Sensitivity Analysis About Transient Three-Dimensional IHCP With Multi-Parameters in an Elbow Pipe With Thermal Stratification

Pipelines with thermal stratification are common in nuclear power plants, and the thermal stratification may induce thermal fatigue and lead to leakage, so thermal stratification analysis of the pipeline is particularly significant. Due to the requirement of structural integrity, for the piping system of nuclear power plants, it is not allowed to trepan for installing sensors to measure the internal parameters. The inverse heat conduction problem (IHCP) based on the easily available temperature information of the outer wall can precisely estimate the boundary conditions of the inner wall. However, the precision of inverse estimation is influenced by the measuring precision, the number and the arrangement of measuring points. This work aims at the sensitive analysis about the measuring errors and the number and locations of measuring points. The research is based on an elbow pipe with thermal stratification-a pipe type commonly used in industry. Because it is easy to disturb the flow field to install sensors inside the pipeline, and it is difficult to calculate the convective heat transfer coefficient, the numerical experiments are taken in this study. The results showed that the IHCP with multi-parameters had certain anti-noise property and the number and locations of the measuring points had a certain influence on the calculation accuracy.