KR20120057687A

KR20120057687A - Turbo compressor

Info

Publication number: KR20120057687A
Application number: KR1020100076600A
Authority: KR
Inventors: 황준현
Original assignee: 엘지전자 주식회사
Priority date: 2010-08-09
Filing date: 2010-08-09
Publication date: 2012-06-07

Abstract

The present invention includes a casing having a refrigerant inlet through which a refrigerant flows in and a refrigerant outlet through which the refrigerant flows out; A drive shaft disposed in the casing to rotate therein; A motor arranged to rotate the drive shaft; A rotating body located inside the casing and connected to be rotated by the drive shaft and having a refrigerant flow hole drilled therein; A first impeller positioned inside the rotating body and compressing the refrigerant to flow into the rotating body when the rotating body rotates; A second impeller located outside the rotating body and compressed by the first impeller upon rotation of the rotating body and compressing the refrigerant passing through the refrigerant flow hole, the flow is more than if the U-shaped return flow path is formed inside the casing The loss is small, and the first impeller and the second impeller may be more compact when the first impeller is installed spaced apart in the longitudinal direction of the drive shaft.

Description

Turbo compressor

The present invention relates to a turbocompressor, and more particularly to a turbocompressor for compressing refrigerant gas in multiple stages.

In general, a turbo compressor includes a drive motor, an impeller rotating by the driving force of the drive motor, and a shroud disposed spaced apart from the wings of the impeller, and the centrifugal force of the impeller accommodated in the shroud to rotate the gas such as a refrigerant (hereinafter, Is a device that sucks and compresses a refrigerant.

When the turbo compressor is provided with a plurality of impellers spaced in the longitudinal direction of the drive shaft in one drive shaft, the refrigerant can be compressed in multiple stages.

As described above, the turbo compressor that compresses the refrigerant in multiple stages includes the refrigerant flowing out in a radial direction of one of the plurality of impellers (hereinafter, referred to as a first impeller) between the plurality of impellers. A return flow path of 'U' shape is formed which guides to the suction side of the 2 impeller).

In the turbo compressor as described above, a return channel is formed between the first impeller and the second impeller to form a return flow path having a 'U' shape, and the refrigerant sucked into the turbo compressor is compressed by the first impeller and then 'U'. The return flow path of the '-' shape is compressed by the second impeller.

WO 2001/98669 (2001.12.27)

Conventional turbo compressors have a problem in that a plurality of impellers are spaced apart in the longitudinal direction of the drive shaft and a 'U'-shaped return flow path is formed between the plurality of impellers, so that the flow loss is large and the volume is designed to be large. .

The present invention has been made to solve the above problems of the prior art, the object of the present invention is to provide a turbo compressor that is highly efficient and compact by minimizing flow loss.

According to an aspect of the present invention, there is provided a turbo compressor comprising: a casing having a refrigerant inlet through which a refrigerant flows in and a refrigerant outlet through which the refrigerant flows out; A drive shaft disposed in the casing to rotate therein; A motor arranged to rotate the drive shaft; A rotating body positioned inside the casing and connected to the rotating shaft by the drive shaft and having a refrigerant flow hole drilled therein; A first impeller positioned inside the rotating body and compressing a refrigerant to flow into the rotating body when the rotating body rotates; And a second impeller positioned outside the rotating body and compressing the refrigerant passing through the refrigerant flow hole after being compressed by the first impeller when the rotating body is rotated.

The rotating body may include a cylindrical portion formed in a hollow cylindrical shape, and a connecting portion connecting the cylindrical portion and the drive shaft.

The plurality of refrigerant flow holes may be formed in the cylindrical portion spaced apart in the circumferential direction.

The cylindrical portion may be longer than the first impeller and the second impeller.

The first impeller may protrude from the inner circumferential surface of the rotating body, and the second impeller may protrude from the outer circumferential surface of the rotating body.

The first impeller and the second impeller may be fixed to the casing.

The rotating body has a diameter larger than the first impeller outer diameter and smaller than the second impeller inner diameter; It may include a connecting portion for connecting the cylindrical portion and the drive shaft.

