KR20190084383A - Compressor housing with piping for recirculating process gas - Google Patents

Abstract

The present invention relates to a compressor housing configured to recirculate a working fluid to prevent influences on efficiency of a compressor while securing an operation area of a compressor. According to the present invention, the working fluid is recirculated along a recirculation pipe, and the working fluid can be prevented from being recirculated all the time by a check valve. A flow rate is supplemented by the recirculated working fluid even when a flow rate of a working fluid introduced into the compressor is reduced, thereby maintaining an inlet angle and securing the operation area of the compressor. Moreover, the check valve is mounted on the recirculation pipe to prevent the working fluid from being recirculated all the time. Therefore, optimal efficiency of the compressor can be prevented from being changed by the recirculated working fluid.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a compressor housing having a piping for recirculating a working fluid,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compressor housing, and more particularly, to a structure of a compressor housing having a pipe for recirculating working fluid to secure an operating region of the compressor.

The operating range of the compressor is determined by the number of revolutions of the impeller and the flow rate of the working fluid. However, there is a range of the upper and lower limits of the flow rate that can be operated for a specific rotational speed condition. The upper limit of the flow rate is a restriction according to the maximum flow rate of the working fluid which is allowed to prevent the choke phenomenon. The lower limit of the flow rate is a restriction on the minimum flow rate of the working fluid that is allowed to prevent the machine from operating safely due to surge phenomenon.

1 is a graph showing an operation region of a compressor. The operation region (1) corresponds to an area between a region in which a surge phenomenon can occur and an area in which a choke phenomenon can occur. The surge line 2 connects the points where the surge starts to occur according to the rotational speed of the impeller and the choke line 3 has choke phenomenon according to the rotational speed of the impeller It is a line that connects the points that are connected. The operation region 1 corresponds to an area between the surge line 2 and the choke line 3. [ The maximum efficiency line (4) represents the operating condition in which the maximum efficiency can be obtained according to the rotational speed of the impeller in the operation region.

However, in a compressor designed to have an operation region as shown in FIG. 1, the actual operation region may be different from the operation region designed by the inlet angle of the working fluid flowing into the impeller. Reference is made to Fig. 2 to describe the operating angle of the working fluid.

2 is a side view of the impeller provided in the compressor. The operating fluid 13a is drawn into the central portion of the impeller by the high rotational force of the impeller 10. [ However, since the impeller 10 rotates, the working fluid 13b is drawn in a direction in which the working fluid 13b is inclined to the blade 12 of the impeller due to the relative speed. The angle formed between the working fluid 13b drawn in accordance with the relative speed and the rotating shaft 11 of the impeller is defined as a drawing angle 14.

3 shows the working fluid flowing in the blades of the impeller according to the inlet angle. The working fluid 15b flows along the surface of the blade 12 when the working fluid 15a is drawn so as to have an appropriate inlet angle 16 to the blade 12. [ In this case, since no peeling occurs between the blade 12 and the working fluid 15b, the compressor is operable in the designed operation region.

On the other hand, when the working fluid 17a is drawn into the blade 12 at a pull-in angle 18 larger than the proper pull-in angle 16, the working fluid 17b may peel off the blade 12. If the working fluid 17b and the surface of the blade 12 are peeled off, a surge may be generated even if a working fluid having a flow rate larger than the lower limit of the operating range is introduced, thereby lowering the lower limit of the operating range, Can be narrower than the designed operating range. An increase in the inlet angle of the working fluid may occur when the flow rate of the working fluid entering the impeller is reduced.

In compressors, surges can occur not only in impellers, but also in diffusers, shrouds, and scrolls. Accordingly, the present invention proposes a compressor housing having a pipe for recirculating a working fluid so as to secure an operation region of the compressor.

Korean Patent Registration No. 10-1236884

SUMMARY OF THE INVENTION It is an object of the present invention to provide a compressor housing having a pipe for recirculating a working fluid so as to secure an operating region of the compressor.

Another object of the present invention is to provide a compressor housing that recirculates the working fluid so as not to affect the efficiency of the compressor.

The problems of the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

According to an aspect of the present invention, there is provided a compressor housing including: an impeller for rotating a working fluid; a shroud for receiving a diffuser for compressing the working fluid and forming an inlet for drawing the working fluid; A scroll formed with the shroud to form a discharge portion for discharging the working fluid; A plurality of first holes formed at equal intervals on one side of the inlet portion; A plurality of second holes formed in at least one of a vicinity of the impeller, a vicinity of the diffuser, and the discharge portion; And a recirculation pipe for recirculating a part of the working fluid so as to flow in the plurality of second holes and to flow out of the plurality of first holes, wherein the recycling pipe comprises: a circular part spaced apart from the inlet part; A first connection part connecting the plurality of first holes and the circular part; And a second connection portion connecting the plurality of second holes and the circular portion.

Other specific details of the invention are included in the detailed description and drawings.

The embodiments of the present invention have at least the following effects.

According to the present invention, even if the flow rate of the working fluid drawn into the compressor is reduced, the insufficient flow rate is supplemented by the recirculating working fluid, so that the inlet angle of the working fluid drawn into the blade can be maintained and the lower limit of the operating range of the compressor can be maintained And the compressor can be operated in the designed operation area.

According to the present invention, the working fluid recirculating through the holes formed at regular intervals in the inlet portion can be evenly introduced into the inlet portion. Therefore, it is possible to prevent the non-uniform flow of the working fluid flowing to the inlet portion by the working fluid drawn into the inlet portion through the recirculation pipe.

According to the present invention, since the check valve is installed in the recirculation pipe, it is possible to prevent the working fluid from being always recirculated from the scroll to the inlet. That is, the flow rate of the working fluid drawn into the inlet portion is reduced, and the working fluid is recirculated only when the difference between the pressure of the working fluid passing through the scroll and the pressure of the working fluid passing through the inlet exceeds the reference value. Therefore, when the compressor is operated at maximum efficiency, the working fluid is not recirculated, and the maximum efficiency of the compressor can be prevented from being changed by the recirculating working fluid.

Further, according to the present invention, since the working fluid is recirculated through the holes formed in the vicinity of the impeller, the diffuser, and the discharging portion, it is possible to prevent surges occurring in various portions of the compressor housing.

The effects according to the present invention are not limited by the contents exemplified above, and more various effects are included in the specification.

1 is a graph showing an operation region of a compressor.
2 is a side view of the impeller provided in the compressor.
3 shows the working fluid flowing in the blades of the impeller according to the inlet angle.
4 is an exploded perspective view of the compressor.
5 is a perspective view of a compressor housing according to an embodiment of the present invention.
6 is a schematic diagram illustrating a plurality of second holes of a compressor housing in accordance with an embodiment of the present invention.
Figure 7 is a schematic diagram illustrating the recirculating working fluid in a compressor housing in accordance with an embodiment of the present invention.
8 illustrates the principle of operation of a check valve in a compressor housing according to an embodiment of the present invention.
9 is a schematic view of a compressor housing according to another embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

Unless defined otherwise, all terms (including technical and scientific terms) used herein may be used in a sense commonly understood by one of ordinary skill in the art to which this invention belongs. Also, commonly used predefined terms are not ideally or excessively interpreted unless explicitly defined otherwise.

The terminology used herein is for the purpose of illustrating embodiments and is not intended to be limiting of the present invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. The terms " comprises "and / or" comprising "used in the specification do not exclude the presence or addition of one or more other elements in addition to the stated element.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

4 is an exploded perspective view of the compressor. The compressor generally includes a driving unit (not shown) for producing a driving force, a gear unit (not shown) connected to the driving unit, a gear box (not shown) in which the gear unit is installed, A scroll 23 that supports the impeller 21 and an operating fluid that is discharged from the impeller 21 is guided to the scroll 23 through a drive shaft (not shown) connected to the drive shaft, And a diffuser 22 having a plurality of vanes formed to surround the impeller 21. And a shroud 24 in engagement with the scroll 23 to form an interior space through which the fluid flows.

The impeller 21 functions to transfer rotational kinetic energy to the working fluid to increase the speed of the working fluid. The impeller 21 has a plurality of blades 2101 for assisting the movement of the working fluid and transmitting energy to the working fluid. The impeller 21 rotates the blade 2101 to transmit kinetic energy to the sucked working fluid.

When the working fluid is introduced into the blade of the impeller at a suitable inlet angle, the designed operating range of the compressor can be secured in the actual operating range. If the flow rate of the working fluid entering the impeller is reduced, the working fluid may enter the impeller blade at a larger inlet angle than the proper inlet angle, which increases the lower limit of the operating area, Can be.

The structure of the compressor housing designed to secure the designed operation region in the actual operation region in the compressor having the above-described configuration will be described.

5 is a perspective view of a compressor housing according to an embodiment of the present invention. 6 is a schematic diagram illustrating a plurality of second holes of a compressor housing in accordance with an embodiment of the present invention. Figure 7 is a schematic diagram illustrating the recirculating working fluid in a compressor housing in accordance with an embodiment of the present invention. 5 to 7, a compressor housing according to one embodiment includes a shroud 24, a scroll 23, recycle piping 26, 27, 28, and a check valve 29. As shown in FIG.

