Preparation And Study On Dissolved Gas Characteristics Of Hollow Fiber Membrane Doped With Nano-Oxide Al₂O₃

Large power transformers are the hub of power system equipments. To ensure thesafe operation of the transformer, it’s important to take real-time monitoring operationof type and content changes of the dissolved gas in transformer oil.The technology ofoil-gas separation is the key technology to the online monitoring of dissolved gas in theoil of transformer. It has important significance in the in-depth study of the onlinemonitoring of oil penetration technology, which improves the sensitivity, stability, lifeand simplifies online monitoring device structure.On the basis of the gas permeation techniques status about dissolved gases intransformer oil, the thesis studies the mechanism of modified hollow fiber membranesand gas permeability principles in the hollow fiber membrane; the paper proposespreparation of hollow fiber membrane doped nano-oxide Al2O3, which takespolytetrafluoroethylene、polyvinylidene fluoride、 poly hexafluoropropylene as rawmaterial and based on L-S method. Through the characterization of membranestructure,the paper analysis the influence on structure and properties of hollow fibermembrane doped nano-Al2O3, the factors include content of Al2O3、distance of dryspine、core concentration、bath temperature and so on. Also, the paper studiespermeability characteristics of oil-gas in hollow fiber membrane doped nano-Al2O3through building the lab platform.①The appropriate amount of doped A12O3can significantly change the surfacestructure of the membrane, improve the structure and performance of the hollow fibermembranes; increase stem-distance, weak the outside diameter and wall thickness; addthe outer surface pore size, appear sponge-like structure in intermediate layer; addDMAC core solution concentration, thicken intermediate foam layer, weak the hole inthe finger; rise the coagulation fluid temperature, first increase then reduce the waterflux of the membrane. The paper prepares hollow fiber membrane doped Al2O3bycombining doping research.②The paper builds experimental platform about the oil-gas permeability on thebase of gas permeation experiments in hollow fiber membrane; The paper takes in-depthresearch on permeability characteristics of oil-gas in hollow fiber membrane dopednano-Al2O3. Comparing the experimental results of oil-gas separation with the undopedhollow fiber membrane and oscillation degassing, we can draw the conclusion: oilosmotic equilibrium time decreases, and oil and gas separation increases. ③Through the research on temperature oil and the flow rate which influencesoil-gas permeation in hollow fiber membrane doped nano Al2O3, it shows that: therange of temperature is restricted in the effect on oil-gas separation capacity in thenano-oxide (Al2O3) hollow fiber membrane; with the increasing of oil flow rate, the gasconcentrations of the seven characteristics transformer oil are first increased thenstabilized. At the same conditions of temperature and pressure, nano-oxide hollow fibermembrane significantly increases oil-gas permeability characteristics. It lays technicalfoundation on the improvement of monitoring sensitivity in transformer oil dissolvedgas, and great application on on-line monitoring.