Study on High-Cycle Thermal Fatigue Evaluation for Thermal Striping in Mixing Tees with Hot and Cold Water (2) : Design Chart (2); Unsteady Heat Transfer Characteristics and Heat Transfer Coefficient

Abstract

Thermal Striping tests in mixing tees with hot and cold water were conducted for three types of flow conjunctions in order to establish an evaluation method for high-cycle thermal fatigue of piping systems. The main teets weer temperature fluctuation measurement tests carried out using metal pipes to evaluate the unsteady heat transfer coefficient based on measured temperature fluctuations of fluid and pipe wall. From the above data, heat transfer coefficients Fp of types A and B are approximately 0.9-3.0 times compared with steady heat transfer coefficient. That of type C is approximately 5.0 times.