直接空冷机组乏汽回收供热空冷防冻问题探究

Research on Antifreeze Problem of Direct Air-cooled Unit Exhaust Steam Recovery and Heat Supply

某热电有限公司两台直接空冷机组配有溴化锂吸收式热泵,利用乏汽供热,即冬季供热期通过降低真空度,提高低压缸排汽温度,加热一次热网回水,减少冷源损失,大大提高机组经济性。但直接空冷机组空冷凝汽器冻结是常见的现象,乏汽回收后,空冷岛进汽量进一步减少,空冷凝汽器防冻问题更加严峻。经过多年的探索、技术改造,有效避免了空冷凝汽器冻结事故的发生。

Two direct air-cooled units of a thermal power company are equipped with lithium bromide absorption heat pumps.The exhaust steam temperature of the low pressure cylinder is increased by reducing the vacuum during the heating period in winter.The return water of the primary heating network is heated to reduce the loss of cold source and greatly improve the economy of the unit.However,freezing of the air condenser of a direct air cooling unit is a common phenomenon.After the exhaust steam is recovered,the amount of steam entering the air-cooling island is further reduced,and the anti-freezing problem of the air condenser is more severe.After years of exploration and technical transformation,the freezing accident of the air condenser has been effectively avoided.