KR102406229B1 - Process gas sealing system - Google Patents

Abstract

The present invention relates to a system for sealing a working fluid while minimizing thermal deformation that a working fluid exerts on a seal such as a labyrinth seal in a device such as a compressor or a turbine. In the present invention, a hole for discharging a mixed fluid in which a working fluid and a supply fluid are mixed is formed, or a hole for cooling heat conducted to the shaft is formed. According to the present invention, since it is possible to prevent the seal from being thermally deformed by the working fluid, the performance degradation of the sealing system can be prevented, and further, the life expectancy of the sealing system can be increased.

Description

Working fluid sealing system {PROCESS GAS SEALING SYSTEM}

The present invention relates to a system for sealing a working fluid leaking from a rotating body such as an impeller, and more particularly, to a working fluid while minimizing thermal deformation that the working fluid has on a seal such as a labyrinth seal. It relates to a system for sealing the

1 is a perspective view showing the overall appearance of the compressor. The impeller 11 of the compressor is coupled to the shaft 13 and rotates interlockingly. When the impeller 11 rotates at high speed to suck the working fluid into the center of the impeller 11 , the diffuser 12 gradually reduces the speed of the working fluid to convert the reduced speed of the working fluid into pressure.

The high-temperature/high-pressure working fluid generated by the compressor may leak into the region where the bearing 15 and the gear 16 are located along the shaft 13 through the gap even if there is a slight gap. Since oil is usually used for the bearing 15 and the gear 16, when a high-temperature/high-pressure working fluid flows, the function may be damaged. The seal (14, seal) is used to block the leaking of the working fluid through the gap, and a labyrinth seal, dry gas seal (DGS), etc. may be used.

2 shows a cross-sectional view of a compressor to which a labyrinth seal and DGS are applied. The leaking of the working fluid through the gap may be primarily blocked by the labyrinth seal (14a) and secondarily blocked by the DGS (14b). In addition, it is possible to block the leakage of the working fluid by flowing a supply fluid having a relatively higher pressure than the working fluid.

However, in the process of shutting off the high-temperature working fluid, deformation of the seal may occur. Due to the high temperature working fluid, heat can be conducted to the shaft by the heated impeller, and the labyrinth seal can periodically thermally expand/contract due to the influence of the high temperature working fluid. If the seal is thermally deformed, the function of preventing the leaking working fluid may be lost, which may lead to problems such as deterioration of the overall system of the compressor. Such a problem may also occur in a turbine having a similar structure to a compressor.

Accordingly, in the present invention, it is intended to propose a system capable of sealing a working fluid while minimizing thermal deformation on the seal.

Korean Patent Registration No. 100861000

An object of the present invention is to provide a working fluid sealing system capable of minimizing thermal deformation of a seal due to heat conducted through a high temperature working fluid and a shaft.

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

A working fluid sealing system according to an embodiment of the present invention for solving the above problems includes: a shaft rotating about a rotating shaft; a rotating body coupled to the shaft in a direction of the rotation axis and rotating in association with the shaft; a fixture spaced apart from the shaft and the rotating body and disposed to surround the shaft; a seal provided from the rotating body to seal a high-temperature working fluid leaking into a space between the rotating body and the fixed body; a supply fluid inlet hole for introducing a low-temperature supply fluid for mixing with the working fluid; and a mixed fluid outlet hole formed in the fixing body in a radial direction of the shaft to discharge a mixed fluid in which the working fluid and the supply fluid are mixed.

In addition, in the working fluid sealing system according to an embodiment of the present invention for solving the above problems, the fixture includes a supply fluid branch hole having an opening formed on a surface forming the supply fluid inlet hole and a surface facing the surface In addition, the supply fluid may be introduced into an opening formed on a surface forming the supply fluid inlet hole and may flow out through an opening formed on the opposite surface.

In addition, in the working fluid sealing system according to an embodiment of the present invention for solving the above problems, the rotating body and the shaft are fastened by a fastening part, and the shaft is cooled so that heat conducted from the rotating body to the shaft is cooled A supply fluid inlet hole through which the supply fluid flows into the space between the shaft and the fastening part may be included, and the rotating body may include a supply fluid outlet hole through which the supply fluid introduced into the space flows out.

