Measuring Method of Inner Wall Temperature Fluctuations for Thermal Fatigue in T-junction Pipe

The T-junction configuration is a classical test case for thermal fatigue phenomena. Turbulent penetration and unsteady thermal stratification can occur when hot and cold fluids mix in T-junction pipes at NPPs, which may lead to time-varying thermal stress and even induce thermal fatigue failure. In this paper, mock-up experimental and analyses were conducted to develop a new method to calculate the wall temperature fluctuations of mixing T-junction pipes only by the temperature and velocity information of the fluid in branch and main pipe. The experimental results prove the effectiveness of this new method.