KR102104416B1 - Centrifugal compressor - Google Patents

Abstract

The centrifugal compressor according to an embodiment of the present invention includes an impeller that imparts centrifugal force to a fluid through a rotational motion, a scroll that supports the impeller to be rotatable, a shroud arranged to be spaced apart from the impeller, and coupled to the scroll, It is installed on the scroll side of the inner space formed between the scroll and the shroud, and a diffuser plate supporting at least one diffuser vane to guide the flow of the fluid, and a combined surface of the scroll and the shroud formed to have a first thickness It includes a first intermediate member installed on the second intermediate member is formed to have a second thickness and disposed on the engagement surface of the scroll and the diffuser plate.

Description

Centrifugal compressor

Embodiments of the present invention relate to a device, and more particularly to a centrifugal compressor.

Centrifugal compressors are devices that compress fluid by applying centrifugal force to a fluid using an impeller that rotates.

Centrifugal compressors generally include a driving unit that produces a driving force, a gear unit connected to the driving unit, a gearbox in which the gear unit is installed, a rotating shaft inserted into the gearbox and connected to the gear unit, and an impeller connected to the rotating shaft to rotate. And, it may include a scroll for supporting the impeller, and a shroud combined with the scroll to form an inner space through which the fluid flows.

The gap formed between the impeller and the shroud is a factor that greatly affects the efficiency of the centrifugal compressor. When the impeller and the shroud are arranged to have a larger gap than necessary, the compression efficiency of the fluid may be reduced, and conversely, When the impeller and the shroud are disposed close together, vibration due to friction between each other may occur, and further, a large risk of component damage may occur.

On the other hand, Patent Publication No. 2006-0084060 discloses a compressor technology for coating a surface of a shroud adjacent to an impeller with a low hardness material.

Korean Patent Publication No. 2006-0084060. (Released on 21.200.200)

The main object of the embodiments of the present invention is to provide a centrifugal compressor capable of adjusting the gap between the impeller and the shroud.

The centrifugal compressor according to an embodiment of the present invention includes an impeller that imparts centrifugal force to a fluid through a rotational motion, a scroll that supports the impeller to be rotatable, a shroud arranged to be spaced apart from the impeller, and coupled to the scroll, It is installed on the scroll side of the inner space formed between the scroll and the shroud, and a diffuser plate supporting at least one diffuser vane to guide the flow of the fluid, and a combined surface of the scroll and the shroud formed to have a first thickness It includes a first intermediate member installed on the second intermediate member is formed to have a second thickness and disposed on the engagement surface of the scroll and the diffuser plate.

Here, the first thickness and the second thickness are variable, and the gap between the impeller and the shroud is variable as the first thickness and the second thickness are adjusted.

Here, the first thickness and the second thickness may be characterized as having a substantially corresponding thickness.

Other aspects, features, and advantages than those described above will become apparent from the following drawings, claims, and detailed description of the invention.

According to the centrifugal compressor according to the embodiment of the present invention as described above, by adjusting the gap between the impeller and the shroud, it is possible to improve the efficiency and performance of the centrifugal compressor while reducing the risk of vibration and breakage. Of course, the scope of the present invention is not limited by these effects.

1 is a partial cross-sectional view schematically showing a centrifugal compressor according to an embodiment of the present invention.
FIG. 2 is a partial cross-sectional view schematically showing an enlarged portion A of FIG. 1.
3 is a partial cross-sectional view schematically showing an enlarged portion B of FIG. 1.
4 is a partial cross-sectional view schematically showing an enlarged portion C of FIG. 1.
5 is a partial cross-sectional view schematically showing a part of the assembly process of the centrifugal compressor of FIG. 1.

