Investigations of Operational Flexibility of Coal-Fired Thermal Power Plants

Öz

This study is aimed to change the operational activities of coal fired power plants to effectively increase its flexibility. With the large scale increase of generation in renewable energy in recent years, the need to develop skills in the area of competitivity in thermal power plants has emerged. In addition, since renewable energy can have instantaneous changes in production, there is more work needed to be done for thermal power plants that balance the grid. Due to this reason, increasing the flexibility of thermal power plants is examined under 4 main headings: Working under minimum load, fast load ramp up/down, start-up procedure optimization and primary and secondary support capabilities. As a result of the 4 different studies in the flexibility categories, the power plant has been successful without exceeding the limit values. The minimum load value which was previously determined as % 40 was revised to % 30, the primary and secondary frequency tests were also successful and the load ramp up/down values were improved to 20MW/min. Finally, the start-up program has been developed to perform with minimum auxiliary fuel. 

Anahtar Kelimeler

• : Flexibility,thermal power plant,working conditions,minumum load,fast load ramp up/down

Kömür Yakıtlı Termik Santralin Çalışma Esnekliğinin İncelenmesi

Öz

Bu çalışmada kömür yakıtlı termik santrallerin operasyonel faaliyetlerde değişikliğe gidilerek esnekliğinin artırılması amaçlanmıştır. Son yıllarda yenilenebilir kaynaklı enerji üretiminin büyük ölçüde artmasıyla termik santrallerin yenilenebilir kaynaklı enerji üretimiyle rekabet yeteneğinin geliştirilmesi ihtiyacı doğmuştur. Ayrıca yenilenebilir kaynaklı enerji üretimi anlık değişimler gösterebildiği için termik santrallere şebeke dengeleme yönünden daha çok iş düşmektedir. Bu sebepten dolayı, termik santrallerin operasyonel esnekliğinin artırılması 4 ana başlık altında incelenmiştir: minumum yükte çalışma, hızlı yük alma ve atma, devreye alma prosedürü optimizasyonu ve son olarak primer ve sekonder destek kabiliyetlerinin artırılması çalışmalarını kapsamaktadır. Yapılan çalışmalar sonucunda 4 farklı esneklik kategorisinde santral sınır değerlerin dısına çıkmadan başarılı olmuştur. Daha önce % 40 belirlenen minumum yük değeri % 30 değerine revize edilmiş ayrıca primer ve sekonder frekans destek testlerinden başarıyla geçmiş bununla beraber yük alma/atma hızı 20 MW/dk değerine iyileştirilmiştir. Son olarak, devreye alma programı optimize edilmiş minimum yardımcı yakıtla devreye alacak şekilde geliştirilmiştir.

Anahtar Kelimeler

• Esneklik,termik santral,çalışma rejimleri,minimum yük,yük alma/atma hızı

Kaynakça

1. [1]. Zhao, S., Ge, Z., Sun, J., Ding, Y., Yang, Y., ‘‘Comparative study of flexibility enhancement technologies for the coal-fired combined heat and power plant’’, Energy Conversion and Management, 184: 15-23, (2019).
2. [2]. Zhao, Y., Liu, M., Wang, C., Li, X., Chong, D., Yan, J., ‘‘Increasing operational flexibility of supercritical coal-fired power plants by regulating thermal system configuration during transient processes’’, Applied Energy 225: 2375-2386, (2018).
3. [3]. Wang, J., You, S., Zong, Y., Traholt, C., Dong, Zhou, Y., ‘‘Flexibility of combined heat and power plants: A review of technologies and operation strategies’’, Applied Energy, 252: 113445 (2019) .
4. [4]. Liu, M.,Wang, S., Zhao, Y., Tang, H., Yan, J., ‘‘Heatepower decoupling technologies for coal-fired CHP plants:Operation flexibility and thermodynamic performance’’, Energy, 188:116074, (2019).
5. [5]. https://www.epias.com.tr/‘‘Merit order sıralaması’’,(2020).
6. [6]. Dotzauer, M., Pfeiffer, D., Lauer, M., Pohl, M., Mauky, E., Bear, K., Sonnleitner, M., Zeorner, W., Huddle, J., Schwarz, B., Fbauer, B., Dahmen, M. Rieke, C., Herbert, J., Threan, D., ‘‘How to measure flexibility e Performance indicators for demand driven power generation from biogas plants’’, Renewable Energy, 134:135-146, (2019).
7. [7]. Hentschel, J., Babić, U., Spliethoff, H. ‘‘A parametric approach for the valuation of power plant flexibility options’’, Energy Reports, 2:40-47, (2016).
8. [8]. Salazar, MAG., Kirsten, T., Prchlik, L., ‘‘Review of the operational flexibility and emissions of gas- and coal-fired power plants in a future with growing renewables’’, Renewable and Sustainable Energy Reviews, 82:1497-1513, (2018).

9. [9]. Richter, M., Oeljeklaus, G., Görner, K., ‘‘Improving the load flexibility of coal-fired power plants by the integration of a thermal energy storage’’, Applied Energy, 236:607-621, (2019).
10. [10]. Sun, Y., Wang, L., Xu, C., Van herle., J., Marechal, F., Yang, Y., ‘‘Enhancing the operational flexibility of thermal power plants by coupling high-temperature power-to-gas ’’, Applied Energy, 263:114608, (2020).
11. [11]. Zhao, Y., Wang, C., Liu, M., Chong, D., Yan, J., ‘‘Improving operational flexibility by regulating extraction steam of high pressure heaters on a 660MW supercritical coal-fired power plant: A dynamic simulation’’, Applied Energy, 212:1295-1309, (2018).
12. [12]. Tontu, M., Şahin, B., Bilgili, M., ‘‘Using energy and exergy analysis to compare different coal-fired power plants’’, Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, in press (2019).
13. [13]. Glensk, B.,Madlener, R., ‘‘Evaluating the enhanced flexibility of lignite-fired power plants: A realoptions analysis’’, Energy Conversion and Management, 177:737-749, (2018).
14. [14]. Garbrecht, O, Bieber, M., Kneer, R., ‘‘Increasing fossil power plant flexibility by integrating molten-salt thermal storage’’, Energy, 876-883, (2017).
15. [15]. Li, D., Wang, J., ‘‘Study of supercritical power plant integration with high temperature thermal energy storage for flexible operation’’, Journal of Energy Storage, 20:140-152, (2018).
16. [16]. http://www.epdk.org.tr//‘‘Elektrik şebeke yönetmeliği’’,(2020).