针对某电厂600 MW热电联产机组,采用喷水置换配合冷再抽汽方案来提高其供热能力,运用Ebsilon软件搭建了机组机炉一体化模型,在考虑锅炉和汽机安全约束的条件下,对喷水置换配合冷再抽汽方案进行了最大供热抽汽量与喷水量的研究；分析了不同再热器喷水量对高压缸末级级组压差、再热器进出口温度等关键参数及煤耗率等关键指标的影响。结果表明:随着喷水量的增加,机组的供热能力得到提高,高压缸末级级组压差增幅减小,再热器进口蒸汽温度下降,发电标准煤耗率上升,供热标准煤耗率上升。在VWO工况下机组可达到最大供热抽汽量180 t/h,喷水量为85.351 t/h,对应高再与低再喷水比例为0.379,发电标准煤耗率为0.280 kg/(kW·h),供热标准煤耗率为38.172 kg/GJ。

A scheme of water spraying replacement to cold reheat steam extraction was adopted to improve the heating capacity for 600MW cogeneration unit of a power plant.The boiler-turbine integration model of the unit was constructed by using the Ebsilon software, and the maximum amounts of heat extraction and water spraying were studied in the scheme under the conditions of boiler and turbine safety constraints.The effects of different reheater water spraying quantities on key parameters such as differential pressure of high-pressure cylinder final stage group, reheater inlet and outlet temperatures, and key indicators such as coal consumption rate were analysed.The results show that with the increase of water spraying quantity, the heating capacity of the unit is improved, the increase of differential pressure of high-pressure cylinder final stage group is reduced, the inlet steam temperature of reheater is decreased, the standard coal consumption rate of power generation is increased, and the standard coal consumption rate of heating supply is increased.Under the VWO operating condition the unit can achieve the maximum heating steam extraction capacity of 180 t/h, the water spraying capacity of 85.351 t/h, corresponding high temperature reheater and low temperature reheater water spraying ratio of 0.379,the standard coal consumption rate for power generation of 0.280 kg/(kW-h), and the standard coal consumption rate for heat supply of 38.172 kg/GJ.