KR102113036B1 - A turbo compressor and a turbo chiller including the same - Google Patents

Abstract

The present invention relates to a turbo compressor and a turbo refrigerator including the same.
In the turbo compressor according to an embodiment of the present invention, a casing in which a motor for generating a driving force is disposed; A rotation shaft rotatably installed by driving the motor; An impeller device which is coupled to the rotating shaft and rotates, and includes a plurality of blades for compressing the refrigerant; A wall supporting the outside of the rotating shaft; An installation space formed by the rotating shaft, the wall, and the impeller device; A thrust collar disposed inside the installation space portion and coupled to at least a portion of the outer circumferential surface of the rotating shaft; And a sealing member disposed on an outer circumferential surface of the thrust collar and dividing the installation space into a plurality of spaces.

Description

A turbo compressor and a turbo chiller including the same}

The present invention relates to a turbo refrigerator and a control method thereof.

In general, an air conditioner is a device that cools or heats an indoor space. The air conditioner includes a compressor for compressing a refrigerant, a condenser for condensing the refrigerant discharged from the compressor, an expander for expanding the refrigerant passing through the condenser, and an evaporator for evaporating the refrigerant expanded in the expander.

The turbo freezer includes a compressor that sucks a low pressure refrigerant and compresses it with a high pressure refrigerant, and a condenser, an expansion valve, and an evaporator to drive a refrigeration cycle.

The turbo refrigerator is provided with a centrifugal turbo compressor (hereinafter, a turbo compressor). The turbo compressor acts to discharge the gas in a high pressure state while converting kinetic energy generated by the driving motor into a positive pressure, and rotates by the driving force of the driving motor to compress one or more impellers and the impellers are accommodated. Housing, etc. may be included.

In addition, the turbo compressor may include a thrust bearing for supporting an axial force acting on the rotating shaft while the impeller connected to the rotating shaft rotates at a high speed.

A number of prior art documents are disclosed as follows in relation to the structure of the turbo compressor or the thrust bearing.

1. First Priority Document: "Gas bearing structure of turbo compressor" (Registration No. 10-0296306, Registration Date May 8, 2001)

2. Second Priority Document: "Multi-stage centrifugal compressor with high-pressure fluid injection capacity control device" (Registration No. 10-0814619, registration date March 11, 2008)

According to a conventional turbo compressor, a force directed toward the outside of the compressor acts on the impeller according to the high-speed rotation of the impeller. However, there is a problem in that it is impossible to design a structure or a peripheral structure of a thrust bearing in consideration of this force.

The present invention has been proposed to solve this problem, and an object of the present invention is to provide a turbo compressor and a turbo compressor including the same that can improve the support effect of the thrust bearing.

In the turbo compressor according to an embodiment of the present invention, a casing in which a motor for generating a driving force is disposed; A rotation shaft rotatably installed by driving the motor; An impeller device which is coupled to the rotating shaft and rotates, and includes a plurality of blades for compressing the refrigerant; A wall supporting the outside of the rotating shaft; An installation space formed by the rotating shaft, the wall, and the impeller device; A thrust collar disposed inside the installation space portion and coupled to at least a portion of the outer peripheral surface of the rotating shaft; And a sealing member disposed on an outer circumferential surface of the thrust collar and dividing the installation space into a plurality of spaces.

In addition, a plurality of thrust bearings installed inside the installation space part and spaced apart from both sides of the thrust collar are included.

In addition, the plurality of thrust bearings include: a first bearing spaced apart from the thrust collar in a direction toward the impeller device; And a second bearing spaced apart from the thrust collar in a direction toward the wall.

In addition, the sealing member is characterized in that disposed between the inner surface of the wall and the outer surface of the thrust collar.

In addition, the installation space portion, the first space portion formed on one side of the thrust collar and the sealing member; And a second space portion formed on the other side of the thrust collar and the sealing member.

In addition, the plurality of thrust bearings include: a first bearing disposed in the first space portion; And a second bearing disposed in the second space portion.

In addition, when the rotating shaft and the impeller are rotated, the internal pressure of the first space portion is formed larger than the internal pressure of the second space portion by the refrigerant compressed in the impeller.

In addition, the impeller device, the first impeller coupled to one end of the rotating shaft; And a second impeller coupled to the other end of the rotating shaft, wherein the sealing member is provided on one side of the first impeller and the second impeller, respectively.

