Abstract
The air arc impinging to chamber shell during interruption current process were studied by experiments and numerical simulation. Firstly, strain characteristics of chamber shell were measured by the strain gauge, and the strain changing with times were lagging behind the pressure in arc chamber. Experiment strain results 0.0035 and 0.0025 were slightly smaller than the calculation results 0.0055 and 0.0035. Furthermore, the thermal field mathematics model of chamber shell was proposed, and it was found that there was a large temperature gradient in the thickness of the chamber shell. Lastly, stresses-strains of three kinds of coupling methods, which were the fluid-structure coupling, the thermal-structure coupling and the fluid-thermal-structure coupling were compared. It was confirmed that the mechanical stress was concentrated in the middle of the side wall, while the maximum thermal stress was distributed on the vent area. Total stress and total strain were not equal to the algebraic sum of mechanical field and thermal field. The effect of different fixed supports on the thermal field was greater than the effect on the fluid field, and outer side wall fixed support had minimal displacement.
Highlights
When the arc of a low voltage circuit breaker (LVCB) is interrupted, the temperature and pressure in the arc chamber rise quickly
The high temperature and high pressure arc plasma acts on the inner wall of the arc chamber, causing arc chamber shell to produce higher local stress, deformation, even fracture under coupling of the flow field and the thermal field
The thermal field of the chamber shell was calculated by steady state and transient in turn
Summary
When the arc of a low voltage circuit breaker (LVCB) is interrupted, the temperature and pressure in the arc chamber rise quickly. The high temperature and high pressure arc plasma acts on the inner wall of the arc chamber, causing arc chamber shell to produce higher local stress, deformation, even fracture under coupling of the flow field and the thermal field. The coupling is called fluid-thermal-structure coupling when there is a highly nonlinear coupling with the fluid flow field, the temperature field, and the structural field in the system. Fluid-structure coupling ignores the influence of temperature field, and is usually divided unidirectional and bidirectional.. Unidirectional ignores the effect of solid deformation on the flow field. As the deformation of the arc chamber housing is so small that it nearly has no effect on the internal gas flow field, unidirectional coupling was adopted. The stress and displacement of the arc chamber shell were calculated after the pressure under different arc current had been obtained
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.