Aerodynamic performance and flow field losses analysis: A study on nozzle governing turbine with varied regulated nozzle stator installation angle

• Published in: Energy (Oxford) 2024-08, Vol.300, p.131464, Article 131464
• Main Authors: Guan, Yin, Li, Wen, Zhu, Yangli, Wang, Xing, Zhang, Yifeng, Chen, Haisheng
• Format: Article
• Language: English
• Subjects: Compressed air energy storage; Losses analysis; Nozzle governing; Optimized air distribution method; Varied stator installation angle
• ISSN: 0360-5442
• DOI: 10.1016/j.energy.2024.131464

During the energy release process in compressed air energy storage (CAES) system, the air storage pressure gradually diminishes. To optimize turbine performance in this scenario, a judicious air distribution method becomes imperative. This study adopts single nozzle governing method and elucidates the variation in aerodynamic characteristics under rated output work conditions by manipulating regulated nozzle stator installation angle (RNSIA) and total inlet pressure under varying base pressure. When the RNSIA ranges from −10° to 4° under the base pressure of 10.0 MPa, the maximum specific work increment is 13.2 % and efficiency increment is 14.3 % compared with throttle governing. Meanwhile, the maximum specific work increment is 4.0 % and efficiency increment is 2.9 % compared with designed RNSIA. The proportion of throttle entropy increase to the system progressively rises from 5 % to 40 %, mirroring the trend in system entropy increase. To maintain output work requirements, it's advisable to appropriately decrease the RNSIA to boost inlet pressure of the regulated nozzle and mitigate throttling losses. Additionally, the reduction in the RNSIA within a certain range prolongs the duration of the energy release process in the CAES system, which effectively enhances the round-trip efficiency of the CAES system. •Reduced RNSIA leads to an appropriate increase in specific work and efficiency in CAES system.•The maximum relative increment in specific work is 13.2 % compared with throttle governing.•The maximum relative increment in efficiency is 14.3 % compared with throttle governing.•The proportion of throttle entropy increase to the system progressively rises from 5 % to 40 %.