Journal of South China University of Technology(Natural Science Edition) ›› 2023, Vol. 51 ›› Issue (7): 1-11.doi: 10.12141/j.issn.1000-565X.220754

Special Issue: 2023年机械工程

• Mechanical Engineering • Previous Articles     Next Articles

Design and Optimization of Liner TIG Welding Gun for Nuclear Heat Transfer Tube with Small Diameter

WANG Zhenmin1 XIE Huimin1 LI Xuyan1 WU Haodong1 ZHANG Mengjin2 WANG Xuezhu2 ZHANG QinTIAN Jiyu1   

  1. 1.School of Mechanical and Automotive Engineering,South China University of Technology,Guangzhou 510640,Guangdong,China
    2.China Nuclear Power Technology Research Institute Co. ,Ltd. ,Shenzhen 518000,Guangdong,China
  • Received:2022-11-17 Online:2023-07-25 Published:2023-03-07
  • Contact: 田济语(1991-),男,博士,助理研究员,主要从事核级焊接装备研究。 E-mail:tianjiyu@scut.edu.cn
  • About author:王振民(1974-),男,博士,教授,博士生导师,主要从事新型焊接电源、水下机器人制造等研究。E-mail:wangzhm@scut.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(U2141216);the Science and Technology Planning Project of Guangdong Province(2021B1515420006)

Abstract:

As China’s nuclear industry enters the third 30 years of development, the maintenance need for nuclear equipment is becoming increasingly urgent. The internal structure of the nuclear steam generator is complex, and the key structure, namely the heat transfer tube, has the restrictions like small diameter, long pipeline and difficult disassembly and installation, which make traditional repair methods extremely difficult in implementation. In order to solve the problem of corrosion damage of small-diameter nuclear heat transfer tube due to long-term high temperature and high pressure condition, an all-position automatic TIG welding gun for liner repair was designed in this paper, and the gun reliability verification and welding repair test were carried out. Firstly, the overall structure design of the welding gun was presented, and the advantages of the designed welding gun comparing with the traditional tungsten electrode TIG welding gun were described. Next, the design and verification of the welding gun transmission system with small size and high space utilization were completed. Then, the stiffness of the key part of the welding gun, namely the conductive shaft, was modelled, analyzed and calculated, and the reliability of the theoretical model was verified by finite element solution. On this basis, an optimization method of the welding gun structure was proposed. Moreover, the field test of deflection and the welding test were carried out, finding that the stiffness of the conductive shaft satisfies the field welding conditions. Finally, linear regression equations and deflection correction formulas were used to quantitatively predict the deflection of the welding gun, and the results verify the rationality of the designed structure. Welding tests results show that the rotation speed of the transmission system is stable and controllable in working condition of welding gun, and the welding seam is well formed. The developed liner welding gun can satisfy the requirements of liner welding repair of the stainless-steel heat transfer tube inside the nuclear steam generator.

Key words: small-diameter heat transfer tube, welding gun, stiffness modelling, finite element, liner welding

CLC Number: