| 摘要 |
PROBLEM TO BE SOLVED: To improve the capacity and COP by stably operating a freezing cycle, by performing the operation and control so that the pressure in a vapor-liquid separator part is not higher than a critical pressure. SOLUTION: A controller 70 determines whether the pressure at the vapor-liquid separator 50 position is the critical pressure or higher, based on one of the outlet pressure of an ejector 40, the inlet and outlet pressures of a low-pressure-side heat exchanger 30, the suction pressure of a compressor 10, the outside air temperature, and the inlet refrigerant temperature of the low-pressure-side heat exchanger 30. When it is determined that it is the critical pressure or higher, the control is performed so as to reduce the refrigerant flow jetted from a nozzle 41. Thus, the difference between the high pressure side and low pressure side of the heat pump cycle is enlarged, and the pressure at the vapor-liquid separator 50 position on the low pressure side becomes the critical pressure of the refrigerant or lower, and the state capable of performing the vapor-liquid separation can be kept. Therefore, the freezing cycle is stably operated and controlled so that the pressure in the vapor-liquid separator 50 part is not higher than the critical pressure, thereby improving the capacity and COP. COPYRIGHT: (C)2006,JPO&NCIPI
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