户内主变压器室通风散热优化设计研究

Optimization of ventilation and heat dissipation for main transformer room in the indoor substation

建立某110 kV户内主变压器室通风散热三维模型,利用计算流体力学方法研究了变压器室自然通风临界温度,机械排风速率,进、出风口位置及大小对其散热特性的影响,并分析了原始方案与优化后方案中变压器室内的流动特性。结果表明:原始方案中变压器自然通风临界温度约为22℃,且随着室外环境温度升高,自然通风时室内变压器靠近底部区域易出现热量堆积,造成变压器散热量无法及时排出,进而对变压器的安全、稳定运行造成危害。在自然通风临界温度为22℃时,所需最小机械排风速率为2.56 m·s^(-1)。增大进、出风口面积以及降低出风口位置均有利于增强变压器室内散热效果,使变压器室排风温度显著降低。将两个风机位置调低可使出风口平均温度降低1~2℃。与原始方案(风量2.56 kg·s^(-1))相比,优化后方案(风量降低至1.50~2.00 kg·s^(-1))可满足该变压器室通风散热需求,从而达到优化风量、降低噪声的目的。

Three-dimensional ventilation and heat dissipation model of a 110 kV main transformer room in the indoor substation was established to investigate the effects of critical natural ventilation temperature,mechanical exhaust rate,and size and position of the fans on its heat disspation performance.Meanwhile,comparison of the flow characteristics in the transformer room between original design and optimized design was made.Results show that for the original design,the critical temperature of natural ventilation is 22℃.As the outdoor temperature rises,indoor transformer is prone to the accumulation of heat near the bottom area during natural ventilation,endangering its safe and stable operation.At the natural ventilation critical temperature of 22℃,the minimum mechanical exhaust rate is required at 2.56 m·s^(-1).Increasing the inlet/outlet area of air and reducing the height of air outlet are beneficial to the enhancement of heat dissipation in the transformer room,and the exhaust temperature decreases significantly at the same time.Additionally,when the location of axial fans is lowered,average temperature at the exhaust outlet reduces by about 1~2℃.Comparing with the original design with air volume of 2.56 kg·s^(-1),the optimized design with air volume of about 1.50~2.00 kg·s^(-1)can meet the requirements of ventilation and heat dissipation in the transformer room,thereby achieving the purposes of air volume optimization and noise reduction.