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

According to the embodiments of the present invention, there are at least the following effects.

According to the present invention, since it is possible to prevent the seal from being thermally deformed by the working fluid, the performance degradation of the sealing system can be prevented, and further, the life expectancy of the sealing system can be increased.

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

1 is a perspective view showing the overall appearance of the compressor.
2 shows a cross-sectional view of a compressor to which a labyrinth seal and DGS are applied.
3 shows a cross-sectional view of a working fluid sealing system according to an embodiment of the present invention.
4 shows a cross-sectional view of a working fluid sealing system according to another embodiment of the present invention.
5 shows a cross-sectional view of a working fluid sealing system according to another embodiment of the present invention.
6 shows a cross-sectional view of a working fluid sealing system according to another embodiment of the present invention.

Advantages and features of the present invention and methods of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the art to which the present invention pertains It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.

Unless otherwise defined, all terms (including technical and scientific terms) used herein may be used with the meaning commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in a commonly used dictionary are not to be interpreted ideally or excessively unless clearly defined in particular.

The terminology used herein is for the purpose of describing the embodiments and is not intended to limit the present invention. In this specification, the singular also includes the plural unless specifically stated otherwise in the phrase. As used herein, “comprises” and/or “comprising” does not exclude the presence or addition of one or more other components in addition to the stated components.

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

3 shows a cross-sectional view of a working fluid sealing system according to an embodiment of the present invention. The working fluid sealing system includes a shaft 21, a rotating body 22, a fastening part 23, a fixed body 25, a labyrinth seal 26, a DGS 27, a supply fluid inlet hole 28, and a mixed fluid outlet a hole 29 .

The shaft 21 and the rotating body 22 are fastened by a fastening part 23 . For example, the fastening part 23 may be formed of a bolt so that the shaft 21 and the rotating body 22 are interlocked. A space 24 may be formed between the fastening part 23 and the shaft 21 and the rotating body 22 . When the shaft 21 and the rotating body 22 rotate, this is to minimize the influence of the fastening part 23 by vibration.

The shaft 21 and the rotating body 22 rotate in conjunction with each other. The rotating body 22 may be an impeller of a compressor or a turbine wheel of a turbine. When the rotating body 22 is the impeller of the compressor, the shaft 21 and the impeller may rotate in conjunction with power transmitted from the gear to the shaft 21 . When the rotating body is the turbine wheel of the turbine, the shaft 21 may rotate in conjunction with the turbine wheel by power generated from the turbine wheel.

The fixture 25 is a component for the housing and may be disposed to surround the shaft 21 . The shaft 21 and the rotating body 22 are rotating components, while the stationary body 25 is a stationary component. Therefore, when the shaft 21 and the rotating body 22 rotate, so that friction does not occur with the fixed body 25 , the fixed body 25 is disposed to be spaced apart from the shaft 21 and the rotating body 22 .

The working fluid flowing through the rotating body 22 may leak through a gap generated while the fixed body 25 , the shaft 21 , and the rotating body 22 are spaced apart from each other. When the leaking working fluid 41 leaks to the area where the bearings and gears are located, their functions may be impaired because oil is usually used for the bearings and gears. To prevent this, the labyrinth seal 26 and the DGS 27 serve to seal the leaking working fluid. The bearing and gear are not shown in FIG. 3 , but the positions of the bearing and gear are shown in FIG. 1 , and are located on the right side of the DGS in FIG. 3 .

The labyrinth seal 26 prevents leakage of the working fluid 41 by sequentially installing a plurality of circular sealing strips around the shaft. The labyrinth seal 26 may be formed at one end of the fixture 25 , and is generally formed not to contact the shaft 21 to prevent wear.

The DGS 27 is a seal using dry gas instead of seal oil. The DGS 27 includes a stationary part 27b and a rotating part 27a, and a spiral groove is formed in the rotating part 27a. The spiral groove maintains a gap between the stationary part 27b and the rotating part 27a by locally compressing the dry gas by rotation. Since the pressure of the dry gas is maintained higher than that of the working fluid 41 in the gap between the fixed part 27b and the rotating part 27a, leakage of the working fluid 41 can be prevented.

