Vapor compression refrigeration cycle device

A vapor compression refrigeration cycle device comprising:

• a main refrigerant circuit formed by sequentially connecting a compressor, a use-side heat exchanger, an intermediate heat exchanger, a first expansion device and a heat source-side heat exchanger to one another through a refrigerant pipe;
• a bypass refrigerant circuit which branches off from the refrigerant pipe between the use-side heat exchanger and the first expansion device, and which is formed such that the bypass refrigerant circuit is sequentially connected to middle of a compression stroke of each of the second expansion device, the intermediate heat exchanger and the compressor;
• and
• a control device for controlling valve opening degrees of the first expansion device and the second expansion device;
• wherein
• when discharge pressure of refrigerant discharged from the compressor is equal to or smaller than reference pressure, the control device controls the compressor such that number of rotations of the compressor is increased.

A vapor compression refrigeration cycle device comprising:

• a main refrigerant circuit formed by sequentially connecting a compressor, a use-side heat exchanger, an intermediate heat exchanger, a first expansion device and a heat source-side heat exchanger to one another through a refrigerant pipe;
• a bypass refrigerant circuit which branches off from the refrigerant pipe between the use-side heat exchanger and the first expansion device, and which is formed such that the bypass refrigerant circuit is sequentially connected to middle of a compression stroke of each of the second expansion device, the intermediate heat exchanger and the compressor;
• a control device for controlling valve opening degrees of the first expansion device and the second expansion device;
• and
• a before-heating temperature sensor for detecting use-side heat medium temperature at an entrance of the use-side heat exchanger;
• wherein
• when the use-side heat medium temperature detected by the before-heating temperature sensor is equal to or smaller than reference temperature, the control device controls the compressor such that number of rotations of the compressor is increased.