CN113324349B

CN113324349B - Radiator and refrigerating machine system

Info

Publication number: CN113324349B
Application number: CN202110218181.5A
Authority: CN
Inventors: 吴敬锡; 朴韩荣; 黄允济
Original assignee: LG Electronics Inc
Current assignee: LG Electronics Inc
Priority date: 2020-02-28
Filing date: 2021-02-26
Publication date: 2022-11-11
Anticipated expiration: 2041-02-26
Also published as: CN113324349A; KR102379341B1; KR20210110063A

Abstract

The present disclosure relates to heat sinks and chiller systems. A heat sink according to an embodiment of the present disclosure includes: a refrigerant pipe in which a refrigerant flows; a first heat discharging member contacting the refrigerant tube to exchange heat with the refrigerant tube; and a second heat dissipation member having at least one surface contacting the first heat dissipation member and having a surface exposed with respect to the one surface of the first heat dissipation member and contacting a heat source, wherein a material of the second heat dissipation member is different from a material of the first heat dissipation member, and a planar area of the second heat dissipation member is smaller than a planar area of the first heat dissipation member.

Description

Radiator and refrigerating machine system

Technical Field

The present disclosure relates to a heat sink.

Background

Generally, a chiller system supplies chilled water to a source of chilled water having a demand and provides cooling by heat exchange between refrigerant circulating in the chiller system and chilled water circulating between the demand source and the chiller system. As a cooling device of large capacity, a refrigerator system may be installed in a large building or the like.

In a chiller system, a controller and an inverter are installed to control the chiller system, particularly a compressor. In addition, when high heat is generated in the controller and the inverter, the refrigerator system further includes a radiator to dissipate the generated high heat.

However, the general radiator has a problem in that the inverter and the compressor may be overheated due to low heat radiation efficiency. Further, if a metal having high thermal conductivity is used in the heat sink, there arises a problem that production cost may be significantly increased.

Documents of the prior art

Patent literature

Korean laid-open patent publication No. 20110112908

Disclosure of Invention

An object of the present disclosure is to provide a heat sink capable of effectively dissipating heat generated in a controller and an inverter.

Another object of the present disclosure is to provide a heat sink that can easily couple a controller and an inverter and has excellent rigidity and heat dissipation efficiency.

It is still another object of the present disclosure to provide a heat sink having excellent heat dissipation efficiency and reduced production cost.

The object of the present disclosure is not limited to the foregoing object, and other objects not described herein will be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, the present disclosure provides a heat sink in which two heat dissipation members made of different materials are coupled to each other, and a heat source is in contact with the heat dissipation members having excellent heat dissipation efficiency.

In particular, according to an aspect of the present disclosure, the above and other objects can be accomplished by the provision of a heat sink comprising: a refrigerant pipe in which a refrigerant flows; a first heat discharging member contacting the refrigerant tube to exchange heat with the refrigerant tube; and a second heat dissipation member having at least one surface contacting the first heat dissipation member and having a surface exposed with respect to the one surface of the first heat dissipation member and contacting a heat source, wherein a material of the second heat dissipation member may be different from a material of the first heat dissipation member, and a planar area of the second heat dissipation member may be smaller than a planar area of the first heat dissipation member.

The first heat dissipation member may further include a receiving groove to receive at least a portion of the second heat dissipation member.

The depth of the receiving groove may be equal to the thickness of the second heat dissipation member.

The first heat dissipation member may further include a coupling groove disposed adjacent to the receiving groove and coupled with the coupling member.

The second heat dissipation member may include: a first contact surface exposed with respect to a top surface of the first heat dissipation member to contact the heat source; a second contact surface disposed opposite to the first contact surface and in contact with the first heat dissipation member; and a plurality of side contact surfaces having a smaller area than the first contact surface and the second contact surface and connecting the first contact surface and the second contact surface.

The plurality of side contact surfaces may be in contact with the first heat dissipation member.

The planar area of the second heat dissipation member may be 30% to 70% of the planar area of the first heat dissipation member.

The thickness of the second heat dissipation member may be less than the thickness of the first heat dissipation member.

The thickness of the second heat dissipation member may be 20% to 40% of the thickness of the first heat dissipation member.

The second heat dissipation member may have a higher thermal conductivity than the first heat dissipation member.

The second heat dissipation member may have a lower rigidity than the first heat dissipation member.

The material of the first heat dissipation member may include aluminum, and the material of the second heat dissipation member may include copper.

The first heat dissipation member may further include a plurality of heat dissipation fins formed on a surface opposite to a surface on which the second heat dissipation member is disposed.

In accordance with another aspect of the present disclosure, the above and other objects can be accomplished by the provision of a chiller system comprising: a housing forming an exterior; a heat source disposed within the housing; and a heat sink that radiates heat received from the heat source, wherein the heat sink may include: a refrigerant pipe in which a refrigerant flows; a first heat discharging member contacting the refrigerant tube to exchange heat with the refrigerant tube; and a second heat discharging member having at least one surface contacting the first heat discharging member and having a surface exposed to one surface of the first heat discharging member and contacting a heat source, wherein a material of the second heat discharging member may be different from a material of the first heat discharging member, and a planar area of the second heat discharging member may be smaller than a planar area of the first heat discharging member.

