BMW Water Injection: Initial Experience and Future Potentials.

Authors

Dr.-Ing. B. Durst, Dr. techn. C. Landerl, Dipl.-Ing. J. Poggel, Prof. Dr.-Ing. C. Schwarz, Dr.-Ing. W. Kleczka, Dr.-Ing. B. Hußmann, BMW Group, Munich

Year

2017

Print Info

Fortschritt-Berichte VDI, Series 12, No 802

Summary

Further increases in specific power and torque requirements on current and future gasoline engines as well as significantly tighter regulations governing statutory emissions requirements are making it necessary to develop measures to reduce specific fuel consumption and to extend the engine map regions with stoichiometric operation. At BMW AG, various solutions for implementing water injection have been analyzed in terms of operating principle and efficiency, ranging from continuous plenum chamber injection into the intake manifold through to injecting a fuel/water mixture through the high-pressure gasoline injector. Several vehicles have been set up with these solutions; extensive endurance testing has confirmed the potential and the durability of the systems. In the form of the BMW M4 GTS, BMW M GmbH offers a series production vehicle powered by a turbocharged inline six-cylinder gasoline engine with water injection for increasing specific power. Experience gained when operating this system on the road and on racetracks has confirmed the system's robustness – customer feedback on it has been highly positive throughout. Subsequently, a holistic and systematic outlook of future applications in BMW vehicles is provided – extending from simple replenishment to storage solutions with onboard water recovery from exhaust gas or condensate from the air conditioning unit. At the same time, aspects of system availability during operation in cold surroundings are dealt with, with efficient thawing strategies and possibilities for bio-decontamination of the water in order to demonstrate the global applicability of the system.