传热学与电学问题的迁移类比研究:(2)工程实践

Analogical Transfer between Heat Transfer and Electrology:(2)Engineering Practices

为验证传热学与电学迁移类比理论研究成果的可行性与工程实践价值,给出了两个利用热电类比思想解决电气工程领域实际问题的典型应用案例。针对特殊区域电缆载流量合理核算的难题,基于热电类比分析思路构建电缆径向热路,将电缆结构的各层绝缘材料热阻与各层损耗进行归算,建立了穿过不利散热区电缆的分布式参数热路模型,给出了求解电缆温度场与载流量的思路,弥补了当前国际电工委员会(IEC)标准推荐计算方法的不足;针对变压器热点温度预测方法不能同时满足实时性与准确性的问题,结合变压器传热过程分析与热电类比理论构建了变压器的集中式参数热路模型,将基尔霍夫电流定律类比应用于热路模型,提出了热点温度快速预测方法。实例分析发现,所提模型相较于IEC推荐方法具有更高的预测精度。热电类比方法能有效地解决电气工程领域的实际应用问题,迁移类比学习应可推动不同学科交叉的创新与发展。

To verify the feasibility and engineering practice value of the transfer analogy theory between heat transfer and electrology,this paper presents two typical applications addressing practical problems in the field of electrical engineering.Firstly,in view of lack of calculating method for the current carrying capacity of cable lying through unfavorable heat dissipation regions,we establish the radial thermal circuit of cable with the aid of thermal-electrical analogy analysis.The thermal resistance of insulating material and the loss in each layer of cable structure are equivalently evaluated,and further,the thermal circuit model with distributed parameters is constructed.The thought of solving the cable temperature distribution and carrying capacity is given,which compensates the insufficiency of the current calculation method recommended by IEC standard.Secondly,for the limitations of the prediction methods of hot-spot temperature in transformer,we develop the thermal circuit model with centralized parameters by incorporating the heat transfer process of transformer and the thermal-electrical analogy.Applying Kirchhoff current law to the thermal circuit model,a faster prediction method for calculating the hot-spot temperature is proposed.It is verified that the model has higher prediction accuracy than the method recommended by IEC standard.The results indicate that the thermal-electric analogy can solve engineering problems more practically and the transfer analogy can promote innovation and development of many interdisciplinary researches.