Formulation of Corrosion Products in Low Temperature Feedwater Drain of Power Plant

doi:10.11930/j.issn.1004-9649.201802019

Abstract

Abstract: Originated from carbon steels in feedwater drain due to flow accelerated corrosion, the corrosion products may be transported everywhere throughout the entire steam-water system, which can seriously impact the operation security and lifespan of thermal unit. The generation model of corrosion product in feedwater drain is built based on the mass balance. Then the effect of three main factors on generation process is analyzed, i.e., porosity of oxide layer, diffusivity of iron in the fluid and fluid pH value. The result data shows the corrosion rate is proportional to the former two items, but inversely proportional to the fluid pH. The porosity of oxide layer can be reduced significantly by virtue of oxygenated treatment. However, the more complicated of pipeline arrangement and the rougher of the pipeline surface, the greater of diffusivity will be reached in the fluid. In actual operation of power plant, the formulation of corrosion products can be effectively reduced by restraining the flow accelerated corrosion in combination with the optimization of pipeline structure and water treatment under the condition of optimum pH and dissolved oxygen.

Key words: coal-fired power plant, flow accelerated corrosion, steam-water cycle, corrosion products, generation model, mass balance

CLC Number:

JIANG Dongfang, ZHANG Mian, KHAN Izhar Hsan, WANG Chao, ZHU Zhongliang, ZHANG Naiqiang, XU Hong. Formulation of Corrosion Products in Low Temperature Feedwater Drain of Power Plant[J]. Electric Power, 2018, 51(5): 118-122,133.

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URL: https://www.electricpower.com.cn/EN/10.11930/j.issn.1004-9649.201802019

https://www.electricpower.com.cn/EN/Y2018/V51/I5/118

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