菜籽油酯交换制备植物绝缘油及电气性能研究

菜籽油与甲醇在氢氧化钠的催化下通过酯交换反应制得菜籽绝缘油。结果表明，最佳酯交换工艺条件为：醇油摩尔比为9：1，催化剂用量为油质量的0．4％，反应温度为60℃，反应时间为75min，转化率为94．89％；最佳精炼工艺条件为：活性白土吸附脱色的用量为5％，搅拌时间为25min，搅拌温度为80℃，碱性氧化铝吸附降酸值温度为60℃，时间为60min；所得菜籽绝缘油闪点为160℃，酸值为0．025mgKOH／g，工频击穿电压达到55．5kV，90℃介质损耗为0．010，90℃体积电阻率为21．8GΩ·m，相对介电常数ε，为2．839。

Study on electrical performance of vegetable insulating oils prepared by ester-exchange reaction from rapeseed oil

The insulation oil of rapeseeds is generally prepared by ester-exchange reaction with base as a catalyst between rapeseeds oil and methanol. The results indicated that the optimum conditions for preparation was： alcohol-oil ratio 9：1, the amount of catalyst 0.4%, reaction temperature 60℃, reaction time 75 min, and the conversion rate could reach 94.89% under this conditions. The optimum refining technological conditions was that amount of active clay 5% for adsorption and decolorization, stirring time 25 min, the stirring temperature 80℃ ,60℃ for adsorption temperature to reduce acid value with alkaline alumina, adsorption time 60 min. The results of physicochemical and electrical performance tests showed that 160℃ for flash points,0. 025 mg KOH/g for acid value,55.5 kV for power frequency breakdown voltage ,0.010 for dielectric loss at 90 ℃, 21.8 GΩ· m for volume resistivity at 90℃ ,2.839 for relative dielectric constant.