Process for the Fast Ashing of DPF, DOC and SCR by Engine Oil

Numerous processes for the fast ashing of particulate filters are known from the literature. However, it is largely unknown how these processes behave among themselves and which of these processes results in the most realistic ash. As the influencing factors on ash production have not been yet fully clarified either, an FVV research project generated ash deposits on a particulate filter in a defined cycle from various operating points. The first ashing process was carried out without measures for the increased introduction of ash with a low SAPS oil. The ashing cycle was performed in such a way that the particulate filter could be regenerated exclusively continuously. The ash produced served as a reference and was compared with that from four other ashing processes: with an increased sulphate ash content in the engine oil, burner-supported ash input, oil injection into the intake manifold and fuel doping. The fast ashing process was performed in the same cycle and with the same engine as in the reference process. The ash produced in the individual processes was summarised in an evaluation matrix with regard to the deposition location, the ash morphology and composition, the recovery rate, the differential pressure and the maximum acceleration factor achieved. The process with the most promising approach was the generation of ash using a burner such as those used in household heating systems.

This project was a preliminary project in advance of more detailed studies of particulate filters by a cluster of five research institutes. In addition to the generation of real ash and the study of its deposition behaviour, the aim in future will be to develop an ash substitute and to carry out studies on the wall flow filter on the basis of a numerical model. As well as the closed filters, open-pore filters with ceramic and metallic carrier structures and their use on a large-bore engine will be validated.

Research Institute: Institute of Internal Combustion Engines (IVB), TU Braunschweig

Project Chairman: Dr. Bernhard Lüers, FEV GmbH

figure 1

Ash layer thickness of burner genereated ash: thin layer cenosphere

© Institute for Materials at TU Braunschweig

Optimisation of the Dynamic Behaviour of Highly Boosted Spark-ignition Engines

According to the current state of technology, the representation of the transient operating behaviour of turbocharged spark-ignition engines in process simulation is a major challenge. This is due to the complex interaction between the turbocharger and the internal combustion engine. In particular, modelling of the exhaust gas turbocharger results in a lack of definition in the simulation of the complete system. Within the framework of an IGF project funded by the German Federal Ministry of Economic Affairs and Energy (BMWi), an extended model was developed which improves on the standard model by processing the operating maps measured on the combustion chamber test stand and by the explicit modelling of the thermal behaviour on the basis of a heat flow model. The model development was based on extensive combustion chamber measurements as well as engine test bench tests of different hardware designs of the turbocharger module. The influence of the thermal condition of the exhaust manifold and the turbocharging module on the engine’s response behaviour was also examined on the engine test bench. Various modelling depths were compared with each other and their quality was evaluated in transient partial and full load and during load changes. With the final model, a significant improvement in the prediction of the turbine exit temperature was proven under steady-state and transient conditions. Furthermore, a significant improvement in the prediction of the engine response after a load requirement was achieved.

Research Institute: Institute for Internal Combustion Engines and Automotive Engineering (IVK) at the Chair in Automotive Powertrains, University of Stuttgart and the Institute for Combustion Engines (VKA), RWTH Aachen University

Project Chairman: Dipl.-Ing. Marc Sens, IAV GmbH