Compressor and method of operating compressor

Abstract

A compressor includes a drive shaft, a bearingless motor, one or more magnetic bearings, and a controller for the bearingless motor. The bearingless motor is configured to rotate the drive shaft to compress the working fluid. The one or more magnetic bearings magnetically support the drive shaft as the drive shaft rotates. The controller is configured to adjust magnetic support provided to the drive shaft by the bearingless motor based on operation of the compressor. A method of operating a compressor includes rotating a drive shaft with a bearingless motor to compress a working fluid, and magnetically supporting the drive shaft with one or more magnetic bearings. The method further includes magnetically supporting the drive shaft with a bearingless motor, wherein the magnetic support provided by the bearingless motor is adjusted based on operation of the compressor.

Description

Technical Field

[0001] The present disclosure relates to magnetically supporting a drive shaft in a compressor of an HVACR system. More particularly, the present disclosure relates to magnetically supporting a drive shaft in a compressor for a heating, ventilation, air conditioning, and refrigeration (HVACR) system. Background Art

[0002] HVACR systems are typically used to heat, cool, and / or ventilate enclosed spaces (e.g., the interior of a commercial or residential building, the interior of a refrigerated transport unit, etc.). An HVACR system may include a refrigerant circuit that uses a working fluid to provide cooled or heated air to an area. The refrigerant circuit includes a compressor. The compressor includes a drive shaft that rotates to compress the working fluid and one or more bearings for supporting the rotating drive shaft within the compressor. The one or more bearings may include a magnetic bearing for providing magnetic support to the rotating drive shaft. Summary of the invention

[0003] The HVACR system may include a refrigerant circuit configured to heat or cool a process fluid (eg, air, water, and / or glycol, etc.) The refrigerant includes a compressor that compresses a working fluid that circulates through the refrigerant circuit.

[0004] In one embodiment, a compressor includes a drive shaft, a bearingless motor, one or more magnetic bearings, and a controller. The bearingless motor is configured to rotate the drive shaft to compress a working fluid, and the one or more magnetic bearings are configured to magnetically support the drive shaft when the drive shaft rotates. The controller is configured to adjust the magnetic support provided to the drive shaft by the bearingless motor when the drive shaft rotates based on the operation of the compressor.

[0005] In one embodiment, a method for operating a compressor includes a drive shaft, one or more magnetic bearings, and a bearingless motor. The method includes rotating the drive shaft using the bearingless motor to compress a working fluid, and magnetically supporting the rotating drive shaft using the one or more magnetic bearings. The method also includes magnetically supporting the drive shaft using the bearingless motor. Magnetically supporting the drive shaft using the bearingless motor includes adjusting the magnetic support provided to the drive shaft by the bearingless motor based on the operation of the compressor. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 is a schematic diagram of an embodiment of a refrigerant circuit in an HVACR system.

[0007] Figure 2is a schematic diagram of an embodiment of a compressor.

[0008] Figure 3 is a block flow diagram of an embodiment of a method of operating a compressor.

[0009] Like numbers refer to like features. DETAILED DESCRIPTION

[0010] Heating, ventilation, air conditioning, and refrigeration (HVACR) systems are generally configured to heat and / or cool an enclosed space (e.g., the interior of a commercial or residential building, the interior of a refrigerated transport unit, etc.). The HVACR system includes a heat transfer loop that includes a compressor and a working fluid (e.g., a refrigerant, a refrigerant mixture, etc.) that circulates through the heat transfer loop. The working fluid is used to heat or cool a process fluid (e.g., air, water, and / or glycol, etc.).

[0011] The compressor includes a drive shaft, an electric motor that rotates the drive shaft (e.g., relative to a housing of the compressor) to compress a working fluid, and one or more magnetic bearings that support the rotating drive shaft. The load applied to the drive shaft may vary during operation of the compressor. For example, operating the compressor under certain conditions may cause the load on the drive shaft to increase significantly.

[0012] Abnormal airflow through the compressor will cause a significant increase in the load on the drive shaft. Abnormal airflow may occur when the compressor experiences stall, surge, impact load, asymptomatic pressure, etc. For example, when the airflow through the compressor has a localized area of ​​reduced speed and reverse pressure gradient, stall will occur. When encountering the compression components of the compressor (e.g., impeller, screw, etc.), the localized area will cause airflow separation and / or airflow alignment. For example, when the airflow through the compressor is at least temporarily stopped and / or reversed, surge will occur. Asymptomatic pressure is generated when the circumferential pressure distribution becomes asymmetric, which leads to additional radial loads on the drive shaft. Surge, stall and asymptomatic pressure may occur under various operating conditions of the compressor, but are more likely to occur when the compressor is closer to the upper and lower boundaries of its volume flow rate in its operating map. Surge and stall may occur due to, for example, operating the compressor at a high pressure ratio, unloading the capacity of the compressor at a high pressure ratio, unstable cooler water temperature control, frequent opening / closing of the compressor / refrigerant circuit stage, etc. For example, when the fluid entering the compressor contains an excess of liquid, impact loads occur. For example, the occurrence of liquid suction residue in the refrigerant circuit will cause shock loads. The higher density fluid affects the compression components of the compressor (e.g., impellers, screws, etc.) and may push the compression components radially and / or axially. Stalling, surge, asymptomatic pressure and / or shock loads may cause an increase in axial loads and / or radial loads on the rotating shaft. Imbalance in the drive shaft assembly may also cause the drive shaft to have an increased load on the bearings. Misalignment caused by assembly tolerances, manufacturing tolerances, etc. between the stator axis and the rotor axis of the electric motor may also cause an increase in the load on the drive shaft on the bearings. The increased load on the drive shaft is applied to one or more bearings (e.g., an increased load on the drive shaft on one or more bearings that support the drive shaft when the drive shaft rotates). Without increasing the size of one or more magnetic bearings, this increased load may cause problems with one or more magnetic bearings.

