高背压供热汽轮机低压部分性能优化

doi:10.16085/j.issn.1000-6613.2019-0428

摘要/Abstract

摘要：

汽轮机高背压供热方式可回收低压缸排汽余热，扩大机组的供热能力，减少高品位抽汽造成的可用能损失，能源转换效率高。供热季运行背压高，低压转子采用了双转子互换技术，低压转子结构的变化使低压部分热力特性发生变化。本文建立了300MW等级高背压供热机组热力系统模型，计算并分析抽汽参数变化对低压加热器附加单耗的影响，并通过参数优化降低供热季低压加热器附加单耗。获得五段和六段抽汽压力优化结果，降低了传热端差，使各级低压加热器温升分配合理，优化后机组发电功率增加507kW，?损减小575.5kW，整体附加单耗下降0.3121g/(kW·h)。以此为基础，进行高背压供热机低压通流部分热力计算，重新分配低压缸各压力级焓降，提高低压缸的通流效率。结果表明：通过对低压回热系统和通流部分优化，低压缸内效率提高至0.9250，机组发电功率增加3068.49kW。

关键词: 高背压供热, 回热系统, 单耗分析, 通流部分, ?, 模型, 优化

Abstract:

High back-pressure(HBP)heating method can expand the heating capacity of the unit by recovering the exhaust heat and reducing the available energy losses of the extract steam, which is of high energy conversion efficiency. The low-pressure rotor adopts the double-rotor interchange technology and the back-pressure is high during the heating season, the low-pressure cylinder’s thermal characteristics are changed. Therefore, a thermodynamic system model for a 300MW high back-pressure heating unit was established, the effect of the extraction parameter change on the additional unit consumption of the low-pressure heater was calculated and analyzed, and the additional unit consumption during the heating season through parameter optimization was reduced. The optimal optimization effect was obtained when the extraction pressures of the five sections and six sections were 0.3591MPa and 0.1559MPa, and the temperature rise of the low-pressure heaters at all levels was reasonable because of the lower heat transfer end difference. After optimization, the power generation of the unit was increased by 507kW, the exergy loss was reduced by 575.5kW, and the additional unit consumption was reduced by 0.3121g/(kW·h). Based on this, the low-pressure cylinder’s flow section of the high-pressure heating unit was subjected to thermal calculation, the pressure drop of each low-pressure cylinder’ blades was re-allocated to increase the flow efficiency of the low-pressure cylinder. The results showed that by optimizing the low-pressure heat recovery system and the through-flow part, the efficiency of the low-pressure cylinder increases to 0.9250, and the unit output increases by 3068.49kW.

Key words: high back-pressure heating, regenerative feed system, specific consumption analysis, flow part, exergy, model, optimization

中图分类号:

TM621

戈志华,张尤俊,熊念,赵世飞. 高背压供热汽轮机低压部分性能优化[J]. 化工进展, 2019, 38(12): 5264-5270.

Zhihua GE,Youjun ZHANG,Nian XIONG,Shifei ZHAO. Optimization of low-pressure flow part of high back-pressureheating steam turbine[J]. Chemical Industry and Engineering Progress, 2019, 38(12): 5264-5270.

