KR20210121400A - Chiller - Google Patents

Abstract

The present invention relates to a chiller. A chiller according to an embodiment of the present invention includes a compressor for compressing and discharging refrigerant, a condenser for heat exchange between refrigerant discharged from the compressor and cooling water, an evaporator for heat exchange between refrigerant discharged from the condenser and cold water, and refrigerant discharged from the compressor One or more impellers and an evaporator that includes an ejector for mixing and discharging a part and a part of the refrigerant discharged from the evaporator, the compressor is connected to the rotating shaft, sucks the refrigerant in the axial direction according to the rotation of the rotating shaft and compresses the refrigerant in the centrifugal direction Mixing the refrigerant discharged from the and the refrigerant discharged from the ejector, may include a housing for guiding to the impeller. In addition, various embodiments are possible.

Description

chiller {CHILLER}

The present invention relates to a chiller, and more particularly, to a chiller capable of preventing a surge phenomenon of a compressor.

An air conditioner is a device for discharging cold and hot air into a room to create a comfortable indoor environment, and is installed to provide a more comfortable indoor environment to humans by controlling the indoor temperature and purifying the indoor air.

On the other hand, among air conditioners, chillers used in businesses or buildings larger than homes, as in Prior Document 1 (Korea Patent Publication No. 10-1084477), supply cold water to cold water consumers, and circulate the refrigeration system. It is characterized in that heat exchange is made between the refrigerant and the cold water circulating between the cold water demander and the refrigeration system to cool the cold water.

A general chiller includes a compressor that compresses and discharges a refrigerant, and the compressor may include one or more impellers rotating by a driving force of a driving motor to compress the refrigerant, a diffuser, and a housing in which the impeller is accommodated.

When such a compressor performs an operation outside the rated conditions prescribed by the pre-designed flow rate and compression ratio, a decrease in compression efficiency, stall, surge, choke, and the like may occur. In particular, the surge occurs when the compression ratio of the compressor is high compared to the flow rate of the refrigerant, and the rotating body of the compressor rotates idly, which means a phenomenon in which the flow of the refrigerant becomes irregular. As a result, severe vibration and noise may occur, which causes frequent damage to the compressor.

Conventionally, in order to prevent a surge of the compressor, as in Prior Document 2 (Korean Patent Application Laid-Open No. 10-2011-0109090), the compressor is provided with an inlet guide vane (IGV), and A method of controlling the opening is used. However, in the method of adjusting the opening degree of the suction guide vane (IGV), a driving device including a motor, a cam, a link, a gear, etc. must be separately provided in order to control the opening degree of the suction guide vane, so that the structure of the compressor becomes complicated. , the disadvantage is that the cost increases.

KR 10-1084477 B KR 10-2011-0109090 A

SUMMARY OF THE INVENTION The present invention aims to solve the above and other problems.

In addition, an object of the present invention is to provide a chiller provided with a device replacing the role of the suction guide vane for preventing a surge phenomenon during low-load operation.

Another object of the present invention is to provide a chiller capable of minimizing flow loss and noise when partially recovering a refrigerant in a compressor for low-load operation.

Another object of the present invention is to provide a chiller capable of further improving compression efficiency while preventing a surge phenomenon during low-load operation.

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

To achieve the above object, a chiller according to an embodiment of the present invention includes a compressor for compressing and discharging refrigerant, a condenser for exchanging heat between the refrigerant discharged from the compressor and cooling water, and an evaporator for exchanging heat between the refrigerant discharged from the condenser and cold water. and an ejector for mixing and discharging a portion of the refrigerant discharged from the compressor and a portion of the refrigerant discharged from the evaporator, wherein the compressor is connected to the rotating shaft and sucks the refrigerant in the axial direction according to the rotation of the rotating shaft in a centrifugal direction It may include a housing for guiding to the impeller by mixing the refrigerant discharged from the ejector and one or more impellers for compression and the refrigerant discharged from the evaporator.

In addition, the ejector includes a first inlet through which a portion of the refrigerant discharged from the compressor flows, and a second inlet through which a portion of the refrigerant discharged from the evaporator flows in, and the chiller is connected to a pipe connected to the first inlet. It may further include a valve for adjusting the flow rate of the refrigerant flowing into the first inlet.

In addition, the housing includes an inlet housing that forms a refrigerant inlet through which the refrigerant discharged from the evaporator is introduced, and the inlet housing is formed on one side of the outer wall and the outer wall forming the exterior, the refrigerant discharged from the ejector The inlet of the mixed refrigerant introduced therein is spaced apart from the outer wall, and is formed on the inner wall and one side of the inner wall forming the mixed refrigerant flow path through which the refrigerant introduced through the mixed refrigerant inlet flows, and the inner space of the mixed refrigerant flow path and the inlet housing It may include at least one mixed refrigerant outlet opening to be connected.

In addition, the mixed refrigerant outlet may be formed such that the refrigerant flowing through the mixed refrigerant flow path in a second direction different from the first direction in which the refrigerant discharged from the evaporator flows into the inner space of the inlet housing is discharged into the inner space of the inlet housing. can

In addition, a plurality of the mixed refrigerant outlets may be formed symmetrically with respect to the center of the inner space of the inlet housing.

In addition, the housing may further include a swirl housing formed by extending from the rear end of the inlet housing toward the impeller so that the inner diameter becomes smaller.

In addition, the housing may further include a channel housing extending in a radial direction from the rear end of the swirl housing and forming a channel for guiding the flow of the refrigerant passing through the impeller.

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

According to various embodiments of the present invention, by the vortex flow generated by the refrigerant flowing into the compressor due to the structural features of the housing forming the refrigerant suction port of the compressor, it is possible to prevent the occurrence of a surge phenomenon even during low-load operation. , it is possible to improve the operation reliability of the chiller.

In addition, according to various embodiments of the present invention, since the suction guide vane (IGV) and the driving device for adjusting the opening degree of the suction guide vane (IGV) are unnecessary, the price competitiveness of the product can be improved, and the internal structure of the compressor can be simplified.

In addition, according to various embodiments of the present invention, by further comprising an ejector for mixing the high-pressure refrigerant and the low-pressure refrigerant, the efficiency of the refrigeration system of the chiller can be increased compared to the case of generating a swirling flow of the refrigerant using only the high-pressure refrigerant. have.

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

1 is a view showing a chiller according to an embodiment of the present invention.
FIG. 2 is a schematic diagram of the chiller of FIG. 1 .
3 is a diagram schematically illustrating an internal structure of the ejector of FIG. 2 .
4 is an example of a perspective view of a compressor according to an embodiment of the present invention.
5 to 7 are diagrams referred to in the description of the configuration of the compressor of FIG. 4 .
8 is a diagram illustrating a flow of a refrigerant flowing along a mixed refrigerant passage of an inflow housing according to an embodiment of the present invention.

Advantages and features of the present invention and methods of achieving them will become 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 implemented in various different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the art to which the present invention pertains It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.

Spatially relative terms "below", "beneath", "lower", "above", "upper", etc. It can be used to easily describe the correlation between a component of , and another component. Spatially relative terms should be understood as terms including different orientations of components in use or operation in addition to the orientation shown in the drawings. For example, when a component shown in the drawing is turned over, a component described as “beneath” or “beneath” of another component may be placed “above” of the other component. can Accordingly, the exemplary term “below” may include both directions below and above. Components may also be oriented in other orientations, and thus spatially relative terms may be interpreted according to orientation.

The terminology used herein is for the purpose of describing the embodiments and is not intended to limit the present invention. As used herein, the singular also includes the plural unless specifically stated otherwise in the phrase. As used herein, "comprises" and/or "comprising" means that a referenced component, step and/or action excludes the presence or addition of one or more other components, steps and/or actions. I never do that.

Unless otherwise defined, all terms (including technical and scientific terms) used herein may be used with the meaning commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in a commonly used dictionary are not to be interpreted ideally or excessively unless clearly specifically defined.

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 do not fully reflect the actual size or area.

The suffixes "module" and "~ part" for the components used in the following description are given or mixed in consideration of only the ease of writing the specification, and do not have a meaning or role distinct from each other by themselves.

Also, in this specification, terms such as first and second may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another.

1 is a view showing a chiller according to an embodiment of the present invention.

Referring to FIG. 1 , the chiller 10 may include a compressor 100 , a condenser 200 , an expander 300 , and/or an evaporator 400 . In addition, the chiller 10 according to an embodiment of the present invention may further include a cooling water unit 600 and/or an air conditioning unit 500 .

The compressor 100 includes at least one impeller 120 that sucks the refrigerant in the axial direction and compresses it in the centrifugal direction, the rotating shaft 110 connected to the impeller 120, the rotor 112 and the stator 130, A bearing unit 140 including a motor rotating the rotating shaft 110, a plurality of magnetic bearings 141 supporting the rotating shaft 110 to be rotatable in the air, and a bearing housing 142 supporting the magnetic bearing 141) and/or a thrust bearing 160 to limit axial vibration of the rotation shaft 110 . The compressor 100 may further include at least one gap sensor (not shown) for detecting a distance from the rotating shaft 110 or a distance from the rotating shaft wing 111 . Here, the axial direction may mean a left-right direction in FIG. 1 .

The impeller 120 may rotate according to the rotation of the rotating shaft 110 , and through rotation in the centrifugal direction, the refrigerant introduced in the axial direction may be compressed into a high-temperature, high-pressure gaseous refrigerant. The impeller 120 may be composed of one stage or two stages, and may be composed of three or more stages.

The motor may include a rotor 112 and a stator 130 , and may rotate the rotating shaft 110 .

The rotating shaft 110 may be connected to the impeller 120 , and the rotating shaft 110 may extend in an axial direction. The rotating shaft 110 may include metal so as to be movable by the magnetic force of the magnetic bearing 141 and the thrust bearing 160 .

In order to prevent axial vibration of the rotation shaft 110 , the thrust bearing 160 may be formed with a constant area in a plane perpendicular to the axial direction of the rotation shaft 110 . The rotary shaft 110 may further include a rotary shaft blade 111 that provides 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. The rotary shaft blade 111 may be formed to extend in a rotational radial direction of the rotary shaft 110 .

