Abstract
European Road traffic knows three major emission problems as follows: Particulate Matter- (PM) and nitrogen dioxide emissions (NO2) as well as carbon dioxide (CO2). Furthermore, a stable and secure supply of energy carriers is becoming more and more vital. An additional fact is that NO2 and PM air quality limits are frequently exceeded close to road-air-quality measurement sites. As a result, the European Union aims at raising shares of renewable and alternative energy carriers to 20%, which divides in 10% natural gas, 5% bio fuels and 5% hydrogen, by 2020.
CNG powered vehicles have proven their potential in mitigating current environmental threats in recent surveys. At the moment these positive effects on the environment can mainly be utilized in urban areas, as the operation range of the vehicles is currently limited to a maximum of about 300 km. To improve the customers´ acceptance of the vehicles, especially considering medium and long distances, an increase of the operation range is desirable.
Current limiting factors are dual fuel-operation, which demands a second fuel system for gasoline consisting of fuel pipes, a tank, a charcoal filter and a second fuel injection system. CNG tanks of steel which has influence on the total vehicles mass as well as axle mass distribution.
To reach the target of a vehicle, beating already existing CNG concepts in operation range, weight, cost, efficiency and thus customer acceptance, the overall concept of the CNG vehicle will be optimized in fuel consumption employing a software tool for drivetrain and overall vehicle lengthways-dynamics simulation. The CNG tank module utilizes modern lightweightcompound materials in connection with completely new developed integrated valves to allow the application of 30 MPa storage technologies. In addition to this increased storage density, innovative concepts like multi-vessel-management become applicable. The engine will be optimized for CNG combustion as it is used in the car as a pure monovalent concept without any additional fuel systems to exploit the full potential of the high octane number of CNG exceeding 120. The combination of these new technologies finally allows an increase of 100% in operation range up to 600 km and above at costs of a Diesel-powered concept and below.
This paper will give an overview of the new vehicle concept and first results, based on a detailed simulation model for vehicle, power train and driving cycle.
Keywords:Monovalent CNG-Vehicle, lightweight construction tank