上喷淋上进气喷淋塔换热性能数值研究

上喷淋上进气喷淋塔是降低燃煤电厂烟气含湿量的最合适方案。引入用户自定义函数来解决和揭示ST-UD内部的复杂过程,特别是利用已发表的实验数据和其他数值模拟结果对FLUENT模型进行了验证。在此基础上,进行了正交仿真试验,对操作参数的重要性进行了评价,分析了液滴直径、喷淋速度、喷淋水流量和喷淋水温度四个因素与塔效率和冷凝率两个评价指标之间的关系。通过极差分析,在有限的仿真数据内获得了不同评价指标的最优运行条件。喷淋液滴直径和流量是影响塔效率的主要因素,喷淋液滴直径、流量和温度是影响冷凝率的主要因素。通过趋势分析,探讨了不同操作因素对塔效率和冷凝速率的影响。本文的结论可为其它喷淋塔的性能优化提供参考。

Numerical Study on the Thermal Performance of a Spray Tower With Upward Spraying and Downward Gas Flow

The spraying tower with upward spraying and downward gas flowing(ST-UD)has emerged as the most appropriate solution to reduce the moisture content of flue gas in coal-fired power plants.The user defined functions are invited to solve and reveal the complicated processes within ST-UD.Particularly,the FLUENT model is validated with the published experimental data and other numerical simulation results.Then orthogonal simulation experiments were carried out to evaluate the importance of operating parameters and analyze the relationship between four factors(the droplet diameter,spraying velocity;spraying water flow rate and spraying temperature)and two evaluation indices(the tower effectiveness and condensation rate).Through range analysis,optimal operating conditions for different evaluation indices were obtained within the limited simulation scope.Further,diameter and flow rate of the spraying droplets are the main factors affecting the tower effectiveness,and diameter,flow rate and temperature of the spraying droplets are the main factors influencing the condensation rate.Through trend analysis,the effects of different operational factors on the tower effectiveness and condensation rate were discussed.The conclusion of this paper provides a reference for the performance optimization of other spraying towers.