The heat source may include any one of a semiconductor device, an inverter, and a controller.

Additional details of exemplary embodiments are included in the detailed description and the accompanying drawings.

Effects of the invention

The heat sink according to the present disclosure has one or more of the following effects.

First, by using two heat dissipation members, both rigidity and heat dissipation efficiency of the heat sink can be improved.

Second, the maximum surface of the heat dissipation member, where the heat dissipation efficiency is high, is in contact with the controller or the inverter, so that excellent heat dissipation efficiency can be provided.

Third, by using two heat dissipation members made of aluminum and copper, the production cost can be reduced while maintaining the heat dissipation efficiency.

Fourth, the heat sink can rapidly dissipate heat, thereby preventing the refrigerator system from being damaged due to overheating.

The effects of the present disclosure are not limited to the above-described effects, and other effects not described herein will be clearly understood by those skilled in the art from the following description of the appended claims.

Drawings

Fig. 1 is a diagram illustrating a refrigerator system according to one embodiment of the present disclosure.

Fig. 2 is a diagram illustrating a structure of a compressor according to an embodiment of the present disclosure.

Fig. 3 is a block diagram illustrating a relationship between a controller and components connected thereto according to one embodiment of the present disclosure.

Fig. 4 is a diagram illustrating a normal operation condition of a compressor according to one embodiment of the present disclosure.

Fig. 5a is a diagram illustrating one example of surge avoidance operation in a compressor.

Fig. 5b is a diagram illustrating another example of surge avoidance operation in a compressor.

Fig. 6 is a diagram illustrating a case accommodating a heat sink according to an embodiment of the present disclosure.

Fig. 7a is a diagram illustrating a heat sink coupled with an inverter according to an embodiment of the present disclosure.

Fig. 7b is a side view of fig. 7 a.

Figure 7c is a plan view of a heat sink according to one embodiment of the present disclosure.

Fig. 7d is a cross-sectional view taken along line S11-S12 of fig. 7 c.

Fig. 8 is a cross-sectional view of a heat sink according to another embodiment of the present disclosure.

Detailed Description

Advantages and features of the present disclosure and methods of accomplishing the same will become more apparent from the following description of exemplary embodiments taken in conjunction with the accompanying drawings. However, the present disclosure is not limited to the following embodiments, but may be implemented in various different forms. These embodiments are provided merely for the complete disclosure of the present disclosure, and to provide those of ordinary skill in the art to which the present disclosure pertains, the category of the present disclosure being fully defined by the scope of the appended claims. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

Spatially relative terms, such as "below," "lower," "above," or "upper," may be used herein to describe one element's relationship to another element as illustrated. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in addition to the orientation depicted in the figures. For example, if the device in one of the figures is turned over, elements described as "below" or "beneath" other elements would then be oriented "above" the other elements. Thus, the exemplary terms "below" or "beneath" can encompass both an orientation of above and below. Because the device may be oriented in another direction, the spatially relative terms may be interpreted according to the orientation of the device.

The terminology used in the present disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used in this disclosure and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

In the drawings, the thickness or size of each constituent element is enlarged, omitted, or schematically illustrated for convenience of description and clarity. Moreover, the size or area of each constituent element does not completely reflect the actual size thereof.

Hereinafter, preferred embodiments of the present disclosure will be described with reference to the accompanying drawings.

Embodiments of the present disclosure will be described below with reference to the accompanying drawings to explain a compressor.

Fig. 1 is a chiller system including a compressor 100 of the present disclosure. The compressor 100 according to one embodiment of the present disclosure may be used not only as part of a chiller system, but also included in air conditioners and any other device as long as the device can compress gaseous materials.

Referring to fig. 1, a refrigerator system 1 according to an embodiment of the present disclosure includes: a compressor 100 configured to compress a refrigerant; a condenser 200 configured to condense refrigerant compressed by the compressor 100 through heat exchange between the refrigerant and a coolant; an expander 300 configured to expand the refrigerant condensed by the condenser 200; an evaporator 400 configured to cool the refrigerant water while evaporating the refrigerant through heat exchange between the refrigerant expanded by the expander 300 and the refrigerant water.

In addition, the refrigerator system 1 according to an embodiment of the present disclosure may further include: a coolant unit 600 configured to heat the coolant by heat exchange between the compressed refrigerant and the coolant at the condenser 200; and an air conditioning unit 500 configured to cool the cooling water by heat exchange between the expanded refrigerant and the cooling water at the evaporator 400.

The condenser 200 provides a space for heat exchange between a high-pressure refrigerant compressed by the compressor 100 and a coolant introduced from the coolant unit 600. The high pressure refrigerant may be condensed by heat exchange with a coolant.

The condenser 200 may comprise a shell and tube heat exchanger. Specifically, the high-pressure refrigerant compressed by the compressor 100 may be introduced into the condensing space 230 corresponding to the inner space of the condenser 200 via the discharge passage 150. In addition, a coolant channel 210 is formed in the condensation space 230, and a coolant introduced from the coolant unit 600 may flow through the coolant channel 210.

