JPS6470669A - Air conditioner - Google Patents

Abstract

PURPOSE: To shorten defrosting operation time while preventing the liquid back in heat pump type air conditioner by making the front and rear of a throttle device communicate through a second throttle device and a bypassing path with a bypass valve to allow bypassing during the defrosting. CONSTITUTION: In the defrosting operation, the operation of a compressor 11 is continued, a bypass valve 18 is opened while a four-way valve 12 closed and moreover, room and outdoor fans 21 and 22 are turned OFF to perform a defrosting operation. As a result, a refrigerant is circulated in the direction of the arrow as indicated by the chain line and flows to an outdoor side heat exchanger 13 from a high temperature/high pressure refrigerant gas four-way valve 12 from the compressor 11 to perform a defrosting. The refrigerant after the radiation of heat is liquefied, shunted to the flow to a throttle device 14 and to a bypassing path 17 having the bypass valve 18 and a throttle device 19 to be decompressed in the both and then, returned to the compressor 11 via a room side heat exchanger 15. Thus, a liquid refrigerant is increased by the quantity distributed to the bypass 17 to enhance the defrosting capacity thereby enabling shortening of the defrosting time.