摘要
建立了1000 MW超超临界凝汽式汽轮机最佳背压的计算模型,实时分析最佳背压随负荷、循环水流量和机组状态的变化关系。结果表明循泵功率变化和汽轮发电机功率变化均随循环水流量增加而增大。机组净出力随循环水流量先增大后减小,在一定循环水流量和背压下存在最大值。在高负荷下,降低背压带来的收益大于损耗,应尽量提高循环水流量,降低背压。低负荷下,采用一机一循泵模式合理;中高负荷下,采用两机三循泵模式合理;长期高负荷下,采用一机两循泵模式合理。在循环水入口温度维持基本不变时,汽轮机最佳背压随负荷增加而降低,最佳循环水流量随负荷增加而增大。
A model was developed to study the optimum back pressure of 1000 MW ultra-super critical condensing steam turbines. Thus, the effects of the unit load, conditions and the circulating water flow rate on the optimum Sack pressure were analyzed in real time. The results showed that the power output variations of the circulating water pump and the turbine-generator increased with the circulating water flow rate. The net power output of the unit increased and then decreased with increasing the circulating water flow rate. Thus, the net power output of the unit could be maxi- mized by adjusting the circulating water flow rate and the back pressure. At higher unit load, the gains by increasing the cireulating water flow rate and decreasing the back pressure were larger than the energy losses. At lower unit load, the mode of one unit and one circulating water pump was advisable. At higher unit load, the mode of two units and three circulating water pumps was advisable. At extremely high unit load for a long time, the mode of one unit and two circulating water pumps was advisable. At a given inlet temperature of the circulating water, the optimum back pressure decreased with the unit load while the optimum circulating water flow rate increased with the unit load.
出处
《能源工程》
2017年第4期69-74,共6页
Energy Engineering
关键词
凝汽式汽轮机
最佳背压
冷端损失
循泵运行模式
机组净出力
condensing steam turbine
optimum back pressure
energy loss in cold end
operational mode of circulat-ing water pump
net power output of the unit
