| Reduce the loss of turbine cascade,the development of high-power ultra supercritical units,for improving fuel efficiency,energy saving and emission reduction is of great significance.The advanced blade design and high-performance blade design are the key means of improving the efficiency of the cascade flow.Harbine Turbine Company Limited designed and production of 1000 Mw ultra-supercritical units represented the highest level of the domestic steam turbine industry,so through the plane cascade and annular cascade blowing experiments and numerical simulation,in its application to the actual project to verify its aerodynamic performance meets the design goals,and then study the flow characteristics of advanced blades,aerodynamic performance and design techniques,digestion and absorption of advanced large enthalpy drop blade design concept,for the development of more advanced and more efficient steam turbine and gas turbine has a role in the past.For studying the aerodynamic characteristics of advanced large enthalpy drop blades,we selected 1000 Mw ultra-supercritical unit medium pressure 9th grade stator and rotor as the research object,and the blow-wind test of the six sets of plane cascade with a high cross-sectional lprofile,which is 10%,50% and 90% blade height,is carried out by different angle.With the Harbin Institute of Technology low-speed wind tunnel test rig,measuring the static pressure,the outlet airflow angle and the total pressure loss in the middle of the blade hegiht.By analyzing the results,we found that the blade profile along the blade height of the 9th grade stator and rotor are after-loaded:At zero angle,the minimum pressure point of the six sections of the blade profile suction surface is after 70% axial chord length.Blade profile aerodynamic performance is excellent:Under the design incidence,the profile loss is between 1.518% and 2.378%,The lag angle is between 1.3569°and 1.81°.Under the tested incidence,The fluctuation of profile loss is within 48%,The fluctuation of lag angle is within ±0.546°.The top blade profile of the rotor have better aerodynamic performance than the other five.In order to verify the accuracy of the test results,the numerical simulation of the 50% leaf high profile plane cascade is carried out.The results of the different turbulence models are analyzed.The results of the k-? turbulence model are in good agreement with the experimental results.And then the numerical study of the change of Mach number and variable incidences.The Mach number of the outlet changed from 0.2 to 0.8,and the aerodynamic load of the blade was gradually reduced.The lowest pressure points of the leaf suction surface gradually move backward.The cascade loss decreases first and then increases,which is the smallest at about 0.5 Mach number.The incidence change from-30 ° to 30 °,the blade aerodynamic load gradually increases,but the position of the blade suction surface minimum pressure point remains the same.The total pressure loss decreases first and then increases,which is the smallest at zero incidece of 3.695%.The maximum negative incidence and the maximum positive incidence were increased by 10% and 34.37% respectively.The three-dimensional separation line of the suction surface passage vortex increases gradually,the intensity of the lower passage vortex is greater than the upper passage vortex.The incidence is within ± 20 °,and the blade has excellent adaptability.Comparing the numerical simulation results of straight and three-dimensional blade,we found the load variation of the large enthalpy drop blade along the blade height is caused by the positive-curved stacking of the profile along trailing edge.Profile loss accounts for about 60% of the loss of the cascade.Blade profile after-loaded,blade positive-curved,The leading edge circle is similar to the "fish head" type of flow line,aerodynamic design along the blade height varied,all together contribute the ultra-supercritical unit blades to achieve excellent aerodynamic performance. |
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