The supply fluid inlet hole 28 is a hole through which the supply fluid 42 flows in order to prevent the working fluid 41 from leaking. The supply fluid 42 is a fluid of relatively low temperature/high pressure than the working fluid 41 , and flows in the opposite direction to the leaking direction of the working fluid 41 to prevent the working fluid 41 from leaking.

The mixed fluid outlet hole 29 is a hole for discharging the mixed fluid 43 generated by mixing the working fluid 41 and the supply fluid 42 . The mixed fluid outlet hole 29 may be formed in the radial direction of the shaft 21 in the fixture 25 . The mixed fluid outlet hole 29 is preferably formed in a region where the mixed fluid 43 is generated so that the mixed fluid 43 can be discharged. In addition, the mixed fluid outlet hole 29 is preferably formed in a region between the labyrinth seal 26 and the rotating body 22 so as to minimize the effect of the working fluid 41 on the labyrinth seal 26 .

The mixed fluid outlet hole 29 may be formed in plurality. The plurality of mixed fluid outlet holes may be formed radially with respect to the rotation shaft 21a of the shaft. The plurality of mixed fluid outlet holes may be formed on the same plane or on different planes. When the plurality of mixed fluid outlet holes are formed on the same plane, the plurality of mixed fluid outlet holes may be formed at equal intervals or radially to form different intervals. Alternatively, when the plurality of mixed fluid outlet holes are formed on different planes, when the plurality of mixed fluid outlet holes are projected onto any one of different planes, the projected plurality of mixed fluid outlet holes form equal intervals or It may be formed radially to achieve different intervals.

The mixed fluid outlet hole 29 is a hole formed so that the mixed fluid 43 is discharged to the outside. Therefore, it is preferable that the pressure of the opening through which the mixed fluid flows is maintained lower than the pressure of the opening through which the mixed fluid flows.

Since the mixed fluid 43 is discharged along the mixed fluid outlet hole 29 , thermal deformation of the labyrinth seal 26 or the DGS 27 by the working fluid 41 can be prevented. Therefore, the performance degradation of the seal due to thermal deformation is prevented, so that the life expectancy of the sealing system can be increased.

4 shows a cross-sectional view of a working fluid sealing system according to another embodiment of the present invention. The other embodiment of FIG. 4 further includes a supply fluid inlet hole 31 and a supply fluid outlet hole 32 as compared with the embodiment of FIG. 3 .

Although the seal may be directly affected by the high temperature working fluid 41 to be thermally deformed, it may also be indirectly affected to result in thermal deformation.

The rotating body 22 may be heated by the high-temperature working fluid 41 to conduct heat from the rotating body 22 to the shaft 21 . Since the labyrinth seal 26 does not contact the shaft 21 but is disposed at a very small distance from the shaft 21, thermal deformation may occur due to heat conducted to the shaft. In addition, since the DGS 27 is connected to the shaft 21, thermal deformation may occur due to heat conducted to the shaft.

The supply fluid inlet hole 31 and the supply fluid outlet hole 32 cool the heat conducted to the shaft 21 in order to prevent the seal from being indirectly affected by the high temperature working fluid 41 and being thermally deformed. It is a component for

The supply fluid inlet hole 31 may be formed in the shaft 21 so that the supply fluid 44 is introduced into the space 24 between the shaft and the fastening part. In this case, the opening of the supply fluid inlet hole is preferably formed between the mixed fluid outlet hole 29 and the labyrinth seal 26 so that the supply fluid 42 before the mixed fluid 43 is generated flows.

The supply fluid outlet hole 31 may be formed in the rotation body 22 so that the supply fluid 45 introduced into the space 24 between the shaft and the fastening part flows out. At this time, when the rotating body 22 is the impeller of the compressor, the opening of the supply fluid outlet hole is preferably formed toward the working fluid 47 flowing into the rotating body 22 . Since the working fluid 47 flowing into the rotating body has a lower pressure than the working fluid 48 flowing out from the rotating body, when an opening is formed toward the working fluid 47 flowing into the rotating body, the supply fluid 46 is can be easily leaked.

