Rheological properties of water-fuel emulsions produced by water injection into diesel fuel

The main energy means of mobile agricultural machinery are diesel engines, which consume a significant amount of fuel and are pollutants of the environment. To solve the problem, in the recent years, studies have been conducted on the possibility of using water-fuel emulsions (WFE) as fuel for diesel engines. The conducted studies of the use of WFE in marine diesel engines showed that WFE provides fuel savings of about 3%, reduces smoke, and makes it is possible to force the diesel engine, which is especially important for tractor diesels operating in unsteady modes. In addition, the use of WFE makes it possible to reduce deposits on the surfaces of the injector nozzle parts and improve environmental conditions at the work site. The advantage of using WFE is that it does not require structural changes to the engine and significant investments. The most important properties of WFE when used as fuel in diesel internal combustion engines (ICE), are the stability, rheological properties and sizes of water droplets, which ensure their passage through the micron gaps of precision interfaces of fuel equipment and the tendency to coagulation. Unfortunately, at present, the use of WFE is constrained not only by “hydrophobiaˮ, but also by the inability to control the quality of the prepared emulsion, which is determined by a large number of factors. The main ones are: the mass fraction of water in the emulsion W, the dispersion of the emulsion (the average size of water particles dk) and the uniformity of the distribution of water particles over the fuel volume and temperature. These factors determine the rheological properties of WFE (viscosity, density, interfacial tension, flash point, pour point, corrosion activity, and others). The lack of data on the influence of WFE preparation modes does not allow us to reasonably choose the parameters that ensure the production of an emulsion of the required quality. The purpose of the article is to study the rheological properties of fuel emulsions obtained by injecting water into diesel fuel.