Compressor for quantitatively separating conveyed natural gas for self-cooling after primary compression

Abstract

The invention provides a compressor for quantitatively separating conveyed natural gas for self-cooling after primary compression, and belongs to the technical field of compressors. The problems that a motor-gearbox-compressor mode is mostly adopted in a traditional gas compressor complete machine scheme, and meanwhile a bearing lubricating system, a cooling heat dissipation system, a gas sealing system and the like need to be arranged are solved. The whole machine is complicated in structure, the later maintenance cost is high, and the lubricating medium of the lubricating system is easy to pollute the conveyed gas. The magnetic suspension compressor comprises a shell, a motor stator, a motor rotor, a compression rotating shaft, a multi-stage compression impeller and a plurality of magnetic suspension bearings, wherein the shell is provided with a compressed gas passage and a separation cooling passage. An intermediate gear box transmission link, a bearing lubricating system and a cooling system are omitted, and the operation and maintenance cost of the whole machine is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of compressors, and in particular relates to a compressor for quantitatively separating natural gas for self-cooling after primary compression. Background Art

[0002] Traditional gas compressor solutions mostly adopt the motor-gearbox-compressor model, and are also required to be equipped with a bearing lubrication system, cooling and heat dissipation system, and gas sealing system, etc., which leads to a complex structure of the whole machine, high subsequent maintenance costs, and the lubricating medium of the lubrication system is easy to contaminate the transported gas. Summary of the invention

[0003] In view of this, in order to solve the problem that the traditional gas compressor whole machine solution adopts the motor-gearbox-compressor mode, it also needs to be equipped with a bearing lubrication system, a cooling and heat dissipation system, and a gas sealing system. This leads to a complex structure of the whole machine, high maintenance costs in the later stage, and the lubricating medium of the lubrication system easily pollutes the conveying gas. The present invention provides a compressor that quantitatively separates the conveying gas after the first-stage compression for self-cooling, and uses a high-speed motor to directly drive the compression device through a coupling, thereby reducing the intermediate gearbox transmission link and improving the system efficiency; all bearings of the whole machine adopt magnetic bearings, and the maintenance-free characteristics of magnetic bearings are utilized to eliminate the lubrication system, reduce the friction loss of the whole machine, and reduce the heat generated by friction during operation; after compressing part of the conveying gas, it is introduced into the internal cooling channel of the whole machine for cooling the whole machine, eliminating the cooling and heat dissipation system. The operation and maintenance cost of the whole machine is reduced, and the maintenance cycle of the whole machine is extended.

[0004] To achieve the above-mentioned object, the present invention adopts the following technical scheme: a compressor for quantitatively separating the natural gas for self-cooling after primary compression, comprising a housing, a motor stator, a motor rotor, a compression shaft, a multi-stage compression impeller and a plurality of magnetic suspension bearings;

[0005] The motor stator is fixedly connected to the housing, the motor rotor is placed in the motor stator, the motor rotor and the compression shaft are supported and fixed in the housing through a plurality of magnetic bearings, the motor rotor and the compression shaft are connected through a coupling, and the multi-stage compression impeller is inserted and fixed on the compression shaft;

[0006] The housing is provided with a compressed gas passage and a separation cooling passage;

[0007] The compressed gas passage comprises an air inlet, a compression section and an air outlet which are connected in sequence, the air inlet and the air outlet are arranged on the outer surface of the shell, and the compression section is arranged in the shell around the multi-stage gas compression impeller;

[0008] The multi-stage compression impeller includes a first compression impeller and a second compression impeller, and the compression section between the first compression impeller and the second compression impeller is a first-stage compression section;

[0009] The separated cooling passage comprises a compressed gas outlet disposed on the outer surface of the shell and a plurality of cooling passages opened in the shell and located on both sides of the motor rotor and the compression shaft axially, the compressed gas outlet is connected to the air inlet ends of the plurality of cooling passages through an external pipeline, and a flow control valve and a safety valve are disposed between the two;

[0010] The compressed gas outlet is communicated with the first-stage compression section, and the gas outlet ends of the multiple cooling passages are connected to the gas inlet through external pipelines.

