Compressor, refrigerant circulation system, and air conditioning apparatus

Abstract

The present application relates to a kind of compressor, refrigerant circulation system and air conditioning equipment, compressor includes: shell (5);Rotating shaft (17), is installed in the inner cavity of the shell (5);Gas bearing, is installed in the inner cavity of the shell (5), and is configured to carry the rotating shaft (17);First impeller (2), is installed on the rotating shaft (17), and is located in the inner cavity of the shell (5) outside;First gas supply flow channel (21), with the inner cavity of the shell (5), be configured to the refrigerant output by the first impeller (2) is sent to the gas bearing in the inner cavity of the shell (5), improve the problem that possibly existing liquid refrigerant in refrigerant sent to gas bearing in prior art.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of refrigeration technology, in particular to a compressor, a refrigerant circulation system and an air conditioning device. BACKGROUND

[0002] The centrifugal water chiller is a central air conditioner with large refrigerating capacity, and is usually used in various large buildings. The centrifugal water chiller is composed of an evaporator, a centrifugal compressor, a condenser, a flash tank, a throttling device and the like. The bearing is one of the core parts of the centrifugal compressor, and is used to support the mechanical rotation of the motor shaft. The gas bearing suspends the rotor by using gaseous medium, has a series of advantages such as oil-free, high speed, small vibration and high temperature resistance, and is a new generation of high-precision bearing technology, which is very suitable for the field of turbine machinery.

[0003] In the related art, the refrigerant of the refrigeration system is delivered to the inner cavity of the compressor as the working medium of the gas bearing. When the gas bearing works, high-speed rotation will generate heat, and the motor will also transfer part of the heat to the bearing. If the refrigerant delivered to the gas bearing includes liquid refrigerant, the liquid refrigerant will volatilize easily under heat, which will destroy the dynamic pressure effect of the bearing and affect the generation of the gas film. SUMMARY

[0004] The present application aims to provide a compressor, a refrigerant circulation system and an air conditioning device to improve the problem that liquid refrigerant may exist in the refrigerant delivered to the gas bearing in the prior art.

[0005] According to one aspect of an embodiment of the present application, the present application provides a compressor, which in some embodiments comprises:

[0006] a housing;

[0007] a rotating shaft installed in the inner cavity of the housing;

[0008] a gas bearing installed in the inner cavity of the housing and configured to carry the rotating shaft;

[0009] a first impeller installed on the rotating shaft and located outside the inner cavity of the housing;

[0010] a first gas supply channel in communication with the inner cavity of the housing and configured to deliver the refrigerant output by the first impeller to the gas bearing in the inner cavity of the housing.

[0011] In some embodiments, the compressor further comprises a first gas inlet provided on the housing and used to introduce the refrigerant delivered to the gas bearing,

[0012] the first gas inlet is used to connect the condenser of the refrigerant circulation system; or

[0013] the first gas inlet is connected with the exhaust port of the compressor.

[0014] In some embodiments,

[0015] The first gas supply channel is provided with a first one-way sealing structure configured to prevent the refrigerant in the inner cavity of the shell from flowing to the first impeller through the first gas supply channel; and / or

[0016] The first gas supply channel is configured to be switchable between a cutoff state and a conduction state.

[0017] In some embodiments, the first one-way sealing structure comprises a comb seal structure.

[0018] In some embodiments, the compressor further comprises:

[0019] The first control valve is in communication with the first gas inlet to control the on-off of the condenser and the first gas inlet or the on-off of the exhaust port of the compressor and the first gas inlet; and

[0020] The controller is in signal connection with the first control valve and is configured to close the first control valve during the start and / or stop stage of the compressor.

[0021] In some embodiments, the compressor further comprises:

[0022] The first diffuser channel extends from the end of the first impeller away from the rotating shaft in the radial direction of the rotating shaft;

[0023] The first partition plate is arranged between the inner cavity of the shell and the first diffuser channel;

[0024] One end of the first gas supply channel is in communication with the first diffuser channel, and the other end is in communication with the inner cavity of the shell.

[0025] In some embodiments, the compressor further comprises a first bearing support arranged between the shell and the rotating shaft, the gas bearing comprises a first radial bearing arranged between the first bearing support and the rotating shaft and / or a first thrust bearing located on the side of the first bearing support away from the first gas supply channel, and the compressor further comprises:

[0026] The first flow channel is used to transport the refrigerant introduced by the first gas supply channel to the first radial bearing, and the first flow channel comprises a first hole formed on the first bearing support, the first hole extending towards the first radial bearing; and / or

[0027] The second flow channel is used to transport the refrigerant introduced by the first gas supply channel to the first thrust bearing, and the second flow channel comprises a second hole formed on the first bearing support, the second hole extending from one end to the other end of the first bearing support in the axial direction.

