Air conditioner

Abstract

The air conditioner includes: an outdoor unit that includes a compressor, an outdoor heat exchanger, and an outdoor expansion valve; an indoor unit that includes an indoor heat exchanger and an indoor expansion valve; a liquid pipe that connects the outdoor unit to the indoor unit; and a gas pipe that connects the outdoor unit to the indoor unit. One end of the outdoor heat exchanger is coupled to the liquid pipe through the outdoor expansion valve. One end of the indoor heat exchanger is coupled to the liquid pipe through the indoor expansion valve. When a predetermined period of time elapses after the compressor is shut down, the outdoor expansion valve and the indoor expansion valve both close.

1 . An air conditioner comprising:
 an outdoor unit that includes a compressor, an outdoor heat exchanger, and an outdoor expansion valve;   an indoor unit that includes an indoor heat exchanger and an indoor expansion valve;   a liquid pipe that connects the outdoor unit to the indoor unit; and   a gas pipe that connects the outdoor unit to the indoor unit;   wherein one end of the outdoor heat exchanger is coupled to the liquid pipe through the outdoor expansion valve;   wherein one end of the indoor heat exchanger is coupled to the liquid pipe through the indoor expansion valve; and   wherein, when a predetermined period of time elapses after the compressor is shut down, the outdoor expansion valve and the indoor expansion valve both close.   
     
     
         2 . An air conditioner comprising:
 an outdoor unit that includes a compressor, an outdoor heat exchanger, and an outdoor expansion valve;   an indoor unit that includes an indoor heat exchanger and an indoor expansion valve;   a cooling/heating switching unit that includes a high/low pressure gas pipe switching valve and a low pressure gas pipe switching valve;   a liquid pipe that connects the outdoor unit to the indoor unit;   a high/low pressure gas pipe that connects the outdoor unit to the high/low pressure gas pipe switching valve;   a low pressure gas pipe that connects the outdoor unit to the low pressure gas pipe switching valve; and   a gas pipe that connects the indoor unit to the cooling/heating switching unit;   wherein one end of the outdoor heat exchanger is coupled to the liquid pipe through the outdoor expansion valve;   wherein one end of the indoor heat exchanger is coupled to the liquid pipe through the indoor expansion valve; and   wherein, when a predetermined period of time elapses after the compressor is shut down, the outdoor expansion valve and the indoor expansion valve both close or the outdoor expansion valve, the high/low pressure gas pipe switching valve, and the low pressure gas pipe switching valve all close.   
     
     
         3 . An air conditioner comprising:
 an outdoor unit that includes a compressor, an outdoor heat exchanger, and an outdoor expansion valve;   an indoor unit that includes an indoor heat exchanger and an indoor expansion valve;   a cooling/heating switching unit that includes a gas-liquid separator, a high pressure pipe switching valve, a low pressure pipe switching valve, and a liquid pressure adjustment valve;   a high pressure pipe that couples the outdoor unit to the cooling/heating switching unit;   a low pressure pipe that couples the outdoor unit to the cooling/heating switching unit;   a gas pipe that couples the indoor unit to the cooling/heating switching unit; and   a liquid pipe that couples the indoor unit to the cooling/heating switching unit;   wherein one end of the outdoor heat exchanger is coupled to the high pressure pipe through the outdoor expansion valve;   wherein one end of the indoor heat exchanger is coupled to the liquid pipe through the indoor expansion valve; and   wherein, when a predetermined period of time elapses after the compressor is shut down, the outdoor expansion valve, the indoor expansion valve, the high pressure pipe switching valve, the low pressure pipe switching valve, and the liquid pressure adjustment valve all close.   
     
     
         4 . The air conditioner according to  claim 1 , wherein a predetermined valve closes when the liquid pressure in the liquid pipe is equal to or lower than a predetermined value. 
     
     
         5 . The air conditioner according to  claim 2 , wherein a predetermined valve closes when the liquid pressure in the liquid pipe is equal to or lower than a predetermined value. 
     
     
         6 . The air conditioner according to  claim 3 , wherein a predetermined valve closes when the liquid pressure in the liquid pipe is equal to or lower than a predetermined value. 
     
     
         7 . The air conditioner according to  claim 1 , wherein a predetermined valve closes when the liquid pipe is not liquid-sealed. 
     
     
         8 . The air conditioner according to  claim 2 , wherein a predetermined valve closes when the liquid pipe is not liquid-sealed. 
     
     
         9 . The air conditioner according to  claim 3 , wherein a predetermined valve closes when the liquid pipe is not liquid-sealed. 
     
     
         10 . The air conditioner according to  claim 1 , wherein, if the liquid pressure in the liquid pipe increases after a predetermined valve is closed, a certain valve opens. 
     
     
         11 . The air conditioner according to  claim 2 , wherein, if the liquid pressure in the liquid pipe increases after a predetermined valve is closed, a certain valve opens. 
     
     
         12 . The air conditioner according to  claim 3 , wherein, if the liquid pressure in the liquid pipe increases after a predetermined valve is closed, a certain valve opens. 
     
     
         13 . The air conditioner according to  claim 7 , wherein the liquid pressure in the liquid pipe is estimated based on an output from a temperature sensor installed in a refrigeration cycle process, a pressure sensor, or an outside air temperature sensor installed in the outdoor unit. 
     
     
         14 . The air conditioner according to  claim 8 , wherein the liquid pressure in the liquid pipe is estimated based on an output from a temperature sensor installed in a refrigeration cycle process, a pressure sensor, or an outside air temperature sensor installed in the outdoor unit. 
     
     
         15 . The air conditioner according to  claim 9 , wherein the liquid pressure in the liquid pipe is estimated based on an output from a temperature sensor installed in a refrigeration cycle process, a pressure sensor, or an outside air temperature sensor installed in the outdoor unit.