Leakage Analysis of Heat Exchange Tubes of Quench Oil-Dilution Steam Generator
After eight years of operation,nine quench oil-dilution steam generators in the quench unit of an ethylene cracking unit experienced frequent leakage of the heat exchange tubes.A series of analytical techniques were employed,including macroscopic examination,internal and external diameter measurement,chemical composition analysis,metallographic structure analysis,hardness testing,and scanning electron microscopy analysis of corrosion morphology.Energy-dispersive X-ray spectroscopy and X-ray diffraction analysis were employed to examine the physical and chemical characteristics of the heat exchange tube exhibiting the most severe leakage.The results of the physical and chemical analysis indicated that the primary corrosion mechanism was the frequent fluctuations in pH levels of the process water.The vaporization-erosion corrosion process accelerated the corrosion failure of the heat exchange tubes,while the oxygen concentration corrosion had a notable promoting effect on the corrosion of the heat exchange tubes.This ultimately led to a perforation in the heat exchange tubes.
万方数据
维普