[0028] In some embodiments,

[0029] The first bearing support is provided with a first chamber in communication with the first gas supply channel,

[0030] The first hole extends from the first chamber towards the first radial bearing;

[0031] The second hole extends from the first chamber towards an end of the first bearing support away from the first gas supply channel.

[0032] In some embodiments, the compressor further comprises a thrust bearing fixing plate arranged at a side of the first thrust bearing away from the first bearing support, and a motor cavity accommodating the motor at a side of the thrust bearing fixing plate away from the first thrust bearing, wherein an intermediate flow channel for guiding the flow through the first thrust bearing towards the motor cavity is arranged on the thrust bearing fixing plate or between the thrust bearing fixing plate and the shaft.

[0033] In some embodiments, the compressor further comprises a thrust disc connected to the shaft, the first thrust bearing is arranged between the thrust disc and the first bearing support, and a second thrust bearing is further arranged between the thrust disc and the thrust bearing fixing plate, wherein the second thrust bearing is configured to bear thrust in a direction opposite to the first thrust bearing.

[0034] In some embodiments, the compressor further comprises:

[0035] A second impeller mounted on the shaft and arranged at a side of the housing opposite to the first impeller;

[0036] A second gas supply channel in communication with an outlet of the second impeller and the inner cavity of the housing, for delivering the refrigerant output by the second impeller to the gas bearing in the inner cavity of the housing.

[0037] In some embodiments,

[0038] The second gas supply channel is provided with a second one-way sealing structure configured to prevent the refrigerant in the inner cavity of the housing from flowing to the second impeller through the second gas supply channel; and / or

[0039] The second gas supply channel is configured to be switchable between a cut-off state and a conduction state.

[0040] In some embodiments, the second one-way sealing structure comprises a comb seal structure.

[0041] In some embodiments, the second impeller is configured to compress the refrigerant compressed by the first impeller.

[0042] In some embodiments, the housing is further provided with a refrigerant inlet for delivering cooling refrigerant to the motor in the housing, wherein a distance between the refrigerant inlet and the first impeller is greater than a distance between the refrigerant inlet and the second impeller.

[0043] In some embodiments, the shell is provided with a motor in transmission connection with the rotating shaft, and a cavity of the motor near the first gas supply channel is smaller than a cavity of the motor near the second gas supply channel.

[0044] According to another aspect of the present application, there is also provided a refrigerant circulation system comprising the compressor as described above.

[0045] According to another aspect of the present application, there is also provided an air conditioning device comprising the compressor as described above.

[0046] By applying the technical solution of the present application, since the pressure and temperature of the refrigerant delivered to the gas bearing by the first gas supply channel are both high, the problem of liquid being carried in the refrigerant delivered to the gas bearing is solved. Further, the problem of insufficient pressure of the refrigerant delivered to the gas bearing during the start-up or shutdown phase of the unit in the related art is also solved.

[0047] Other features and advantages of the present application will become apparent from the following detailed description of exemplary embodiments thereof, taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0048] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0049] Figure 1 A structural schematic diagram of an embodiment of the present application is shown;

[0050] Figure 2 A structural schematic diagram of an embodiment of the present application is shown;

[0051] Figure 3 A structural schematic diagram of a control valve of a hydraulic system of an embodiment of the present application is shown; and

[0052] Figure 4 A structural schematic diagram of a buffer valve group of a hydraulic system of an embodiment of the present application is shown. DETAILED DESCRIPTION

[0053] Clearly, the embodiments described are only a part of all the embodiments of the present application, rather than all the embodiments. The following description of at least one example embodiment is merely illustrative in nature and is in no way intended to limit the present application, its application, or uses. Based upon the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of the present application.

[0054] In combination Figures 1 to 3 As shown in the drawings, the compressor of the present embodiment includes a housing 5, a rotating shaft 17, a gas bearing, a first impeller 2, and a first gas supply flow channel 21. The rotating shaft 17 is installed in the inner cavity of the housing 5; the gas bearing is installed in the inner cavity of the housing 5 and is configured to carry the rotating shaft 17; the first impeller 2 is installed on the rotating shaft 17; and the first gas supply flow channel 21 communicates the outlet of the first impeller 2 and the inner cavity of the housing 5 to deliver the refrigerant output by the first impeller 2 to the gas bearing in the inner cavity of the housing 5.

[0055] In the start-up or shutdown phase of the refrigerant circulation system including the compressor of the present embodiment, the first gas supply flow channel 21 can deliver the refrigerant output through the outlet end of the first impeller 2 to the inner cavity of the housing 5, which has high temperature and pressure, to serve as the working medium of the gas bearing. Since the refrigerant delivered by the first gas supply flow channel 21 to the gas bearing has high temperature and pressure, it is beneficial to solve the problem of carrying liquid in the refrigerant delivered to the gas bearing. Further, it is also beneficial to solve the problem of insufficient pressure of the refrigerant delivered to the gas bearing in the start-up or shutdown phase of the unit caused by delivering the refrigerant from the condenser of the refrigerant circulation system to the gas bearing in the related art.

[0056] The first impeller 2 is installed on the first end of the rotating shaft 17 through the first impeller locking nut 1, and the compressor further includes a first volute 3 sleeved outside the first impeller 2 and a first pressure expansion flow channel 22 located between the first volute 3 and the first impeller 2. The refrigerant accelerated by the first impeller 2 flows radially outward and enters the first pressure expansion flow channel 22, and the refrigerant compressed in the first pressure expansion flow channel 22 is collected by the first volute 3 and discharged from the outlet of the first volute 3.

[0057] The housing 5 is provided with a first gas inlet 24 for connecting the condenser of the refrigerant circulation system to introduce the refrigerant delivered to the gas bearing. In the normal operation phase of the refrigerant circulation system, the refrigerant in the condenser is in a high-temperature and high-pressure state, which can serve as the working medium of the gas bearing. In other embodiments, the first gas inlet 24 is connected with the exhaust port of the compressor to introduce the refrigerant compressed by the compressor.

[0058] Further, in the normal operation stage of the unit, the refrigerant from the exhaust port of the condenser or the compressor is used instead of the first gas supply channel 21, which is advantageous to increase the amount of refrigerant entering the first diffuser channel 22 and the next impeller, thereby improving the compression efficiency of the compressor.

[0059] The refrigerant in the refrigerant circulation system is used for heat exchange of the condensation-evaporation circulation system, and the first gas supply channel 21 delivers part of the refrigerant output by the first impeller 2 to the inner cavity of the shell 5 as the working medium of the gas bearing.

[0060] In the normal operation stage of the unit, the refrigerant from the exhaust port of the condenser or the compressor is used instead of the first gas supply channel 21, which is advantageous to increase the amount of refrigerant entering the first diffuser channel 22 and the next impeller, thereby improving the compression efficiency of the compressor.

[0061] In the present embodiment, the first one-way sealing structure 23 is arranged in the first gas supply channel 21, and the first one-way sealing structure 23 is configured to prevent the refrigerant introduced through the first gas inlet 24 from flowing to the first impeller 2 through the first gas supply channel 21. When the pressure on the first side of the first one-way sealing structure 23 is greater than that on the second side, the refrigerant can flow from the first side to the second side of the first one-way sealing structure 23; when the pressure on the second side of the first one-way sealing structure 23 is greater than that on the first side, the first one-way sealing structure prevents the refrigerant from flowing from the second side to the first side of the first one-way sealing structure 23.

[0062] In the normal stage of the refrigerant circulation system, the pressure of the refrigerant output by the exhaust port of the compressor or the refrigerant in the condenser is relatively high, and the pressure of the refrigerant output by the first impeller 2 is relatively low, so the gas output by the first impeller 2 will not be delivered to the gas bearing in the shell 5 through the first gas supply channel 21.

[0063] In some embodiments, the first one-way sealing structure 23 includes a comb seal structure.

[0064] Referring to Figure 4 In the normal operation of the unit, the first gas inlet 24 introduces the refrigerant from the exhaust port of the condenser or the compressor into the inner cavity of the shell 5, i.e., into the second side 37 of the first one-way sealing structure 23.

[0065] Since the gas pressure of the high-pressure refrigerant gas on the second side 37 of the comb structure is greater than the pressure of the refrigerant output by the first impeller 2 introduced by the first gas supply channel 21 on the first side of the comb structure, the comb seal structure prevents the refrigerant output by the first impeller 2 from flowing in the inner cavity of the shell 5, and the comb seal structure can function as a one-way seal.

