Abstract:
Disclosed herein is a refrigerator. In a refrigeration cycle including a channel switching valve to selectively supply a refrigerant to a first evaporator side and/or a second evaporator side and hot pipes, a hot pipe on a freezing chamber side and a hot pipe on a refrigerating chamber are disposed upstream and downstream of the channel switching valve, respectively to reduce unbalance in amounts of the refrigerant and in the amounts of generated heat.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of Korean Patent Application No. 10-2009-0129106, filed on Dec. 22, 2009 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. 
       BACKGROUND 
       [0002]    1. Field 
         [0003]    Embodiments discussed herein relate to a refrigerator having a refrigeration cycle including evaporators provided respectively in a refrigerating chamber and a freezing chamber and an operation control method thereof. 
         [0004]    2. Description of the Related Art 
         [0005]    Generally, a refrigerator is an apparatus that supplies low-temperature cool air into a storage chamber to store food in the storage chamber at low temperature in a fresh state. The refrigerator may include a freezing chamber to store food at below freezing temperature and a refrigerating chamber to store food at a temperature slightly higher than freezing temperature. 
         [0006]    Cool air to be supplied into the refrigerator is generated through heat exchange of a refrigerant. A refrigeration cycle of compression, condensation, expansion, and evaporation is repetitively performed to continuously supply cool air into the refrigerator. The supplied cool air is uniformly diffused in the refrigerator by convection to store or keep food in the refrigerator at a predetermined temperature. 
         [0007]    A refrigerator is disclosed in which a refrigeration cycle includes evaporators provided respectively in a refrigerating chamber and a freezing chamber and a three-way valve to supply a refrigerant discharged from a condenser to the evaporator on the refrigerating chamber side or the evaporator on the freezing chamber side, thereby controlling flow of the refrigerant according to an operation mode of the refrigerator. 
         [0008]    When cool air inside the refrigerator and hot air outside the refrigerator directly/indirectly contact each other, dew may be formed in the perimeters of openings of the refrigerating chamber and the freezing chamber due to a temperature difference. A refrigerator is also disclosed in which a hot pipe extending from the condenser of the refrigeration cycle is arranged in the perimeters of the openings of the refrigerating chamber and the freezing chamber to prevent dew formation. 
         [0009]    The hot pipe is a refrigerant pipe mounted at a high-pressure side. Generally, the hot pipe is arranged upstream of the three-way valve throughout the perimeters of the openings of the refrigerating chamber and the freezing chamber to prevent dew formation at the openings of the refrigerating chamber and the freezing chamber through dissipation of heat from a high-temperature refrigerant gas during the operation of a compressor. 
         [0010]    In the refrigeration cycle including the hot pipe, energy loss may occur due to unbalance in the amounts of heat generated from the hot pipe on the freezing chamber side and the hot pipe on the refrigerating chamber side and unbalance in the amount of the refrigerant. 
       SUMMARY 
       [0011]    It is an aspect of the embodiments to provide a refrigerator that reduces unbalance in the amount of a refrigerant according to an operation mode of a refrigeration cycle, thereby improving cooling efficiency of a refrigerating chamber and a freezing chamber. 
         [0012]    It is another aspect to provide a refrigerator that reduces unbalance in the amount of heat generated from a hot pipe, thereby reducing power consumption. 
         [0013]    Additional aspects will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the embodiments. 
         [0014]    In accordance with one aspect, a refrigerator includes a compressor, a condenser, a hot pipe, a first circulation channel to cool a refrigerating chamber, a second circulation channel to cool a freezing chamber, and a channel switching valve to perform switching between the circulation channels, wherein the hot pipe includes a first hot pipe on a freezing chamber side and a second hot pipe on a refrigerating chamber side, a first end of the first hot pipe is connected to the condenser and a second end of the first hot pipe an inlet of the channel switching valve, and the second hot pipe is connected to an outlet of the channel switching valve. 
         [0015]    The second circulation channel may be connected to another outlet of the channel switching valve, and the second circulation channel may be connected to the compressor via a second expansion device and a second evaporator on the freezing chamber side. 
