New nozzle unlocks potential of alternative fuel injection
Diesel-powered heavy-duty vehicles are a significant source of air pollution. The European Commission is setting increasingly stringent emission standards (for example, EURO 5) in order to combat this problem. The task facing the automobile industry is to reduce these harmful emissions without compromising fuel efficiency. Delphi Diesel Systems and five other partners took up this challenge in the framework of a GROWTH Programme RTD project entitled HY-SPACE. They focussed on the potential of a special fuel injection system (FIS) known as Homogeneous charge compression ignition (HCCI). Ignition is initiated by extremely high pressures in HCCI engines rather than by spark in conventional internal combustion engines. The UK engineers determined the nozzle specifications for HCCI engines suitable for heavy-duty applications. Parameters such as pressure, flow, nozzle geometry (number and size of holes) and spray pattern were defined. An investigation of valve inflow and outflow was also carried out. The resulting design, which incorporates 24 injection holes, achieves the narrow cone-shaped spray pattern necessary for optimal performance while minimising emissions. The prototype also proved extremely durable during testing at pressures up to 2000 bar. The HY-SPACE consortium, which includes several auto manufacturers, will explore the possibility of integrating the new FIS technology into future vehicles. Delphi Diesel Systems is also planning to target the original equipment manufacturers (OEM) market.
