LIFE-PROLONGATION METHOD OF HIGH-TEMPERATURE PIPING, LIFE-PROLONGATION STRUCTURE OF HIGH-TEMPERATURE PIPING, AND METAL TEMPERATURE CONTROL METHOD OF HIGH-TEMPERATURE PIPING

摘要

PROBLEM TO BE SOLVED: To provide a life-prolongation method of a high-temperature member and a life-prolongation structure of a high-temperature member capable of prolonging the remaining life of a high-temperature member without lowering a total operation temperature of a plant and without lowering operation efficiency of the plant, and a control method of a metal temperature of high-temperature piping.SOLUTION: When a portion having a high risk of creep rupture (a weld zone having a high creep damage degree) is found through life evaluation of creep rupture in a weld zone 12 of a high-temperature piping 11, which is a high-temperature member, and it is determined that regular continuous use is not allowable, part of a thermal insulation material 13 covering the portion having high risk of creep rupture in a rotation direction is removed to make it an exposed portion 14, to locally decrease the outer surface temperature of the piping 11, and to prolong the life of the portion having high risk of creep rupture.