         [0016]    The first circulation channel may be connected to a second evaporator on the freezing chamber side and the compressor via the second hot pipe, a first expansion device, a first evaporator on the refrigerating chamber side, and a third expansion device in a series. 
         [0017]    The first circulation channel may be connected to a first evaporator on the refrigerating chamber side and the compressor via the second hot pipe and a first expansion device. 
         [0018]    The channel switching valve may include a three-way valve having one inlet connected to an outlet of the first hot pipe and two outlets connected respectively to the first circulation channel and the second circulation channel. 
         [0019]    In accordance with another aspect, a refrigerator includes a compressor, a condenser, a first hot pipe on a freezing chamber side and a second hot pipe on a refrigerating chamber site, and a controller to control a first operation mode to cool a refrigerating chamber and a second operation mode to cool a freezing chamber, wherein the controller controls a refrigerant channel such that a refrigerant discharged from the condenser cools the freezing chamber via the first hot pipe and the second hot pipe returns to the compressor during an operation in the first operation mode. 
         [0020]    The controller may control a refrigerant channel such that the refrigerant flows to the first hot pipe during an operation in the second operation mode. 
         [0021]    The controller may control a refrigerant channel such that the refrigerant discharged from the condenser cools the refrigerating chamber and the freezing chamber via the first hot pipe and the second hot pipe and returns to the compressor during an operation in the first operation mode. 
         [0022]    The controller may control a refrigerant channel such that the refrigerant discharged from the condenser cools the refrigerating chamber via the first hot pipe and the second hot pipe and returns to the compressor during an operation in the first operation mode. 
         [0023]    In accordance with a further aspect, an operation control method of a refrigerator including a compressor, a condenser, a first hot pipe on a freezing chamber side, a second hot pipe on a refrigerating chamber side, a refrigerating chamber, and a freezing chamber includes determining whether the refrigerating chamber or the freezing chamber is to be cooled and controlling a refrigerant discharged from the condenser to cool the freezing chamber via the first hot pipe upon determining that the freezing chamber is to be cooled. 
         [0024]    The operation control method may further include controlling the refrigerant discharged from the condenser to cool the refrigerating chamber via the first hot pipe and the second hot pipe upon determining that the refrigerating chamber is to be cooled. 
         [0025]    The operation control method may further include controlling the refrigerant to cool the freezing chamber, after cooling the refrigerating chamber, and return to the compressor. 
         [0026]    The operation control method may further include controlling the refrigerant to return to the compressor after cooling the refrigerating chamber. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0027]    These and/or other aspects will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which: 
           [0028]      FIG. 1  is a schematic perspective view illustrating a refrigeration cycle of a refrigerator according to an embodiment; 
           [0029]      FIG. 2  is a view illustrating a first operation mode of a refrigeration cycle according to an embodiment; 
           [0030]      FIG. 3  is a view illustrating a second operation mode of the refrigeration cycle of  FIG. 2 ; 
           [0031]      FIG. 4  is a view illustrating a first operation mode of a refrigeration cycle according to another embodiment; and 
           [0032]      FIG. 5  is a view illustrating a second operation mode of the refrigeration cycle of  FIG. 4 . 
       
    
    
     DETAILED DESCRIPTION 
       [0033]    Reference will now be made in detail to the embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. 
         [0034]    Referring to  FIG. 1 , a refrigerator according to an embodiment may include a refrigerator body  10  and a plurality of storage chambers  12  and  13  partitioned by a partition  11 . 
         [0035]    The storage chambers  12  and  13  include a refrigerating chamber  12  to store food at a temperature slightly higher than freezing temperature and a freezing chamber  13  to store food at below freezing temperature. In the storage chambers  12  and  13  may be respectively provided evaporators  28  and  29  to perform heat exchange with air in the storage chambers  12  and  13 . 
