Journal of South China University of Technology(Natural Science Edition) ›› 2023, Vol. 51 ›› Issue (6): 119-128.doi: 10.12141/j.issn.1000-565X.220349

Special Issue: 2023年能源、动力与电气工程

• Energy,Power & Electrical Engineering • Previous Articles     Next Articles

Numerical Simulation of Thermal Ratcheting of Triple Eccentric Butterfly Valve

LI Shuxun1,2 ZHANG Jianzheng1,2 YIN Huiquan3 KANG Wenyu1,2 ZHANG Bohao1,2 WANG Yixue1,2   

  1. 1.School of Petrochemical Engineering,Lanzhou University of Technology,Lanzhou 730050,Gansu,China
    2.Machinery Industry Pump and Special Valve Engineering Research Center,Lanzhou 730050,Gansu,China
    3.Shaanxi Blue Arrow Space Technology Co. ,Ltd. ,Xi’an 710199,Shaanxi,China
  • Received:2022-06-06 Online:2023-06-25 Published:2022-09-30
  • Contact: 李树勋(1973-),男,教授,主要从事特殊阀门研究。 E-mail:gdlishuxun@126.com
  • About author:李树勋(1973-),男,教授,主要从事特殊阀门研究。
  • Supported by:
    the Science and Technology Program Funding of Gansu Province(22CX8GA125)

Abstract:

In order to study the effect of thermal ratcheting on the thermal deformation and sealing performance of the triple eccentric metal hard seal butterfly valve, this paper firstly excluded the possibility of plastic collapse failure of the butterfly valve and fatigue failure of the sealing structure under several alternating cyclic loads at room temperature and high temperature. ANSYS Workbench finite element analysis software was adopted to study the thermal ratcheting effect of the triple eccentric metal hard seated under alternating cyclic loading at room and elevated temperature, and ten times of temperature cyclic loading analysis were performed on the butterfly valve based on Chaboche nonlinear kinematic hardening model. The results show that the maximum temperature difference between the inner ring surface of the valve seat and the outer wall of the valve body is about 60 ℃ under high temperature conditions. After the temperature is reduced to room temperature, the maximum plastic strain of the valve seat increases with the increase of cycle times. The maximum plastic strain of the valve seat after 10 temperature cycles is 0.021 16, and the thermal ratcheting effect occurs under the action of temperature cyclic load. After the fifth temperature alternating cycle, the maximum radial deformation of the valve seat and the sealing ring is 0.284 4 mm and 0.275 3 mm respectively. The maximum radial deformation of the valve seat is greater than that of the sealing ring. The residual deformation of the valve seat leads to the gap of the sealing surface, which proves that the sealing failure of the triple eccentric butterfly valve is caused by the thermal ratchet effect of the valve seat. After applying good thermal insulation on the exterior wall of the valve body, the ratcheting effect of the valve seat does not occur according to finite element calculation, indicating that good thermal insulation on the valve body is an effective means to avoid sealing failure caused by ratcheting effect of the valve seat. The research results reveal the reasons for the sealing failure of the butterfly valve under several alternating cyclic loads at room temperature and high temperature, and this paper puts forward corresponding preventive measures, which is of great guiding significance for other types of valves and pressure pipelines under the same working conditions to avoid thermal ratcheting effect.

Key words: triple eccentric butterfly valve, thermal ratcheting, Chaboche model, cyclic loading, sealing

CLC Number: