1000 MW超超临界二次再热锅炉吹管方案比较与优化  

Comparison and Optimization of Pipe Blowing Schemes for 1000 MW Ultra Supercritical Secondary Reheat Boiler

作　　者：杨博[1] 王林[1] 刘辉[1] 牛佩[1] 高景辉[1] YANG Bo;WANG Lin;LIU Hui;NIU Pei;GAO Jinghui(Xi'an Thermal Power Research Institute Co.Ltd.,Xi'an 710054,China)

机构地区：[1]西安热工研究院有限公司,陕西西安710054

出　　处：《工业加热》2023年第7期13-17,共5页Industrial Heating

基　　金：国家重点研发计划项目(2020YFF0218104)。

摘　　要：为提高1000 MW超超临界二次再热锅炉蒸汽吹管系数,改善管道吹扫质量,对某电厂3号锅炉吹管系数偏低原因进行了分析,认为临吹门前的管路阻力过大导致了过热器吹管系数偏低,指出了超高压主汽门、临吹门、支管弯头等三处阻力增大点,并利用了临吹门与主蒸汽管通流面积比来评估临吹门的通畅性。基于3号锅炉的研究结论,对4号锅炉临吹系统进行了针对性的阻力优化,采用临时管将超高压主汽门旁路,同时临吹门改用双阀-支管布置方式。采用上述改进措施后,在过热器单吹阶段,4号锅炉较3号锅炉最大吹管压降比值提高21.6%,过热器出口蒸汽压力则降低23.1%;在过热器与再热器串联吹扫阶段,4号锅炉过热器、一次再热器、二次再热器最大吹管压降比值,较3号锅炉分别提高45.8%、68.7%、64.1%,过热器出口蒸汽压力则由9.3 MPa降低至8.5 MPa,吹管全程过热器压降比值稳定维持在1.40以上,蒸汽吹扫质量与临时吹管系统的安全性均得到可靠保障,相关经验可供后续同类机组参考。In order to improve the steam blowpipe coefficient of 1000MW ultra⁃supercritical secondary reheat boiler and improve the pipeline purge quality,the reasons for the low blowpipe coefficient of No.3 boiler in a power plant were analyzed.It was believed that the pipeline re⁃sistance in front of the blowpipe door was too large,resulting in the low blowpipe coefficient of the superheater.The flow area ratio between the front blowing door and the main steam pipe is used to evaluate the patency of the front blowing door.Based on the research conclusion of No.3 boiler,the resistance optimization of No.4 boiler blow⁃off system is carried out.Temporary pipe is used to bypass the main valve of ultra⁃high pressure,and double⁃valve⁃branch pipe arrangement is used for blow⁃off door.After adopting the above improvement measures,the maxi⁃mum blowpipe pressure drop ratio of No.4 boiler is 21.6%higher than that of No.3 boiler,and the steam pressure at the outlet of superheat⁃er is 23.1%lower.In the series purging stage of superheater and reheater,the maximum pressure drop ratio of the superheater,primary re⁃heater and secondary reheater of boiler No.4 increased by 45.8%,68.7%and 64.1%,respectively,compared with that of boiler No.3.The steam pressure at the outlet of the superheater decreased from 9.3 MPa to 8.5 MPa,and the pressure drop ratio of the superheater during the whole process of the blow pipe remained stable above 1.40.The quality of steam purging and the safety of temporary blowpipe system have been reliably guaranteed,and relevant experience can be used as reference for similar units in the future.

关 键 词：1000 MW 二次再热 压降比 临吹门 阻力优化 

分 类 号：TM621.2[电气工程—电力系统及自动化]