This paper presents the identification and validation of a
dynamic Waste Heat Recovery (WHR) system model. Driven by upcoming
CO₂ emission targets and increasing fuel costs, engine exhaust gas
heat utilization has recently attracted much attention to improve
fuel efficiency, especially for heavy-duty automotive
applications.
In this study, we focus on a Euro-VI heavy-duty diesel engine,
which is equipped with a Waste Heat Recovery system based on an
Organic Rankine Cycle. The applied model, which combines first
principle modeling with stationary component models, covers the
two-phase flow behavior and the effect of control inputs.
Furthermore, it describes the interaction with the engine on both
gas and drivetrain side.
Using engine dynamometer measurements, an optimal fit of unknown
model parameters is determined for stationary operating points.
From model validation, it is concluded that the identified model
shows good accuracy in steady-state and can reasonably capture the
most important dynamics over a wide range of operating conditions.
The resulting real-time model is suitable for model-based
control.