Optimal Design of Steam Turbine System for Advanced Ultra-supercritical Double Reheat Coal-fired Units

doi:10.12096/j.2096-4528.pgt.21053

Abstract

Abstract:

In view of the current situation of backpressure extraction steam turbine (BEST) regenerative system design for advanced ultra-supercritical coal-fired units, the influence of BEST on energy consumption of 700℃ coal-fired units with single and double reheat system was compared and analyzed. Based on parameter matching and system optimization method of steam turbine flow and regenerative system, the idea of optimizing regenerative system from the system perspective was put forward. The results show that the coal consumption of 700℃ double reheat coal-fired units with BEST is lower than that of single reheat units, and the coal saving advantage is more obvious at low load. The coal saving is 11.7g/(kW·h) at 40% load. 700℃ double reheat units with BEST is more economical for peak adjustment than single reheat units, and 700℃ single reheat units with BEST is more suitable for high load operation units. With the reduction of load, the extraction superheat of 700℃ double reheat units with BEST increases continuously, therefore, the extraction position of BEST can be adjusted backward to match the minimum coal consumption. In addition, a method of matching the extraction parameters of the regenerative system with the flow parameters of the steam turbine was proposed to optimize the whole system of the units. Based on this method, the BEST can be cancelled, but the load distribution and flow design of the three cylinders of the steam turbine need to be redesigned.

Key words: advanced ultra-supercritical coal-fired units, steam turbine, double reheat, regenerative system

CLC Number:

TK26

Jing WANG, Jinfu YANG, Liqiang DUAN, Liguo TIAN, Yutian JING, Ming YANG. Optimal Design of Steam Turbine System for Advanced Ultra-supercritical Double Reheat Coal-fired Units[J]. Power Generation Technology, 2021, 42(4): 480-488.

