A system for utilizing waste heat of an internal combustion engine via the Clausius-Rankine cycle process is provided that includes a circuit with lines containing a working medium, an evaporator heat exchanger which serves for evaporating the liquid working medium using waste heat of the internal combustion engine and which has an inlet opening for conducting the working medium into a flow duct and an outlet opening for conducting the working medium out of the flow duct, and the flow duct is divided into a plurality of flow duct parts connected hydraulically in parallel, an expansion machine, a condenser for liquefying the vaporous working medium, a collecting and compensating vessel for the liquid working medium, it is sought to be able to change the working medium substantially completely from a liquid state of aggregation to a gaseous state of aggregation at an evaporator heat exchanger.