Study on High-Cycle Thermal Fatigue Evaluation for Thermal Striping in Mixing Tees with Hot and Cold Water (3) : Design Chart (4); Frequency Characteristics of Temperature Fluctuation by Rain Flow Method

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 tests were temperature fluctuation measurement tests carried out using metal pipes to evaluate frequency characteristics of temperature fluctuation. By FFT analysis, dominant frequency of temperature fluctuation was not observed. Design charts for evaluation stress fatigue have been prepared by using the rain flow method.