According to the present invention, the first impeller compresses the refrigerant inside the rotating body, the second impeller compresses the refrigerant outside the rotating body, and the refrigerant compressed by the first impeller passes through the refrigerant flow hole drilled in the rotating body and thus the second impeller. Since the flow through the impeller, the flow loss is less than when the U-shaped return flow path is formed inside the casing, there is an advantage that can be more compact when the first impeller and the second impeller is installed spaced apart in the longitudinal direction of the drive shaft.

1 is a schematic view of a refrigerator to which an embodiment of a turbo compressor according to the present invention is applied;
2 is a partially cutaway cross-sectional view of an embodiment of a turbo compressor according to the present invention.
3 is an enlarged cross-sectional view of a main part of another embodiment of a turbo compressor according to the present invention;
4 is a side view of a rotating body, a first impeller and a second impeller of another embodiment of a turbocompressor according to the invention.

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

1 is a schematic view of a refrigerator to which an embodiment of a turbo compressor according to the present invention is applied.

The refrigerator shown in FIG. 1 includes a turbo compressor 2 for compressing a refrigerant; A condenser 4 on which the refrigerant compressed by the turbo compressor 2 is condensed; An expansion mechanism 6 in which the refrigerant condensed in the condenser 4 is expanded; The refrigerant expanded in the expansion mechanism (6) includes an evaporator (8) and an injection mechanism (10) which are evaporated by heat exchange with cold water supplied from a cold water demand destination (not shown).

The turbo compressor 2 is a centrifugal compressor that allows gas phase refrigerant to pass through an impeller rotating at high speed and applies pressure to the gas phase refrigerant using the centrifugal force.

The turbo compressor (2) is a multi-stage turbo compressor for compressing the refrigerant in multiple stages. The turbo compressor (2) includes a first impeller for primarily compressing the refrigerant evaporated in the evaporator (8) and a second impeller for compressing the refrigerant compressed in the first impeller (2). It includes.

The turbo compressor 2 is formed with an injection port 3 through which the gaseous refrigerant is injected between the first impeller and the second impeller.

The turbo compressor 2 is connected to the evaporator 8 and the suction pipe 12, and is connected to the condenser 4 and the discharge pipe 14.

The condenser 4 may be configured as an air-cooled heat exchanger for exchanging outdoor air with a refrigerant, or may be configured as a water-cooled heat exchanger for exchanging coolant supplied from a cooling tower (not shown) with the refrigerant.

The condenser 4, in the case of a water-cooled heat exchanger, is composed of a shell tubular heat exchanger, and includes a shell 16 through which a refrigerant passes and an inner tube 18 disposed inside the shell and through which cooling water passes.

The condenser 4 is connected to the cooling tower and the cooling water flow path 20. The cooling water flow path 20 is provided with a cooling water pump 22 for pumping the cooling water to circulate the cooling tower and the condenser 4.

The cooling water flow path 20 may include a cooling water inlet flow path 24 connected to allow the cooling water cooled in the cooling tower to enter the condenser 4, and a cooling water discharge flow path 26 connected to the cooling water heated in the condenser 4 to the cooling tower. It includes, the coolant pump 22 is installed in any one of the cooling water inlet flow path 24 and the cooling water outlet flow path 26.

The expansion mechanism 6 consists of a capillary tube or an electromagnetic expansion valve.

The evaporator 8 includes a shell 28 through which the refrigerant compressed by the expansion mechanism 6 passes, and an inner tube 30 disposed inside the shell and through which cold water passes.

The evaporator 8 is connected to the cold water demand destination and the cold water flow path 32, and the cold water flow path 32 is provided with a cold water pump 34 for pumping cold water to circulate the cold water demand destination and the evaporator 8.

Here, the cold water demand destination may be composed of an air handling unit (AHU) that mixes indoor air and outdoor air, heats the mixed air with cold water, and then discharges the indoor air. It may be composed of a fan coil unit (FCU: Fan Coil Unit) to be sucked and heat-exchanged with cold water and discharged to the room, or may be composed of a floor piping unit embedded in the floor of the room.

