Особенности моделирования гидродинамических процессов топливоподачи при работе судового дизеля на водотопливной эмульсии

Abstract

The article presents the results of mathematical modeling of the fuel supply process of a marine diesel working on diesel fuel and water-fuel emulsion with a water content of 30% as an alternative fuel. There have been found the specific features of fuel supply and the influence of the alternative fuel on the injection characteristics of standard fuel supply equipment during operation in nominal and partial modes. In evaluating the quality of fuel equipment operation on a water-fuel emulsion there were taken into account the following facts: changing of the fuel supply characteristics; changing injection parameters; type of fuel spraying in the initial and final phases of injection and reduction of fuel proportion supplied during the needle landing period; greater stability of successive injection cycles by increasing the active stroke of the plunger by 25-30%; features of injection processes due to thermal explosion effect. The telegraph equation for the unsteady fuel motion in a high pressure pipeline is obtained. The operation parameters of a marine diesel engine 6CHSPN2A 18/22 (DRA-300) are considered in nominal mode according to the screw characteristic for diesel fuel and water-fuel emulsion: plunger stroke of the high-pressure fuel pump; maximum pressure of the steady state in the connecting pipe; average integral pressure of the steady state in the nozzle, which determines the quality of spraying, the speed of landing of the sprayer needle on the saddle; amount of fuel supplied during the needle landing period; cyclic fuel supply; duration of the main injection; stability criterion of fuel supply processes in successive cycles, etc. It has been inferred that water-fuel emulsions can take a separate place in the list of alternative fuels, which will contribute to improving the quality of traditional fuels, productive burnout of hydrocarbon, nitrogen-hydrogen mixture, spirit mixtures, etc. due to the rational introducing additives into fuel, increasing the reliability indicators of cylinder-piston parts, etc.