海水淡化用薄壁卷焊钛管传热及耐蚀性能

doi:10.16085/j.issn.1000-6613.2018-2270

摘要/Abstract

摘要：

采用TIG自动卷焊工艺制备了?22mm×0.4mm规格的薄壁卷焊TA2传热管，借助低温多效蒸馏海水淡化中试平台开展了薄壁卷焊钛管在海水应用环境中的传热及耐蚀性能实验研究。采用失重法分析评价了其耐腐蚀性能，并与标准规格?22mm×0.5mm无缝钛管在耐腐蚀性能、投资经济性方面进行了对比。结果表明：在低温多效海水淡化实际应用条件下，薄壁卷焊钛管总传热系数可达3400W/(m²·K)以上；在降膜蒸发喷淋冲刷及浓海水高温高湿腐蚀环境中，薄壁卷焊钛管与无缝钛管具有同等优良的耐海水腐蚀性能，年平均腐蚀速率小于0.0003mm/a，焊缝处也未发现点蚀现象，能满足实际海水淡化工程对材料的应用要求。相比于传统无缝钛管，同等传热面积条件下，薄壁卷焊钛管能使海水淡化传热材料投资降低25%以上，在海水淡化、石油化工等领域应用前景广阔。

关键词: 海水淡化, 薄壁卷焊钛管, 传热系数, 耐腐蚀性, 经济性分析

Abstract:

One type of ?22mm×0.4mm thin-wall welded titanium tube was developed using Tungsten Inert Gas (TIG) curling-welding technology. Heat transfer and corrosion resistance experiments on this kind of tube were conducted in the circumstance of practical desalination operating conditions based on the LT-MED pilot scale test platform. Weight loss method was adopted to evaluate the resistance to seawater corrosion of titanium tube. The ?22mm×0.4mm thin-wall welded titanium tube was compared with ?22mm×0.5mm rolled seamless titanium tube in terms of corrosion resistance and service economy. The results indicated that the total heat transfer coefficient of falling film evaporator with thin-wall welded titanium tube would be over 3400W/(m²·K) in the LT-MED experimental conditions, and the thin-wall welded titanium tube had the same excellent corrosion resistance as rolled seamless titanium tube in the operating environment of falling film flow of seawater and high temperature and high humidity corrosion of brine. The annual mean corrosion rate was less than 0.0003mm/a. No pitting corrosion was found at welded seams during the testing process. The utilization requirements validity of thin-wall welded titanium tube for desalination was verified. Comparing with the usual rolled seamless titanium tube, the spread application of thin-wall curling-welding titanium tube in the LT-MED device can greatly decrease investment cost of heat transfer tube by more than 25% under the same heat transfer area. The research results show that thin-wall welded titanium tube have an extensive application prospect in the field of thermal desalination and petrochemical engineering.

Key words: desalination, thin-wall welded titanium tube, heat transfer coefficient, corrosion resistance, economic analysis

中图分类号:

P747.1

吕宏卿,王鑫,刘洪锟,邢玉雷,韩旭,齐春华,徐克,李华. 海水淡化用薄壁卷焊钛管传热及耐蚀性能[J]. 化工进展, 2019, 38(08): 3556-3561.

Hongqing LÜ,Xin WANG,Hongkun LIU,Yulei XING,Xu HAN,Chunhua QI,Ke XU,Hua LI. Heat transfer and corrosion resistance experiments of thin-wallcurling-welding titanium tube for desalination[J]. Chemical Industry and Engineering Progress, 2019, 38(08): 3556-3561.

图/表 12

参考文献 18

1	林文珠, 曹嘉豪, 方晓明, 等 . 管壳式换热器强化传热研究进展[J]. 化工进展, 2018, 37(4): 1276-1286.
	LIN W Z , CAO J H , FANG X M , et al . Research progress of heat transfer enhancement of shell-and-tube heat exchanger[J]. Chemical Industry and Engineering Progress, 2018, 37(4): 1276-1286.
2	ZHAO C Y , JI W T , HE Y L , et al . A comprehensive numerical study on the subcooled falling film heat transfer on a horizontal smooth tube[J]. International Journal of Heat and Mass Transfer, 2018, 119: 259-270.
3	DEYAB M A . Corrosion inhibition of heat exchanger tubing material (titanium) in MSF desalination plants in acid cleaning solution using aromatic nitro compounds[J]. Desalination, 2018, 439:73-79.
4	许莉, 王世昌, 王宇新, 等 . 水平管薄膜蒸发传热系数[J]. 化工学报, 2003, 54(3): 299-304.
	XU L , WANG S C , WANG Y X , et al . Heat-transfer coefficients of falling film horizontal tube evaporator[J]. Journal of Chemical Industry and Engineering (China), 2003, 54(3): 299-304.
5	TASEIDIFAR M , SHAHID M , PASHLEY R M . A study of the bubble column evaporator method for improved thermal desalination[J]. Desalination, 2018, 432: 97-103.
6	杨文甲 . 薄壁焊接钛管工艺及性能[J]. 中国有色金属学报, 1994, 4(4): 91-94.
7	YANG W J . Process and performance of thin-wall welding titanium tube[J]. Chinese Journal of Nonferrous Metals, 1994, 4(4): 91-94.
8	张峰 . 工业纯钛TA2激光焊接工艺及其气孔形成机理研究[D]. 镇江: 江苏科技大学, 2017.
	ZHANG F . Study on the mechanism of porosity formation and laser welding technology of commercial pure titanium TA2[D]. Zhenjiang: Jiangsu University of Science and Technology, 2017.
9	ABRAHAM R , MANI A . Heat transfer characteristics in horizontal tube bundles for falling film evaporation in multi-effect desalination system[J]. Desalination, 2015, 375: 129-137.
10	PALANIVEL R , LAUBSCHER R F , DINAHARAN I . An investigation into the effect of friction welding parameters on tensile strength of titanium tubes by utilizing an empirical relationship[J]. Measurement, 2017, 98: 77-91.
11	PALANIVEL R , DINAHARAN I , LAUBSCHER R F . Assessment of microstructure and tensile behavior of continuous drive friction welded titanium tubes[J]. Materials Science and Engineering: A, 2017, 687: 249-258.
12	WANG K H , LIU G L , ZHAO J , et al . Formability and microstructure evolution for hot gas forming of laser-welded TA15 titanium alloy tubes[J]. Materials & Design, 2016, 91: 269-277.
13	AUWAL S T , RAMESH S , YUSOF F , et al . A review on laser beam welding of titanium alloys[J]. The International Journal of Advanced Manufacturing Technology, 2018, 97(1/2/3/4): 1071-1098.
14	郭靖 . TA2钛管钨极氩弧焊焊接工艺及可靠性研究[D]. 天津: 天津大学, 2012.
	GUO J . Study on TIG welding procedure and reliability of TA2 commercial pure titanium pipe[D]. Tianjin: Tianjin University, 2012.
15	JI W T , CHONG G H , ZHAO C Y , et al . Condensation heat transfer of R134a, R1234ze(E) and R290 on horizontal plain and enhanced titanium tubes [J]. International Journal of Refrigeration, 2018, 93: 259-268.
16	中华人民共和国国家质量监督检验检疫总局, 中国国家标准化管理委员会 . 换热器及冷凝器用钛及钛合金管: GB/T 3625—2007[S]. 北京: 中国标准出版社, 2007.
	General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China, Standardization Administration of the People's Republic of China . Titanium and titanium alloy tube for condensers and heat exchangers: GB/T 3625—2007[S]. Beijing: Standards Press of China, 2007.
17	MALIK A U , AL-FOZAN S A , AL-MUAILI F . Corrosion of heat exchanger in thermal desalination plants and current trends in material selection[J]. Desalination and Water Treatment, 2015, 55(9): 2515-2525.
18	贾祥亚, 李德雨, 刘茵琪 . 替代无缝钛管的焊接钛管应用性能研究[J]. 材料开发与应用, 2014, 29(4): 40-42.
	JIA X Y , LI D Y , LIU Y Q . Application performance research of welded titanium tube for substitute seamless titanium tube[J]. Development and Application of Materials, 2014, 29(4): 40-42.

参数	蒸发器							冷凝器
参数	1效	2效	3效	4效	5效	6效	7效	冷凝器
蒸发温度/℃	69	66	63	60	57	54	51	48
加热蒸汽温度/℃	72	69	66	63	60	57	54	51
操作压力/kPa	29.88	26.13	22.88	19.91	17.33	15.00	12.98	—
料液盐度/g·kg^-1	59.2	58.7	57.1	57.1	57.5	55.3	55.8	33.8

参数	蒸发器							冷凝器
参数	1效	2效	3效	4效	5效	6效	7效	冷凝器
蒸发温度/℃	69	66	63	60	57	54	51	48
加热蒸汽温度/℃	72	69	66	63	60	57	54	51
操作压力/kPa	29.88	26.13	22.88	19.91	17.33	15.00	12.98	—
料液盐度/g·kg^-1	59.2	58.7	57.1	57.1	57.5	55.3	55.8	33.8

合金元素	质量分数/%
Fe	≤0.30
C	≤0.10
N	≤0.05
H	≤0.015
O	≤0.25
Ti	余量

合金元素	质量分数/%
Fe	≤0.30
C	≤0.10
N	≤0.05
H	≤0.015
O	≤0.25
Ti	余量

参数名称	数值
钨极直径/mm	?3.2
焊接电流/A	120～210
焊接电压/V	8～12
焊接速度/m·min^-1	3～5
喷嘴直径/mm	?17
喷嘴入射角/(°)	30～45
电弧长度/mm	2～3
氩气流量/L·min^-1	5
焊后热处理/℃	560～600