Abstract:
Provided is an air conditioner. The air conditioner including a compressor for compressing a refrigerant, a condenser for condensing the refrigerant compressed by the compressor, a phase separator for separating a gaseous refrigerant from the refrigerant passing through the condenser, and an evaporator for evaporating the refrigerant passing through the phase separator includes an inflow part provided in the phase separator to introduce the refrigerant into the phase separator, a gas separation part configured to discharge the gaseous refrigerant separated by the phase separator, an injection passage configured to inject the refrigerant discharged from the phase separator into the compressor, and an internal heat-exchanger provided within the phase separator to heat-exchange a refrigerant therein with the refrigerant introduced through the inflow part.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims priority under 35 U.S.C. 119 and 35 U.S.C. 365 to Korean Patent Application No. 10-2001-0089982 filed on Sep. 6, 2001, which is hereby incorporated by reference in its entirety. 
       BACKGROUND 
       [0002]    The present disclosure relates to an air conditioner, and more particularly, to an air conditioner having improved system efficiency and performance and a compact size. 
         [0003]    Generally, an air conditioner is an appliance that cools and heats an indoor space by heat-exchanging between air and a refrigerant while the refrigerant is compressed, condensed, expanded, and evaporated. The air conditioner includes a compressor, a condenser, an expansion valve, and an evaporator. The refrigerant discharged from the compressor is condensed in the condenser and expanded in the expansion valve. The expanded refrigerant is evaporated in the evaporator and then is sucked again into the compressor. 
         [0004]    However, the air conditioner according to a related art may not sufficiently execute its cooling or heating performance when a cooling or heating load is varied according to variations of temperatures of indoor and outdoor spaces. For example, in case of an extreme cold area, since a temperature exchange with external air does not smoothly occur, the cooling performance may be significantly deteriorated. To solve this limitation, a compressor having large capacity should be provided or an additional compressor should be further provided. 
         [0005]    To solve the above-described limitation, a vapor injection method for reducing a load of the compressor and securing a sufficient refrigerant by introducing a portion of the refrigerant passing through the condenser again into the compressor when the cooling or heating load is increased has been proposed. 
         [0006]    Referring to  FIG. 1 , the air conditioner according to the related art includes a compressor  10  including a first compression part  12 , a second compression part  14 , and a third compression part  16 . 
         [0007]    A refrigerant discharged from the compressor  10  passes through a first expansion unit  30  via a condenser  20 . The refrigerant passing through the first expansion unit  30  inflows into a phase separator  40 . The refrigerant inflowing into the phase separator  40  is in a state in which a liquid refrigerant and a gaseous refrigerant are mixed with each other, and also is separated into the liquid refrigerant and the gaseous refrigerant by passing through the phase separator  40 . The phase separator  40  discharges the separated gaseous refrigerant into a separate tube. Also, the refrigerating in which the liquid refrigerant remaining after the gaseous refrigerant is separated and the gaseous refrigerant are mixed with each other are discharged through a separate outflow part. 
         [0008]    The separated gaseous refrigerant may flow toward a discharge part of the second compression part  14  of the compressor  10  through a first injection tube  45 . The refrigerant discharged from the second compression part  14  and the refrigerant introduced through the first injection tube  45  are mixed with each other to flow into the third compression part  16 . 
         [0009]    A first injection valve  42  is disposed in the first injection tube  45 . The first injection valve  42  may control the amount of refrigerant flowing into the first injection tube  45  according to a heating load of the air conditioner. 
         [0010]    The liquid and gaseous refrigerants discharged from the phase separator  40  flow into an internal heat-exchanger  50 . The air conditioner may further include a second injection tube branched from a tube connected to the internal heat-exchanger  50 . The refrigerant flowing into the second injection tube  65  may be heat-exchanged with the refrigerant discharged from the phase separator  40  while flowing into the internal heat-exchanger  50 . 
