Dynamic Response Performance Comparison of Ranking Cycles with Different Working Fluids for Waste Heat Recovery of Internal Combustion Engines

ORC (Organic Ranking Cycle) including RC (Ranking Cycle) is regarded as a suitable way of waste heat recovery for internal combustion engines. The working condition of the engine often changes, so the ORC or RC waste heat recovery system also works at different working conditions frequently and thus it is very meaningful to research the system dynamic response performance and control strategy. There are lots of organic working fluids and the systems with different working fluids have different dynamic response performance. In this study, the dynamic math model of four ORCs with different working fluids and RC as waste heat recovery system of a nature gas engine are established with Simulink. Based on this, their dynamic response performance is compared and analyzed, finding that the faster the system responds, the greater the mass flow rate of working fluid is, which provides useful reference for the control design of ORC with different working fluids.