Abstract: A device according to the present invention comprises one or more compression units for compressing a cooling gas fluid, one or more condensers for cooling and condensing the cooling fluid, an expansion device and one or more evaporators for the evaporation of the expanded coolant, according to which the supply, adjustment and expansion device supplying the evaporator or evaporators is a device in which the supply, adjustment and expansion of the cooling fluid is carried out by a fixed injector nozzle and by an inlet device of varying section depending on the amount of liquid outflowing from the evaporator or evaporators.Preferably, the liquid from the evaporator or evaporators is introduced into a container in which it is collected, so that by sensing the liquid level by means of a probe the inlet device of varying section can be controlled.