         [0036]    The evaporators  28  and  29  include a first evaporator  28  mounted in the refrigerating chamber  12  and a second evaporator  29  mounted in the freezing chamber  13 , respectively. The evaporators  28  and  29  are connected to a refrigeration cycle to cool the respective storage chambers  12  and  13 . 
         [0037]    The refrigeration cycle includes a compressor  21  to compress a gas refrigerant into a high-temperature and high-pressure state, a condenser  22  to condense the gas refrigerant compressed by the compressor  21  into a liquid state, expansion devices  24  and  25  (see  FIG. 2 ) to convert the liquid refrigerant into a low-temperature and low-pressure state, and evaporators  28  and  29  to evaporate the low-temperature and low-pressure liquid refrigerant to generate cool air. These are connected to one another via a refrigerant pipe  30  such that the refrigerant is circulated while the phase of the refrigerant is changed. 
         [0038]    The expansion devices  24  and  25  may include capillary tubes or expansion valves. The evaporators  28  and  29  may be provided in the respective storage chambers  12  and  13 . 
         [0039]    Also, the refrigeration cycle may further include a dryer  26  provided between the compressor  22  and the expansion devices  24  and  25  to remove moisture from the refrigerant supplied from the condenser  22  and an accumulator  27  provided between the evaporators  28  and  29  and the compressor  21  to restrain the supply of the liquid refrigerant to the condenser  21 . 
         [0040]    In the refrigerant pipe  30  connected between the condenser  22  and the expansion devices  24  and  25  may provided a cluster pipe  31  arranged at the top and opposite sidewalls of the refrigerator body  10  in a serpentine fashion and hot pipes  32  and  33  arranged along the perimeter of a front opening of the refrigerator body  10 . 
         [0041]    The hot pipes  32  and  33  extend from the condenser  22  such that the hot pipes  32  and  33  are buried along the perimeter of the opening of the refrigerator body  10 . Formation of dew at the front of the refrigerator body  10  due to a temperature difference between the inside and outside of the refrigerator body  10  is prevented, and the amount of heat dissipated from the high-pressure side is increased, by the dissipation of heat from the high-temperature refrigerant flowing in the hot pipes  32  and  22 . 
         [0042]    The hot pipes  32  and  33  may include, a first hot pipe  32  buried in the perimeter of the refrigerator body  10  constituting the freezing chamber  13  and a second hot pipe  33  buried in the perimeter of the refrigerator body  10  constituting the refrigerating chamber  12 . 
         [0043]    Generally, a hot pipe is connected to a refrigerant pipe. The inlet and outlet of the hot pipe are connected respectively to the outlet of a high-pressure side refrigerant pipe and the inlet of a valve to control the flow of a refrigerant to a refrigerating chamber or freezing chamber evaporator. 
         [0044]    In this case, a high-temperature refrigerant always flows in the hot pipe during the operation of a compressor, with the result that the amount of heat generated from a hot pipe on the refrigerating chamber side, the temperature of which is relatively low, is excessive, thereby lowering energy efficiency. 
         [0045]    In this embodiment, therefore, a channel switching valve may be provided on a refrigerant circulation channel on the second hot pipe inlet side buried in the perimeter of the opening of the refrigerator body constituting the refrigerating chamber  12  to prevent lowering of energy efficiency of the refrigerator due to excessive heat generation from the hot pipe. 
         [0046]    Hereinafter, the refrigerant circulation channel of the refrigeration cycle will be described.  FIG. 2  is a schematic view illustrating the construction of a refrigeration cycle  20  according to an embodiment. In this embodiment, the refrigeration cycle is configured such that a first evaporator to generate cool air for the refrigerating chamber and a second evaporator to generate cool air for the freezing chamber are connected in series. 
         [0047]    As shown in  FIG. 2 , the refrigeration cycle  20  is configured such that a condenser  22  is connected to a high-pressure side discharge port of a compressor  21 , and a first hot pipe  32  buried in the perimeter of the opening of the freezing chamber  13  in  FIG. 1  is connected to the outlet of the condenser  22 . 