[0066] The working principle of the comb seal structure is as follows: when the high-pressure refrigerant gas of the second side 37 flows through the gap 43 between the comb seal structure and the flow channel wall of the first gas supply flow channel 21, an approximately ideal throttling process occurs, the pressure and temperature of the refrigerant decrease, the speed increases, and the refrigerant becomes a high-pressure refrigerant gas. When the high-pressure refrigerant continues to flow into the cavity 44 between the adjacent two teeth of the sealing comb, the flow area suddenly becomes larger, the high-pressure refrigerant gas forms a strong vortex, the pressure does not change but the speed almost completely disappears, and a high-pressure refrigerant gas is formed. The high-pressure refrigerant gas 44 continues to flow to the next comb gap 43 and repeats the above process. As the above process proceeds, more and more gas accumulates in the cavity between the adjacent two teeth, and the gas speed in the cavity 44 is almost zero. Therefore, the more the gas accumulates, the higher the pressure in the cavity 44 between the adjacent two teeth, and thus the high-pressure refrigerant gas of the second side 45 of the comb seal structure 23 has a very high pressure, which is greater than the pressure of the refrigerant gas output by the first impeller 2 and the pressure of the second side 37 of the comb seal structure 23. Therefore, the refrigerant output by the first impeller 2 cannot flow to the front bearing cavity, and the high-pressure refrigerant gas of the second side 37 of the comb seal structure 23 no longer flows to the side of the first impeller 2, and the whole achieves a sealing balance.

[0067] In other embodiments, the first gas supply flow channel 21 is configured to be switchable between a cut-off state and a conduction state. Specifically, the end of the first gas supply flow channel 21 away from the first impeller 2 is provided with a valve piece, and the refrigerant pressure output by the first impeller 2 can push the valve piece open to open the first gas supply flow channel 21, and the refrigerant gas introduced by the first gas inlet 24 pushes the valve piece in the direction of closing the first gas supply flow channel 21.

[0068] The compressor further comprises a first control valve and a controller. The first control valve is in communication with the first gas inlet 24 to control the opening and closing of the condenser and the first gas inlet 24 or the opening and closing of the exhaust port of the compressor and the first gas inlet 24. The controller is in signal connection with the first control valve and is configured to close the first control valve during the start and / or stop stage of the compressor. When the refrigerant circulation system is normally running, the first control valve is opened to deliver the refrigerant in the exhaust port of the compressor or the condenser to the gas bearing in the housing 5.

[0069] The compressor further comprises a first expansion flow channel 22 and a first partition plate 4. The first expansion flow channel 22 extends away from the shaft 17 in the radial direction of the shaft 17 from the end of the first impeller 2 away from the shaft 17. The first partition plate 4 is arranged between the inner cavity of the housing 5 and the first expansion flow channel 22. One end of the first gas supply flow channel 21 is in communication with the first expansion flow channel 22, and the other end is in communication with the inner cavity of the housing 5.

[0070] The compressor further comprises a first bearing support 7 arranged between the housing 5 and the rotating shaft 17, and the gas bearing comprises a first radial bearing 6 arranged between the first bearing support 7 and the rotating shaft 17 and / or a first thrust bearing 8 arranged on a side of the first bearing support 7 away from the first gas supply passage 21.

[0071] The compressor further comprises a first passage 20 and a second passage 25. The first passage 20 is used to deliver the refrigerant introduced by the first gas supply passage 21 to the first radial bearing 6, and the first passage 20 comprises a first hole formed on the first bearing support 7, which extends towards the first radial bearing 6. The second passage 25 is used to deliver the refrigerant introduced by the first gas supply passage 21 to the first thrust bearing 8, and the second passage 25 comprises a second hole formed on the first bearing support 7, which extends from one axial end of the first bearing support 7 to the other axial end.

[0072] The first bearing support 7 is provided with a first chamber A in communication with the first gas supply passage 21, and the first hole extends from the first chamber A towards the first radial bearing 6, and the second hole extends from the first chamber A towards the end of the first bearing support 7 away from the first gas supply passage 21. The first chamber A is in communication with the first gas inlet 24.

[0073] The compressor further comprises a thrust bearing fixing plate 10 arranged on a side of the first thrust bearing 8 away from the first bearing support 7 and a motor cavity accommodating the motor 11 on a side of the thrust bearing fixing plate 10 away from the first thrust bearing 8, and the thrust bearing fixing plate 10 or between the thrust bearing fixing plate 10 and the rotating shaft 17 is provided with an intermediate passage 26 for guiding the flow through the first thrust bearing 8 towards the motor cavity.

[0074] The compressor further comprises a refrigerant outlet 33 arranged on the housing 5, and specifically the refrigerant outlet 33 is in communication with the motor cavity. The part of the refrigerant delivered by the first gas supply passage 21 to the inner cavity of the housing 5 flows to the motor cavity through the first chamber A, the second passage 25 and the intermediate passage 26, and then flows to the refrigerant outlet 33 through the motor gap 27 between the rotor and the stator of the motor 11.

[0075] The compressor further comprises a thrust disc 19 connected to the rotating shaft 17, and the first thrust bearing 8 is located between the thrust disc 19 and the first bearing support 7, and a second thrust bearing 9 is further arranged between the thrust disc 19 and the thrust bearing fixing plate 10, and the second thrust bearing 9 is configured to bear thrust in the opposite direction to the first thrust bearing 8.