In addition, the impeller device includes a first impeller and a second impeller coupled to one end of the rotating shaft, and the sealing member is characterized in that it is disposed at one end of the rotating shaft.

In addition, a turbo refrigerator including the turbo compressor is further included.

According to the present invention, by providing a sealing member on the outer circumferential surface of the thrust collar provided between the two bearings, by causing a pressure difference between the outer pressure and the inner pressure of the thrust collar, the thrust collar can be supported in one direction do.

Particularly, in the process of rotating at a high speed, a force is applied in the outer direction of the compressor. Due to the pressure difference, a force can be applied to the thrust collar in the inner direction of the compressor, so that the stable support of the rotating shaft is possible. have.

In addition, when the turbo compressor is driven by two-stage compression, when the first and second impellers are provided at both ends of the rotating shaft, a sealing member is provided at each impeller side, and when the first and second impellers are provided at one end of the rotating shaft, the above By providing the sealing member only on one side of the rotating shaft, there is an effect that stable support of the rotating shaft is possible.

1 is a cycle diagram showing the configuration of a turbo freezer according to a first embodiment of the present invention.
2 is a cross-sectional view showing the configuration of a turbo compressor according to a first embodiment of the present invention.
3 is an enlarged cross-sectional view of part “A” of FIG. 2.
4 is a view showing the action of the force generated between the driving of the turbo compressor according to the first embodiment of the present invention.
5 is a view showing the configuration of a turbo compressor according to a second embodiment of the present invention.
6 is a view showing the configuration of a turbo compressor according to a third embodiment of the present invention.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. However, the spirit of the present invention is not limited to the presented embodiments, and those skilled in the art to understand the spirit of the present invention may easily propose other embodiments within the scope of the same spirit.

1 is a cycle diagram showing the configuration of a turbo freezer according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view showing the configuration of a turbo compressor according to a first embodiment of the present invention, and FIG. 3 is " A" is an enlarged sectional view.

1 to 3, the turbo refrigerator 10 according to an embodiment of the present invention includes a compressor 20 for compressing a refrigerant and a condenser 30 for condensing the refrigerant compressed in the compressor 20 ), an expansion valve 40 for decompressing the refrigerant condensed in the condenser 30 and an evaporator 50 for evaporating the refrigerant decompressed in the expansion valve 40.

The compressor 20 may include a centrifugal turbo compressor. On the inlet side of the compressor 20, a suction pipe 12 is provided to guide the suction of the refrigerant evaporated from the evaporator 50. And, on the outlet side of the compressor 20, a discharge pipe 14 extending to the condenser 30 is provided.

Cooling water (W1) is introduced and discharged into the condenser 30, and the cooling water is heated by heat exchange with a refrigerant in the process of passing through the condenser 30. Then, cold water (W2) is introduced and discharged into the evaporator 50, and the cold water is cooled by heat exchange with a refrigerant in the process of passing through the evaporator 50.

The expansion valve 40 may include an electronic expansion valve (EEV) capable of opening adjustment. Hereinafter, the structure of the compressor 20 will be described in detail.

In the compressor 20, a casing 100 in which a refrigerant inlet 102 and a refrigerant outlet 104 are formed, a motor 110 provided in the casing 100, and installed inside the casing 100 Power transmission that transmits the driving force of the motor 110 to the rotating shaft 120 by connecting the rotating shaft 120 and the motor 110 and the rotating shaft 120 which can be rotated by the driving force of the motor 110 Member 115 is included.

The refrigerant inlet 102 may be connected to the suction pipe 12, and the refrigerant outlet 104 may be connected to the discharge pipe 14. Further, the power transmission member 115 may include one or more gears.

The compressor 20 is located inside the casing 100 and is coupled to the rotating body 130 rotatably connected by the rotating shaft 120 and the rotating body 130, an impeller that compresses refrigerant ( 135) is further included. The impeller 135 includes a hub coupled to the outside of the rotating body 130 and a plurality of blades coupled to the hub to compress refrigerant. The rotating body 130 and the impeller 135 are combined to be called an "impeller device".

Inside the casing 100, a shroud 142 disposed to surround the impeller 135 is provided.

The refrigerant introduced through the refrigerant inlet 102 flows into a space (a suction space part) spaced between the impeller 135 and the second shroud 142.

