Chemical Cleaning for Inner Cooling System in Generator with High Content Copper Deposition

doi:10.11930/j.issn.1004-9649.201711006

Abstract

Abstract: Insulation deterioration and cooling capacity decrease due to corrosion and deposition of corrosion products in inner cooling water system are potential threats to generator operation. At a power plant of Hunan Province, abnormal temperature and blockage are observed in the generator inner cooling water system with high content copper in the corrosion products. To address the potential issues, chemical cleaning is carried out for the first time by using amino sulfonic acid based composite acid with the addition of hydrogen peroxide in combination with multi-step rinse process to eliminate copper oxides and copper. The results indicate that, by taking advantage of this technology the inner corrosion products are effectively cleared with very few damages to the stator bar. The before and after comparison shows that the temperature of stator winding during operation was reduced up to 9.9℃. The maximum temperature difference between stator coil bars is reduced by 10℃, while the maximum temperature difference between the water outlets from stator coil bars dropped by 11℃, respectively. In this way the secure and economical operation of generator can be ensured.

Key words: generator, stator cooling, corrosion, copper, copper oxides, chemical cleaning, amino sulfonic acid

CLC Number:

TM621.8

WU Junjie, LIU Kai, ZHOU Zhou, ZHA Fanglin, FENG Bing, WAN Tao, XU Song, GONG Shangkun. Chemical Cleaning for Inner Cooling System in Generator with High Content Copper Deposition[J]. Electric Power, 2018, 51(11): 15-19,184.

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URL: https://www.electricpower.com.cn/EN/10.11930/j.issn.1004-9649.201711006

https://www.electricpower.com.cn/EN/Y2018/V51/I11/15

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