| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an air conditioning device for vehicle equipped with a two-stage compression type compressor which operates using one-stage expansion cycle during cooling and stops or bypasses a low-pressure cylinder and operates using only a high-pressure cylinder during a low-speed rotation. <P>SOLUTION: A heat pump system, which is operated by a compressor (20) having a low-pressure compression mechanism (7) and a high-pressure compression mechanism (9), includes a refrigerant circuit which configures a two-stage compression refrigeration cycle to allow an intermediate-pressure refrigerant to flow into the compressor (20) during heating and establishes a refrigeration cycle operative in one-stage compression/one-stage expansion mode during cooling. During cooling, the refrigerant is compressed by only the high-pressure compression mechanism (9) within a range in which a rotational speed (n) of an electric motor (5) driving the compressor (20) is equal to or smaller than a predetermined value and motor efficiency is poor, but the refrigerant is compressed by both of the low-pressure compression mechanism (7) and the high-pressure compression mechanism (9) within a range in which the rotational speed (n) is greater than the predetermined value. <P>COPYRIGHT: (C)2013,JPO&INPIT |
