Heat pump air conditioner

Abstract

A heat pump air conditioner includes an outdoor unit for heating use only for supplementing heating capacity when additional heating capacity must be provided to the heating capacity of an outdoor unit for heating and cooling in a heating mode. Since the outdoor unit for heating use only is installed independent from the outdoor units for heating and cooling use, such that the outdoor unit for heating use only can supplement the heating capacity only when the additional heating capacity is required in addition to the heating capacity of the outdoor units for heating and cooling use in the heating mode, in order to correspond to the heating load in cold climes, there is no need to install an outdoor unit having larger heating capacity than the required heating capacity. Thus, costs for installation and management are reduced.

1 . A heat pump air conditioner comprising: 
 at least one outdoor unit for heating and cooling use including a compressor, a four-way valve, and an outdoor heat exchanger;    at least one indoor unit for heating and cooling use connected to the outdoor unit by a refrigerant tube; and    an outdoor unit for heating use only installed independently from the outdoor unit for heating and cooling use and supplementing heating capacity of the heat pump air conditioner when there is a need to provide additional heating capacity to the heating capacity of the outdoor unit for heating and cooling use in a heating mode.    
   
   
       2 . The heat pump air conditioner as set forth in  claim 1 , wherein the outdoor unit for heating use only comprises: 
 an additional compressor; and    an additional outdoor heat exchanger.    
   
   
       3 . The heat pump air conditioner as set forth in  claim 2 , wherein the outdoor unit for heating use only comprises a valve device for opening and closing a passage connected to the indoor unit.  
   
   
       4 . The heat pump air conditioner as set forth in  claim 3 , wherein the valve device comprises an electronic expansion valve opened to expand refrigerant introduced from the indoor unit for heating and cooling use in the heating mode, and closed to prevent the refrigerant from being introduced from the indoor unit for heating and cooling use in the cooling mode.  
   
   
       5 . The heat pump air conditioner as set forth in  claim 4 , wherein the valve device further comprises a check valve for preventing the refrigerant from flowing in reverse to the additional compressor in the cooling mode.  
   
   
       6 . The heat pump air conditioner as set forth in  claim 5 , wherein the valve device is installed in a discharge passage of the additional compressor.  
   
   
       7 . The heat pump air conditioner as set forth in  claim 5 , wherein the outdoor unit for heating use only further comprises an accumulator installed to an inlet port of the additional compressor to accumulate liquid refrigerant from the refrigerant sucked into the additional compressor.  
   
   
       8 . The heat pump air conditioner as set forth in  claim 1 , wherein the outdoor unit for heating and cooling use further comprises an expansion device for expanding the refrigerant introduced from the indoor unit for heating and cooling use in the heating mode.  
   
   
       9 . The heat pump air conditioner as set forth in  claim 8 , wherein the compressor comprises a plurality of compressors.  
   
   
       10 . The heat pump air conditioner as set forth in  claim 9 , wherein a common accumulator connects the compressors to one another.  
   
   
       11 . A heat pump air conditioner comprising: 
 at least one outdoor unit for heating and cooling use having a compressor, a four-way valve, and an outdoor heat exchanger;    at least one indoor unit for heating and cooling use connected to the outdoor unit for heating and cooling use by a refrigerant tube; and    an outdoor unit for cooling use only installed independently from the outdoor unit and supplementing cooling capacity of the heat pump air conditioner when there is a need to provide additional cooling capacity to the cooling capacity of the outdoor unit for heating and cooling use in a cooling mode.    
   
   
       12 . The heat pump air conditioner as set forth in  claim 11 , wherein the outdoor unit for cooling use only comprises: 
 an additional compressor; and    an additional outdoor heat exchanger.    
   
   
       13 . The heat pump air conditioner as set forth in  claim 12 , wherein the outdoor unit for cooling use only further comprises a valve device for opening and closing a passage connected to the indoor unit for heating and cooling use.  
   
   
       14 . The heat pump air conditioner as set forth in  claim 13 , wherein the valve device comprises an electronic expansion valve opened to expand refrigerant introduced from the additional outdoor heat exchanger in the cooling mode, and closed to prevent the refrigerant from being introduced from the additional outdoor heat exchanger in the heating mode.  
   
   
       15 . The heat pump air conditioner as set forth in  claim 14 , wherein the outdoor unit for cooling use only further comprises a check valve installed in a discharge passage of the additional compressor to prevent the refrigerant from flowing in reverse to the additional compressor.  
   
   
       16 . The heat pump air conditioner as set forth in claim  15 , wherein the outdoor unit for cooling use only further comprises an accumulator installed to an inlet port of the additional compressor to accumulate liquid refrigerant from the refrigerant sucked into the additional compressor.  
   
   
       17 . The heat pump air conditioner as set forth in  claim 11 , wherein the outdoor unit for heating and cooling use further comprises an expansion device for expanding the refrigerant passed through the outdoor heat exchanger in the cooling mode.  
   
   
       18 . The heat pump air conditioner as set forth in  claim 17 , wherein the compressor comprises a plurality of compressors.  
   
   
       19 . The heat pump air conditioner as set forth in  claim 18  wherein, the plural compressors are connected to a common accumulator.  
   
   
       20 . A heat pump air conditioner comprising: 
 at least one outdoor unit for heating and cooling use having a compressor, a four-way valve, and an outdoor heat exchanger;    at least one indoor unit for heating and cooling use connected to the outdoor unit for heating and cooling use by a refrigerant tube;    an outdoor unit for cooling use only installed independently from the outdoor unit and supplementing additional cooling capacity of the heat pump air conditioner when there is a need to add the additional cooling capacity to the cooling capacity of the outdoor unit for heating and cooling use in a cooling mode; and    a valve device for opening and closing a passage connected to the indoor unit for heating and cooling use.