CN209943200U - Centrifugal compressor and refrigerating unit using same - Google Patents

Abstract

The application discloses centrifugal compressor and use its refrigerating unit, centrifugal compressor includes suction chamber and several water conservancy diversion ribs. Wherein the suction chamber has a suction chamber inlet and a suction chamber outlet, the inner wall of the suction chamber tapering from the suction chamber inlet to the suction chamber outlet. The plurality of flow guide ribs are arranged on the inner wall and extend along the central line direction of the air suction chamber. The centrifugal compressor of the application can rectify the fluid without increasing the cost, thereby reducing the turbulent flow loss of the fluid.

Description

Centrifugal compressor and refrigerating unit using same

Technical Field

The present application relates to the field of refrigeration units, and more particularly to a centrifugal compressor.

Background

The refrigeration unit includes a centrifugal compressor and an evaporator. Generally, the centrifugal compressor is installed above the evaporator with the outlet of the evaporator facing upward and the inlet of the centrifugal compressor facing left/right. A suction duct with a 90 ° bend is therefore provided between the outlet of the evaporator and the inlet of the centrifugal compressor for changing the direction of flow of the fluid from upward to left/right. However, the fluid whose flow direction changes through 90 ° undergoes a velocity deflection, which increases the pressure drop of the fluid, thereby reducing the aerodynamic efficiency of the centrifugal compressor.

SUMMERY OF THE UTILITY MODEL

Exemplary embodiments of the present application may address at least some of the above-mentioned issues.

According to a first aspect of the present application, there is provided a centrifugal compressor characterized by: the centrifugal compressor includes:

a suction plenum having a suction plenum inlet and a suction plenum outlet, an inner wall of the suction plenum tapering from the suction plenum inlet to the suction plenum outlet; and

the air guide ribs are arranged on the inner wall and extend along the direction of the central line of the air suction chamber.

In the centrifugal compressor according to the first aspect, the suction chamber has a truncated cone shape.

In the centrifugal compressor according to the first aspect, the plurality of flow guide ribs are arranged on the inner wall at intervals in a circumferential direction of the suction chamber.

In the centrifugal compressor according to the first aspect, a cross section of each of the plurality of flow guide ribs in a radial direction of the suction chamber is a semi-elliptical shape; wherein the major axis radius A, the minor axis radius B and the diameter D of the suction chamber outlet of the semi-ellipse satisfy:

and is

Wherein D, A and B are in the range of greater than 0, and the major axis radius A, the minor axis radius B, and the diameter D are in millimeters.

The centrifugal compressor according to the first aspect, wherein the number N of the plurality of flow guide ribs and the diameter D satisfy:

wherein the value ranges of D and N are more than 0.

In the centrifugal compressor according to the first aspect, the plurality of flow guide ribs are uniformly arranged on the inner wall in the circumferential direction of the suction chamber.

The centrifugal compressor according to the first aspect further comprises an impeller assembly, and the suction chamber outlet is configured to be connected to an inlet of the impeller assembly.

According to a second aspect of the present application, there is provided a refrigeration unit comprising:

the centrifugal compressor according to the first aspect described above; and

an intake pipe comprising a elbow body having an elbow body inlet and an elbow body outlet, and the elbow body configured to enable fluid to flow from the elbow body inlet into the elbow body in a first direction and to flow from the elbow body outlet out of the elbow body in a second direction;

wherein the elbow body outlet is connected to the suction chamber inlet such that fluid flowing in from the elbow body inlet can flow out from the suction chamber outlet.

According to the refrigerating unit of the second aspect, the air suction pipe further comprises a plurality of elbow flow guide ribs, and the elbow flow guide ribs are arranged on the inner wall of the elbow body and extend along the central line direction of the elbow body.

The refrigeration unit according to the second aspect above, further comprising an evaporator; wherein, the elbow body inlet is used for being connected with the export of evaporimeter.

The centrifugal compressor can rectify fluid without increasing cost, thereby reducing turbulent flow loss of the fluid and keeping pressure drop of the suction chamber unchanged.