The present invention will become apparent with reference to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various different forms, and only the present embodiments allow the disclosure of the present invention to be complete, and the ordinary knowledge in the technical field to which the present invention pertains. It is provided to fully inform the holder of the scope of the invention, and the invention is only defined by the scope of the claims. Meanwhile, the terms used in the present specification are for explaining the embodiments and are not intended to limit the present invention. In this specification, the singular form also includes the plural form unless otherwise specified in the phrase. As used herein, "comprises" and / or "comprising" refers to the components, steps, operations and / or elements mentioned above, the presence of one or more other components, steps, operations and / or elements. Or do not exclude additions. Terms such as first and second may be used to describe various components, but the components should not be limited by terms. The terms are used only to distinguish one component from other components.

1 is a schematic partial cross-sectional view of a centrifugal compressor according to an embodiment of the present invention, FIG. 2 is a schematic partial cross-sectional view showing an enlarged portion A of FIG. 1, and FIG. 3 is an enlarged portion B of FIG. 1 It is a schematic partial cross-sectional view, and FIG. 4 is a schematic partial cross-sectional view showing an enlarged portion C of FIG. 1.

1 to 4, the centrifugal compressor 100 according to the present embodiment includes an impeller 110, a scroll 120, a shroud 130, a diffuser plate 140, and a first intermediate member It has a 150 and the second intermediate member 160.

The impeller 110 is installed in the inner space of the centrifugal compressor 100 to be rotatable at a high speed around the first rotational central axis C1. That is, the impeller 110 may rotate to the center of the rotation shaft 110a installed along the first rotational center axis C1 to impart centrifugal force to the fluid flowing along the inlet passage 105 of the centrifugal compressor 100. have. At this time, the rotating shaft 110a of the impeller 110 is coupled to a scroll 120, which will be described later, by a mechanical seal (not shown) or the like, so that it is rotatable with respect to the scroll 120, but can prevent fluid from leaking to its engaging portion. .

In addition, the impeller 110 may include a plurality of blades 111 formed radially around the rotation shaft 110a. The blades 111 rotate together with the rotation of the impeller 110, and through this, the fluid flowing along the inflow path 105 may be forcibly moved radially.

The scroll 120 supports the impeller 110 to be rotatable, and a volute formed to allow a fluid having an increased flow rate by the impeller 110 therein to flow along the rotational direction of the impeller 110 ( 121). Here, the volute 121 is a helical (spiral) empty space, having a cross section of a width that changes along the circumferential direction, the width of the volute 121 as the width of the cross section of the volute 121 changes Will change.

In more detail, the fluid flowing inside the volute 121 generally undergoes a process in which dynamic pressure changes to static pressure as it passes through a gradually widening section. Through this process, the effect of increasing the pressure of the centrifugal compressor 100 is increased, and the fluids flowing in this way can be collected and guided toward a delivery pipe (not shown) to be discharged outside the centrifugal compressor 100.

The shroud 130 may be arranged to be spaced apart from the impeller 110 at a predetermined distance to be combined with the scroll 120. The above-described scroll 120 and shroud 130 are mutually coupled to form a space for accommodating the impeller 110 and the diffuser plate 140 to be described later. Here, the scroll 120 and the shroud 130 may be mutually coupled to each other by fastening means such as bolts (B).

The diffuser plate 140 may be installed on the scroll 120 side in the transmission flow path P formed between the scroll 120 and the shroud 130, and the fluid discharged from the impeller 110 is volute 121 ) It may be provided with a plurality of diffuser vanes (141) to perform the function of guiding to the side.

The plurality of diffuser vanes 141 are installed to draw a circumference along the circumference around the impeller 110, and are formed to extend in a direction away from the impeller 110. In detail, the diffuser vane 141 has a cross section of an airfoil shape, but is not limited thereto, and may be formed of a cross section of another shape such as a wedge shape. The diffuser vanes 141 may be installed to be rotatable at a predetermined angle around the second rotational center axis C2 as a variable diffuser vane.

Meanwhile, the diffuser plate 140 and the plurality of diffuser vanes 141 may be integrally formed, or may be in the form of a diffuser vane 141 attached to the diffuser plate 140.

