Experimental Investigation And Numerical Simulation Of A Gas Turbine Annular Combustor With Dual-stage Swirler

In this paper A Particle Imaging Vlocimetry (PIV) is employed to measure non-reacting and reacting flow fields of two different model annular combustors with the dual-stage swirler. The effects of different swirlers(dual-stage axial swirler or swirl cup),combustor header structure parameters (vane angles of swirler,size and location of primary hole) and inlet parameters(inlet temperature and fuel/air ratio) on cold and spray combustion flow fields of combustor are investigated by experiment. In addition,influences of different inlet parameters on fuel spray fields of the swirl cup model annular combustor are experimentally studied by PIV.The radial profiles of the exit gas temperature in model annular combustors are measured by multiple-point thermocouple probe. Influences of different swirlers,combustor header structure parameters and inlet parameters on radial profiles of the exit gas temperature are investigated using experiment. The Infrared thermal imager is used to measure wall temperature profiles of the flame tube within the model annular combustor with the dual-stage axial swirler. The multiple-point gas sampling probe and gas analyzer are used to measure combustor performances(lean blowout limit,combustion efficiency,pollutant CO and NO emission) in the dual-stage axial swirler annular combustor. The effects of different inlet temperature and fuel/air ratio,as well as combustor header structure parameters on distributions of wall temperature of combustor and combustor performances are studied experimentally.Experimental data are shown that:1) the non-reacting and reacting flow fields(such as the size of recirculation zone,profiles of velocity and fluctuating velocity ) are affected with varying degrees by swirler type,swirl vane angles of swirler(swirl number),primary hole parameter,inlet temperature,fuel/air ratio. And the effects of swirler type and primary hole parameters on the size and shape of central recirculation zone and profiles of velocity are stronger than swirl number. So reasonable swirler type and primary hole parameter are more important than swirl number to achieve satisfactory flow aerodynamic characteristics. The lengths of central recirculation zone of reacting flow fields are shorter than that of non-reacting flow fields,but the recirculation velocity,fluctuation velocity( u′2,v′2and w′2) and the Reynolds stress(u′v′andv′w′) of reacting flows are higher than those of non-reacting flows. The length of recirculation zone decreases with increase in the inlet temperature under the non-reacting and reacting flows .2) The swirler type,combustor header structure parameter and inlet parameters have some effects on radial profiles of the exit gas temperature within the model annular combustors ,but trends of temperature profiles are similar. The exit gas temperature increases with increase of inflow temperature and fuel/air ratio.3)The swirl vane angles of swirler,primary hole parameter ,tinlet temperature and fuel/air ratio have effects on combustor performances and the wall temperature of flame tube. The effect of fuel/air ratio on combustor performances is obvious,but it on profiles of wall temperature is weak. The results of study are useful for the design of high temperature rise combustor.4) The fuel spray fields of the swirl cup model annular combustor are affected with varying degrees by inlet temperature,fuel/air ratio. Effects of inlet temperature are more obvious than the fuel/air ratio. The commercial software FLUENT is applied to predicting three-dimensional non-reacting and reacting integrated flow fields for two model annular combustors with the dual-stage swirler. The influences of two different model annular combustors on non-reacting and reacting flow fields,combustor performances as well as wall temperature profiles of flame tube are analyzed numerically. Calculations are in agreement with the experimental data. It is shown that the numerical models and procedure are reasonable. Results of study are useful for the optimum design and development of the advanced annular combustor.