[0013] Embodiments disclosed herein relate to compressors, HVACR systems including compressors, and refrigerant circuits including compressors that utilize a bearingless motor in combination with one or more magnetic bearings configured to provide magnetic support of a drive shaft. The bearingless motor is configured to have magnetic support that is adjusted based on the operation of the compressor so that sufficient support is effectively provided to the drive shaft for increased loads on the drive shaft. For example, a bearingless motor in combination with one or more magnetic bearings can advantageously allow the compressor to operate in / near stall and / or surge conditions without using larger magnetic bearings (e.g., to compensate for increased loads caused by stall and surge).

[0014] Figure 1is a schematic diagram of an embodiment of a refrigerant circuit 5 in an HVACR system 1. In one embodiment, the heat transfer circuit 5 is used in an HVACR system. The refrigerant circuit 5 includes a compressor 10, a condenser 20, an expansion device 30, and an evaporator 40. In one embodiment, the refrigerant circuit 5 can be modified to include additional components, such as an economizer heat exchanger, one or more valves, one or more sensors (e.g., a fluid sensor, a temperature sensor, etc.), a liquid storage tank, etc.

[0015] The various components of the refrigerant circuit 5 are fluidly connected. The refrigerant circuit 5 can be configured as a cooling system that can operate in a cooling mode (e.g., a fluid cooler of an HVACR system, an air conditioning system, etc.), or the refrigerant circuit 5 can be configured as a heat pump system that can operate in a cooling mode or a heating mode.

[0016] The working fluid flows through the refrigerant circuit 5. The working fluid in the refrigerant circuit 5 flows through the compressor 10, the condenser 20, the expansion device 30, the evaporator 40 and returns to the compressor 10. The working fluid may include one or more refrigerants.

[0017] A low-pressure gaseous or mostly gaseous working fluid is drawn into the suction port 12 of the compressor 10. The working fluid is compressed as it flows from the suction port 12 of the compressor 10 to the discharge port 14 of the compressor 10. From the discharge port 14 of the compressor 10, the working fluid flows through the main fluid path 5 to the condenser 20.

[0018] First process fluid PF 1 The first process fluid PF flows through the condenser 20 separately from the working fluid. The condenser 20 is a heat exchanger that allows the working fluid and the first process fluid PF to 1 As they each flow through the condenser 20, they are in heat transfer relationship without physical mixing. As the working fluid flows through the condenser 20, the working fluid is mixed with the first process fluid PF 1 Therefore, the first process fluid PF 1 The first process fluid PF is heated by the working fluid and leaves the condenser 20 at a higher temperature than the temperature at which it enters the condenser 20. In one embodiment, the first process fluid PF 1 It can be air, water and / or glycol, etc., which are suitable for absorbing and transferring heat from the working fluid and the refrigerant circuit 5. For example, the first process fluid PF 1 It may be ambient air circulated from the outside atmosphere, water heated to hot water, or any suitable fluid for transferring heat from the refrigerant circuit 5. The working fluid is cooled by the condenser 20 and becomes liquid or mostly liquid as it cools in the condenser 20.

[0019] The liquid / gas working fluid flows from the condenser 20 to the expansion device 30. The expansion device 30 expands the working fluid. The expansion causes the temperature of the working fluid to be significantly reduced. As described herein, an "expansion device" may also be referred to as an expander. In one embodiment, the expander may be an expansion valve, an expansion plate, an expansion container, an orifice, or the like, or other similar expansion mechanisms. It should be understood that the expander may be any type of expander known in the art for expanding the working fluid to reduce the temperature of the working fluid. The gaseous / liquid working fluid has a lower temperature after being expanded by the expansion device 30.

[0020] The lower temperature gaseous / liquid working fluid then flows from the expansion device 30 to and through the evaporator 40. The second process fluid PF 2 The evaporator 40 is a device that allows the working fluid and the second process fluid PF to flow through the evaporator 40 separately from the working fluid. 2 The heat exchanger is in heat transfer relationship without physical mixing within the evaporator 40. With the working fluid and the second process fluid PF 2 Flowing through the evaporator 40, the working fluid is converted from the second process fluid PF 2 absorbs heat, which cools the second process fluid PF 2 Therefore, the second process fluid PF 2 The working fluid leaves the evaporator 40 at a lower temperature than the temperature at which it enters the evaporator 40. The working fluid is gaseous or mostly gaseous when it leaves the evaporator 40. From the evaporator 40, the working fluid flows to the suction port 12 of the compressor 10.

[0021] In one embodiment, the second process fluid PF 2 The second process fluid PF is the air cooled by the HVACR system and ventilated to the enclosed space to be conditioned. 2 is an intermediate fluid (eg, water, heat transfer fluid, etc.), and the cooled second process fluid PF 2 May be utilized by an HVACR system to cool the air in or ventilate the enclosed space to be conditioned.

[0022] For clarity, in Figure 1 Dashed lines are provided in the figures to indicate fluid flowing through certain components (eg, condenser 20, evaporator 40), and it should be understood that a specific path in each component is not specified. Dot-dash lines are provided in the figures to indicate some features that may be different in other embodiments. Figure 110. The dashed lines are provided in order to illustrate electronic communication between different features. For example, the dashed lines extend from the controller 90 to the motor 16 of the compressor 10. For example, when the controller 90 controls the operation of one or more magnetic bearings 18 of the compressor 10, the dashed lines extend from the controller 90 to the magnetic bearings 18 of the compressor 10. For example, when the controller 90 controls the compressor 10, the dashed lines extend from the controller 90 to the expander 30. In one embodiment, the controller 90 includes a memory (not shown) for storing information and a processor (not shown). Figure 1 The controller 90 described in and below is described / illustrated as a single component. However, it should be understood that Figure 1 The "controller" shown and described herein may include a plurality of discrete or interconnected components, and in one embodiment includes a memory (not shown) and a processor (not shown). For example, the controller 90 may include an HVACR controller component configured to control the overall operation of the HVACR system 1 and a compressor controller component configured to control the operation of the compressor. For example, the HVACR controller component may be configured to determine a cooling demand for the refrigerant circuit 5 (e.g., based on a desired temperature and an actual temperature of the enclosed space conditioned by the HVACR system 1), and the compressor controller may be configured to select a speed and discharge pressure of the compressor 10 that corresponds to the cooling demand.