[0011] Furthermore, a one-way valve is provided on the external pipeline connecting the air outlet ends and the air inlet of the multiple cooling passages.

[0012] Furthermore, the plurality of cooling passages include a first cooling passage and a second cooling passage;

[0013] The first cooling passage comprises a first cooling air inlet located on the shell, a first bearing cooling cavity located on the left periphery of the compression shaft, and a first cooling air outlet located on the shell, which are connected in sequence;

[0014] The second cooling passage includes a second cooling air inlet located on the shell, a second bearing cooling cavity located outside the coupling, a motor rotor cooling cavity located on the upper and lower sides of the motor rotor, a third bearing cooling cavity located on the right side of the motor rotor and a second cooling air outlet located on the shell, which are connected in sequence.

[0015] Furthermore, a four-point bearing support method is adopted, and the compression shaft and the motor rotor are independently supported. The multiple magnetic bearings include a left shaft bearing and a right shaft bearing arranged at both ends of the compression shaft, and a left motor bearing and a right motor bearing arranged at both ends of the motor rotor.

[0016] Furthermore, the housing includes an outer housing and an inner housing; the motor stator includes a stator core and a stator winding;

[0017] The outer shell comprises a left end cover, a compression device shell, a motor shell and a right end cover which are fixedly connected in sequence;

[0018] The inner shell includes an air intake end face and an air exhaust end face connected to the compression device outer shell, and a motor left inner cover and a motor right inner cover connected to the motor outer shell. The inner shell also includes an air intake baffle, a compression device middle shell and a baffle. The air intake baffle is connected to the air intake end face; the baffle is arranged around the multi-stage compression impeller and is fixedly connected to the compression device middle shell to form a compression section; the compression device middle shell is connected to the compression device outer shell.

[0019] Furthermore, a motor shielding sleeve is provided between the motor stator and the motor rotor, and the motor rotor is also provided with a stator potting glue. The end of the stator winding is potted with the stator potting glue, the motor housing, the left inner cover of the motor and the right inner cover of the motor are welded and fixed, and the motor shielding sleeve and the left inner cover of the motor and the right inner cover of the motor are welded and fixed, so that the stator winding is completely isolated from the cooling natural gas.

[0020] Furthermore, the air intake partition, the compressor middle shell and the partition can be divided into an upper part and a lower part in the horizontal direction, and after being combined, a complete component is formed with an upper and lower split structure.

[0021] Furthermore, the coupling is a floating spline coupling, both ends of which are external splines that match with the internal splines arranged in the motor rotor and the compression shaft.

[0022] Furthermore, the flow control valve is a ball valve.

[0023] Furthermore, the motor rotor is a permanent magnet rotor or a squirrel cage rotor.

[0024] Compared with the prior art, the compressor of the present invention which performs quantitative separation of the transported gas after primary compression for self-cooling has the following beneficial effects:

[0025] 1. The present invention utilizes a high-speed motor to directly drive the compression device through a coupling, thereby reducing the intermediate gearbox transmission link, integrating the entire machine structure, improving system efficiency, and extending the maintenance cycle of the entire machine.

[0026] 2. The present invention adopts magnetic suspension bearings to reduce frictional heat and frictional losses generated by the system, eliminate the need for a lubrication system, and avoid contamination of the transported gas by the lubrication medium.

[0027] 3. The present invention compresses and separates part of the conveying gas for cooling the whole machine, thereby eliminating the need for a cooling and heat dissipation system and reducing the operation and maintenance costs of the whole machine.

[0028] 4. The present invention adopts a floating spline coupling, which has a high operating speed and only transmits torque but not axial force, so that the connection structure between the internal transmission parts of the whole machine is simple and the transmission is reliable.

[0029] 5. The present invention is provided with a flow control valve, which can flexibly control the gas flow of separation cooling according to the operation status of the whole machine, and is also provided with a safety valve to improve the safety of the whole machine.