The coolant channel 210 may include: a coolant inlet passage 211 into which coolant is introduced from the coolant unit 600 into the coolant inlet passage 211; and a coolant discharge passage 212 through which the coolant is discharged to the coolant unit 600. The coolant introduced into the coolant inlet passage 211 may be heat-exchanged with the refrigerant inside the condensation space 230 and then may pass through a coolant connection passage 240 formed at one end inside the condenser 200 or formed at the outside thereof to be introduced into the coolant discharge passage 212.

The coolant unit 600 and the condenser 200 may be connected to each other via a coolant pipe 220. The coolant pipe 220 may serve as a coolant flow path between the coolant unit 600 and the condenser 200, and may be made of a rubber material or the like to prevent the coolant from leaking to the outside.

The coolant pipe 220 includes: a coolant inlet pipe 221 connected to the coolant inlet passage 211; and a coolant discharge pipe 222 connected to the coolant discharge passage 212. As for the total coolant flow, after heat-exchanging with air or liquid at the coolant unit 600, the coolant is introduced into the condenser 200 via the coolant inlet pipe 221. The coolant introduced into the condenser 200 passes through the coolant inlet passage 211, the coolant connection passage 240, and the coolant discharge passage 212 provided in the condenser 200 in order to exchange heat with the refrigerant introduced into the condenser 200, and then flows into the coolant unit 600 through the coolant discharge pipe 222 again.

The coolant absorbing heat from the refrigerant at the condenser 200 through heat exchange may be air-cooled by the coolant unit 600. The coolant unit 600 includes: a main body 630; a coolant inlet pipe 610 serving as an inlet for introducing the coolant that has absorbed heat; and a coolant discharge pipe 620 serving as a discharge outlet after the coolant is cooled in the coolant unit 600.

The coolant unit 600 may cool the coolant introduced into the main body 630 by using air. Specifically, the main body 630 has a fan generating an air flow, an air outlet 631 through which air is discharged, and an air inlet 632 through which air flows into the main body 630.

After the heat exchange, the air is discharged for heating through the air outlet 631. The refrigerant condensed after heat exchange at the condenser 200 stagnates at the lower portion of the condensing space 230. The stagnated refrigerant is fed into the refrigerant tank 250 provided in the condensation space 230 to flow into the expander 300.

The refrigerant tank 250 is introduced into the refrigerant inlet 251, and the introduced refrigerant may be discharged to the evaporator connecting passage 260. The evaporator connecting passage 260 has an evaporator connecting passage inlet 261 that may be disposed below the refrigerant tank 250.

The evaporator 400 may include an evaporation space 430, in which heat exchange is performed between the refrigerant expanded by the expander 300 and the cooling water in the evaporation space 430. In the evaporator connecting passage 260, the refrigerant having passed through the expander 300 is connected to the refrigerant injection device 450 provided in the evaporator 400, and passes through the refrigerant injection holes 451 to be uniformly dispersed in the evaporator 400.

Further, in the evaporator 400, a cold water passage 410 is provided, the cold water passage 410 including: a cold water inlet passage 411 through which cold water flows into the evaporator 400; and a cold water discharge passage 412 through which the cold water is discharged to the outside of the evaporator 400.

Cold water may be introduced or discharged through the cold water pipe 420 communicating with the air conditioning unit 500 disposed outside the evaporator 400. The cold water pipe 420 includes: a cold water inlet pipe 421 serving as a passage through which cold water in the air conditioning unit 500 flows toward the evaporator 400; and a cold water discharge pipe 422 serving as a passage through which cold water flows toward the air conditioning unit 500 after heat exchange at the evaporator 400. That is, the cold water inlet pipe 421 communicates with the cold water inlet passage 411, and the cold water discharge pipe 422 communicates with the cold water discharge passage 412.

As for the cold water flow, after passing through the air conditioning unit 500, the cold water inlet pipe 421 and the cold water inlet passage 411, the cold water passes through the cold water connection passage 440 provided at one end inside the evaporator 400 or provided at the outside thereof, and then flows into the air conditioning unit 500 again via the cold water discharge passage 412 and the cold water discharge pipe 422.

The air conditioning unit 500 cools cold water using a refrigerant. The cooled cold water may absorb heat of air in the air conditioning unit 500 to cool the indoor space. The air conditioning unit 500 may include: a cold water discharge pipe 520 communicating with the cold water inlet pipe 421; and a cold water inlet pipe 510 communicating with the cold water discharge pipe 422. After heat exchange at the evaporator 400, the refrigerant may again flow into the compressor 100 via the connection passage 460 of the compressor 100.

The portion of the refrigerant that has passed through the condenser 200 and the expander 300 flows into the refrigerant pipe of the radiator. In this embodiment, the heat sink includes: a heat radiating refrigerant supply pipe 11 guiding the refrigerant having passed through the expander 300 to the refrigerant pipe and supplying the refrigerant having passed through the refrigerant pipe to the evaporator 400; and a heat dissipation refrigerant discharge pipe 12.

