Increasing waste heat recovery from an internal combustion engine by a dual-loop non-organic Rankine Cycle

This research proposes the combination of a dual-loop non-organic Rankine cycle (DNORC) with an internal combustion engine to increase the output power of the recovery system by focusing on the increase in the energy input and system efficiency. In doing so, it investigates the strategy of increasing the mean effective temperature of heat addition in the high-temperature Rankine cycle (HTRC) (to improve the system efficiency and the strategy of increasing the waste heat entering the low-temperature Rankine cycle (LTRC) (to increase the energy input. In this recovery system, by focusing on the recovery of the waste heat from the engine cooling system and exhaust, the radiator can be removed from the engine cooling system, and by mounting fewer parts on the engine, not only can extra power be generated but also the engine can be cooled down faster and more efficiently. By using a thermodynamic analysis, the appropriate matching conditions between the DNORC with the engine are determined. The results showed that as the input energy increased, the recovery rate and system efficiency also increased. The output power of the recovery system exceeded 20kW and the efficiency of the whole engine and the recovery system increased to 33%.