Drawings

The features and advantages of the present application may be better understood by reading the following detailed description with reference to the drawings, in which like characters represent like parts throughout the drawings, wherein:

FIGS. 1A-1B are perspective and right-side exploded views, respectively, of a centrifugal compressor and evaporator, respectively, using one embodiment of the present application;

FIG. 2A is a perspective view of the centrifugal compressor of FIG. 1A;

FIG. 2B is an exploded right view of the centrifugal compressor of FIG. 2A;

FIG. 2C is a vertical cross-sectional view of the centrifugal compressor of FIG. 2A;

FIG. 3 is a cross-sectional view of the front housing of FIG. 2B taken in a vertical direction;

FIG. 4A is a partial enlarged view of a dotted line frame of the portion A of FIG. 2A;

FIG. 4B is a radial cross-sectional view of the air guide ribs of FIG. 4A;

FIG. 5A is a cross-sectional view of the suction tube used in FIGS. 1A-1B taken along the vertical direction;

FIG. 5B is a radial cross-sectional view of the elbow guide ribs of FIG. 5A;

FIG. 6 is a cross-sectional view of the front housing and suction tube of the centrifugal compressor of FIG. 1A in an assembled state, taken along the vertical direction;

fig. 7 is a cross-sectional view in a vertical direction in an assembled state using another embodiment of a front housing and a suction pipe of a centrifugal compressor of the present application.

Detailed Description

Various embodiments of the present application will now be described with reference to the accompanying drawings, which form a part hereof. It should be understood that although directional terms, such as "left", "right", "upper", "top", "front", and "rear", are used herein to describe various example structural portions and elements of the present application, these terms are used herein for convenience of description only and are to be determined based on example orientations shown in the accompanying drawings. Because the embodiments disclosed herein can be arranged in a variety of orientations, these directional terms are used for purposes of illustration only and are not to be construed as limiting. In the following drawings, like reference numerals are used for like parts.

FIG. 1A is a perspective view of a centrifugal compressor 106 and an evaporator 108 using one embodiment of the present application; fig. 1B is an exploded view from the right of fig. 1A. Generally, a refrigeration unit includes a compressor, a condenser, a throttling device and an evaporator, which are connected in sequence by a connecting pipeline to form a refrigeration cycle loop, and a centrifugal compressor is a common compressor. Only the evaporator 108, the centrifugal compressor 106 and the suction pipe 120 are shown in fig. 1A and 1B, the suction pipe 120 constituting a connecting conduit between an outlet 132 of the evaporator 108 and an inlet 134 of the centrifugal compressor 106.

As shown in fig. 1A and 1B, the top of the evaporator 108 has an outlet pipe 110, with an outlet 132 of the outlet pipe 110 facing upward. Fluid within the evaporator 108 can exit through the outlet 132 of the outlet tube 110. The centrifugal compressor 106 is arranged above the evaporator 108, and the left side of the centrifugal compressor 106 is provided with an inlet 134 of the centrifugal compressor 106. Fluid can enter the centrifugal compressor 106 through the inlet 134.

The suction duct 120 includes an elbow body inlet 144 and an elbow body outlet 146. The elbow body inlet 144 is connected to the outlet 132 of the evaporator 108 and the elbow body outlet 146 is connected to the inlet 134 of the centrifugal compressor 106, thereby allowing fluid flowing from the evaporator 108 to flow into the centrifugal compressor 106 through the suction line 120.

FIG. 2A is a perspective view of the centrifugal compressor 106 of FIG. 1A; FIG. 2B is an exploded right view of the centrifugal compressor 106 of FIG. 2A; fig. 2C is a vertical sectional view of the centrifugal compressor 106 in fig. 2A to show the connection relationship of the respective components. As shown in fig. 2A-2C, centrifugal compressor 106 includes a housing 202 and an impeller assembly 222, with housing 202 including a forward housing 232 and an aft housing 234. Housing 202 has a cavity 204 extending laterally therethrough. Impeller assembly 222 is disposed within plenum 204 such that plenum 204 is divided into a suction chamber 212 at the left end and a drive plenum 242 at the right end. The inlet 224 of the impeller assembly 222 is connected to the outlet 216 of the suction chamber 212 to allow fluid exiting the suction chamber outlet 216 to enter the inlet 224 of the impeller assembly 222. Drive pocket 242 is used to mount a drive means (not shown) for driving impeller assembly 222.

