Diesel engine fuel consumption and emission analysis using steam generated non-surfactant water-in-diesel emulsion fuel

Efforts in making water in diesel emulsion (W/D) with the absence of surfactant have been developed to address the issues of long-term stability and the dependence on surfactants. This paper discusses an alternative formation method of a non-surfactant W/D, e.g. by steam condensation. By injecting steam into a batch of colder diesel fuel, fine water droplets are formed and suspended in the fuel forming an emulsion. The droplets are confirmed to be in the size range of hundreds of nanometers. The emissions of NOx is reduced by a maximum of 71%, whereas the CO and UHC emissions are increased by maximum respectively 180% and a surprising 517%. Not less interesting is the lower BSFC which was measured at a maximum reduction of 18.4%. These results on emission analysis together with the brake specific fuel consumption confirm this method to resemble the combustion behaviour of a conventional emulsion fuel of lower NOx and BSFC, yet higher CO and UHC

Determining characteristics and engine emission of steam generated water-in-diesel emulsion fuel

Water-in-diesel emulsion fuel (W/D) is an effective method for reducing emission of nitrogen oxides (NOx) from a diesel engine. However, the current approach of producing W/D has its disadvantages in terms of cost and complexity. Therefore, a new approach to produce W/D is developed where water is introduced in vapour state, instead of as liquid, into the fuel. This new method may simplify the emulsion production process as it requires less mechanical parts than any previous non-surfactant emulsion forming methods. The objective of this study is to determine the physical characteristics of steam generated W/D and its engine emission. The characteristics to be determined include the size distribution of water droplets as well as water content. Engine emission will be measured from a 5 kW single cylinder, direct injected, air cooled diesel engine