Cooler Casing Fatigue Analysis: An ASME Approach

Abstract

Extended surface heat exchangers are widely adopted in centrifugal air compressors to transfer heat from compressed air to cooling water. These heat exchangers are enclosed in a casing which is made either by casting or fabrication. This paper reviews the cast casing fatigue qualification as per ASME Section VIII Division 2 guidelines. Casing is considered as a pressure vessel in industry which needs to be certified by ASME or PED or GB or CRN depending on the location of use. Machine operating parameters were used as inputs for fatigue screening criteria to determine whether the fatigue analysis is required as part of casing design. On failing the screening criteria, a detailed fatigue evaluation was performed. Coupled field analysis were ran in ANSYS and the maximum stress intensity values are used to compare against the material’s fatigue criteria on the pressure boundary and non-pressure boundary regions separately, to qualify the casing.