Investigation On Operating Characteristics Of Thermostable Atomizor

With the development of aero engine technology which requires the inlet temperature and temperature rise of combustor are increasing, the pole of injector and the nozzle body always exposure in the high temperature gas which would heat the fuel in the injector and results in that the fuel would be deposited, coked and attached in the injector. The serious deposited and coked fuel would block the flow of injector which would effect the spray cone and the atomization quality. In this paper, based on the demand of high temperature rise combustor, the operating characteristics of the thermostable atomizer were investigated with numerical simulation and experimental methods.The thermostable atomizer was designed and produced. The influences of inlet temperature, inlet velocity, fuel injection pressure and oil channel size on the flow and heat exchange characteristics of atomizer were discussed and the heat protection technology of the thermostable atomizer was explored. Using phase Doppler particle analyzer(PDPA) and Malvern particle size analyzer, the spray characteristics of the thermostable atomizer were tested. An axial flow combustor with the thermostable atomizer was ignited and the effect of inlet velocity, equivalence ratio and size of heat shields on the outlet temperature distribution and the oil temperature in pole of atomizer were investigated. The much results as follows:(1) According to the structural characteristics and technical requirements of the high temperature rise combustor, the high temperature resistant fuel atomization nozzle is designed and processed, including heat insulation screen, fuel injection rod, centrifugal nozzle body, blow up and so on.(2) Build up resistance to high temperature fuel oil injection nozzle rod heat transfer calculation model, the effects of the inlet temperature, intake speed, size of the oil channel, heat insulation screen plan, arrangement of the injection rod and oil channel fuel temperature characteristics, fuel pipe and the nozzle flow and Jette changing regularity, increase the size of the oil channel is conducive to lowering the injection rod wetted wall temperature and fuel outlet temperature, take the best heat insulation effect of the heat shield for the moment.(3) Establish fuel rod thermal protection test system, including gas heater, direct combustion chamber casing, fuel rod thermal protection test, temperature testing system of inlet temperature, inlet velocity, size of the oil channel, heat shield plan, arrangement of the injection rod and oil diesel oiltemperature characteristics, and the comparative analysis of numerical calculation results verify calculation method and the results are reliable.(4) A simplified calculation model of centrifugal nozzle was established. The flow pattern of the centrifugal nozzle under different fuel supply pressures, the shape and breaking of the outlet oil film and the characteristics of the fuel flow rate of the outlet were discussed. The centrifugal nozzle atomization characteristics test system was established. The atomization characteristics such as PDPA and Malvin particle size analyzer were used to study the atomization characteristics, such as the N value(particle size distribution index), volume fraction and so on.(5) Established DC chamber test platform, resistant to high temperature fuel nozzle ignition test,changing the combustion chamber inlet velocity, equivalent fuel air ratio and fuel rod thermal insulation screen size, the combustion chamber temperature rise, exit temperature distribution, fuel injector fuel temperature variation.