Aeroengine Inter-Stage Turbine Buner Technology

In order to improve performance of aviation gas turbine, the turbine inlet temperature must be increased while enhancing the compressor over pressure ratio, but under modern technical conditions, the compressor over pressure ratio was confined by its surge margin, and turbine materials limited the turbine inlet temperature, these above conditions limited the development of aero engine technology. Adding a inter-stage turbine burner between high pressure turbine and low pressure turbine was seemed a effective method to increase specific thrust.Summarizing today’s gas turbine engine inter-stage turbine burner technology, analyzing the existing problem in nowadays research, results show that there are two different views on the engine overall performance calculations, one view is that inter-stage turbine burner significantly enhancing specific thrust while increasing little thrust specific fuel consumption, the other view is that specific thrust increasing need similar incremental fuel consumption, and non-uniform outlet temperature distribution of combustor is also an important problem in the experiment.Compiling a program to resolve the opinions differences of engine overall performance, comparing the different performances between partially ideal cycle and non-ideal cycle, using index such as specific thrust increase ratio and fuel consumption increase ratio, to analyze flight target of inter-stage turbine burner engine, researching the advantages and disadvantages of high temperature rise combustor engine and inter-stage turbine burner engine, point out heat distribution methods of the main burner and secondary combustor. Finally the inter-stage turbine burner engine overall performance was optimized calculation, specific thrust increase30%while fuel consumption increase7%under F100-PW229parameters.Four cases of adding a inter-stage turbine burner in the engine inter transition duct were investigated by numerical simulation, firstly, the case of setting up a circumferential cavity outside the inter transition duct and a radial cavity on the vane was studied, secondly, based on the first case, cooling gas injecting into circumferential cavity was calculated, thirdly, a case of installing a circumferential V-gutter flame stabilizer in the duct was researched, fourthly, a case of setting up several radical V-gutter flame stabilizer while injecting fuel from a single injector and three injectors was studied, finally, the forth case with three injectors was selected as the experimental case in research program.Liquid fuel spray characteristics in blade passage of low pressure turbine was tested, Fraunhofer diffraction technique was used to measure droplet diameter, and the spray trajectory was recorded by CCD camera, the inlet velocity in experiments is56m/s～91m/s and the pressure differential of injector is50kPa-400kPa, fuel was injected to pressure side, suction side and reverse side at the blade leading edge respectively. Results show that spray trajectory in turbine passage is influenced by liquid-air momentum ratio, blade-turning angle as well as blade solidity. Spray trajectory is close to blade surface when injecting to blade passage, and flame is easy to burn out the vane, and droplet will hit the blade trailing edge to form carbon deposit when injecting to pressure side, droplet is far from the blade when reverse injection at the middle of passage. At real working condition, the spray fineness can meet combustor requirement.Based on above research, a combustion experiment with radical V-gutter flame stabilizer was tested, the lean blowout, lean light-up characteristics, combustion efficiency and outlet temperature distribution were evaluated. A single hole injector and three-hole injector were used to spray, the trailing edge width of V-gutter was respectively9mm and13mm, the inlet mass flow rate is0.2kg/s,0.25kg/s,0.3kg/s,0.35kg/s/,0.4kg/s, and the temperature of inlet flow is573K. Results show that the three-hole injector spraying along the flow has a better ignition and flameout feature, the trailing edge width of the stabilizer of13mm, lateral and oblique injection has the highest combustion efficiency, and also have a well-distributed temperature.An experiment of installing several radical V-gutter stabilizers under real condition should be tested in the future.