[0023] Figure 2 is a schematic diagram of a compressor 100. In one embodiment, the compressor 100 may be Figure 1 The compressor 100 includes a compressor housing 105, a drive shaft 120, a bearingless motor 130, and one or more magnetic bearings 150A, 150B. The compressor 100 includes an inlet 107 and an outlet 109. For example, the inlet 107 and the outlet 109 are formed in the compressor housing 105. A working fluid to be compressed flows into the compressor 100 through the inlet 107, and the compressed working fluid is discharged from the compressor through the outlet 109.

[0024] The bearingless motor 130 is configured to rotate the drive shaft 120. For example, the drive shaft 120 rotates relative to the compressor housing 105. The compressor 100 includes an impeller 110 fixed to the drive shaft 120, so that the rotation of the drive shaft 120 also rotates the impeller 110. For example, the drive shaft 120 and the impeller 110 rotate relative to the compressor housing 105. When the drive shaft 120 rotates, the rotating impeller 110 is driven by a relatively low pressure (e.g., at a suction pressure P of the uncompressed gas through the inlet 107). S ) draws the gaseous working fluid f into the compressor 100 and compresses the gaseous working fluid in the compressor 100. Then, the compressed gaseous working fluid is discharged at a relatively high pressure (for example, at the discharge pressure P of the compressed gas discharged from the outlet 109).D ) is discharged from the compressor 100. The drive shaft 120 rotates to compress the (gaseous) working fluid in the compressor 100.

[0025] Figure 2 The compressor 100 in FIG. 1 is a centrifugal compressor having two impellers 110. The impellers 110 are Figure 2 10. However, it should be understood that in one embodiment, the compressor 100 may be a compressor of a different type having a different type and / or a different number of compression mechanisms. In one embodiment, the compressor 100 may be a scroll compressor, which includes one or more scroll members (not shown) fixed to the drive shaft 120 instead of the impeller 110. In one embodiment, the compressor 100 may be a screw compressor, which includes a screw (not shown) fixed to the drive shaft 120 instead of the impeller 110. In one embodiment, the compressor 100 may include one or more compression mechanisms (e.g., a single impeller 110, more than two impellers 110, a single scroll member, two scroll members, etc.) attached to the drive shaft 120.

[0026] The compressor 100 includes a controller 190. The controller 190 may include a magnetic bearing controller 190B for controlling the operation of the one or more magnetic bearings 150A and a motor controller 190A for controlling the operation of the bearingless motor 130. The magnetic bearing controller 190B and the motor controller 190A may be, for example, Figure 2 Discrete modules shown. It should be understood that in another embodiment, the controllers 190A, 190B can be combined into a single module. The controller (e.g., controller 190, motor controller 190A, magnetic bearing controller 190B) can include a memory (not shown) and a processor (not shown) that operates according to instructions stored in the memory.

[0027] like Figure 2 As shown, the compressor 100 may include one or more suction throttle valves 115A, 115B. In the illustrated embodiment, the first suction throttle valve 115A is configured to control the flow rate of the working fluid entering the first impeller 110, and the second suction throttle valve 115B is configured to control the flow rate of the working fluid entering the second impeller 110 (for example, disposed in the fluid path between the first impeller 110 and the second impeller 110, controlling the working fluid flowing from the first impeller 110 to the second impeller 110). For example, the first suction throttle valve 115A may be an inlet guide vane. For example, the second suction throttle valve 115B may be an interstage throttle valve (for example, an interstage throttle valve ring, etc.). The suction throttle valves 115A, 115B may be controlled by the controller 190 of the compressor 100 (for example, controlled by the motor controller 190A).

[0028] The bearingless motor 130 includes a rotor 132 and a stator 134. The rotor 132 and the drive shaft 120 are fixed together so that they rotate together. For example, the rotor 132 and the drive shaft 120 can be fixed together using an interference fit or other types of fits. A bearingless motor is an electric motor that can apply a rotational force (e.g., torque) and a suspension force to the drive shaft. The stator 134 generates an adjustable magnetic field to apply a rotational magnetic force and a suspension magnetic force to the rotor 132. As the rotor 132 is fixed to the drive shaft 120, a rotational (magnetic) force and a suspension (magnetic) force are then applied to the drive shaft 120. The suspension (magnetic) force provides magnetic support for the drive shaft 120. The suspension force and the suspension magnetic force may alternatively be referred to as the levitation force (or levitation magnetic force) of the drive shaft 120.

[0029] The stator 134 may include windings 136. For example, following the principles of a bearingless electric motor, the current passing through the windings 136 is adjusted to adjust the magnetic force applied to the drive shaft 120. The compressor includes a motor controller 190A for controlling the operation of the bearingless motor 130. The motor controller 190A can adjust the current (e.g., increase the amount of current, decrease the amount of current) by flowing through one or more windings 136 to adjust the rotational magnetic force and the suspension magnetic force applied to the drive shaft 120. The suspension magnetic force and the rotational magnetic force can be adjusted separately (e.g., the suspension magnetic force applied to the drive shaft 120 is adjusted when there is a constant rotational magnetic force or an approximately constant rotational magnetic force). The control of the bearingless motor 130 will be discussed in more detail below.

[0030] The magnetic bearings 150A, 150B are configured to magnetically support the rotating drive shaft 120. The magnetic bearings 150A, 150B operate according to known principles of magnetic bearings. For example, one or more magnetic bearings 150A, 150B apply a magnetic force to the drive shaft 120 to support / levitate the drive shaft 120 as the drive shaft 120 rotates. Figure 2 As shown, the magnetic bearings 150A, 150B are each spaced apart from the bearingless motor 130 (e.g., spaced apart along the length of the drive shaft 120). The compressor 100 may include a magnetic bearing controller 190B configured to operate the magnetic bearings 150A, 150B. For example, the controller 190B may be configured to adjust the magnetism applied to the drive shaft 120 by the magnetic bearings 150A, 150B to maintain the drive shaft 120 in a relatively constant position (e.g., relative to the compressor housing 105). In one embodiment, the motor controller may be configured to communicate with the magnetic bearing controller to operate the magnetic support of the bearingless motor 130 (e.g., to cause the magnetic bearings and the bearingless motor to magnetically support the drive shaft in a coordinated manner).

