Multi-air condition system and method for controlling the same

Abstract

Multi-air condition system including a plurality of outdoor units, a pressure equalizing pipe connected such that refrigerant can flow among the outdoor units, for eliminating refrigerant pressure differences, and imbalance of an amount of refrigerant flow among the outdoor units, and control valves at portions of the pressure equalizing pipe connected to the outdoor units respectively, for cutting off introduction of the refrigerant to a relevant outdoor unit under the control of a controller.

1 . A multi-air condition system comprising: 
 a plurality of outdoor units;    a pressure equalizing pipe connected such that refrigerant can flow among the outdoor units, for eliminating refrigerant pressure differences, and imbalance of an amount of refrigerant flow among the outdoor units; and    control valves at portions of the pressure equalizing pipe connected to the outdoor units respectively, for cutting off introduction of the refrigerant to a relevant outdoor unit under the control of a controller.    
   
   
       2 . The multi-air condition system as claimed in  claim 1 , wherein the control valve is a solenoid valve.  
   
   
       3 . The multi-air condition system as claimed in  claim 1 , wherein the control valve is a 2-way solenoid valve.  
   
   
       4 . The multi-air condition system as claimed in  claim 1 , wherein the control valve is of a normally open type.  
   
   
       5 . The multi-air condition system as claimed in  claim 1 , wherein the outdoor unit includes a 4-way valve, and a compression unit, an outdoor heat exchanger, and an accumulator connected to the 4-way valve, and 
 the pressure equalizing pipe is connected to the refrigerant pipe between the 4-way valve and the outdoor heat exchanger in each of the outdoor units.    
   
   
       6 . The multi-air condition system as claimed in  claim 5 , wherein the 4-way valve is connected to an outlet side refrigerant pipe of the compression unit, an inlet side of the outdoor heat exchanger, an inlet side refrigerant pipe of the accumulator, and an indoor unit side refrigerant pipe.  
   
   
       7 . The multi-air condition system as claimed in  claim 1 , wherein the plurality of outdoor units include; 
 a main unit having a variable speed compressor with a variable operation frequency, and    at least one subunit having at least one single speed compressor with a constant operation frequency.    
   
   
       8 . The multi-air condition system as claimed in  claim 1 , wherein the control valve is mounted only on a portion having the pressure equalizing pipe connected to the subunit.  
   
   
       9 . The multi-air condition system as claimed in  claim 7 , further comprising a manual valve to be opened/closed manually mounted on a portion of the pressure equalizing pipe connected to the main unit.  
   
   
       10 . The multi-air condition system as claimed in  claim 9 , wherein the manual valve is of a normally open type.  
   
   
       11 . A multi-air condition system comprising: 
 a plurality of outdoor units having a main unit in operation when the multi-air condition system is in operation always, and subunits excluding the main unit, each outdoor unit including a compression unit having at least one compressor, an accumulator, an outdoor heat exchanger, and a 4-way valve connected to an outlet side refrigerant pipe of the compression unit, an inlet side refrigerant pipe of the outdoor heat exchanger;    a pressure equalizing pipe connected among inlet side refrigerant pipes of the outdoor heat exchangers of the outdoor units, for eliminating pressure differences, and imbalance of refrigerant flow amounts among outdoor units in operation;    a manual valve of a normally open type mounted at a portion having the pressure equalizing pipe connected to the main unit, for opening/closing manually; and    a solenoid valve of a normally open type each mounted at a portion having the pressure equalizing pipe connected to each of the subunits, for automatic cut off of a refrigerant flow toward an outdoor unit which is not in operation under the control of a controller.    
   
   
       12 . The multi-air condition system as claimed in  claim 11 , wherein the main unit includes at least one variable speed compressor of which operation frequency varies.  
   
   
       13 . A method for controlling a multi-air condition system, comprising the steps of: 
 putting an air conditioner into operation;    checking operation of outdoor units; and    closing control valves connected to outdoor units which are not in operation for cutting off introduction of refrigerant into the outdoor unit which are not in operation.    
   
   
       14 . The method as claim in  claim 13 , wherein operation of the outdoor unit is determined by checking operation of a compressor.  
   
   
       15 . The method as claim in  claim 13 , further comprising the steps of: 
 checking open/close of the control valves after checking operation of the outdoor units; and    opening the control valve connected to the outdoor unit in operation if the control valve is in a closed state.    
   
   
       16 . The multi-air condition system as claimed in  claim 2 , wherein the control valve is a 2-way solenoid valve.  
   
   
       17 . The multi-air condition system as claimed in  claim 2 , wherein the control valve is of a normally open type.