Experimental And Simulation Research On Dynamic Characteristics Of Liquid Hydrocarbon Droplets Under Gas Turbine Combustor Working Conditions

Transportation of natural gas is accomplished by the pressurizing through the gas turbine-driven compressor set in gas station.Under normal operating conditions,pressure decreasing or temperature decreasing in the pipeline could lead to the formation of liquid hydrocarbons,which could seriously affect the safe and efficient operation of gas turbine.Some of liquid hydrocarbons can enter the combustor of the gas turbine along with the natural gas and get involved in the combustion process.The rest of the unburned liquid hydrocarbon drops can stick to the periphery of the burner,leading to ablation of burners and carbon deposits.Combustion of liquid hydrocarbon can result in the rearward shift of the flame and the ablation of turbine blades.Large liquid hydrocarbon droplets can even impinge on the wall of the chamber or turbine blades,leading to burnt or cracks on the wall of combustor,even the turbine blades failure.The dynamic process of liquid hydrocarbon in the combustor is essentially a complex two-phase flow phenomenon,which was investigated by this dissertation according to the following four steps.Firstly,the spatial distribution of liquid hydrocarbons entering the combustion chamber through a nozzle was studied by using the PIV system,focusing on the atomization shape,the distribution of velocity,and the size of liquid hydrocarbon droplets.Secondly,the evaporation of liquid hydrocarbon droplets in the high temperature environment of combustor was numerically studied to analyze the evaporation rate,distortion,velocity change,etc.Thirdly,the collision of hydrocarbon drops on the surface of the combustor and turbine blades,the deformation of hydrocarbon droplet and the subsequent spreading on the wall surface were numerically investigated.Finally,to avoid flame retraction and droplet impingement on the blades,enhancement of the evaporation of liquid hydrocarbon droplets by breaking up the droplets through electrical charging was experimentally studied.It was found that different charging voltages leading to different flow patterns,and the breakup frequency of the droplets indicated that electricity charging was effective to enhance the breakup of droplets.