         [0048]    A channel switching valve  34  is connected to the outlet of the first hot pipe  32 . The channel switching valve  34  may include a three-way valve having one inlet and two outlets. The outlets of the channel switching valve  34  may be connected respectively to a first circulation channel  35  and a second circulation channel  36 . 
         [0049]    The channel switching valve  34  is not particularly restricted as long as one of the outlets is selectively opened, or bidirectional opening and closing is performed. 
         [0050]    A second hot pipe  33  buried in the perimeter of the opening of the refrigerating chamber  12  is connected to the outlet of the channel switching valve  34  connected to the first circulation channel  35 . A first expansion device  24  for the refrigerating chamber and a first evaporator  28  are sequentially connected to the outlet of the second hot pipe  33 . 
         [0051]    A second expansion device  25  for the freezing chamber and a second evaporator  29  are sequentially connected to the outlet of the channel switching valve  34  connected to the second circulation channel  36 . The outlet of the second evaporator  29  is connected to the compressor  21  via a suction pipe  37 . 
         [0052]    Also, the outlet of the first evaporator  28  and the inlet of the second evaporator  29  are connected in series via a connection refrigerant pipe  38 . A third expansion device  39  is mounted on the connection refrigerant pipe  38 . 
         [0053]    Hereinafter, the operation of the refrigeration cycle of  FIG. 2  will be described. 
         [0054]    In this embodiment, the refrigeration cycle may include a first operation mode to simultaneously cool the refrigerating chamber  12  and the freezing chamber  13 , a second operation mode to cool the freezing chamber  13  alone, and a controller  100  to control the first operation mode and the second operation mode. 
         [0055]    The controller  100  may be a microprocessor or microcontroller including a central processing unit (CPU) to perform at least one computer command to control operations of the respective components of the refrigerator according to manipulation set by a user or a predetermined program. 
         [0056]    In the first operation mode as shown in  FIG. 2 , a refrigerant, compressed by and discharged from the compressor  21 , is introduced into the condenser  22 . The refrigerant, condensed by the condenser  22 , flows to the channel switching valve  34  via the first hot pipe  32 . 
         [0057]    At this time, the channel switching valve  34  opens only the first circulation channel  35  under the control of the controller  100 . Consequently, the refrigerant, introduced into the channel switching valve  34 , is introduced into the first evaporator  28  via the second hot pipe  33  and the first expansion device  24  to cool the refrigerating chamber  12 . 
         [0058]    The refrigerant, discharged from the first evaporator  28 , is introduced into the second evaporator  29  via the third expansion device  39  to cool the freezing chamber  13 . The refrigerant, discharged from the second evaporator  29 , returns to the compressor  21  via the suction pipe  37 . 
         [0059]    In the second operation mode as shown in  FIG. 3 , a refrigerant, compressed by and discharged from the compressor  21 , is introduced into the condenser  22 . The refrigerant, condensed by the condenser  22 , flows to the channel switching valve  34  via the first hot pipe  32 . 
         [0060]    At this time, the channel switching valve  34  opens only the second circulation channel  36  under the control of the controller  100 . Consequently, the refrigerant, introduced into the channel switching valve  34 , cools the freezing chamber  13  via the second expansion device  25  and the second evaporator  29 . The refrigerant, discharged from the second evaporator  29 , returns to the compressor  21  via the suction pipe  37 . 
         [0061]    That is, the controller  100  determines whether the refrigerating chamber  12  or the freezing chamber  13  is to be cooled. Upon determining that the freezing chamber  13  is to be cooled, the controller  100  controls the second circulation channel  36  of the channel switching valve  34  such that the refrigerant discharged from the condenser  22  cools the freezing chamber  13  via the first hot pipe  32 . Upon determining that the refrigerating chamber  12  is to be cooled, the controller  100  controls the first circulation channel  35  of the channel switching valve  34  such that the refrigerant discharged from the condenser  22  cools the refrigerating chamber  12  via the first hot pipe  32  and the second hot pipe  33 . 
