System and method for controlling air conditioner

Abstract

A system for controlling an air conditioner includes a plurality of outdoor units each having at least one compressor and an outdoor heat exchanger, an indoor unit connected to the outdoor units by a refrigerant tube, the indoor unit having an indoor heat exchanger, and a pressure regulating tube for equalizing pressure according to an operation mode. The pressure regulating tube is connected between the outdoor units.

1 . A system for controlling an air conditioner, comprising: 
 a plurality of outdoor units each having at least one compressor and an outdoor heat exchanger;    at least one indoor unit connected to at least one of the outdoor units by a refrigerant tube, the indoor unit having an indoor heat exchanger; and    a pressure regulating tube for equalizing pressure according to an operation mode, the pressure regulating tube being connected to the outdoor units.    
   
   
       2 . The system according to  claim 1 , wherein the pressure regulating tube is varied in a connection location to the outdoor heat exchangers according to the operation mode.  
   
   
       3 . The system according to  claim 1 , wherein the pressure regulating tube is connected between refrigerant tubes extending from rear ends of the heat exchangers where low pressure is formed in a heating mode.  
   
   
       4 . The system according to  claim 1 , wherein the pressure regulating tube is connected between refrigerant tubes extending from front ends of the outdoor heat exchangers where high pressure is formed in a cooling mode.  
   
   
       5 . The system according to  claim 1 , wherein the pressure regulating tube has a diameter less that of the refrigerant tube.  
   
   
       6 . The system according to  claim 1 , wherein the outdoor units comprise first and second outdoor units, the first outdoor unit comprising an inverter compressor and a constant compressor, the second outdoor unit comprising a compressor, the number of compressors of the second outdoor unit being less than that of the first outdoor unit to generate a pressure difference between the heat exchanger of the first outdoor unit and the heat exchanger of the second outdoor unit, the pressure difference being compensated by the pressure regulating tube.  
   
   
       7 . A method for controlling an air conditioner, comprising the steps of: 
 determining if a compressor is driven for more than a predetermined time;    measuring a discharge temperature of the compressor when the compressor is driven for more than the predetermined time;    comparing the measured temperature with a predetermined temperature; and    controlling an opening of an electronic expansion valve is performed to be higher than a current super heating when the refrigerant in the compressor is in a liquid state.    
   
   
       8 . The method according to  claim 7 , wherein, when the measured temperature is lower than the predetermined temperature, the opening of the electronic expansion valve is controlled such that the discharge temperature can be increased to be higher than the current super heating by a predetermined level.  
   
   
       9 . The method according to  claim 7 , further comprising the step of determining if the discharge temperature is increased by a predetermined level after controlling the opening of the electronic expansion valve.  
   
   
       10 . The method according to  claim 9 , further comprising the step of returning to a former super heating state when the discharge temperature is increased by the predetermined level.  
   
   
       11 . A method for controlling an air conditioner, comprising the steps of: 
 determining if a compressor is driven for more than a predetermined time;    measuring a discharge temperature of the compressor when the compressor is driven for more than the predetermined time;    comparing the measured temperature with a temperature predetermined according to an outdoor temperature; and    controlling an opening of an electronic expansion valve is performed to be higher than a current super heating when the measured temperature is lower than the predetermined temperature.    
   
   
       12 . The method according to  claim 11 , wherein, when the measured temperature is lower than the predetermined temperature, the opening of the electronic expansion valve is controlled such that the discharge temperature can be increased to be higher than the current super heating by a predetermined level.  
   
   
       13 . The method according to  claim 11 , further comprising the step of determining if the discharge temperature is increased by a predetermined level after controlling the opening of the electronic expansion valve.  
   
   
       14 . The method according to  claim 11 , further comprising the step of returning to a former super heating state when the discharge temperature is increased by the predetermined level.  
   
   
       15 . A method for controlling an air conditioner, comprising the steps of: 
 determining if a compressor is driven for more than a predetermined time;    measuring a discharge temperature of the compressor when the compressor is driven for more than the predetermined time;    comparing the measured temperature with a temperature predetermined according to a vaporizing temperature; and    controlling an opening of an electronic expansion valve is performed to be higher than a current super heating when the measured temperature is lower than the predetermined temperature.    
   
   
       16 . The method according to  claim 15 , wherein, when the measured temperature is lower than the predetermined temperature, the opening of the electronic expansion valve is controlled such that the discharge temperature can be increased to be higher than the current super heating by a predetermined level.  
   
   
       17 . The method according to  claim 15 , further comprising the step of determining if the discharge temperature is increased by a predetermined level after controlling the opening of the electronic expansion valve.  
   
   
       18 . The method according to  claim 15 , further comprising the step of returning to a former super heating state when the discharge temperature is increased by the predetermined level.  
   
   
       19 . A method for controlling an air conditioner, comprising the steps of: 
 driving a first compressor;    determining if the first compressor is driven for more than a predetermined time;    measuring a discharge temperature of the first compressor when the first compressor is driven for more than the predetermined time;    comparing the measured temperature with a predetermined temperature;    replacing the first compressor with a second compressor when the measured temperature is lower than the predetermined temperature; and    vaporizing liquid refrigerant in the first compressor by pre-heating in the first compressor.    
   
   
       20 . The method according to  claim 19 , further comprising the step of determining if a pre-heating time is above a predetermined time.  
   
   
       21 . The method according to  claim 20 , further comprising the step of operating again the first compressor to compress the refrigerant when the pre-heating time is above the predetermined time.  
   
   
       22 . The method according to  claim 21 , further comprising the step of displaying a malfunction state of the first compressor when a liquid compression state is maintained even when the first compressor is operated again.