         [0011]    The second injection tube  65  is connected to the compressor  10 . In detail, the second injection tube  65  is connected to the discharge part of the first compression part  12 . Also, the refrigerant flowing into the second injection tube  65  is mixed with the refrigerant discharged from the first compression  12 , and then the mixed refrigerant flows into the second compression part  14 . 
         [0012]    The refrigerant discharged from the phase separator  40  is throttled while passing through a second expansion valve  70 , and the refrigerant passing through the second expansion valve  70  flows into an evaporator  80 . The refrigerant evaporated in the evaporator  80  is introduced again into the compressor  10  to form a heating cycle. 
         [0013]    As described above, in the air conditioner according to the related art, to inject the refrigerant into the compressor  10  including the plurality of compression parts, the phase separator  40  and the internal heat-exchanger should be separately provided. Thus, the air conditioner may be complicated in structure and increased in manufacturing cost. 
         [0014]    Although not shown, the phase separator  40  may be omitted and the internal heat-exchanger may be provided. In this case, the refrigerant may be injected into the compressor using two internal heat-exchangers. Similarly, in case where the two internal heat-exchangers are provided, the air conditioner may be complicated in structure and increased in manufacturing cost. 
       SUMMARY 
       [0015]    Embodiments provide an air conditioner which is capable of improving cooling or heating performance and efficiently utilizing an inner space. 
         [0016]    Embodiments also provide an air conditioner including an internal heat-exchanger and a phase separator which are capable of being utilized during the cooling or heating. 
         [0017]    In one embodiment, an air conditioner including a compressor for compressing a refrigerant, a condenser for condensing the refrigerant compressed by the compressor, a phase separator for separating a gaseous refrigerant from the refrigerant passing through the condenser, and an evaporator for evaporating the refrigerant passing through the phase separator includes: an inflow part provided in the phase separator to introduce the refrigerant into the phase separator; a gas separation part configured to discharge the gaseous refrigerant separated by the phase separator; an injection passage configured to inject the refrigerant discharged from the phase separator into the compressor; and an internal heat-exchanger provided within the phase separator to heat-exchange a refrigerant therein with the refrigerant introduced through the inflow part. 
         [0018]    In another embodiment, an air conditioner includes: a multi-stage compressible compressor; a phase separator for separating a gaseous refrigerant from a liquid refrigerant; a gas separation part configured to discharge the gaseous refrigerant separated by the phase separator, the gas separation part guiding injection of the refrigerant into the compressor; an inflow part configured to introduce the refrigerant into the phase separator; an outflow part configured to discharge the refrigerant introduced through the inflow part; a bypass part branched from the outflow part to guide the inflow of the refrigerant into the phase separator; and an internal heat-exchanger configured to heat-exchange the refrigerant stored in the phase separator with the refrigerant flowing into the bypass part. 
         [0019]    The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features will be apparent from the description and drawings, and from the claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]      FIG. 1  is a schematic view illustrating a refrigerant cycle of an air conditioner according to a related art. 
           [0021]      FIG. 2  is a view of a phase separator according to an embodiment. 
           [0022]      FIG. 3  is a view illustrating a connection relationship between a phase separator and a compressor according to an embodiment. 
           [0023]      FIG. 4  is a view illustrating a refrigerant flow during the heating in a refrigerant cycle in which a phase separator is applied according to an embodiment. 
           [0024]      FIG. 5  is a view illustrating a refrigerant flow during the cooling in a refrigerant cycle in which a phase separator is applied according to an embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0025]    Hereinafter, exemplary embodiments will be described with reference to the accompanying drawings. The invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein; rather, that alternate embodiments included in other retrogressive inventions or falling within the spirit and scope of the present disclosure will fully convey the concept of the invention to those skilled in the art. 
         [0026]    In the detailed description of the present application, a term an “inlet side” or “outlet side” may a term defined based on a flow direction of a refrigerant. 
         [0027]      FIG. 2  is a view of a phase separator according to an embodiment.  FIG. 3  is a view illustrating a connection relationship between a phase separator and a compressor according to an embodiment. 
