顺流吸湿溶液喷淋塔理论与数值模拟研究

Theoretical and numerical simulation on parallel-flow dehumidifying solution spray absorber

开式循环吸收式热泵技术能有效回收燃煤锅炉脱硫后饱和湿烟气中的潜热,同时降低烟气相对湿度,有效消除湿烟羽。溶液喷淋吸收塔是该技术的重要组成部分,通过对顺流溶液喷淋吸收塔的理论研究,建立吸收塔一维热质交换数学模型,采用MATLAB软件对模型进行求解,以预测吸收塔的吸收效果;利用该模型分析了液气比、液滴粒径、吸收塔高、烟气流速、液滴初速、吸湿液质量分数、温度等关键因素对吸收塔吸收效果的影响。结果表明:在给定范围内液气比、吸湿液温度对吸收器理想全热交换效率影响显著,质量分数影响相对较小;液滴粒径、吸收塔高对吸收器结构效率影响显著,而烟气流速、液滴初速的影响相对较微弱。该结论可用于指导燃煤电厂顺流溶液喷淋吸收塔的设计。

Open-cycle absorption heat pump technology can effectively recover the latent heat of saturated wet flue gas after desulfurization in coal-fired boilers.At the same time,it can reduce the relative humidity of flue gas and effectively eliminate wet plume.Dehumidifying solution spray absorber is an important part of the technology.A one-dimensional heat and mass transfer mathematical model of the parallel-flow dehumidifying solution spray absorber was established by theoretical study.The model is solved by MATLAB software to predict the absorption effect of spray absorber and guide the design of spray absorber.The effects of key factors such as liquid-gas ratio,droplet size,spray absorber height,flue gas velocity,initial droplet velocity,mass fraction of absorbent liquid and temperature on the absorption efficiency of spray absorber were analyzed by using the model.The results show that,the ratio of liquid to gas,and the temperature of absorbent liquid have significant effects on the ideal total heat exchange efficiency of the absorber,while the absorbent liquid mass fraction has relatively weak effect.The droplet size and spray tower height have significant effects on the absorber’s structure efficiency.The influence of the flue gas velocity and droplet initial velocity is relatively weak.The results can be used to guide the design of downstream solution absorption tower in coal-fired power plants.