On this paper a test rig that focuses on the dynamic and transient behavior of an ORC system for waste heat recovery is presented. An experimental campaign is carried out in order to analyze the transient behavior of a single finned-tube evaporator under continuous and discrete fluctuations of the heat source. The experimental results show the dynamic response of a custom-made ORC evaporator to sinusoidal fluctuations and ramp changes of the heat source. Due to its large thermal inertia, the evaporator is able to dampen fluctuations of the heat source in the MHz range, in fact, effectively “filtering out” sinusoidal fluctuations with frequencies larger than at least 1.67 MHz. This large thermal inertia of the ORC evaporator is accomplished by means of a heat exchanger design where the fins have a significant mass. The study illustrates how the design of the evaporator can be an important aspect in ORC dynamic performance that is often taken for granted. This is critical for applications in which the variability of the heat source is inherent, such as waste heat recovery.     «

On this paper a test rig that focuses on the dynamic and transient behavior of an ORC system for waste heat recovery is presented. An experimental campaign is carried out in order to analyze the transient behavior of a single finned-tube evaporator under continuous and discrete fluctuations of the heat source. The experimental results show the dynamic response of a custom-made ORC evaporator to sinusoidal fluctuations and ramp changes of the heat source. Due to its large thermal inertia, the e...     »