KR20200023836A - Method and apparatus for compressor - Google Patents

Abstract

The present invention relates to a compressor and a control method thereof. The compressor comprises: at least one impeller configured to suction a refrigerant in an axial direction to compressor the refrigerant in a centrifugal direction; a rotary shaft connected to the impeller and a motor which rotates the impeller; at least two thrust bearings configured to limit radial vibration of the rotary shaft; a gap sensor configured to sense a distance with the rotary shaft; and a control unit configured to determine a surge generation condition based on information received from the gap sensor. The control unit can adjust amounts of currents supplied to the thrust bearings when the surge generation condition is satisfied so that the rotary shaft can be eccentrically positioned in the opposite direction of the impeller from a reference position.

Description

Compressor and its control method {Method and apparatus for compressor}

The present invention relates to a compressor and a control method of the compressor.

In general, the chiller system is to supply cold water to the cold water demand source, characterized in that the heat exchange between the refrigerant circulating the refrigeration system and the cold water circulating between the cold water demand source and the refrigeration system to cool the cold water. Such a chiller system is a large capacity facility and can be installed in a large building.

Conventional chiller system is disclosed in Korea Patent Publication No. 10-1084477. In the chiller system as disclosed in the publication, the surge phenomenon caused by the rotary motion compressor is problematic. Surge occurs when the compression ratio of the compressor is high compared to the flow rate of the refrigerant, and refers to the phenomenon that the flow of the refrigerant becomes irregular because the rotating body of the compressor is idle. In the event of this surge, the compressor will not produce pressure greater than the pressure resistance of the system.

As a result, during a surge phenomenon, a reverse flow of the refrigerant occurs repeatedly, causing frequent damage to the compressor.

Therefore, it is required to find a way to prevent damage to the compressor due to the surge phenomenon in the chiller system.

The problem to be solved by the present invention is to prevent damage to the compressor when a surge generated in the compressor occurs.

Another object of the present invention is to prevent the rotational shaft generated at the time of surge occurrence in one direction with little force and little current.

The objects of the present invention are not limited to the above-mentioned objects, and other objects that are not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, the compressor according to the embodiment of the present invention is characterized in that, when the generation of surge is expected to move the rotating shaft in the impeller direction.

 Specifically, the present invention is one or more impeller to suck the refrigerant in the axial direction to compress in the centrifugal direction; A rotating shaft to which the impeller and the motor for rotating the impeller are connected; At least two thrust bearings for limiting the oscillation of the axis of rotation; A gap sensor for sensing a distance from the rotating shaft; And a controller configured to determine a surge generation condition based on the information received from the gap sensor, wherein the controller adjusts an amount of current supplied to the thrust bearings when the surge generation condition is satisfied. It characterized in that the eccentric position in the opposite direction of the impeller in the reference position.

Here, the thrust bearing may include a first thrust bearing and a second thrust bearing positioned closer to the impeller than the first thrust bearing and having at least a portion of the rotating shaft positioned between the first thrust bearing. have.

When the surge generation condition is satisfied, the controller may supply a current only to the first thrust bearing among the first and second thrust bearings.

When the surge generation condition is satisfied, the controller may adjust the amount of current supplied to the first thrust bearing to be greater than the amount of current supplied to the second thrust bearing.

The rotary shaft may further include a rotary shaft blade extending in a radial direction of the rotary shaft, and the rotary shaft blade may be positioned between the first thrust bearing and the second thrust bearing.

The gap sensor may measure the axial movement of the rotation axis.

When the position of the rotating shaft measured by the gap sensor is out of the normal position range, the controller may determine that the surge occurs.

When the position of the rotating shaft measured by the gap sensor is located within the normal position range, the controller may determine that the surge is not generated.

The controller may equally adjust the amount of current supplied to the first thrust bearing and the amount of current supplied to the second thrust bearing when the surge non-occurrence condition is satisfied.

It may further include a plurality of magnetic bearings for supporting the rotation axis to be rotatable in the air.

In addition, the present invention (a) measuring the distance between the gap sensor and the rotation axis; (B) determining a surge occurrence condition based on a distance between the gap sensor and the rotation axis; And (c) positioning said rotational axis eccentrically in the opposite direction of the impeller at a reference position by adjusting the amount of current supplied to the thrust bearings when the surge generation condition is satisfied.

