Studying the causes of destruction of steam superheater tubes in boiler equipment

L. Opryshko, T. Golovnyak
{"title":"Studying the causes of destruction of steam superheater tubes in boiler equipment","authors":"L. Opryshko, T. Golovnyak","doi":"10.15407/mom2021.04.052","DOIUrl":null,"url":null,"abstract":"Results of comprehensive studies of samples of prematurely destroyed 57×4 mm steam superheaer tubes of STBA 22 steel used in a boiler unit of Singburi Sugar Co, Ltd factory (Thailand) are presented. The tubes were manufactured at Interpipe Niko Tube Ltd. (Ukraine) according to JIS G 3462 Standard (Japan). They were destroyed in a short (~240 hrs) term of operation. The cause of premature destruction of tubes of the above steel grade and size assortment in the boiler unit has been established. Based on present-day investigation methods (metallography, X-ray diffraction, etc.), it was found that the tubes were operated with violation of fuel combustion conditions and heat-carrying agent circulation. Characteristic features of operation of damaged tubes include high thermal stresses from the side of the fire-chamber and limitation (or absence) of circulation of the heat-carrying agent (blockage in bends, drum heads, etc.). During operation, the tubes were also exposed to significant thermal vibration stresses (unstable combustion conditions). Prolonged overheating occurred at temperatures above 1000 °C because of violation of circulation of heat-carrying agent and unstable combustion mode. High thermal stresses at almost complete absence of a heat-carrying agent, uneven distribution of growing heat flows caused by violation of the combustion mode in the fire-chamber contributed to accelerated degradation of structure and thermal destruction of the tube metal. In a short term of operation (~240 hours), there was a significant change in the tube size (accelerated high-temperature creep) and complete recrystallization of metal structure throughout the entire wall thickness of the damaged tubes. It has been established that the accelerated degradation of metal microstructure in the destroyed tubes was associated with both overheating of the tube wall and the as-delivered metal structure non-recommended for operation at high temperatures and pressures. It was shown that it is necessary to adjust the heat treatment conditions for these tubes at Interpipe Niko Tube Ltd. The study results have made it possible to develop recommendations for eliminating violations of operating conditions and establishing control of actual heat flows in the most thermally loaded sections of the Singburi Sugar Co. Ltd factory’s steam boiler superheater. Taking into account peculiarities of the boiler equipment and its operating conditions, it was also recommended to use a more heat-resistant and refractory steel instead of the currently used material for manufacture of the steam superheater tubes. Keywords: boiler tube, steam superheater, damage, thermal destruction, structure degradation, combustion conditions, heat carrier circulation, overheating.","PeriodicalId":33600,"journal":{"name":"Metaloznavstvo ta obrobka metaliv","volume":" ","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2021-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Metaloznavstvo ta obrobka metaliv","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.15407/mom2021.04.052","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0