Since the pressure of the supply fluid is relatively higher than the pressure of the working fluid, the supply fluid may be introduced into the supply fluid inlet hole 31 , pass through the internal space 24 , and may be discharged from the supply fluid outlet hole 32 . In addition, since the temperature of the supply fluid is relatively lower than the temperature of the working fluid, the supply fluids 44 , 45 , 46 flowing along the supply fluid inlet hole and the supply fluid outlet hole are conducted to the rotating body 22 and the shaft 21 . heat can be cooled.

The supply fluid inlet hole 31 may be formed in plurality. The plurality of supply fluid inlet holes may be formed to be located in the same direction with respect to the rotation shaft 21a of the shaft, or may be formed to be located in different directions.

The supply fluid outlet hole 32 may also be formed in plurality. The plurality of supply fluid outlet holes may be formed to be located in the same direction with respect to the rotation shaft 21a of the shaft, or may be formed to be located in different directions.

When the supply fluid inlet hole 31 and the supply fluid outlet hole 32 are formed in plurality, they may be formed in the same number or may be formed in different numbers. For example, the number of supply fluid outlet holes may be greater than the number of supply fluid inlet holes in order to facilitate the flow of the supply fluid.

Since the supply fluids 44, 45, and 46 flowing along the supply fluid inlet hole and the supply fluid outlet hole can cool the heat conducted to the rotating body and the shaft, the seal is prevented from being thermally deformed by the heat conducted to the shaft. can do. Furthermore, the effect of heat conducted to the shaft on bearings and gears can also be prevented.

5 shows a cross-sectional view of a working fluid sealing system according to another embodiment of the present invention. Another embodiment of FIG. 5 further includes a supply fluid branch hole 33 compared to the other embodiment of FIG. 4 .

The supply fluid 42 is introduced at a relatively higher pressure than the working fluid 41 , and has a function of preventing leakage of the working fluid 41 , and is introduced at a relatively low temperature than the working fluid 41 , the working fluid 41 . ) to perform a cooling function. For example, if a working fluid of 705°C is introduced, the feed fluid may be introduced at a lower temperature of 205°C.

The supply fluid 42 is mixed with the working fluid 41 to generate the mixed fluid 43 , thereby cooling the working fluid. When the working fluid is cooled, thermal deformation on the seal can be prevented.

The supply fluid branch hole 33 is a component for further enhancing the function of the supply fluid to cool the working fluid. The openings 33a and 33b of the supply fluid branch hole may be formed in a region through which the supply fluid flows and a region through which the working fluid leaks from the rotating body.

Since the supply fluid 42 has a relatively higher pressure than the working fluid 41 , the supply fluid 49 flows toward the working fluid in the supply fluid branch hole 33 . The supply fluid passing through the supply fluid branch hole may be mixed with the working fluid to cool the working fluid.

That is, the supply fluid 49 branched through the supply fluid branch hole is first mixed with the working fluid in the first region 51 to cool the working fluid, and the working fluid is cooled secondarily in the second region 52 , , the working fluid can be cooled over the second time. Therefore, the working fluid is cooled more effectively, so that thermal deformation on the seal can be prevented.

To summarize the flow of the working fluid, the working fluid 41 is primarily cooled by the supply fluid 49 branched by the supply fluid branch hole 33 , and is cooled by the supply fluid flowing along the supply fluid inlet hole 31 . The mixed fluid 43 is formed by the second cooling. The mixed fluid 43 is discharged to the outside along the mixed fluid outlet hole 29 .

The supply fluid branch hole 33 is preferably formed separately from the mixed fluid outlet hole 29 . By separating the branched supply fluid 49 and the mixed fluid 43, the function of the branched supply fluid 49 to cool the working fluid 41 and the function of the mixed fluid 43 to be discharged are not affected by each other. to do

The supply fluid branch hole 33 may be formed in plurality. The plurality of supply fluid branch holes may be formed in the same direction with respect to the rotation shaft 21a of the shaft and have different radii. Alternatively, the plurality of supply fluid branch holes may be formed in different directions with respect to the rotation shaft 21a of the shaft and have the same radius.

