凝汽机组高背压供热改造后的性能指标与调峰能力分析

介绍了135 MW、300 MW等级凝汽机组高背压供热改造技术，由机组改后的性能试验，得到机组高背压运行的性能指标，高背压纯凝工况下的热耗率为3 690~3 740 kJ/（kW·h），高背压抽汽工况下的热耗率在3 690~4 060 kJ/（kW·h）之间。并分析了改造技术、冷端设计参数与运行参数对机组性能指标的影响，同样135 MW等级机组，满负荷工况下，循环水流量差3 500 t/h，凝汽器背压差15 kPa，机组额定工况下的发电功率差26.7 MW。由机组供热期调峰能力试验，确定机组高背压运行的调峰区间和调峰适应性，300 MW机组的调峰能力为65 MW，为改造前额定容量的22%；而135 MW等级机组的调峰能力为35~60 MW，为改造前额定容量的26%~44%。并分析了造成机组调峰区间变窄、调峰适应性降低的原因。

Analysis of Performance Indicators and Peak Regulation Capacity of Condensing Unit After High Back Pressure Retrofit for Heating

The article explains the heating supply technology retrofit for 135 MW and 300 MW grade units at high back pressure condition. The performance indicators of high back pressure operational conditions are obtained through performance test after retrofit. At high back pressure operational mode, the heat consumption rate of pure condensing condition is among 3690~3740 kJ/(kW·h), the heat consumption rate of extraction steam condition is among 3690~4060 kJ/(kW·h). The effect of retrofit technology, cold end design parameters and operational parameters on performance indicators has been analyzed. For the same 135 MW grade unit, under full load condition, the difference of circulating water being 3500 t/h, the difference of condenser pressure is 15 kPa. The difference of generator power at full condition is 26.7 MW. By peak regulation capacity test during heat supply period, the peak regulation range and adaptation with high back pressure operational mode have been determined. The power load regulation capacity of 300 MW unit is 65 MW, being 22% of rated capacity before retrofit. The power load regulation capacity of 135 MW unit is 35~60 MW, being 26%~44% of rated capacity before retrofit. The reason that resulting peak regulation range narrow and peak regulation decrease also have been analyzed.