凝结水节流变负荷能力静态建模与分析

Static Modelling and Analysis on Load Change Capability of Condensate Throttling

基于汽水分布方程,计算得到凝结水节流后机组各级抽汽质量流量的变化,并在此基础上建立了凝结水质量流量对汽轮机输出功率影响特性的2个边界模型,确定了凝结水节流方案的可达负荷;在分析除氧器内蓄水温度变化的基础上,确定了当前蓄水量下凝结水节流的可持续时间,并以某600 MW机组为例进行验证.结果表明:凝结水节流方案可使机组的变负荷速率提升一倍以上,且机组负荷越高,凝结水节流在相同的节流倍率条件下具备的可调能力越强.

Using steam-water distribution equation, the variations of extraction flow caused by condensate throttling were calculated for each stage of unit, based on which two boundary models were set up for the relationship between turbine power output and condensate water flow, so as to determine the range of load change by condensate throttling. On the basis of analyzing the water temperature change in deaerator, the maintain time of condensate throttling under present water storage was obtained, which was subsequently verified by a 600 MW unit. Results show that condensate throttling would double the rate of load change in power plants~ moreover, the load change capability would be stronger when the unit load is higher, in the case of same throttling rate.