| SF6enclosed combination relay (GIS) is one of the lead power transmissionproducts with advance technology of the world. The high voltage switch tank is oneof its key components which is usually made in China by sand-shell moldingcasting resulting in leakage, low pass rate and high cost of the product. In thisthesis, the optimum design was proposed and its solidification process wasanalysed based on the low pressure casting technology to produce a type of100-0003GIS tank.Based on the low pressure casting characteristics, a lying tube-annular-gaptype casting system was adopted to solve the problem of filling difficulty. The UG3D modeling software and ProCAST simulation software were used numericalsimulate the casting process and solidification process of the high-voltageswitchgear aluminum alloy tank.There often exist shrinkage cavities in the products made by using the originalsand-shell-molding. Through numerical simulation for different process, it wasdetermined to add a rib plate on each side of the circular lug at the bottom of thecasting with the lying casting system. To satisfy the making the top lugs’solidification sequence later than that of the sprue runner and eliminating theshrinkage porosity.According to the simulation results to the different pouring temperature andfilling pressure, the defect forming causes during solidification process wasanalysed, a method to predict the defects was proposed, and new technicalparameters to produce the aluminum alloy tank were determined to be a pouringtemperature of700℃and a filling pressure of0.023MPa. |
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