220 kV重负荷变压器强油风冷系统现场改造分析

On-Site Reformation for Cooling System of 220 kV Heavy Load Forced-Oil Circulation Air-Cooled Transformer

针对乌兰察布电业局220kV重负荷强油风冷变压器结构复杂、设备陈旧、散热效率低、缺陷及隐患多等问题,对冷却系统建模并进行理论计算分析,结合现场实际情况,进行片式自冷与自冷风冷方式相结合的冷却系统改造,确定片式散热器布置形式及数量,制订220kV重负荷变压器现场冷却系统改造施工方案及关键工序的质量管控措施。通过对新城湾3号主变压器冷却系统的现场改造,有效降低油面温升约6℃,同时可增带负荷约4万kW。现场改造可缩短工期约46d,减少运行电量损失约278万kWh,延长了主变压器运行寿命,改造效果较好。

In view of the issues exist in 220 kV transformer of Ulanqab Electric Power Bureau,the cooling system is modeled and theoretically analyzed combined with the actual situation on the site.The quality control of key processes such as transformer tank opening,welding tubing,transformer body overhaul and reinforced insulation is expounded,and the existing dangers are analyzed in detail.Put forward the effective pre-control measures such as rain protection,sand control,and foreign matter prevention.Through the on-site reconstruction of the No.3 main transformer cooling system in Xinchengwan,the oil surface temperature rise is effectively reduced by about 6℃,and the load can be increased by about 40 000 kW.At the same time,the on-site renovation will shorten the construction period by about 46 days,saving the running power loss of 2.78 million kWh,prolonging the main transformer operating life,and the transformation effect is better.