Air conditioner and method for controlling an air conditioner

Abstract

An air conditioner is provided that may include a defrosting bypass valve disposed at a defrosting bypass pipe having a first end connected to a middle point of the outdoor heat exchanger and a second end connected to an inlet pipe of a compressor, and a processor configured to open and close the defrosting bypass valve according to a temperature of a refrigerant in an outdoor heat exchanger. At a beginning of a defrosting operation, the processor may open the defrosting bypass valve to bypass a portion of the refrigerant in the outdoor heat exchanger to the inlet pipe of the compressor, and if the temperature of the refrigerant in the outdoor heat exchanger exceeds a predetermined temperature, the processor may close the defrosting bypass valve, thereby achieving defrosting performance at an early stage of the defrosting operation.

What is claimed is: 
     
         1 . An air conditioner, comprising:
 a compressor configured to compress a refrigerant;   an indoor heat exchanger in fluid communication with the compressor, and configured to perform heat exchange between the refrigerant and indoor air;   an outdoor heat exchanger in fluid communication with the compressor, and configured to perform heat exchange between the refrigerant and outside air;   an expansion device disposed in a pipe that connects the indoor heat exchanger and the outdoor heat exchanger and configured to expand the refrigerant;   a defrosting bypass pipe having a first end connected at a middle point of the outdoor heat exchanger, and a second end connected to an inlet pipe of the compressor;   a defrosting bypass valve disposed in the defrosting bypass pipe; and   a processor configured to open and close the defrosting bypass valve according to a temperature of the refrigerant in the outdoor heat exchanger.   
     
     
         2 . The air conditioner of  claim 1 , wherein the outdoor heat exchanger comprises:
 a first row in which a tube connected to a pipe connected to the compressor is disposed;   a third row in which a tube connected to a pipe connected to the expansion device is disposed; and   a second row, which is disposed between the first row and the third row and in which a tube connecting the tube in the first row and the tube in the third row is disposed, wherein the defrosting bypass pipe is connected to the tube disposed in the second row.   
     
     
         3 . The air conditioner of  claim 2 , wherein in the outdoor heat exchanger, a flow direction of the refrigerant in the first row is opposite to a flow direction of the refrigerant in the second row. 
     
     
         4 . The air conditioner of  claim 2 , wherein in the outdoor heat exchanger, a lower end of the second row communicates with the first row, and an upper end of the second row communicates with the third row. 
     
     
         5 . The air conditioner of  claim 1 , wherein in response to the temperature of the refrigerant in the outdoor heat exchanger being lower than a predetermined temperature, the processor opens the defrosting bypass valve, and in response to the temperature of the refrigerant in the outdoor heat exchanger being higher than or equal to the predetermined temperature, the processor closes the defrosting bypass valve. 
     
     
         6 . The air conditioner of  claim 1 , further comprising an accumulator disposed between the outdoor heat exchanger and the compressor, wherein the defrosting bypass pipe comprises:
 a common bypass pipe connected to the outdoor heat exchanger;   a first bypass pipe branched from the common bypass pipe and connected to the inlet pipe of the compressor; and   a second bypass pipe branched from the common bypass pipe and connected to an inlet pipe of the accumulator.   
     
     
         7 . The air conditioner of  claim 6 , wherein the defrosting bypass valve comprises:
 a first bypass valve disposed in the first bypass pipe; and   a second bypass valve disposed in the second bypass pipe.   
     
     
         8 . The air conditioner of  claim 7 , wherein based on the temperature of the refrigerant in the outdoor heat exchanger, the processor selectively opens and closes the first bypass valve or the second bypass valve. 
     
     
         9 . The air conditioner of  claim 7 , wherein in response to the temperature of the refrigerant in the outdoor heat exchanger being lower than a predetermined reference temperature, the processor opens the second bypass valve, and in response to the temperature of the refrigerant in the outdoor heat exchanger being higher than or equal to the predetermined reference temperature, the processor closes the second bypass valve. 
     
     
         10 . A method for controlling an air conditioner comprising a compressor, an outdoor heat exchanger, an expansion device, and an indoor heat exchanger, the method comprising:
 performing a high-speed defrosting operation of opening a defrosting bypass valve disposed at a defrosting bypass pipe having a first end connected to a middle point of the outdoor heat exchanger, and a second end connected to an inlet pipe of the compressor; and   in response to a temperature of a refrigerant in the outdoor heat exchanger being higher than or equal to a predetermined temperature, performing a normal defrosting operation of closing the defrosting bypass valve.   
     
     
         11 . The method of  claim 10 , wherein the defrosting bypass pipe comprises:
 a common bypass pipe connected to the outdoor heat exchanger;   a first bypass pipe including a first bypass valve, branched from the common bypass pipe, and connected to the inlet pipe of the compressor; and   a second bypass pipe including a second bypass valve, branched from the common bypass pipe, and connected to an inlet pipe of an accumulator, wherein the performing of the high-speed defrosting operation comprises selectively opening and closing the first bypass valve or the second bypass valve according to the temperature of the refrigerant in the outdoor heat exchanger.   
     
     
         12 . The method of  claim 11 , wherein the performing of the high-speed defrosting operation comprises, in response to the temperature of the refrigerant in the outdoor heat exchanger being lower than the predetermined reference temperature, opening the second bypass valve, and in response to the temperature of the refrigerant in the outdoor heat exchanger being higher than or equal to the predetermined reference temperature, closing the second bypass valve. 
     
     
         13 . An air conditioner, comprising:
 a compressor configured to compress a refrigerant;   an indoor heat exchanger in fluid communication with the compressor and configured to perform heat exchange between the refrigerant and indoor air;   an outdoor heat exchanger in fluid communication with the compressor and configured to perform heat exchange between the refrigerant and outside air;   an expansion valve disposed in a pipe that connects the indoor heat exchanger and the outdoor heat exchanger, and configured to expand the refrigerant;   a defrosting bypass pipe having a first end connected to a middle point of the outdoor heat exchanger, and a second end connected to an inlet pipe of the compressor; and   a defrosting bypass valve disposed at the defrosting bypass pipe.   
     
     
         14 . The air conditioner of  claim 13 , wherein the outdoor heat exchanger comprises:
 a first row in which a tube connected to a pipe connected to the compressor is disposed;   a third row in which a tube connected to a pipe connected to the expansion device is disposed; and   a second row, which is disposed between the first row and the third row and in which a tube connecting the tube in the first row and the tube in the third row is disposed, wherein the defrosting bypass pipe is connected to the tube disposed in the second row.   
     
     
         15 . The air conditioner of  claim 14 , wherein in the outdoor heat exchanger, a flow direction of the refrigerant in the first row is opposite to a flow direction of the refrigerant in the second row. 
     
     
         16 . The air conditioner of  claim 14 , wherein in the outdoor heat exchanger, a lower end of the second row communicates with the first row, and an upper end of the second row communicates with the third row. 
     
     
         17 . The air conditioner of  claim 13 , further comprising an accumulator disposed between the outdoor heat exchanger and the compressor, wherein the defrosting bypass pipe comprises:
 a common bypass pipe connected to the outdoor heat exchanger;   a first bypass pipe branched from the common bypass pipe and connected to the inlet pipe of the compressor; and   a second bypass pipe branched from the common bypass pipe and connected to an inlet pipe of the accumulator.   
     
     
         18 . The air conditioner of  claim 17 , wherein the defrosting bypass valve comprises:
 a first bypass valve disposed in the first bypass pipe; and   a second bypass valve disposed in the second bypass pipe.