Particulate Size Distribution from Diesel–Dimethyl Ether Dual Fuel Premixed Compression Ignition Combustion Engine

Abstract

Particulate matter (PM) emission has been a concern in recent years because of its impact on the atmospheric environment and human health. Recently the dual-fuel premixed charge compression ignition (PCCI) combustion strategy has become a popular option of reducing PM emissions from compression-ignition engines. In the current paper, the variations of PM emissions from the diesel–dimethyl ether (DME) dual-fuel premixed charge compression ignition combustion engine are investigated under the various input DME energy ratios, diesel injection timings, speeds, and loads. An electrical low pressure impactor (ELPI) is used for characterizing the particle number/mass and size distribution. The particulate number and mass concentrations for DME-diesel dual-fuel premixed charge compression ignition operation are lower than those of conventional direct-injection compression ignition (DICI) operation and reduce with a rise of port DME ratio under all operating conditions because of oxygen content and no C-C bond in DME molecular. The injection timing and speed also influence the particulate number and mass concentrations from the DME-diesel PCCI engine. Moreover, the particulate number and mass concentrations increase significantly with an increase in load for both conventional diesel operation and DME-diesel dual-fuel PCCI operation.