Experimental investigations of an automotive diesel engine fuelled with natural gas in dual fuel mode

Abstract

The compressed natural gas (CNG) is a viable alternative fuel for diesel engine use due to its good combustion properties and low carbon content. The general objective of the research is CNG use at the automotive diesel engine for improving of the energetic performance and decrease of the emissions level. By achieving these specific objectives, the paper brings an important contribution to solving pollution problems in large urban areas for diesel engines, the solution can be easily implemented on diesel engines in running, even on the old design which can be converted to fit the current rules of pollution. All investigations were conducted at engine operating regime of 55% load and 2000 rev/min. Following the analysis of all recorded data the proper quantity of CNG will be determined in order to have lower emissions level and better energetic performances. The specific energetic consumption is expected to decrease with more than 40%; at the highest substitution ratio the maximum in-cylinder pressure reaches values superior with more than 10% and the maximum pressure rise rate with over 20%; CO2 emission reaches 10% lower level. The CNG use at automotive diesel engine leads to the improvement of combustion process and engine energetic performance.