某大型火电机组的高压加热器（高加）正常疏水管路布置不合理，多次出现疏水管路振动，危及设备安全。根据高加正常疏水管路的实际布置位置进行了改造，机组启动初期利用静压差和凝汽器的真空排除正常疏水管路的积水，彻底消除了管道振动，杜绝因振动造成的设备损坏事故。新建机组可以按照无低点、无U型管的设计方案进行优化设计，可以从根本上消除因级间差压小造成的管道振动。

The arrangement of normal drain pipeline in high pressure (HP) heater in a large thermal power unit is unreasonable, which results the vibration of drain pipeline occurred repeatedly and endangers the safety of equipment. Some retrofits are carried out for the normal drain pipeline according to its arrangement in HP heater, such as excluding the water in normal drain pipe by using static pressure difference and condenser vacuum at the initial period of units’ start-up, which could completely eliminate the pipeline vibration, as well as prevent the equipment damage accident caused by vibration. New units could be optimized designed without low-point and U-tube, which could radically eliminate the pipeline vibration caused by small interstage differential pressure.