Numerical Study On The Electrostatic Atomization Process Of Liquid Fuel Based On The Principle Of Stability Region

As the energy source, liquid fossil fuels are the most commonly used in some burners. Atomization of liquid fuel will affects its efficiency directly, and even lead to the pipe bombing due to hot spots on the pipe. Furthermore, unburned fuel falling in ash bucket may form flammable vapor cloud, which may cause explosion. Obviously, it is important to increase liquid fuel atomization in improving the combustion efficiency of the fuel, and the safety in the course of using the burner.Electrospray has rapidly developed in recent years, which is one of the important branches of electro-hydrodynamics. In the electrostatic atomization process, liquid is charged in an electric field, and then the droplets break up into smaller droplets with the action of electric forces overcoming the surface tension of the liquid. Since the atomized droplets have the same electrostatic charge, which can prevent the conglomeration of droplets, so electrostatic spraying process performs better.This paper based on the principle of a stable region aimed to simulate the electrostatic atomization process. In the paper, the author analyzed the electrostatic atomization process, and the formulas about calculation of spay voltage, spray current, droplet diameters, etc. And based on the analysis of these calculation formulas about electro-hydrodynamic theory, spay voltage, spray current, droplet diameters, the author established the appropriate model, and did some numerical simulations.Firstly, ICEM was used to establish the geometry and obtain atomization model mesh. The FLUENT software was used to simulate the flow field inside the two nebulizer compartments. The influence of the gas flow rate and compartment shape on the gas flow pattern was studied. We got a stability region of the two structures. Meanwhile, under the condition of stable region, the multiphase flow model and the DPM model were used to simulate the formation process of Taylor-cone and the secondary atomization process at different voltages, surface tensions and viscous of the liquid, respectively.Firstly, the electric equation was loaded by UDS, and the influence of electric field to momentum equation by UDF, when the DPM model was used to simulate the atomization process of the droplets in the air. The results showed that when the voltage exerted on the nozzle changed, the shape of Taylor cone shape would change significantly, but the droplet size changed little. With the properties of liquid changing, the shape of Taylor-cone and the droplet size would also change. Simulation results showed that, at 2000v,3000v,5000v, enhancing the electric field intensity could significantly decrease the average diameter of the droplets within a certain range. Reducing the surface tension of the droplets could significantly decrease the average diameter, while the changes of liquid viscosity had little impact on the average diameter. The research methods and results obtained from the simulation provided an acceptable approach on simulation of electrostatic atomization process with stability principle, and it also provided an important theoretical basis on the selection of electrostatic atomization process parameters.