TCEC1442017过热器和再热器化学清洗导则16

ICS27.100F20备案号：53939-2016中国电力企业联合会标准T/CEC144—2017过热器和再热器化学清洗导则Guidelinesforchemicalcleaningofsuperheatersandreheaters2017-05-15发布2017-08-01实施中国电力企业联合会发布T/CEC144—2017I目次前言··································································································································································Ⅱ1范围······························································································································································12规范性引用文件··········································································································································13术语和定义··················································································································································14过热器和再热器化学清洗的确定···············································································································15清洗单位······················································································································································26技术要求······················································································································································27化学清洗工艺条件的确定···························································································································38化学清洗系统的设计和安装·······················································································································39化学清洗工艺过程······································································································································410清洗废液处理············································································································································511清洗质量指标············································································································································512清洗中的化学监督····································································································································613安全保证体系············································································································································6附录A（资料性附录）氧化皮的治理方法对比及化学清洗的意义·····························································7附录B（规范性附录）晶间腐蚀试验············································································································9附录C（资料性附录）腐蚀在线监测·········································································································10附录D（资料性附录）典型清洗系统图······································································································11附录E（规范性附录）除垢率测量方法·····································································································13T/CEC144—2017II前言本导则按照GB/T1.1—2009《标准化工作导则第1部分：标准的结构和编写》给出的规则起草。本导则由中国电力企业联合会提出。本导则由电力行业电厂化学标准化技术委员会归口。本导则主要起草单位：西安热工研究院有限公司、华能国际电力股份有限公司、神华国华（北京）电力研究院有限公司。本导则主要起草人：曹杰玉、李卫东、龙国军、姚建涛、张广文、刘锋、张贵泉。本标准在执行过程中的意见或建议反馈至中国电力企业联合会标准化管理中心（北京市白广路二条一号，100761）。T/CEC144—20171过热器和再热器化学清洗导则1范围本标准规定了过热器和再热器化学清洗的技术要求、质量指标和试验方法。本标准适用于运行炉和基建炉过热器、再热器的化学清洗。2规范性引用文件下列文件对于本文件的应用是必不可少的。凡是注日期的引用文件，仅注日期的版本适用于本文件。凡是不注日期的引用文件，其最新版本（包括所有的修改单）适用于本文件。GB8978污水综合排放标准GB/T4334金属和合金的腐蚀不锈钢晶间腐蚀试验方法DL/T523化学清洗缓蚀剂应用性能评价指标及试验方法DL/T794火力发电厂锅炉化学清洗导则3术语和定义下列术语和定义适用于本文件。3.1富铬层Cr-richlayer氧化皮合金元素偏聚，靠近基体位置的铬等元素含量高于基体合金的氧化层。富铬层具有降低氧化皮生长速度的作用。3.2气塞airlock立式管道内气体阻止液体流动的现象。4过热器和再热器化学清洗的确定4.1运行锅炉清洗条件4.1.1运行锅炉过热器和再热器的化学清洗，可以避免氧化皮脱落引起的爆管，减少汽轮机冲蚀，延长炉管寿命，参见附录A。4.1.2过热器和再热器符合下列条件之一的，应安排化学清洗：a）氧化皮脱落造成爆管事故，且发生氧化皮大面积脱落；b）氧化皮脱落造成下弯头管内沉积高度超过1/3管径。4.1.3过热器和再热器符合表1条件之一的，宜安排化学清洗。表1宜进行化学清洗的条件序号材质氧化皮厚度mm112Cr1MoV≥0.302T22、T23≥0.20T/CEC144—20172表1（续）序号材质氧化皮厚度mm3T91≥0.204TP347H、TP347HFG≥0.09注：采用金相显微镜法测量氧化皮总厚度。4.2基建锅炉清洗条件4.2.1再热器一般不进行化学清洗。出口压力为17.4MPa及以上机组的锅炉，再热器可根据情况进行化学清洗，但必须有消除立式管内的气塞和防止腐蚀产物在管内沉积的措施，并应进行应力腐蚀及晶间腐蚀试验，清洗液不应产生应力腐蚀及晶间腐蚀。4.2.2过热器垢量或腐蚀产物量大于100g/m2时，可选用化学清洗，但应有防止立式管产生气塞和腐蚀产物在管内沉积的措施，并应进行应力腐蚀及晶间腐蚀试验，清洗液不应产生应力腐蚀及晶间腐蚀。5清洗单位承担过热器和再热器化学清洗的单位应具备发电厂热力设备化学清洗单位A级能力，严禁无证清洗。6技术要求6.1清洗单位应具有防止发生堵管、气塞、晶间腐蚀的技术能力和相应的技术手段，并具有腐蚀在线监测装置。6.2制定清洗方案前，应进行相关试验，包括：——清洗配方试验。除垢率应达到质量标准要求，清洗过程中不应产生氧化皮大量脱落。——缓蚀剂性能评价试验。缓蚀剂性能应达到在清洗流速、温度、时间条件下的缓蚀效率。——晶间腐蚀评定试验。敏化后的奥氏体钢清洗后应无晶间腐蚀（见附录B）。6.3应具有腐蚀在线监测手段（参见附录C），并且在清洗过程中腐蚀速率发生异常时有相应的处理方法。6.4除正式系统壁温测点外，还应增加临时壁温测点，监测清洗过程中的堵管情况，测点数量应覆盖易发生堵管的管道。6.5清洗药品在清洗前应全部运抵现场，并检验合格。6.6清洗系统中应有防止异物进入正式系统的措施。6.7清洗结束后应对联箱、节流孔等处进行异物检查。6.8清洗回路中应设置流量监测装置，清洗开始前应用超声波流量计校正确认。6.9化学清洗开始前，清洗所需的分析仪器、试剂及药品准备完全。6.10清洗现场备有通信设备，以便与主控、化水等联系。6.11清洗现场及相关区域照明正常。6.12红外测温仪、超声波流量计及pH计等检测仪器具备使用条件。6.13清洗现场的劳保用品具备使用条件。6.14清洗现场的急救药品配备齐全。6.15参加化学清洗的人员由承包方负责安全技术交底，并完成对参加化学清洗的人员的安全培训。6.16化学清洗前应拆除或隔离易受清洗液损害的部件和其他配件。T/CEC144—201736.17清洗结束后应对热工仪表连接管，取样、排空、放水等管路进行放水冲洗。6.18化学清洗后设备内的有害残液、残渣应清除干净。6.19设备清洗后的质量应符合第11章的规定。6.20必须有完善的废液处理方案。清洗废液应就地处理、达标排放，排放时应符合GB8978的规定和当地环保标准。如果清洗废液必须外运，应交付给具有污水处理资质的企业，并提供相关证明材料。7化学清洗工艺条件的确定7.1化学清洗工艺条件的选择，应根据氧化皮成分，过热器或再热器布置形式、材质等，通过试验确定。清洗介质在保证清洗及缓蚀效果前提下，应综合考虑其经济性及环保要求等因素。7.2清洗范围的选择：氧化皮厚度达到清洗要求，并且易发生脱落堵管的管路均应参与清洗。清洗前应对被