[0031] The magnetic bearings 150A, 150B include at least one radial magnetic bearing. The radial magnetic bearing may be part of a combined radial and thrust magnetic bearing. In the illustrated embodiment, the compressor 100 includes two magnetic bearings 150A, 150B, each of which is a combined radial and thrust magnetic bearing. The magnetic bearings 150A, 150B provide radial support for the drive shaft 120 (e.g., for the magnetic bearing 150B, the radial magnetic bearing 150B is provided by the magnetic bearing 150A, 150B). Figure 2 The magnetic bearings 150A and 150B can also provide axial support for the drive shaft 120 (for example, for the magnetic bearing 150B, the Figure 2 denoted by the dashed arrow in FIG.

[0032] The controller 190 (eg, motor controller 190A) is configured to adjust the magnetic support provided by the bearingless motor 130 based on the operation of the compressor 100 . Figure 2 Dotted lines are provided in the figure to illustrate electronic communication between different features. For example, when the controller 190 receives measurements from the sensor 192A, the dotted line extends from the sensor 192A to the controller 190 (eg, the magnetic bearing controller 190B). Figure 2 The long-short dashed line is provided in the figure to illustrate power. For example, when the controller 190 provides power to the magnetic bearing 150A to control the operation of the magnetic bearing 150A (e.g., the direction of the magnetic force applied to the drive shaft 120 by the magnetic bearing 150A), the long-short dashed line extends from the controller 190 (e.g., the magnetic bearing controller 190B) to the magnetic bearing 150A. Adjustment of the magnetic support provided by the bearingless motor 130 can refer to adjustment of the degree of magnetic support provided to the drive shaft 120 (e.g., the maximum amount of magnetic support, the maximum amount of magnetic levitation force).

[0033] In one embodiment, the bearingless motor 130 can be configured to selectively provide magnetic support to the rotating drive shaft 120. For example, the magnetic support of the bearingless motor 130 is activated only when there is an increased load on the drive shaft (e.g., the increased load supported by the magnetic bearings 150A, 150B). This can advantageously allow the compressor 100 to effectively provide increased support to the drive shaft 120 (e.g., the magnetic support of the bearingless motor 130 is only effective for a portion of the normal operation of the compressor 100). For example, the bearingless motor 130 can be used instead of using an increased magnetic bearing size to address the increased load caused by abnormal airflow through the compressor, so that the compressor 100 has reduced power consumption (e.g., relative to a compressor with a larger size magnetic bearing). In one embodiment, the size of the magnetic bearings 150A, 150B can be designed to provide sufficient support during steady-state operation of the compressor 100, and when the compressor operation causes the drive shaft 120 to have a significantly increased load, the magnetic support of the bearingless motor 130 is used to provide increased support to fully support the drive shaft 120.

[0034] In one embodiment, the magnetic support provided by the bearingless motor 130 is adjusted based on one or more operating conditions of the compressor. The compressor 100 may include one or more sensors 192A, 192B, 194A, 194B, 196 for detecting one or more operating conditions of the compressor 100. For example, the magnetic support provided by the bearingless motor 130 is adjusted by the operating conditions detected by one or more of the sensors 192A, 192B, 194A, 194B. The operating conditions may include, but are not limited to, the position of the drive shaft 120, the suction pressure P of the compressor 100, and the suction pressure P of the compressor 100. S , compressor discharge pressure P D , the rotational speed of the compressor 100 (for example, the rotational speed of the motor 130 ), etc.

[0035] The compressor 100 may include one or more drive shaft position sensors 192A, 192B for detecting the position of the drive shaft 120 (e.g., the relative position of the drive shaft 120). For example, the drive shaft position sensors 192A, 192B are configured to detect the relative axial position and / or relative radial position of the drive shaft 120 (e.g., relative to the drive shaft position sensor, relative to the desired operating position of the drive shaft 120, etc.). The drive shaft position sensor 192A may be used by the magnetic bearings 150A, 150B to adjust the magnetic force applied to the drive shaft 120 by the magnetic bearings 150A, 150B. For example, when the drive shaft 120 moves in a first radial direction (e.g., in the radial direction D1), the magnetic bearings 150A, 150B increase the magnetic force applied to the drive shaft 120 in the opposite direction to push / move the drive shaft 120 back to the desired operating position.

[0036] The drive shaft position sensor 192B may be used to control the magnetic support of the bearingless motor 130. For example, the motor controller 190A may be configured to use the drive shaft position sensor 192B to detect the (current) position of the drive shaft 120 to adjust the magnetic support (e.g., the levitation magnet force) of the bearingless motor 130 based on the detected position of the drive shaft 120. In another embodiment, the motor controller 190A may be configured to use the same drive shaft position sensor 192A as the magnetic bearings 150A, 150B.

[0037] Drive shaft position sensors 192A, 192B are Figure 2 192A, 192B. However, it should be understood that in one embodiment, each drive shaft sensor 192A, 192B may include multiple sensing elements (e.g., gap sensor elements). For example, the sensing elements may be spaced along the circumference of the drive shaft 120 at 90° increments, 60° increments, 30° increments, etc. In one embodiment, each sensing element may be configured to sense the current distance (e.g., radial gap) between the drive shaft 120 and each sensing element, and determine the position of the drive shaft 120 based on the distance sensed by the sensing element.