The shroud 24 may be provided with an inlet portion 25 through which the working fluid is drawn by the rotational force of the impeller. A plurality of first holes 31 may be formed on one side of the lead-in portion 25. In Fig. 5, eight first holes 31 are formed on one side of the lead-in portion. The plurality of first holes 31 may be formed in fewer than eight or more numbers. The plurality of first holes 31 may be equally spaced.

The scroll 23 can be coupled with the shroud 24 to form the discharge portion 30 for discharging the working fluid compressed by the diffuser 22. [ The discharge portion 30 can be formed from the outlet of the diffuser 22 to the outlet of the compressor housing. The working fluid sucked by the impeller 21 rotating at high speed can be discharged through the discharging portion 30 after the speed is gradually decreased and the pressure is raised by the diffuser 22.

The compressor housing according to an embodiment of the present invention may include a plurality of second holes 32 formed in the vicinity of the impeller, in the vicinity of the diffuser, and in the discharge portion. In an embodiment of the present invention, the plurality of second holes 32 are formed in the vicinity of the impeller, the vicinity of the diffuser, and the discharge portion, but may be formed on at least one of the vicinity of the impeller, the vicinity of the diffuser, .

More specifically, the plurality of second holes 32 can be formed in the vicinity of the blades of the impeller so that a part of the working fluid rotating by the impeller can be flowed out. The plurality of second holes 32 may be formed in the vicinity of the inlet of the diffuser and in the vicinity of the outlet of the diffuser so that the working fluid flowing into the diffuser and a part of the working fluid flowing out of the diffuser can flow out. The plurality of second holes 32 may be formed on a surface of the discharge portion 30 facing the inlet portion 25 so that a part of the working fluid inside the scroll can flow out.

The recycle piping 26, 27, 28 is a pipe connecting the plurality of first holes 31 and the plurality of second holes 32 so that the working fluid is recirculated. The recycling piping 26, 27, 28 may be divided into a first connecting portion 26, a circular portion 27, and a second connecting portion 28.

The second connection part (28) is a pipe through which a part of the working fluid flows through the plurality of second holes (32). The working fluid passing around the plurality of second holes 32 can flow naturally into the second connecting portion 28 because the working fluid has a higher pressure than the working fluid passing through the inlet portion 25.

The circular portion 27 is connected to the second connection portion 28 and is formed so as to surround and surround the inlet portion 25. The first connection portion 26 connects the circular portion 27 and the plurality of first holes 31 and is a radially formed pipe.

The working fluid passing through the second connection portion 28 may flow out through the circular portion 27 and the first connection portion 26 and through the plurality of first holes 31 to the inlet portion 25. [ The outflowed working fluid can join the existing working fluid that is drawn into the inlet portion 25 by the impeller and can be sucked into the center portion of the impeller.

Referring to FIG. 7, a portion of the working fluid in the vicinity of the impeller may flow through the second hole, and may flow out through the recirculation pipe to the inlet through the first hole (G1). Also in the vicinity of the diffuser, a portion of the working fluid may flow through the second hole and out through the recirculation line through the first hole to the inlet (G2). At this time, the vicinity of the diffuser may mean the vicinity of the entrance of the diffuser and the exit of the diffuser. Also, a part of the working fluid passing through the scroll may flow through the second hole formed in the discharge portion, and may flow out through the recycle pipe to the inlet portion through the first hole (G3).

Since the working fluid past the recirculation lines 26, 27 and 28 can join the existing working fluid that is drawn into the inlet 25, the flow rate of the existing working fluid entering the inlet 25 is reduced The insufficient flow rate can be supplemented by the recirculating working fluid passing through the recirculation line 26, 27, Accordingly, it is possible to prevent an increase in the inlet angle of the working fluid entering the blade due to the reduction of the flow rate of the working fluid, to prevent the lower limit of the operating range from increasing, have.

Further, the working fluid recirculating through the holes 31 formed at regular intervals in the inlet portion can be uniformly introduced into the inlet portion 25. Therefore, it is possible to prevent the flow of the working fluid from being uneven due to the working fluid flowing into the inlet portion 25 through the recirculation pipes 26, 27, 28.

However, since the pressure of the working fluid passing through the vicinity of the second hole of the plurality is higher than the pressure of the working fluid passing through the inlet portion 25, the working fluid is recirculated in all the operating regions. That is, even when the compressor is operated at the highest efficiency point, the working fluid can be recirculated, which may act as a factor for lowering the efficiency of the compressor.

The check valve 29 is a component for preventing the efficiency of the compressor from being lowered by the recirculating working fluid. In the compressor housing according to the embodiment of the present invention, a plurality of check valves 29 may be mounted on the first connection portion 26. Alternatively, at least one check valve 29 may be mounted on the circular part or the second connection part. A method in which the check valve 29 controls the flow of the working fluid will be described with reference to FIG.

