Energy, Exergy, Economic and Environmental (4E) Analysis of a Heavy-Duty Diesel Engine WHR System

In the present investigation, the energy, exergy, economic and environmental (4E) characteristics of a waste heat recovery (WHR) system including a dual-loop Organic Rankine Cycle (ORC) and a heavy-duty diesel was investigated. The proposed system recovers the available waste heat of the engine exhaust gas, intake air, and the coolant. Central composite design (CCD) which is a standard technique of response surface methodology (RSM) was employed for the design of experiments (DoE). Parametric study of the output responses to the effective input parameters was performed. The results showed that increasing the amount of the engine variables led to a significant increase in power production and exergy destruction rate of the system and vice versa. The minimum amount of payback period (5.57 years) was observed in the high values of the engine parameters. The maximum output power of the WHR system was 330 kW, which was equal to 33% of the diesel engine brake power. The maximum value for the sustainability index was also observed at approximately 3.28.