Refrigerating device and method for circulating a refrigerating fluid associated with it

A method for circulating a refrigerating fluid, the method comprising:

• compressing the refrigerating fluid in a main compressor;
• condensing the refrigerating fluid in a condenser downstream of and in fluid communication with said main compressor;
• expanding the refrigerating fluid in main expansion means downstream of said condenser;
• evaporating the refrigerating fluid in an evaporator downstream of and in fluid communication with said main expansion means;
• between said condensation stage and said expansion stage, having at least one heat exchange stage involving a heat exchange inside at least one heat exchanger,
• said heat exchange being between the refrigerating fluid downstream from the condenser and an associated amount of the refrigerating fluid downstream from the condenser,
• said refrigerating fluid, downstream from the condenser, circulating inside a hot branch of said at least one heat exchanger,
• said associated amount circulating inside a cold branch of said at least one heat exchanger, wherein said associated amount is bled-off from the refrigerating fluid downstream from the condenser and is cooled inside an expansion means before flowing downstream into said cold branch of said at least one heat exchanger;
• and
• between said main expansion stage and said main compression stage, having a pre-compression stage involving pre-compression of the refrigerating fluid inside a turbocompressor unit,
• said pre-compression stage comprising at least one expansion stage involving expansion of the associated amount inside at least one turbine portion of the turbocompressor unit, the associated amount leaving the cold branch of said at least one heat exchanger to flow into said at least one turbine.