The invention relates to an assembly having a number of heat exchangers and to a method for evaporating a working medium by exchanging heat from a heat source medium, which assembly can be particularly advantageously used in combination with a system and a method for recovering energy from waste heat in a thermo-dynamic cycle process, wherein the waste heat is used as the heat source medium. In the assembly having a number of heat exchangers, each heat exchanger has a heat source medium through-passage and a working fluid chamber separated from said through-passage, and the heat source medium through-passages of the heat exchanger can be/are connected to one another in series in a ring assembly, wherein a respective valve means is provided between the heat source medium through-passages of two respective serially consecutive heat exchangers in the ring assembly, wherein a supply line for the heat source medium is provided which can be selectively connected to the inlet of the heat source medium through-passag
