Thermodynamic Analysis of ORC Configurations Used for WHR from a Turbocharged Diesel Engine

This paper illustrates a comparison between different solutions for waste heat recovery from a specific internal combustion engine using an Organic Rankine Cycle (ORC). The purpose of the present work is to find the cycle configuration and the fluid that can provide the maximum mechanical power for given conditions of waste heat recovery (WHR) from flue gas and motor cooling water of a Turbocharged Diesel Engine Electric Generator. The thermodynamic analysis is conducted for ten working fluids from different chemical classes: hydrofluorocarbons (HFC) and the new subclass hydrofluoroolefins (HFO), hydrocarbons (HC), siloxanes and alcohols applied on six ORC configurations, three conventional ones (basic ORC, regenerative ORC and preheater ORC), a regenerative dual-loop ORC (DORC), a mixture of two traditional ORC (one used for WHR from the motor cooling water and the other used for flue gas WHR) and a dual ORC but with a common condenser configuration. One of the working fluids investigated is a new HFO, named R1336mzz, which has very low GWP, zero ODP and good safety properties. This novel fluid also shows good results in our investigation. Future work and development perspectives are discussed.