Abstract

Results of comprehensive studies of samples of prematurely destroyed 57×4 mm steam superheaer tubes of STBA 22 steel used in a boiler unit of Singburi Sugar Co, Ltd factory (Thailand) are presented. The tubes were manufactured at Interpipe Niko Tube Ltd. (Ukraine) according to JIS G 3462 Standard (Japan). They were destroyed in a short (~240 hrs) term of operation. The cause of premature destruction of tubes of the above steel grade and size assortment in the boiler unit has been established. Based on present-day investigation methods (metallography, X-ray diffraction, etc.), it was found that the tubes were operated with violation of fuel combustion conditions and heat-carrying agent circulation. Characteristic features of operation of damaged tubes include high thermal stresses from the side of the fire-chamber and limitation (or absence) of circulation of the heat-carrying agent (blockage in bends, drum heads, etc.). During operation, the tubes were also exposed to significant thermal vibration stresses (unstable combustion conditions). Prolonged overheating occurred at temperatures above 1000 °C because of violation of circulation of heat-carrying agent and unstable combustion mode. High thermal stresses at almost complete absence of a heat-carrying agent, uneven distribution of growing heat flows caused by violation of the combustion mode in the fire-chamber contributed to accelerated degradation of structure and thermal destruction of the tube metal. In a short term of operation (~240 hours), there was a significant change in the tube size (accelerated high-temperature creep) and complete recrystallization of metal structure throughout the entire wall thickness of the damaged tubes. It has been established that the accelerated degradation of metal microstructure in the destroyed tubes was associated with both overheating of the tube wall and the as-delivered metal structure non-recommended for operation at high temperatures and pressures. It was shown that it is necessary to adjust the heat treatment conditions for these tubes at Interpipe Niko Tube Ltd. The study results have made it possible to develop recommendations for eliminating violations of operating conditions and establishing control of actual heat flows in the most thermally loaded sections of the Singburi Sugar Co. Ltd factory’s steam boiler superheater. Taking into account peculiarities of the boiler equipment and its operating conditions, it was also recommended to use a more heat-resistant and refractory steel instead of the currently used material for manufacture of the steam superheater tubes. Keywords: boiler tube, steam superheater, damage, thermal destruction, structure degradation, combustion conditions, heat carrier circulation, overheating.
查看原文
分享 分享
微信好友 朋友圈 QQ好友 复制链接
本刊更多论文
锅炉设备蒸汽过热器管损坏原因的研究
本文介绍了泰国Singburi糖业有限公司锅炉机组中stba22钢的57×4 mm蒸汽过热管过早损坏样品的综合研究结果。这些管子由Interpipe Niko Tube Ltd.(乌克兰)根据JIS G 3462标准(日本)制造。它们在短时间内(约240小时)被摧毁。找出了锅炉机组中上述钢种和尺寸组合管过早损坏的原因。根据现有的研究方法(金相、x射线衍射等),发现这些管道的运行违反了燃料燃烧条件和载热剂循环。损坏管道的运行特征包括来自火室侧面的高热应力和热传导剂循环的限制(或缺乏)(弯道,鼓头等堵塞)。在运行过程中,这些管道还暴露在显著的热振动应力(不稳定的燃烧条件)下。在温度超过1000℃时,由于载热剂的循环被破坏,燃烧方式不稳定,导致长时间过热。在几乎完全没有载热剂的情况下产生的高热应力,以及在火室中违反燃烧模式导致的不断增长的热流分布不均匀,都有助于加速结构的退化和管金属的热破坏。在短时间内(~240小时),管的尺寸发生了明显的变化(高温蠕变加速),损坏管的整个壁厚的金属结构完全再结晶。研究表明,破坏后的钢管中金属微观结构的加速退化与管壁过热和交付时的金属结构不适合高温高压运行有关。结果表明,有必要对这些钢管的热处理条件进行调整。研究结果使我们有可能提出建议,以消除违反操作条件的情况,并在Singburi糖业有限公司工厂蒸汽锅炉过热器的最热负荷部分建立实际热流控制。考虑到锅炉设备的特点及其运行条件,建议使用耐热性和耐火性能更好的钢代替目前使用的蒸汽过热器管制造材料。关键词:锅炉管,蒸汽过热器,损坏,热破坏,结构退化,燃烧条件,热载体循环,过热。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
求助全文
约1分钟内获得全文 去求助
来源期刊
自引率
0.00%
发文量
15
审稿时长
8 weeks
期刊最新文献
Environmental aspects of foundry aluminum slag processing Complex modification of AlSi9Cu3(Fe) alloy by using cobalt, vanadium and molybdenum Trends in the global market of iron and iron castings in the first quarter of the 21st century Determination of the dispersion hardening ability of a new die steel with controlled austenitic transformation Prediction of the mechanical properties of gray cast iron (probabilistic approach)
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
0
微信
客服QQ
Book学术公众号 扫码关注我们
反馈
×
意见反馈
请填写您的意见或建议
请填写您的手机或邮箱
已复制链接
已复制链接
快去分享给好友吧!
我知道了
×
扫码分享
扫码分享
Book学术官方微信
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术
文献互助 智能选刊 最新文献 互助须知 联系我们:info@booksci.cn
Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。
Copyright © 2023 Book学术 All rights reserved.
ghs 京公网安备 11010802042870号 京ICP备2023020795号-1