Air conditioner

Abstract

An air conditioner is provided that injects a refrigerant into a compressor in a simple configuration by two steps. The air conditioner may include a compressor to compress a refrigerant; a condenser to condense the refrigerant compressed at the compressor; an evaporator to evaporate the refrigerant condensed at the condenser; and an injection module to separate the refrigerant flowing from the condenser to the evaporator into a vapor-phase refrigerant and liquid-phase refrigerant, expand the separated vapor-phase refrigerant, and inject the expanded vapor-phase refrigerant into the compressor, expand and evaporate a portion of the separated liquid-phase refrigerant and inject the expanded and evaporated liquid-phase refrigerant into the compressor.

What is claimed is: 
     
         1 . An air conditioner, comprising:
 a compressor to compress a refrigerant;   a condenser to condense the refrigerant compressed at the compressor;   an evaporator to evaporate the refrigerant condensed at the condenser; and   an injection module to separate the refrigerant flowing from the condenser to the evaporator into a vapor-phase refrigerant and a liquid-phase refrigerant, expand the separated vapor-phase refrigerant, and inject the expanded vapor-phase refrigerant into the compressor, expand and evaporate a portion of the separated liquid-phase refrigerant and inject the expanded and evaporated refrigerant into the compressor.   
     
     
         2 . The air conditioner according to  claim 1 , further comprising:
 a first main expansion valve, disposed between the condenser and the injection module, to expand the refrigerant; and   a second main expansion valve, disposed between the injection module and the evaporator, to expand the refrigerant.   
     
     
         3 . The air conditioner according to  claim 2 , wherein the first main expansion valve is controlled according to a discharge superheat, that is, a difference between a temperature of the refrigerant discharged from the compressor and a temperature of the refrigerant condensed at the condenser. 
     
     
         4 . The air conditioner according to  claim 3 , wherein the second main expansion valve is controlled according to a suction superheat, that is, a difference between a temperature of the refrigerant suctioned into the compressor and a temperature of the refrigerant evaporated at the evaporator. 
     
     
         5 . The air conditioner according to  claim 4 , further comprising:
 a discharge temperature that senses the temperature of the refrigerant discharged from the compressor;   a condensation temperature that senses the temperature of the refrigerant condensed at the condenser;   a suction temperature sensor that senses the temperature of the refrigerant suctioned into the compressor; and   an evaporation temperature sensor that senses the temperature of the refrigerant evaporated at the evaporator.   
     
     
         6 . The air conditioner according to  claim 1 , wherein the injection module comprises:
 an injection liquid-vapor separator that separates the refrigerant flowing from the condenser to the evaporator into the vapor-phase refrigerant and the liquid-phase refrigerant;   a first injection expansion valve, connected to the injection liquid-vapor separator and the compressor, to expand the vapor-phase refrigerant separated by the injection liquid-vapor separator;   a second injection expansion valve, connected to the injection liquid-vapor separator, to expand a portion of the liquid-phase refrigerant separated by the injection liquid-vapor separator; and   an injection heat exchanger, connected to the second injection expansion valve and the compressor and disposed at the injection liquid-vapor separator, to evaporate the portion of the liquid-phase refrigerant expanded at the second injection expansion valve.   
     
     
         7 . The air conditioner according to  claim 6 , further comprising:
 an injection expansion temperature sensor to measure a temperature of the refrigerant expanded at the second injection expansion valve; and   an injection evaporation temperature sensor to measure a temperature of the refrigerant evaporated at the injection heat exchanger.   
     
     
         8 . The air conditioner according to  claim 6 , wherein the first injection expansion valve is located between the injection liquid-separator and a high pressure side of the compressor, and wherein the injection heat exchanger is connected to a low pressure side of the compressor. 
     
     
         9 . The air conditioner according to  claim 1 , further comprising a controller that controls operation of the air conditioner. 
     