6 shows a cross-sectional view of a working fluid sealing system according to another embodiment of the present invention. Another embodiment of FIG. 6 has a different angle at which the supply fluid branch hole 33 is formed as compared with another embodiment of FIG. 5 .

Referring to FIG. 6 , the opening 33b through which the supply fluid flows out from the supply fluid branch hole 33 is formed closer to the shaft 21 than the opening 31a through which the supply fluid flows. When the supply fluid branch hole 33 is formed in this way, since the supply fluid 42 flows in from the top to the bottom in the drawing, the supply fluid 42 can be more easily branched.

The supply fluid 49 branched through the supply fluid branch hole 33 primarily cools the working fluid in the first region 51 and secondarily in the second region 52 .

If you change the angle at which the supply fluid branch hole is formed as shown in FIG. 6, even if the supply fluid air hole is formed with the same radius as the embodiment shown in FIG. can be increased Since the amount by which the feed fluid is branched is increased, the primary cooling of the working fluid can be made more efficiently.

Those of ordinary skill in the art to which the present invention pertains will understand that the present invention may be embodied in other specific forms without changing the technical spirit or essential features thereof. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the following claims rather than the above detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention. do.

11: impeller 12: diffuser
13, 21: shaft 14: seal
14a, 26: labyrinth seal 14b, 27: DGS
15: bearing 16: gear
21a: shaft of rotation 22: rotating body
23: fastening part
24: the space between the fastening part and the shaft and the rotating body
25: fixed body 27a: rotating parts
27b: fixing element 28: supply fluid inlet hole
29: mixed fluid outlet hole
31: supply fluid inlet hole 32: supply fluid outlet hole
33: supply fluid branch hole
33a, 33b: the opening of the supply fluid branch hole
41, 47, 48: working fluid 42, 44, 45, 46, 49: supply fluid
43: mixed fluid 51: first region
52: second area

Claims (6)

a shaft rotating about an axis of rotation;
a rotating body coupled to the shaft in a direction of the rotation axis and rotating in association with the shaft;
a fixture spaced apart from the shaft and the rotating body and disposed to surround the shaft;
a seal provided from the rotating body to seal a working fluid leaking into a space between the rotating body and the fixed body;
a supply fluid inlet hole for introducing a supply fluid for mixing with the working fluid;
a mixed fluid outlet hole formed in the fixing body in a radial direction of the shaft to discharge a mixed fluid in which the working fluid and the supply fluid are mixed; and
a supply fluid inlet hole provided on the shaft to allow the supply fluid to flow into the inner space of the shaft to cool the heat supplied from the rotating body; and
It is provided in the rotating body and is connected to the internal space of the shaft, and includes a supply fluid outlet hole through which the supply fluid flowing into the internal space of the shaft flows out,
Working fluid sealing system. According to claim 1,
A plurality of mixed fluid outlet holes are formed, and the plurality of mixed fluid outlet holes are radially formed with respect to a rotation axis of the shaft. According to claim 1,
The fixture includes a supply fluid branch hole having an opening formed on a surface forming the supply fluid inlet hole and a surface facing the surface,
The supply fluid flows into an opening formed on a surface forming the supply fluid inlet hole and flows out through an opening formed on the opposite surface. 4. The method of claim 3,
An opening through which the supply fluid flows from the supply fluid branch hole is formed to be closer to the shaft than an opening through which the supply fluid flows. 4. The method of claim 3,
The supply fluid branch hole is formed separately from the mixed fluid outlet hole, the working fluid sealing system. According to claim 1,
The rotating body and the shaft are fastened by a fastening part,
The inner space is provided between the shaft and the fastening part,
The supply fluid introduced between the shaft and the fastening part through the supply fluid inlet hole flows out through the supply fluid outlet hole provided in the rotating body,
Working fluid sealing system.

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