[0038] The compressor 100 may include one or more pressure sensors 194A, 194B. Figure 2 As shown, the compressor 100 may include an inlet pressure sensor 194A and an outlet pressure sensor 194B. The inlet pressure sensor 194A is configured to detect the suction pressure P of the working fluid entering the compressor 100. S (For example, from Figure 1 The outlet pressure sensor 194B is configured to detect the discharge pressure P of the (compressed) working fluid discharged from the compressor 100. D (For example, from Figure 1 The compressor 10 in the compressor discharges to the condenser 20). The pressure sensors 194A and 194B are located at Figure 2 It should be understood that in other embodiments, one or more pressure sensors 194A, 194B may also be disposed outside the compressor 100 (e.g., in the refrigerant circuit downstream of the evaporator and upstream of the compressor, in the refrigerant circuit between downstream of the compressor and upstream of the evaporator, etc.).

[0039] The magnetic support provided by the bearingless motor 130 to the drive shaft 120 may be adjusted based on an operational map of the compressor 100. For example, the bearingless motor 130 may be configured to provide increased levitation magnetic force to the drive shaft 120 (e.g., activated and / or increased by a smaller amount) when the compressor 100 is operating in one or more specific regions of the operational map (e.g., one or more regions that induce increased radial loads on the drive shaft 120, one or more regions that induce increased axial loads on the drive shaft 120). In such an embodiment, the magnetic support provided by the bearingless motor 130 to the drive shaft 120 may be adjusted based on the suction pressure P S , discharge pressure P D and the rotation speed of the compressor 100 to adjust the suspension magnetic force provided by the bearingless motor 130. For example, the suction pressure P of the compressor 100 S , discharge pressure and speed can be used to determine the compression ratio of the compressor 100 and the mass flow rate of the working fluid through the compressor 100 to indicate the current operating point on the operation map of the compressor. For example, the operation map of the compressor 100 can be stored in the controller 190 (e.g., stored in the memory of the controller 190, stored in the memory of the motor controller 190A) in the form of a lookup table or formula.

[0040] In one embodiment, the magnetic support provided by the bearingless motor 130 to the drive shaft 120 can be adjusted based on the (detected) position of the drive shaft 120. The position of the drive shaft can be detected using the drive shaft position sensor 192A and / or the drive shaft position sensor 192B. For example, when the detected position of the drive shaft 120 differs from its expected position by more than a predetermined amount (e.g., the detected position 120 differs from the expected position by more than a predetermined amount), the bearingless motor 130 can be configured to provide an increased levitation magnetic force, etc. The increased change in the position of the drive shaft 120 can indicate an increased load on the drive shaft 120 (e.g., instability in the drive shaft 120).

[0041] In one embodiment, the magnetic support provided by the bearingless motor 130 to the drive shaft 120 can be adjusted based on the vibration of the compressor. The vibration can indicate the occurrence of abnormal airflow through the compressor 100. The magnetic support provided by the bearingless motor 130 can be adjusted based on the detected vibration of the drive shaft 120. For example, the vibration of the drive shaft (e.g., vibration determined based on the detected change in the position of the drive shaft 120 over time) can be detected using the drive shaft position sensor 192A and / or the drive shaft position sensor 192B. The compressor may include a vibration sensor 196 (e.g., an accelerometer, etc.) for detecting the vibration of the compressor 100 (e.g., vibration of the compressor housing 105, etc.). For example, the bearingless motor 130 may be configured to provide an increased suspension magnetic force when the vibration of the compressor 100 is greater than a predetermined amount.

[0042] In one embodiment, the magnetic support provided by the bearingless motor 130 to the drive shaft 120 can be adjusted based on the pressure of the working fluid within the compressor 100. Changes in the pressure of the working fluid can indicate the occurrence of abnormal airflow through the compressor 100. For example, frequency changes in the pressure of the working fluid within the compressor 100 can indicate the occurrence of stall and / or surge. For example, the compressor 100 may include a pressure sensor (e.g., pressure sensor 194A, pressure sensor 194B, a pressure sensor (not shown) arranged in the flow path between each stage, etc.) to detect the pressure of the working fluid within the compressor (e.g., the dynamic pressure of the working fluid). For example, when the frequency change of the detected pressure of the compressor 100 is greater than a predetermined amount and / or outside a predetermined range, the bearingless motor 130 can be configured to provide an increased suspension magnetic force.

[0043] In one embodiment, the magnetic support provided by the bearingless motor 130 to the drive shaft 120 can be adjusted based on the operation of the suction throttle valves 115A, 115B of the compressor 100. The effect of the suction throttle valves on the flow of the working fluid can indicate whether the airflow through the compressor is abnormal (e.g., actuation of the suction throttle valves having a reduced / different effect on the operation of the compressor 100 indicates abnormal airflow through the compressor 100, the position of the suction throttle valves does not produce the expected flow rate and / or does not cause the compressor to operate). For example, the bearingless motor 130 can be configured to provide increased levitation magnetic force when the position of the suction throttle valves 115A, 115B affects the operation of the compressor 100 differently than expected (e.g., greater than a predetermined amount).

[0044] In one embodiment, the magnetic support provided by the bearingless motor 130 to the drive shaft 120 may be adjusted based on the power to the magnetic bearings 150A, 150B and / or the power to the bearingless motor 130. For example, increased power to the magnetic bearings 150A, 150B and / or to the bearingless motor 130 may indicate instability in the drive shaft 120 and / or abnormal air flow through the compressor (e.g., the drive shaft 120 will rotate more easily during surge). The controller 190 (e.g., the magnetic bearing controller 190B) may detect the power (e.g., the current I ) currently being supplied to the magnetic bearings 150A, 150B. MB ) amount. The controller 190 (eg, the motor controller 190A) may detect the electric power P currently provided to the bearingless motor 130. M (For example, the current I M , voltage V M ) amount. For example, the bearingless motor 130 can be configured to operate when the supplied power exceeds a predetermined maximum power limit or is less than a predetermined minimum power limit (e.g., the supplied current I MB Exceeding the predetermined maximum current, the supplied current IMB Exceeds the predetermined voltage limit or is less than the predetermined minimum voltage, voltage V M Provides increased levitation magnetic force when the voltage exceeds a predetermined maximum voltage or is less than a predetermined minimum voltage.

