Specification about flexible operation for steam turbine is now put forward by the new power plant client and discussed by regular users more frequently in China. This calls for more accurate design works than past to evaluate the influence to life time of the steam turbine components. As widely known, the transient temperature field analysis is most important boundary to life prediction. It is especially a challenge for complex structure component. Experimental investigation is a necessary and good measure for this task.
In this paper, an experimental investigation on heat up and cool down procedure of a steam turbine inlet valve casing is presented. The valve body with more than 70 temperature sensors is heat-up to 470°C, and then been cool-down to room temperature. The heat transfer behavior is investigated. The results are used to explain the thermal behavior during startup and the closing down of the steam turbine.