为了降低厂用电、提高机组效率，华能玉环电厂对凝结水泵进行了变频改造。提出了制约凝结水泵深度变频的因素是汽动给水泵密封水压力低和汽轮机低压旁路减温水压力约束，并给出解决方案。进行了凝结水泵深度变频后凝结水系统运行方式试验，包括不同条件下的除氧器上水主阀开度试验、变频控制凝结水母管压力的调节器参数整定、凝结水泵变频泵与工频泵切换试验、凝结水系统故障时凝结水泵变频调节试验等。经济效益分析表明：凝结水泵采取深度变频方式后，除氧器主阀完全开启，节流损失降到最低，凝结水泵电流和转速得到进一步下降，节能效果显著。

In order to reduce auxiliary power consumption and improve unit efficiency, frequency conversion transformation was implemented for the condensate pump in Huaneng Yuhuan power plant. The solution was suggested for the restrictive factors of depth frequency conversion of condensate pump which were the seal water of steam feed pump and the desuperheating water of low-pressure bypass in turbine. The operation tests were carried out for the condensate pump after depth frequency conversion, which included opening experiment of water-feeding main valve in deaerator, regulator parameter tuning of main pipe pressure in the condensate with frequency conversion control, switch test between variable frequency pump and general pump for condensate pump, frequency conversion adjustment test for condensate pump with condensate system fault occurred, and so on. The economic benefit analysis show that the depth frequency conversion for condensate pump can decrease the throttling loss to a minimum, and further reduce the condensate pump’s current and speed, when deaerator’s main valve is fully open, which can reach the effective energy saving.