Evaluation of the Effects of Water Injection in a Single Cylinder CFR Cetane Engine

Water injection effects on combustion phenomena have been investigated for several years, from both a theoretical and experimental viewpoints due to the collaboration of AGIP PETROLI and ISAB ERG Refinery. In this paper the effects of water injection on diesel combustion are investigated and reported. Using single cylinder CFR engine Cetane (AGIP PRIOLO Engine 11361/1) cetane number (C.N.) and NOx emissions have been measured. Tests were performed according to ASTM Cetane Method (ASTM X2.7.4). Water was supplied by a continuous injection system. The engine was fed with a base diesel oil from DA1302 Refinery plant. The water to fuel mass ratio was varied in the range of 0 to 1.5. Apparent heat release and fuel mass burning rate analysis of the in-cylinder pressure data were carried out. The results of in-cylinder pressure data analysis have shown the effects of internal refrigeration on the compression work and on the combustion phenomena. The pollutant emissions measurements were performed by AGIP PETROLI Laboratory. NOx emissions reduction confirm the effectiveness of water injection in reducing the engine environmental impact. Results have shown that water injection really represent a new way to control NOx formation in Diesel Engine and to reduce compression work.