When the surge non-occurrence condition is satisfied, the method may further include (d) adjusting the amount of current supplied to the thrust bearings to position the rotational shaft at the reference position.

In step (c), the amount of current supplied to the thrust bearing positioned relatively far from the impeller among the two thrust bearings may be adjusted to be greater than the amount of current supplied to the thrust bearing positioned close to the impeller.

Specific details of other embodiments are included in the detailed description and the drawings.

According to the compressor and the control method of the present invention has one or more of the following effects.

First, by preventing the surge phenomenon, there is an advantage of preventing damage to the compressor.

Second, the present invention, in anticipation of the occurrence of a surge phenomenon in advance, adjusts the position of the rotary shaft, there is also an advantage that can be quickly prevented from the eccentricity of the rotary shaft in the direction of the surge when the surge occurs.

Third, the present invention can move the position of the rotating shaft in advance before the surge occurs, it is possible to prevent damage to the compressor with a force less than that in the reference position at the time of the surge occurs, to reduce the volume of the thrust bearing, the amount of current There is also an advantage to reduce.

The effects of the present invention are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

1 shows a chiller system in one embodiment of the present invention.
2 illustrates a structure of a compressor according to an embodiment of the present invention.
3 illustrates a case where a compressor does not generate a surge according to an embodiment of the present invention.
4 illustrates a case where a compressor generates a surge condition according to an embodiment of the present invention.
5 is a block diagram illustrating a relationship between components connected to a controller.
6 illustrates a control method of a compressor according to an embodiment of the present invention.

Advantages and features of the present invention, and methods for achieving them will be apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be embodied in various different forms, and the present embodiments merely make the disclosure of the present invention complete, and those of ordinary skill in the art to which the present invention belongs. It is provided to fully inform the person having the scope of the invention, which is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

The spatially relative terms " below ", " beneath ", " lower ", " above ", " upper " It can be used to easily describe the correlation of components with other components. Spatially relative terms are to be understood as terms that include different directions of components in use or operation in addition to the directions shown in the figures. For example, when flipping a component shown in the drawing, a component described as "below" or "beneath" of another component may be placed "above" the other component. Can be. Thus, the exemplary term "below" can encompass both an orientation of above and below. The components can be oriented in other directions as well, so that spatially relative terms can be interpreted according to the orientation.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. In this specification, the singular also includes the plural unless specifically stated otherwise in the phrase. As used herein, "comprises" and / or "comprising" refers to a component, step, and / or operation that excludes the presence or addition of one or more other components, steps, and / or operations. I never do that.

Unless otherwise defined, all terms used in the present specification (including technical and scientific terms) may be used in a sense that can be commonly understood by those skilled in the art. In addition, the terms defined in the commonly used dictionaries are not ideally or excessively interpreted unless they are specifically defined clearly.

In the drawings, the thickness or size of each component is exaggerated, omitted, or schematically illustrated for convenience and clarity of description. In addition, the size and area of each component does not necessarily reflect the actual size or area.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

Hereinafter, the present invention will be described with reference to the drawings for describing the compressor according to embodiments of the present invention.

1 shows a chiller system equipped with a compressor 100 of the present invention. On the other hand, the compressor 100 according to an embodiment of the present invention may not only function as part of the chiller system but may also be included in an air conditioner and may be included in any device that compresses gaseous substances.

 Referring to FIG. 1, a chiller system 1 according to an embodiment of the present invention includes a compressor 100 configured to compress a refrigerant, and a condenser 200 for condensing the refrigerant by heat-exchanging the refrigerant compressed in the compressor 100 and the cooling water. ), An expander 300 that expands the refrigerant condensed in the condenser 200, and an evaporator 400 formed to heat the refrigerant expanded in the expander 300 and cold water to cool the cold water together with the evaporation of the refrigerant.

 In addition, the chiller system 1 according to an embodiment of the present invention is a cooling water unit 600 for heating the cooling water through heat exchange between the refrigerant and the cooling water compressed in the condenser 200, and the expanded in the evaporator 400 The air conditioning unit 500 further cools the cold water through heat exchange between the refrigerant and the cold water.

 The condenser 200 provides a place for heat-exchanging the high pressure refrigerant compressed by the compressor 100 with the cooling water introduced from the cooling water unit 600. The high pressure refrigerant is condensed through heat exchange with cooling water.

