Thermodynamic study of engine waste heat recoveryapplying a dual-loop cycle and TEG

In this study, a dual-loop organic Rankine cycle was applied to recover the waste heat of anengine. The EES software was applied to perform the simulation. A parametric study was performedto study the effects of different parameters on the efficiency of the system. According to the results,the HT evaporator has the highest amount of exergy destruction rate, which is followed by the HTturbine and LT turbine. When the input pressure to the HT turbine rises, the amount of powerproduced in the low-temperature part and the thermal efficiency begins to rise but then remainsconstant and decreases slightly. But this increase in the input pressure to the turbine in the hightemperaturesection has an opposite effect on the production power and the thermal efficiency in thehigh-temperature section of the cycle and is decreasing. The exhaust gas temperature after recoverycauses a decrease in the amount of power produced in the LT cycle while increasing in the HT cycle.When the Tg value is increasing, the thermal efficiency of the LT cycle is constant, while anincreasing trend happens in the HT cycle. Finally, it is shown that by applying a TEG unit instead ofthe condenser of the LT cycle, ۳% more power can be produced by the system.

Keywords:

Waste heat recovery , Dula loop ORC cycle , Thermodynamic analysis , Working fluid