The magnetic bearing 141 and the thrust bearing 160 may include a coil (not shown), and may function like a magnet by a current flowing in the coil. For example, when a current flows through the coil of the magnetic bearing 141 , the rotation shaft 110 may rotate without friction while being levitated in the air.

A plurality of magnetic bearings 141 may be provided to surround the rotating shaft 110 with the rotating shaft 110 as a center, and the thrust bearing 160 is a rotating shaft blade provided extending in a rotational radial direction of the rotating shaft 110 . It may be provided to be adjacent to (111).

The condenser 200 may exchange heat between the high-temperature and high-pressure gas refrigerant compressed and discharged by the compressor 100 and the cooling water flowing in from the cooling water unit 600 . In this case, the high-temperature, high-pressure gas refrigerant may be condensed through heat exchange with the cooling water.

The condenser 200 may be configured as a shell-tube type heat exchanger. For example, the high-temperature, high-pressure gas refrigerant compressed in the compressor 100 may be introduced into the condensing space 230 corresponding to the internal space of the condenser 200 through the condenser connection passage 150 . In addition, a cooling water passage 210 through which cooling water flowing in from the cooling water unit 600 may flow may be disposed in the condensation space 230 .

The cooling water flow path 210 may include a cooling water inflow path 211 through which cooling water is introduced from the cooling water unit 600 , and a cooling water discharge path 212 through which the cooling water is discharged to the cooling water unit 600 . The cooling water flowing into the cooling water inlet flow path 211 exchanges heat with the refrigerant inside the condensing space 230 , and then passes through the cooling water connection flow path 240 provided at one end inside or outside the condenser 200 , and the cooling water discharge flow path 212 . ) can be introduced.

The cooling water unit 600 and the condenser 200 may be connected through the cooling water tube 220 . The cooling water tube 220 may be made of a material such as rubber to not only serve as a passage through which the cooling water flows between the cooling water unit 600 and the condenser 200 but also to prevent the cooling water from leaking to the outside.

The cooling water tube 220 may include 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 that has undergone heat exchange with air or liquid in the cooling water unit 600 may be introduced into the condenser 200 through the cooling water inlet tube 221 . The cooling water introduced into the condenser 200 passes through the cooling water inlet flow path 211, the cooling water connection flow path 240, and the cooling water discharge flow path 212 provided inside the condenser 200 in order to be inside the condenser 200. After heat exchange with the introduced refrigerant, the coolant may be introduced into the coolant unit 600 through the coolant discharge tube 222 again.

The cooling water unit 600 includes the main body 630 , the cooling water inlet pipe 610 , which is an inlet through which the cooling water that has absorbed heat through the cooling water discharge tube 222 , is introduced, and after being cooled inside the cooling water unit 600 . It may include a cooling water discharge pipe 620 which is an outlet through which the cooling water is discharged.

Meanwhile, the cooling water unit 600 may air-cool the cooling water that has absorbed heat of the refrigerant through heat exchange in the condenser 200 in the main body 630 . For example, a fan (not shown) may be disposed in the main body 630 , and the coolant introduced into the main body 630 may be cooled according to a flow of air generated by the rotation of the fan.

The main body 630 may include a fan generating a flow of air, an air outlet 631 through which air is discharged, and/or an air inlet 632 corresponding to an inlet through which air is introduced into the body portion 630 . can Air discharged after heat exchange at the air outlet 631 may be used for heating.

The refrigerant that has undergone heat exchange in the condenser 200 may be condensed and accumulated in the lower portion of the condensing space 230 , and the refrigerant accumulated in the lower portion of the condensing space 230 may be introduced into the refrigerant box 250 provided in the condensing space 230 . After that, it may flow to the inflator 300 . For example, the refrigerant introduced into the refrigerant box 250 through the refrigerant inlet 251 may be discharged to the expander 300 through the evaporator connection passage 260 . The evaporator connection passage 260 includes an evaporator connection passage inlet 261 , and the evaporator connection passage inlet 261 may be located below the refrigerant box 250 .

The evaporator 400 may include an evaporation space 430 in which heat exchange occurs between the refrigerant expanded in the expander 300 and the cold water. For example, the refrigerant passing through the expander 300 may flow to the refrigerant injection device 450 provided in the evaporator 400 , and through the refrigerant injection hole 451 provided in the refrigerant injection device 450 . It may be sprayed into the evaporator 400 .

Inside the evaporator 400, a cold water flow path 410 including a cold water inflow path 411 through which cold water flows into the evaporator 400 and a cold water discharge path 412 through which cold water is discharged to the outside of the evaporator 400 is provided. can be placed.

The cold water may be introduced or discharged through the cold water tube 420 connected to the air conditioning unit 500 provided outside the evaporator 400 . The cold water tube 420 includes a cold water inlet tube 421 that is a passage for the cold water inside the air conditioning unit 500 to the evaporator 400 , and the cold water that has undergone heat exchange in the evaporator 400 into the air conditioning unit 500 . It may include a cold water discharge tube 422 that is a passage toward. That is, the cold water inlet tube 421 may be connected to the cold water inlet passage 411 , and the cold water discharge tube 422 may be connected to the cold water discharge passage 412 .

