摘要
为提高并流蓄热式双膛石灰窑生产中石灰石的活性和降低能耗。以200 t/d的双膛石灰窑为研究对象,对采用自定义函数和自定义标量方程编译的局部非热平衡模型和石灰石化学反应模型添加前后的燃料、CO_2、O_2的质量分数分布及温度分布做了对比分析。结果表明:添加前后的燃料、O_2和CO_2质量分数分布趋势一致,添加前燃料和O_2的质量分数比添加后高,CO_2质量分数比添加后低;添加后煅烧带烟气温度分布为1 188～1 612 K,石灰石固体颗粒的温度为1 107～1 398 K,符合设计煅烧温度范围1 123～1 423 K;出口排烟和出料的模拟平均温度与同工况实测值相比,误差在15%以内;石灰窑煅烧窑体的预热带、煅烧带和冷却带的分布高度分别为3.5、6和4.5 m,与设计值基本吻合;添加后获得了设计工况下煅烧窑体中的碳酸钙累积分解率分布图,出窑时的分解率为0.961 5。
In order to improve the activity of limestone and reduce energy consumption in the production of dual-chamber lime kiln,with the study object of 200 t/d two-chamber lime kiln,the local non-thermal equilibrium model and the limestone chemical reaction model were compiled by using the self-defined scalar equation and the user defined functions.The numerical simulation results before and after the two models were added in the double-chamber lime kiln were compared and analyzed.It is concluded that: the mass fraction distributions of fuel,O_2 and CO_2 are consistent before and after the two models added,while the mass fractions of fuel and O_2 are higher,,and the mass fraction of CO_2 is lower in the case without the two models.After the two models added,the temperature range of flue gas temperature distribution is 1 188～1 612 K,and the temperature distribution interval of limestone solid particles is 1 107～1 398 K,meeting the design calcination temperature range of 1 123～1 423 K.Compared with the measured value,the error of simulated average temperature of outlet smoke exhaust and discharge is less than 15%.The distribution heights of preheating zone,calcinating zone and cooling zone of calcinations in lime kiln are 3.5,6 and 4.5 m,respectively,which are in good agreement with the design values.After the addition of models,the cumulative decomposition rate of calcium carbonate in the calcined kiln is obtained under the design condition,and the decomposition rate of the kiln is 0.961 5.
引文
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