Patent ID: 9618237
Date: 2017-04-11
CPC Classifications: F25B

Claim:
1. An air conditioner comprising: a compressor to compress refrigerant; an outdoor heat exchanger to be disposed outdoors to allow the refrigerant to heat-exchange with outdoor air; an indoor heat exchanger to be disposed indoors to allow the refrigerant to heat-exchange with indoor air; a converting unit to direct the refrigerant discharged from the compressor to the outdoor heat exchanger in a cooling operation and to the indoor heat exchanger in a heating operation; an accumulator disposed between the converting unit and the compressor to separate gas-phase and liquid phase refrigerants; an injection module to expand and to vaporize a portion of refrigerant flowing from the indoor heat exchanger to the outdoor heat exchanger in the heating operation; a controller; a supercooling valve disposed between the injection module and the accumulator; and an injection valve disposed between the injection module and the compressor, wherein the injection module comprises: an injection expansion valve to expand the portion of refrigerant flowing therethrough; and an injection heat exchanger to supercool the rest of refrigerant by allowing the rest of refrigerant to heat-exchange with the portion of the refrigerant expanded by the injection expansion valve, wherein the controller is configured to: control the converting unit to direct the refrigerant discharged from the compressor to the indoor heat exchanger at a start of the heating operation, wherein the injection expansion valve, the supercooling valve and the injection valve are closed, open the supercooling valve and the injection expansion valve in a closed state of the injection valve to direct oil and condensed refrigerant remaining in the injection module to an accumulator through the supercooling valve, determine whether a predetermined time for discharging the oil and condensed refrigerant remaining in the injection module had passed, close the supercooling valve when the controller determines that the predetermined time had passed, and open the injection valve to direct the portion of the refrigerant vaporized by the injection module to the compressor through the injection valve.