Looking at the flow of cold water, cold water is discharged from the air conditioning unit 500, passes through the cold water inlet tube 421 and the cold water inflow passage 411, and is provided at the inner end of the evaporator 400 or outside the evaporator 400 After passing through the cold water connection passage 440 , the cold water may be introduced back into the air conditioning unit 500 through the cold water discharge passage 412 and the cold water discharge tube 422 .

The cold water cooled by the refrigerant in the evaporator 400 may absorb heat from the air through heat exchange in the air conditioning unit 500 , and the air cooled by the cold water may be discharged into the room.

The air conditioning unit 500 may include a cold water discharge pipe 520 connected to the cold water inlet tube 421 and a cold water inlet pipe 510 connected to the cold water discharge tube 422 .

Meanwhile, the refrigerant after heat exchange in the evaporator 400 may be introduced back into the compressor 100 through the compressor connection passage 460 . In this case, the compressor connection passage 460 may be connected to the housing 170 of the compressor 100 that forms a refrigerant suction port through which the refrigerant is introduced.

FIG. 2 is a schematic diagram of the chiller of FIG. 1 .

Referring to FIG. 2 , the chiller 10 may include a compressor 100 , a condenser 200 , an expander 300 , an evaporator 400 , and/or an ejector 700 .

The compressor 100 may compress and discharge the refrigerant into a high-temperature, high-pressure gas refrigerant. At this time, at least a portion of the high-temperature and high-pressure gas refrigerant discharged from the compressor 100 may be transferred to the condenser 200 , and the remaining part of the high-temperature and high-pressure gas refrigerant that is not transferred to the condenser 200 is the ejector 700 . ) can be transferred.

The condenser 200 may exchange heat with cooling water with the high-temperature and high-pressure gas refrigerant discharged from the compressor 100 , and may discharge the refrigerant condensed by heat exchange to the expander 300 .

The expander 300 may expand the refrigerant condensed in the condenser 200 , and may deliver a low-temperature liquid refrigerant to the evaporator 400 .

The evaporator 400 may exchange heat with cold water and the low-temperature liquid refrigerant delivered from the expander 300 , and may discharge a low-pressure gas refrigerant through heat exchange. At this time, at least a portion of the low-pressure gas refrigerant discharged from the evaporator 400 may be transferred to the compressor 100 , and the remaining portion not transferred to the compressor 100 may be transferred to the ejector 700 .

The ejector 700 may include a first inlet 710 , a second inlet 720 , and an outlet 730 .

The chiller 10 may further include a valve 800 disposed on a pipe connected to the first inlet 710 of the ejector 700 to control the flow rate of the refrigerant flowing into the first inlet 710 . have. According to the degree of opening of the valve 800 , the flow rate of the high-temperature, high-pressure gas refrigerant supplied to the ejector 700 may be determined.

The ejector 700 may discharge a mixed refrigerant obtained by mixing a high-temperature, high-pressure gas refrigerant discharged from the compressor 100 and a low-pressure gas refrigerant discharged from the evaporator 400 . With respect to the ejector 700, it will be described with reference to FIG.

FIG. 3 is a diagram schematically illustrating an internal structure of the ejector of FIG. 2 .

Referring to FIG. 3 , the high-temperature, high-pressure gas refrigerant discharged from the compressor 100 may be introduced into the ejector 700 through the first inlet 710 and pass through the nozzle unit 741 at high speed. In this case, the flow rate of the refrigerant introduced through the first inlet 710 may increase while passing through the nozzle 741 , and the pressure may decrease. Meanwhile, some of the low-pressure gaseous refrigerant discharged from the evaporator 400 may be introduced into the second inlet 720 due to a pressure difference according to the pressure of the refrigerant lowered while passing through the nozzle unit 741 .

The refrigerant ejected through the nozzle unit 741 and the low-pressure gas refrigerant introduced through the second inlet unit 720 may be mixed in the mixing unit 742 , and the refrigerant ejected through the nozzle unit 741 may be The mixed refrigerant in which the refrigerant and the refrigerant introduced through the second inlet 720 are mixed passes through the diffuser unit 743 , the flow rate is lowered, the pressure is increased, and the refrigerant is discharged from the ejector 700 through the discharge unit 730 . can be ejected.

The mixed refrigerant discharged from the ejector 700 may be delivered to the compressor 100 . For example, the mixed refrigerant discharged from the ejector 700 may be supplied to the housing 170 forming the refrigerant inlet of the compressor 100 .

On the other hand, the chiller 10 is disposed on the pipe connected to the first inlet 710 of the ejector 700 and further includes a valve 800 for controlling the flow rate of the refrigerant flowing into the first inlet 710 . can do. The valve 800 may be an electronic expansion valve (EEV).

The housing 170 of the compressor 100 mixes the low-pressure gas refrigerant discharged from the evaporator 400 and the mixed refrigerant discharged from the ejector 700, and can be guided to the impeller 120 of the compressor 100. have. For a detailed description related to the compressor 100 , it will be described with reference to FIGS. 4 to 7 .

4 is an example of a perspective view of a compressor according to an embodiment of the present invention, FIG. 5 is an enlarged cross-sectional view taken along line A-A' of FIG. 4 , and FIG. 6 is an exploded view of some components of the compressor It is a perspective view in a closed state, and FIG. 7 is a perspective view of the housing.