         [0062]    Meanwhile, the amount of a refrigerant optimally filled in the refrigeration cycle may be changed depending upon a refrigerating operation or a freezing operation. Generally, an amount of a refrigerant between optimal amounts of a refrigerant for the refrigerating and freezing operations is filled in the refrigeration cycle. 
         [0063]    As a result, the refrigerant is excessive in one of the refrigerating and freezing operations and is insufficient in the other of the refrigerating and freezing operations. 
         [0064]    That is, the refrigerant is excessive in the refrigerating operation, and the refrigerant is insufficient in the freezing operation, with the result that energy loss may occur due to unbalance in the amount of the refrigerant. In this embodiment, such energy loss may be minimized. 
         [0065]    Referring to  FIG. 2 , in the first operation mode of the refrigeration cycle, a larger amount of the refrigerant than the optimal amount of the refrigerant to be introduced into the first evaporator  28  is filled. At this time, the refrigerant flows to the second hot pipe  33 , thereby preventing the refrigerant from being excessively introduced into the first evaporator  28 . 
         [0066]    Referring to  FIG. 3 , in the second operation mode of the refrigeration cycle, a smaller amount of the refrigerant than the optimal amount of the refrigerant to be introduced into the second evaporator  29  is filled. At this time, the refrigerant does not flow to the second hot pipe  33 , thereby preventing the refrigerant from being insufficiently introduced into the second evaporator  29 . 
         [0067]    Consequently, in a conventional structure in which the refrigerant flows to both the first hot pipe  32  and the second hot pipe  33  during the operation of the compressor  21 , energy efficiency is lowered due to unbalance in the amount of the refrigerant. In this embodiment, the unbalance in the amount of the refrigerant is relatively reduced, thereby improving energy efficiency of the refrigerator. 
         [0068]    Also, since the amount of heat to be provided to prevent dew formation is generally calculated based on the first hot pipe  32  on the freezing chamber side, heat is excessively generated from the second hot pipe  33  on the refrigerating chamber side, thereby excessively increasing thermal load of the refrigerator. In this embodiment, the amount of heat generated from the second hot pipe  33  of the refrigeration cycle is relatively reduced as compared with the amount of heat generated from the first hot pipe  32 , with the result that increase of thermal load due to excessive generation of heat is prevented, thereby improving energy efficiency of the refrigerator. 
         [0069]      FIG. 4  is a schematic view illustrating the construction of a refrigeration cycle  40  according to another embodiment. 
         [0070]    Hereinafter, components of this embodiment identical to those of the previous embodiment are denoted by the same reference numerals, and a detailed description thereof will not be given. 
         [0071]    In this embodiment, the refrigeration cycle is configured such that a first evaporator to generate cool air for the refrigerating chamber and a second evaporator to generate cool air for the freezing chamber are connected in parallel, unlike the previous embodiment. 
         [0072]    As shown in  FIG. 4 , the refrigeration cycle  40  is configured such that a condenser  22  is connected to a high-pressure side discharge port of a compressor  21 , and a first hot pipe  32  buried in the perimeter of the opening of the freezing chamber  13  in  FIG. 1  is connected to the outlet of the condenser  22 . 
         [0073]    A channel switching valve  34  is connected to the outlet of the first hot pipe  32 . The channel switching valve  34  may include a three-way valve having one inlet and two outlets. The outlets of the channel switching valve  34  may be connected respectively to a first circulation channel  41  on the refrigerating chamber side and a second circulation channel  42  on the freezing chamber side. 
         [0074]    A second hot pipe  33  buried in the perimeter of the opening of the refrigerating chamber  12  is connected to the outlet of the channel switching valve  34  connected to the first circulation channel  41 . A first expansion device  24  for the refrigerating chamber and a first evaporator  28  are sequentially connected to the outlet of the second hot pipe  33 . 
         [0075]    Referring to  FIG. 4 , the second hot pipe  33 , the first expansion device  24 , the first evaporator  28 , and a suction pipe  37  are sequentially connected to the outlet of the channel switching valve  34  connected to the first circulation channel  41 . A second expansion device  25 , a second evaporator  29 , and the suction pipe  37  are sequentially connected to the outlet of the channel switching valve  34  connected to the second circulation channel  42 . 
