CN111365259A - Centrifugal Compressor and Refrigerant Circulation System with Diffuser Supply Flow Path - Google Patents

Abstract

The invention discloses a centrifugal compressor and a refrigerant circulation system. The centrifugal compressor includes a housing with an accommodating cavity, a main shaft rotatably arranged in the accommodating cavity, a diffuser, a gas thrust bearing and a supply flow channel, the supply flow channel including a diffuser opened on the diffuser and used for supplying gas to the gas. Diffuser supply runners for thrust bearing air supply. The centrifugal compressor of the present invention directly supplies gas to the gas thrust bearing by opening the diffuser supply flow channel on the diffuser, and has a simple structure and convenient processing.

Description

Centrifugal Compressor and Refrigerant Circulation System with Diffuser Supply Flow Path

technical field

The invention relates to the technical field of static pressure gas bearings, in particular to a centrifugal compressor and a refrigerant circulation system with a diffuser supplying flow passage.

Background technique

Due to the advantages of high precision, low friction, low vibration, low noise, long life and no pollution, gas static pressure bearings are widely used in centrifugal compressors. Aerostatic bearings use external supply pressure to form a gas film for gas lubrication, and their bearing capacity and stiffness increase with the increase of gas supply pressure. However, the disadvantage of the gas static pressure bearing is the phenomenon of "air hammer vibration". The air hammer vibration will cause the bearing to not work normally, and the bearing may be damaged in severe cases. The air hammer vibration phenomenon is directly related to the external pressure supply. The external air supply pressure The internal pressure of the bearing can be changed. The higher the internal pressure, the more serious the vibration of the air hammer.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a centrifugal compressor and a refrigerant circulation system, so as to simplify the air supply passage of the gas bearing of the centrifugal compressor.

A first aspect of the present invention provides a centrifugal compressor, comprising:

a shell with an accommodating cavity;

The main shaft is rotatably arranged in the accommodating cavity;

diffuser;

gas thrust bearings; and

The air supply channel includes a diffuser air supply channel opened on the diffuser and used for supplying air to the gas thrust bearing.

In some embodiments, the centrifugal compressor further includes a gas radial bearing, and the air supply channel further includes a housing supply air channel opened on the housing and used for supplying air to the gas thrust bearing and/or the gas radial bearing.

In some embodiments, the housing supply air channel includes two independent main supply air channel segments, the two main supply air channel segments include a first main supply air channel segment and a second main supply air channel segment, the first main supply air channel segment The gas supply channel section supplies gas to the gas thrust bearing, and the second main supply gas channel section supplies gas to the gas radial bearing.

In some embodiments, the centrifugal compressor includes a thrust disk and two gas thrust bearings disposed on both axial sides of the thrust disk respectively, and the first main supply flow passage section directly supplies gas to one of the two gas thrust bearings, The first main supply runner section communicates with the diffuser supply runner for supplying gas to another gas thrust bearing.

In some embodiments, the housing supply runner includes a main supply runner segment that jointly supplies gas to the gas thrust bearing and the gas radial bearing.

In some embodiments, the housing gas supply channel further includes two branch supply gas channel segments in communication with the main supply gas channel segment, one of the two branch supply gas channel segments in communication with the diffuser supply gas channel for supplying gas to the gas The thrust bearing is supplied with gas, and the other of the two branch gas flow passage sections is supplied with gas to the gas radial bearing.

In some embodiments, the centrifugal compressor further includes a thrust disc and two gas thrust bearings respectively disposed on both axial sides of the thrust disc, and the housing air supply channel further includes three branches communicating with the main supply air channel section. The supply air passage section, the three branch air supply passage sections include the first air supply air passage section, the second air supply air passage section and the third air supply air passage section, and the first air supply air passage section is directed to the two gas thrust bearings. One of the gas thrust bearing is directly supplied with gas, the second gas supply channel section is connected with the diffuser supply gas channel to supply gas to the other gas thrust bearing, and the third gas supply channel section supplies gas to the gas radial bearing.

In some embodiments, the supply pressure of the main supply runner segment is adjustable.