[0045] The suspension magnetic force (e.g., magnetic support) provided by the bearingless motor 130 can be configured to supplement the magnetic support provided by the magnetic bearings 150A, 150B. The suspension magnetic force provided by the bearingless motor 130 is adjusted during normal operation of the compressor 100. Normal operation refers to operation that is not during startup of the compressor 100 and not during shutdown. The compressor 100 is configured to utilize the magnetic support of the bearingless motor 130 to continue operating during one or more of surge and stall of the compressor 100 (e.g., not initiating shutdown, to maintain its compression / current operation until surge and / or stall ends, etc.).

[0046] Figure 3 FIG. 1 is a block flow diagram of a method 1000 for operating a compressor according to an embodiment. For example, the method 1000 may be used to Figure 1 The compressor 10 in the Figure 2 The compressor 100 includes a drive shaft (eg, drive shaft 120), one or more magnetic bearings (eg, magnetic bearings 150A, 150B), and a bearingless motor (eg, bearingless motor 130). The method 1000 starts at 1010.

[0047] At 1010, the drive shaft is rotated by a bearingless motor to compress the working fluid. At 1010, the bearingless motor generates a rotating magnetic force that causes the drive shaft to rotate. For example, the bearingless motor includes a rotor (e.g., rotor 132) and a stator (e.g., stator 134) fixed to the drive shaft. The stator generates a magnetic field that applies a rotating (magnetic) force to the rotor, which causes the rotor and the drive shaft to which the rotor is fixed to rotate. The rotation of the drive shaft compresses the working fluid in the compressor.

[0048] In one embodiment, the drive shaft rotation at 1010 may include determining a speed of the compressor based on a cooling requirement of a refrigerant circuit (e.g., refrigerant circuit 5) of the compressor at 1012. For example, the speed of the compressor may be selected based on the cooling requirement. Then, at 1014, the bearingless motor applies a magnetic rotational force corresponding to the determined speed to the rotor to rotate the drive shaft at the determined speed. Then, the method 1000 proceeds to 1020.

[0049] At 1020, one or more magnetic bearings provide magnetic support to the drive shaft. The magnetic support can be configured to float the drive shaft. For example, providing magnetic support to the drive shaft at 1020 by one or more magnetic bearings can include sensing the position of the drive shaft via a position sensor for the drive shaft (e.g., drive shaft position sensor 192A, drive shaft position sensor 192B). The magnetic bearings apply a magnetic force to the drive shaft to keep the drive shaft in its desired position. Then, method 1000 proceeds to 1030.

[0050] At 1030, the bearingless motor provides magnetic support to the drive shaft. Providing magnetic support to the drive shaft by the bearingless motor at 1030 includes adjusting the magnetic support provided by the bearingless motor to the drive shaft based on the operation of the compressor at 1032. For example, the amount of magnetic support provided by the bearingless motor is adjusted based on the operation of the compressor at 1032. In one embodiment, the adjustment at 1030 is not to adjust one or more specific directional magnetic forces applied to the drive shaft to provide magnetic support.

[0051] Adjusting the magnetic support provided by the bearingless motor based on the compressor operation at 1032 may include adjusting the magnetic support based on one or more operating conditions of the compressor 100. For example, the one or more operating conditions may include, but are not limited to, a position of a drive shaft, a working fluid pressure within the compressor (e.g., a suction pressure of the compressor, a discharge pressure of the compressor, a dynamic pressure of the working fluid within the compressor), a rotational speed of the compressor (e.g., a rotational speed of the bearingless motor), vibrations of the compressor (e.g., vibrations of the drive shaft, vibrations of the compressor housing, etc.), power to one or more of the magnetic bearings and the bearingless motor, a position of a suction throttling device (e.g., the first suction throttling device 115A, the second suction throttling device 115B), etc.

[0052] In one embodiment, adjusting the magnetic support of the bearingless motor at 1032 may include operating the bearingless motor in a first mode 1034 and operating the bearingless motor in a second mode 1036. For example, based on the operation of the compressor, the bearingless motor is changed between the first mode 1034 and the second mode 1036. In the first mode 1034, the bearingless motor may provide a first amount of magnetic support to the drive shaft. In the second mode 1036, the bearingless motor may provide a second amount of magnetic support to the drive shaft that is greater than the first amount of magnetic support. For example, the bearingless motor is operated in the second mode to provide greater magnetic support to the drive shaft during operation when the drive shaft is less stable. In one example, in the first mode 1034, the bearingless motor provides non-substantial magnetic support to the drive shaft. Non-"substantial" magnetic support may include any incidental support provided when a rotational force is applied to rotate the drive shaft. In another example, the bearingless motor and the bearingless motor may provide magnetic support (e.g., a small amount of magnetic support that is substantially greater than zero) to the drive shaft in the first mode 1034. In one embodiment, the first mode and the second mode may be different parts of the same variable adjustment of the magnetic support provided by the bearingless motor. Normal operation of the compressor (ie, not during startup and not during shutdown) may include operation of the compressor in the first mode 1034 and operation of the compressor in the second mode 1036 .

[0053] In one embodiment, adjusting the magnetic support by the bearingless motor at 1032 may include adjusting the suspension support based on an operating map of the compressor. For example, the magnetic support provided by the bearingless motor is adjusted based on a suction pressure of the compressor (e.g., a pressure of a working fluid flowing into the compressor), a discharge pressure of the working fluid, and a rotational speed of the compressor. For example, when the compressor 100 is operated in one or more predetermined regions of the operating map (e.g., one or more regions that cause an increased radial load on the drive shaft 120, one or more regions that cause an increased axial load on the drive shaft 120), the bearingless motor provides increased magnetic support (e.g., operating in a second mode 1036). For example, the bearingless motor 130 is configured to provide less magnetic support when the compressor is not operating in one or more predetermined regions of the operating map (e.g., operating in a first operating mode 1034).