The heat dissipation refrigerant supply pipe 11 connects one end of the refrigerant pipe and the evaporation pipe 453. The evaporation pipe 453 is a pipe connecting an input end of the evaporator 400 and the expander 300. The heat dissipation refrigerant discharge pipe 12 connects the other end of the refrigerant pipe and the evaporation pipe 453. The portion of the refrigerant flowing through the evaporation tube 453 flows toward the refrigerant tube via the heat-radiating refrigerant supply tube 11, and the refrigerant heat-exchanged in the refrigerant tube flows into the evaporation tube 453 via the heat-radiating refrigerant discharge tube 12.

Fig. 2 is a diagram illustrating a compressor 100 (also referred to as a turbo compressor) according to an embodiment of the present disclosure.

The compressor 100 illustrated in fig. 2 includes: one or more impellers 120 for drawing refrigerant in an axial direction Ax and compressing refrigerant in a centrifugal direction; a rotating shaft 110, an impeller 120, and a motor 130 rotating the impeller 120 are coupled to the rotating shaft 110; a bearing part 140 having a plurality of magnetic bearings 141 supporting the rotation shaft 110 such that the rotation shaft 110 can rotate in the air and a bearing housing 142 supporting the magnetic bearings 141; a vibration measuring sensor 72 that senses a distance from the rotation axis 110; and a thrust bearing 160 that restricts vibration of the rotating shaft 110 in the axial direction Ax. In addition, the compressor 100 of the present disclosure may further include a vibration measuring sensor 72 for measuring a vibration frequency of the discharge passage 150.

The impeller 120 may be a single stage or a two stage impeller in general, and a multi-stage impeller may be used. The impeller 120 may be rotated by the rotation shaft 110, and may compress the refrigerant introduced in the axial direction Ax into a high-pressure state by the rotation in the centrifugal direction.

The motor 130 has a rotation shaft 110 separated from the rotation shaft 110, and transmits torque to the rotation shaft 110 using a belt (not shown). However, in one embodiment of the present disclosure, the

motors

130 and 13 include a stator (not shown) and a rotor 112 that rotates the rotation shaft 110.

The rotating shaft 110 is coupled to the impeller 120 and the

motors

130 and 13. The rotation shaft 110 extends in the left-right direction of fig. 2. Hereinafter, the axial direction Ax of the rotating shaft 110 denotes the left-right direction. The rotating shaft 110 is desirably made of metal so that the rotating shaft 110 can be moved by the magnetic force of the magnetic bearing 141 and the thrust bearing 160.

In order to prevent the thrust bearing 160 from generating vibration in the axial direction Ax (left-right direction) of the rotating shaft 110, the rotating shaft 110 desirably has a predetermined area on a plane perpendicular to the axial direction Ax. Specifically, the rotation shaft 110 may further include wings 111, and the wings 111 provide a magnetic force sufficient to move the rotation shaft 110 using the magnetic force of the thrust bearing 160. The wings 111 of the rotating shaft 110 may have an area larger than a cross-sectional area of the rotating shaft 110 on a plane perpendicular to the axial direction Ax. The wings 111 of the rotating shaft 110 may extend in a radial direction of the rotating shaft 110.

The magnetic bearing 141 and the thrust bearing 160 are made of a conductive material, and the coil 143 is wound on the magnetic bearing 141 and the thrust bearing 160. The coil 143 serves as a magnet, and current flows through the wound coil 143.

A plurality of magnetic bearings 141 are arranged around the rotation shaft 110. The magnetic bearing 141 may support the rotation shaft 110 in a radial direction intersecting with an axial direction of the rotation shaft 110. The thrust bearing 160 is disposed adjacent to the wing 111 of the rotating shaft 110 extending in the direction of the rotational radius of the rotating shaft 110.

The magnetic bearing 141 allows the rotation shaft 110 to rotate without friction while floating in the air. For this, at least three magnetic bearings 141 should be disposed around the rotation shaft 110, and the respective magnetic bearings 141 should be in a balanced state with respect to the rotation shaft 110.

In one embodiment of the present disclosure, the four magnetic bearings 141 are symmetrical to each other with respect to the rotation shaft 110, and the rotation shaft 110 may float in the air by a magnetic force generated by coils wound on the respective magnetic bearings 141. Since the rotation shaft 110 rotates while floating in the air, energy loss due to friction can be reduced as compared with the related art using a general bearing.

The compressor 100 may also include a bearing housing 142 that supports the magnetic bearing 141. A plurality of magnetic bearings 141 may be provided, the plurality of magnetic bearings 141 being spaced apart with a gap therebetween so as not to contact the rotation shaft 110.

A plurality of magnetic bearings 141 are installed at least at two positions of the rotating shaft 110. These two positions are different positions in the longitudinal direction of the rotation axis 110. Since the rotating shaft 110 has a linear shape, it is necessary to support the rotating shaft 110 at least at two positions to prevent vibration in the circumferential direction.

As for the flow of the refrigerant, the refrigerant introduced into the compressor 100 through the connection passage 460 of the compressor 100 is compressed in the circumferential direction by the impeller 120 and then discharged through the discharge passage 150. The connection passage 460 of the compressor 100 is connected to the compressor 100 to allow refrigerant to be introduced in a direction perpendicular to the rotation direction of the impeller 120.

