Monitoring and Analyzing of Wall Temperature Fluctuations for Thermal Fatigue in Elbow Pipe

摘要

Turbulent penetration and unsteady thermal stratification can occur when hot/cold fluids mix and valve leakage in some elbow pipe regions in the nuclear power plant. Temperature fluctuations with large amplitude and high frequency caused by the unstable thermal stratification can lead to time-varying thermal stress and even induce thermal fatigue. Monitoring of wall temperature fluctuations of elbow pipes has received considerable interest because the thermal fatigue failure of these pipes could present severe environmental implications and large economic losses. In this study, based on the energy conservation law and the turbulent permeation laws, the linear interpolation method is used in this paper to calculate temperature distributions in the fatigue-sensitive region. The FLUENT software is used to verify algorithm effectiveness and accuracy, which provides a new solution for indirect measurement of internal temperature of the elbow pipe.