Air conditioning system for vehicle and method for controlling same

Abstract

The present invention relates to an air conditioning system for a vehicle and a method for controlling the same and, more specifically, to an air conditioning system for a vehicle and a method for controlling the same in which an opening/closing valve and an expansion valve are installed on a branch line connecting a first air conditioning unit and a second air conditioning unit, the opening/closing valve is always open so as to always supply a refrigerant to the second air conditioning unit during a cooling mode, and the opening/closing valve is always closed so as to always block the refrigerant supply to the second air conditioning unit during a heating mode, such that the refrigerant flows into the branch line of the second air conditioning unit even during a single cooling mode, thereby solving the problem wherein the pressure of a compressor increases, oil is forcibly circulated through a notch of the expansion valve, thereby solving the problem wherein the oil circulation rate decreases, and the refrigerant supply to the second air conditioning unit is blocked during a dual heating mode, thereby solving the problem wherein the heating performance of an electric heating type heater decreases when the second air conditioning unit is operated.

Dependencies are inferred from the claim text.