The thrust bearing 160 may limit movement due to vibration of the rotary shaft 110 in the axial direction Ax and may prevent the rotary shaft 110 from colliding with other components of the compressor 100 when the rotary shaft 110 moves toward the impeller 120 during surge.

Specifically, the thrust bearing 160 includes a first thrust bearing 161 and a second thrust bearing 162, and the first thrust bearing 161 and the second thrust bearing 162 are arranged around the wings 111 of the rotating shaft 110 in the axial direction Ax. That is, the first thrust bearing 161, the wings 111 of the rotating shaft 110, and the second thrust bearing 162 are arranged in this order in the axial direction Ax of the rotating shaft 110.

More specifically, the second thrust bearing 162 is disposed closer to the impeller 120 than the first thrust bearing 161, the first thrust bearing 161 is disposed farther from the impeller 120 than the second thrust bearing 162, and at least a portion of the rotary shaft 110 is disposed between the first thrust bearing 161 and the second thrust bearing 162. The wings 111 of the rotating shaft 110 are desirably disposed between the first thrust bearing 161 and the second thrust bearing 162.

Accordingly, the first thrust bearing 161 and the second thrust bearing 162 may provide an effect of minimizing vibration of the rotating shaft 110 in the direction of the rotating shaft 110 by the wings 111 of the rotating shaft 110 and the magnetic force.

The vibration measuring sensor 72 can measure the movement of the rotary shaft 110 in the axial direction Ax (left-right direction). The vibration measuring sensor 72 can also measure the movement of the rotating shaft 110 in the up-down direction (the direction perpendicular to the axial direction Ax). Further, the vibration measurement sensor 72 may include a plurality of vibration measurement sensors 72.

For example, the vibration measuring sensor 72 may include: a first gap sensor 710 measuring vertical movement of the rotation shaft 110; and a second gap sensor 720 measuring a horizontal movement of the rotation shaft 110. The second gap sensor 720 may be spaced apart from one end of the axial direction Ax of the rotary shaft 110 in the axial direction Ax.

The refrigerant compressed by the impeller 120 may be discharged through the discharge passage 150. The vibration measuring sensor 72 may measure a vibration frequency of the discharge passage 150, and may provide the vibration frequency value to the controller 700 or the memory 740. The vibration measuring sensor 72 may be disposed adjacent to the discharge passage 150. The vibration measuring sensor 72 may use an accelerometer or use various other methods to measure the vibration of the discharge passage 150.

When surge occurs, damage has been done to the compressor 100. Accordingly, the present disclosure provides a method of detecting the occurrence of surge events in the compressor 100 in advance before the occurrence of surge events and preventing surge at a stage before surge occurs.

By sensing the vibration frequency of the discharge passage 150, the measurement can be performed more efficiently than by sensing the vibration of the rotation shaft 110, thereby providing convenience in installing additional equipment.

Referring to fig. 3, in the present disclosure, a controller 700 may be further included, the controller 700 performing a surge avoidance operation based on the vibration frequency measured by the vibration measuring sensor 72.

The controller 700 may control a power amplifier 730, which power amplifier 730 amplifies the magnitude of the current applied to the vibration measuring sensor 72, the magnetic bearing 141, the motor 130, and the thrust bearing 160.

By controlling the power amplifier 730, the controller 700 may adjust the magnitude of the current applied to the magnetic bearing 141, the motor 130, and the thrust bearing 160; and the controller 700 may detect a position change of the rotary shaft 110 according to a current change by using the vibration measuring sensor 72.

The values measured by the vibration measuring sensor 72 are stored in the memory 740. Data such as the reference position C0, the normal position range (-C1 to + C1), the eccentric position, etc. may be stored in the memory 740 in advance. This data can be used for later surge occurrence condition determination, where the controller 700 can determine whether to perform a surge avoidance operation by comparing the values stored in the memory 740 with the measured values.

Specifically, upon determining that the vibration frequency falls outside of the normal vibration frequency range, the controller 700 may perform a surge avoidance operation.

Most surge events in the compressor 100 occur due to rotating stall caused by an increase in flow separation. The magnetic bearings control the position of the shaft so that the magnetic bearings can vibrate the shaft for a short period of time so as not to affect the system, while the controller 700 can operate while avoiding surge if the inverter product can manage flow separation before rotating stall occurs by controlling the RPM of the compressor 100.

The flow separation increases in a direction of closing the refrigerant flow passage, so that the increase of the flow separation can be detected based on a change in a vane passing frequency (BPF) value by analyzing a vibration component of the discharge passage 150. The present disclosure provides a method of avoiding surge by observing and controlling the growth of flow separation and removing flow separation. The BPF may be defined as a value obtained by multiplying the number of blade wings by the current operating frequency of the motor 130.

Here, the normal vibration frequency may be an experimentally determined value. In another example, if the vibration frequency of the discharge passage 150 is less than the BPF value, the controller 700 may determine that the vibration frequency falls outside the normal vibration frequency range. In yet another example, if the vibration frequency of the discharge passage 150, which is less than the BPF value, is maintained for a predetermined period of time, the controller 700 may determine that the vibration frequency falls outside the normal vibration frequency range.

The normal operation of the compressor 100 will be described below.

