Ammonia corrosion analysis of copper tubes and experimental research on non-copper improvement for heat exchanger in power plant  

作　　者：ZENG Zhou-hua LONG Xin-feng LIANG Ping 

机构地区：[1]Department of Chemistry, Huanggang Normal University, Huanggang 438000, Hubei P.R. China [2]School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640, P.R. China [3]School of Electricity Power, South China University of Technology, Guangzhou 510640, P.R. China

出　　处：《Journal of Chemistry and Chemical Engineering》2009年第12期30-36,共7页化学与化工（英文版）

摘　　要：Ammonia corrosion in copper tube will affect the safety of boiler running in power plant. Therefore, no copper in heating system has become a technical orientation in heat exchanger reconstruction, This paper analyzes the condition and mechanism of ammonia corrosion occurring in copper tube used in coal-fired power plants. Using a general steam condensation testing equipment only for horizontal single tube, with water vapor and water as working fluid, on two types of steel tube with 2-side enhancement heat transfer, namely, a spirally fluted tube and a ratchet tube with internal spiral groove （RISG tube） which was developed recently, a set of experimental tests are conducted to investigate the characteristics of heat transfer and hydromeehanics. In order to compare easily, both one copper smooth tube and one steel smooth tube are also used in the experiment. The experimental results, which get from single horizontal tube, show that the overall heat transfer coefficient of steel spirally fluted tube are improved by 10%o to 17%, and that of the steel RISG tube（22%-28%） is better than steel spirally fluted tube, its flow resistance coefficient is only increased by 22% to 66% when compared with smooth tube. Based on a lot of experimental data, the steel spirally fluted tube and the steel RISG tube were applied in a low pressure preheater and an oil-cooler of some or other power plant respectively. The field testing results showed that their heat transfer coefficient with each types of enhancement heat transfer tubes were improved by 2.5% and 21%-45% comparing with copper smooth tube heat exchangers. Both basic and field experiment indicates that the steel tube with 2-side enhancement heat transfer is an ideal choice for heat exchanger reconstruction in no copper issue in power plants.

关 键 词：spirally fluted tube ratchet tube with internal spiralgroove heat transfer enhancement copper corrosion low-pressure preheater oil cooler no copper in heating system 

分 类 号：TK172[动力工程及工程热物理—热能工程] X773[环境科学与工程—环境工程]