Abstract: A steam generator (1) is provided for a Rankine cycle, especially for a waste heat recovery device (37) of an internal combustion engine (36), and preferably in a motor vehicle. The steam generator includes: a heat exchanger channel (2), in which a heat exchanger (3) is arranged, and a bypass channel (4) for bypassing the heat exchanger channel (2). A heating fluid can flow through the heat exchanger channel (2) and bypass channel (4) during the operation of the steam generator (1). A medium to be evaporated can flow through the heat exchanger (3) during operation of the steam generator (1). A compact structural shape with high energy efficiency is achieved with the heat exchanger channel (2) enveloping the bypass channel (4).

Abstract: An active muffler (1) for an exhaust system (13) of an internal combustion engine is provided with a housing (2), which has an upper shell (3) as well as a lower shell (4) and which defines an inner space (5). A loudspeaker (6) is arranged in inner space (5). A sound conduction channel (10) acoustically connects a membrane (9) of loudspeaker (6) to a connecting branch (11). A low-cost design is obtained if sound conduction channel (10) is formed integrally in the lower shell (4).