 The condenser 200 may be composed of a shell-tube type heat exchanger. Specifically, the high pressure refrigerant compressed by the compressor 100 is introduced into the condensation space 230 corresponding to the internal space of the condenser 200 through the condenser connection flow path 150. In addition, the condensation space 230 includes a cooling water flow path 210 through which the cooling water flowing from the cooling water unit 600 may flow.

 The cooling water channel 210 includes a cooling water inflow channel 211 through which cooling water is introduced from the cooling water unit 600, and a cooling water discharge channel 212 through which cooling water is discharged to the cooling water unit 600. The coolant introduced into the coolant inflow passage 211 is heat-exchanged with the refrigerant in the condensation space 230 and then passes through the coolant connection passage 240 provided at one end or the outside of the condenser 200 to the coolant discharge passage 212. Inflow.

 The cooling water unit 600 and the condenser 200 are connected via the cooling water tube 220. The cooling water tube 220 may be made of a material such as rubber so that the cooling water flows between the cooling water unit 600 and the condenser 200 as well as the passage of the cooling water.

The cooling water tube 220 includes a cooling water inlet tube 221 connected to the cooling water inlet passage 211 and a cooling water discharge tube 222 connected to the cooling water discharge passage 212. Looking at the flow of the cooling water as a whole, the cooling water after the heat exchange with the air or liquid in the cooling water unit 600 is introduced into the condenser 200 through the cooling water inlet tube 221. The coolant introduced into the condenser 200 flows into the condenser 200 while passing through the coolant inflow passage 211, the coolant connection passage 240, and the coolant discharge passage 212 provided in the condenser 200. After the heat exchange with the refrigerant is passed through the coolant discharge tube 222 to the coolant unit 600 again.

 On the other hand, the cooling water absorbing the heat of the refrigerant through heat exchange in the condenser 200 may be air-cooled in the cooling water unit (600). The coolant unit 600 is cooled in the coolant inlet pipe 610 and the coolant unit 600, which is an inlet through which the coolant absorbed heat through the main body 630 and the coolant discharge tube 222, and then discharges the coolant. It is composed of a cooling water discharge pipe 620 which is an outlet.

 The cooling water unit 600 may use air to cool the cooling water introduced into the main body 630. In detail, the main body 630 includes an air outlet 631 having a fan for generating air flow and an air inlet 632 corresponding to an inlet for introducing air into the body 630. do.

 The air discharged after the heat exchange at the air discharge port 631 may be used for heating. After the heat exchange in the condenser 200, the refrigerant is condensed and accumulated in the condensation space 230. The depleted refrigerant flows into the expander 300 after being introduced into the refrigerant box 250 provided in the condensation space 230.

 The refrigerant box 250 is introduced into the refrigerant inlet 251, and the introduced refrigerant is discharged into the evaporator connection passage 260. The evaporator connection passage 260 may include an evaporator connection passage inlet 261, and the evaporator connection passage inlet 261 may be located below the refrigerant box 250.

 The evaporator 400 includes an evaporation space 430 in which heat exchange occurs between the refrigerant expanded in the expander 300 and the cold water. The refrigerant passing through the expander 300 in the evaporator connection passage 260 is connected to the refrigerant injection device 450 provided in the evaporator 400, and opens the refrigerant injection hole 451 provided in the refrigerant injection device 450. It is spread evenly through the evaporator 400.

 In addition, the evaporator 400 has a cold water flow passage 410 including a cold water inflow passage 411 through which cold water is introduced into the evaporator 400 and a cold water discharge passage 412 through which cold water is discharged to the outside of the evaporator 400. do.

 Cold water is introduced or discharged through the cold water tube 420 communicated with the air conditioning unit 500 provided outside the evaporator 400. Cold water tube 420 is a passage for the cold water inlet after the heat exchange in the cold water inlet tube 421 and the evaporator 400, the cold water inside the air conditioning unit 500 toward the evaporator 400 Phosphorus cold water discharge tube (422). That is, the cold water inflow tube 421 communicates with the cold water inflow passage 411 and the cold water discharge tube 422 communicates with the cold water discharge passage 412.

 Looking at the flow of cold water, through the air conditioning unit 500, the cold water inlet tube 421, the cold water inlet 411, one end of the evaporator 400 or the cold water connection passage 440 provided outside the evaporator 400 After passing through), it passes through the cold water discharge passage 412, the cold water discharge tube 422 to the air conditioning unit 500 again.