The impeller 135 is rotated together with the rotating shaft 120, in the rotation process of the impeller 135, the refrigerant is sucked into the suction space portion of the impeller 135 and compressed, and the compressed refrigerant is the refrigerant outlet 104 ).

The rotating shaft 120 may be coupled through the rotating body 130. At least a portion of the outer circumferential surface of the rotating shaft 120 may be supported by a wall 150 provided inside the casing 100.

In summary, the rotating shaft 120 includes a first part 121 supported by the wall 150 and a second part 123 coupled to the rotating body 130. The first part may be called a "wall support", and the second part may be called a "body joint".

The rotary shaft 120 includes a third part 125 formed between the first part 121 and the second part 123 and supported by bearings 165 and 167. The third part may be referred to as a “bearing support”.

A predetermined space portion 180 is defined by the impeller devices 130 and 135, the wall 150, and the rotating shaft 120. The space portion 180 may be referred to as a “installation space portion” in which the sealing member 170 can be installed. The rotating shaft 120 may be installed to penetrate the installation space portion 180.

In the installation space part 180, a third part 125 of the rotating shaft 120, a thrust collar 160 extending in an outer radial direction of the third part 125, and the thrust collar A plurality of bearings 165 and 167 provided on both sides of the 160 and a sealing member 170 disposed to surround the outer circumferential surface of the thrust collar 160 may be installed.

The "radial direction" may be understood as a direction perpendicular to the extending direction of the rotating shaft 120.

The sealing member 170 is interposed between the inner surface of the wall 150 and the outer surface of the thrust collar 160. In addition, the sealing member 170 may be coupled to the inner surface of the wall 150 or to the outer surface of the thrust collar 160.

The sealing member 170 may be arranged to be spaced apart from the thrust collar 160 when the rotating shaft 120 is rotated, and to contact the thrust collar 160 when the rotating shaft 120 is stopped.

In one example, the sealing member 170, a labyrinth seal (labyrinth seal) is included. In addition, a portion of the sealing member 170 in contact with the thrust collar 160 may have a triangular shape or a sawtooth shape.

The thrust collar 160 may be integrally formed with the rotating shaft 120 or fastened or welded by a separate fixing means.

The installation space 180 may be divided into two sides by the thrust collar 160 and the sealing member 170. Therefore, the installation space portion 180 includes a first space portion 180a formed on one side of the thrust collar 160 and a second space portion 180b formed on the other side of the thrust collar 160. (See FIG. 4).

The one side of the thrust collar 160 is a direction from the thrust collar 160 toward the impeller device 130,135, and the other side of the thrust collar 160 is the wall from the thrust collar 160. It can be understood as a direction toward 150.

The plurality of bearings 165 and 167 include a first bearing 165 spaced apart from one side of the thrust collar 160 and a second bearing 167 spaced apart from the other side of the thrust collar 160. do.

The first bearing 165 and the second bearing 167 are installed to surround the third part 125 of the rotating shaft 120, and when the axial movement of the rotating shaft 120 is axially moved, the surface of the thrust collar 160 It acts to support.

In detail, based on the FIG. 2, when the rotation shaft 120 and the thrust collar 160 move in the right direction, the first bearing 165 may support one surface of the thrust collar 160. In addition, when the rotation shaft 120 and the thrust collar 160 move in the left direction, the second bearing 167 may support the other surface of the thrust collar 160. Here, the "one side" and the "other side" may be opposite sides.

Hereinafter, the operation according to the present embodiment will be briefly described with reference to the drawings.

4 is a view showing the action of the force generated between the driving of the turbo compressor according to the first embodiment of the present invention.

Referring to FIG. 4, when the rotating shaft 120 rotates and the impeller 135 rotates, refrigerant flows into the rotating body 130 and then passes through the refrigerant flow hole 138 to the impeller 135. Will pass through. In this process, the refrigerant is compressed at high pressure.

On the other hand, when the impeller 135 is rotated at a high speed, the impeller 135 receives a force toward the right direction based on the external direction of the compressor 20, that is, FIG. 3. Therefore, the rotating shaft 120 and the thrust collar 160 connected to the impeller 135 receive a force to move in the right direction (first acting force).

On the other hand, by the refrigerant compressed while passing through the impeller 135, the pressure on the impeller 135 side is to form a pressure higher than the pressure on the wall 150 side. In addition, the high-pressure refrigerant may leak into the installation space 180 through the impeller 135.

