2×1000MW机组循环水系统一机双塔改造热耗变化研究

Heat Consumption Variation of 2×1 000 MW Unit Circulating Water System One-Unit Two-Tower Modification

针对某电厂2×1000MW机组单机运行工况较长,夏季机组背压高于设计值的现状,拟通过对原单元制供水系统进行一机双塔改造,降低单机运行时凝汽器循环水进水温度。提出了一种一机双塔改造热耗变化分析方法:在利用PIPENET软件对改造后一机双塔水力分析的基础上,分别对冷却塔、凝汽器进行热力分析,确定凝汽器背压变化情况;进而利用机组"背压-热耗曲线",得出改造后机组热耗降低值。

Considering that the single operation condition of 2×1 000 MW units in a power plant is long and the unit back pressure is higher than the designed value in summer, it is proposed to transform the original unit water supply system with one unit and two towers to reduce the inlet water temperature of circulating water in the condenser during the single operation. This paper proposes a method to analyze the change of heat consumption in the reconstruction of one unit and two towers: based on the hydraulic analysis of the two towers after the reconstruction with PIPENET software, the thermal analysis of the cooling tower and condenser is carried out respectively to determine the change of the back pressure of the condenser. Then, by using the "back pressure heat consumption curve" of the unit, the reduction value of heat consumption of the unit is obtained.