     
         10 . An air conditioner, comprising:
 a compressor to compress a refrigerant;   a condenser to condense the refrigerant compressed at the compressor;   an evaporator to evaporate the refrigerant condensed at the condenser;   an injection liquid-vapor separator, disposed between the condenser and the evaporator, to separate the refrigerant into a vapor-phase refrigerant and a liquid-phase refrigerant;   a first injection expansion valve, connected to the injection liquid-vapor separator and the compressor, to expand the vapor-phase refrigerant separated by the injection liquid-vapor separator;   a second injection expansion valve, connected to the injection liquid-vapor separator, to expand a portion of the liquid-phase refrigerant separated by the injection liquid-vapor separator; and   an injection heat exchanger, connected to the second injection expansion valve and compressor and disposed at the injection liquid-vapor separator, to evaporate the portion of the separated liquid-phase refrigerant expanded at the second injection expansion valve.   
     
     
         11 . The air conditioner according to  claim 10 , further comprising:
 an injection expansion temperature sensor to measure a temperature of the refrigerant expanded at the second injection expansion valve; and   an injection evaporation temperature sensor to measure a temperature of the refrigerant evaporated at the injection heat exchanger.   
     
     
         12 . The air conditioner according to  claim 10 , wherein the second injection expansion valve is controlled according to an injection superheat, that is, a difference between the temperature measured by the injection evaporation temperature sensor and the temperature measured by the injection expansion temperature sensor. 
     
     
         13 . The air conditioner according to  claim 10 , further comprising:
 a first main expansion valve, disposed between the condenser and the injection module, to expand the refrigerant; and   a second main expansion valve, disposed between the injection module and the evaporator, to expand the refrigerant.   
     
     
         14 . The air conditioner according to  claim 13 , wherein the first main expansion valve is controlled according to a discharge superheat, that is, a difference between a temperature of the refrigerant discharged from the compressor and a temperature of the refrigerant condensed at the condenser. 
     
     
         15 . The air conditioner according to  claim 14 , wherein the second main expansion valve is controlled according to a suction superheat, that is, a difference between a temperature of the refrigerant suctioned into the compressor and a temperature of the refrigerant evaporated at the evaporator. 
     
     
         16 . The air conditioner according to  claim 15 , further comprising:
 a discharge temperature that senses the temperature of the refrigerant discharged from the compressor;   a condensation temperature that senses the temperature of the refrigerant condensed at the condenser;   a suction temperature sensor that senses the temperature of the refrigerant suctioned into the compressor; and   an evaporation temperature sensor that senses the temperature of the refrigerant evaporated at the evaporator.   
     
     
         17 . The air conditioner according to  claim 9 , further comprising a controller that controls operation of the air conditioner. 
     
     
         18 . An air conditioner, comprising:
 a compressor to compress a refrigerant;   a condenser to condense the refrigerant compressed at the compressor;   an evaporator to evaporate the refrigerant condensed at the condenser;   an injection liquid-vapor separator, disposed between the condenser and the evaporator, to separate the refrigerant into a vapor-phase refrigerant and a liquid-phase refrigerant;   a first injection expansion valve, connected to the injection liquid-vapor separator and the compressor, to expand the vapor-phase refrigerant separated by the injection liquid-vapor separator;   a second injection expansion valve, connected to the injection liquid-vapor separator, to expand a portion of the liquid-phase refrigerant separated by the injection liquid-vapor separator; and   an injection heat exchanger, connected to the second injection expansion valve and compressor and disposed at the injection liquid-vapor separator, to evaporate the portion of the separated liquid-phase refrigerant expanded at the second injection expansion valve, wherein the first injection expansion valve is located between the injection liquid-separator and a high pressure side of the compressor, and wherein the injection heat exchanger is connected to a low pressure side of the compressor,   
     
     
         19 . The air conditioner according to  claim 18 , further comprising:
 an injection expansion temperature sensor to measure a temperature of the refrigerant expanded at the second injection expansion valve; and   an injection evaporation temperature sensor to measure a temperature of the refrigerant evaporated at the injection heat exchanger.   
     
     
         20 . The air conditioner according to  claim 19 , wherein the second injection expansion valve is controlled according to an injection superheat, that is, a difference between the temperature measured by the injection evaporation temperature sensor and the temperature measured by the injection expansion temperature sensor.