HIGH TEMPERATURE DESIGN AND DAMAGE EVALUATION OF MOD.9CR-1MO STEEL HEAT EXCHANGER

摘要

High temperature design and evaluation of creep-fatigue damage for sodium-sodium heat exchanger, DHX (Decay heat exchanger) in a sodium test loop have been conducted. The DHX is a shell- and tube-type heat exchanger with outer diameter of 21.7mm, thickness of 1.65mm and effective length of 1.73m. The DHX shell and tube materials were Mod.9Cr-1Mo steel. The temperatures of shell inlet and shell outlet in the DHX are 510°C and 308°C, respectively, while the temperatures of tube inlet and outlet are 254°C and 475°C, respectively. Three dimensional finite element analysis was conducted for the DHX and evaluation of creep-fatigue damage at several critical locations of the heat exchanger was carried out according to the elevated temperature design codes of the ASME Section III Subsection NH and RCC-MR. Evaluations on the integrity of the DHX and code comparisons were carried out for the critical locations of the DHX.