In some embodiments, the air supply pressure of the main air supply runner segment is configured to be adjusted according to the pressure of the containment chamber and/or the vibration of the main shaft.

In some embodiments, the air supply pressure of the main air supply channel segment is configured to be adjusted according to the pressure of the receiving cavity and/or the dynamic balance radial vibration displacement of the main shaft.

In some embodiments, the centrifugal compressor further includes a throttle valve connected to the main supply flow passage section, and the throttle valve acts to control the supply air pressure of the main supply flow passage section.

A second aspect of the present invention provides a refrigerant circulation system, comprising the centrifugal compressor provided in any one of the first aspects of the present invention.

Based on the technical solution provided by the present invention, the centrifugal compressor includes a casing with an accommodating cavity, a main shaft rotatably arranged in the accommodating cavity, a diffuser, a gas thrust bearing and a supply flow channel, the supply flow channel includes a flow channel opened in the expansion cavity A diffuser supply flow passage on the compressor and used to supply gas to the gas thrust bearing. The centrifugal compressor of the present invention directly supplies gas to the gas thrust bearing by opening the diffuser supply flow passage on the diffuser, and has a simple structure and convenient processing.

Other features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the accompanying drawings.

Description of drawings

The accompanying drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the attached image:

FIG. 1 is a schematic diagram of a supply flow passage of a gas thrust bearing according to an embodiment of the present invention;

2 is a schematic diagram of a gas supply flow passage of a gas radial bearing according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of the gas supply flow passages of the gas thrust bearing and the gas radial bearing according to another embodiment of the present invention.

Each reference number represents:

1. Shell; 2. Plug; 3. Thrust disc; 4. Locking screw; 5. Impeller; 6. First gas thrust bearing; 7. Diffuser; 8. Second gas thrust bearing; 9, Gas Radial bearing; 10. Main shaft; 11. Main supply air passage section; 12. Retaining ring.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

The relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the invention unless specifically stated otherwise. Meanwhile, it should be understood that, for the convenience of description, the dimensions of various parts shown in the accompanying drawings are not drawn in an actual proportional relationship. Techniques, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the authorized description. In all examples shown and discussed herein, any specific value should be construed as illustrative only and not as limiting. Accordingly, other examples of exemplary embodiments may have different values. It should be noted that like numerals and letters refer to like items in the following figures, so once an item is defined in one figure, it does not require further discussion in subsequent figures.

For ease of description, spatially relative terms, such as "on", "over", "on the surface", "above", etc., may be used herein to describe what is shown in the figures. The spatial positional relationship of one device or feature shown to other devices or features. It should be understood that spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "above" or "over" other devices or features would then be oriented "below" or "over" the other devices or features under other devices or constructions". Thus, the exemplary term "above" can encompass both an orientation of "above" and "below." The device may also be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptions used herein interpreted accordingly.

As shown in FIG. 1 to FIG. 3 , the centrifugal compressor of the embodiment of the present invention includes:

Shell 1, with an accommodating cavity;

The main shaft 10 is rotatably arranged in the accommodating cavity;

Diffuser 7;

gas thrust bearings; and

The air supply channel includes a diffuser air supply channel 71 opened on the diffuser 7 and used for supplying air to the gas thrust bearing.

In the centrifugal compressor of the embodiment of the present invention, the diffuser supply flow passage 71 is provided on the diffuser 7 to directly supply gas to the gas thrust bearing, and the structure is simple and the processing is convenient.

The compressor of the embodiment of the present invention further includes an impeller 5 connected to the end of the main shaft 10 , a diffuser 7 , a thrust disc 3 , a first gas thrust bearing 6 and a second gas thrust bearing respectively disposed on both axial sides of the thrust disc 3 . The thrust bearing 8 and the gas radial bearing 9 for rotatably supporting the main shaft 10 in the housing 1 . Specifically, the impeller 5 is fixedly connected to the main shaft 10 through the impeller locking screw 4 .

Both the gas thrust bearing and the gas radial bearing of this embodiment include porous media. The supply flow channel circulates the gas to the porous medium.

The air supply channel of this embodiment further includes a housing air supply air channel opened on the housing 1 .

