Development Of An On-line Monitoring System For Life Consumption Of Steam/Water Separator Of Ultra-supercritical Boiler

As the number of ultra supercritical boiler is constantly increasing, and on the basis of maintaining the plant power supply, the online monitoring and management for the life consumption of the expensive pressure components of boiler is an effective way to reduce power production costs and ensure the safety in production.The life loss of the high temperature pressure components is caused by the two main factors that are life low cycle fatigue and creep loss. In this paper, we made introduction and analysis of stress calculation methods, and identify the most dangerous point as the object of research and calculation, as long as the safe operation of the part are ensured, the entire component will be safe. This article discussed the theory and calculation method of stress concentration. The rain-flow method is used to count the fatigue cycle. On this basis, according to fatigue damage calculation, this paper chose international general method and also approved by the public common American that is ASME fatigue life calculation method. The Larson-Miller method was used to creep life loss calculation. The calculation method is not only applicable to steam/water separator, but suitable for the life calculation such as superheater and reheater high temperature press part after on the analysis of the operation environment and mechanical components.Through the selected effective calculation method of the stress, rain flow method, the low cycle fatigue damage and creep fatigue damage, combining the simplified calculation method that is suitable for online monitoring and the structure characteristics of the stream/water separator, the On-line Monitoring System for Life Consumption of Steam/water Separator based on the SIS system used in1000MW ultra supercritical boiler stream/water separator was developed. the on-line monitoring system of the loss of life, the On-line Monitoring System for Life Consumption of Steam/water Separator was constituted of the main data acquisition system, power plant SIS system and computer server running calculation system, and the auxiliary parts that poss display and print function, through selection of the real-time monitoring data and complete calculation and preservation in the service of a computing system operation, it does not affect the power plant operating system, so ensure the safety. To ensure that the calculation results are safe and accuracy, this paper according to the data of operation calculated the life loss, and has gotten reasonable calculation results.The system has been through the acceptance of the power plant working committee, and has been installed in the unit.