Research on Oxygenated Treatment for High Pressure Heater Drainage Water of Ultra Supercritical Units

doi:10.11930/j.issn.1004-9649.201902099

Abstract

Abstract: In order to avoid the potential risk of extensive oxidation skin peeling in the superheater and reheater that arises from dosing high concentration oxygen (a.k.a high oxygenated treatment), some power plants adopt the low concentration oxygenated treatment (a.k.a. low oxygenated treatment). However, this type of low oxygenated treatment of the feed water cannot solve the corrosion problem of the high-pressure heater drainage system. Therefore full protective oxygenated treatment of "feed water treatment with low concentration oxygen plus high pressure heater drainage treatment with individual dosing oxygen" is developed and applied to a 660 MW ultra-supercritical unit. The results show that with the implementation of this full protective oxygenated treatment the corrosion problem of water steam system can be addressed without taking the potential risk of oxygenated treatment using high concentration oxygen. Oxygenated treatment can significantly reduce the content of iron corrosion products especially those of suspended iron. The iron concentration of high pressure heater drainage is less than 1 μg/L after oxygenated treatment. Also air is the safest medium for oxygenated treatment, which has negligible influence on water quality(such as hydrogen conductivity and pH value).

Key words: feed water, high pressure heater, drainage, oxygenated treatment, water quality, water vapor system antisepsis

MENG Long, JIA Lan, ZHANG Wenshuai, YANG Shuiyang, LV Peng, LI Junwan. Research on Oxygenated Treatment for High Pressure Heater Drainage Water of Ultra Supercritical Units[J]. Electric Power, 2020, 53(6): 172-178.

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URL: https://www.electricpower.com.cn/EN/10.11930/j.issn.1004-9649.201902099

https://www.electricpower.com.cn/EN/Y2020/V53/I6/172

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