真空法启动降低锅炉蒸汽侧金属表面氧化膜温差试验研究

doi:10.11930/j.issn.1004-9649.201609039

摘要/Abstract

摘要： 单元机组一般采用压力法冷态启动。超临界机组锅炉采用压力法冷态启动，必然出现对流受热面干烧升温再通蒸汽冷却现象，氧化膜会承受100℃左右的冷却温差产生的热应力，而较大热应力可能导致氧化膜剥落。采用真空法启动，锅炉点火前受热面内即流通低温饱和蒸汽，可有效降低启动过程中过热器管表面氧化膜的温差。在湖南华电长沙发电有限公司2号机组锅炉上进行了真空法启动试验，取得了较好的效果，锅炉点火前后受热面温差明显减小，有效减少了氧化膜脱落风险。该方法无需设备改造，操作简单可靠。

关键词: 超临界机组, 锅炉, 真空法启动, 氧化膜, 热应力, 过热器管

Abstract: Generally, the generation unit is started from cold state by means of pressure method. However, when this method is applied in supercritical boiler, it is inevitable that convective heating surface will be heated dry without steam and, then cooled down with steam. As a result the oxide scales will have to withstand the thermal stress from about 100℃ cooling temperature difference, which can cause the oxide scales flaking. In this paper, the vacuum method is adopted to start the unit. The low temperature saturated steam flows the heated surface of the boiler before ignition, which can effectively avoid the peeling off of the oxide scales during the startup process. corresponding experimental study is carried out in No. 2 boiler in Changsha Power Station Co., Ltd of Hunan CHD and satisfactory results are obtained. The temperature difference of the heating surface is significantly reduced before and after the ignition of the boiler, which effectively diminishes the risk of oxide scales flaking. The method is simple and reliable with no equipment modification needed.

Key words: supercritical unit, boiler, vacuum method, oxide scales, thermal stress, superheater tube

中图分类号:

TK227.7

何文波. 真空法启动降低锅炉蒸汽侧金属表面氧化膜温差试验研究[J]. 中国电力, 2018, 51(3): 7-12.

HE Wenbo. Experimental Study on Reducing Thermal Stress of Steam-Side Oxide Scales by Vacuum Method[J]. Electric Power, 2018, 51(3): 7-12.

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https://www.electricpower.com.cn/CN/Y2018/V51/I3/7