Fig. 4 is a diagram illustrating a normal operation condition of the compressor 100 according to one embodiment of the present disclosure.

Referring to fig. 4, during normal operation, the controller 700 maintains the operating frequency of the motor 130 at a normal frequency and controls the rotary shaft 110 to be located within a normal position range. Specifically, the controller 700 controls the magnetic bearing 141 to control the position of the rotary shaft 110 in the radial direction, and controls the thrust bearing 160 to control the position of the rotary shaft 110 in the axial direction Ax.

Hereinafter, an example of the surge avoiding operation in the compressor 100 will be described with reference to fig. 5 a.

Upon determining that the vibration frequency falls outside of the outer normal vibration frequency range, the controller 700 performs a surge avoidance operation.

For example, the surge avoiding operation is an operation of vibrating the rotary shaft 110 of the compressor 100 in the axial direction a predetermined number of times.

Upon determining that the vibration frequency falls outside the normal vibration frequency range, the controller 700 controls the two thrust bearings 160 to vibrate the rotary shaft 110 in the axial direction a predetermined number of times.

Specifically, upon determining that the vibration frequency falls outside the normal vibration frequency range, the controller 700 may change the current supplied to the first thrust bearing 161 and the current supplied to the second thrust bearing 162 a predetermined number of times.

Here, the current supplied to the first thrust bearing 161 and the current supplied to the second thrust bearing 162 may be randomly changed a predetermined number of times.

In order to vibrate the rotating shaft 110 in the axial direction at a predetermined frequency a predetermined number of times, the controller 700 may change the current supplied to the first thrust bearing 161 and the current supplied to the second thrust bearing 162 while detecting the position of the rotating shaft 110 in the axial direction based on the information received from the vibration measurement sensor 72.

More specifically, upon determining that the vibration frequency falls outside the normal vibration frequency range, the controller 700 may repeatedly perform the following operations a predetermined number of times: the first current value supplied to the first thrust bearing 161 is set to be smaller than the second current value supplied to the second thrust bearing 162, and then the first current value supplied to the first thrust bearing 161 is set to be larger than the second current value supplied to the second thrust bearing 162.

In this case, the operation range of the rotating shaft 110 may be set to a range smaller than the limit range, and the vibration may be generated within the normal position range (-C1 to + C1) or outside the normal position range (-C1 to + C1).

Hereinafter, another example of the surge avoiding operation in the compressor 100 will be described with reference to fig. 5b.

For example, the surge avoiding operation is an operation of vibrating the rotating shaft 110 of the compressor 100 in the radial direction a predetermined number of times.

Upon determining that the vibration frequency falls outside the normal vibration frequency range, the controller 700 controls the plurality of magnetic bearings 141 to vibrate the rotating shaft 110 in the radial direction a predetermined number of times.

Specifically, upon determining that the vibration frequency falls outside the normal vibration frequency range, the controller 700 may change the current supplied to the respective magnetic bearings 141a predetermined number of times.

Here, the currents supplied to the respective magnetic bearings 141 may be different from each other and may be randomly changed a predetermined number of times.

In order to vibrate the rotating shaft 110 in the radial direction at a predetermined frequency a predetermined number of times, the controller 700 may vary the current supplied to the respective magnetic bearings 141 while detecting the position of the rotating shaft 110 in the radial direction based on the information received from the vibration measuring sensor 72.

In the present disclosure, the plurality of magnetic bearings 141 are arranged in the circumferential direction; and based on fig. 5b, the magnetic bearing 141 disposed above the rotation shaft 110 may be defined as a first magnetic bearing 141a, and the magnetic bearing 141 disposed below the rotation shaft 110 may be defined as a second magnetic bearing 141b.

More specifically, upon determining that the vibration frequency falls outside the normal vibration frequency range, the controller 700 may repeatedly perform the following operations a predetermined number of times: the third current value supplied to the first magnetic bearing 141a is set to be smaller than the fourth current value supplied to the second magnetic bearing 141b, and then the third current value supplied to the first magnetic bearing 141a is set to be larger than the fourth current value supplied to the second magnetic bearing 141b.

In this case, the operating range of the rotating shaft 110 may be set to a range smaller than the limit range, and vibration may be generated within the normal position range (-Ax 1 to + Ax 1) or outside the normal position range (-Ax 1 to + Ax 1).

Fig. 6 is a diagram illustrating a case accommodating the heat sink 10 according to an embodiment of the present disclosure.

Referring to fig. 6, the heat sink 10 is accommodated in a case 1000. Specifically, the heat sink 10 may be accommodated in a machine room of the housing 1000. Here, the housing 1000 may accommodate the aforementioned compressor 100 and the controller 700 and the inverter.

The radiator 10 for cooling the controller 700 or the inverter will be described below.

Referring to fig. 7a to 7d, the heat sink 10 of the present disclosure includes a refrigerant pipe 16, a first heat discharging member 13, and a second heat discharging member 15. The heat sink 10 radiates heat of the heat source 14. The heat source 14 may include any one of a control unit, a controller, an inverter, a semiconductor device, and a heat generating component.

