Monitoring and Simulated Experiments of Oxidation-Reduction Potential of Boiler Feedwater at High Temperatures

doi:10.11902/1005.4537.2017.155

Journal of Chinese Society for Corrosion and protection

2018, Vol. 38

Issue (5): 487-494 DOI: 10.11902/1005.4537.2017.155

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Monitoring and Simulated Experiments of Oxidation-Reduction Potential of Boiler Feedwater at High Temperatures

Yue QIAO, Zhiping ZHU(

), Lei YANG, Zhifeng LIU

Hunan Provincial Key Laboratory of Materials Protection for Electric Power and Transportation, School of Chemistry and Biological Engineering, Changsha University of Science and Technology, Changsha 410004, China

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Abstract

Oxidation reduction potential (ORP) measurement can be an effective means for maintaining the state of feedwater for power station to be oxidizing, neutral, or reducing. In order to investigate the characteristics of ORP and its correlation with metal corrosion in high temperature water, a series of experiments including electrochemical measurement and simulated corrosion experiment were carried out. The results show that the ORP increases with the increase of dissolved oxygen content, while decreases with the increase of pH and temperature. Besides the flow rate has no effect on the ORP. It follows that ORP measurements for high-temperature and -pressure waters, as compared to the ones for low-temperature ORP waters, can act as a more sensitive and accurate method to effectively detect the trace amount of dissolved oxygen. In summary, ORP measurements can be used to understand, monitor and control the corrosion of steels in feedwater.

Key words: oxidation reduction potential dissolved oxygen content pH value 20# carbon steel high-temperature feedwater environment

Received: 27 September 2017

ZTFLH:

TG172.4

Fund: Supported by Key Project of Hunan Science and Technology Plan (2013GK2016) and Hunan Postgraduate Research and Innovation Project (CX2017B488)

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Yue QIAO, Zhiping ZHU, Lei YANG, Zhifeng LIU. Monitoring and Simulated Experiments of Oxidation-Reduction Potential of Boiler Feedwater at High Temperatures. Journal of Chinese Society for Corrosion and protection, 2018, 38(5): 487-494.

URL:

https://www.jcscp.org/EN/10.11902/1005.4537.2017.155 OR https://www.jcscp.org/EN/Y2018/V38/I5/487

Fig.1 Dynamic simulating apparatus for ORP measurementat high temperature

Fig.2 Effect of oxygen concentration on ORP at various temperatures

Fig.3 Relationships of ORP and lgDO at various temperatures

Table 1 Fitting equations of ORP-lgDO at various temperatures

Fig.4 Variations of ORP with dissolved oxygen concentration at various temperatures

Fig.5 Effect of pH on ORP at 25 ℃ in water containing various oxygen concentrations

Fig.6 Effect of pH on ORP at high temperatures

Table 2 Fitting equations of ORP-pH at various temperatures

Fig.7 Variations of ORP with flow of water containing various oxygen concentrations at 80 ℃

Fig.8 ORP as a function of temperature in water containing 10 μgL^-1 oxygen (DO=10 μg/L, pH=9.0)

Fig.9 ORP as a function of dissolved oxygen and pH at various temperatures

Table 3 Fitting equations of ORP-DO -pH at various temperatures

Table 4 Wilcoxon test results of the calculated and measured values of ORP at 80 ℃

Table 5 Wilocoxon test results of the calculated and measured values of ORP at 120 ℃

Fig.10 Potential-pH diagram of Fe-H₂O system at 80 ℃

Fig.11 Potential-pH diagram of Cu-H₂O system at 80 ℃

Fig.12 Relationship diagram of the corrosion potential of 20# steel and ORP at different corrosion time