Figures/Tables 13

References 23

1	胡鞍钢. 中国实现2030年前碳达峰目标及主要途径[J]. 北京工业大学学报(社会科学版), 2021, 21 (3): 1- 8.
	HU A G . China's goal of achieving carbon peak by 2030 and its main approaches[J]. Journal of Beijing University of Technology (Social Sciences Edition), 2021, 21 (3): 1- 8.
2	全球能源互联网发展合作组织. 中国2030年前碳达峰研究报告[EB/OL]. (2021-03-18)[2021-05-01]. https://max.book118.com/html/2021/0319/7200106100003101.shtm.
	Global Energy Internet Development Cooperation Organization. China's carbon peak research report before 2030[EB/OL]. (2021-03-18)[2021-05-01]. https://max.book118.com/html/2021/0319/7200106100003101.shtm.
3	龙辉, 黄晶晶. "十三五"燃煤发电设计技术发展方向分析[J]. 发电技术, 2018, 39 (1): 13- 17.
	LONG H , HUANG J J . Development direction analysis of coal-fired power units' design technology during the 13th Five-Year Plan[J]. Power Generation Technology, 2018, 39 (1): 13- 17.
4	王林, 伍刚, 张亚夫, 等. 1000MW深度调峰机组热力系统优化研究[J]. 发电技术, 2019, 40 (3): 265- 269.
	WANG L , WU G , ZHANG Y F , et al. Thermodynamic system optimization research on 1000MW deep peak-regulating unit[J]. Power Generation Technology, 2019, 40 (3): 265- 269.
5	刘入维, 肖平, 钟犁, 等. 700℃超超临界燃煤发电技术研究现状[J]. 热力发电, 2017, 46 (9): 1- 7. DOI
	LIU R W , XIAO P , ZHONG L , et al. Research progress of advanced 700℃ ultra-supercritical coal-fired power generation technology[J]. Thermal Power Generation, 2017, 46 (9): 1- 7. DOI
6	段立强, 孙婧, 王振. 二次再热机组不同抽汽过热度热能利用方案性能比较[J]. 工程热物理学报, 2019, 40 (12): 2757- 2762.
	DUAN L Q , SUN J , WANG Z . Performance comparison of thermal energy utilization schemes of the extractions superheating degree for a double reheat coal-fired power plant[J]. Journal of Engineering Thermophysics, 2019, 40 (12): 2757- 2762.
7	段立强, 孙婧. 集成回热式汽轮机的超超临界二次再热机组设计优化[J]. 华北电力大学学报, 2019, 46 (3): 80- 89. DOI
	DUAN L Q , SUN J . Design optimization of ultra-supercritical reheating coal-fired power plant integrated with regenerative steam turbine[J]. Journal of North China Electric Power University, 2019, 46 (3): 80- 89. DOI
8	程辉. 超超临界二次再热1000MW机组回热系统优化[J]. 能源科技, 2020, 18 (2): 47- 50.
	CHENG H . Optimization of regenerative system of 1000MW ultra supercritical double reheat unit[J]. Energy Science and Technology, 2020, 18 (2): 47- 50.
9	邓攀, 王亚军. BEST技术用于超超临界二次再热机组的可行性分析[J]. 中国电力, 2018, 51 (7): 84- 89. DOI
	DENG P , WANG Y J . Feasibility analysis on BEST technology for ultra supercritical units with double-reheat cycle[J]. Electric Power, 2018, 51 (7): 84- 89. DOI
10	LI Y Y , ZHOU L Y , XU G , et al. Thermodynamic analysis and optimization of a double reheat system in an ultra-supercritical power plant[J]. Energy, 2014, 74, 202- 214. DOI
11	XU G , ZHOU L Y , ZHAO S F , et al. Optimum superheat utilization of extraction steam in double reheat ultra-supercritical power plants[J]. Applied Energy, 2015, (160): 863- 872.
12	周云龙, 杨美, 王迪. 1000MW高超超临界二次再热系统优化[J]. 中国电机工程学报, 2018, 38 (S1): 137- 141.
	ZHOU Y L , YANG M , WANG D . Optimization of 1000MW high ultra-supercritical double-reheat system[J]. Proceedings of the CSEE, 2018, 38 (S1): 137- 141.
13	YANG M , ZHOU Y L , WANG D , et al. Thermodynamic cycle analysis and optimization to improve efficiency in a 700℃ ultra-supercritical double reheat system[J]. Journal of Thermal Analysis and Calorimetry, 2020, 141, 83- 94. DOI
14	税杨浩, 刘强, 张磊, 等. 650℃超超临界1000MW机组回热系统的参数优化[J]. 工程热物理学报, 2020, 41 (1): 89- 94.
	SHUI Y H , LIU Q , ZHANG L , et al. Parametric optimization of a regenerative system for a 650℃ ultra-supercritical steam turbine[J]. Journal of Engineering Thermophysics, 2020, 41 (1): 89- 94.
15	LIN X L , LI Q L , WANG L K , et al. Thermo-economic analysis of typical thermal systems and corresponding novel system for a 1000 MW double reheat ultra-supercritical thermal power plant[J]. Energy, 2020, 201, 117560. DOI
16	阳虹, 余炎, 范世望, 等. 梯次循环(EC)在超超临界1000 MW机组工程应用与分析[J]. 热力发电, 2019, 48 (12): 129- 133.
	YANG H , YU Y , FAN S W , et al. Application and analysis of echelon cycle in ultra supercritical 1000MW unit[J]. Thermal Power Generation, 2019, 48 (12): 129- 133.
17	王婧, 段立强, 杨金福, 等. 700℃一次再热超超临界机组回热系统节能优化[C]//中国工程热物理学学术会议, 上海, 2020.
	WANG J, DUAN L Q, YANG J F, etc. Energy saving optimization study on regenerative system of 700℃ coal-fired power generation system with single reheat system[C]//China Engineering Thermophysics Conference, Shanghai, 2020.
18	杨金福, 张忠孝, 韩东江, 等. 新型超临界参数燃煤发电系统结构设计技术[J]. 发电技术, 2019, 40 (6): 555- 563.
	YANG J F , ZHANG Z X , HAN D J , et al. New supercritical parameter coal-fired power generation system structure design technology[J]. Power Generation Technology, 2019, 40 (6): 555- 563.
19	宋之平. 单耗分析的理论和实施[J]. 中国电机工程学报, 1992, 12 (4): 15- 21.
	SONG Z P . Consumption rate analysis: theory and practice[J]. Proceedings of the CSEE, 1992, 12 (4): 15- 21.
20	刁美玲, 唐春丽, 朱信, 等. 超超临界二次再热机组热经济性及技术经济性分析[J]. 热力发电, 2017, 46 (8): 23- 29.
	DIAO M L , TANG C L , ZHU X , et al. Thermo-economic and techno-economic analysis on an ultra-supercritical unit with double-reheat cycle[J]. Thermal Power Generation, 2017, 46 (8): 23- 29.
21	林万超. 火电厂热系统节能理论[M]. 西安: 西安交通大学出版社, 1994: 191- 203.
	LIN W C . Energy-saving theory of thermal power plant thermal system[M]. Xi'an: Xi'an Jiaotong University Press, 1994: 191- 203.
22	严俊杰, 邵树峰, 李杨, 等. 二次再热超临界机组热力系统经济性定量分析方法[J]. 中国电机工程学报, 2004, 24 (1): 186- 190. DOI
	YAN J J , SHAO S F , LI Y , et al. A method for analysis the economics of a thermal system in a supercritical pressure power unit with double reheat cycles[J]. Proceedings of the CSEE, 2004, 24 (1): 196- 190. DOI
23	邵树峰, 严俊杰, 刘继平, 等. 二次再热机组热力系统的定量分析方法[J]. 西安交通大学学报, 2003, 37 (11): 1137- 1141. DOI
	SHAO S F , YAN J J , LIU J P , et al. Thermo-economics analysis method of thermal system for power unit with double reheat[J]. Journal of Xi'an Jiaotong University, 2003, 37 (11): 1137- 1141. DOI

