Design And Experimental Research Of Composite Spray Nozzles For Heavy And Residual Oil

Aiming at the problems of difficult-burning for high viscosity heavy oil and residual oil, a structure-alterable composite spray nozzle for atomizing the bad fuel was designed, by comprehensive using of effervescent atomization technology and swirl atomization technology, access to a large number of related literatures. Many experiments were carried out with the help of LDV system and LS-2000 system to study the relationship between the atomization characteristics and the atomizer inner structural parameters, operation parameters. Conclusions as follows were draw from the experimental study. There is no coupling relationship between diameter SMD and speed produced by the atomizer. Within the range of experiments, the atomization characteristic of the atomizer is better when injection area ratio of air to liquid approaches 2.0 and length-to-diameter ratio of mix-chamber approaches 2.0. When GLR is between 0.02 and 0.04 and the injection pressure ratio of air to liquid is between 0.8 and 1.2, the atomization performance is better. With the increase of GLR, droplet size SMD showed a rapid decreasing trend, the droplet size SMD significantly reduce the tendency to flatten when the GLR approaches 0.04 and the best GLR should be controlled in the range of 0.02 to 0.04. The experimental data were regressed with different format to find out the relationship between liquid flux Ql and GLR, orifice flux coefficientμand GLR. Based on the principle of dimensional analysis and similarity criteria,empirical formula between SMD and many factors by the least square method. The experimental result is a matter of great significance to atomizer design and locale application. Using theoretical atomization model to Analysis experimental data, it predicts that the calculated and experimental SMD values have the consistent trend of GLR by the Sojka atomization model and Lund atomization model. Thanks to the model, the best GLR should be controlled in the range of 0.02 to 0.04, error of less than 29% to 35%, verifying the reasonableness of model selection. A designed process of composite spray nozzle was compiled by using VB6.0 software, achieving visualization and simplicity of the calculation of the nozzle design process, savings cost of calculations greatly.