基于循环水泵变频的1 000 MW超超临界机组冷端综合优化

doi:10.12096/j.2096-4528.pgt.23024

摘要/Abstract

摘要：

目的在碳达峰、碳中和背景下，火电机组节能提效是电力行业低碳转型的关键，通过冷端优化提高机组的运行经济性是行之有效的方法之一，因此，对冷端系统进行宽负荷优化非常必要。方法以宁海电厂1 000 MW机组的冷端系统为研究对象，建立了湿式自然通风冷却塔的计算模型，开发了对应的软件模块，可根据环境温度、湿度和大气压力数据，实现冷却塔-循环泵组-凝汽器-汽轮机组的耦合计算。以实际环境参数和运行负荷为变量，开展了冷却塔运行曲线、循环水泵泵组工频与变频运行对比、机组冷端综合优化等研究。结果循环水泵变频的最大节能率接近50%；当环境温度约低于31 ℃时，可以通过调整循环水流量降低煤耗率；环境温度越低，煤耗率收益越大，平均煤耗率可降低2.0 g/(kW⋅h)以上，但不同工况的煤耗收益差异非常大。结论研究结果可为机组冷端优化节能提供参考。

关键词: 碳达峰, 碳中和, 超超临界, 循环水泵, 变频, 冷端优化, 冷却塔, 凝汽器

Abstract:

Objectives In the context of carbon peaking and carbon neutrality, the energy saving and efficiency improvement of thermal power units is the key to the low-carbon transformation of the power industry. Moreover, the implementation of cold end optimization to improve the operating economy of the unit is one of the effective methods, Therefore, it is necessary to optimize the cold end system with wide load. Methods This paper took the cold end system of the 1000 MW unit of Ninghai power plant as the research object, the calculation model of the wet natural ventilation cooling tower was established, and the corresponding software module was developed, which can realize the coupling calculation of the cooling tower-circulating pump group-condenser-steam turbine unit according to the ambient temperature, humidity and atmospheric pressure data. Taking the actual environmental parameters and operating load as variables, the operation curve of the cooling tower, the comparison between the constant frequency and the frequency conversion operation of the circulating water pump group, and the comprehensive optimization of the cold end of the unit were carried out. Results The maximum energy saving rate of pump frequency conversion is close to 50%. When the ambient temperature is about 31 ℃, the coal consumption rate can be reduced by adjusting the circulating water flow. The lower the ambient temperature is, the greater the coal consumption rate benefit is, the average coal consumption rate can be reduced by more than 2.0 g/(kW⋅h). However, the coal consumption income of different working conditions varies greatly. Conclusions The research results can provide reference for optimizing energy conservation at the cold end of the unit.

Key words: carbon peaking, carbon neutrality, ultra supercritical, circulating water pump, frequency conversion, cold end optimization, cooling tower, condenser

中图分类号:

TK 12

张东青, 金铁铮, 张磊. 基于循环水泵变频的1 000 MW超超临界机组冷端综合优化[J]. 发电技术, 2024, 45(6): 1095-1104.

Dongqing ZHANG, Tiezheng JIN, Lei ZHANG. Comprehensive Optimization of the Cold End of 1 000 MW Ultra-Supercritical Unit Based on Pump Frequency Conversion[J]. Power Generation Technology, 2024, 45(6): 1095-1104.