The first heat discharging member 13 is in contact with the refrigerant tube 16 to perform heat exchange with the refrigerant tube 16. The first heat dissipation member 13 provides an installation space of the second heat dissipation member 15. The second heat discharging member 15 may simply be in contact with the refrigerant tube 16 and may have a structure for receiving most of the refrigerant tube 16. The refrigerant pipe 16 may be embedded in the second heat discharging member 13. The first heat dissipation member 13 may have various shapes. For example, the first heat dissipation member 13 may have a rectangular shape.

The first heat dissipation member 13 may have a receiving groove 13d, and the receiving groove 13d receives at least a portion of the second heat dissipation member 15. There is no limitation on the shape and size of the receiving groove 13d, but if the receiving groove 13d is too deep, the second heat dissipation member 15 is difficult to contact the heat source 14, thereby reducing the heat dissipation performance; whereas, if the depth h3 of the receiving groove 13d is too shallow, the second heat dissipation member 15 protrudes upward from the first heat dissipation member 13, thereby increasing the thickness of the heat sink 10. Therefore, the depth h3 of the receiving groove 13d is desirably equal to the thickness h2 of the second heat dissipation member 15.

A receiving groove 13d may be formed in a downwardly recessed top surface of the first heat dissipation member 13. The top surface of the first heat dissipation member 13 may be a surface having the largest area among the surfaces of the first heat dissipation member 13.

A coupling groove 13a may be formed in the first heat dissipation member 13, the coupling groove 13a being disposed adjacent to the receiving groove 13d and coupled with the coupling member. The coupling groove 13a may be formed in the top surface of the first heat dissipation member 13.

Refrigerant flows in the refrigerant tubes 16. The low-temperature refrigerant having passed through the expander 300 flows through the refrigerant pipe 16 to cool the first heat discharging member 13. The refrigerant tubes 16 are arranged in a zigzag shape in the first heat dissipation member 13.

The second heat dissipation member 15 may enhance the thermal conductivity of the first heat dissipation member 13. The second heat discharging member 15 may have at least one surface contacting the first heat discharging member 13, and may have a surface exposed with respect to one surface of the first heat discharging member 13 and contacting the heat source 14.

Specifically, one surface of the second heat dissipation member 15 may be exposed, and the other surface of the second heat dissipation member 15 may be in contact with the first heat dissipation member 13. More specifically, the second heat dissipation member 15 may be received in the first heat dissipation member 13 with one surface exposed.

In particular, referring to fig. 7d, for example, the second heat discharging member 15 may include: a first contact surface 15a exposed with respect to the top surface of the first heat dissipation member 13 to be in contact with the heat source 14; a second contact surface 15b arranged opposite to the first contact surface 15a and in contact with the first heat dissipation member 13; and a plurality of side contact surfaces 15c having a smaller area than the first contact surface 15a and the second contact surface 15b and connecting the first contact surface 15a and the second contact surface 15b.

The first contact surface 15a has a larger area than the side contact surface 15 c. The first side contact surface 15c may have a shape corresponding to the planar shape of the heat source 14. The first side contact surface may have a square shape. Here, the planar shape is a shape when viewed from above, as shown in fig. 7 c.

The first contact surface 15a may be in surface contact with the heat source 14. The thermal pad may be disposed on the first contact surface 15 a. The second contact surface 15b may be in surface contact with the receiving groove 13d of the first heat dissipation member 13. The plurality of side contact surfaces 15c may be in surface contact with the receiving groove 13d of the first heat dissipation member 13.

The material of the first heat dissipation member 13 may include aluminum having excellent rigidity and heat dissipation efficiency. Aluminum having excellent rigidity can withstand the pressure of the refrigerant tube 16 and can maintain the structure, but has a disadvantage of low thermal conductivity.

Therefore, in order to improve thermal conductivity while maintaining structural rigidity, the second heat dissipation member 15 is made of a material different from that of the first heat dissipation member 13. Specifically, the thermal conductivity of the second heat dissipation member 15 may be higher than that of the first heat dissipation member 13. The rigidity of the second heat dissipation member 15 may be lower than that of the first heat dissipation member 13.

The second heat dissipation member 15 is desirably made of copper, which is low in production cost, high in thermal conductivity, and low in rigidity, as compared to the first heat dissipation member 13.

By providing the heat sink 10 with the heat dissipation member made of two materials, the heat dissipation efficiency of the heat sink 10 can be improved while maintaining the rigidity of the heat sink 10, reducing the production cost.

If the area occupied by the second heat dissipation member 15 is too large, the rigidity of the heat sink 10 is lowered, and if the area occupied by the second heat dissipation member 15 is too small, the heat dissipation efficiency of the heat sink 10 is lowered.

Therefore, the planar area of the second heat dissipation member 15 is desirably smaller than that of the first heat dissipation member 13. Here, the plane area refers to an area when viewed from above, as shown in fig. 7 c.

More desirably, the planar area of the second heat dissipation member 15 may be 30% to 70% of the planar area of the first heat dissipation member 13. If the planar area of the second heat dissipation member 15 exceeds 70% of the planar area of the first heat dissipation member 13, the rigidity of the heat sink 10 is reduced; and if the planar area of the second heat dissipation member 15 is less than 30% of the planar area of the first heat dissipation member 13, the heat dissipation efficiency is lowered.