 The air conditioning unit 500 cools the cold water through the refrigerant. The cooled cold water absorbs the heat of the air in the air conditioning unit 500 to enable indoor cooling. The air conditioning unit 500 includes a cold water inlet tube 520 in communication with the cold water inlet tube 421 and a cold water inlet tube 510 in communication with the cold water outlet tube 422. After the heat exchange in the evaporator 400, the refrigerant flows back into the compressor 100 through the compressor 100 connection passage 460.

2 illustrates a centrifugal compressor 100 (aka, a turbo compressor) according to an embodiment of the present invention.

 The compressor 100 according to FIG. 2 is connected to one or more impellers 120, an impeller 120, and a motor 130 that rotates the impeller 120 to suck the refrigerant in the axial direction Ax and compress it in the centrifugal direction. The bearing shaft 140 and the rotating shaft 110 including a plurality of magnetic bearings 141 supporting the rotating shaft 110, the rotating shaft 110 so as to be rotatable in the air, and a bearing housing 142 supporting the magnetic bearing 141. It includes a gap sensor 70 for sensing the distance to the) and the thrust bearing 160 for limiting the vibration of the rotating shaft 110 in the axial direction (Ax).

 Impeller 120 is generally composed of one or two stages may be composed of a plurality of stages. It rotates by the rotating shaft 110, and serves to make the refrigerant to high pressure by compressing the refrigerant introduced in the axial direction (Ax) by rotating in the centrifugal direction.

 The motor 130 may have a structure that transmits the rotational force to the rotation shaft 110 by a belt (not shown) having a separate rotation shaft 110 and the rotation shaft 110, in one embodiment of the present invention, the motor ( 13 is composed of a stator (not shown) and the rotor 112 to rotate the rotating shaft (110).

The rotating shaft 110 is connected to the impeller 120 and the motor 13. The rotating shaft 110 extends in the left and right directions of FIG. 2. Hereinafter, the axial direction Ax of the rotation shaft 110 means the left and right directions. The rotating shaft 110 preferably includes a metal so as to be moved by the magnetic force of the magnetic bearing 141 and the thrust bearing.

In order to prevent the thrust bearing 160 from oscillating in the axial direction Ax (left and right directions) of the thrust bearing 160, it is preferable that the rotary shaft 110 has a constant area in a plane perpendicular to the axial direction Ax. . Specifically, the rotary shaft 110 may further include a rotary shaft blade 111 that provides a sufficient magnetic force to move the rotary shaft 110 by the magnetic force of the thrust bearing 160. The rotary shaft blade 111 may have a larger area than the cross-sectional area of the rotary shaft 110 in a plane perpendicular to the axial direction Ax. The rotary shaft blade 111 may be formed to extend in the rotational radial direction of the rotary shaft 110.

 The magnetic bearing 141 and the thrust bearing 160 are made of a conductor and the coil 143 is wound. The current flowing through the wound coil 143 serves as a magnet.

 A plurality of magnetic bearings 141 are provided to surround the rotating shaft 110 around the rotating shaft 110, and the thrust bearing 160 extends in the rotational radial direction of the rotating shaft 110. It is provided adjacent to.

 The magnetic bearing 141 allows the rotating shaft 110 to rotate without friction in a state in which it is suspended in the air. To this end, at least three magnetic bearings 141 should be provided around the rotating shaft 110, and each of the magnetic bearings 141 must be installed in a balanced manner with respect to the rotating shaft 110.

In the exemplary embodiment of the present invention, four magnetic bearings 141 are provided to be symmetric about the rotation shaft 110, and the rotation shaft 110 is formed by a magnetic force generated by coils wound on the respective magnetic bearings 141. This will support the air. Due to the rotation of the rotating shaft 110 in the air, unlike the conventional invention is equipped with a bearing, the energy lost due to friction is reduced.

Meanwhile, the compressor 100 may further include a bearing housing 142 for supporting the magnetic bearing 141. A plurality of magnetic bearings 141 is provided, and is provided with a gap so as not to contact the rotating shaft 110.

 The plurality of magnetic bearings 141 are installed at at least two points of the rotation shaft 110. The two points correspond to different points along the longitudinal direction of the rotation shaft 110. Since the rotation shaft 110 corresponds to a straight line, the rotation shaft 110 must be supported at at least two points to prevent vibration in the circumferential direction.

