油浸式变压器分体冷却装置模拟试验研究

Research on Simulation Test of Separated Cooling Installations for Oil-immersed Transformers

为研究目前地下变电站变压器常用的分体冷却方式的实际散热效果,调研总结了应用于地下变电站的典型分体冷却系统布置方式,并根据ONAN方式的分体冷却系统的实际布置进行了模拟温升试验。地下变电站常用的分体冷却方式包括ODWF、OF/OF/AN和ONAN 3种。以1台110 kV/80MVA油浸式变压器为实验对象,采用变压器本体与散热器同水平面不同间距布置以及将散热器垂直提升5.75 m的实验方案,测量关键部位油温及绕组温度,对比不同模拟试验方案下的温升情况。研究表明,对于ONAN冷却方式的分体冷却系统,同水平面布置方式下,改变变压器本体与散热器间的水平距离对散热器的散热效果影响较小;将散热器垂直提升5.75 m布置会降低变压器和散热器间的油循环速度和散热器的实际散热功率,同时变压器绕组与变压器油间的热传递减缓,出现顶层油温不高但绕组温升已经很高的情况。文中的结论对实际工程中分体冷却装置的布置及变压器温升试验的改进具有参考价值。

In order to investigate the heat dissipation efficiency of the separated cooling installations used in under-ground substation transformers,the layout modes of the cooling systems are investigated.The ODWF,OF/OF/ANand ONAN cooling types are commonly employed in underground substation transformers.Scale model heat dissipa-tion experimental simulations are carried out for ONAN type separated cooling installations in accordance with itspractical layout mode.The experiments are carried out on an 80 MVA/110 k V oil-immersed transformer with ONANtype separated cooling installation.The temperature rise at key points in the cooling system and on the windings aremeasured under different operating conditions,such as changing the horizontal distance between the transformermainbody and the panel-type radiator,lifting the panel-type radiator vertically to 5.75 m,etc.The analysis andcomparison of the experimental results show that under horizontal layout mode,changing the separate distance be-tween the transformer mainbody and the panel-type radiator has little influence on the cooling efficiency.However,lifting the panel-type radiator to 5.75 m would slowdown the oil flow in the cooling system and thus reduce the cool-ing efficiency,leading to a phenomenon that the temperature rise in the oil at the transformer top is still low but thetemperature rise at the windings has risen much higher.The conclusion of this paper has reference value for the ar-rangement of separated cooling installations and the improvement of temperature rise test of transformer.