Referring to FIG. 2, the first intermediate member 150 is formed to have a first thickness TA, and may be installed on a coupling surface of the scroll 120 and the shroud 130. Due to the presence of the first intermediate member 150, the shroud 130 is engaged with the scroll 120 at a position further away from the impeller 110 than when the first intermediate member 150 is not installed. This means that the gaps (DI, DO) between the impeller 110 and the shroud 130 can be adjusted by adjusting the first thickness TA of the first intermediate member 150. . This configuration and its effect will be described later in more detail.

Referring to FIG. 3, the second intermediate member 160 is formed to have a second thickness TB, and may be installed on a coupling surface of the scroll 120 and the diffuser plate 140. In detail, the second intermediate member 160 may be installed on the seating surface 120a formed to be recessed on the inner surface of the scroll 120. The seating surface 120a may be formed to have a predetermined depth, and the second intermediate member 160 and the diffuser plate 140 may be sequentially installed on the seating surface 120a in a direction toward the shroud 130. You can.

At this time, the thickness of the second intermediate member 160 combined with the second thickness TB and the thickness of the diffuser plate 140 installed on the second intermediate member 160 is to correspond to the depth of the seating surface 120a. Is decided. In addition, a diffuser vane 141 may be installed in a transmission flow path P formed between the shroud 130 and the diffuser plate 140.

The first intermediate member 150 and the second intermediate member 160 are an integral ring installed between the engagement surface of the scroll 120 and the shroud 130 and between the scroll 120 and the diffuser plate 140 ( Ring) type, but the present invention is not limited thereto. That is, the first intermediate member 150 and the second intermediate member 160 may be manufactured in a ring shape and divided into a plurality of pieces to be installed in the centrifugal compressor 100. For example, the first intermediate member 150 and the second intermediate member 160 may be made of two members having an arc shape, and such an arc-shaped member is further divided into two, each consisting of four members. It may be.

The above-described first thickness TA and second thickness TB are variable, and the gap between the impeller 110 and the shroud 130 is adjusted by adjusting the first thickness TA and the second thickness TB. It can be characterized as variable. Next, referring to FIG. 4, the first thickness TA of the first intermediate member 150 and the second thickness TB of the second intermediate member 160, the impeller 110 and the shroud 130 The relationship between the gaps DI and DO will be described.

For convenience of description, a gap formed between the impeller 110 and the shroud 130 and the inflow path 105 adjacent to the gap is defined as the inflow gap DI, and the transmission flow path P and The adjacent gap will be defined as the outflow gap (DO).

In general, the gap formed between the impeller 110 and the shroud 130, the inflow gap DI and the outflow gap DO are design conditions that greatly affect the performance of the centrifugal compressor 100, the inflow gap When the (DI) and the outflow gap DO are formed too large, the efficiency of the centrifugal compressor 100 may be halved.

On the other hand, when the inlet gap DI and the outlet gap DO are formed to be small, friction between the impeller 110 and the shroud 130 may occur when the centrifugal compressor 100 is operated, which causes the centrifugal compressor 100 ) Can greatly increase the vibration. Due to the vibration of the centrifugal compressor 100, when the centrifugal compressor 100 is emergency-stopped or more severe, the inside of the centrifugal compressor 100 may be damaged.

Therefore, it is necessary to combine the impeller 110 and the shroud 130 to have the optimal inflow gap DI and outflow gap DO by avoiding these risk factors, but in general, the inflow gap DI and the outflow gap (DO) has a very small value of 1 mm or less, so the exact gap between the impeller 110 and the shroud 130 may be affected by factors such as manufacturing tolerances, assembly tolerances, deformation of each part, and changes in operating conditions. There have been limitations in predicting values prior to assembly.

To solve the above-described problems, the centrifugal compressor 100 according to an embodiment of the present invention combines the first intermediate member 150 and the second intermediate member 160 with the scroll 120 and the shroud 130, respectively. It is characterized in that it is installed between the surface and the scroll 120 and the diffuser plate 140 to adjust the gap between the impeller 110 and the shroud 130.

Next, with reference to FIG. 5, the assembly process of the centrifugal compressor 100 for determining the thickness of the first intermediate member 150 and the second intermediate member 160 will be described.