As shown in FIG. 1 and FIG. 2 , the housing air supply air passage in this embodiment includes two main air supply air passage sections, and the two main air supply air passage sections are the first main air supply air passage section 11A and the second main air supply air passage section 11A respectively. In the channel section 11B, the first main supply flow channel section 11A supplies gas to the gas thrust bearing (shown in FIG. 1 ), and the second main supply flow channel section 11B supplies gas to the gas radial bearing 9 (shown in FIG. 2 ). As shown in FIG. 1 , the first main supply flow passage section 11A communicates with the diffuser supply flow passage 71 to supply air to the first gas thrust bearing 6 , and the first main supply flow passage section 11A directly supplies the second gas thrust bearing 8 gas supply. The gas passes through the internal throttle of the thrust bearing and enters into the gap between the thrust bearing and the thrust plate 3 and forms a gas film with pressure, and the gas film acts on the thrust plate 3 to offset the axial force of the system. The gas enters the gap between the gas radial bearing 9 and the main shaft 10 , and forms a wedge-shaped gas film together with the effect of rotational dynamic pressure, which lubricates and supports the main shaft 10 .

Specifically, the diffuser supply flow channel 71 includes a first diffuser supply flow channel and a second diffuser supply flow channel which are arranged perpendicular to each other, wherein the first diffuser supply flow channel is vertically arranged and its end is A plug 2 is provided to prevent gas leakage; the second diffuser supply flow channel is arranged in the axial direction and the opening is arranged on the end face of the diffuser so as to communicate with the main supply flow channel section on the housing 1 .

In this embodiment, two main air supply air passages are respectively set in the housing air supply air passage. The first main air supply air passage segment 11A supplies air to the gas thrust bearing, and the second main air supply air passage segment 11B supplies air to the gas radial bearing. That is to say, the gas thrust bearing and the gas radial bearing are separately supplied with gas, and the gas supply pressures of the two main supply air passage sections are set in an adjustable manner, so as to prevent the vibration of the gas hammer and improve the stability of the system. Moreover, in the centrifugal compressor of this embodiment, the air supply passage is formed by drilling holes on the diffuser 7 and the casing 1, and the structure is simple and the processing is convenient.

As shown in FIG. 3 , in another embodiment, the housing supply flow channel includes a main supply flow channel section 11 , and the main supply flow channel section 11 jointly supplies gas for the gas thrust bearing and the gas radial bearing, so as long as the adjustment is made The air supply pressure of the main air supply air passage section 11 can adjust the air supply pressure of all the bearings, and the adjustment is convenient.

Specifically, as shown in FIG. 3 , the housing air supply flow channel of this embodiment includes two branch supply air channel sections that communicate with the main supply air channel section 11 , and one of the two branch supply air channel sections is connected to the expansion channel section 11 . The compressor supply runners communicate to supply gas to the gas thrust bearing, and the other of the two branch supply runner segments supplies gas to the gas radial bearing 9 .

Since the centrifugal compressor of this embodiment includes two gas thrust bearings, the housing supply flow channel includes three branch supply flow channel sections that communicate with the main supply flow channel section 11 .

The three branch air supply passage sections include a first air supply air passage section, a second air supply air passage section and a third air supply air passage section, and the first air supply air passage section is directed to one gas thrust bearing of the two gas thrust bearings. For direct gas supply, the second gas supply channel section is communicated with the diffuser gas supply channel 71 to supply gas to another gas thrust bearing, and the third gas supply channel section supplies gas to the gas radial bearing 9 .

The air supply pressure of the main air supply air passage section of this embodiment can be set in an adjustable manner. Specifically, the air supply pressure of the main air supply air passage section in this embodiment is adjusted according to the pressure of the accommodating cavity and the vibration of the main shaft. During the operation of the compressor, the air supply pressure of the main air supply passage section can be adjusted according to the pressure of the accommodating chamber and the vibration of the main shaft, so as to adjust the stiffness and bearing capacity of the bearing and prevent the occurrence of air hammer vibration.

In a specific embodiment, the air supply pressure of the main air supply channel section can be adjusted according to the dynamic balance radial vibration displacement of the main shaft.