4 to 7 , the compressor 100 may include a casing 102 forming an exterior of the compressor 100 and a housing 170 coupled to the casing 102 . For example, the casing 102 may extend rearwardly from the rear end of the housing 170 .

A discharge pipe coupler 152 to which the condenser connection passage 150 is coupled may be formed on one side of the casing 102 .

The refrigerant suction port 101 formed to be opened in the front and rear directions on the front surface of the housing 170 may be connected to the compressor connection passage 460 , and the low-pressure gas refrigerant flowing in the compressor connection passage 460 is transferred to the refrigerant suction port 101 . ) through the housing 170 may be supplied into the interior. The refrigerant outlet 151 through which the high-temperature, high-pressure gaseous refrigerant is discharged may be connected to the condenser connection passage 150 .

At one side of the casing 102 , a sub-refrigerant discharge port 153 through which some of the high-temperature and high-pressure gas refrigerant compressed in the compressor 100 is discharged may be disposed. For example, some of the high-temperature and high-pressure gaseous refrigerant may be supplied to the ejector 700 through a pipe connected to the sub-refrigerant outlet 153 . In this case, the valve 800 may be disposed in the pipe connected to the sub refrigerant outlet 153 .

A mixed refrigerant inlet 174 through which the mixed refrigerant discharged from the ejector 700 is introduced may be formed at one side of the housing 170 .

A motor may be disposed inside the casing 102 , and a rotation shaft 110 connected to the motor to transmit power may be located at the center.

A plurality of impellers 120a and 120b rotatably connected by a rotation shaft 110 may be disposed inside the casing 102 . The plurality of impellers 120a and 120b may be disposed at an end side of the rotating shaft 110 and a central portion of the rotating shaft 110 , respectively. For example, the first impeller 120a may be positioned toward the refrigerant inlet 101 , and the second impeller 120b may be positioned at the rear of the first impeller 120a. In this case, the first impeller 120a may be disposed to correspond to the center of the rear end of the housing 170 .

The first impeller 120a may be covered by the rear end of the housing 170 . Meanwhile, the second impeller 120b may be disposed at the center of the rear end of the diffuser 180 , and may be covered by the rear end of the diffuser 180 and the casing 102 .

A channel 190 for guiding the refrigerant compressed in the first impeller 120a to the second impeller 120b may be disposed on one side of the first impeller 120a. For example, the channel 190 may be formed outside the first impeller 120a in a radial direction.

The channel 190 may include a channel surface 191 recessed at the rear end of the housing 170 , front and rear surfaces of the return channel forming part 121 , and a front surface of the diffuser 180 .

형상의 유로를 형성할 수 있고, 채널(190)의 일측 단부는 제1 임펠러(120a)의 토출 측에 위치되며, 타측 단부는 제2 임펠러(120b)의 흡입 측에 위치될 수 있다.Here, the channel 190 composed of a space between the channel surface 191 and the front surface of the return channel forming unit 121 may be referred to as a first flow space or a first return channel. Also, a channel extending from the first return channel and configured by a space between the rear surface of the return channel forming unit 121 and the front surface of the diffuser 180 may be referred to as a second flow space or a second return channel. That is, the first return channel and the second return channel are formed on the outside of the first impeller 120a by the coupling structure.

A flow path may be formed, and one end of the channel 190 may be located on the discharge side of the first impeller 120a, and the other end may be located on the suction side of the second impeller 120b.

The refrigerant introduced through the refrigerant suction port 101 may be sucked into the suction side of the first impeller 120a and compressed in one stage, and may flow into the return channel. Meanwhile, the refrigerant compressed in one stage by the first impeller 120a may be sucked into the suction side of the second impeller 120b by the return channel and compressed in two stages. At this time, the refrigerant may be sucked into the space between the second impeller 120b and the diffuser 180 , and the refrigerant compressed in the second impeller 120b flows to the condenser connection passage 150 through the refrigerant outlet 151 . can do.

The return channel forming part 121 may be located rearwardly spaced apart from the rear surface of the housing 170 , and the rotation shaft 110 may be inserted into the center of the return channel forming part 121 . The front center of the return channel forming part 121 may support the rear surface of the first impeller 120a. The return channel forming part 121 may be formed in a disk shape having a diameter smaller than a diameter formed by the rear end of the channel housing 230 .

The return channel forming unit 121 may include a return channel vane 122 capable of guiding and compressing the refrigerant passing through the first impeller 120a. A plurality of return channel vanes 122 may be disposed along the circumferential direction on the front surface of the return channel forming unit 121 . The plurality of return channel vanes 122 may be spaced apart from each other in the circumferential direction, and may extend outwardly to form an arc or curve. For example, the plurality of return channel vanes 122 may extend in a radial direction to have a rake shape. The return channel vane 122 may protrude forward from the front surface of the return channel forming part 121 . In this case, the return channel vane 122 may be manufactured or formed integrally with the return channel forming part 121 .

The return channel forming unit 121 may further include a scroll guide 123 that protrudes backward from the rear surface and extends radially from the center. The scroll guide 123 may guide the refrigerant that has passed through the first return channel to the internal flow path 182 formed in the second impeller 120b or the diffuser 180 .

