Thermal Stress at the Junction of Skirt to Head in Hot Pressure Vessel

고온 수직형 압력용기 Skirt 부의 열응력에 관한 연구

  • 한명수 (대우중공업(주) 선박해양기술연구소) ;
  • 한종만 (대우중공업(주) 선박해양기술연구소) ;
  • 조용관 (대우중공업(주) 선박해양기술연구소)
  • Published : 1998.04.01

Abstract

It is well recognized that a excessive temperature gradient from the junction of head to skirt in axial direction in a hot pressure vessel can cause unpredicted high thermal stress at the junction and/or in axial direction of a skirt. this thermal stress resulting from axial thermal gradient may be a major cause of unsoundness of structural integrity. In case of cyclic operation of hot pressure vessels, the thermal stress becomes one of the primary design consideration because of the possibility of fracture as a result of cyclic thermal fatigue and progressively incremental plastic deformation. To perform thermal stress analysis of the junction and cylindrical skirt of a vessel, or, at least, to inspect quantitatively the magnitude and effect of thermal stress, the temperature profile of the vessel and skirt must be known. This paper demonstrated the temperature distribution and thermal stress analysis for the junction of skirt to head using F.E. analysis. Effect of air pocket in crotch space was quantitatively investigated to minimize the temperature gradient causing the thermal stress in axial direction. Effect of the skirt height on thermal stresses was also studied. Analysis results were compared with theoretical formulas to verify th applicability to the strength calculation in design field.

References

  1. Pressure Vessel Desing Handbook(2nd Ed.) Henry H. Bednar
  2. Fatigue Design(Life Expectancy of Machine Part) Eliahu Zahavi;Jesah. Kreiner
  3. ASME Paper No. 58-A-153 Desing and Analysis of Welded Pressure Vessel Skirt Supports N. A. Weil;J. J. Murphy
  4. Element of Heat Transfer M. Necati Ozisik;Yildiz Boyazitoglu
  5. AMSE Boiler & Pressure Vessel Code Sec.Ⅱ Part D. Properties ASME
  6. ABAQUS/Standard User's Manual(Version 5.6) HKS
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  8. ASME Boiler & Pressure Vessel Code Sec.Ⅷ Div. 2 ASME
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