Implementation of electronic throttle for control of a dual fuel diesel engine

Abstract

Dual fuel diesel engines can provide lower emissions as well as allow a diversified fuel supply. Dual fueling of diesel engines is typically accomplished using a gaseous fuel in the intake manifold and a quantity of pilot diesel directly injected into the cylinder to initiate combustion. However low load dual fuelling typically leads to a higher unburnt hydrocarbon component. Large engines for heavy machinery and marine applications will continue to be required and thus research on their use instigated this research to mitigate the undesirable unburnt hydrocarbon at part load. An electronic throttle body was implemented in the intake of a two-liter common rail diesel engine that had been converted to dual fuel operation. The throttle body was used to reduce the quantity of air admitted into the engine and thus a lower air-to-fuel ratio (i.e. closer to stochiometric). This was achieved with the aim of achieving better combustion in the end gas region and thus lower unburnt hydrocarbons. A low cost MQ8 hydrocarbon sensor was used to measure the unburnt hydrocarbons in the exhaust.