Therefore, in the installation space portion 180, the pressure of the first space portion 180a, that is, P1 has a pressure value greater than the pressure of the second space portion 180b, that is, P2. As a result, due to the pressure difference between the first space portion 180a and the second space portion 180b, the rotation shaft 120 and the thrust collar 160 receive a force directed toward the left side based on FIG. 3. (Second acting force).

4, the rotational shaft 120 and the thrust collar 160 are moved toward the second bearing 167 by the second acting force.

In summary, in the process of rotating the impeller 135, the first acting force acting in the outer direction of the compressor by the rotational force or centrifugal force of the impeller 135, and acting in the inner direction of the compressor by the high-pressure leakage refrigerant The balance between the second acting forces to be made, the thrust collar 160 has the advantage that can be stably supported between the plurality of bearings (165,167).

5 is a view showing the configuration of a turbo compressor according to a second embodiment of the present invention.

5, the turbo compressor 200 according to the second embodiment of the present invention may be provided to enable two-stage compression of the refrigerant.

In detail, the turbo compressor 200 includes a casing 201 forming a refrigerant inlet 202 and a refrigerant outlet 204, and a motor 210 and the casing 201 provided in the casing 201 It is installed in the rotation shaft 220 that can be rotated by the driving force of the motor 210 is included.

The rotating shaft 220 is coupled to the motor 210, it can be extended to both sides of the motor 210.

The turbo compressor 200 includes a first impeller 230 that is fastened to both ends of the rotating shaft 220 to primarily compress the refrigerant, and a second impeller 235 that is secondaryly compressed. That is, the first impeller 230 may be coupled to and rotated at one end of the rotating shaft 220, and the second impeller 235 may be coupled to and rotated at the other end of the rotating shaft 220.

The turbo compressor 200 further includes a flow pipe 240 that guides the first compressed refrigerant to flow toward the second impeller 235 while passing through the first impeller 230. The refrigerant flowing into the second impeller 235 through the flow pipe 240 may be secondly compressed and then discharged from the refrigerant outlet 204.

In addition, the turbo compressor 200 further includes a wall 250 rotatably supporting both ends of the rotating shaft 220. That is, the wall 250 may be provided on both sides of the rotating shaft 220.

On one side of the turbo compressor 200, an installation space 280 defined by the rotation shaft 220, the first impeller 230, and the wall 250 is included. A sealing member 270 may be installed in the installation space 280. At this time, the installation space part 280 is called a first installation space part.

And, the other side of the turbo compressor 200, the rotating shaft 220, the second impeller 235 and the installation space portion 280 defined by the wall 250 is included. A sealing member 270 may be installed in the installation space 280. At this time, the installation space part 280 is called a second installation space part.

Since the internal structures of the first installation space part and the second installation space part are similar to those described in FIG. 2, detailed descriptions thereof will be omitted.

As described above, in the case of a two-stage turbo compressor having first and second impellers at both ends of the rotating shaft, by applying a thrust bearing structure provided with a sealing member to the first and second impellers, respectively, the rotation shaft or the thrust collar is supported. Can be easily made.

6 is a view showing the configuration of a turbo compressor according to a third embodiment of the present invention.

Referring to FIG. 6, the turbo compressor 20 according to the third embodiment of the present invention may be provided to enable two-stage compression of the refrigerant.

And, for the two-stage compression of the refrigerant, it is characterized in that the first and second impellers are installed at one end of the rotating shaft. Since the structure of the turbo compressor according to the present embodiment is similar to that of the first embodiment, the differences from the first embodiment will be mainly described.

Inside the casing 100, the first shroud 140 and the impeller 135 that guide the refrigerant introduced through the refrigerant inlet 102 to the inside of the rotating body 130 are disposed. A second shroud 142 is provided. In addition, a refrigerant flow hole 138 through which the refrigerant passes is formed in the rotating body 130. A plurality of refrigerant flow holes 138 may be spaced apart from each other on the outer circumferential surface of the rotating body 130.

The turbo compressor 20 further includes a first impeller 330 provided inside the rotating body 130 described in the first embodiment and rotated together with the rotating body 130 when the rotating shaft 120 rotates. Is included.

The first impeller 330 includes a hub coupled to an inner circumferential surface of the rotating body 130 and a plurality of blades protruding from the hub, so that the plurality of blades are spaced apart from the first shroud 140 Is placed. Between the plurality of blades and the first shroud 140, a suction space portion (first suction space portion) that guides suction of the refrigerant to the first impeller 330 is formed.

