|کد مقاله||کد نشریه||سال انتشار||مقاله انگلیسی||ترجمه فارسی||نسخه تمام متن|
|243458||501929||2013||11 صفحه PDF||سفارش دهید||دانلود رایگان|
Waste heat recovery by means of a Rankine Cycle is a promising approach for achieving significant reductions in fuel consumption and, as a result, exhaust emissions of passenger car engines. This approach is already well established in industrial applications such as gas and steam power plants or ship propulsion systems. While these systems are mainly designed for stationary operation, the behaviour in highly dynamic operating conditions becomes more important when the principle is transferred to a passenger car engine.Knowledge of the dynamic response of the employed heat exchangers plays an important role in performance prediction and control system design of the steam cycle. Hence, a dynamic model of the exhaust gas heat exchanger employing the moving-boundary principle was developed and is presented in this paper. The model describes both design operation and the heat-up procedure of the component. For achieving high model accuracy in the resulting broad range of operating conditions, new approaches for modelling wall temperature distribution and zone switching were developed.Simulations of stationary operating points as well as the response to typical disturbances of the system’s input variables are in good agreement with test bench measurements. The model is used to develop a control system for dynamic operation on the test bench. Further studies of the operating characteristics reveal varying dynamic behaviour depending on the heat flow rate from exhaust gas to working fluid as well as coupling of evaporation pressure and outlet steam temperature.
► A dynamic model of the evaporator in a passenger car waste heat recovery system based on the Rankine Cycle was developed.
► By using the moving-boundary approach and validating the model, high numerical efficiency and accuracy were achieved.
► A steam temperature control system was developed based on the model and implemented at the engine test bench.
► The dynamic operating characteristics of the evaporator were investigated based on measurements and simulations.
► Conclusions regarding system and control design for operation in highly dynamic driving conditions are presented.
Journal: Applied Energy - Volume 105, May 2013, Pages 293–303