         [0028]    Referring to  FIGS. 2 and 3 , an air conditioner according to an embodiment includes a compressor  200  and a phase separator  100  for discharging a refrigerant to be injected into the compressor  200 . 
         [0029]    In detail, the compressor  200  includes first, second, and third compression parts  202 ,  204 , and  206  to compress the refrigerant in multiple stages. Thus, the refrigerant flowing into the compressor  200  is compressed while successively passing through the first, second, and third compression parts  202 ,  204 , and  206 . After the refrigerant is compressed by the third compression part  206 , the refrigerant is discharged from the compressor  10 . 
         [0030]    The phase separator  100  includes an inflow part  110  through which a refrigerant expanded through a first expansion unit  210 , a gas separation part  130  through which a gaseous refrigerant separated from the refrigerant flowing into the inflow part  110  is discharged, and an outflow part  120  through which the refrigerant flowing into the inflow part  110  and remaining after the gaseous refrigerant is separated is discharged. 
         [0031]    The first expansion unit  210  decompresses the refrigerant condensed by a condenser. The refrigerant has a two-phase state, i.e., a state in which the liquid refrigerant and the gaseous refrigerant are mixed with each other when the refrigerant is decompressed by the first expansion unit  210 . 
         [0032]    The gaseous refrigerant of the refrigerant introduced through the inflow part  110  is discharged through the gas separation part  130 . To easily discharge the gaseous refrigerant, the gas separation part  130  extends upward from a top surface of the phase separator  100 . 
         [0033]    A high pressure injection passage  235  for guiding the gaseous refrigerant discharged from the gas separation part  130  to the compressor  200  is disposed between the gas separation part  130  and the compressor  200 . 
         [0034]    The high pressure injection passage  235  is connected to a discharge side of the second compression part  204 . The refrigerant flowing into the high pressure injection passage  235  is mixed with the refrigerant compressed by the second compression part  204  and flows into the third compression pat  206 . A portion of the compressor  200  connected to the high pressure injection passage  235  may be called a “high pressure part”. 
         [0035]    An injection valve  230  for adjusting the amount of refrigerant to be injected into the compressor  200  is disposed in the high pressure injection passage  235 . An opening degree of the injection valve  230  may be controlled based on the amount of refrigerant required according to the cooling or heating load. 
         [0036]    The refrigerant introduced through the inflow part  110  is cooled when the refrigerant is heat-exchanged in an internal heat-exchanger  145  and then discharged to the outside of the phase separator  100  through the outflow part  120 . 
         [0037]    A second expansion unit  220  for decompressing the refrigerant is disposed at the discharge side of the inflow part  120 . The refrigerant discharged through the inflow part  120  flows into an evaporator after the refrigerant is expanded by the second expansion unit  220 . 
         [0038]    The phase separator  100  includes a first inflow tube  140  through which at least one portion of the refrigerant discharged through the outflow part  120  is branched and flows and a first outflow tube  150  for guiding the refrigerant introduced through the first inflow tube  140  to the outside of the phase separator  100 . 
         [0039]    The first inflow tube  140  bypasses the refrigerant discharged from the phase separator  100  to flow again into the phase separator  100 . Thus, the first inflow tube  140  may be called a “bypass part”. Also, the first inflow tube  140  may extend inward from the outside of the phase separator  100 . 
         [0040]    A third expansion unit  240  for expanding the refrigerant is disposed in the first inflow tube  140 . The refrigerant bypassed into the first inflow tube  140  may be cooled while passing through the third expansion unit  240  and flow into the phase separator  100 . 
         [0041]    The internal heat-exchanger  145  communicating with the first inflow tube  140  and the first outflow tube  150  is disposed in an inner space of the phase separator  100 . The refrigerant introduced through the first inflow tube  140  flows into the first outflow tube  150  via the internal heat-exchanger  145 . 
         [0042]    The internal heat-exchanger  145  may have a structure which includes a tube through which a refrigerant flows and has a wide surface area to improve heat-exchange efficiency. For example, the internal heat-exchanger  145  may have a plurality of bent shapes such as a coil. 
