Air conditioner

Abstract

An air includes: a compressor for compressing a refrigerant; an indoor heat exchanger for cooling or heating indoor with a refrigerant; an outdoor heat exchanger for exchanging heat of a refrigerant and outdoor air; an outdoor fan for ventilating outdoor air with the outdoor heat exchanger; a cooling/heating switching valve for switching cooling/heating; a first expansion device installed between the indoor heat exchanger and the outdoor heat exchanger; a CNT heater module installed between the outdoor heat exchanger and the cooling/heating switching valve to evaporate a refrigerant; a second expansion device installed between the outdoor heat exchanger and the CNT heater module; and a controller for sustaining a heating mode of the cooling/heating switching valve.

1 . An air conditioner comprising:
 a compressor for compressing a refrigerant;   an indoor heat exchanger for cooling or heating indoor with a refrigerant;   an outdoor heat exchanger for exchanging heat of a refrigerant and outdoor air;   an outdoor fan for ventilating outdoor air to the outdoor heat exchanger;   a cooling/heating switching valve for switching cooling/heating;   a first expansion device installed between the indoor heat exchanger and the outdoor heat exchanger;   a CNT heater module installed between the outdoor heat exchanger and the cooling/heating switching valve to evaporate a refrigerant;   a second expansion device installed between the outdoor heat exchanger and the CNT heater module; and   a controller for sustaining, when performing a heating operation, if a defrost condition becomes, a heating mode of the cooling/heating switching valve, fully opening the first expansion device, adjusting an opening degree so that the second expansion device expands a refrigerant, and performing a continuous heating defrost operation for operating the CNT heater module.   
     
     
         2 . The air conditioner of  claim 1 , further comprising a CNT heater module/second expansion device bypass flow path for connecting between the cooling/heating switching valve and the CNT heater module and between the outdoor heat exchanger and the second expansion device. 
     
     
         3 . The air conditioner of  claim 1 , further comprising a check valve installed in the CNT heater module/second expansion device bypass flow path to block a refrigerant not to flow from between the outdoor heat exchanger and the second expansion device to between the cooling/heating switching valve and the CNT heater module. 
     
     
         4 . The air conditioner of  claim 2 , further comprising a second expansion device bypass flow path for connecting between the second expansion device and the CNT heater module and the CNT heater module/the second expansion device bypass flow path. 
     
     
         5 . The air conditioner of  claim 4 , further comprising a check valve installed in the second expansion device bypass flow path to block a refrigerant not to flow from between the second expansion device and the CNT heater module to the second expansion device bypass flow path. 
     
     
         6 . The air conditioner of  claim 1 , wherein the defrost condition is a condition for allowing a piping temperature of the outdoor heat exchanger to a setting temperature or less while performing a heating operation. 
     
     
         7 . The air conditioner of  claim 1 , wherein the controller initializes the second expansion device to a defrost initial opening degree and adjusts an opening degree of the second expansion device under a defrost condition of the air conditioner. 
     
     
         8 . The air conditioner of  claim 1 , further comprising:
 a compressor inhalation temperature sensor for detecting an inhalation temperature of the compressor; and   a CNT heater module inlet temperature sensor for detecting an inlet temperature of the CNT heater module,   wherein the controller adjusts an opening degree of the second expansion device so that a difference between an inhalation temperature of the compressor and an inlet temperature of the CNT heater module reaches a target inhalation superheat temperature.   
     
     
         9 . The air conditioner of  claim 8 , wherein the controller adjusts an opening degree of the second expansion device at a second expansion device opening change setting time interval. 
     
     
         10 . The air conditioner of  claim 1 , further comprising a CNT heater module temperature sensor for detecting a temperature of the CNT heater module,
 wherein the CNT heater module includes a plurality of CNT heaters, and   the controller determines the turned-on number of the plurality of CNT heaters according to a temperature of the CNT heater module.   
     
     
         11 . The air conditioner of  claim 10 , wherein the controller determines the turned-on number of the plurality of CNT heaters at a CNT heater module change setting time interval.