[0054] Adjustment of the magnetic force of the bearingless motor at 1032 may include adjusting the magnetic support based on the position of the drive shaft. In one embodiment, the adjustment at 1032 includes detecting the position of the drive shaft using a drive shaft position sensor (e.g., drive shaft position sensor 192A, drive shaft position sensor 192B), and adjusting the suspension magnetic force based on the detected position of the drive shaft. For example, when the detected position of the drive shaft changes from its desired position by more than a predetermined amount (e.g., the detected position of the drive shaft differs from the desired position by a predetermined amount, the position change of the drive shaft is greater than a predetermined amount from the desired position, etc.), the bearingless motor provides increased magnetic support. The increased change in the drive shaft position may indicate that the load on the drive shaft exceeds the magnetic support provided by one or more magnetic bearings at 1020. In one embodiment, the adjustment at 1032 may be based on both the operational mapping and the detected position of the drive shaft as described above.

[0055] It should be understood that in other embodiments, the method 1000 may be based on Figure 1 The HVACR system 1 shown and / or based on Figure 2 The compressor 100 shown and / or the compressor 100 described above may be modified. For example, in one embodiment, the method 1000 may be configured with the same one or more drive shaft position sensors for operating magnetic bearings and bearingless motors.

[0056] Various aspects: Any one of aspects 1 to 9 may be combined with any one of aspects 10 to 20.

[0057] Aspect 1. A compressor comprising: a drive shaft; a bearingless motor configured to rotate the drive shaft to compress a working fluid; one or more magnetic bearings for magnetically supporting the drive shaft as the drive shaft rotates; and a controller for the bearingless motor, the controller being configured to adjust the magnetic support provided to the drive shaft by the bearingless motor as the drive shaft rotates based on the operation of the compressor.

[0058] Aspect 2. The compressor according to Aspect 1 further includes: one or more sensors for detecting one or more operating conditions of the compressor, wherein the controller is configured to increase the amount of magnetic support provided by the bearingless motor based on the detected one or more operating conditions of the compressor.

[0059] Aspect 3. The compressor according to aspect 2, wherein the one or more operating conditions include one or more of a suction pressure of the compressor, a discharge pressure of the compressor, and a position of a drive shaft.

[0060] Aspect 4. The compressor according to any one of aspects 1 to 3, wherein the bearingless motor is configured to selectively provide magnetic support to the drive shaft based on the operation of the compressor.

[0061] Aspect 5. The compressor according to any one of Aspects 1 to 4 further includes: one or more drive shaft position sensors for detecting the position of the drive shaft, wherein the controller adjusts the magnetic support of the bearingless motor based on the position of the drive shaft detected by the one or more drive shaft position sensors.

[0062] Aspect 6. The compressor of any one of aspects 1 to 5, wherein adjusting the magnetic support provided by the bearingless motor occurs during normal operation of the compressor.

[0063] Aspect 7. A compressor according to any one of Aspects 1 to 6, wherein the one or more magnetic bearings are configured to provide radial support to the drive shaft when the drive shaft rotates, and the magnetic support provided by the bearingless motor includes radial magnetic support of the drive shaft when the drive shaft rotates.

[0064] Aspect 8. A compressor according to Aspect 7, wherein the controller is configured to adjust the magnetic support provided by the bearingless motor to the drive shaft, including: the controller is configured to increase the radial magnetic support provided by the bearingless motor to the drive shaft in response to an increase in the radial load on the drive shaft.

[0065] Aspect 9. A compressor according to any one of Aspects 1 to 8, wherein the controller is configured to receive a cooling demand, determine the rotational speed of the bearingless motor based on the cooling demand, and control the bearingless motor to generate a rotating magnetic force corresponding to the determined rotational speed and generate a suspension magnetic force to provide magnetic support to the drive shaft.

[0066] Aspect 10. A method for operating a compressor, the compressor comprising a drive shaft, one or more magnetic bearings and a bearingless motor, the method comprising: utilizing the bearingless motor to rotate the drive shaft to compress a working fluid; utilizing one or more magnetic bearings to magnetically support the rotating drive shaft; and utilizing the bearingless motor to magnetically support the drive shaft, including adjusting the magnetic support provided to the rotating drive shaft by the bearingless motor based on the operation of the compressor.

[0067] Aspect 11. A method according to Aspect 10, wherein adjusting the magnetic support provided by the bearingless motor to the drive shaft based on the operation of the compressor includes: detecting one or more operating conditions of the compressor using one or more sensors, and adjusting the magnetic support provided by the bearingless motor to the drive shaft includes: adjusting the magnetic support provided by the bearingless motor based on one or more operating conditions detected by one or more sensors.

[0068] Aspect 12. The method according to aspect 11, wherein the one or more operating conditions include one or more of a suction pressure of the compressor, a discharge pressure of the compressor, and a position of the drive shaft.

[0069] Aspect 13. A method according to any one of aspects 10 to 12, wherein the magnetic support is selectively provided to the rotating drive shaft by a bearingless motor.

[0070] Aspect 14. The method of any one of aspects 10 to 13, wherein adjusting the magnetic support provided by the bearingless motor occurs during normal operation of the compressor.

[0071] Aspect 15. The method according to any one of aspects 10 to 14, wherein magnetically supporting the drive shaft using one or more magnetic bearings comprises radially magnetically supporting the rotating drive shaft, and

[0072] Magnetically supporting the drive shaft using the bearingless motor includes radially magnetically supporting the rotating drive shaft.

[0073] Aspect 16. The method of aspect 15, wherein adjusting the magnetic support provided by the bearingless motor to the drive shaft comprises increasing the radial magnetic support provided by the bearingless motor in response to an increased radial load on the drive shaft.

[0074] Aspect 17. A method according to any one of aspects 10-16, wherein

[0075] Rotating the drive shaft using the bearingless motor includes: determining a rotation speed of the bearingless motor based on a cooling requirement and generating a rotating magnetic force corresponding to the determined rotation speed, and

[0076] Magnetically supporting the drive shaft using a bearingless motor includes the bearingless motor generating a levitation magnetic force that provides magnetic support to the drive shaft.