         [0043]    The refrigerant (hereinafter, referred to as a first refrigerant) introduced through the inflow part  110  and the refrigerant (hereinafter, referred to as a second refrigerant) introduced through the first inflow tube  140  are heat-exchanged with each other in the internal heat-exchanger  145 . In detail, the refrigerant introduced through the inflow part  110  is disposed at the outside of the tube of the internal heat-exchanger  145  in a state where the refrigerant is stored in the phase separator  100 . Also, the refrigerant introduced through the first inflow tube  140  flows into the tube. Thus, the refrigerants may be heat-exchanged with each other. 
         [0044]    When the first and second refrigerants are heat-exchanged with each other, the second refrigerant absorbs heat. As a result, at least one portion of the second refrigerant may be phase-changed in a gaseous state. The phase-changed gaseous refrigerant is discharged to the outside of the phase separator  100  through the first outflow tube  150 . The first outflow tube  150  extends upward from the top surface of the phase separator  100 . 
         [0045]    A low pressure injection passage  250  for guiding the refrigerant discharged through the first outflow tube  150  to the compressor  200  is disposed between the phase separator  100  and the compressor  200 . The low pressure injection passage  250  is connected to a discharge side of the first compression part  202 . The refrigerant flowing into the compressor  200  through the low pressure injection passage  250  may be mixed with the refrigerant compressed by the first compression part  202  and flow into the second compression part  204 . 
         [0046]    A portion of the compressor  200  connected to the low pressure injection passage  250  may be called a “low pressure part”. The refrigerant flowing into the low pressure injection passage  250  may have a pressure less than that of the refrigerant flowing into the high pressure injection passage  235 . 
         [0047]    The amount of refrigerant injected through the low pressure injection passage  250  may be adjusted by controlling an opening degree of the third expansion unit  240 . The opening degree of the third expansion unit  240  may be adjusted based on the amount of refrigerant introduced through the inflow part  110  or a state of the refrigerant. 
         [0048]    That is, since the heat-exchanged amount or heat-exchange efficiency in the internal heat-exchanger  145  may be determined according to the amount (or the stored refrigerant amount) of refrigerant stored in the phase separator  100  or a state of the refrigerant, the amount of refrigerant to be injected into the compressor  200  may be adjusted according to the stored refrigerant amount. 
         [0049]    A refrigerant flow will be described below. 
         [0050]    The refrigerant decompressed by the first expansion unit  210  is stored in the phase separator  100  through the inflow part  110  and heat-exchanged with the refrigerant flowing into the internal heat-exchanger  145 . Then, the refrigerant is discharged through the outflow part  120 . The refrigerant discharged through the outflow part  120  is decompressed by the second expansion unit  220  and flows into the evaporator. 
         [0051]    At least one portion of the refrigerant discharged through the outflow part  120  is expanded by the second expansion unit  240  and then flows into the phase separator  100  through the first inflow tube  140 . Also, the refrigerant of the first inflow tube  140  flows into the internal heat-exchanger  145  and heat-exchanged with the refrigerant stored in the phase separator  100 . Then, the refrigerant is discharged to the outside of the phase separator  100  through the first outflow tube  150 . 
         [0052]    The refrigerant discharged through the first outflow tube  150  flows into the low pressure part of the compressor  200  through the low pressure injection passage  250 . 
         [0053]    The gaseous refrigerant of the two-phase refrigerant stored in the phase separator  100  is discharged through the gas separation part  130  and injected into the high pressure part of the compressor  200 . 
         [0054]    As described above, the refrigerant may be injected into the compressor  200  through the plurality of injection passages  235  and  250  to secure a sufficient refrigerant even though the heating load is large. Also, a refrigerant having a middle pressure may flow to reduce an operation load of the compressor  200 . Here, the middle pressure may be greater than a suction pressure of the compressor  200  and less than a discharge pressure of the compressor  200 . 
