汽轮机排汽湿度的在线监测方法及工业试验研究

蒸汽湿度对汽轮机的安全性和经济性有重要的影响.该文提出了可以在线监测汽轮机排汽湿度的双区加热方法,将加热段分为蒸发段和过热段,各段独立加热,通过过热段测量蒸汽流量,简化了测量装置,提高了探针的可靠性.湿度测量探针设计中仔细考虑了散热损失、汽化长度、热阻力的影响,提高了测量精度,实现了对汽轮机排汽湿度的长期在线监测.对采用双区加热法研制的湿度测量探针进行了工业试验,试验结果表明测量结果是可信的.

STUDY ON A METHOD OF WETNESS MEASUREMENT ON LINE AND INDUSTRIAL TEST FOR STEAM TURBINE EXHAUST

Steam wetness has great influence on safety and efficency for steam turbine. A method of on line monitoring wetness fraction based on double region heating for steam turbine exhaust is presented in this paper. The heating tube is divided into evaporation region and superheated region, which is heated individually. The steam flow rate is measured in superheated region, so that the measuring system is simplified and the reliability of wetness probe is enhanced. The heat loss, evaporation tube length and thermal drag is studied on the design of wetness probe, thus the measurement accurency is improved and the the monitoring wetness fraction of steam turbine exhaust could be last for a long time. The wetness probe based on the method of double region heating is tested industrially and the results show it is credible.