参考文献

[1] 贾建民, 陈吉刚, 李志刚, 等. 18-8系列粗晶不锈钢锅炉管内壁氧化皮大面积剥落防治对策[J]. 中国电力, 2008, (05): 37-41. JIA Jianmin, CHEN Jigang, LI Zhigang, et al. Countermeasures against massive exfoliation of oxidation scale on the internal surface of coarse grained 18-8 type stainless steel boiler tubes[J]. Electric Power, 2008, 41(5): 37-41.
[2] 杨守伟. 超临界锅炉氧化膜的形成机理及防范措施[J]. 河北电力技术, 2010, 29(1): 44-46. YANG Shouwei. Formation mechanism and countermeasures of oxidation velamen of supercritical pressure boilers[J]. Hebei Electric Power, 2010, 29(1): 44-46.
[3] 杨德钧, 沈卓声.金属腐蚀学[M]. 2版. 北京: 冶金工业出版社, 1999: 27-29.
[4] 徐洪. 给水加氧处理引发蒸汽通道氧化皮剥落的机理[J]. 动力工程学报, 2011, 31(9): 672-677, 699. XU Hong. Mechanism of OT-induced exfoliation of duplex scale in steam path[J],.Journal of Chinese Society of Power Engineering, 2011, 31(9): 672-677+699.
[5] 曾令大, 张开利, 陈启卷, 等. 超临界锅炉蒸汽侧氧化皮生成原因与对策[J]. 中国电力, 2010, 43(12): 46-50. ZENG Lingda, ZHANG Kaili, CHEN Qijuan, et al. Formation mechanism and preventive measures for steam side oxide scale in superheater of supercritical boilers[J]. Electric Power, 2010, 43(12): 46-50.
[6] 谢国胜, 龙会国, 龙毅. 9Cr1MoVNb钢蒸汽侧氧化膜形态及其形成机理[J]. 中国电力, 2013, 46(1): 54-58. XIE Guosheng, LONG Huiguo, LONG Yi.Study on steam-side oxidation mechanism and characterization of oxide scales grown on T91 tubes[J]. Electric Power, 2013, 46(1): 54-58.
[7] 刘欣, 李明, 孙树翁, 等. 氧化皮生成与等离子体煤粉点火锅炉启动的关系[J]. 中国电力, 2014, 47(8): 98-102. LIU Xin, LI Ming, SUN Shuweng, et al. Correlation between oxide skin formation and plasma ignition boiler startup[J]. Electric Power, 2014, 47(8): 98-102.
[8] SCHÜTZE M. Mechanical properties of oxide scales[J]. Oxidation of Metals, 1995, 44(1/2): 29-61.
[9] SCHÜTZE M, TORTORELLI P F, WRIGHT I G. Development of a comprehensive oxide scale failure diagram[J]. Oxidation of Metals, 2010, 73(3/4): 389-418.
[10] 杨景标, 郑炯, 邱燕飞, 等. 过热器和再热器氧化皮开裂与剥落的预测与控制[J]. 锅炉技术, 2011, 42(5): 48-52. YANG Jingbiao, ZHENG Jong, QIU Yanfei, et al. Prediction and control of scale cracking and exfoliation on superheater and reheater tube steels[J]. Boiler Technology[J]. 2011, 42(5): 48-52.
[11] 王力园. 超临界锅炉高温受热面氧化皮剥落的原因及防治[J]. 电力安全技术, 2011, 13(5): 10-12. WANG Liyuan. Causes and prevention of scouring of high temperature heating surface of supercritical[J]. Electric Safety Technology, 2011, 13(05): 10-12(in Chinese).
[12] 边彩霞, 周克毅, 胥建群, 等. 锅炉过热器蒸汽侧氧化膜瞬态应力的有限元分析[J]. 动力工程, 2008, 28(5): 696-700. BIAN Caixia, ZHOU Keyi, XU Jianqun, et al. Finite element analysis on transient stresses of oxide scales at steam side of boiler superheater[J]. Journal of Power Engineering, 2008, (05): 696-700.
[13] SABAU A S, WRIGHT I G. On the estimation of thermal strains developed during oxide growth[J]. Journal of Applied Physics, 2009, 106(2): 023503-1-023503-8.
[14] WRIGHT I G, DOOLEY R B. Morphologies of oxide growth and exfoliation in superheater and reheater tubing of steam boiler[J]. Materials at High Temperature, 2014, 28(1): 40-57.
[15] WRIGHT I G, TORTORELLI P F.Program on technology innovation: Oxide growth and exfoliation on alloys exposed to steam[R]. Palo Alto, ERPI, 2007.
[16] SABAU A S, WRIGHT I G. Influence of oxide growth and metal creep on strain development in the steam-side oxide in boiler tubes[J]. Oxidation of Metals, 2010, 73(5/6): 467-492.
[17] WRIGHT I G, SABAU A S, DOOLEY R B. Development of strain in oxides grown in steam tubes[J]. Materials Science Forum, 2008, 595-598: 387-395.
[18] 王殿仲, 徐宪龙. 600 MW超临界锅炉高温受热面氧化皮形成与脱落原因分析及其改进措施[J]. 电力设备, 2008, 9(3): 45-47. WANG Dianzhong, XU Xianlong. Formation and falling-off cause analysis of iron scales on the high temperature heating surfaces of 600 MW supercritical boiler and improvement measures[J]. Electrical Equipment, 2008, 9(3): 45-47.
[19] 曹艳. 大型超(超)临界直流锅炉蒸汽加热启动技术研究[D]. 上海: 上海电力学院, 2014.
[20] 曹艳, 冯伟忠. 超(超)临界锅炉启动阶段出现的异常及防治[J]. 华东电力, 2013, 41(7): 1529-1532. CAO Yan, FENG Weizhong. Abnormal occurrence at the start-up phase of ultra-supercritical boiler and prevention measures[J]. East China Electric Power, 2013, 41(7): 1529-1532.