图/表 13

参考文献 23

1	戈志华, 陈玉勇, 李沛峰, 等. 基于当量抽汽压力的大型热电联产供热模式研究[J]. 动力工程学报, 2014, 34(7): 569-575.
	GE Zhihua, CHEN Yuyong, LI Peifeng, et al. Study on heating mode of a large heat and power cogeneration unit based on equivalent extraction pressure[J]. Journal of Chinese Society of Power Engineering, 2014, 34(7): 569-575.
5	石德静, 姜维军. 300MW汽轮机高背压循环水供热技术研究及应用[J]. 山东电力技术, 2015, 42(4): 8-11.
	SHI Dejing, JIANG Weijun. Circulating water heating technology for a 300MW steam turbine with high back-pressure[J]. Shandong Electric Power, 2015, 42(4): 8-11.
6	邵建明, 陈鹏帅, 周勇. 300MW湿冷汽轮机双转子互换高背压供热改造应用[J]. 能源研究与信息, 2014, 30(2): 100-103.
	SHAO Jianming, CHEN Pengshuai, ZHOU Yong. An application of double-rotor interchange technology in the retrofit for a high back pressure heat supply system with 300MW condensing turbine[J]. Energy Research and Information, 2014, 30(2): 100-103.
2	戈志华, 杨佳霖, 何坚忍, 等. 大型纯凝汽轮机供热改造节能研究[J]. 中国电机工程学报, 2012, 32(17): 25-30.
	GE Zhihua, YANG Jialin, HE Jianren, et al. Energy saving research of heating retrofitting for large scale condensing turbine[J]. Proceedings of the CSEE, 2012, 32(17): 25-30.
7	国内首台350MW间冷机组高背压科技项目通过验收[J]. 发电与空调,2017, 38(4): 32.
	The first domestic high back-pressure technology project for 350MW intercooler units passed the acceptance test[J]. Power Generation & Air-Conditioning,2017, 38(4): 32.
3	成渫畏, 王学栋, 宋昂. 首台300MW汽轮机循环水供热改造技术与经济指标分析[J]. 发电与空调, 2016, 37(1): 6-10.
	CHENG Xiewei, WANG Xuedong, SONG Ang. Transformation technology and economic indicators analysis of the first 300MW steam turbine supplying heat using high-temperature circulating water[J]. Power Generation & Air Conditioning, 2016, 37(1): 6-10.
8	史敬杰, 张晓静. 高背压供热技术在300MW空冷供热机组的应用[J]. 科技展望, 2015, 25(28): 62,64.
	SHI Jingjie, ZHANG Xiaojing. Application of high back pressure heating technology in 300MW air-cooled heating units[J]. Science & Technology Outlook, 2015, 25(28): 62,64.
4	戈志华, 孙诗梦, 万燕, 等. 大型汽轮机组高背压供热改造适用性分析[J]. 中国电机工程学报, 2017, 37(11): 3216-3222, 3377.
	GE Zhihua, SUN Shimeng, WAN Yan, et al. Applicability analysis of high back-pressure heating retrofit for large-scale steam turbine units[J]. Proceedings of the CSEE, 2017, 37(11): 3216-3222, 3377.
9	李尚华, 李洪生, 韩玲. 350MW超临界空冷机组高背压循环水供热方案简析[J]. 华电技术, 2015, 37(12): 45-46, 75.
	LI Shanghua, LI Hongsheng, HAN Ling. Analysis of the high back pressure circulating water heating solution of 350MW supercritical air cooling unit[J]. Huadian Technology, 2015, 37(12): 45-46, 75.
10	成渫畏, 王学栋, 郝玉振. 140MW凝汽机组“双背压双转子互换”供热改造技术分析[J]. 发电与空调, 2013, 34(3): 5-8, 12.
	CHENG Xiewei, WANG Xuedong, HAO Yuzhen. Heating transformation technical analysis of double backpressure dual rotor swap for 140MW condensing unit[J]. Power Generation & Air Conditioning, 2013, 34(3): 5-8, 12.
11	闫森, 王伟芳, 蒋浦宁. 300MW汽轮机供热改造双低压转子互换技术应用[J]. 热力透平, 2015, 44(1): 10-12.
	YAN Sen, WANG Weifang, JIANG Puning. Application of double LP rotor interchangeable technology for heating improving in 300MW steam turbines[J]. Thermal Turbine, 2015, 44(1): 10-12.
12	万燕, 孙诗梦, 戈志华, 等. 大型热电联产机组高背压供热改造全工况热经济分析[J]. 电力建设, 2016(4): 131-137.
	WAN Yan, SUN Shimeng, GE Zhihua, et al. Thermo-economic analysis of high back pressure heating retrofit for large-scale cogeneration unit under full condition[J]. Electric Power Construction, 2016(4): 131-137.
13	万逵芳. 末级最小安全流量对空冷机组高背压供热的影响[J]. 汽轮机技术, 2017, 59(5): 381-384.
	WAN Kuifang. Influence of the stage’s minimum safe flow on heat supply of air cooling steam turbine unit[J].Turbine Technology, 2017, 59(5): 381-384.
14	戈志华, 胡学伟, 杨志平. 能量梯级利用在热电联产中的应用[J]. 华北电力大学学报(自然科学版), 2010, 37(1): 66-68.
	GE Zhihua, HU Xuewei, YANG Zhiping. The application of energy step utilize in co-generation[J]. Journal of North China Electric Power University, 2010, 37(1): 66-68.
15	时斌, 王宁玲, 李晓恩, 等. 供水温度对高背压热电联产系统能耗水平的影响[J]. 化工进展, 2018, 37(1): 96-104.
	SHI Bin, WANG Ningling, LI Xiao’en, et al. Impacts of water supply temperature on energy consumption of high back pressure cogeneration system[J]. Chemical Industry and Engineering Progress, 2018, 37(1): 96-104.
16	徐大懋, 邓德兵, 王世勇, 等. 汽轮机的特征通流面积及弗留格尔公式改进[J]. 动力工程学报, 2010, 30(7): 473-477.
	XU Damao, DENG Debing, WANG Shiyong, et al. Application of characteristic flow area of steam turbines and improvement on Flugel formula[J]. Journal of Chinese Society of Power Engineering, 2010, 30(7): 473-477.
17	宋之平. 单耗分析的理论和实施[J]. 中国电机工程学报, 1992(4): 17-23.
	SONG Zhiping. Theory and implementation of unit consumption analysis[J]. Proceedings of the CSEE, 1992(4): 17-23.
18	周少祥, 宋之平, 胡三高, 等. 单耗分析理论与能源利用的效率问题[J]. 中国能源, 2008(2): 42-43, 26.
	ZHOU Shaoxiang, SONG Zhiping, HU Sangao, et al. Energy consumption analysis theory and efficiency of energy utilization[J]. China Energy, 2008(2): 42-43, 26.
19	武宇, 颜士鑫, 武华. 1000MW火电机组热力系统优化分析[J]. 能源与环境, 2014(1): 45-47.
	WU Yu, YAN Shixin, WU Hua. Optimization of thermal system of 1000MW thermal power unit[J]. Energy & Environment, 2014(1): 45-47.
20	李恩峰. 单耗分析理论在热电联产中的应用[D]. 北京: 华北电力大学, 2004.
	LI Enfeng. The application of specific consumption analysis theory in CHP[D]. Beijing: North China Electric Power University, 2004.
21	陈海平, 王忠平, 石志云, 等. 基于单耗理论分析回热系统热经济性[J]. 汽轮机技术, 2012(6): 448-450, 454.
	CHEN Haiping, WANG Zhongping, SHI Zhiyun, et al. Thermal economy of regenerative system based on unit consumption theory[J]. Turbine Technology, 2012(6): 448-450, 454.
22	李月亲. 兆瓦级槽式太阳能汽轮机通流部分的优化设计[D]. 武汉: 华中科技大学, 2014.
	LI Yueqin. Design and optimization of turbine flow path for megawatt level parabolic trough solar thermal power station[D]. Wuhan: Huazhong University of Science & Technology, 2014.
23	邓世敏, 迟全虎, 金红光. 汽轮机通流部分改造后机组的回热系统优化[J]. 动力工程, 2004(2): 195-198.
	DENG Shiming, CHI Quanhu, JIN Hongguang. Optimization of the heat regenerative system after the modification of the flow path of the steam turbine[J]. Power Engineering, 2004(2):195-198.