抽汽级数	抽汽压力/MPa	抽汽温度/℃	过热度/℃	抽汽级数	抽汽压力/MPa	抽汽温度/℃	过热度/℃
1	10.240	485.05	172.47	6	0.760	169.38	1.29
2	7.570	442.23	151.20	7	0.320	250.46	114.93
3	4.140	359.07	106.68	8	0.100	140.01	39.96
4	2.610	299.57	73.44	9	0.040	75.58	0.00
5	1.640	247.32	44.91	10	0.017	56.89	0.00

抽汽级数	抽汽压力/MPa	抽汽温度/℃	过热度/℃	抽汽级数	抽汽压力/MPa	抽汽温度/℃	过热度/℃
1	10.240	485.05	172.47	6	0.760	169.38	1.29
2	7.570	442.23	151.20	7	0.320	250.46	114.93
3	4.140	359.07	106.68	8	0.100	140.01	39.96
4	2.610	299.57	73.44	9	0.040	75.58	0.00
5	1.640	247.32	44.91	10	0.017	56.89	0.00

抽汽级数	抽汽压力/MPa	抽汽温度/℃	过热度/℃
1	8.850	457.80	155.80
2	6.000	402.40	126.90
3	3.700	336.40	90.70
4	2.500	287.40	63.50
5	1.560	234.00	33.85
6	0.810	170.80	0.80
7	0.440	147.00	0.00
8	0.130	354.90	247.90
9	0.064	262.90	175.30
10	0.024	152.20	88.20

抽汽级数	抽汽压力/MPa	抽汽温度/℃	过热度/℃
1	8.850	457.80	155.80
2	6.000	402.40	126.90
3	3.700	336.40	90.70
4	2.500	287.40	63.50
5	1.560	234.00	33.85
6	0.810	170.80	0.80
7	0.440	147.00	0.00
8	0.130	354.90	247.90
9	0.064	262.90	175.30
10	0.024	152.20	88.20

工况	发电煤耗		节煤量
工况	700 ℃一次再热机组	700 ℃二次再热机组	节煤量
THA	233.66	233.50	0.15
75%THA	241.67	240.49	1.17
50%THA	253.37	246.14	7.23
40%THA	261.72	250.02	11.70