5 is a partial cross-sectional view schematically showing a part of the assembly process of the centrifugal compressor of FIG. 1.

5 shows a state in which a wear part AB having a predetermined thickness is attached to a part of the inner surface of the transmission passage P side among the inner surfaces of the shroud 130 adjacent to the impeller 110. The wear portion AB is preferably formed thicker than the inflow gap DI or the outflow gap DO and the wear gap AB is being driven as the centrifugal compressor 100 is tested and driven several times. Except for the thickness corresponding to the outflow gap DO, the remaining portion may be worn.

Graphite may be used as a material of the wear part AB, but embodiments of the present invention are not limited thereto. That is, the wear part AB is a material having excellent heat resistance that does not change physical properties even in an environment of high temperature and high pressure, such as the inside of the centrifugal compressor 100, or the centrifugal compressor 100 while flowing with the fluid inside the centrifugal compressor 100 Any material that does not lower the efficiency of can be constructed with any material.

Meanwhile, the attachment position of the wear part AB according to the embodiment of the present invention is not limited thereto. That is, the wear part AB may be attached to have a predetermined thickness on some inner surfaces adjacent to the inflow path 105 (see FIG. 1) among the inner surfaces of the shroud 130, and also the shroud 130 Of course, it can be attached to any position of the inner surface disposed to face the impeller 110 and a predetermined gap among the inner surfaces. Hereinafter, for convenience of description, the case where the wear part AB is attached to a part of the inner surface of the transmission passage P side of the inner surface of the shroud 130 will be mainly described.

As described above, the outflow gap DO may be changed according to the first thickness TA of the first intermediate member 150. Therefore, when assembling each component of the centrifugal compressor 100, the first intermediate member 150 having various first thicknesses TA is installed on the combined surface of the scroll 120 and the shroud 130, and tested. The minimum value of the outflow gap DO can be measured by measuring the thickness of the wear part AB remaining on the shroud 130 after driving the centrifugal compressor 100.

Accordingly, by installing the plurality of first intermediate members 150 having various first thicknesses TA on the engagement surfaces of the scroll 120 and the shroud 130, the efficiency of the centrifugal compressor 100 is reduced or the impeller is installed. Centrifugal compressor (100) that can maintain the optimal outflow gap (DO) and drive the impeller (110) so as to avoid the risk of component damage due to collision between the (110) and the shroud (130) Can be assembled.

On the other hand, the second intermediate member 160 is installed between the scroll 120 and the diffuser plate 140, it can be formed between the shroud 130 and the diffuser vane 141 due to the first intermediate member 150 It may be formed to have a second thickness (TB) substantially corresponding to the width of the empty space. According to this configuration, the diffuser vane 141 can stably couple with the shroud 130 and the diffuser plate 140 without generating additional gaps on the transmission flow path P.

Description of the configuration and effects for the above-described embodiments are only exemplary, and those skilled in the art will understand that various modifications and other equivalent embodiments are possible therefrom. Therefore, the true protection scope of the present invention should be defined only by the appended claims.

100: centrifugal compressor 130: shroud
105: inlet 140: diffuser plate
110: impeller 141: diffuser vane
110a: rotating shaft 150: first intermediate member
111: blade 160: second intermediate member
120: scroll DI: inflow clearance
120a: Seating surface DO: Outflow clearance

Claims (3)

An impeller that imparts centrifugal force to the fluid through rotational motion;
A scroll supporting the impeller to be rotatable;
A shroud arranged to be spaced apart from the impeller and coupled to the scroll;
A diffuser plate installed on the scroll side of the inner space formed between the scroll and the shroud to support at least one diffuser vane guiding the flow of the fluid;
A first intermediate member formed to have a first thickness and installed on a combination surface of the scroll and the shroud; And
It is formed to have a second thickness and the second intermediate member disposed on the engagement surface of the scroll and the diffuser plate; including, compressor. According to claim 1,
The first thickness and the second thickness are variable, characterized in that the gap between the impeller and the shroud is variable as the first and second thicknesses are adjusted. delete

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