Research On Atomization Characteristics Of High-viscosity Biomass Fuel Directly Burned Under High-pressure Oxygen-enriched Conditions

In the application process of liquid fuel,in order to improve the combustion efficiency and reduce the emission of harmful substances,the atomization process is generally carried out.Atomization and combustion are two closely related physical and chemical processes.Compared with ordinary diesel,the higher kinematic viscosity,density and surface tension of biomass fuel make it difficult to atomize under the same conditions,and the atomization quality is poor,resulting in carbon deposition and poor flame stability during combustion.Problems,so improving the quality of biomass fuel atomization is of great significance for its expanded application and commercial development.In this paper,the research method of combining experiment and simulation is used to investigate the atomization characteristics of Jatropha curcas oil and Jatropha curcas biodiesel.First,quantitative analysis of the physical and chemical parameters of the two biomass fuels was conducted to grasp the laws of changes in physical properties such as kinematic viscosity and surface tension,which affect the quality of the atomization,with temperature;then the incident pressure of the atomization was 0.1MPa to 1.1MPa and the air rich Under the condition of oxygen concentration of 21% ? 31%,two kinds of biomass fuel atomization process are numerically simulated and the results of atomization are discussed;finally,the biomass fuel atomization system is used to perform the atomization process of Xiaotongzi oil and Xiaotongzi biodiesel The test analysis uses the same working conditions as the simulation calculation to obtain the conclusion of the test atomization process under the corresponding working conditions and verifies the calculation model.This article draws the following conclusions:(1)In the process of temperature increase from 20 ? to 60 ?,the kinematic viscosity of Jatropha biodiesel has the greatest correlation with temperature.Compared with the kinematic viscosity at 20 ?,the kinematic viscosity value of Jatropha curcas biodiesel is reduced by 67.0% at 60 ?;the density of Jatropha curcas oil is the least sensitive to temperature changes,with the temperature increasing,the density phase at 60 ? Compared with the density value at 20 ?,the density value is reduced by 2.4%.(2)Under isothermal conditions,the average diameter(D32)of the two biomass fuel fuels decreases with increasing incident pressure;the total atomizing surface area,atomizing velocity,and atomizing penetration distance increase with increasing incident pressure.There is a critical value for the influence of the incident pressure on the average diameter of Soter.After the atomization pressure of Jatropha curcas oil and Jatropha biodiesel reaches 0.8 MPa and 0.7 MPa,respectively,the average diameter of Sauter does not change significantly.Compared with ordinary nozzles,swirl nozzles are more conducive to the mixing of the gas-liquid two phases and the effect of breaking the droplets.(3)Under isobaric conditions,with the increase of air enriched oxygen concentration,the average diameter of Jatropha curcas oil and Jatropha biodiesel Sauter showed a gradual decrease trend,and the total surface area of atomization increased with the increase of air enriched oxygen concentration The height gradually increases,and the atomization speed gradually decreases.At the same time,when the air enrichment concentration reaches 29%,the average diameter of Sotzag Oil Soter reaches the minimum;when the air enrichment concentration reaches 27%,the average diameter of Sotere reaches the minimum.(4)Through curve fitting and analysis of droplet particle size number density,the fitting formula of the axial Sauter average diameter change under isothermal conditions is obtained.The reliability and accuracy of the established numerical calculation model are verified.