The cold water flow passage 32 is a cold water inflow passage 36 connected to the cold water passing through the cold water demand destination to the evaporator 8, and a cold water discharge flow passage 38 connected to the cold water cooled by the evaporator 8 to the cold water demand destination. It includes, the cold water pump 34 is installed in any one of the cold water inlet flow path 36 and the cold water outlet flow path (38).

The evaporator 8 is connected with an oil return flow passage 40 for guiding oil accumulated in the evaporator 8 to the suction side of the turbo compressor 2.

The injection mechanism 10 injects the refrigerant condensed in the condenser 4 between the first impeller and the second impeller of the turbo compressor 2, the economizer heat exchanger 42, and the refrigerant injection passage 44. And an economizer expansion mechanism 46.

The economizer heat exchanger 42 is a type of subcooled heat exchanger installed between the condenser 4 and the expansion mechanism 6 to supercool the refrigerant condensed in the condenser 4, and among the refrigerants condensed in the condenser 4. A first flow path 48 that is cooled while a portion passes, and a second flow path 50 that supercools the coolant in the first flow path 48 while the coolant that cools the coolant in the first flow path 48 pass.

The first flow path 48 is a cooling flow path that is supercooled while some of the refrigerant condensed in the condenser 4 passes through and loses heat to the refrigerant passing through the second flow path 50.

The second flow path 50 is an endothermic flow path that deprives heat of the refrigerant passing through the first flow path 48 while the remaining refrigerant that does not flow from the condenser 4 to the first flow path 48 passes.

The refrigerant injection passage 44 guides the refrigerant condensed in the condenser 4 to be injected into the compressor 2 after passing through the second flow passage 50.

The economizer expansion mechanism 46 is a kind of subcooled expansion mechanism that causes the refrigerant condensed in the condenser 4 to expand before entering the economizer heat exchanger 42. It is installed in the refrigerant injection passage 44 to be expanded before passing through the second passage 50.

The economizer expansion mechanism 46 is formed of electronic expansion valves (EEVs) which can adjust the opening degree so as to adjust the amount of the refrigerant according to the operation of the refrigerator.

That is, some of the refrigerant condensed in the condenser 4 is supercooled while passing through the first flow path 48 of the economizer heat exchanger 42.

The remaining refrigerant that does not flow into the first flow passage 48 of the economizer heat exchanger 42 among the refrigerant condensed in the condenser 4 passes through the refrigerant injection flow path 44 and has an economizer expansion mechanism ( 46 is expanded and injected into the injection port 3 of the compressor 2 after taking heat from the refrigerant of the first flow path 48 in the second flow path 50 of the economizer heat exchanger 42.

2 is a partially cutaway sectional view of an embodiment of a turbo compressor according to the present invention.

As shown in FIG. 2, the turbo compressor includes: a casing 60 having a coolant inlet port 52 through which a coolant flows in and a coolant outlet 54 through which the coolant flows out; A drive shaft 70 disposed in the casing 60 to be rotated therein; A motor 80 arranged to rotate the drive shaft 70; A rotating body 90 which is located inside the casing 60 and is rotatably connected by the drive shaft 70 and in which the refrigerant flow hole 88 is perforated; A first impeller 100 positioned inside the rotating body 90 and compressing the refrigerant to flow to the rotating body 90 when the rotating body 90 rotates; A second impeller 110 positioned outside the rotating body 90 and compressed by the first impeller 50 upon rotation of the rotating body 90 and then passing through the refrigerant flow hole 88. do.

The casing 60 is connected to the suction pipe 12 shown in FIG. 1 to the refrigerant inlet 52 and the discharge pipe 14 shown in FIG. 1 to the refrigerant outlet 54.

The casing 60 has a housing 56 in which a space in which the rotating body 90, the first impeller 100, and the second impeller 110 are located is formed, and the refrigerant outlet 54 and the injection port 3 are spaced apart from each other. ), And a suction body 58 coupled with the housing 56 and having a coolant inlet 52 formed therein.

Inside the housing 56, the first shroud 62 surrounds the first impeller 100 and has a gap between the first impeller 100, and the second impeller 110 surrounding the second impeller 110. A second shroud 64 having a gap is disposed between and.

The drive shaft 70 is disposed long in the casing 60 and is connected to the motor 80 through a power transmission member 72 such as a gear.

