Boyuan Fan

Study of Gasoline Engine Waste Heat Recovery by Organic Rankine Cycle

Energy saving and environment protection are two important issues that today’s automobile industry must emphasize. Lots of heat energy waste with the exhaust gas when the engine is running. If this part of waste heat can be recovered, the energy efficiency will be improved. Thus plenty of energy can be saved and the global warming also can be reduced. In this paper, the organic Rankine cycle whose working fluid was R245fa was studied. It was adopted to recover the gasoline engine waste heat. The mathematical model of the organic Rankine cycle was built up in Matlab to search the optimized working condition. The pinch analysis method was used to analyze the outlet temperature of the exhaust gas. The results indicate that organic Rankine cycle is a good way to recover the gasoline engine waste heat, especially in the high load conditions. The temperature of the exhaust gas can be apparently decreased.

Hardware-in-loop simulation of a common rail turbocharged diesel engine ECU

To verify the hardware and software performance of a common rail turbocharged diesel engine ECU, a simulator was built up based on dSPACE hardware boards. The interface between the simulator and the ECU was developed. The real-time simulation model of the common rail turbocharged diesel engine was setup up in enDyna and successfully downloaded to the simulator. The monitor interface was designed in ControlDesk environment. The ECU hardware performance verification and failure mode test were conduct. The software integration verification was also carried out. The results indicate that the ECU could operate very well under various working conditions.

Parametric Robust Stability Analysis of a PID Controller for Variable Nozzle Turbocharger

There are many uncertain errors during the A/D and the D/A processes, and also in the fixed-point calculation when proportional-integral-derivative (PID) controller was employed in the engine control module. These will cause the perturbations of the parameters of PID controller. The robust stability performance of PID controller should be taken into account. It must be guaranteed that the uncertainties of the coefficients of the plant and the controller will not result in the feedback system unstable. The PID controller for the boost pressure control of a turbocharged diesel engine was designed based on the identified third order plant model. The parameters stability space of the PID controller was analyzed according to Hurwitz stability criterion. Using nonlinear programming method, the radius of the maximum stability ball of the parameters of Kp, Ki and Kd, which was centered at the tuned values calculated according to ISTE criterion, was computed. The permitted maximum uncertainty of the coefficients of the plant model denoted by the infinite norm was also analyzed based on the Edge Theorem. The results indicate that the tuned PID controller has good time domain performance, at the same time, the robust stability could satisfy the requirements.