Design and analysis of 10MW 1 + 1/2 supercritical carbon dioxide counter-rotating turbine

Abstract

In order to reduce the axial size of the supercritical carbon dioxide (SCO₂) Brayton cycle system and enhance its power-weight ratio, this paper proposes a counter-rotating design approach for SCO₂ turbines. The design process primarily involves 1D aerodynamic design based on theoretical analysis of velocity triangles and blade geometry modeling. A three-stage 10 MW SCO₂ axial turbine is selected as a test case and redesigned as a 1 + 1/2-stage counter-rotating turbine (CRT) configuration. Compared with the three-stage turbine, the axial length of the CRT is reduced by 63.5%. Subsequently, the performance of the designed counter-rotating SCO₂ turbine is validated through detailed numerical analysis utilizing the three-dimensional computational dynamics method, considering real gas effects of CO₂ by employing a physical property database for property calculations. The computational fluid dynamics results demonstrate that under design conditions, the isentropic efficiency is 92.4%, which represents a 12.4 percentage points improvement over the design target and satisfactorily meets the design objectives. Further analysis on the flow field was conducted, and it was found that the turbine streamlines are uniform, the entropy increase is concentrated at the trailing edge of the blades, and the average absolute outlet flow angle is 0° approaching the axial direction. The behavior of the CRT under off-design conditions is also discussed.

Keywords

Counter-rotating turbine / SCO₂ turbine / Aerodynamic design / Numerical simulation

References

[1] Crespi F, Gavagnin G, Sánchez D, et al. . Supercritical carbon dioxide cycles for power generation: a review. Appl Energy, 2017, 195: 152-183

[2] Ye X, Pan W, You Y (2017) Application of supercritical carbon dioxide Brayton cycle in power generation fields. Power Energy 38(3):343–347

[3] Han W, Zhang Y, Li H, et al. . Aerodynamic design of the high pressure and low pressure axial turbines for the improved coal-fired recompression SCO₂ reheated Brayton cycle. Energy, 2019, 179: 442-453

[4] Stepanek J, Syblik J, Entler S (2022) Axial sCO₂ high-performance turbines parametric design. Energy Convers Manag 274:116418. https://doi.org/10.1016/j.enconman.2022.116418

[5] Zhang H, Zhao H, Deng Q et al (2015) Aerothermodynamic design and numerical investigation of supercritical carbon dioxide turbine. No. ASME GT2015-42619

[6] Lv G, Yang J, Shao W, et al. . Aerodynamic design optimization of radial-inflow turbine in supercritical CO2 cycles using a one-dimensional model. Energy Convers Manag, 2018, 165: 827-839

[7] Wintucky WT, Stewart WL (1958) Analysis of two-stage counterrotating turbine efficiencies in terms of work and speed requirements. No. NACA-RM-E57L05

[8] Louis JF (1985) Axial flow contra-rotating turbines. No. ASME 85-GT-218. https://doi.org/10.1115/85-GT-218

[9] Bellocq P, Garmendia I, Legrand J et al (2016) Preliminary design and performance of counter rotating turbines for open rotors: Part II—0-D methodology and case study for a 160 PAX aircraft. No. ASME GT2016-57921

[10] Rajeevalochanam P, Sunkara SNA, Murthy SVR, et al. . Design of a two spool contra-rotating turbine for a turbo-fan engine. Propuls Power Res, 2020, 9(3): 225-239

[11] Cai R, Wu W, Fang G (1992) Basic analysis of counter-rotating turbines. Int J Turbo Jet Eng 9(1):1–10. https://doi.org/10.1515/TJJ.1992.9.1.1

[12] Ji L, Zhong WT, Xu JZ (2001) Primary analysis and design of a vaneless counter-rotating turbine. J Eng Thermophys 22(2):167–170

[13] Liu Y, Zhuge W, Zheng X, et al. . Study of mechanism of counter-rotating turbine increasing two-stage turbine system efficiency. Int J Fluid Mach Syst, 2013, 6(3): 160-169

[14] Zhou Y, Liu H, Li W, et al. . Aerodynamics design of two-stage vane-less counter-rotating turbinec. J Therm Sci, 2011, 20: 406-412

[15] Fang X, Liu S, Wang P (2005) Design and analysis of LP-vaneless contra-rotating turbine. J Propuls Technol 26(141):234–238. https://doi.org/10.3321/j.issn:1001-4055.2005.03.010

[16] Zhao W, Sui XM, Zhao QJ. Counter-rotating turbine flow mechanism and aerodynamic design. Sci Sin Technol, 2020, 50: 1376-1390

[17] Luo D, Sun X, Huang D. Design of 1+ 1/2 counter rotating centrifugal turbine and performance comparison with two-stage centrifugal turbine. Energy, 2020, 211 118628

[18] Kumaran R S, Alone D B, Nassar A et al (2021) Preliminary aerodynamic design of a S-CO₂ axial turbine. No. ASME GTINDIA2021-76454

[19] Yang Z, Huoxing L, Wei L et al (2011) Aerodynamics design of two-stage vane-less counter-rotating turbinec. J Therm Sci 20(5):406−412. https://doi.org/10.1007/s11630-011-0488-z

[20] Zhao W, Wu B, Xu J. Aerodynamic design and analysis of a multistage vaneless counter-rotating turbine. J Turbomach, 2015, 137(6 061008

[21] Kacker SC, Okapuu U. A mean line prediction method for axial flow turbine efficiency. J Eng Power, 1982, 1041): 111-119

[22] Dunham J, Came PM (1970) Improvements to the Ainley−Mathieson method of turbine performance prediction. J Eng Power 92(3):252–256. https://doi.org/10.1115/1.3445349

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