The rotating body 90 includes a cylindrical portion 92 formed in a hollow cylindrical shape, and a connecting portion 94 connecting the cylindrical portion 92 and the drive shaft 70.

Preferably, a plurality of refrigerant flow holes 88 are formed in the rotating body 90, and a plurality of refrigerant flow holes 88 are formed to be spaced apart in the circumferential direction from the cylindrical portion 92.

The cylindrical portion 92 has a length in the front-rear direction longer than the front-rear length of the first impeller 100 and the length of the front-rear direction of the second impeller 110.

The first impeller 100 is integrally formed on the inner circumferential surface of the rotating body 90 to rotate together with the rotating body 90 when the driving shaft 70 rotates.

The first impeller 100 includes a hub portion protruding from the inner circumferential surface of the rotating body 90, in particular the cylindrical portion 92, and a plurality of blades protruding from the hub portion, the plurality of blades including the first shroud 62. It protrudes to a height having a gap with.

The first impeller 100 is formed such that a plurality of blades are positioned between the hub portion and the cylindrical portion 92.

The second impeller 110 is integrally formed on the outer circumferential surface of the rotating body 90 to be rotated together with the rotating body 90 when the driving shaft 70 rotates.

The second impeller 110 includes a hub portion protruding from the outer circumferential surface of the rotating body 90, in particular the cylindrical portion 92, and a plurality of blades protruding from the hub portion, the plurality of blades including the second shroud 64. It protrudes to a height having a gap with.

The first impeller 100 and the second impeller 110 have a diameter difference due to their formation position, and the inner diameter of the second impeller 110 is formed larger than the outer diameter of the first impeller.

The first impeller 100 and the second impeller 110 are formed to overlap in a radial direction of the rotating body 90 with a cylindrical portion 92 interposed therebetween. That is, the position of the rear end of the first impeller 100 is located behind the tip position of the first impeller 110.

The first impeller 100 and the second impeller 110 divide the cylindrical portion 92 into a region close to the connecting portion 94 and a region far from the connecting portion 94 based on the refrigerant flow hole 88. Protruding from the portion close to the connection portion 94 with respect to the flow hole 88, the refrigerant flow hole 88 of the rotating body 90 is formed in the outer peripheral position of the first impeller 100.

When the drive shaft 70 rotates, the refrigerant is sucked into the first impeller 100 and then '??' Direction and flows in the centrifugal direction of the first impeller 100, and then passes through the refrigerant flow hole 88 of the rotating body 90 to flow out of the cylindrical portion 92, and then the rotating body 90 In the direction parallel to the longitudinal direction of the flow is converted to a right angle, and sucked by the second impeller (110) '??' Direction is flowed in the centrifugal direction of the second impeller (100).

That is, the turbo compressor according to the present embodiment does not have a 'U' shaped return flow path as in the conventional turbo compressor, so that the flow loss is lower than that of the conventional turbo compressor.

Meanwhile, the injection port 3 shown in FIG. 1 is formed in the casing 60, and the injection port 3 is formed at a position where the refrigerant is injected between the casing 60 and the rotating body 90, and the injection port 3. The refrigerant injected into (3) is mixed with the refrigerant passing through the refrigerant flow hole 88 of the rotating body 90 between the casing 60 and the rotating body 90 and then sucked into the second impeller 110. Is compressed.

Hereinafter, the operation of the turbo compressor 2 will be described.

In the turbo compressor 2, when the motor 80 is driven, the drive shaft 70 rotates in association with the motor 80, and the rotating body 90 rotates together with the drive shaft 70.

When the rotating body 90 is rotated, the first impeller 100 located inside the rotating body 90 is rotated together with the rotating body 90 and the second impeller located outside the rotating body 90 ( 110 is rotated together with the rotating body (90).

When the drive shaft 70, the rotation body 90, the first impeller 100, and the second impeller 110 are rotated as described above, the refrigerant in the suction pipe 12 illustrated in FIG. 1 is the casing 60. By the suction force generated in the inside) is sucked into the refrigerant inlet 52, and is sucked into the first impeller 100 through the first impeller 100 and the first shroud (62).

