화력발전소의 보일러 튜브 곡관 형상이 수명감소에 미치는 영향

In this study, the numerical simulation has been performed for real power plant boiler tube bends specimen to determine the influence of shape and analysis result was compared with metallurgical investigation results for rupture damaged one. Using the common program, the change of first principle stress level and distribution in tube bend was compared. Analysis result showed the 300% stress increase in bend extrados external surface of the high heat flux zone and distribution pattern change. The cause of change was dominated by ovality. The calculated creep lifetime of high ovality bend was dropped below 3% of normal straight tube life time. And the metallurgical investigation result for rupture damaged tube bend from power plant manifest the relationship between stress change and rupture pattern. According this study, the effect of tube bend shape imperfection was understood.