针对1 000 MW机组热力系统回热抽汽过热度偏高的问题,提出采用外置式蒸汽冷却器系统，比较了变负荷条件下1 000 MW机组常规系统和外置式蒸汽冷却器系统的〖HT5”，7〗火〖KG-*3〗用〖HT5”〗损系数，分析了外置式蒸汽冷却器系统节能效果。结果表明：相比常规系统外置式蒸汽冷却器系统的发电效率提高0.19%，发电煤耗降低0.54 g/（kW·h）；外置式蒸汽冷却器系统中锅炉〖HT5”，7〗火〖KG-*3〗用〖HT5”〗损系数和回热加热器〖HT5”，7〗火〖KG-*3〗用〖HT5”〗损系数均低于常规系统，在两种热力系统中，回热加热器的〖HT5”，7〗火〖KG-*3〗用〖HT5”〗损系数随着负荷的降低而降低，锅炉〖HT5”，7〗火〖KG-*3〗用〖HT5”〗损系数随着负荷的降低而增大。

The superheat degree of extracted steam in the regenerative system of a 1 000 MW unit is too high.In order to solve this problem，a regenerative system with an outer steam cooler is proposed and presented in this paper.Comparative study on exergy destruction coefficient of the conventional reference system and the outer steam cooler system under variable load operation conditions are conducted to investigate the energy saving effect with the outer steam cooler system.The results show that,compared with the reference system,the power generation efficiency is improved by 0.19%,and the coal consumption rate of the outer steam cooler is reduced by 0.54 g/kWh.The exergy destruction coefficients of the boiler and the regenerative heaters in the outer steam cooler system are lower than those of the reference system under all operation conditions.Both in the two systems,the exergy destruction coefficient of the regenerative heater is reduced as the load decreases.However,the exergy destruction coefficient of the boiler is increased as the load decreases.

TM621

国家自然科学基金(51436006)；江苏省自然科学基金面上项目（18KJD480003）