Power‐to‐Liquids – Compensation of Varying E‐Fuel Compositions via Digital Rate Shaping

Authors

D. Neumann MSc, Prof. Dr.-Ing. S. Pischinger, M. Zubel MSc, Dipl.-Wirt.-Ing. B. Heuser, K. Thenert MSc, Prof. Dr. rer. nat. W. Leitner, RWTH Aachen University; Dr.-Ing. M. Schönen, Dr.-Ing. J. Schaub, Dipl.-Ing. C. Jörg, FEV Europe GmbH, Aachen

Year

2018

Print Info

Fortschritt-Berichte VDI, Series 12, No 807

Summary

Synthetic fuels, for example so-called E-Fuels, feature a substantial potential in solving the trade-offs between CO₂ and pollutant emissions of Diesel engines. Therefore, they provide a worthwhile solution for a clean and sustainable mobility.
The production of these fuels is essentially CO₂-neutral and allows the reduction of soot and NO_x emissions down to a level of close to zero, also under real driving conditions. Due to the different carbon sources and the fluctuating supply of regenerative electricity, the fuel production steps may differ, resulting in variations of the fuel composition and thus in the combustion properties. These variations are challenging, since they can result in significant deviations of the combustion behavior which typically cannot be taken into account during the engine calibration process. This serves as a motivation to develop self-adapting engine control structures that are capable of compensating these effects. The method applied during the investigations presented in this paper makes use of digital injection rate shaping. The generated injection profiles are automatically adapted online to meet the target combustion behavior and to ensure the desired emission and efficiency performance of the engine.
Different synthetic fuel compositions have been investigated at representative operation points in order to proof the controller’s ability to react properly on the various fuel characteristics. Also, EGR variations in the typical range of application have been performed to demonstrate the impact of the fuel composition on critical emissions like NOx and particulates. All investigations were conducted on a single cylinder research engine always in comparison to conventional petroleum based Diesel fuel. The combustion and emission performance of each fuel derivative are presented and discussed in this paper.
It has been shown that the fuels selected offer great potential for reducing pollutant emissions. A maximum reduction of the soot level down to only 4% of the Diesel fuel level was possible. In addition, the control concept was successfully demonstrated together with these fuels, which opens up new areas of application.