         [0055]      FIG. 4  is a view illustrating a refrigerant flow during the heating in a refrigerant cycle in which a phase separator is applied according to an embodiment.  FIG. 5  is a view illustrating a refrigerant flow during the cooling in a refrigerant cycle in which a phase separator is applied according to an embodiment. 
         [0056]    A refrigerant cycle of the air conditioner will be described with reference to  FIG. 4 . The air conditioner may include a four-way valve  320  for adjusting a flow direction of the refrigerant discharged from the compressor  200  according to a cooling or heating operation, an outdoor heat-exchanger  330  in which indoor air is heat-exchanged with outdoor air in an indoor room, and an accumulator  350  for temporarily storing the refrigerant flowing into the compression  200 . 
         [0057]    A refrigerant passing through the condenser flows into the phase separator  100  via the first expansion unit  210 . In detail, when the air conditioner is operated in the cooling mode, the refrigerant passing through the outdoor heat-exchanger  330  may flow into the phase separator  100 . Also, when the air conditioner is operated in the heating mode, the refrigerant passing through the indoor heat-exchanger  340  may flow into the phase separator  100 . 
         [0058]    The air conditioner may further include a plurality of check valves and a plurality of connection passages which adjust the refrigerant flow so that the phase separation and the refrigerant injection into the compressor are realized during the cooling operation or the heating operation. 
         [0059]    In detail, the air conditioner includes a first connection passage  312  connecting the outflow part  120  to the indoor heat-exchanger  340  and a first check valve  302  provided in the first connection passage  312 . The first check valve  302  is disposed in a passage defined between the second expansion unit  220  and the indoor heat-exchanger  340  to guide the refrigerant flow in one direction. 
         [0060]    The air conditioner further includes a second connection passage  314  branched from one point of the passage defined between the first check valve  302  and the indoor heat exchanger  340  and communicating with the inflow part  110 . A second check valve  304  through which the refrigerant flows only toward the inflow part  110  is disposed in the second connection passage  314 . 
         [0061]    The air conditioner further includes a third connection passage  316  through which the refrigerant flows from the outdoor heat-exchanger  330  into the inflow part  110 . A third check valve  306  through which the refrigerant flows from the outdoor heat-exchanger  330  into the inflow part  110  is disposed in the third connection passage  316 . 
         [0062]    The air conditioner further includes a fourth connection passage  318  branched from one point of the passage defined between the first check valve  302  and the second expansion unit  220  and communicating with the third connection passage  316 . A fourth check valve  308  through which the refrigerant flows from the first connection passage  312  into the third connection passage  316  is disposed in the fourth connection passage  318 . 
         [0063]    A refrigerant flow in a refrigerant cycle when the air conditioner is operated in the heating mode will be described with reference to  FIG. 4 . 
         [0064]    The refrigerant compressed by the compressor  200  flows into the indoor heat-exchanger  340  via the four-way valve  320 . The refrigerant condensed in the indoor heat-exchanger flows into the second connection passage  314 . Here, the first check valve  302  prevents the refrigerant from flowing into the first connection passage  312 . 
         [0065]    The refrigerant flowing into the second connection passage  314  is expanded by the first expansion unit  210  via the second check valve  304 . The refrigerant passing through the first expansion unit  210  flows into the phase separator  100  through the inflow part  110 . 
         [0066]    The gaseous refrigerant separated by the phase separator  100  is injected into the high pressure part of the compressor  200  through the high pressure injection passage  235 . The amount of refrigerant to be injected into the high pressure part may be adjusted by the injection valve  230 , and an opening degree of the injection valve  230  of the injection valve  230  may be adjusted according to a heating load. For example, when the heating load is large, the opening degree of the injection valve  230  may be increased. 
         [0067]    The gaseous and liquid refrigerants remaining in the phase separator  100  without being separated is discharged through the outflow part  120 . At least one portion of the refrigerant discharged through the outflow part  120  is bypassed into the first inflow tube  140  to flow into the phase separator  100 . Then, the refrigerant is heat-exchanged with the refrigerant stored in the phase separator  100  in the internal heat-exchanger  145 . 
