【作者】 邓皓月；

【导师】 张云怀； 肖鹏；

【作者基本信息】 重庆大学 ， 分析化学， 2011， 硕士

【摘要】 矿物油具有良好的冷却性能、电气绝缘以及低廉的成本,在油浸绝缘高电压设备中已经有一个多世纪的应用历史,但是其燃点、闪点低,不能满足高防火性能的要求,并且难以生物降解,一旦泄漏就会造成污染。因此,研究耐高温、高介电常数、可生物降解且成本适中的植物绝缘油成为国内外关注的热点课题;植物油的闪点普遍高于300℃,满足难燃油的要求,生物降解率大于97%,即使发生泄漏也不会对水源、居住环境等造成污染,在兼顾成本、生物降解性和原料来源等方面都占有优势,因此在利用基因技术研究高产、高品质植物油料作物取得突破和石油枯竭的新形势下,它将很有潜力成为矿物油的绿色替代品。本文在对国内外植物绝缘油研究现状总结分析的基础上,探索了将菜籽油提炼为绝缘油的精炼工艺和方法,通过试验研究了精炼后菜籽绝缘油的各项理化、电气性能及其用作绝缘油的优缺点;系统测定了在不同温度、时间和水油比条件下的水解动力学数据,使用Arrhenius公式作为表征总反应实验速率系数与反应温度关系的经验定律;并进一步测试了菜籽绝缘油在不同水解程度下的工频击穿电压、介频电谱及体积电阻率等介电性能,以考核它能否作为液体绝缘材料,为菜籽油用作基础油的液体绝缘介质的开发奠定了基础,填补了国内在植物绝缘油研究上的空白。研究发现,在选择基础油时,从植物油的化学组成和分子结构出发,以油酸含量高的菜籽油为最佳。通过对菜籽油精炼步骤中主要试验条件的控制,可将菜籽油的酸值控制在0.03mgKOH·g-1以下,击穿电压达到60kV以上,其理化及电气性能均达到GB2536-90《变压器油》的要求。实验数据显示,在10-2～106Hz的试验频率范围内,在不同水解程度下精炼后的菜籽绝缘油的介电常数、介质损耗、体积电阻率均随频率的升高而降低,其电气性能均发生了规律性的变化,对绝缘性能产生了不同程度的影响,本文从分子结构和电场作用的角度分析了在水解过程中其各项介电性能变化的机理,为进一步探讨植物绝缘油在变压器运行中的老化问题提供基本依据。更多还原

【Abstract】 Mineral insulating oil has excellent high coolant capability and electric insulating property and low cost,it has played important roles in oil-immersed high voltage equipment more than a century. But its burning and flash points are too low to satisfy the requirement of fireproofing. At the same time,it is poorly biodegradable and may contaminate soil and resident conditions when serious oil leakage occurs. Therefore research of the environment-friendly vegetable insulating oil with high flash point and high biodegradable percent has become a pop project;Flash point of vegetable insulating oil is higher than 300℃, it is a fire resistant oil;its biodegradable percent is larger than 97%,it will not pollute the water and inhabited area. Nowadays,the output and quality of oil corps are improved by using gene techniques,and the reserves of mineral oil become decreased,so vegetable insulating oil could be the green substitute as mineral oil.In this paper, the domestic and overseas research situation of vegetable insulating oil was summarized and analyzed; explored the methods how to refine the vegetable oil to dielectric liquid;based on the test researching results,the advantage and disadvantage of rape-seed oil for using as insulating oil was also researched. The hydrolysis dynamic of rape-seed insulation oil was systematically studied at different temperatures,reaction times and water-oil ratio,The variation between the hydrolysis degree of insulating oil and reaction temperature was determined using the Arrhenius Empirical equation;and the series dielectric properties of vegetable insulating oil under different hydrolysis degree was tested : AC-breakdown voltage , relative permittivity and dielectric dissipation. This paper is the groundwork of using rape-seed oil as dielectric liquid and filled up the blank of vegetable insulating oil studies in domestic study.The investigation shows,according to the chemical composition and molecular structure of vegetable oil,rape-seed oil high in oleic acid is the best choice as base oil. Controlling the dominating testing conditions in vegetable oil refined processes, and using repeated refined method, the acid value of vegetable oil can be limited under 0.03mgKOH·g-1,the AC-breakdown voltage has reached more than 60kV,and the physical,chemical and electrical properties of vegetable oil met the requirements of standard GB2536-90 <Transformer oil>.From the experiment data,the electrical properties of refined insulating oil changed regularly under different hydrolysis degree,insulating properties were influenced inordinately. According to the chemical molecular structure and the influence of electric field,the mechanism of the change of electrical properties are analyzed,and they provide experiment basis for the ageing problems of vegetable insulating oil in transformer operation.更多还原