[1]	National Energy Administration.DL/T 1480-2015 Test method for oxidation-reduction potential of water [S]. Beijing: China Electric Power Press, 2015(国家能源局. DL/T 1480-2015 水的氧化还原电位测量方法[S].北京: 中国电力出版社, 2015)
[2]	Macdonald D D.Viability of hydrogen water chemistry for protecting in-vessel components of boiling water reactors[J]. Corrosion, 1992, 48: 194
[3]	Macdonald D D.Redox potential measurements in high temperature aqueous systems[J]. J. Electrochem. Soc., 1981, 128: 250
[4]	Jones R L, Nelson J L.Hydrogen water chemistry for BWRs: A status report on the EPRI development program[J]. Nucl. Eng. Des., 1990, 124: 33
[5]	Hicks P D, Grattan D A.Method and device for creating and analyzing an at temerature and pressure oxidation-reduction potential signature in hot water systems for preventing corrosion [P]. US Pat, US7955853, 2011
[6]	Gray D M.The role of dissolved oxygen and ORP measurements in power plant chemistry[J]. Power Plant Chem., 2008, 10: 320
[7]	Olson V G.Evaluating on-line high purity water oxidizing-reducing potential analysis for boiler feedwater quality[J]. Power Plant Chem., 2010, 12: 110
[8]	Gray D M.Practical quality assurance of on-line analytical measurements[J]. Power Plant Chem., 2010, 12: 492
[9]	Lendi M, Wuhrmann P.Impact of film-forming amines on the reliability of online analytical instruments[J]. Power Plant Chem., 2012, 14: 560
[10]	Hicks P D, Grattan D A, White P M, et al.Feedwater redox stress management: a detailed @T ORP? study at a coal-fired electric utility[J]. Power Plant Chem., 2007, 9: 324
[11]	Zheng L L, Dong J, Li H B, et al.Optimization of oxidation - reduction potential in water [A]. Annual Meeting of the Chinese Society for Environmental Science[C]. Haikou, 2016: 1045(郑琳琳, 董捷, 李海滨等. 水中氧化还原电位测定方法优化 [A]. 2016中国环境科学学会学术年会[C]. 海口, 2016: 1045)
[12]	Kerner Z, Balog J, Nagy G.Testing of high temperature reference electrodes for light water reactor applications[J]. Corros. Sci., 2006, 48(8): 1899
[13]	Xiang J, Xu L P, Li H P, et al.Research on and application of oxidation-reduction potential[J]. Earth Environ., 2014, 42: 430(向交, 徐丽萍, 李和平等. 氧化还原电位的研究及应用[J]. 地球与环境, 2014, 42: 430)
[14]	Xu H C, Xu X J, Wang K, et al.An analysis of factors affecting the oxidation reduction potential in drinking water[J]. J. Univ. Sci. Technol. Suzhou (Eng. Technol.), 2007, 20(2): 63(徐华成, 徐晓军, 王凯等. 饮用水氧化还原电位的影响因素分析[J]. 苏州科技学院学报(工程技术版), 2007, 20(2): 63)
[15]	Huang Q, Song J X, Wang S H, et al.Influencing factors of ORP measurement for reverse osmosis influent water in thermal power plants[J]. Ind. Water Treat., 2015, 35(6): 75(黄茜, 宋敬霞, 汪思华等. 火电厂反渗透进水ORP测量的影响因素[J]. 工业水处理, 2015, 35(6): 75)
[16]	Hoare J P.On the interaction of oxygen with platinum[J]. Electrochim. Acta, 1982, 27: 1751
[17]	Niedrach L W, Stoddard W H.Corrosion potentials and corrosion behavior of AISI 304 stainless steel in high-temperature water containing both dissolved hydrogen and oxygen[J]. Corrosion, 1986, 42: 696
[18]	Jia J M, Chen J G, Li Z G, et al.Countermeasures against massive exfoliation of oxidation scale on the internal surface of coarse grained 18-8 type stainless steel boiler tubes[J]. Electr. Power, 2008, 41(5): 37(贾建民, 陈吉刚, 李志刚等. 18-8系列粗晶不锈钢锅炉管内壁氧化皮大面积剥落防治对策[J]. 中国电力, 2008, 41(5): 37)
[19]	Lu J T, Gu Y F.High-temperature steam oxidation behavior of alloys used for key parts of the power plant boiler[J]. J. Chin. Soc. Corros. Prot., 2014, 34: 19(鲁金涛, 谷月峰. 电站锅炉关键部件材料高温蒸汽氧化研究进展[J]. 中国腐蚀与防护学报, 2014, 34: 19)
[20]	Liu C H, Shi G Z.Study on accurate control of feed-water oxygenated treatment for capital construction 1000 MW ultra-supercritical unit[J]. Technol. Water Treat., 2013, 39(6): 109(刘春红, 施国忠. 基建超超临界1000 MW机组精确给水加氧处理技术的研究[J]. 水处理技术, 2013, 39(6): 109)
[21]	Chen T Y, Moccari A A, Macdonald D D.Development of controlled hydrodynamic techniques for corrosion testing[J]. Corrosion, 1992, 48: 239
[22]	Macdonald D D, Lin C C.Discussion on "electrochemical potential measurements under simulated BWR water chemistry conditions"[J]. Corrosion, 1993, 49: 90
[23]	Eason E D.Modeling ECP of stainless steel in simulated BWR environments with hydrogen peroxide addition [R]. Palo Alto, CA: Electric Power Research Institute, 1991
[24]	Shu Y D, Yang X Y.Modern Electrochemical Research Methods [M]. Changsha: Central South University Press, 2015: 34(舒余德, 杨喜云著. 现代电化学研究方法 [M]. 长沙: 中南大学出版社, 2015: 34)
[25]	Zhou B Q, Chen Z H.Water Treatment in the Thermal Power Plant [M]. 4th Ed.,Beijing: China Electric Power Press, 2009: 595(周柏青, 陈志和. 热力发电厂水处理 [M]. 第4版. 中国电力出版社, 2009: 595)

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