[0030] 6. The present invention completely isolates the motor stator winding from the cooling natural gas through processes such as potting and welding, thereby avoiding the risk of explosion during the cooling process. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. 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 accompanying drawings:

[0032] Figure 1 It is a schematic diagram of the overall structure of the compressor of the present invention;

[0033] Figure 2 It is a schematic diagram of the main structure of the compressed gas passage and the partially separated cooling passage of the compressor of the present invention;

[0034] Figure 3 A schematic diagram of the first cooling passage and the second cooling passage of the compressor of the present invention;

[0035] Figure 4 It is a schematic diagram of the main structure of the housing and stator winding seal of the compressor of the present invention;

[0036] Figure 5 A schematic diagram of the plurality of magnetic bearings of the compressor of the present invention;

[0037] Figure 6 A connection diagram of the separation cooling passage and the air inlet of the compressor of the present invention;

[0038] Figure 7 A connection circuit diagram for adding a safety valve to the separated cooling passage of the compressor of the present invention;

[0039] Figure 8 This is a connection diagram of the first cooling passage, the second cooling passage and the air inlet of the compressor of the present invention.

[0040] In the figure: 1-housing; 2-motor stator; 3-motor rotor; 4-compression shaft; 5-multi-stage compression impeller; 6-multiple magnetic bearings;

[0041] IN-air inlet; 11-compression section; 11A-first compression section; 12A-compressed gas outlet; L-multiple cooling passages; 51-first compression impeller; 52-second compression impeller; FV-flow control valve; A-safety valve; CV-check valve;

[0042] 2A- stator core; 2B- stator winding;

[0043] 21-first cooling air inlet; 22-first bearing cooling cavity; 23-first cooling air outlet; 24-second cooling air inlet; 25-second bearing cooling cavity; 26-motor rotor cooling cavity; 27-third bearing cooling cavity; 28-second cooling air outlet;

[0044] 31-motor housing; 32-motor left inner cover; 33-motor right inner cover; 34-right end cover;

[0045] 41-compression device housing; 42-left end cover; 43-intake end face; 44-intake baffle; 45-compression device middle shell; 46-baffle; 47-exhaust end face;

[0046] 61 - left bearing of rotating shaft; 62 - right bearing of rotating shaft; 63 - left bearing of motor; 64 - right bearing of motor. DETAILED DESCRIPTION

[0047] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely explain the technical solutions in the embodiments of the present invention. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict, and the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0048] 1. Specific implementation method 1, see Figure 1-8 To explain this embodiment, the compressor for quantitatively separating natural gas for self-cooling after primary compression of the transported natural gas according to the present invention comprises a housing 1, a motor stator 2, a motor rotor 3, a compression shaft 4, a multi-stage compression impeller 5 and a plurality of magnetic suspension bearings 6;

[0049] The motor stator 2 is fixedly connected to the housing 1, the motor rotor 3 is placed in the motor stator 2, the motor rotor 3 and the compression shaft 4 are supported and fixed in the housing 1 by a plurality of magnetic bearings 6, the motor rotor 3 and the compression shaft 4 are connected by a coupling, and the multi-stage compression impeller 5 is inserted and fixed on the compression shaft 4; the present invention directly connects the motor output shaft to the compression device through a coupling, reduces the intermediate gearbox transmission link, and improves the system transmission efficiency. All bearings use magnetic bearings to reduce friction heat generation and friction loss, and utilize the maintenance-free characteristics of magnetic bearings, thereby eliminating the bearing lubrication system and avoiding the lubricating medium from contaminating the conveying gas.