         [0076]    The outlet of the first evaporator  28  is connected to a first discharge refrigerant pipe  43 , which is a discharge channel of the refrigerating chamber  12 . The outlet of the second evaporator  29  is connected to a second discharge refrigerant pipe  44 , which is a discharge channel of the freezing chamber  13 . 
         [0077]    A refrigerant discharged from the first discharge refrigerant pipe  43  and a refrigerant discharged from the second discharge refrigerant pipe  44  are mixed before introduction thereof into the compressor  21 . The joint between the first discharge refrigerant pipe  43  and the second discharge refrigerant pipe  44  is connected to the inlet of the compressor  21  via the suction pipe  37 . 
         [0078]    A check valve  45  is mounted on the second discharge refrigerant pipe  44  is mounted to prevent backward flow of the refrigerant from the first discharge refrigerant pipe  43 . 
         [0079]    Hereinafter, the operation of the refrigeration cycle of  FIG. 4  will be described. 
         [0080]    In this embodiment, the refrigeration cycle may include a first operation mode to operate the refrigerating chamber  12 , a second operation mode to operate the freezing chamber  13 , and a controller to control the first operation mode and the second operation mode. 
         [0081]    In the first operation mode as shown in  FIG. 4 , a refrigerant, compressed by and discharged from the compressor  21 , is introduced into the condenser  22 . The refrigerant, condensed by the condenser  22 , flows to the channel switching valve  34  via the first hot pipe  32 . 
         [0082]    At this time, the channel switching valve  34  opens only the first circulation channel  41  under the control of the controller. Consequently, the refrigerant, introduced into the channel switching valve  34 , sequentially flows through the second hot pipe  33 , the first expansion device  24 , and the first evaporator  28 , and returns to the compressor via the suction pipe  37 . 
         [0083]    In the refrigeration cycle in which a larger amount of the refrigerant than the optimal amount of the refrigerant to be introduced into the first evaporator  28  is filled, therefore, the refrigerant flows to the second hot pipe  33 , thereby preventing the refrigerant from being excessively introduced into the first evaporator  28 . 
         [0084]    Also, the amount of heat generated from the second hot pipe  33  is relatively reduced as compared with the amount of heat generated from the first hot pipe  32 , with the result that increase of thermal load due to excessive generation of heat from the second hot pipe  33  is prevented. 
         [0085]    In the second operation mode as shown in  FIG. 5 , a refrigerant, compressed by and discharged from the compressor  21 , is introduced into the condenser  22 . The refrigerant, condensed by the condenser  22 , flows to the channel switching valve  34  via the first hot pipe  32 . 
         [0086]    At this time, the channel switching valve  34  opens only the second circulation channel  42  under the control of the controller. Consequently, the refrigerant, introduced into the channel switching valve  34  sequentially flows through the second expansion device  25  and the second evaporator  29 , and returns to the compressor  21  via the suction pipe  37 . 
         [0087]    In the refrigeration cycle in which a smaller amount of the refrigerant than the optimal amount of the refrigerant to be introduced into the second evaporator  29  is filled, therefore, the refrigerant does not flow to the second hot pipe  33 , thereby preventing the refrigerant from being insufficiently introduced into the second evaporator  29 . 
         [0088]    In the refrigeration cycle having the coolant circulation channel as described above, therefore, unbalance in the amount of the refrigerant and unbalance in the amounts of heat generated from the hot pipes  32  and  33  depending upon the operation modes are reduced, thereby improving energy efficiency of the refrigerator. 
         [0089]    As is apparent from the above description, unbalance in the amount of the refrigerant and unbalance in the amounts of heat generated from the hot pipes depending upon the operation modes of the refrigeration cycle are reduced, thereby improving energy efficiency of the refrigerator. 
         [0090]    Although a few embodiments have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit thereof, the scope of which is defined in the claims and their equivalents.