Abstract
Waste heat recovery (WHR) technologies offer great opportunities for improving energy efficiency and
reducing CO2 emissions for energy intensive industrial processes. The DECAGONE project is
developing an innovative ORC-based WHR system to be demonstrated in an iron & steel plant located
in the Czech Republic. The design of the ORC system considers the practical site-specific conditions
and limitations, such as variations in heat source conditions, heat sink availability, and size and space
limitations for the ORC components. Various cycle configurations are compared with a thermodynamic
optimization model for maximizing the net power output subject to the process constraints, including
(1) recuperative vs. non-recuperative designs, (2) air vs. water as heat sink and (3) direct vs. indirect
evaporation. The recuperative cycle with indirect evaporation and direct air condensation is deemed the
most suitable solution for the project site conditions. The results provide recommendations for
performance improvement and indications for performance subject to practical plant operating
conditions, such as large range of temperature and flow rate of waste heat source. Analyses in this work
provide the basis for detailed component design and decision processes towards finalizing the design
of the demonstrator.
reducing CO2 emissions for energy intensive industrial processes. The DECAGONE project is
developing an innovative ORC-based WHR system to be demonstrated in an iron & steel plant located
in the Czech Republic. The design of the ORC system considers the practical site-specific conditions
and limitations, such as variations in heat source conditions, heat sink availability, and size and space
limitations for the ORC components. Various cycle configurations are compared with a thermodynamic
optimization model for maximizing the net power output subject to the process constraints, including
(1) recuperative vs. non-recuperative designs, (2) air vs. water as heat sink and (3) direct vs. indirect
evaporation. The recuperative cycle with indirect evaporation and direct air condensation is deemed the
most suitable solution for the project site conditions. The results provide recommendations for
performance improvement and indications for performance subject to practical plant operating
conditions, such as large range of temperature and flow rate of waste heat source. Analyses in this work
provide the basis for detailed component design and decision processes towards finalizing the design
of the demonstrator.
