MODELING THE PROCESSES OF FEEDING WATER-FUEL EMULSIONS IN MARINE DIESEL ENGINES

Abstract

The aim of the article is to develop proposals for modelling the processes of feeding water-fuel emulsions in marine diesel engines to improve their efficiency. This goal is achieved by analysing the peculiarities of diesel engine operation on water-fuel emulsions, as well as the processes of mixture formation and fuel supply when operating on water-fuel emulsions. It is established that at present, the introduction of water-fuel emulsions into operation in marine diesel engines is almost not being implemented. It is proved that the use of water-fuel emulsions significantly improves the performance of engines and is an alternative fuel, since it makes positive changes in the physical nature of the processes of fuel supply, mixture formation and combustion, as well as in the mechanism of wear and environmental impact. Of course, the use of water-fuel emulsions requires a certain change in fuel equipment and the introduction of a module for preparing the transit of water-fuel emulsions, which can complicate the installation of the engine. By studying the movement of a water-fuel emulsion in a discharge pipeline as a two-phase fluid, such physical and mechanical properties as density, compressibility, and sound propagation speed were determined. The most significant result is the obtained dependencies, which were presented in the article within the framework of modelling the processes of water-fuel emulsions supply in marine diesel engines. During the mathematical modelling, the dependencies describing the change in pressure and speed during fuel injection in several areas of marine diesel engines were obtained. This made it possible to identify several local and integral features of the process, including fuel volume, the proportion of the fuel supply cycle during needle seating, the angular position of the shaft, and the maximum fuel pressure in the pump cavity, at the injection valve, and at the injector. The use of water-fuel emulsions makes it possible to reduce the minimum stable speeds at load and idle, as well as to meet the requirements of DSTU, which significantly increases the efficiency of the marine diesel engine.