 Looking at the flow of the refrigerant, the refrigerant introduced into the compressor 100 through the connection path 460 of the compressor 100 is compressed to the circumferential direction by the action of the impeller 120 and then discharged to the condenser connection channel 150. The connection passage 460 of the compressor 100 is connected to the compressor 100 so that refrigerant may be introduced in a direction perpendicular to the rotation direction of the impeller 120.

The thrust bearing 160 restricts the rotational shaft 110 from moving in the axial direction Ax, and the rotational shaft 110 moves in the direction of the impeller 120 when a surge occurs, and thus the other configuration of the compressor 100 is different. It prevents the rotation of the rotating shaft 110.

Specifically, the thrust bearing 160 is composed of a first thrust bearing 161 and a second thrust bearing 162 and is disposed to surround the rotary shaft blade 111 in the axial direction Ax of the rotary shaft 110. That is, the first thrust bearing 161, the rotary shaft blade 111, and the second thrust bearing 162 are disposed in the axial direction Ax of the rotary shaft 110.

More specifically, the second thrust bearing 162 is located closer to the impeller 120 than the first thrust bearing 161, and the first thrust bearing 161 is farther from the impeller 120 than the second thrust bearing. At least a portion of the rotation shaft 110 is positioned between the first thrust bearing 161 and the second thrust bearing 162. Preferably, the rotary shaft blade 111 is positioned between the first thrust bearing 161 and the second thrust bearing 162.

 Therefore, the first thrust bearing 161 and the second thrust bearing 162 may minimize the vibration of the rotary shaft 110 in the direction of the rotary shaft 110 by the operation of the rotary shaft blade 111 and the magnetic force having a large area. It works.

The gap sensor 70 measures the movement of the axis Ax (left and right) of the rotation shaft 110. Of course, the gap sensor 70 may measure the movement of the rotary shaft 110 in the vertical direction (direction perpendicular to the axial direction Ax). Of course, the gap sensor 70 may include a plurality of gap sensors 70.

For example, the gap sensor 70 includes a first gap sensor 710 for measuring the vertical movement of the rotary shaft 110 and a second gap sensor 720 for measuring the horizontal movement of the rotary shaft 110 in the horizontal direction. . The second gap sensor 720 may be spaced apart from one end of the axial direction Ax of the rotation shaft 110 in the axial direction Ax.

The force of the thrust bearing 160 is inversely proportional to the square of the distance and is proportional to the square of the current. When a surge occurs in the rotary shaft 110, the thrust is generated in the direction of the impeller 120 (right direction). The force generated in the right direction should be pulled by the maximum force by using the magnetic force of the thrust bearing 160, so that the position of the rotating shaft 110 is located in the middle of the two thrust bearings 160 (reference position C0). In this case, it is difficult to move the rotary shaft 110 to the reference position C0 quickly in response to the rapid axis movement.

Since the force of the thrust in the direction of the impeller 120 generated on the rotating shaft 110 is considerably strong, when it is located at the reference position C0, the supply amount of current is increased to increase the magnetic force of the thrust bearing 160, or the thrust bearing There is a problem of increasing the size of 160.

The present invention is to solve the above problems, if the surge is expected to be in advance to position the rotating shaft 110 in the direction opposite to the direction in which the thrust is generated.

In detail, the controller 700 determines a surge generation condition based on the information received from the gap sensor 70. The controller 700 may determine the surge generation condition when the position of the rotation shaft 110 measured by the gap sensor 70 is out of the normal position range (-C1 to + C1). In addition, when the position of the rotation shaft 110 measured by the gap sensor 70 is located within the normal position range (-C1 to + C1), the controller 700 may determine that the surge is not generated.

Here, the normal position range (-C1 to + C1) of the rotation shaft 110 refers to an area within a predetermined distance in the left and right directions with respect to the reference position C0 of the rotation shaft 110. The normal position range (-C1 to + C1) of the rotary shaft 110 causes the rotary shaft 110 to vibrate in the axial direction Ax due to various environmental and peripheral factors when the rotary shaft 110 rotates. It is the range where vibration is judged to be in a steady state. The normal position range (-C1 ~ + C1) is an experimental value, the normal position range (-C1 ~ + C1) based on the kurtosis or skewness of the position of the rotation axis 110 value You can also decide. There is no limit on how to determine the normal position range (-C1 to + C1).

