Online determination of the heat transfer coefficient at the inner surface of a cylindrical component in a thermal stress monitoring system for critical boiler pressure components - research data

Two approaches are described for evaluating the local heat transfer coefficient (HTC) on the inner surface of a transient cylindrical element. In the first approach, the HTC is obtained from measurements of the fluid and wall temperatures at a single location close to the inner surface. Here, the transient temperature distribution in the wall is assumed to depend solely on the radial coordinate. The second approach relies on recording the fluid and wall temperatures at six positions near the inner surface of the pressure element. This allows determination of the HTC even when the transient temperature field within the element is three-dimensional.