Scope of the Project
A major challenge the fossil oil based individual mobility faces is their comparably low energetic efficiency and the associated greenhouse gas- and pollutant emissions. Albeit gasoline internal combustion engines for passenger cars achieve peak efficiencies of about 35%, the typical efficiency of a car driving in official cycles or in the real world is usually below 20%. The reason for this low overall efficiency is the sharp decrease of the engine's efficiency at part load conditions and the dissipation of kinetic energy during braking phases. In addition to the efficiency issue, combustion-borne pollutant emissions are still a problem in congested areas. The major internal combustion engine-borne pollutants are NOx (NO and NO2 whilst NO2 is more critical), unburned reactive or carcinogenic hydrocarbons, and particles.
The CLEVER project has the goal to contribute to possible solutions for both problems (greenhouse gas- and pollutant emissions). One important step is to focus on the alternative fuel methane. Methane is available from fossile sources (natural gas) or can be produced from biogenic sources and upgraded to natural gas quality. More information about methane can be found in the "Methane as a Vehicle Fuel" section. One major advantage of methane compared with diesel or gasoline fuels is its higher hydrogen content: Methane combustion generates about 25% less CO2 per amount of energy.
- The CLEVER technology will take use of the advantages of a downsized/turbocharged engine, escpecially because methane is a very knock resistant fuel
- A new air/methane mixture preparations system will be implemented
- An electric motor will be added to the powertrain which will ensure a good driveability (electric boost, turbo-lag compensation), the automatic start/stop of the internal combustion engine and the partial recuperation of the vehicle's kinetic energy during braking phases.
The project goals are a 40% reduction of CO2 emissions (compared to a conventional gasoline vehicle of the same performance) and the fulfilment of the Euro-5 emission standards. A Volkswagen Touran will be used as the project demonstrator vehicle.
Picture 1: engine calibration on the transient test bench
Picture 2: CNG vehicle on the chassis dynamometer