排ガスエコノマイザ蒸発管の損傷解折

概要

論文の詳細を見る
The circumferential cracking of the exhaust gas economizer tubes with rectangular fins were experienced recently, and it was found that some of these had penetrated the tube wall. As a result of failure analysis, it was assumed that the crack initiations were caused by superposing the thermal stress upon the residual stress. The finite element analysis on unsteady state thermal stress, that is, two kinds of engine starting operation condition or the unsteady film boiling condition were made. Relatively high tensile stresses were calculated at the inner surface of the tube in a case of thermal conditions. Comparing these results to many other failures experienced, the cracks might be initiated by the alternating thermal stress caused by film boiling superposed upon the residual stress caused by welding.
財団法人日本海事協会の論文