Feasibility Study of Using LPG/DME Blended Fuel in Spark Ignition Engine and Compression Ignition Engine

摘要

In this study, DME-blended LPG fuel was experimentally investigated in SI(spark ignition) and CI(compression ignition) engine. In particular, performance, emissions characteristics (including hydrocarbon, CO, and NOx emissions), and combustion stability of SI and CI engine fuelled with DME-blended LPG fuel were examined. For a spark ignition engine DME fuel was add to LPG fuel by 0-30 wt%. On the contrary, LPG fuel was blended to DME fuel by LPG 0-40 wt% for a CI engine. Chemical reactions between seal materials and the DME-blended LPG fuel were also tested through immersion and tensile stress tests to find the best materials with tolerance for both LPG and DME. Chemical analysis was conducted to find the main components of the residues from the immersion test. Results showed that stable engine operation was possible for a wide range of engine loads up to 20% of DME by mass in an SI engine. Further, we demonstrated that, up to 10% DME, output engine power was comparable to that of pure LPG fuel in an SI engine. And it appeared that another stable engine operation was possible for a wide range of engine loads up to 30% of LPG by mass in a CI engine. Considering the results of the engine power output and exhaust emissions, blended fuel up to 20% of DME by mass can be used as an alternative to LPG in an SI engine, and blended fuel up to 30% of LPG by mass can be used as an alternative to diesel in a CI engine. DMEblended LPG fuel is expected to have potential for enlarging the DME market.