[0077] Aspect 18. A method according to any one of Aspects 10 to 17, wherein magnetically supporting the drive shaft using a bearingless motor includes: operating the bearingless motor in a first mode and operating the bearingless motor in a second mode, wherein a smaller amount of magnetic support is provided by the bearingless motor in the first mode.

[0078] Aspect 19. The method of aspect 18, wherein adjusting the magnetic support provided by the bearingless motor to the drive shaft comprises adjusting the bearingless motor between operation in the first mode and operation in the second mode based on operation of the compressor.

[0079] Aspect 20. The method of aspect 18, wherein operating the bearingless motor in the first mode includes providing insubstantial magnetic support to the drive shaft.

[0080] The terms used herein are intended to describe specific embodiments and are not intended to be limiting. Unless otherwise expressly stated, the terms "a", "the" and "said" also include plural forms. When used herein, the terms "include" and / or "comprise" indicate the presence of features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements and / or components. In one embodiment, "fixed" as described herein may refer to "directly fixed".

[0081] With respect to the foregoing description, it should be understood that changes in detail may be made, particularly in the construction materials and the shapes, sizes and arrangements of the components, without departing from the scope of the present disclosure. This specification and the described embodiments are exemplary only, and the actual scope and spirit of the present disclosure are specified by the appended claims.

Claims

1. A compressor, characterized in that: include: Drive shaft; a bearingless motor configured to rotate the drive shaft to compress a working fluid; one or more magnetic bearings for magnetically supporting the drive shaft as it rotates; and A controller for the bearingless motor is configured to adjust magnetic support provided by the bearingless motor to the drive shaft as the drive shaft rotates based on operation of the compressor.

2. The compressor according to claim 1, characterized in that Also includes: one or more sensors for detecting one or more operating conditions of the compressor; Wherein the controller is configured to increase the amount of the magnetic support provided by the bearingless motor based on one or more detected operating conditions of the compressor.

3. The compressor according to claim 2, characterized in that The one or more operating conditions include one or more of a suction pressure of the compressor, a discharge pressure of the compressor, and a position of the drive shaft.

4. The compressor according to claim 1, characterized in that The bearingless motor is configured to selectively provide the magnetic support to the drive shaft based on operation of the compressor.

5. The compressor according to claim 1, characterized in that Also includes: one or more drive shaft position sensors for detecting the position of the drive shaft; Wherein the controller adjusts the magnetic support of the bearingless motor based on a position of the drive shaft detected by the one or more drive shaft position sensors.

6. The compressor according to claim 1, characterized in that Adjusting the magnetic support provided by the bearingless motor occurs during normal operation of the compressor.

7. The compressor according to claim 1, characterized in that The one or more magnetic bearings are configured to provide radial support to the drive shaft as the drive shaft rotates, and the magnetic support provided by the bearingless motor includes radial magnetic support of the drive shaft as the drive shaft rotates.

8. The compressor according to claim 7, characterized in that The controller being configured to adjust the magnetic support provided by the bearingless motor to the drive shaft includes the controller being configured to increase radial magnetic support provided by the bearingless motor to the drive shaft in response to an increase in radial load on the drive shaft.

9. The compressor according to claim 1, characterized in that The controller is configured to receive a cooling requirement, determine a rotation speed of the bearingless motor based on the cooling requirement, and control the bearingless motor to generate a rotational magnetic force corresponding to the determined rotation speed and a levitation magnetic force that provides the magnetic support to the drive shaft.

10. A method of operating a compressor, characterized in that The compressor comprises a drive shaft, a bearingless motor and one or more magnetic bearings, the method comprising: rotating the drive shaft using the bearingless motor to compress the working fluid; magnetically supporting the drive shaft for rotation using the one or more magnetic bearings; and The drive shaft is magnetically supported using the bearingless motor, including adjusting the magnetic support provided by the bearingless motor to the rotating drive shaft based on operation of the compressor.

11. The method according to claim 10, characterized in that Adjusting the magnetic support provided by the bearingless motor to the drive shaft based on the operation of the compressor includes: detecting one or more operating conditions of the compressor using one or more sensors, and Adjusting the magnetic support provided by the bearingless motor to the drive shaft includes adjusting the magnetic support provided by the bearingless motor based on one or more operating conditions detected by the one or more sensors.

12. The method according to claim 11, characterized in that The one or more operating conditions include one or more of a suction pressure of the compressor, a discharge pressure of the compressor, and a position of the drive shaft.

13. The method according to claim 10, characterized in that The magnetic support is selectively provided to the rotating drive shaft by the bearingless motor.

14. The method according to claim 10, characterized in that Adjusting the magnetic support provided by the bearingless motor occurs during normal operation of the compressor.

15. The method according to claim 10, characterized in that Magnetically supporting the drive shaft with the one or more magnetic bearings includes radially magnetically supporting the drive shaft for rotation, and Magnetically supporting the drive shaft with the bearingless motor includes radially magnetically supporting the drive shaft for rotation.

16. The method according to claim 15, characterized in that Adjusting the magnetic support provided by the bearingless motor to the drive shaft includes increasing the radial magnetic support provided by the bearingless motor in response to an increased radial load on the drive shaft.

17. The method according to claim 10, characterized in that Rotating the drive shaft using the bearingless motor includes: determining a rotation speed of the bearingless motor based on cooling requirements and generating a rotating magnetic force corresponding to the determined rotation speed, and Magnetically supporting the drive shaft using the bearingless motor includes the bearingless motor generating a levitation magnetic force that provides the magnetic support to the drive shaft.

18. The method according to claim 10, characterized in that Magnetically supporting the drive shaft with the bearingless motor includes operating the bearingless motor in a first mode with a lesser amount of magnetic support provided by the bearingless motor and operating the bearingless motor in a second mode.

19. The method according to claim 18, characterized in that Adjusting the magnetic support provided by the bearingless motor to the drive shaft includes adjusting the bearingless motor between operation in the first mode and operation in the second mode based on operation of the compressor.

20. The method according to claim 18, characterized in that Operating the bearingless motor in the first mode includes providing insubstantial magnetic support to the drive shaft.

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