项目	数值	项目	数值
发电功率/kW	238928	再热蒸汽流量/kg·h^-1	745105
主蒸汽压力/MPa	16.67	抽汽压力/MPa	0.791
再热蒸汽压力/MPa	3.191	抽汽量/kg·h^-1	190000
主蒸汽温度/℃	538	排汽压力/kPa	54
再热蒸汽温度/℃	538	排汽流量/kg·h^-1	444240
主蒸汽流量/kg·h^-1	970004	末级高加出口给水温度/℃	276.3

项目	数值	项目	数值
发电功率/kW	238928	再热蒸汽流量/kg·h^-1	745105
主蒸汽压力/MPa	16.67	抽汽压力/MPa	0.791
再热蒸汽压力/MPa	3.191	抽汽量/kg·h^-1	190000
主蒸汽温度/℃	538	排汽压力/kPa	54
再热蒸汽温度/℃	538	排汽流量/kg·h^-1	444240
主蒸汽流量/kg·h^-1	970004	末级高加出口给水温度/℃	276.3

工况	设计功率/kW	模拟功率/kW	相对误差/%
额定供热工况	238928	238900	0.01
最大供热工况	261781	261551	0.09
最小供热工况	196493	196236	0.13

工况	设计功率/kW	模拟功率/kW	相对误差/%
额定供热工况	238928	238900	0.01
最大供热工况	261781	261551	0.09
最小供热工况	196493	196236	0.13

项目	1^#高加	2^#高加	3^#高加	4^#除氧器	5^#低加	6^#低加	合计
?损/kW	990.062	1277.862	1348.868	3768.21	1267.125	129.27	8781.397
附加单耗/g·kW^-1·h^-1	0.4572	0.5901	0.6628	1.74	0.5851	0.0587	4.0939