In some embodiments, the centrifugal compressor further includes a throttle valve connected to the main supply flow passage section, and the throttle valve acts to control the supply air pressure of the main supply flow passage section.

As shown in FIG. 1 , the centrifugal compressor of this embodiment further includes a retaining ring 12 disposed at the end of the gas radial bearing 9 .

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand: The specific embodiments of the invention are modified or some technical features are equivalently replaced; without departing from the spirit of the technical solutions of the present invention, all of them should be included in the scope of the technical solutions claimed in the present invention.

Claims (12)

1. A centrifugal compressor, comprising:

a housing (1) having a receiving cavity;

the main shaft (10) is rotatably arranged in the accommodating cavity;

a diffuser (7);

a gas thrust bearing; and

and the gas supply flow channel comprises a diffuser gas supply flow channel (71) which is arranged on the diffuser (7) and used for supplying gas to the gas thrust bearing.

2. A centrifugal compressor according to claim 1, further comprising a gas radial bearing (9), the gas supply channel further comprising a housing gas supply channel opening on the housing (1) and serving to supply gas to the gas thrust bearing and/or the gas radial bearing (9).

3. The centrifugal compressor according to claim 2, wherein the housing gas supply flow passage comprises two main gas supply flow passage sections (11) provided independently, the two main gas supply flow passage sections comprising a first main gas supply flow passage section (11A) and a second main gas supply flow passage section (11B), the first main gas supply flow passage section (11A) supplying gas to the gas thrust bearing, the second main gas supply flow passage section (11B) supplying gas to the gas radial bearing (9).

4. A centrifugal compressor according to claim 3, comprising a thrust disc (3) and two of said gas thrust bearings respectively disposed on both axial sides of said thrust disc (3), said first main gas supply flow path section (11A) supplying gas directly to one of said two gas thrust bearings, said first main gas supply flow path section (11A) communicating with said gas supply flow path (71) to supply gas to the other gas thrust bearing.

5. A centrifugal compressor according to claim 2, wherein the housing gas supply channel comprises a main gas supply channel section (11), the main gas supply channel section (11) supplying gas to both the gas thrust bearing and the gas radial bearing (9).

6. The centrifugal compressor according to claim 5, wherein the housing gas supply passage further comprises two branch gas supply flow path sections communicating with the main gas supply flow path section (11), one of the two branch gas supply flow path sections communicating with the diffuser gas supply flow path (71) to supply gas to the gas thrust bearing, and the other of the two branch gas supply flow path sections supplying gas to the gas radial bearing (9).

7. The centrifugal compressor according to claim 5, wherein the centrifugal compressor further comprises a thrust disk (3) and two of the gas thrust bearings respectively disposed at axial both sides of the thrust disk (3), the housing gas supply passage further comprises three branch gas supply flow passage sections communicated with the main gas supply flow passage section (11), the three branch gas supply flow passage sections comprise a first branch gas supply flow passage section, a second branch gas supply flow passage section and a third branch gas supply flow passage section, the first branch gas supply flow passage section directly supplies gas to one of the two gas thrust bearings, the second branch gas supply flow passage section is communicated with the diffuser gas supply flow passage (71) to supply gas to the other gas thrust bearing, and the third branch gas supply flow passage section supplies gas to the gas radial bearing.

8. A centrifugal compressor according to any one of claims 3 to 7, characterized in that the supply pressure of the main supply flow channel section (11) is adjustably set.

9. A centrifugal compressor according to claim 8, characterized in that the supply air pressure of the main supply flow channel section (11) is configured to be adjusted in dependence of the pressure of the receiving chamber and/or the vibration of the main shaft.

10. A centrifugal compressor according to claim 8, characterized in that the supply air pressure of the main supply flow channel section (11) is configured to be adjusted in dependence of the pressure of the receiving chamber and/or the main shaft dynamic balance radial vibration displacement.

11. A centrifugal compressor according to claim 8, further comprising a throttle valve connected to the main gas supply channel section (11), the throttle valve acting to control the gas supply pressure of the main gas supply channel section (11).

12. A refrigerant circulation system comprising a centrifugal compressor according to any one of claims 1 to 11.

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