nline Diagnostics of Steam Pipes and Thick-Walled Boiler Components - A Comparison of Methods Based on Operational Experience

摘要

Operation and monitoring of pressure parts in power plants are subject to particular require- ments: high availability, low maintenance costs, operational safety. The updated German Ordinance on Industrial Safety and Health (BetrSichV) according to the European law gives plant operators more flexibility but also more responsibility. Due to the rapid increase in the use of renewable energies, there is a requirement for managing plant operations with significantly faster load changes and more frequent start-up and shutdown procedures of thermal power plants. For the operators, this situation represents both a chance and a challenge. It is the prerequisite for a reliable power generation. In the past, maintenance frequency was defined on the basis of experience and with high safety margins (time-based maintenance). The condition-based maintenance means a significant improvement in terms of economic efficiency. Continuous diagnosis allows the condition of the components to be monitored. Using this method it will be possible to state whether the actual (alternating) operation mode in relation to the given operation conditions will lead to an increase or decrease of the service life and when special inspections or a replacement of the components are required. In addition, an automatic projection (extrapolation into the future) of the lifetime consumption becomes possible. For this, the previous stress of the components and future requirements (e.g. load regime) to power plant operation are considered in order to optimize the plant operation. The talk will be based on the operational experience using online diagnosis systems to determine the condition of thick-walled boiler components and will give a comparison of actual methods. Part 1 [7] of this paper which was published in the context of PowerGen Europe 2011 in Milan focuses on the stress monitoring of steam pipes. Part 2 (PowerGen Europe 2013, Vienna) concentrates on the lifetime monitoring of thick-walled boiler components.