A method of causing heat exchange between a first heat transfer fluid and a second heat transfer fluid in a heat exchange cell,
- the heat exchange cell including:
- a containment casing comprising a rear wall, a front wall and a peripheral side wall;
- a helically-shaped heat exchanger comprising at least one tubular duct for the flow of a first heat transfer fluid coiled about a longitudinal axis to define a helix, said heat exchanger being mounted in said containment casing,
- a feeding zone of a second heat transfer fluid, intended for the heat exchange with said first heat transfer fluid, defined in the casing coaxially and internally with respect to said helix,
- a first collection chamber of the second heat transfer fluid externally defined with respect to said heat exchanger between a radially outer wall of the heat exchanger and the peripheral side wall of the containment casing,
- a second collection chamber of the second heat transfer fluid at least partially delimited by at least one separating element mounted at an axially external position with respect to said heat exchanger,
- wherein the peripheral side wall of the casing encloses and laterally delimits the heat exchanger and the first collection chamber of the second heat transfer fluid substantially along the entire axial extension of the heat exchanger and the first collection chamber,
- wherein said first and second collection chambers of the second heat transfer fluid are separated from one another by said at least one separating element so as to define said second collection chamber between said at least one separating element, the peripheral side wall and the rear wall or the front wall of the containment casing,
- wherein said separating element comprises a heat exchange portion in contact with at least one portion of an end coil of the heat exchanger and configured to allow a heat exchange between at least one coil portion of the heat exchanger and the second heat transfer fluid flowing in said second collection chamber,
- the method comprising:
- feeding the second heat transfer fluid in said feeding zone;
- collecting the second heat transfer fluid in said first collection chamber;
- feeding the second heat transfer fluid from said first to said second collection chamber substantially in parallel to the peripheral side wall of the casing and in proximity thereto by means of at least one first passage formed between a peripheral edge of said at least one separating element and the peripheral side wall of the containment casing and/or in a peripheral area of said at least one separating element;
- carrying out a heat exchange between the second heat transfer fluid flowing in said second collection chamber and the first heat transfer fluid flowing in the end coil of the heat exchanger by means of said heat exchange portion of the separating element;
- and
- discharging the second heat transfer fluid from the second collection chamber along a direction substantially perpendicular to a longitudinal axis of the heat exchange cell by means of at least one second passage allowing a fluid outlet peripherally defined in said second collection chamber between an axial end of the peripheral side wall and the rear wall or the front wall of the containment casing.