纳米改性变压器油的热分解活化能研究

Thermal Decomposition Energy of Nanoparticle Modified Transformer Oil

纳米改性技术在提高变压器油纸复合绝缘的击穿强度和老化性能方面已显示了极大的潜力,开展纳米材料改性变压器油(简称:纳米变压器油)热分解过程及其热稳定性的研究对于其实际应用至关重要。基于热反应动力学理论,采用热重法测试分析了Ti O2纳米变压器油在5种不同升温速率(5、10、15、20和25℃/min)下的热分解过程,利用微分法和积分法分别计算了纳米变压器油样的主要动力学参数。结果表明纳米变压器油的平均热分解反应活化能可达61.38 k J/mol,活化能的数值受计算方法的影响,其中FWO方法计算结果最为可信,其线性相关系数高达0.997 80,利用此方法计算得到的Ti O2纳米变压器油的热分解反应活化能为63.37 k J/mol。该研究结果表明纳米材料改性有利于提高变压器油的活化能,提高其热分解稳定性,这种方法为评估纳米变压器油的热稳定性及其综合性能提供了参考。

Nano-modification technique has shown a great potential in improving breakdown strength and aging property of transformer oil/ paper insulation system. The thermal degradation process and property of nanoparticle modified transformer oil （nanofluid） play an important role in its practical applications. Based on thermal degradation kinetics theory, thermal degradation process of Ti02 nanofluid is investigated by using thermogravimetric method （TG） under five heating rates （5, 10, 15, 20 and 25 ~C/min）. The main kinetic parameters of nanofluid is obtained respectively by using differential and integral method. The results indicate that mean activation energy of nanofluid is up to 61.38 kJ/mol and the obtained value is affected by the calculation methods. FWO method is more reliable than other methods with a emTelation coefficient up to 0.997 80. The activation energy of the TiO2 nanofluid calculated by FWO method is 63.37 kJ/mol. All these results illustrate that nanomaterial-modification can increase the activation energy of transformer oil and improve its thernml decomposition behavior. This method provides a basis for thermal stability evaluation and overall performance of nanofluid.