Monitoring of thermal stresses in pressure components of large steam boilers

Abstract

In order to rise the efficiency of electric energy production in steam power stations, the parameters of fresh steam are higher, achieving in supercritical power blocks pressure of the order of 30 MPa and temperatures around 600 °C. On the other hand it increases the wall thickness of the pressure component, despite introducing new steel grades. Because the thick-walled boiler components are subjected to the irregular and fast temperature changes, it is necessary to monitor the operation of the thick-walled pressure components, especially during boiler start-up and shut-down. A new system for monitoring the temperature changes, thermal stresses and rate of heating allows to determine a lot of parameters. All the measured and calculated data are available in the on-line mode and are displayed on the monitor.