When the surge generation condition is satisfied, the control unit 700 adjusts the amount of current supplied to the thrust bearings 160 so that the rotation shaft 110 is eccentric in the opposite direction of the impeller 120 at the reference position C0. Can be located. The position at which the rotary shaft 110 is eccentric means that the rotary shaft blade 111 is located between the first thrust bearing 160 and the reference position C0.

Therefore, a surge may occur afterwards to have a buffering time in which the rotating shaft 110 moves rapidly in the direction of the impeller 120, and due to the increase in the amount of current, the rotating shaft 110 may be moved in the normal position range (-C1 to + C1). It is easy to control.

In detail, when the surge generation condition is satisfied, the controller 700 may supply a current only to the first thrust bearing 161 among the first and second thrust bearings 162. As another example, when the surge generation condition is satisfied, the controller 700 may adjust the amount of current supplied to the first thrust bearing 161 to be greater than the amount of current supplied to the second thrust bearing 162.

Since the surge generation condition is satisfied, the controller 700 eccentrically rotates the rotation shaft 110 in the opposite direction of the impeller 120, and then controls the position of the rotation shaft 110 to be fixed to the eccentric position for a predetermined time. That is, the controller 700 may increase the amount of current supplied to the first thrust bearing 161 when a surge occurs after the rotation shaft 110 is eccentric in the opposite direction to the impeller 120. The controller 700 moves the rotary shaft 110 back to the reference position C0 when the rotary shaft 110 is eccentric in the opposite direction to the impeller 120 and the vibration width is maintained below a predetermined reference based on the eccentric position. You can also

The controller 700 may equally adjust the amount of current supplied to the first thrust bearing 161 and the amount of current supplied to the second thrust bearing 162 when the surge non-occurrence condition is satisfied. Alternatively, the control unit 700 adjusts the amount of current supplied to the first thrust bearing 161 and the second thrust bearing 162 when the surge non-occurrence condition is satisfied, so that the rotation shaft 110 is in the reference position ( Control to be located at C0).

5 shows an operation block diagram of the control unit 700. The controller 700 controls the power amplifier 730 to amplify the magnitude of the current applied to the gap sensor 70, the magnetic bearing 141, and the thrust bearing 160.

 The power amplifier 730 may be controlled to adjust the magnitude of the current applied to the magnetic bearing 141, and the position change of the rotation shaft 110 may be grasped according to the magnitude of the current using the gap sensor 70.

 The value measured by the gap sensor 70 is stored in the storage unit 740. Data such as the reference position C0, the normal position range (-C1 to + C1), and the eccentric position may be stored in the storage unit 740 in advance. When determining a surge occurrence condition in the future, the measured value and the value stored in the storage unit 740 may be compared with each other to determine whether the surge generation condition.

 Meanwhile, in one embodiment of the present invention, a control method of the compressor 100 is provided. 6 shows a control method step showing an embodiment of the present invention.

In the method of controlling the compressor 100 of the present invention, the step (a) of measuring the distance between the gap sensor 70 and the rotating shaft 110 and the surge generation condition based on the distance between the gap sensor 70 and the rotating shaft 110 are performed. In step (b) of determining, when the surge generation condition is satisfied, by adjusting the amount of current supplied to the thrust bearings 160, the rotating shaft 110 in the opposite direction of the impeller 120 at the reference position (C0) It may include the step (c) for eccentric positioning.

In addition, the present invention further includes the step (d) of positioning the rotating shaft 110 at the reference position C0 by adjusting the amount of current supplied to the thrust bearings 160 when the surge non-occurrence condition is satisfied. can do.

 Specifically, step (a) (S10) measures the distance between the rotary shaft 110 and the gap sensor 70 (S10). In addition, the data measured by the gap sensor 70 is stored in the control unit 700 (S20). In more detail, the storage unit 740 may be stored in the storage unit 740 connected to the control unit 700.

 Thereafter, the surge generation condition is determined based on the distance between the gap sensor 70 and the rotation shaft 110 (S50). Surge generation conditions are as described above. In detail, the controller 700 compares the data stored in the storage unit 740 with the measured value of the gap sensor 70 to determine a surge occurrence condition or a surge non-occurrence condition.