[0076] The compressor further comprises a second impeller 16 and a second gas supply passage 31. The second impeller 16 is mounted on the rotating shaft 17 and located at the two ends of the housing 5 respectively with the first impeller 2, and the second gas supply passage 31 is in communication with the outlet of the second impeller 16 and the inner cavity of the housing 5 to deliver the refrigerant output by the second impeller 16 to the gas bearing in the inner cavity of the housing 5.

[0077] The second impeller 16 is mounted on the second end of the rotating shaft 17 by a second impeller locking nut 18. The compressor further comprises a second volute 15 sleeved on the second impeller 16 and a second diffuser passage 30 located between the second volute 15 and the second impeller 16. The refrigerant accelerated by the second impeller 16 flows radially outward and enters the second diffuser passage 30. The refrigerant compressed in the second diffuser passage 30 is collected by the second volute 15 and discharged from the outlet of the second volute 15.

[0078] The compressor further comprises a second partition plate 14 arranged between the inner cavity of the shell 5 and the second diffuser passage 30. One end of the second gas supply passage 31 is in communication with the second diffuser passage 30, and the other end is in communication with the inner cavity of the shell 5. Specifically, the second gas supply passage 31 is in communication with the second chamber B.

[0079] The gas bearing further comprises a second radial bearing 12 located on the side of the shell 5 close to the second impeller 17. The compressor further comprises a second bearing support 13 sleeved between the second radial bearing 12 and the shell 5.

[0080] The second bearing support 13 is provided with a second chamber B in communication with the second gas supply passage 31, and the second bearing support 13 is provided with a third flow passage 32 for delivering refrigerant to the second radial bearing 12. One end of the third flow passage 32 is in communication with the second chamber B.

[0081] Specifically, the inner cavity of the shell 5 comprises a first bearing cavity, a motor cavity and a second bearing cavity. The motor 11 is arranged in the motor cavity, the stator of the motor 11 is fixedly connected with the shell 5, and the rotor of the motor 11 is connected with the rotating shaft 17. The first bearing support 7, the first radial bearing 6, the first thrust bearing 8 and the second thrust bearing are arranged in the first bearing cavity, the motor for driving the rotating shaft 17 is arranged in the motor cavity, and the second bearing support 13 and the second radial bearing 12 are arranged in the second bearing cavity. The second bearing cavity and the first bearing are respectively located at two ends of the motor cavity.

[0082] The second gas supply passage 31 is provided with a second one-way sealing structure 29 configured to prevent the refrigerant in the inner cavity of the shell 5 from flowing to the second impeller 16 through the second gas supply passage 31. The second one-way sealing structure 29 comprises a comb seal structure. As described above, the comb seal structure has the characteristic of one-way sealing.

[0083] The shell 5 is provided with a second gas inlet 28 for connecting a condenser of a refrigerant circulation system to introduce refrigerant delivered to the gas bearing. The second gas inlet 28 is in communication with the second bearing cavity. Specifically, the second gas inlet 28 is in communication with the second chamber B.

[0084] The compressor further comprises a second control valve and a controller. The second control valve is in communication with the second gas inlet 28 to control the opening and closing of the condenser and the second gas inlet 28 or the opening and closing of the exhaust port of the compressor and the second gas inlet 28. The controller is in signal connection with the second control valve and is configured to close the second control valve during the start-up and / or stoppage of the compressor. When the refrigerant circulation system is in normal operation, the second control valve is opened to deliver the refrigerant in the exhaust port of the compressor or the condenser to the gas bearing in the housing 5.

[0085] In some embodiments, the second gas supply channel 31 is configured to be switchable between a cut-off state and a conducting state.

[0086] Specifically, an end of the second gas supply channel 31 away from the second impeller 16 is provided with a valve piece. The refrigerant pressure output by the second impeller 16 can push the valve piece to open the second gas supply channel 31, and the refrigerant gas introduced by the second gas inlet 28 can push the valve piece to close the second gas supply channel 31.

[0087] In some embodiments, the second impeller 16 is configured to compress the refrigerant compressed by the first impeller 2.

[0088] The housing 5 is further provided with a refrigerant inlet 34 for delivering cooling refrigerant to the motor in the housing 5. The distance between the refrigerant inlet 34 and the second impeller 16 is greater than the distance between the refrigerant inlet 34 and the second impeller 16, and the refrigerant inlet 34 is closer to the second impeller 16, thereby absorbing more heat on the second impeller side.

