Hybridization and Phlegmatization of the pHCCI Diesel Engine

The rules for emissions for road vehicles are becoming increasingly strict, which steadily raises the requirements for the operation of vehicles with purely conventional diesel engines. PHCCI diesel combustion can defuse the Soot/\(\text {NO}_x\) gap, but optimal operation is only guaranteed at a low indicated mean pressure and low gradients in torque demand. To extend the power range in which pHCCI operation is possible, the use of additional mild hybridization is advisable. The additional degree of freedom created by the use of an electric motor makes it possible both to shift the load point of the combustion engine into the partially homogeneous range and to reduce the torque gradient. In addition, there is the advantage of being able to recuperate kinetic energy from the vehicle. In the presented approach, the implementation of hybridization and phlegmatization, both simulative and experimental, is shown and the advantages of emission and consumption reduction are described in more detail. A vehicle simulation programmed in Simulink uses the selected operating strategy to calculate the torque and speed demand on the internal combustion engine, taking into account the use of electrical energy and the limits of the e-machine. The generated torque/speed curves enable the operation of an engine test bench with parallel emission and consumption measurements. The results of various WLTC measurements show the advantage and the associated savings potential for consumption and emissions.