Comparison of Moving Boundary and Finite-Volume Heat Exchanger Models in the Modelica Language

Adriano Desideri, Bertrand Dechesne, Jorrit Wronski, Martijn van den Broek, Sergei Gusev, Vincent Lemort, Sylvain Quoilin
2016 Energies  
When modelling low capacity energy systems such as a small (5-150 kW el ) organic Rankine cycle unit, the governing dynamics are mainly concentrated in the heat exchangers. As a consequence, accuracy and simulation speed of the higher level system model mainly depend on the heat exchanger model formulation. In particular, the modelling of thermodynamic systems characterized by evaporation or condensation, requires heat exchanger models capable of handling phase transitions. To this aim, the
more » ... te volume (FV) and the moving boundary (MB) approaches are the most widely used. The two models are developed and included in the open-source ThermoCycle Modelica library. In this contribution a comparison between the two approaches is performed. Their performance is tested in terms of model integrity and accuracy during transient conditions. Furthermore the models are used to simulate the evaporator of an ORC system and their responses are validated against experimental data collected on an 11 kW el ORC power unit.
doi:10.3390/en9050339 fatcat:ycxrvkedwzdjjnnyssmqake73m