The refrigerant sucked into the first impeller 100 is compressed by the first impeller 100 and then flows toward the inner surface of the cylindrical portion 92 of the rotating body 90, and then the refrigerant flow hole formed in the cylindrical portion 92. Passed through the 88 is injected to the outside of the cylindrical portion (92).

As described above, the refrigerant injected to the outside of the cylindrical portion 920 is sucked into the second impeller 110 through the second impeller 110 and the second shroud 64, and by the second impeller 110. Is compressed.

The refrigerant compressed by the second impeller 110 flows in the radial direction of the second impeller 110, and is discharged to the discharge pipe 14 shown in FIG. 1 through the refrigerant outlet 54.

3 is an enlarged cross-sectional view of an essential part of another embodiment of a turbo compressor according to the present invention, and FIG. 4 is a side view of a rotating body, a first impeller, and a second impeller of another embodiment of the turbo compressor according to the present invention.

In the turbo compressor according to the present embodiment, as shown in FIGS. 3 and 4, the first impeller 100 ′ and the second impeller 110 ′ are fixed to the casing 60 and the first impeller 100 ′. And other configurations and operations other than the second impeller 110 ') are the same as or similar to those of the exemplary embodiment of the present invention, and the same reference numerals are used, and detailed description thereof will be omitted.

The rotating body 90 includes a cylindrical portion 92 whose diameter is larger than the outer diameter of the first impeller 100 'and smaller than the inner diameter of the second impeller 110'; It includes a connecting portion 94 for connecting the cylindrical portion 92 and the drive shaft (70).

That is, the inner circumferential surface of the rotating body is spaced apart from the outer circumferential surface of the first impeller, and the outer circumferential surface is spaced apart from the inner circumferential surface of the second impeller.

In the turbo compressor according to the present embodiment, the first impeller 100 ′ and the second impeller 110 ′ compress the refrigerant by the relative motion generated during the rotation of the rotary body 90. Relative speed ratio is generated between the 100 ') and the second impeller (110'), and when the optimum design of the relative speed ratio, it is possible to design a high low pressure compression ratio.

The first impeller 100 ′ is preferably fixed to the first shroud 62 disposed inside the casing 60 through the connection portion 102, and the second impeller 110 ′ is fixed to the housing 56. It is preferable to be fixed.

The present invention is not limited to the above embodiments, and various implementations can be made within the technical scope of the present invention.

2: compressor 3: injection port
56: housing 58: suction body
60: casing 62: first shroud
64: second shroud 70: drive shaft
80: motor 90: rotating body
92: cylindrical portion 94: connecting portion
100: first impeller 110: second impeller

Claims

A casing having a coolant inlet through which the coolant flows and a coolant outlet through which the coolant flows out;
A drive shaft disposed in the casing to rotate therein;
A motor arranged to rotate the drive shaft;
A rotating body positioned inside the casing and connected to the rotating shaft by the drive shaft and having a refrigerant flow hole drilled therein;
A first impeller positioned inside the rotating body and compressing a refrigerant to flow into the rotating body when the rotating body rotates;
And a second impeller positioned outside the rotating body and compressing the refrigerant passing through the refrigerant flow hole after being compressed by the first impeller upon rotation of the rotating body.

The method of claim 1,
The rotating body includes a cylindrical portion formed in a hollow cylindrical shape, and a connecting portion connecting the cylindrical portion and the drive shaft.

The method of claim 1,
The refrigerant flow hole is a turbo compressor formed in a plurality of cylindrical portion spaced apart in the circumferential direction.

The method of claim 1,
And the cylindrical portion is longer in length than the first impeller and the second impeller.

The method according to any one of claims 1 to 4,
The first impeller protrudes from the inner circumferential surface of the rotating body,
The second impeller protrudes on the outer circumferential surface of the rotary body.

The method according to any one of claims 1 to 4,
Said first impeller and said second impeller being fixed to said casing.

The method according to claim 6,
The rotating body has a diameter larger than the first impeller outer diameter and smaller than the second impeller inner diameter;
Turbo compressor including a connecting portion for connecting the cylindrical portion and the drive shaft.