If the thickness of the second heat dissipation member 15 is too large, the rigidity of the heat sink 10 is reduced, and the thickness of the heat sink 10 is increased. If the thickness of the second heat dissipation member 15 is too small, the second heat dissipation member 15 is difficult to contact the heat source 14, so that heat dissipation efficiency may be reduced.

Therefore, the thickness h2 of the second heat dissipation member 15 is desirably smaller than the thickness h1 of the first heat dissipation member 13.

More desirably, the thickness h2 of the second heat dissipation member 15 may be 20% to 40% of the thickness h1 of the first heat dissipation member 13. If the thickness h2 of the second heat dissipation member 15 exceeds 40% of the thickness h1 of the first heat dissipation member 13, the rigidity of the heat sink 10 is reduced; and if the thickness h2 of the second heat dissipation member 15 is less than 20% of the thickness h1 of the first heat dissipation member 13, the heat dissipation efficiency of the heat sink 10 is lowered.

As shown in fig. 8, the heat sink 10 according to the second embodiment of the present disclosure may further include heat dissipation fins 17, as compared to the embodiment of fig. 7a to 7 d. The following description of the heat sink 10 according to the second embodiment will focus on differences from the embodiment of fig. 7a to 7d, and details not specifically described herein are considered to be the same as those of fig. 7a to 7 d.

The heat dissipation fins 17 are formed on a surface opposite to the surface on which the second heat dissipation member 15 is arranged. Specifically, the heat dissipation fins 17 extend downward from the lower surface 13c of the first heat dissipation member 13.

The heat radiating fins 17 have the shape of elongated fins or plates. The thickness or width of the heat dissipation fins 17 is much smaller than the thickness h1 or width of the first heat dissipation member 13, thereby increasing the contact area with the air or the refrigerant. A plurality of heat radiating fins 17 may be provided.

Since the heat radiating fins 17 can increase the contact area with the air, the radiator 10 can be cooled by heat exchange with the refrigerant and the air.

While embodiments have been shown and described, it will be understood by those skilled in the art that various changes in these embodiments may be made without departing from the spirit and scope of the disclosure as defined by the appended claims. Accordingly, the scope of the present disclosure is not to be construed as limited to the described embodiments, but is defined by the appended claims and equivalents thereof.

Claims

1. A heat sink, comprising:

a refrigerant pipe in which a refrigerant flows;

a first heat dissipation member in contact with the refrigerant pipe to exchange heat with the refrigerant pipe; and

a second heat dissipation member having at least one surface in contact with the first heat dissipation member and having a surface exposed with respect to the one surface of the first heat dissipation member and in contact with a heat source,

wherein a material of the second heat dissipation member is different from a material of the first heat dissipation member, and a planar area of the second heat dissipation member is smaller than a planar area of the first heat dissipation member,

wherein a material of the first heat dissipation member includes aluminum, and a material of the second heat dissipation member includes copper,

wherein the first heat dissipation member further includes a receiving groove that receives at least a portion of the second heat dissipation member, and

wherein a depth of the receiving groove is equal to a thickness of the second heat dissipation member.

2. The heat sink of claim 1, wherein the first heat dissipation member further comprises a coupling groove disposed adjacent to the receiving groove and coupled with a coupling member.

3. The heat sink of claim 1, wherein the second heat dissipating member comprises:

a first contact surface exposed with respect to a top surface of the first heat dissipation member to contact the heat source;

a second contact surface disposed opposite to the first contact surface and in contact with the first heat dissipation member; and

a plurality of side contact surfaces having a smaller area than the first contact surface and the second contact surface and connecting the first contact surface and the second contact surface.

4. The heat sink of claim 3, wherein the plurality of side contact surfaces are in contact with the first heat dissipating member.

5. The heat sink of claim 1, wherein the planar area of the second heat dissipating member is 30% to 70% of the planar area of the first heat dissipating member.

6. The heat sink of claim 1, wherein a thickness of the second heat dissipating member is less than a thickness of the first heat dissipating member.

7. The heat sink of claim 1, wherein the thickness of the second heat dissipation member is 20% to 40% of the thickness of the first heat dissipation member.

8. The heat sink according to claim 1, wherein a thermal conductivity of the second heat dissipation member is higher than a thermal conductivity of the first heat dissipation member.

9. The heat sink according to claim 1, wherein the second heat dissipation member has a lower rigidity than the first heat dissipation member.

10. The heat sink according to claim 1, wherein the first heat dissipation member further comprises a plurality of heat dissipation fins formed on a surface opposite to a surface on which the second heat dissipation member is arranged.

11. A chiller system, the chiller system comprising:

a housing forming an exterior;

a heat source disposed within the housing; and

a heat sink that dissipates heat received from the heat source,

wherein, the radiator includes:

a refrigerant pipe in which a refrigerant flows;

a second heat dissipation member having at least one surface in contact with the first heat dissipation member and having a surface exposed with respect to one surface of the first heat dissipation member and in contact with a heat source,

12. The chiller system of claim 11, wherein the heat source comprises any of a semiconductor device, an inverter, and a controller.