         [0068]    The refrigerant heated in the internal heat-exchanger  145  is injected into the low pressure part of the compressor  200  through the low pressure injection passage  250 . The amount of refrigerant injected into the low pressure part may be adjusted by the third expansion unit  240 . An opening degree of the third expansion unit  240  may be adjusted according to a heating load. For example, when the heating load is large, the opening degree of the third expansion unit  240  may be increased. 
         [0069]    The refrigerant discharged through the outflow part  120  is expanded by the second expansion unit  220  to flow into the fourth connection passage  318 . 
         [0070]    The refrigerant may flow from the first connection passage  312  into the indoor heat-exchanger  340  by the first check valve  302 . However, since the refrigerant discharged from the indoor heat-exchanger  340  has a pressure greater than that of the refrigerant of an inlet side of the first check valve  302 , the refrigerant passing through the second expansion unit  220  may flow into the fourth connection passage  318 . 
         [0071]    The refrigerant passing through the fourth check valve  308  flows into the outdoor heat-exchanger  330  through the third connection passage  316 . 
         [0072]    The refrigerant may flow from the third connection passage  316  into the inflow part  110  by the third check valve  306 . However, since the refrigerant of an inflow part side has a pressure greater than that of the inlet side of the outdoor heat-exchanger  330 , the refrigerant may flow into the outdoor heat-exchanger  330  via the fourth expansion unit  308  and the third connection passage  316 . 
         [0073]    The refrigerant is evaporated in the outdoor heat-exchanger  330 , and the refrigerant passing through the outdoor heat-exchanger  330  flows into the accumulator  350  via the four-way valve  320 . The gaseous refrigerant of the refrigerant stored in the accumulator  350  flows into the compressor  200 . This refrigerant cycle may be repeatedly performed. 
         [0074]    A refrigerant flow in a refrigerant cycle when the air conditioner is operated in the cooling mode will be described with reference to  FIG. 5 . 
         [0075]    The refrigerant compressed by the compressor  200  flows into the outdoor heat-exchanger  330  via the four-way valve  320 . The condensed refrigerant passing through the outdoor heat-exchanger  330  flows into the third connection passage  316 . The refrigerant flowing into the third connection passage  316  flows into the inflow part  110  via the third check valve  306  and the first expansion unit  210 . 
         [0076]    The refrigerant flowing into the third connection passage  316  does not flow into the second connection passage  314  and the fourth connection passage  318  by the fourth check valve  308 , respectively. 
         [0077]    The refrigerant flowing into the inflow part  110  passes through the phase separator  100 . Since a flow of the refrigerant injected from the phase separator  100  into the compressor  200  is equal to that of  FIG. 4 , its description will be omitted. 
         [0078]    The refrigerant discharged from the outflow part  150  flows into the first connection passage  312  via the second expansion unit  220  and flows into the indoor heat-exchanger  340  via the first check valve  302 . 
         [0079]    Since the refrigerant flowing into the third connection part  316  has a pressure greater than that of the refrigerant flowing into the first connection passage  312 , the inflow of the refrigerant into the second connection passage  314  and the fourth connection passage  318  may be limited. The refrigerant passing through the first connection passage  312  flows into the indoor heat-exchanger  340 . 
         [0080]    The refrigerant evaporated in the indoor heat-exchanger  340  flows into the accumulator  350  via the four-way valve  320 . The gaseous refrigerant of the refrigerant stored in the accumulator  350  flows into the compressor  200 . This refrigerant cycle may be repeatedly performed. 
         [0081]    According to the proposed embodiment, since the refrigerant is injected into the compressor including the multiple stage compression parts, the circulation amount of refrigerant may be increased to improve the cooling or heating performance. 
         [0082]    Also, the internal heat-exchanger may be disposed within the phase separator to improve the gas and liquid separation performance. Also, since the phase separator and the internal heat-exchanger may not be separately provided, the assembly of the air conditioner may be improved and also the compact air conditioner may be realized. 
         [0083]    Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.