When the surge generation condition is satisfied, the control unit 700 adjusts the amount of current supplied to the thrust bearings 160 so that the rotation shaft 110 is eccentric in the opposite direction of the impeller 120 at the reference position C0. Position it (S60). In detail, the control unit 700 controls the amount of current supplied to the thrust bearing 160 positioned relatively far from the impeller 120 among the two thrust bearings 160, and the thrust bearing 160 positioned close to the impeller 120. It can be adjusted to be larger than the amount of current supplied to More specifically, when the surge generation condition is satisfied, the controller 700 may supply a current only to the first thrust bearing 161 of the first and second thrust bearings 162.

When the surge generation condition is satisfied, the controller 700 may adjust the amount of current supplied to the thrust bearings 160 to position the rotation shaft 110 at the reference position C0 (S70). In detail, when the rotation shaft 110 is eccentrically leftward from the reference position C0, the controller 700 increases the amount of current supplied to the second thrust bearing 162, and the rotation shaft 110 changes the reference position ( When eccentrically from C0), the amount of current supplied to the first thrust bearing 161 may be increased.

Although the above has been illustrated and described with respect to the preferred embodiments of the present invention, the present invention is not limited to the specific embodiments described above, but in the technical field to which the invention belongs without departing from the spirit of the invention claimed in the claims. Various modifications can be made by those skilled in the art, and these modifications should not be individually understood from the technical spirit or the prospect of the present invention.

100: compressor
110: rotating shaft 120: impeller 140: bearing
141: magnetic bearing 200: condenser
300: expansion valve 400: evaporator
500: air conditioning unit 600: cooling water unit

Claims (13)

One or more impellers for sucking the refrigerant in an axial direction and compressing the refrigerant in a centrifugal direction;
A rotating shaft to which the impeller and the motor for rotating the impeller are connected;
At least two thrust bearings for limiting the oscillation of the axis of rotation;
A gap sensor for sensing a distance from the rotating shaft; And
And a controller configured to determine a surge occurrence condition based on the information received from the gap sensor.
And the control unit adjusts the amount of current supplied to the thrust bearings when the surge generation condition is satisfied, so that the rotation axis is eccentrically positioned in the opposite direction of the impeller at a reference position. The method of claim 1,
The thrust bearing,
The first thrust bearing,
And a second thrust bearing positioned closer to the impeller than the first thrust bearing, wherein at least a portion of the rotational shaft is located between the first thrust bearings. The method of claim 2,
And the controller supplies a current only to the first thrust bearing of the first and second thrust bearings when the surge generation condition is satisfied. The method of claim 2,
And the controller controls the amount of current supplied to the first thrust bearing to be greater than the amount of current supplied to the second thrust bearing when the surge generation condition is satisfied. The method of claim 2,
The rotation axis is,
Further comprising a rotary shaft blade extending in the radial direction of the rotary shaft,
The rotary blade blade is located between the first thrust bearing and the second thrust bearing. The method of claim 1,
The gap sensor is a compressor for measuring the axial movement of the rotation axis. The method of claim 1,
And when the position of the rotating shaft measured by the gap sensor is out of a normal position range, the controller determines that the surge generation condition is caused. The method of claim 1,
And the control unit determines that the surge is not generated when the position of the rotating shaft measured by the gap sensor is located within a normal position range. The method of claim 8,
And the control unit equally adjusts the amount of current supplied to the first thrust bearing and the amount of current supplied to the second thrust bearing when the surge non-occurrence condition is satisfied. The method of claim 1,
And a plurality of magnetic bearings for rotatably supporting the rotating shaft in the air. (A) measuring a distance between the gap sensor and the rotating shaft;
(B) determining a surge generation condition based on a distance between the gap sensor and the rotation axis;
And (c) positioning the rotary shaft eccentrically in the opposite direction of the impeller at a reference position by adjusting the amount of current supplied to the thrust bearings when the surge generation condition is satisfied. The method of claim 11,
And (d) adjusting the amount of current supplied to the thrust bearings to position the rotational shaft at the reference position when the surge non-occurrence condition is satisfied. The method of claim 11,
Step (c) is a control method of the compressor to control the amount of current supplied to the thrust bearing located relatively far from the impeller of the two thrust bearings than the amount of current supplied to the thrust bearing located close to the impeller .

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