图/表 10

参考文献 27

1	中能传媒研究院．中国能源大数据报告(2022)[R]．北京：中能传媒研究院，2022．
	Zhongneng Media Research Institute ．China energy big data report (2022)[R]．Beijing：Zhongneng Media Research Institute，2022．
2	冯伟忠，李励．“双碳”目标下煤电机组低碳、零碳和负碳化转型发展路径研究与实践[J]．发电技术，2022，43(3)：452-461． doi:10.12096/j.2096-4528.pgt.22061
	FENG W Z， LI L ．Research and practice on development path of low-carbon， zero-carbon and negative carbon transformation of coal-fired power units under “double carbon” targets[J]．Power Generation Technology，2022，43(3)：452-461． doi:10.12096/j.2096-4528.pgt.22061
3	朱法华，徐静馨，潘超，等．煤电在碳中和目标实现中的机遇与挑战[J]．电力科技与环保，2022，38(2)：79-86．
	ZHU F H， XU J X， PAN C，et al ．Opportunities and challenges of coal power industry in the achievement of car-bon neutrality goal[J]．Electric Power Technology and Environmental Protection，2022，38(2)：79-86．
4	高恬，牛东晓，纪正森，等．双碳目标下基于分解-集成的月度煤电需求预测研究[J]．智慧电力，2022，50(9)：22-29．
	GAO T， NIU D X， JI Z S，et al ．Monthly coal power demand forecasting based on decomposition-integration under carbon peak & carbon neutrality goals[J]．Smat Power，2022，50(9)：22-29．
5	张兴平，何澍，王泽嘉，等．不同新能源渗透率下燃煤机组行为策略分析[J]．电力建设，2022，43(5)：9-17． doi:10.12204/j.issn.1000-7229.2022.05.002
	ZHANG X P， HE S， WANG Z J，et al ．Behavior strategy of coal-fired units under different new energy penetration rate[J]．Electric Power Construction，2022，43(5)：9-17． doi:10.12204/j.issn.1000-7229.2022.05.002
6	李政，陈思源，董文娟，等．碳约束条件下电力行业低碳转型路径研究[J]．中国电机工程学报，2021，41(12)：3987-4000． doi:10.13334/j.0258-8013.pcsee.210671
	LI Z， CHEN S Y， DONG W J，et al ．Low carbon transition pathway of power sector under carbon emission constraints[J]．Proceedings of the CSEE，2021，41(12)：3987-4000． doi:10.13334/j.0258-8013.pcsee.210671
7	周鑫，程松，任景，等．含储热型热电联产机组的电力系统源荷联合优化调峰方法[J]．电力科学与技术学报，2023，38(5)：12-21．
	ZHOU X， CHEGN S， REN J，et al ．A source-load joint optimization peak regulation method of power system with heat storage combined heat and power units[J]．Journal of Electric Power Science and Technology，2023，38(5)：12-21．
8	于国强，刘克天，胡尊民，等．大规模新能源并网下火电机组深度调峰优化调度[J]．电力工程技术，2023，42(1)：243-250． doi:10.12158/j.2096-3203.2023.01.029
	YU G Q， LIU K T， HU Z M，et al ．Optimal scheduling of deep peak regulation for thermal power units in power grid with large-scale new energy[J]． Electric Power Engineering Technology，2023，42(1)：243-250． doi:10.12158/j.2096-3203.2023.01.029
9	李秀云，严俊杰，林万超．火电厂冷端系统评价指标及诊断方法的研究[J]．中国电机工程学报，2001，21(9)：94-98．
	LI X Y， YAN J J， LIN W C ．Study on thermo-economics diagnosis method and index evaluation system for the cold-end system in steam power unit[J]．Proceedings of the CSEE，2001，21(9)：94-98．
10	闫桂焕，顾昌，郑李坤．300 MW机组循环水系统优化运行的研究[J]．汽轮机技术，2002，44(6)：345-347．
	YAN G H， GU C， ZHENG L K ．Research on optimal operation of circulating water system of 300 MW unit[J]．Turbine Technology，2002，44(6)：345-347．
11	赵斌，刘玲，张文兵．汽轮机冷端优化的研究[J]．热力透平，2007，36(1)：19-23． doi:10.3969/j.issn.1672-5549.2007.01.005
	ZHAO B， LIU L， ZHANG W B ．Optimization for steam turbine cold end system[J]．Thermal Turbine，2007，36(1)：19-23． doi:10.3969/j.issn.1672-5549.2007.01.005
12	马立恒，王运民．火电厂凝汽式汽轮机冷端运行优化研究[J]．汽轮机技术，2010，52(2)：137-140．
	MA L H， WANG Y M ．Study on the running optimization for condensing steam turbine cold end in thermal power plant[J]．Turbine Technology，2010，52(2)：137-140．
13	王玮，曾德良，杨婷婷，等．基于凝汽器压力估计算法的循环水泵最优运行[J]．中国电机工程学报，2010，30(14)：7-12．
	WANG W， ZENG D L， YANG T T，et al ．The optimum running of circulating water pumps based on estimated condenser pressure[J]．Proceedings of the CSEE，2010，30(14)：7-12．
14	赵伟光，刘明远，王丰，等．国产超临界600 MW汽轮机冷端优化运行方式的确定[J]．东北电力技术，2015，36(6)：1-3．
	ZHAO W G， LIU M Y， WANG F，et al ．Determination of cold-end optimization operation for domestic supercritical 600 MW steam turbine[J]．Northeast Electric Power Technology，2015，36(6)：1-3．
15	刘吉臻，王玮，曾德良，等．火电机组定速循环水泵的全工况运行优化[J]．动力工程学报，2011，31(9)：682-688．
	LIU J Z， WANG W， ZENG D L，et al ．Operation optimization of constant-speed circulating water pumps in a thermal power plant under full conditions[J]．Journal of Chinese Society of Power Engineering，2011，31(9)：682-688.
16	黄新元，赵丽，安越里，等．火电厂单元制循环水系统离散优化模型及其应用[J]．热能动力工程，2004，19(3)：302-305．
	HUANG X Y， ZHAO L， AN Y L，et al ．A discrete optimized model for the monobloc configured circulating water system of a thermal power plant and its applications[J]．Journal of Engineering for Thermal Energy and Power，2004，19(3)：302-305．
17	陈云，李森，赵元宾．基于凝汽器负挖的电厂直流式冷端系统优化研究[J]．发电技术，2022，43(4)：655-663．
	CHEN Y， LI S， ZHAO Y B ．Optimization study of power plant direct flow cold-end subsystem based on negative digging[J]．Power Generation Technology，2022，43(4)：655-663．
18	刘桂生，马骏驰，丁平，等．循环水泵电动机双速改造[J]．热力发电，2008，37(2)：66-67．
	LIU G S， MA J C， DING P，et al ．Retrofitting electric motor of circulating water pump into a double-speed one[J]．Thermal Power Generation，2008，37(2)：66-67．
19	张营．循环水泵双速改造并联运行经济性分析[J]．华电技术，2009，31(11)：3-5．
	ZHANG Y ．Economical analysis of two-speed reformation and parallel operation of water circulating pumps[J]．Huadian Technology，2009，31(11)：3-5．
20	李放．350 MW 机组中循环水泵电机高低速改造研究[D]．长春：吉林大学，2016．
	LI F ．Research on high-low speed transformation of middle circulation water pump motor in 350 MW unit[D]．Changchun：Jilin University，2016，2016
21	瞿伟明．600 MW机组循环水泵变频改造后运行方式优化[J]．发电设备，2012，26(3)：183-185．
	QU W M ．Operation optimization of the circulating pump for a 600 MW power unit after its frequency conversion retrofit[J]．Power Equipment，2012，26(3)：183-185．
22	瞿伟明．600 MW机组循环水泵高压变频调速系统的工程应用及效果分析[D]．上海：上海交通大学，2012．
	QU W M ．Engineering application and effect analysis of high-pressure frequency conversion speed regulation system for circulating water pump of 600 MW unit[D]．Shanghai：Shanghai Jiaotong University，2012．
23	沈发荣，赵明，崔海波，等．循环水泵计算模型及节能分析[J]．热力发电，2018，47(3)：12-17．
	SHEN F R， ZHAO M， CUI H B，et al ．Calculation model and energy saving analysis of circulating water pump[J]．Thermal Power Generation，2018，47(3)：12-17．
24	朱艳梅，李士超．循环水泵采用变频泵及双速泵的调节研究[J]．电力勘测设计，2020(7)：47-53．
	ZHU Y M， LI S C ．Study of circulating water pump with variable frequency pump and dual rate pump[J]．Electric Power Survey & Design，2020(7)：47-53．
25	张磊，张俊杰，王顺森，等．煤基分布式能源技术研究与经济性分析[J]．节能技术，2021，39(5)：403-406．
	ZHANG L， ZHANG J J， WANG S S，et al ．Coal-based distributed energy technology research and economic analysis[J]．Energy Conservation Technology，2021，39(5)：403-406．
26	梁占伟，张磊，徐亚涛，等．高背压供热机组供热温度特性与㶲分析[J]．热力发电，2020，49(1)：17-25．
	LIANG Z W， ZHANG L， XU Y T，et al ．Heating temperature characteristics and exergy analysis for high back pressure heating unit[J]．Thermal Power Generation，2020，49(1)：17-25．
27	梁占伟，杨承刚，张磊，等．基于单耗理论的抽汽耦合高背压供热优化[J]．中国电力，2019，52(12)：171-178．
	LIANG Z W， YANG C G， ZHANG L，et al ．Optimization of steam extraction combined high back pressure heating based on specific consumption theory[J]．Electric Power，2019，52(12)：171-178．