[0089] The compressor further comprises a cooling flow channel 35 extending in the circumferential direction of the motor 11. The cooling flow channel 35 is in communication with the refrigerant inlet 34. The cooling flow channel 35 extends helically in the circumferential direction of the motor 11 to the first end of the motor 11 in the axial direction, and the second end of the motor 11 in the axial direction is provided with a refrigerant outlet 33 in communication with the inner cavity of the housing 5.

[0090] The refrigerant introduced by the refrigerant inlet 34 flows through the cooling flow channel 35 to the first end of the motor 11 in the axial direction, then flows through the motor gap between the rotor and the stator of the motor 11 to the second end of the motor 11, and then is discharged through the refrigerant outlet 33. In some embodiments, the refrigerant outlet 33 is connected to the evaporator of the refrigerant circulation system.

[0091] In some embodiments, the housing 5 is provided with the motor 11 in driving connection with the rotating shaft 17. The cavity of the motor 11 near one end of the first gas supply channel 21 is smaller than the cavity of the motor near one end of the second gas supply channel 31, which is conducive to heat dissipation on one side of the second impeller 16.

[0092] As Figure 2As shown, in the start-up and shut-down stage of the refrigerant circulation system, the outlet gas of the first impeller 2 and the second impeller 16 is used to supply gas to the gas bearing.

[0093] In the start-up and shut-down stage of the refrigerant circulation system, since the rotating speed of the motor 11 is relatively low, the pressure difference of the whole system is not established, in order to avoid the liquid refrigerant in the motor cavity from entering the gas bearing, the gas from the impeller inside the compressor is used as the working medium of the bearing at this time.

[0094] For the first impeller 2 side, the refrigerant from the evaporator is changed into medium-temperature and medium-pressure refrigerant gas after working in the first impeller 2, and most of the gas accelerated by the first impeller 2 flows to the second impeller 16 for further compression after being compressed by the first diffuser passage 22. Part of the refrigerant gas accelerated by the first impeller 1 flows to the gas bearing (the first radial bearing 6, the first thrust bearing 8 and the second thrust bearing 9) in the shell 5 through the first gas supply passage 21 to supply gas to the gas bearing.

[0095] The first inlet 24 in communication with the first bearing cavity is connected to the top of the condenser, and a first control valve is arranged in the pipeline between the first inlet 24 and the condenser. In the start-up and shut-down stage of the refrigerant circulation system, the first control valve is in the closed state, the first inlet 24 does not take gas from the condenser, and the compressor mainly uses the gas discharged from the outlets of the first impeller 2 and the second impeller 16 to supply gas to the bearing.

[0096] The refrigerant accelerated by the first impeller 2 introduced by the first gas supply passage 21 is delivered to the inner cavity of the shell 5, part of which flows to the first radial bearing 6 through the first flow passage 20, and the other part is delivered to the first thrust bearing 8 and the second thrust bearing 9 through the second flow passage 25, and then the part of the refrigerant flows to the motor cavity through the intermediate flow passage 26, and then flows to the refrigerant outlet 33 through the motor gap 27 between the rotor and the stator of the motor 11. The refrigerant, while serving as the working medium of the gas bearing, can also cool and cool the gas bearing to take away the heat of the bearing.

[0097] The refrigerant from the first impeller 2 is changed into high-temperature and high-pressure refrigerant gas after working in the second impeller 16, and most of the gas accelerated by the second impeller 16 is expanded by the second diffuser passage 30 and then discharged through the second volute. Part of the refrigerant accelerated by the second impeller 16 is delivered to the second bearing cavity in the shell 5 through the second gas supply passage 31 to serve as the working medium of the second radial bearing 12, and the refrigerant flows to the refrigerant outlet 33 after flowing through the second radial bearing 12 and is discharged from the refrigerant outlet 33.

[0098] In the start-up and shut-down phases of the refrigerant circulation system, the gas supply sources of the first radial bearing 6, the first thrust bearing 8 and the second thrust bearing 9 are the outlet gas of the first impeller 2, which is medium-temperature and medium-pressure gas. Since the gas itself has a certain temperature, the refrigerant flowing to the gas bearing, including liquid refrigerant, can be well prevented. The gas supply source of the second radial bearing 12 is the outlet gas of the second impeller 16, which is high-temperature and high-pressure gas. Similarly, it has a certain temperature itself, so the bearing can be well prevented from being liquid.

