Performance analysis and optimized control strategy for a three-shaft, recuperated gas turbine with power turbine variable area nozzle. (5th January 2020)

• Record Type: Journal Article
• Authors: Zhou, Qiao; Yin, Zhao; Zhang, Hualiang; Wang, Tao; Sun, Wenchao; Tan, Chunqing
• Is Part Of: Applied thermal engineering. Volume 164(2019)
• Publication Date: 2020-01-05
• Subjects: Recuperated cycle -- Three-shaft gas turbine -- Power turbine variable area nozzle -- Performance analysis -- Optimized control strategy; Heat engineering -- Periodicals; Heating -- Equipment and supplies -- Periodicals; Periodicals; 621.40205
• DOI: 10.1016/j.applthermaleng.2019.114353
• Languages: English
• ISSNs: 1359-4311

Abstract

Highlights: Detailed part-load performance analysis and optimization for a three-shaft, recuperated gas turbine is conducted. A modified recuperator simulation model is proposed based on experiment. Effect of power turbine shaft speed and variable area nozzle (VAN) angle on engine performance improvement is analyzed. Influence of temperature limits and ambient temperature on optimized control of VAN angle is studied. Optimized control strategy for power turbine shaft speed and VAN angle is proposed. Abstract: Performance analysis and optimization for a three-shaft, recuperated gas turbine with power turbine variable area nozzle (VAN) is conducted in this paper. A modified recuperator simulation model is obtained from recuperator experiment. A gas turbine performance simulation program is established. The influence of power turbine shaft speed on engine performance is studied and optimized control of power turbine shaft speed is proposed. Comparative performance analysis proves VAN angle control improves engine performance, but leads to less compressor surge margin and increased risk of over temperature. The optimized control of VAN angle under different safety operation temperature limits and ambient temperature is investigated. Power turbine shaft speed barely influences the optimized control of VAN angle, but temperature limits and ambient temperature greatly do. By decoupling power turbine shaft speed and VAN angle, an optimized control strategy for power turbine shaft speed and VAN angle is proposed, which brings 6.37%, 15.88%, 47.80% increases in output power, and 10.84%, 25.59%, 64.97% increase in thermal efficiency when relative high-pressure shaft speed is 0.95, 0.90 and 0.85, respectively. Maximum thermal efficiency could be achieved at part-load conditions rather than design-point if temperature limit is relaxed.