PURPOSE: To permit to distribute the flow of refrigerant uniformly and facilitate the setting of a balance among heat transfer pipes with a simple structure by a method wherein a predetermined pieces of the heat transfer pipes among the group of heat transfer pipe are provided with orifices at the inside of the opening ends thereof.
CONSTITUTION: Upon room heating operation, refrigerant, whose pressure is reduced by capillary tubes 20, becomes two phases of gas and liquid and is distributed into two directions at the part of a n inlet for an outdoor side heat exchanger 19 equipped with fins 12 by a branch tube 15. Orifices 14 are provided at a part whereat the figfigerant enters into heat transfer tubes 13 from the branch tube 15, therefore, the dynamic pressure of the refrigerant is converted into a static pressure at this part and the refrigerant tries to flow uniformly into two pieces of heat transfer tubes. The resistances of the orifices 14 are changed in respective heat transfer tubes 13, therefore, the difference of flow resistances of respective heat transfer tubes themselves are cancelled by these orifices. Thus, the refrigerant of two phases may be distributed uniformly to flow through respective heat transfer tubes.
ITO SHOTARO
YOKOYAMA SHOICHI
OBATA MAKOTO