[0099] In the running phase of the refrigerant circulation system, as the rotating speed of the motor 11 increases, the power of the first impeller 2 and the second impeller 16 becomes stronger and stronger, and the pressure difference of the unit system is gradually established, which is manifested as the evaporator being in a low-temperature and low-pressure state and the condenser being in a high-temperature and high-pressure state. In order to make more refrigerant enter the refrigerant circulation, the first control valve and the second control valve are opened to introduce the refrigerant of the condenser of the circulation system to the first inlet 24 and the second inlet 28. The first part 36 of the refrigerant 38 introduced by the first inlet 24 flows to the first radial bearing 6 through the first flow channel 20. The second part 39 of the refrigerant 38 introduced by the first inlet 24 is transported to the first thrust bearing 8 and the second thrust bearing 9 through the second flow channel 25, and then the part of the refrigerant flows to the motor cavity through the intermediate flow channel 26, and then flows to the refrigerant outlet 33 through the motor gap 27 between the rotor and the stator of the motor 11. The third part 37 of the refrigerant 38 introduced by the first inlet 24 flows to the first one-way sealing structure 23, which can prevent the refrigerant introduced by the first inlet from flowing to the first impeller 2. Since the pressure on the side of the first one-way sealing structure 23 close to the inner cavity of the shell 5 is higher, the gas output by the first impeller 2 can also be prevented from flowing to the inner cavity of the shell 5.

[0100] The first part 42 of the refrigerant 40 introduced by the second inlet 28 is transported to the second radial bearing 12 through the second cavity B and the third flow channel 32. After the refrigerant flows through the second radial bearing 12, it flows to the refrigerant outlet 33 and is discharged by the refrigerant outlet 33.

[0101] The first part 41 of the refrigerant 40 introduced by the second inlet 28 flows to the second one-way sealing 29, which forms a sealing effect when the pressure in the inner cavity of the shell 5 is larger.

[0102] The compressor of the embodiment can prevent the refrigerant transported to the gas bearing from containing liquid. In the start-up and shut-down phases of the refrigerant circulation system, in the case that the internal pressure of the condenser is not low enough to provide a stable gas source, the compressor designs an impeller gas supply flow channel to draw gaseous refrigerant from the outlet of the impeller as the working medium of the dynamic pressure gas bearing.

[0103] In the normal operation stage of the refrigerant circulation system, due to the work of the impeller, a pressure difference is established, high-pressure gaseous refrigerant is drawn from the condenser, on one hand, to replace the gas supply of the impeller as the new working medium of the dynamic pressure gas bearing, on the other hand, to seal the gas supply channel of the impeller, to avoid excessive loss of gas at the outlet of the impeller, and to affect the heat exchange efficiency.

[0104] Through the above design, gaseous refrigerant is supplied to the dynamic pressure gas bearing in all operation stages of the refrigerant circulation system, to prevent the bearing from carrying liquid.

[0105] The above is only an exemplary embodiment of the present application, and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A compressor for a refrigerant circulating system, characterized by comprising: The compressor comprises: a housing (5); a rotating shaft (17) installed in an inner cavity of the housing (5); a gas bearing installed in the inner cavity of the housing (5) and configured to support the rotating shaft (17); a first impeller (2) installed on the rotating shaft (17) and located outside the inner cavity of the housing (5); a first gas supply channel (21) in communication with the inner cavity of the housing (5) and configured to deliver refrigerant output by the first impeller (2) to the gas bearing in the inner cavity of the housing (5), the compressor further comprises a first gas inlet (24) provided on the housing (5) and used to introduce the refrigerant delivered to the gas bearing, the first gas inlet (24) being used to connect a condenser of a refrigerant circulation system; or the first gas inlet (24) being connected with a gas outlet of the compressor, a first one-way sealing structure (23) is provided in the first gas supply channel (21), the first one-way sealing structure (23) being configured to prevent refrigerant in the inner cavity of the housing (5) from flowing to the first impeller (2) through the first gas supply channel (21); and / or the first gas supply channel (21) being configured to be switchable between a cutoff state and a conduction state, the compressor further comprises: a first control valve in communication with the first gas inlet (24) to control the on-off of the condenser and the first gas inlet (24) or the on-off of the gas outlet of the compressor and the first gas inlet (24); and a controller in signal connection with the first control valve and configured to close the first control valve during a starting and / or stopping stage of the compressor and open the first control valve during a normal operation of the refrigerant circulation system to deliver refrigerant in the gas outlet of the compressor or the condenser to the gas bearing in the inner cavity of the housing (5), during a starting or stopping stage of the refrigerant circulation system containing the compressor, the first gas supply channel (21) can deliver refrigerant output through an outlet end of the first impeller (2) to the inner cavity of the housing (5) as a working medium of the gas bearing, the refrigerant having high temperature and pressure; during a normal operation stage of the refrigerant circulation system, refrigerant in the condenser is in a high-temperature and high-pressure state, which can be used as a working medium of the gas bearing, or the first gas inlet (24) is connected with the gas outlet of the compressor to introduce the refrigerant compressed by the compressor.

