Thermo-economic analysis and optimization of ICE-ORC systems based on a splitter regulation

The traditional Organic Rankine Cycle (ORC) system recovering waste heat from Internal Combustion Engine (ICE) ignores the low-grade thermal energy of jacket cooling water. In this paper, a new ICE-ORC configuration is proposed to maximize the ORC net power output for different ICE rated power outputs. The comparative analysis between the ICE-ORC system based on a splitter regulation and two traditional ICE-ORCs is presented with ten different working fluids. The computational results demonstrate whether it is necessary to recover jacket cooling water waste heat with different working fluids, and cascade utilization of exhaust gas and jacket water waste heat by splitter regulation is validated with different Caterpillar series of ICE. Moreover, using pentane as working fluid has the best performance which ORC power output is 556 kW for all the three different ICE-ORC bottoming cycles and ten working fluids, and the ICE-ORC bottoming cycle efficiency is increased by 17% compared with single ICE generator set. This research provides information to increase the efficiency and power output of ICE-ORC configuration modification and determines the direction of further improvement.