DOI QR코드

DOI QR Code

Off-design Characteristics for Ambient Air Temperature and Turbine Load of Gas Turbine Pre-swirl System

가스터빈 프리스월 시스템의 외기 온도와 터빈 부하 조건에 따른 탈설계점 특성 분석

  • Park, Hyunwoo (Dept. of Mechanical Convergence Engineering, Hanyang University) ;
  • Lee, Jungsoo (Dept. of Mechanical Engineering, Hanyang Universtiy) ;
  • Cho, Geonhwan (Gas Turbine System Integration Team, Doosan Heavy Industries & Construction) ;
  • Cho, Jinsoo (Dept. of Mechanical Engineering, Hanyang Universtiy)
  • Received : 2019.11.07
  • Accepted : 2019.11.26
  • Published : 2019.12.01

Abstract

The pre-swirl system is the device that minimizes energy loss of turbine cooling airflow from the stationary parts into rotating parts. In this paper, an off-design analysis was conducted for the ambient air temperature and turbine load conditions. The discharge coefficient was constant for ambient air temperature and turbine load. However, adiabatic effectiveness was increased. This is due to the volume flow rate. The volume flow rate was increased at higher ambient temperature and higher turbine load. It means that the volume of cooling air was increased and the cooling performance of the air was improved. Consequently, adiabatic effectiveness increased by 30.46% at 100% turbine load compared to 20% turbine load. And increased by 18.42% at 55℃ ambient air temperature compared to -20℃ ambient air temperature.

가스터빈 이차 유로의 프리스월 시스템은 터빈의 효율을 높이고 소재의 수명을 연장하기 위해 설치되는 냉각 장치이다. 본 연구에서는 프리스월 시스템의 설계점을 기준으로 가스터빈 외기 온도와 터빈 부하 변화에 따른 탈설계점 분석을 수행하였다. 탈설계점에서 내부 유동의 특성을 분석하기 위하여 유량계수와 단열계수를 비교하였다. 터빈 부하 증가에 따라 시스템 내부 냉각 공기의 체적 유량이 증가하였고, 단열계수 또한 20% 터빈 부하와 비교하여 100% 터빈 부하에서 30.46% 상승하였다. 외기 온도가 증가할수록 질량 유량과 냉각 공기의 밀도는 감소하였지만 체적 유량은 상승하였으며, 결과적으로 프리스월 시스템 내부의 냉각 성능은 향상되었다. 프리스월 시스템 출구에서 -20℃ 외기 온도와 비교하여 55℃ 외기 온도의 단열계수는 14.82% 향상되었다.

Keywords

References

  1. Khartchenko, N., and Kharchenko, V., Advanced energy systems, 2013.
  2. Dittmann, M., Geis, T., Schramm, V., Kim, S., and Wittig, S., "Discharge Coefficients of a Preswirl System in Secondary Air Systems," Journal of Turbomachinery, Vol. 124, No. 1, 2001, pp. 119-124. https://doi.org/10.1115/1.1413474
  3. Javiya, U., Chew, J., Hills, N., and Scanlon, T., "A Comparative Study of Cascade Vanes and Drilled Nozzle Designs for Pre-Swirl," Proceedings of the ASME Turbo Expo 2011, June 6-10, 2011, pp. 913-920.
  4. Bricaud, C., Geis, T., Dullenkopf, K., and Bauer, H.-J., "Measurement and analysis of aerodynamic and thermodynamic losses in pre-swirl system arrangements," Proceedings of the ASME Turbo Expo 2007, May 14-17, 2007, pp. 1115-1126.
  5. Lee, J., Lee, H., Kim, D., and Cho, J., "Pre-swirl vane geometry optimization to improve discharge coefficient of gas turbine pre-swirl system," Transactions of the Korean Society of Mechanical Engineers, B, Vol. 42, No. 2, 2018, pp. 101-110. https://doi.org/10.3795/KSME-B.2018.42.2.101
  6. Carcasci, C., Costanzi, F., and Pacifici, B., "Performance analysis in off-design condition of gas turbine air-bottoming combined system," Energy Procedia, Vol. 45, 2014, pp. 1037-1046. https://doi.org/10.1016/j.egypro.2014.01.109
  7. Carcasci, C., Facchini, B., Gori, S., Bozzi, L., and Traverso, S., "Heavy Duty Gas Turbine Simulation: Global Performances Estimation and Secondary Air System Modifications," Proceedings of the ASME Turbo Expo 2006, May 8-11, 2006, pp. 527-536.
  8. Schobeiri, MT., "Improving the Efficiency of Gas Turbines During Off-Design Operation by Adjusting the Turbine and Compressor Blade Stagger Angles," Journal of Applied Mechanical Engineering, Vol. 7, No. 1, 2018, pp. 1-10.
  9. Karaby, H., Chen, J.-X., Pilbrow, R., Wilson, M., and Owen, J. M., "Flow in a "Cover-Plate" Preswirl Rotor-Stator System," Journal of Turbomachinery, Vol. 121, No. 1, 1999, pp. 160-166. https://doi.org/10.1115/1.2841225
  10. Benim, A. C., Brillert, D., and Cagan, M., "Computational Investigation of the Flow in Pre-Swirl Stator-Rotor Systems," International Journal of Computational Methods, Vol. 1, No. 2, 2004, pp. 329-343. https://doi.org/10.1142/S0219876204000125
  11. Javiya, U., Chew, J., Hills, N., Zhou, L., Wilson, M., and Lock, G., "CFD analysis of flow and heat transfer in a direct transfer pre-swirl system," Proceedings of the ASME Turbo Expo 2010, June 14-18, 2010, pp. 1167-1178.
  12. Benim, A. C., Brillert, D., and Cagan, M., "Investigation into the Computational Analysis of Direct-Transfer Pre-swirl System for Gas Turbine Blade Cooling," Proceedings of the ASME Turbo Expo 2004, June 14-17, 2004, pp. 453-460.
  13. Kim, J., Kang, Y., Kim, D., Lee, J., Cha, B., and Cho, J., "Optimization of a high pressure turbine blade tip cavity with conjugate heat transfer analysis," Journal of Mechanical Science and Technology, Vol. 30, No. 12, 2016, pp. 5529-5538. https://doi.org/10.1007/s12206-016-1121-6