharge the fluid. In this embodiment, the number of compressor stages is three stages, but the number of compression stage stages is not limited as long as it has at least one stage compression stage.

Between the compression units 610 to 630 at each of the stages, a pipe 640 is provided to provide a passage through which a fluid to be compressed flows. At this time, an opening / closing part 610 is installed in the pipe 640. The opening / closing part 610 is a valve system such as a variable ring valve capable of varying the passage area of the pipe 640, or a variable diaphragm.

The opening and closing part 610 is connected to the driving part 620. The driving unit 620 is a power source such as an actuator capable of providing driving force for rotating the opening / closing unit 610. The driving unit 620 controls the driving force according to an electrical signal transmitted from the control unit 630.

The operation of the pressure regulator of the compressor 600 having the above-described configuration is as follows.

When the compressor 600 is driven, the fluid flowing into the first stage compressing section 610 is discharged through the second stage compressing section 620 while being compressed through the third stage compressing section 630.

At this time, the operating area of the compression device 600 is determined by the flow rate and pressure gauge 640. When a surge occurs in the compression device 600, the pressure of the downstream flow instantaneously becomes higher than the pressure of the electric current, so that a reverse pressure gradient occurs and the flow reversely flows.

If the compression device 600 determines that there is a surge area, the control unit 630 transmits an electrical signal to the driving unit 620. The driving unit 620 provides the driving force to the opening / closing unit 610 so that the rotation angle of the opening / closing unit 610 changes in the pipe 640.

Accordingly, the opening / closing part 610 rotates at a predetermined angle in the pipe 640, and the flow of the fluid is blocked while occupying a certain area of the flow area of the fluid in the pipe 640.

As a result, a loss occurs in the wake so that the voltage decreases, and the flow does not flow backward. When it is determined that the compression device 600 is in the normal region by the action of the pressure regulator, the opening / closing part 610 is rotated and operated.

100 ... Centrifugal compressor 110 ... Impeller
111 ... hub 112 ... blade
113 ... Inducer 120 ... Diffuser
130 ... scroll case 140 ... scroll case
141 ... Volute 150 ... Support plate
180 ... piping 200 ... pressure regulator
210 ... opening and closing part 220 ... driving part
230 ... control unit

Claims (10)

An impeller coupled to the rotating shaft and having a plurality of blades,
A shroud surrounding the impeller,
A diffuser located at an outer periphery of the impeller and including a plurality of vanes;
A volute disposed at an outer periphery of the diffuser and forming an area,
And a pipe connected to an outlet of the volute,
And a pressure regulating device provided on the piping side for generating a loss in a downstream flow. The method according to claim 1,
The pressure regulator may include:
An opening / closing unit for varying a passage area in the pipe;
A driving unit connected to the opening and closing unit to rotate the opening and closing unit; And
And a control unit for transmitting a driving signal to the driving unit. 3. The method of claim 2,
Wherein the opening / closing portion is a variable valve provided in the pipe and rotatably installed in a direction in which the inside diameter of the opening / closing portion is reduced so that a passage area in the pipe is narrowed. 3. The method of claim 2,
Wherein the opening / closing portion is a variable diaphragm installed in the pipe and rotatably installed in a direction in which the width of the opening / closing portion is increased so as to narrow the passage area in the pipe. At least one compression section disposed at least in one end; And
And a pressure regulating unit installed at an outlet of the compression unit and generating a loss in a downstream. 6. The method of claim 5,
The pressure regulator may include:
An opening / closing unit for varying a passage area in a pipe connected to the outlet of the compression unit;
A driving unit connected to the opening and closing unit and rotating the opening and closing unit; And
And a control unit for transmitting a driving signal to the driving unit. The method according to claim 6,
Wherein the opening and closing part is provided in the pipe and is a variable valve that is rotatably provided in a direction in which the inner diameter of the opening and closing part is reduced so that the passage area in the pipe is narrowed. The method according to claim 6,
Wherein the opening / closing portion is a variable diaphragm installed in the pipe and rotatably installed in a direction in which the width of the opening / closing portion is increased so that a passage area in the pipe is narrowed. Compressing the at least one compression section disposed at least at one end;
Determining an operation region of the compression section as a flow rate and a pressure gage connected to the compression section; And
And adjusting a pressure using a pressure regulator provided on an outlet pipe side of the compression unit to prevent backflow when a surge occurs in the compression unit. 10. The method of claim 9,
The pressure control unit includes an opening / closing unit rotatably installed in the pipe, a driving unit connected to the opening / closing unit, and a control unit transmitting a driving signal to the driving unit.
Transmitting an electrical signal from the control unit to a driving unit;
Providing a driving force to the opening / closing portion provided in the pipe from the driving portion; And
And rotating the opening and closing part such that a passage area in the pipe is narrowed to prevent a loss in a wake.

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