CASCADE REFRIGERATING MACHINE Russian patent published in 2015 - IPC F25B7/00 

FIELD: heating.

SUBSTANCE: invention relates to refrigerating engineering. The cascade refrigerating machine contains in the lower branch of the cascade, installed in series the liquid separator separating the coolant flow into gas and liquid components, the preliminary recuperative heat exchanger, the main recuperative heat exchanger, the main throttling device, the evaporator, the compressor and the condenser. The first outlet of the liquid separator is connected to the coolant direct flow inlet to the preliminary recuperative heat exchanger, and the second outlet of the liquid separator is connected through the preliminary throttling device to the back flow inlet to the preliminary recuperative heat exchanger. The coolant flow outlet from the condenser and the inlet to the liquid separator are connected among themselves by the heat exchanger which is the aftercooling condenser for the lower branch of the cascade and the evaporator for the upper branch of the cascade. The upper branch of the cascade is a one-stage refrigerating machine with series connected the compressor, the condenser, the receiver, the throttling device, the evaporator.

EFFECT: this invention allows to increase thermodynamic efficiency of low-temperature refrigerating cycle during the work at the low temperature levels at the expense of its new organising.

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