LBM simulation of heat transfer processes inside GIS capsule filled with different insulation gas mixtures

摘要

Lattice Boltzmann method (LBM) scheme is adopted to simulate the heat transfer processes inside isolated phase and three-phase enclosure gas insulated switchgear (GIS) capsules. D2Q9 fluid flow and thermal Lattice Boltzmann equations (LBEs) are solved through streaming and collision processes. Buoyancy force driven by natural convection is considered by the Boussinesq model. Power losses and thermal boundary conditions are obtained from closed formulas. Numerical results by LBM simulations are compared with those from physical experiments and conventional CFD simulations. Results show that LBM scheme could provide a simple and efficient alternative tool in the flow-thermal simulation of GIS equipment with desirable accuracy. Thermal performances of GIS capsule filled with different insulation gas mixtures (SF6, N2, CF4, CO2, CF3I) are then analyzed. Results show that upper conductors of three-phase GIS has larger temperature rise than lower conductor due to the natural convection effect. Conductor temperature rise inside gas mixture increases with the increase of second gas (N2, CO2, CF4) fraction. The thermal performance of GIS capsule could be reduced with the presentation of insulation gas mixtures.