As an example, in the present application, the pockets in the front housing 232 of the housing 202 form the suction chamber 212 at the left end and the pockets in the rear housing 234 form the drive pockets 242 at the right end. The front housing 232 and the rear housing 234 are connected by fasteners (not shown).

In the present application, the impeller assembly 222 is a two-stage impeller. Specifically, the impeller assembly 222 includes a first impeller 252, a diffuser 254, and a second impeller 256. The first impeller 252, the diffuser 254 and the second impeller 256 are mounted in the pocket 204 by fasteners (not shown). When the centrifugal compressor 106 is operated, the first and second impellers 252 and 256 can rotate about their central axes, thereby compressing fluid. More specifically, fluid enters the first impeller 252 through the inlet 224 of the impeller assembly 222 (i.e., the inlet of the first impeller 252), where the fluid is compressed. The compressed fluid exits the outlet of the first impeller 252 and flows into the diffuser 254. The fluid flowing out of the diffuser 254 enters the second impeller 256 from an inlet of the second impeller 256, and the fluid is compressed again in the second impeller 256. The compressed fluid then exits the outlet of the second impeller 256 (i.e., the outlet of the impeller assembly 222).

Although the present application is described with reference to a two-stage impeller, it will be understood by those skilled in the art that the impeller assembly 222 may be a single-stage impeller, or a multi-stage impeller, such as a three-stage impeller, a four-stage impeller, etc.

Fig. 3 is a cross-sectional view of the front housing 232 of fig. 2B taken along the vertical direction. As shown in FIG. 3, the cavity extends transversely through front housing 232 to form suction chamber 212. Suction chamber inlet 314 is inlet 134 of centrifugal compressor 106. The inner wall 302 of the suction chamber 212 is substantially cylindrical and has a center line X. The diameter of inner wall 302 decreases along centerline X from suction chamber inlet 314 to suction chamber outlet 216, resulting in a frusto-conical shape for suction chamber 212. In an axial cross section of the front housing 232, the inner wall 302 of the suction chamber 212 is rectilinear.

The front housing 232 also includes a plurality of flow guide ribs 304. Several flow guiding ribs 304 are arranged on the inner wall 302 in the circumferential direction of the suction chamber 212 at regular intervals. Each flow guiding rib 304 extends in the direction of the centre line X of the suction chamber 212. In other words, the extensions of the several flow guiding ribs 304 can converge on the center line X.

FIG. 4A is a partial enlarged view of a portion A of the dashed line frame of FIG. 2A; fig. 4B is a radial cross-sectional view of the air guide ribs 304 of fig. 4A to show a specific structure of the air guide ribs 304. As can be seen in fig. 4A and 4B, the radial cross-section of the flow guide ribs 304 is a semi-elliptical shape. Wherein, the major axis radius A, the minor axis radius B and the diameter D of the suction chamber outlet 216 of the semiellipse satisfy:

and is

Furthermore, the number N of flow ribs 304 and the diameter D of the suction chamber outlet 216 satisfy:

both N, A, B and D are greater than 0, and the units of major axis radius A, minor axis radius B, and diameter D are millimeters.

When the fluid from the outlet 132 of the upper portion of the evaporator 108 flows into the suction duct 120, the suction duct 120 deflects the flow of the fluid, i.e., changes the flow from upward to rightward. However, since the arrangement of the refrigerating unit is compact, the transverse distance of the suction pipe 120 and the length of the suction chamber are short, the flow is not effectively rectified, the difference between the direction of the flow entering the impeller assembly 222 and the direction of the central axis of the impeller assembly 222 is large, the intensity of turbulence at the inlet is large, and the turbulence loss is also large. The flow guide ribs 304 disposed on the suction plenum 212 in the present application enable fluid entering the centrifugal compressor 106 to be further redirected prior to entering the impeller assembly 222. Specifically, when the fluid enters the centrifugal compressor 106, the fluid contacts the inner wall 302 of the suction chamber 212 and is guided by the guide ribs 304, so that the direction of the fluid is the same as the axial direction (i.e., the direction of the center line X) of the impeller assembly 222. The direction of the velocity of the fluid away from the inner wall 302 will also tend to be the same as the axial direction of the impeller assembly 222, subject to the direction of the velocity of the fluid in contact with the inner wall. In this way, the flow guide ribs 304 may reduce turbulent flow losses of the fluid by further rectifying the fluid. In addition, the air guide ribs 304 can be integrally cast when the front housing 232 is cast, so that the machining steps are not increased, and the cost is not increased.

FIG. 5A is a cross-sectional view of the suction duct 120 used in FIGS. 1A-1B, taken along a vertical direction, to illustrate the internal structure of the suction duct 120; fig. 5B is a radial cross-sectional view of the elbow guide ribs 512 of fig. 5A to illustrate the structure of the elbow guide ribs 512. As shown in fig. 5A-5B, the suction pipe 120 includes an elbow body 502 and a plurality of elbow guide ribs 512. The elbow body 502 is circular in cross-section and gradually decreases in cross-sectional inner diameter from the elbow body inlet 144 to the elbow body outlet 146, and the elbow body inlet 144 is disposed at a 90 ° angle to the elbow body outlet 146. Specifically, the elbow body inlet 144 is oriented in a vertical direction (i.e., a first direction) and the elbow body outlet 146 is oriented in a horizontal direction (i.e., a second direction). The elbow body outlet 146 has a diameter L. A plurality of elbow flow guiding ribs 512 are uniformly arranged on the inner wall of the elbow body 502 along the circumferential direction of the elbow body 502, and each elbow flow guiding rib 512 extends along the direction of the center line Y of the elbow body 502. The cross-sectional shape of any one radial cross-section of the aspirator tube 120 is similar.

The radial section of the elbow flow guide rib 512 is semi-elliptical. The major axis radius J, the minor axis radius K of the semi-ellipse, and the diameter L of the outlet 506 of the aspirator tube 120 satisfy:

and is

Furthermore, the number M of elbow guide ribs 512 and the diameter L of the outlet 506 of the suction pipe 120 satisfy:

both M, J, K and L are greater than 0, and the major axis radius J, minor axis radius K, and the diameter L of the semi-ellipse are in millimeters.

Under the action of centrifugal force, the fluid flowing through the elbow body 502 enables the inner side pressure of the elbow part of the elbow body 502 to be smaller and the outer side pressure to be larger, and the elbow flow guide ribs 512 arranged on the elbow body 502 can weaken the condition that the inner side pressure of the elbow part is smaller and the outer side pressure is larger, and can inhibit the separation phenomenon of the inner wall surface. In addition, the elbow guide ribs 512 can also effectively reduce secondary flow generated by the action of centrifugal force and gravity in the elbow body 502. In addition, the elbow guide ribs 512 can be integrally cast when the elbow body 502 is cast, so that the cost is not increased while the processing steps are not increased.

Fig. 6 is a cross-sectional view of the front housing 232 and the suction pipe 120 of the centrifugal compressor of fig. 1A in a vertical direction to show a positional relationship between the flow guide ribs 304 on the front housing 232 and the elbow flow guide ribs 512 on the elbow body 502 in an assembled state. As shown in fig. 6, the elbow body outlet 146 is connected to the suction chamber inlet 314. When the front shell 232 and the elbow body 502 are both provided with ribs, the number N of the flow guide ribs 304 is equal to the number M of the elbow flow guide ribs 512, and the radial cross-sectional shapes of the flow guide ribs 304 and the elbow flow guide ribs 512 are the same, so that each of the flow guide ribs 304 can be continuously connected with a corresponding one of the elbow flow guide ribs 512, and thus, continuously extending ribs are formed.

Fig. 7 is a cross-sectional view in the vertical direction of another embodiment using the front housing 232 and suction pipe of the centrifugal compressor of the present application to show the positional relationship between the flow guide ribs 304 on the front housing 232 and the elbow flow guide ribs 712 in the suction pipe 720 in an assembled state. The elbow body 702 of figure 7 is substantially identical to the elbow body 502 of figure 6 and will not be described in detail herein. The main differences are: the elbow body 702 in figure 7 is circular in cross-section and has the same inside diameter in cross-section from the elbow body inlet 704 to the elbow body outlet 706, while the elbow body 502 in figure 6 is circular in cross-section and has a gradually decreasing inside diameter from the elbow body inlet 144 to the elbow body outlet 146. Specifically, the cross-sectional shape of any one radial cross-section of the suction duct 720 is the same.

The intake pipe 720 in fig. 7 can also effectively reduce the secondary flow occurring in the intake pipe 120, and suppress the separation phenomenon of the inner wall surface while reducing the cases where the pressure inside the elbow portion is small and the pressure outside is large.

The reduced elbow body 502 of figure 6 is better able to reduce the amount of swirl generated in the flow and reduce pressure losses as compared to the elbow body 702 shown in figure 7.

Those skilled in the art will appreciate that the air intake duct 120 of the present application can be used with an air intake duct having elbow flow guiding ribs, and can also be used with an air intake duct without elbow flow guiding ribs, both of which can provide a better flow rectifying effect for the fluid and reduce the turbulent loss of the fluid, so as to keep the pressure drop of the air intake duct 120 unchanged.

It will be further understood by those skilled in the art that although the radial cross-sections of the flow guide ribs 304 and the elbow flow guide ribs 512 in the above embodiments of the present application are semi-elliptical, the radial cross-sections of the flow guide ribs 304 may be wing-shaped, drop-shaped, semi-circular, rectangular, trapezoidal, triangular, or arched, and the like, which are all within the scope of the present application.

While only certain features of the application have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the application.

Claims (10)

1. A centrifugal compressor (106), characterized by: the centrifugal compressor (106) comprises:

a suction chamber (212), the suction chamber (212) having a suction chamber inlet (314) and a suction chamber outlet (216), an inner wall (302) of the suction chamber (212) tapering from the suction chamber inlet (314) to the suction chamber outlet (216); and

a plurality of flow guiding ribs (304), the plurality of flow guiding ribs (304) being arranged on the inner wall (302) and extending along a direction of a center line (X) of the suction chamber (212).

2. The centrifugal compressor (106) of claim 1, wherein:

the suction chamber (212) is in the shape of a truncated cone.

3. The centrifugal compressor (106) of claim 2, wherein:

the guide ribs (304) are arranged on the inner wall (302) at intervals along the circumferential direction of the suction chamber (212).

4. The centrifugal compressor (106) of claim 3, wherein:

the section of each of the plurality of flow guide ribs (304) in the radial direction of the air suction chamber (212) is semi-elliptical;

wherein the major axis radius A, the minor axis radius B of the semi-ellipse and the diameter D of the suction chamber outlet (216) satisfy:

and is

Wherein D, A and B are in the range of greater than 0, and the major axis radius A, the minor axis radius B, and the diameter D are in millimeters.

5. The centrifugal compressor (106) of claim 4, wherein:

wherein the number N of the plurality of flow guiding ribs (304) and the diameter D satisfy:

wherein the value ranges of D and N are more than 0.

6. The centrifugal compressor (106) of claim 5, wherein:

the guide ribs (304) are uniformly arranged on the inner wall (302) along the circumferential direction of the suction chamber (212).

7. The centrifugal compressor (106) of claim 1, wherein: the centrifugal compressor (106) further comprises:

an impeller assembly (222), the suction chamber outlet (216) for connection with an inlet (224) of the impeller assembly (222).

8. A refrigeration unit, characterized by: the refrigeration unit includes:

-a centrifugal compressor (106) according to any of claims 1-7; and

a gas suction pipe (120,720), the gas suction pipe (120,720) comprising an elbow body (502,702), the elbow body (502,702) having an elbow body inlet (144,704) and an elbow body outlet (146,706), and the elbow body (502,702) being configured to enable fluid to flow from the elbow body inlet (144,704) into the elbow body (502,702) in a first direction and out of the elbow body (502,702) from the elbow body outlet (146,706) in a second direction;

wherein the elbow body outlet (146,706) is connected to the suction chamber inlet (314) such that fluid flowing in from the elbow body inlet (144,704) is able to flow out of the suction chamber outlet (216).

9. The refrigeration unit as set forth in claim 8 wherein: the air intake duct (120,720) further includes:

a plurality of elbow diversion ribs (512,712), the plurality of elbow diversion ribs (512,712) are disposed on an inner wall of the elbow body (502,702) and extend in a direction of a center line (Y) of the elbow body (502,702).

10. The refrigeration unit as set forth in claim 8 wherein: the refrigeration unit further includes:

an evaporator (108);

wherein the elbow body inlet (144,704) is for connection with an outlet (132) of the evaporator (108).

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