凝结水泵变速运行节能潜力分析

Analysis on Energy Saving Potential for Variable-speed Operation of Condensate Pumps

提出凝结水泵变速运行"平衡点"的概念并阐述了其实用意义.建立了平衡点的计算模型,并通过理论推导得出其计算公式.在此基本上,提出并论述了提高凝结水泵变速运行节能效果的3个途径,即将凝结水泵出口压力维持在最低允许值、提高平衡点负荷、采用可变的凝结水泵出口压力最低允许值.对采用减少叶轮级数的方法无益于提升变速凝结水泵节能效果的原因进行了分析.最后,通过某电厂300 MW机组凝结水泵的计算实例表明:应用平衡点计算式得到的计算结果与实际值基本一致.

A new concept of ＂balance point＂ for variable-speed operation of condensate pump was proposed and its practical meaning was also described. A model for calculation of the balance point was established and the calculation formulas were obtained through theoretical deduction. On this basis, three measures were recommended to improve the energy-saving effect of variable-speed operation of condensate pumps. maintaining the outlet pressure of condensate pump at lowest permitted value, increasing load at balance point and adoption of variable lowest permitted value of outlet pressure for the condensate pump. And the reason why reducing impeller stages of the condensate pump is of no use for energy-saving was analyzed. Finally, the case calculation of the condensate pump in a 300MW unit shows that the calculation results obtained from the balance point formulas are basically consistent with the practical values.