[0050] The housing 1 is provided with a compressed gas passage and a separation cooling passage;

[0051] The compressed gas passage includes an air inlet IN, a compression section 11 and an air outlet which are connected in sequence, wherein the air inlet IN and the air outlet are arranged on the outer surface of the shell 1, and the compression section 11 is arranged in the shell 1 around the multi-stage gas compression impeller 5;

[0052] The multi-stage compression impeller 5 includes a first compression impeller 51 and a second compression impeller 52, and the compression section 11 between the first compression impeller 51 and the second compression impeller 52 is a first-stage compression section 11A;

[0053] The separated cooling passage comprises a compressed gas outlet 12A arranged on the outer surface of the shell 1 and a plurality of cooling passages L opened in the shell 1 and located on both axial sides of the motor rotor 3 and the compression shaft 4. The compressed gas outlet 12A is connected to the air inlet ends of the plurality of cooling passages L through an external pipeline, and a flow control valve FV and a safety valve A are arranged between the two. The present invention takes into account that the temperature rise of the gas after the first stage of compression is not obvious and can be used for cooling, and the temperature of the gas after subsequent multi-stage compression increases step by step and is not suitable for use as a cooling medium. Therefore, a compressed gas outlet 12A is opened in the first stage compression section 11A, and a flow control valve is used to quantitatively separate the compressed gas and enter the cooling channel in the shell to cool the entire machine, thereby eliminating an additional cooling and heat dissipation system.

[0054] The compressed gas outlet 12A is connected to the first compression section 11A, and the outlet ends of the multiple cooling passages L are connected to the air inlet IN through external pipes. After the gas completes the cooling task, it is re-entered into the air inlet IN through the pipe, and the cooling process does not consume the conveying gas.

[0055] A one-way valve is provided on the external pipeline connecting the gas outlet end of the plurality of cooling passages L and the gas inlet IN of the present invention to prevent the gas from flowing back into the cooling passage when the whole machine is started, and ensure that all the conveyed gas enters the compression passage.

[0056] The plurality of cooling passages L of the present invention include a first cooling passage and a second cooling passage;

[0057] The first cooling passage includes a first cooling air inlet 21 located on the shell 1, a first bearing cooling cavity 22 located on the left periphery of the compression shaft 4, and a first cooling air outlet 23 located on the shell 1, which are connected in sequence; after the cooling gas is separated from the compression section 11A, it passes through the compressed gas outlet 12A, the flow control valve FV and the safety valve A, and enters the first bearing cooling cavity 22 from the first cooling air inlet 21. After completing heat exchange with the magnetic suspension bearing, it is discharged from the first cooling air outlet 23 and merges into the air inlet IN.

[0058] The second cooling passage includes a second cooling air inlet 24 on the housing 1, a second bearing cooling cavity 25 located outside the coupling, a motor rotor cooling cavity 26 located on the upper and lower sides of the motor rotor 3, a third bearing cooling cavity 27 located on the right side of the motor rotor 3, and a second cooling air outlet 28 on the housing 1, which are connected in sequence. After the cooling gas is separated from the compression section 11A, it passes through the compressed gas outlet 12A, the flow control valve FV and the safety valve A, enters the second bearing cooling cavity 25 from the second cooling air inlet 24 to complete the heat exchange with the bearing, and then enters the motor rotor cooling cavity 26, completes the heat exchange through the air gap between the motor rotor and the housing, enters the third bearing cooling cavity 27 to complete the heat exchange with the bearing, and then is discharged through the second cooling air outlet 28 and merges into the air inlet IN to complete the cooling of the entire machine.

[0059] The present invention adopts a four-point bearing support method, and the compression shaft 4 and the motor rotor 3 are independently supported. The multiple magnetic bearings 6 include a left shaft bearing 61 and a right shaft bearing 62 arranged at both ends of the compression shaft 4, and a left motor bearing 63 and a right motor bearing 64 arranged at both ends of the motor rotor 3. The four support points are evenly distributed at both ends of the two shafts, which enhances the rigidity of the entire system, reduces the bending deformation caused by external force, ensures the straightness and parallelism of the shaft, and thus improves the overall stability and operation accuracy of the system.