The diffuser 180 may be positioned so that the front side is in contact with the rear end of the scroll guide 123 . The diffuser 180 may be formed in the shape of a disk having a hollow formed therein.

The diffuser 180 may include an internal inlet 181 formed to bypass the first-stage compressed refrigerant flowing through the second return channel. A plurality of internal inlets 181 may be formed on the front surface of the diffuser 180 along the circumferential direction. The inner inlet 181 may be formed to penetrate the front surface of the diffuser 180 in the front-rear direction.

The diffuser 180 may be provided such that the rotating shaft 110 passes through the center, and the second impeller 120b is disposed at the rear center.

The diffuser 180 may include a plurality of diffuser vanes 187 protruding rearward from the rear surface along the circumferential direction. The diffuser vane 187 may be formed similarly to the return channel vane 122 . That is, the diffuser vane 187 may extend to have a rake shape along the radial direction, and may compress and guide the refrigerant passing through the second impeller 120b. At this time, the two-stage compressed refrigerant passing through the second impeller 120b and the diffuser vane 187 may flow to the refrigerant outlet 151 .

The diffuser 180 may further include an internal flow path 182 communicating with the internal inlet 181 . The internal flow path 182 may mean a space formed along the circumferential direction between the front and rear surfaces of the diffuser 180 . The internal flow path 182 may discharge the compressed refrigerant introduced through the internal inlet 181 to one side of the outer circumferential surface. That is, the diffuser 180 may further include an inner discharge port 183 that is opened to be radially open on one side of the outer circumferential surface. For example, the inner discharge port 183 may be formed such that one region of the circumferential surface of the diffuser 180 is opened.

The internal discharge port 183 may be connected to the internal flow path 182 and the sub refrigerant discharge port 153 . That is, the internal inlet 181 , the internal flow path 182 , and the internal discharge port 183 may be understood as a configuration formed to discharge the compressed refrigerant that has passed through the first return channel through the sub refrigerant outlet 153 .

In another embodiment, the inner inlet 181 may be formed on the rear surface of the diffuser 180 . In this case, the refrigerant discharged through the sub refrigerant outlet 153 may be a two-stage compressed refrigerant that has passed through the second impeller 120b.

In another embodiment, a hole connected to the sub refrigerant outlet 153 may be formed in the refrigerant outlet 151 , and an opening/closing device (not shown) may be installed in the hole. At this time, the refrigerant compressed in the first stage or the refrigerant compressed in the second stage may be selectively discharged through the sub refrigerant outlet 153 . Therefore, there is an advantage in that the refrigerant that has passed through the first impeller or the second impeller 120b can be selectively discharged in order to prevent a surge.

Meanwhile, the housing 170 may be coupled to the front of the casing 102 , and may be disposed to shield the front of the first impeller cover 121 .

The housing 170 may include a mixed refrigerant flow path 215 that guides the refrigerant introduced through the mixed refrigerant inlet 174 to flow along the outer circumference of the inner circumferential surface. Here, the inner circumferential surface of the housing 170 may mean an inner space extending rearward from the refrigerant suction port 101 .

The mixed refrigerant flow path 215 may be formed such that the refrigerant flowing in through the mixed refrigerant inlet 174 is branched and discharged into the inner space of the housing 170 . That is, the refrigerant introduced through the mixed refrigerant inlet 174 may be discharged into the inner space of the housing 170 at different points, respectively.

In this case, the point at which the refrigerant flowing through the mixed refrigerant flow path 215 is discharged into the inner space of the housing 170 may be a position at which the refrigerant flow in a swirl or vortex shape is generated in the inner space.

The housing 170 may form a plurality of mixed refrigerant outlets 179 so that the refrigerant is discharged at points symmetrical to each other with respect to the center of the inner space. For example, the plurality of mixed refrigerant outlets 179 may be positioned so as to form origin symmetry in the flow plane with each other.

The housing 170 includes an inlet housing 171 that forms a refrigerant inlet 101 on the front surface, a swirl housing 172 extending from the rear end of the inlet housing 171 to the rear so that the inner diameter becomes smaller, and a radius from the rear end of the swirl housing. It may include a channel housing 173 extending to extend in the direction.

The inlet housing 171 may form an internal space extending rearward from the refrigerant inlet 101 . The inner space of the inlet housing 171 may be connected to the inner space of the swirl housing 172 and the channel housing 173 to be connected to the inlet side of the first impeller 120a.

The inlet housing 171 may include a mixed refrigerant inlet 174 . The mixed refrigerant inlet 174 may be formed on one side of the outer peripheral surface of the inlet housing 171 .

The inlet housing 171 may form a mixed refrigerant flow path 178 , and the mixed refrigerant inlet 174 may be formed as an inlet of the mixed refrigerant flow path 178 .

At least one mixed refrigerant outlet 179 through which the refrigerant flowing through the mixed refrigerant flow path 178 is discharged into the inner space may be formed on the inner circumferential surface of the inlet housing 171 . The mixed refrigerant outlet 179 may be formed so that the refrigerant flowing in through the mixed refrigerant inlet 174 and the refrigerant flowing into the refrigerant inlet 101 are mixed to form a vortex flow. That is, the direction in which the refrigerant flows into the inner space of the inlet housing 171 through the refrigerant inlet 101 and the direction in which the refrigerant flows into the inner space of the inlet housing 171 through the mixed refrigerant outlet 179 may be different from each other. have.

