| 摘要 |
A heat exchanger (4) for a gas boiler for producing hot water is provided with a casing (11) through which combustion fumes flow and which extends along an axis (A), and a pipe (12) along which water flows and which is arranged inside the casing (11) and extends along a curved longitudinal axis (C) coiled about the axis (A) so as to form a succession of turns (20); the pipe (12) has an outer surface (22) provided with a plurality of longitudinal grooves (42) essentially parallel to the longitudinal axis (C) of the pipe (12). Optionally, an inner surface (23) of the pipe (12), or one or more portions thereof, is also longitudinally grooved. |