2. The compressor of claim 1, wherein The first one-way sealing structure (23) comprises a comb-shaped sealing structure.

3. The compressor of claim 1, wherein, Further comprising: a first pressure expansion channel (22) extending away from the rotating shaft (17) in a radial direction of the rotating shaft (17) from an end of the first impeller (2) away from the rotating shaft (17); a first partition plate (4) provided between the inner cavity of the housing (5) and the first pressure expansion channel (22); one end of the first gas supply channel (21) is in communication with the first pressure expansion channel (22), and the other end is in communication with the inner cavity of the housing (5).

4. The compressor of claim 1, wherein The compressor further comprises a first bearing support (7) sleeved between the shell (5) and the rotating shaft (17), the gas bearing comprises a first radial bearing (6) sleeved between the first bearing support (7) and the rotating shaft (17) and / or a first thrust bearing (8) located on a side of the first bearing support (7) away from the first gas supply channel (21), and the compressor further comprises; a first flow channel (20) for conveying the refrigerant introduced by the first gas supply channel (21) to the first radial bearing (6), the first flow channel (20) comprising a first hole formed on the first bearing support (7), the first hole extending towards the first radial bearing (6); and / or a second flow channel (25) for conveying the refrigerant introduced by the first gas supply channel (21) to the first thrust bearing (8), the second flow channel (25) comprising a second hole formed on the first bearing support (7), the second hole extending from one end to the other end of the first bearing support (7) in the axial direction.

5. The compressor of claim 4, wherein, The first bearing support (7) is provided with a first chamber (A) in communication with the first gas supply channel (21), and the first hole extends from the first chamber (A) towards the first radial bearing (6); The second hole extends from the first chamber (A) towards one end of the first bearing support (7) away from the first gas supply channel (21).

6. The compressor of claim 4, wherein, The compressor further comprises a thrust bearing fixing plate (10) provided on a side of the first thrust bearing (8) away from the first bearing support (7) and a motor cavity accommodating a motor (11) on a side of the thrust bearing fixing plate (10) away from the first thrust bearing (8), and an intermediate flow channel (26) is provided on the thrust bearing fixing plate (10) or between the thrust bearing fixing plate (10) and the rotating shaft (17) for guiding the flow through the first thrust bearing (8) towards the motor cavity.

7. The compressor of claim 6, wherein, The compressor further comprises a thrust disc (19) connected to the rotating shaft (17), the first thrust bearing (8) is located between the thrust disc (19) and the first bearing support (7), and a second thrust bearing (9) is further provided between the thrust disc (19) and the thrust bearing fixing plate (10), the second thrust bearing (9) and the first thrust bearing (8) are configured to bear thrust forces in opposite directions.

8. The compressor of claim 1, wherein, The compressor further comprises: a second impeller (16) mounted on the rotating shaft (17) and located at two ends of the shell (5) respectively from the first impeller (2); a second gas supply channel (31) connecting an outlet of the second impeller (16) and an inner cavity of the shell (5) to convey the refrigerant output by the second impeller (16) to the gas bearing in the inner cavity of the shell (5).

9. The compressor of claim 8, wherein, The second gas supply channel (31) is provided with a second one-way sealing structure (29) configured to prevent the refrigerant in the inner cavity of the shell (5) from flowing to the second impeller (16) through the second gas supply channel (31); and / or the second gas supply channel (31) is configured to be switchable between a cut-off state and a conduction state.

10. The compressor of claim 9, wherein, The second one-way sealing structure (29) comprises a comb seal structure.

11. The compressor of claim 8, wherein, The second impeller (16) is configured to compress the refrigerant compressed by the first impeller (2).

12. The compressor of claim 8, wherein, The shell (5) is further provided with a refrigerant inlet (34) for delivering cooling refrigerant to the motor in the shell (5), and the distance between the refrigerant inlet (34) and the first impeller (2) is greater than the distance between the refrigerant inlet (34) and the second impeller (16).

13. The compressor of claim 8, wherein, The shell (5) is provided with a motor in driving connection with the rotating shaft (17), and the cavity of the motor near one end of the first gas supply channel (21) is smaller than the cavity of the motor near one end of the second gas supply channel (31).

14. The compressor of claim 3, wherein, One end of the first gas supply channel (21) is in communication with one end of the first pressure expansion channel (22) near the first impeller (2), and the other end is in communication with the inner cavity of the shell (5).

15. A refrigerant cycle system characterized by comprising: The compressor comprises the compressor according to any one of claims 1 to 14.

16. An air conditioning apparatus characterized by comprising: The compressor comprises the compressor according to any one of claims 1 to 14.

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