Waste Heat Recovery from Exhaust and Coolant of OM 352 Diesel Engine Using a Transcritical Dual Loop Organic Rankine Cycle

A thermodynamic analysis is reported for Waste Heat Recovery (WHR) from exhaust gas and coolant of OM 352 Diesel engine using a transcritical dual loop Organic Rankine Cycle (ORC). To reach the best results, various working fluids are examined in the cycle. Also, a parametric study is performed to reveal the effects on system performance of lower pressure of high temperature loop. Results show that the dual cycle with toluene in high temperature loop and R143a in low temperature loop has the best performance so that employing the dual cycle increases the system produced power by 25%. The dual cycle energy and exergy efficiencies are calculated to be 20.63% and 55.86%, respectively. Also, the parametric study shows that the cycle produced power has a maximum value with respect to lower pressure of the high temperature loop.