The refrigerant introduced through the refrigerant inlet 102 flows into the first impeller 330 through the first suction space part and is compressed, and the compressed refrigerant is rotated through the refrigerant flow hole 138 to the rotating body 130 ).

The turbo compressor 20 further includes a second impeller 335 that is provided outside the rotating body 130 and rotates with the rotating body 130 when the rotating shaft 120 rotates.

The second impeller 335 includes a hub coupled to the outer circumferential surface of the rotating body 130 and a plurality of blades protruding from the hub, so that the plurality of blades are spaced apart from the second shroud 142 Is placed. Between the plurality of blades and the second shroud 142, a suction space portion (second suction space portion) that guides suction of the refrigerant to the second impeller 335 is formed.

The first impeller 230 and the second impeller 235 form the same rotational direction.

In the casing 100, an injection port 106 through which a refrigerant is injected is formed. The refrigerant condensed in the condenser 30 may be injected into the injection port 106 through an economizer (not shown).

The refrigerant compressed first in the first impeller 330 passes through the refrigerant flow hole 138 and is mixed with the refrigerant injected into the injection port 106. In addition, the mixed refrigerant may be secondarily compressed by flowing to the second suction space portion of the second impeller 335.

As in the present embodiment, when a plurality of impellers are disposed at one end of the rotating shaft 120, a thrust bearing structure is applied to only one side of the rotating shaft 120 to effectively support the rotating shaft or thrust collar.

10: turbo freezer 20: compressor
30: condenser 40: expansion valve
50: evaporator 100: casing
110: motor 115: power transmission member
120: rotating shaft 130: rotating body
135: impeller 138: refrigerant flow hole
140: first shroud 142: second shroud
150: wall 160: thrust collar
165: first bearing 167: second bearing
170: sealing member 180: installation space
180a: first space portion 180b: second space portion

Claims (10)

A casing in which a motor generating a driving force is disposed;
A rotating body provided rotatably inside the casing and forming a first through hole;
An impeller device coupled to the rotating body and including a plurality of blades for compressing the refrigerant;
A wall fixed to one side of the rotating body and forming a second through hole;
A rotation axis supported on the wall and including a first part penetrating the second through hole and a second part coupled to the rotating body and penetrating the first through hole;
An installation space formed by the rotating shaft, the wall, and the impeller device;
A thrust collar disposed inside the installation space portion and coupled to at least a portion of the outer circumferential surface of the rotating shaft;
A first bearing installed inside the installation space portion and spaced apart from the thrust collar in a direction toward the impeller device;
A second bearing installed inside the installation space part and spaced from the thrust collar in a direction toward the wall;
It is disposed between the inner surface of the wall and the outer surface of the thrust collar, and includes a sealing member that divides the installation space into a plurality of spaces,
When the rotating shaft is stopped, the first and second bearings are spaced apart from both sides of the thrust collar, and the sealing member contacts the outer circumferential surface of the thrust collar,
When the rotating shaft is rotated, the thrust collar is brought into contact with the first bearing or the second bearing so as to be supported between the first and second bearings by a pressure difference inside the installation space portion, and the sealing member and the Thrust collar is eccentric turbo compressor. delete delete delete According to claim 1,
In the installation space,
A first space portion formed on one side of the thrust collar and the sealing member; And
A turbo compressor including a second space portion formed on the other side of the thrust collar and the sealing member. The method of claim 5,
In the first and second bearings,
A first bearing disposed in the first space portion; And
A turbo compressor including a second bearing disposed in the second space portion. The method of claim 5,
When the rotating shaft and the impeller are rotated,
The turbo compressor according to claim 1, wherein the internal pressure of the first space portion is greater than the internal pressure of the second space portion by the refrigerant compressed by the impeller. According to claim 1,
The impeller device,
A first impeller coupled to one end of the rotating shaft; And
A second impeller coupled to the other end of the rotating shaft is included,
The sealing member, a turbo compressor, characterized in that provided on each side of the first impeller and the second impeller. According to claim 1,
The impeller device,
A turbo compressor comprising a first impeller and a second impeller coupled to one end of the rotating shaft, the sealing member being disposed at one end of the rotating shaft. A turbo refrigerator comprising the turbocompressor according to claim 1.

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