Failure analysis on unexpected wall thinning of heat-exchange tubes in ammonia evaporators

摘要

A failure incident of heat-exchange tubes in ammonia evaporators, which suffered from Received 7 October 2014 unexpected wall thinning after only one-year service with respect to their original design Received in revised form 13 January 2015 Accepted 13 January 2015 Available online 28 January 2015 lifetime of fifteen years, was reported and carefully analyzed. After overall inspection, many tube walls in the evaporators were found to experience severe degradations at both sides with distinct corroded defects and general cracking of corrosion layers. Thus, comprehensive investigations including external appearance, microscopic morphology and chemical.