8 shows the operation principle of the check valve. The check valve includes a first panel 2902 and a second panel 2903 formed in a shape corresponding to the inner surface of the hinge shaft 2901 and the first connection portion 26. The first connection part 26 may be divided into a first area 2601 and a second area 2602 by the first panel 2902 and the second panel 2903. [

The first panel 2902 and the second panel 2903 can be mounted on the hinge shaft 2901 so as to rotate only in one direction. That is, the first panel 2902 and the second panel 2903 can not be rotated in the first area 2601 and can be mounted on the hinge shaft 2901 so as to be rotatable only in the second area 2602 .

The first panel 2902 and the second panel 2903 can be mounted on the hinge shaft 2901 so as to have an elastic force capable of returning to the initial position. Only when the pressure of the first region 2601 is higher than the pressure of the second region 2602 by the force of returning the initial position of the first panel 2902 and the second panel 2903 to the initial position, To the second region 2602. In this case,

The working principle of this check valve allows the working fluid to be recirculated only when the pressure of the working fluid passing through the scroll and the pressure of the working fluid passing through the inlet differ by a certain amount or more. That is, the working fluid can be recirculated only when the flow rate of the working fluid passing through the inlet by the check valve decreases, that is, when the working fluid is drawn at a flow rate close to the lower limit. Therefore, since the working fluid is always prevented from being recirculated by the check valve, the efficiency of the compressor can be prevented from being lowered by the recirculating working fluid when the compressor is operated at the highest efficiency point.

9 is a schematic view of a compressor housing according to another embodiment of the present invention. Compared with the compressor housing according to the embodiment shown in FIG. 7, the compressor housing according to another embodiment has a plurality of third holes 42 formed in the vicinity of the diffuser inlet, a plurality of fourth holes 43, and a third connecting portion 41 connecting the plurality of third holes 42 and the plurality of fourth holes 43 with each other.

In a compressor housing a surge may occur not only in the impeller but also in the diffuser, and in a compressor housing according to another embodiment of the present invention, a plurality of third holes 42, a plurality of fourth holes 43, and a third connecting portion 31. [ Since the working fluid passing through the diffuser outlet has a higher pressure than the working fluid passing through the diffuser inlet, some of the working fluid at the diffuser outlet can flow into the diffuser inlet naturally through the third connection when connecting the diffuser outlet to the diffuser inlet.

A portion of the working fluid passing through the diffuser outlet may flow through the fourth hole 43 and out through the third connection 41 through the third hole 42 to the diffuser inlet. In addition, a check valve may be mounted on the third connection part 41 to prevent the working fluid from being always recirculated.

It will be understood by those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

1: operation area 2: surge line
3: choke line 4: maximum efficiency line
10, 21: impeller 11: impeller rotating shaft
12, 2101: blade
13a, 13b, 15a, 15b, 17a, 17b: working fluid
14, 16, 18: inlet angle 22: diffuser
23: Scroll 24: Shurawood
25: inlet portion 26: first connection portion
2601: first region 2602: second region
27: circular portion 28: second connection portion
29: Check valve 2901: Hinge shaft
2902: first panel 2903: second panel
30: Discharge part 31: First hole
32: second hole 41: third connection portion
42: third hole 43: fourth hole

Claims (3)

A compressor housing for accommodating an impeller for rotating a working fluid and a diffuser for compressing the working fluid,
A shroud defining an inlet for receiving the working fluid;
A scroll formed with the shroud to form a discharge portion for discharging the working fluid;
A plurality of first holes formed at equal intervals on one side of the inlet portion;
A plurality of second holes formed in at least one of a vicinity of the impeller, a vicinity of the diffuser, and the discharge portion; And
And a recirculation pipe for recirculating a part of the working fluid so as to flow in the plurality of second holes and flow out of the plurality of first holes,
The recycling pipe
A circular portion spaced apart from the inlet portion;
A first connection part connecting the plurality of first holes and the circular part; And
And a second connection portion connecting the plurality of second holes and the circular portion. The method according to claim 1,
Wherein the recirculation pipe is provided with at least one check valve which is opened or closed according to a flow rate of a working fluid flowing into the inlet. The method according to claim 1,
Further comprising: a plurality of third holes formed in the vicinity of the inlet of the diffuser; and a plurality of fourth holes formed in the vicinity of the outlet of the diffuser,
The recycling pipe
And a third connection portion connecting the plurality of third holes and the plurality of fourth holes such that a working fluid flowing out of the plurality of fourth holes flows into the plurality of third holes.

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