氧化铝蒸发工艺末效乏汽的余热回收利用

Waste Heat Recovery and Utilization of the Last Effect Exhaust Steam in Alumina Evaporation Process

某公司氧化铝生产工艺采用大气冷凝器吸收乏汽,乏汽的热量和凝结水均得不到充分利用,同时采用冷却塔降温需要消耗大量循环水,循环泵和冷却塔风机电耗高。为了回收乏汽余热,通过方案比较,选用汽冷型第一类吸收式溴化锂热泵,改造蒸发器循环水系统,直接回收蒸发工艺末效蒸发器的乏汽潜热,使其成为供暖热源。乏汽余热回收每年可产生效益约1 130万元,且替代锅炉燃煤供热,大大减少了大气污染排放。

The alumina production process of a company used atmospheric condenser to absorb exhaust steam,and the heat of exhaust steam and condensate water were not fully utilized.Furthermore,the cooling tower needed to consume a large amount of circulating water,and the power consumption of circulating pump and cooling tower fan was high.In order to recover the waste heat of exhaust steam,through the comparison of schemes,the first type of vapor-cooled absorption lithium bromide heat pump was selected,and the circulating water system of evaporator was reformed to directly recover the latent heat of exhaust steam in the final evaporator of evaporation process,so as to make it become a heating source.Exhaust waste heat recovery can produce about 11.3 million yuan per year,and replace the boiler coal-fired heating,greatly reducing air pollution emissions.