[0060] The housing 1 of the present invention includes an outer housing and an inner housing; the motor stator 2 includes a stator core 2A and a stator winding 2B;

[0061] The outer shell includes a left end cover 42, a compression device housing 41, a motor housing 31 and a right end cover 34 which are fixedly connected in sequence;

[0062] The inner shell includes an air intake end face 43 and an air exhaust end face 47 connected to the compression device outer shell 41, and a motor left inner cover 32 and a motor right inner cover 33 connected to the motor outer shell 31. The inner shell also includes an air intake baffle 44, a compression device middle shell 45 and a baffle 46. The air intake baffle 44 is connected to the air intake end face 43; the baffle 46 is arranged around the multi-stage compression impeller 5 and is fixedly connected to the compression device middle shell 45 to form a compression section 11; the compression device middle shell 45 is connected to the compression device outer shell 41.

[0063] According to the present invention, a motor shielding sleeve 35 is provided between the motor stator 2 and the motor rotor 3, and the motor rotor 3 is also provided with a stator potting glue 36. The stator potting glue 36 is used to pot the end of the stator winding 2B, and the motor housing 31, the motor left inner cover 32 and the motor right inner cover 33 are welded and fixed, and the motor shielding sleeve 35 is welded and fixed to the motor left inner cover 32 and the motor right inner cover 33, so that the stator winding 2B is completely isolated from the cooling natural gas. The end of the motor stator winding is potted to enhance its heat exchange capacity, completely isolate it from the cooling natural gas, and ensure the safe operation of the motor.

[0064] The air intake partition 44, the compressor middle shell 45 and the partition 46 of the present invention can be divided into an upper part and a lower part in the horizontal direction, and after being combined, a complete component upper and lower split structure is formed, which is conducive to the production and installation of the whole machine.

[0065] The coupling of the present invention is a floating spline coupling, both ends of which are external splines, which cooperate with the internal splines provided in the motor rotor 3 and the compression shaft 4. The floating spline coupling has a high operating speed, only transmits torque, does not transmit axial force, has a simple structure, and is highly reliable. The coupling can also be a flexible coupling.

[0066] The flow control valve FV of the present invention is a ball valve, which is quick and easy to operate, has low energy loss in gas flow, low failure rate, is easy to install and maintain, and reduces long-term operating costs.

[0067] According to the compressor for self-cooling after quantitative separation of natural gas after primary compression as claimed in any of the above claims, the motor rotor 3 is a permanent magnet rotor or a squirrel cage rotor. The permanent magnet rotor or squirrel cage rotor has low energy loss, reliable structural design, can withstand long-term continuous operation, ensures long-term stability and reliability, and reduces the operating cost of the whole machine.

[0068] The embodiments of the present invention disclosed above are only used to help illustrate the present invention. The embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. According to the content of this specification, many modifications and changes can be made. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well.

Claims

1. A compressor for quantitatively separating natural gas for self-cooling after primary compression, characterized in that: It comprises a housing (1), a motor stator (2), a motor rotor (3), a compression shaft (4), a multi-stage compression impeller (5) and a plurality of magnetic suspension bearings (6); The motor stator (2) is fixedly connected to the housing (1), the motor rotor (3) is placed in the motor stator (2), the motor rotor (3) and the compression shaft (4) are supported and fixed in the housing (1) by a plurality of magnetic bearings (6), the motor rotor (3) and the compression shaft (4) are connected by a coupling, and the multi-stage compression impeller (5) is inserted and fixed on the compression shaft (4); The housing (1) is provided with a compressed gas passage and a separation cooling passage; The compressed gas passage comprises an air inlet (IN), a compression section (11) and an air outlet which are connected in sequence, the air inlet (IN) and the air outlet being arranged on the outer surface of the shell (1), and the compression section (11) being arranged in the shell (1) around a multi-stage gas compression impeller (5); The multi-stage compression impeller (5) is provided with a first compression impeller (51) and a second compression impeller (52), and the compression section (11) between the first compression impeller (51) and the second compression impeller (52) is a first-stage compression section (11A); The separated cooling passage comprises a compressed gas outlet (12A) arranged on the outer surface of the housing (1) and a plurality of cooling passages (L) opened in the housing (1) and located on both sides of the motor rotor (3) and the compression shaft (4) in the axial direction, the compressed gas outlet (12A) and the air inlet ends of the plurality of cooling passages (L) being connected via an external pipeline, and a flow control valve (FV) and a safety valve (A) being arranged between the two; The compressed gas outlet (12A) is in communication with the first compression section (11A), and the gas outlet ends of the plurality of cooling passages (L) are connected to the gas inlet (IN) through an external pipeline.