For example, the first mixed refrigerant outlet 179a may be formed on one lower side of the inner circumferential surface of the inlet housing 171 , and the second mixed refrigerant outlet 179b may be formed on the other upper side of the inner circumferential surface of the inlet housing 171 . can In this case, the opening direction of the first mixed refrigerant outlet 179a may not form a direction facing the opening direction of the second mixed refrigerant outlet 179b.

That is, in order to form a vortex flow, when the first mixed refrigerant outlet 179a is formed to discharge the refrigerant in a straight line on one side from the upper part of the inner space, the second mixed refrigerant outlet 179b is opposite at the lower part of the inner space It may be formed to discharge the refrigerant in a straight direction on the other side. In addition, imaginary straight lines extending along the opening direction of the first mixed refrigerant outlet 179a and the second mixed refrigerant outlet 179b may be parallel.

Accordingly, the refrigerant discharged from the first mixed refrigerant outlet 179a and the refrigerant discharged through the second mixed refrigerant outlet 179b are discharged into the inner space of the inlet housing 171 and flow along the inner circumferential surface of the housing 170 . can do. In addition, the refrigerant flowing along the inner circumferential surface of the housing 170 may have a larger size of the rotation direction component of the speed toward the radial direction.

The swirl housing 172 may be formed to extend rearwardly from the rear end of the inlet housing 171 . The inner space formed by the inner circumferential surface of the swirl housing 172 may be understood as a space extending rearward from the inner space of the inflow housing 171 . In addition, the internal space of the swirl housing 172 may be formed so that the upstream (front) has a larger area than the downstream (rear).

The swirl housing 172 may be formed such that the inner diameter becomes smaller toward the rear. That is, the inner space of the housing 170 may extend from the refrigerant inlet 101 to the inlet of the first impeller 120a to have a smaller diameter. Accordingly, as the refrigerant having a relatively large rotational component flows in the axial direction (or rearward) discharged from the first mixed refrigerant outlet 179a and the second mixed refrigerant outlet 179b of the inlet housing 171, the flow cross-sectional area becomes smaller. Therefore, the magnitude of the velocity component in the rotational direction increases, so that the vortex flow can be effectively formed.

The channel housing 173 may be formed to extend radially from the rear end of the swirl housing 172 . A channel surface 191 forming the above-described channel 190 may be formed on a rear surface having an expanded diameter in the channel housing 173 . The channel face 191 forms a forward recessed face, which can extend along the circumferential direction. The first impeller 120a may be disposed at the center of the rear surface of the channel housing 173 .

Referring to FIG. 7 , the inflow housing 171 includes an outer wall 176 forming an outer surface or an outer circumferential surface, an inner space forming an inner space, and an inner wall 177 spaced inward from the outer wall 176 and extending in the circumferential direction. may include The inner wall 177 may extend in the circumferential direction to have a smaller diameter than the outer wall 176 .

The mixed refrigerant flow path 178 may refer to a space formed between the outer wall 176 and the inner wall 177 of the inlet housing 171 . For example, the mixed refrigerant flow path 178 may be formed by the inner surface of the outer wall 176 and the outer surface of the inner wall 177 .

A mixed refrigerant inlet 174 may be formed in the outer wall 176 , and the first mixed refrigerant flowing in the mixed refrigerant flow path 178 is discharged to the inner space of the inlet housing 171 in the inner wall 177 . A refrigerant outlet 179a and a second mixed refrigerant outlet 179b may be formed.

For example, the refrigerant introduced through the mixed refrigerant inlet 174 may flow between the outer wall 176 and the inner wall 177 along the mixed refrigerant flow path 178 , and the first mixed refrigerant outlet 179a and Through the second mixed refrigerant outlet 179b, it may be discharged into the inner space of the inlet housing 171 . At this time, the relatively low-temperature and low-pressure gas refrigerant introduced into the refrigerant inlet 101 is mixed with the refrigerant discharged through the first mixed refrigerant outlet 179a and the second mixed refrigerant outlet 179b, and has a rotating component. and can move.

The refrigerant discharged through the first mixed refrigerant outlet 179a and the second mixed refrigerant outlet 179b flows along the circular inner circumferential surface of the inlet housing 171, and flows in the axial direction (or rearward) while flowing in the swirl housing (172) can be passed.

The refrigerant passing through the swirl roughing 172 flows through the flow path in which the flow cross-sectional area is narrowed to the first impeller 120a located at the center of the channel housing 173, so that the vortex shape of the refrigerant is more easily and effectively generated. can

In addition, since the refrigerant guided to the first impeller 120a has a relatively large size of the speed component in the rotational direction, it is possible to improve the compression efficiency of the compressor 100 during a low load operation that reduces the total flow rate. That is, since the magnitude of the speed component in the axial direction of the refrigerant during low-load operation is small, the inflow direction, speed, etc. of the refrigerant flowing into the first impeller 120a has a higher resistance to the blade surface of the impeller than in the case of rated operation. It can be formed to be However, as in various embodiments of the present invention, when a swirling flow is formed by the refrigerant discharged through the first mixed refrigerant outlet 179a and the second mixed refrigerant outlet 179b, the component in the rotation direction increases, and the axis It can compensate for the reduced size of the velocity component of the direction component.

