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Institute of Korean Electrical and Electronics Engineers (한국전기전자학회)
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A Study on the Improvement of Optimal Load Range for Sliding Pressure Operation of coal-fired Power Plant

석탄화력 발전소 최적 변압운전 부하 범위 개선에 대한 연구

  • Lee, Sang-Hun (Dept. of Mechanical Facility Control Engineering, Korea University of Technology and Educatio) ;
  • Wang, Min-Seok (Dept. of Mechanical Facility Control Engineering, Korea University of Technology and Educatio) ;
  • Wee, Sang-Bong (Dept. of Mechanical Facility Control Engineering, Korea University of Technology and Educatio) ;
  • Son, Yung-Deug (Dept. of Mechanical Facility Control Engineering, Korea University of Technology and Educatio)
  • Received : 2019.06.05
  • Accepted : 2019.06.27
  • Published : 2019.06.30
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Abstract

The coal-fired power plant is operated by a combined operation method, which is operated by sliding pressure operation under low load and by fixed pressure operation under high load for improved efficiency. The combined operation is divided into two and three valve open modes. Each plant is operated by selecting the turbine control valve mode in accordance with the manufacturer's recommendation, but is not really operating at the optimal sliding pressure operation according to load range, also Load range of each plant is configured differently. The internal efficiency of the high-pressure turbines is reduced due to loss of the turbine valves and the plant efficiency is reduced. To solve these problems, In this paper, the optimum load range is selected through the analysis method of thermal performance by each load in order to improve the optimum variable pressure operation load range by turbine control valve mode.

석탄화력발전소는 저부하에서 효율 향상을 위해 변압운전으로, 고부하에서는 정압으로 운전하는 복합변압운전 방식으로 운전하고 있으며, 복합변압운전에는 2밸브 및 3밸브 전개모드로 구분되어 운영되고 있다. 각 발전소는 제작사 권고에 따라 터빈제어밸브 모드를 선택하여 운전하고 있으나 최적의 변압운전 부하범위로 운전되고 있지 않고, 각 발전소별 부하범위 또한 상이하게 구성 되어있다. 최적의 변압운전 부하범위로 설정되지 않으면 터빈밸브 교축 손실 발생에 따른 고압터빈 내부효율 저하가 발생되어 플랜트 효율이 저하된다. 이러한 문제점을 개선하기 위해 본 논문에서는 터빈제어밸브 모드별 최적의 변압운전 부하 범위를 개선하기 위해 각 부하별 열 성능 분석 방법을 통해 최적의 부하범위를 선정하고자 한다.

Keywords

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Fig. 1. Schematic and HMI of steam turbine power plant. 그림 1. 스팀터빈설비 계통도 및 제어화면

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Fig. 2. Configuration of CV and MSV in turbine. 그림 2. CV와 MSV의 구성 터빈제어밸브

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Fig. 3. Pressure characteristic of the 2/ 3 valve open mode. 그림 3. 2/ 3 밸브 전개 모드의 압력특성

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Fig. 4. Thermal stress characteristic in Sliding/Constant Pressure Operation. 그림 4. 정압/변압 운전시 열응력 특성

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Fig. 5. Efficiency of sliding pressure operation at the 2 valve open mode. 그림 5. 2밸브 전개모드에서 변압운전의 효율

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Fig. 6. Efficiency of sliding pressure operation at the 3 valve open mode. 그림 6. 3밸브 전개모드에서 변압운전의 효율

Table 1. Load range and pressure comparison in sliding pressure operation. 표 1. 화력발전소 변압운전 부하범위 및 압력비교

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References

  1. S. H. Park, D. R. Rhim, C. S. Yeom, J. M. Cha, J. U. Shin, C. S. Lee, "Thermo-Economic Evaluation of 500 MW Class Coal Fired Power Plant Combined with Supercritical Carbon Dioxide Brayton Cycle," Journal of Energy & Climate Change, vol.11, no.1, pp.1-12, 2016.
  2. G. P. Lim, M. S. Kim, I. K. Choi, D. Y. Park, H. Y Kim, "The Development Of Program Based On Model to Control Generator Output in Power Plant," The transactions of The Korean Institute of Electrical Engineers, vol.59, no.3, pp.614-622, 2010. https://doi.org/10.5370/KIEE.2010.59.3.614
  3. J. K. Lee, Y. S. Ahn, H. Jung, Y. K. Lee, B. S Han, "The Development of Full-Scope Replica Simulator for Variable Supercritical Pressure Once-through Fossil Power Plants," Journal of Institute of Control, Robotics and Systems, vol.4, no.3, pp.392-398, 1998.
  4. J. H. Woo, I. K. Choi, D. Y. Park, J. A. Kim, "Procedure to Verify the Turbine Control Function of a Steam Turbine Power Plant," in Proc. of the 2010 KIEE Conference, pp.1693-1694, 2010.
  5. Goutam Khankari, Sujit Karmakar, "Operational optimization of turbo-generator (TG) cycle of a 500MW coal-fired thermal power plant," 2014 6th IEEE Power India International Conference (PIICON), pp.1-6, 2014. DOI: 10.1109/34084POWERI.2014.7117650
  6. I. Y. Choi, J. A. Kim, "A Study on Turbine Bypass System in a 500MW Rated Coal Fired Supercritical Thermal Power Plant with Sliding Pressure Operation," in Proc. of the 2008 KIEE Conference, pp.1663-1664, 2008.
  7. S. I. Seo, H. Y. Park, S. N. Lee, "Computational Studies on the Combustion and Thermal Performance of the Coal Fired Utility Boiler," Korean Journal of Air-Conditioning and Refrigeration Engineering, vol.21, no.3, pp.157-166, 2009.
  8. Y. D. Son, J. J. Jin, "A Nonlinear PD Controller Design and Its Application to MOV Actuators," Studies in Informatics and Control, vol.28, no.1, pp.5-12, 2019. https://doi.org/10.24846/v28i1y201901