Charge-sensitive modelling of organic Rankine cycle power systems for off-design performance simulation

This paper focuses on a charge-sensitive model to characterize the off-design performance of low-capacity organic Rankine cycle (ORC) power systems. The goal is to develop a reliable steady-state model that only uses the system boundary conditions (i.e. the supply heat source/heat sink conditions, the mechanical components rotational speeds, the ambient temperature and the total charge of working fluid) in order to predict the ORC performance. To this end, sub-models are developed to simulate each component and they are assembled to model the entire closed-loop system. A dedicated solver architecture is proposed to ensure high-robustness for charge-sensitive simulations.