Untersuchung eines Ottomotors mit abgaskondensatgespeistem Wassereinspritzsystem

  • Investigation of a gasoline engine with exhaust gas condensate water injection system

Voßhall, Tobias; Pischinger, Stefan (Thesis advisor); Schmitz, Katharina (Thesis advisor)

Aachen : RWTH Aachen University (2022, 2023)
Dissertation / PhD Thesis

Dissertation, Rheinisch-Westfälische Technische Hochschule Aachen, 2022


The main part of this work is the investigation of exhaust gas condensate as a medium for injection in water injection systems for gasoline engines. First of all, concepts are developed which allow harvesting of exhaust gas condensate in the vehicle. After these concepts have been worked out, the most promising system will be selected and investigated by simulation. The target is to determine the possible amounts of condensate that can be harvested in the vehicle under different boundary conditions such as ambient temperature, vehicles, engine variants and driving cycles. In addition, control strategies will be developed to control the system, which can be used in a vehicle setup down the road. All simulations are validated by measurements on a test vehicle. Investigations on the engine test bench determine the influence of the injection of exhaust gas condensate on combustion and raw emissions. Furthermore, the separation rates of different exhaust gas condensate separators are investigated. Following the build of a demonstrator vehicle with an exhaust gas condensation system, separation efficiencies are investigated under various conditions. In addition, exhaust gas condensate samples are taken after the use of various fuels and driving cycles and analyzed with respect to electrical conductivity and pH. Different exhaust gas condensates from the vehicle and from engine dynamometer tests are examined with regard to chemical composition. Injection components that come into contact with exhaust condensate are evaluated for media compatibility with exhaust condensate, compared to demineralized water. Lubricity tests of condensates, fuels and demineralized water are performed and compared to predict possible wear on injection components. In addition, the behavior of exhaust gas condensate over time during storage will be determined with respect to electrical conductivity and pH. For use in the vehicle and possible compliance with future standards, treatment options for exhaust gas condensate are being investigated in order to lower the electrical conductivity and reduce it to the level of demineralized water.


  • Chair of Themordynamics of Mobile Energy Conversion [412310]
  • Chair and Institute for Fluid Power Drives and Systems [412810]