Session: 30-14 Turbines 3 and Fluids 2

Submission Number: 177832

Flow Characteristics and Partial Admission Loss Analysis for a Supercritical Carbon Dioxide Axial-Flow Turbine 

Supercritical carbon dioxide (S-CO₂) Brayton cycles are regarded as one of the most promising power generation systems due to their high efficiency and compact structure. For low-power S-CO₂ cycles, partial admission design can be employed in the turbine to reduce significant secondary flow losses that arise from excessively short blade heights under full admission conditions. However, most existing loss models for partial admission turbines are derived from experimental data on turbines using conventional working fluids such as air and steam. Whether these models can accurately predict partial admission losses in S-CO₂ turbines and be reliably applied in their design remains unclear. This study conducts computational fluid dynamics (CFD) simulations of S-CO₂ axial-flow turbines with partial admission ratios ranging from 0.05 to 0.8. The flow characteristics of partial admission S-CO₂ turbines are investigated, with particular focus on the flow non-uniformity at the ends of the active sector. The effects of such non-uniformity and the flow in the inactive sector on turbine efficiency are analyzed. A comparison is made between the partial admission losses predicted by CFD and those estimated by existing loss models. The results indicate that existing models overestimate partial admission losses in S-CO₂ turbines, especially when the partial admission ratio is below 0.3, where the discrepancy becomes more pronounced.

Presenting Author: Zhuo Hu State Key Laboratory of Intelligent Green Vehicle and Mobility, School of Vehicle and Mobility, Tsinghua University

Presenting Author Biography: Zhuo Hu is a Ph.D candidate at Turbo ePower Group, State Key Laboratory of Intelligent Green Vehicle and Mobility, School of Vehicle and Mobility, Tsinghua University. His research direction is flow mechanisms of supercritical carbon dioxide turbines.

Authors:

Zhuo Hu State Key Laboratory of Intelligent Green Vehicle and Mobility, School of Vehicle and Mobility, Tsinghua University
Hongsheng Jiang State Key Laboratory of Intelligent Green Vehicle and Mobility, School of Vehicle and Mobility, Tsinghua University
Weilin Zhuge State Key Laboratory of Intelligent Green Vehicle and Mobility, School of Vehicle and Mobility, Tsinghua University
Yuping Qian State Key Laboratory of Intelligent Green Vehicle and Mobility, School of Vehicle and Mobility, Tsinghua University
Yangjun Zhang State Key Laboratory of Intelligent Green Vehicle and Mobility, School of Vehicle and Mobility, Tsinghua University