Unit for recovering and converting thermal energy from the exhaust gases of an internal combustion engine of a vehicle

A unit (1, 1') for recovering and converting thermal energy from the exhaust gases of an internal combustion engine (14) of a vehicle comprises a heat exchanger (2, 2') to be traversed by exhaust gases flowing along a by-pass path (5,5') branching out from an exhaust gas main line (4) of said internal combustion engine (14) and valve means (12) for controlling the flow of the exhaust gases through said path, said valve means (12) being driven by an actuator device (12A). The by-pass path (5, 5') is a U-shaped path defined entirely within the heat exchanger (2, 2'), starting from an inlet section (6, 6') and ending at an outlet section of the heat exchanger, the inlet and outlet sections (7, 7') being located on a same side of the heat exchanger (2) and both opening on an interface conduit portion (3) interposed in said exhaust gas main line (4). heat exchanger (2, 2') comprises one or more layers of thermoelectric material connected by means of an electric line (48) to a DC/DC converter (47), said DC/DC converter being arranged for the connection (49) to a power supply of a vehicle on which said internal combustion engine (14) is installed.