Accordingly, since the inflow direction and speed of the refrigerant flowing into the first impeller 120a is similar to that of the rated operation, flow resistance and flow loss can be minimized.

8 is a diagram illustrating a flow of a refrigerant flowing along a mixed refrigerant passage of an inflow housing according to an embodiment of the present invention.

Referring to FIG. 8 , the mixed refrigerant outlet 179 may be formed in a plurality of three or more. That is, the opening direction and number of the mixed refrigerant outlet 179 may be variously changed so that a swirling flow can be formed in the inner space of the housing 170 .

As described above, according to various embodiments of the present invention, by the swirl flow generated by the refrigerant flowing into the compressor 100 due to the structural features of the housing 170 forming the refrigerant suction port 101 of the compressor, It is possible to prevent the occurrence of a surge phenomenon even during load operation, thereby improving the operation reliability of the chiller 10 .

In addition, according to various embodiments of the present invention, since a driving device for adjusting the opening degree of the suction guide vane (IGV) and the suction guide vane (IGV) is unnecessary, the price competitiveness of the product can be improved, and the compressor (100) can simplify the internal structure of

In addition, according to various embodiments of the present invention, by further comprising an ejector 700 that mixes a high-pressure gas refrigerant and a low-pressure refrigerant, the chiller 10 ) can further increase the efficiency of the refrigeration system. That is, when some of the high-pressure refrigerant discharged from the compressor 100 is bypassed to the mixed refrigerant inlet 174 to generate a swirling flow of the refrigerant in the housing 170 , the flow rate of the refrigerant circulating in the refrigeration system is relatively less On the other hand, when the chiller 10 includes the ejector 700 , the low-pressure refrigerant discharged from the evaporator 400 after circulating the system flows into the mixed refrigerant inlet 174 together with the high-pressure refrigerant, so the refrigeration system Since the flow rate of the refrigerant circulating therein is relatively increased, the efficiency of the refrigeration system of the chiller 10 can be increased.

The accompanying drawings are only for easy understanding of the embodiments disclosed in the present specification, and the technical spirit disclosed herein is not limited by the accompanying drawings, and all changes and equivalents included in the spirit and scope of the present invention It should be understood to include water or substitutes.

In addition, although preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the specific embodiments described above, and the technical field to which the present invention belongs without departing from the gist of the present invention as claimed in the claims In addition, various modifications are possible by those of ordinary skill in the art, and these modifications should not be individually understood from the technical spirit or perspective of the present invention.

Claims (7)

a compressor for compressing and discharging the refrigerant;
a condenser for heat exchange between the refrigerant discharged from the compressor and the cooling water;
an evaporator for heat exchange between the refrigerant discharged from the condenser and the cold water; and
and an ejector mixing and discharging a portion of the refrigerant discharged from the compressor and a portion of the refrigerant discharged from the evaporator,
The compressor is
one or more impellers connected to the rotating shaft to suck the refrigerant in the axial direction and compress the refrigerant in the centrifugal direction according to the rotation of the rotating shaft; and
and a housing for mixing the refrigerant discharged from the evaporator and the refrigerant discharged from the ejector, and guiding the refrigerant to the impeller. According to claim 1,
The ejector includes a first inlet into which a portion of the refrigerant discharged from the compressor flows, and a second inlet through which a portion of the refrigerant discharged from the evaporator flows,
The chiller further comprising a valve disposed on a pipe connected to the first inlet to control a flow rate of the refrigerant flowing into the first inlet. 3. The method of claim 2,
The housing includes an inlet housing forming a refrigerant inlet through which the refrigerant discharged from the evaporator is introduced,
The inlet housing,
exterior walls that form a facade;
a mixed refrigerant inlet formed on one side of the outer wall and through which the refrigerant discharged from the ejector is introduced;
an inner wall spaced apart from the outer wall inward to form a mixed refrigerant flow path through which the refrigerant introduced through the mixed refrigerant inlet flows; and
and at least one mixed refrigerant discharge port formed on one side of the inner wall and opened to connect the mixed refrigerant flow path and the inner space of the inflow housing. 4. The method of claim 3,
The mixed refrigerant outlet is configured such that the refrigerant flowing through the mixed refrigerant flow path in a second direction different from the first direction in which the refrigerant discharged from the evaporator flows into the inner space of the inlet housing is discharged into the inner space of the inlet housing. Chiller, characterized in that formed. 5. The method of claim 4,
The chiller, characterized in that a plurality of the mixed refrigerant outlet is symmetrical with respect to the center of the inner space of the inlet housing. 6. The method of claim 5,
The housing, Chiller characterized in that it further comprises a swirl housing that is formed extending from the rear end of the inlet housing toward the impeller so that the inner diameter becomes smaller. 7. The method of claim 6,
The housing is
The chiller further comprises a channel housing extending in a radial direction from the rear end of the swirl housing and forming a channel for guiding the flow of the refrigerant passing through the impeller.

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