2. A compressor for self-cooling after primary compression of natural gas according to claim 1, characterized in that: A one-way valve (CV) is provided on an external pipeline connecting the gas outlet ends of the plurality of cooling passages (L) and the gas inlet (IN).

3. A compressor for self-cooling after primary compression of natural gas according to claim 1, characterized in that: The plurality of cooling passages (L) include a first cooling passage and a second cooling passage; The first cooling passage comprises a first cooling air inlet (21) located on the shell (1), a first bearing cooling cavity (22) located on the left periphery of the compression shaft (4), and a first cooling air outlet (23) located on the shell (1), which are connected in sequence; The second cooling passage comprises a second cooling air inlet (24) located on the housing (1), a second bearing cooling cavity (25) located on the periphery of the coupling, a motor rotor cooling cavity (26) located on the upper and lower sides of the motor rotor (3), a third bearing cooling cavity (27) located on the right side of the motor rotor (3), and a second cooling air outlet (28) located on the housing (1), which are connected in sequence.

4. A compressor for self-cooling after primary compression of natural gas according to claim 3, characterized in that: A four-point bearing support method is adopted, wherein the compression shaft (4) and the motor rotor (3) are independently supported, and the plurality of magnetic suspension bearings (6) include a left shaft bearing (61) and a right shaft bearing (62) arranged at both ends of the compression shaft (4), and a left motor bearing (63) and a right motor bearing (64) arranged at both ends of the motor rotor (3).

5. A compressor for self-cooling after primary compression of natural gas according to claim 4, characterized in that: The housing (1) comprises an outer housing and an inner housing; the motor stator (2) comprises a stator core (2A) and a stator winding (2B); The outer shell comprises a left end cover (42), a compression device shell (41), a motor shell (31) and a right end cover (34) which are fixedly connected in sequence; The inner shell comprises an air intake end face (43) and an air exhaust end face (47) connected to the compression device outer shell (41), and a motor left inner cover (32) and a motor right inner cover (33) connected to the motor outer shell (31); the inner shell further comprises an air intake baffle (44), a compression device middle shell (45) and a baffle (46); the air intake baffle (44) is connected to the air intake end face (43); the baffle (46) is arranged around the multi-stage compression impeller (5) and is fixedly connected to the compression device middle shell (45) to form a compression section (11); the compression device middle shell (45) is connected to the compression device outer shell (41).

6. A compressor for self-cooling after primary compression of natural gas according to claim 5, characterized in that: A motor shielding sleeve (35) is provided between the motor stator (2) and the motor rotor (3), and the motor rotor (3) is also provided with a stator potting glue (36). The stator potting glue (36) is used to pot the end of the stator winding (2B), the motor housing (31), the motor left inner cover (32) and the motor right inner cover (33) are welded and fixed, and the motor shielding sleeve (35) and the motor left inner cover (32) and the motor right inner cover (33) are welded and fixed, so that the stator winding (2B) is completely isolated from the cooling natural gas.

7. A compressor for self-cooling after primary compression of natural gas according to claim 6, characterized in that: The air intake partition (44), the compressor middle shell (45) and the partition (46) are all upper and lower split structures.

8. The compressor for self-cooling after primary compression of natural gas according to claim 1, characterized in that: The coupling is a floating spline coupling, both ends of which are external splines that match the internal splines arranged in the motor rotor (3) and the compression shaft (4).

9. A compressor for self-cooling after primary compression of natural gas according to claim 1, characterized in that: The flow control valve (FV) is a ball valve.

10. A compressor for self-cooling after primary compression of natural gas according to any one of the above claims, characterized in that: The motor rotor (3) is a permanent magnet rotor or a squirrel cage rotor.

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