Air conditioner and control system therefor

Abstract

An air conditioner includes: a compressor configured to compress a refrigerant; an outside heat exchanger configured to make the compressed refrigerant radiate heat; a pressure reducing unit configured to reduce the pressure of the heat-radiated refrigerant; an inside heat exchanger configured to vaporize the pressure-reduced refrigerant; a discharge pressure detector configured to detect a discharge pressure of the refrigerant discharged from the compressor; a controller configured to provide a duty factor according to the detected discharge pressure; and a control valve configured to adjust a discharge capacity of the compressor according to the provided duty factor. During a start-up operation of the compressor, the controller controls the duty factor provided to the control valve so that the discharge pressure detected by the discharge pressure detector is maintained within a predetermined range and so that the duty factor reaches a maximum system duty factor.

1 . An air conditioner comprising: 
 a compressor configured to compress a refrigerant;    an outside heat exchanger configured to exchange heat of the compressed refrigerant;    a pressure reducing unit configured to reduce the pressure of the heat-exchanged refrigerant;    an inside heat exchanger configured to vaporize the reduced pressure refrigerant;    a discharge pressure detector configured to detect a discharge pressure of the refrigerant discharged from the compressor;    a controller configured to set a duty factor in accordance with the detected discharge pressure; and    a control valve configured to adjust a discharge capacity of the compressor in accordance with the duty factor,    the controller controlling, during a start-up operation of the compressor, the duty factor provided to the control valve so that the discharge pressure detected by the discharge pressure detector is maintained within a predetermined range and so that the duty factor goes to a maximum system duty factor.    
   
   
       2 . The air conditioner of  claim 1 , wherein: 
 during the start-up operation of the compressor, the controller increases the duty factor at a predetermined rate when the detected discharge pressure from the discharge pressure detector is less than a first set value and decreases the duty factor at a predetermined rate when the detected discharge pressure is equal to or greater than a second set value that is greater than the first set value.    
   
   
       3 . The air conditioner of  claim 2 , wherein: 
 during the start-up operation of the compressor, the controller maintains the duty factor provided to the control valve when the detected discharge pressure from the discharge pressure detector is equal to or greater than the first set value and less than the second set value.    
   
   
       4 . The air conditioner of  claim 1 , wherein: 
 the air conditioner is a vehicle air conditioner installed in a vehicle ( 1 ); and    the compressor is driven by an engine of the vehicle ( 1 ).    
   
   
       5 . A controller for controlling a control valve that adjusts a degree of opening of a pressure introducing path connecting a discharge chamber and crankcase of a compressor to each other, the controller configured to: 
 provide a control signal to the control valve, the control signal representing a duty factor that determines the degree of opening of the pressure introducing path; and    provide the control signal, during a start-up operation of the compressor, to attain a maximum system duty factor and maintain a discharge pressure of a refrigerant discharged from the compressor within a predetermined range.