摘要
某330 MW机组低温省煤器在运行中出现水位降低的情况,检修发现换热管束有沙眼状漏点及磨穿孔洞。根据现场烟道壁冲刷、积灰及膨胀节磨损状况,通过CFD对主烟道、低温省煤器入口腔体、管束区域的流体进行了模拟分析。结果表明:不规则的主烟道结构使原膨胀节处流动复杂,膨胀节的钢板受到主气流的强力冲刷,局部速度高达36 m/s,超出烟道壁面的加强结构约有34%区域处于高速气流区;原烟道的优化可使上游烟气的流速分布更接近烟道流体平均值:导流板数量和宽度的合理取值可使低温省煤器实际运行参数与设计值接近,且能避免导流板尾部气流对前排管束的冲刷。入口腔体内或管束段设计防磨管,可减少烟气对换热管的直接冲刷及更换成本。
The water level could not be maintained during the operation of the low temperature economizer of a 330MW power plant.It was found that there were trachoma leakage points and wear holes in the bundle.According to the wall conditions,ash accumulation and destroyed expansion joint,Analysis about main flue、the inlet construction of low temperature economizer and the heat exchange tube area was made by CFD.The simulation results show that the irregular main flue structure makes the flow characteristic of the original expansion joint complicated.The steel plate of the expansion joint is strongly scoured by the main airflow,and the local velocity is as high as 36m/s.About 34%of the area beyond the reinforced structure of the flue wall is in the high-speed airflow area;The optimization of the main flue can make the flow velocity distribution of upstream flue gas more close to the mean value of velocity;The reasonable value of the number and width of the deflector can make the actual operating parameters close to the design value,and can avoid the scour to the front tube bundle.The design of anti-wear tube into the inlet or tube bundle section can reduce the direct erosion of flue gas on the heat exchange tube and the cost of replacement.
作者
张海茹
吴昊
ZHANG Hairu;WU Hao(Jiangsu Wisdom Engineering&Technology Co.,Ltd,Nanjing 210009,China;School of Energy and Mechanical Engineering,Nanjing Normal University,Nanjing 210042,China)
出处
《环境工程》
CAS
CSCD
北大核心
2023年第S02期824-827,共4页
Environmental Engineering
基金
国家自然科学基金(51806107)
关键词
低温省煤器
数值模拟
膨胀节
真实管束
low temperature economizer(LTE)
numerical analysis
expansion joint
real tube