入塔水温	出塔水温
26.0	22.05
26.5	22.25
27.0	22.44
27.5	22.62
28.0	22.80
28.5	22.97
29.0	23.14
29.5	23.31
30.0	23.47
30.5	23.62
31.0	23.77
31.5	23.91
32.0	24.05
32.5	24.18
33.0	24.31
33.5	24.44
34.0	24.55
34.5	24.67
35.0	24.77

入塔水温	出塔水温
26.0	22.05
26.5	22.25
27.0	22.44
27.5	22.62
28.0	22.80
28.5	22.97
29.0	23.14
29.5	23.31
30.0	23.47
30.5	23.62
31.0	23.77
31.5	23.91
32.0	24.05
32.5	24.18
33.0	24.31
33.5	24.44
34.0	24.55
34.5	24.67
35.0	24.77

循环水量/(t/h)	出塔水温/℃
18 600	21.86
19 600	22.07
20 600	22.26
21 600	22.46
22 600	22.64
23 600	22.82
24 600	22.99
25 600	23.16
26 600	23.32
27 600	23.47

循环水量/(t/h)	出塔水温/℃
18 600	21.86
19 600	22.07
20 600	22.26
21 600	22.46
22 600	22.64
23 600	22.82
24 600	22.99
25 600	23.16
26 600	23.32
27 600	23.47

循环水流量/(t/h)	2机2定频泵	2机1变频泵 1定频泵		2机2变频泵
循环水流量/(t/h)	功耗/kW	功耗/kW	变频比	功耗/kW	变频比
42 000	—	—	—	2 640	0.800
44 000	—	—	—	2 810	0.815
46 000	—	—	—	2 992	0.833
48 000	4 988	3 256	0.758	3 183	0.851
50 000	5 005	3 404	0.782	3 385	0.870
52 000	5 017	3 575	0.809	3 598	0.890
54 000	5 023	3 769	0.839	3 821	0.909
56 000	5 009	3 895	0.871	4 053	0.930
58 000	4 966	4 218	0.906	4 293	0.950
60 000	4 903	4 463	0.942	4 541	0.970
62 000	4 828	4 722	0.979	4 798	0.989
64 000	4 862	4 998	1.000	5 068	1.000