六回路循环流化床甲烷化过程数值模拟及优化

Numerical simulation and optimization of methanation process in six-loop circulating fluidized bed

为深入了解循环流化床甲烷化反应特性并对操作参数进行优化,采用计算颗粒流体力学(CPFD)方法对六回路循环流化床甲烷化过程进行了数值模拟,基于单因素分析,通过响应曲面法,建立了二次回归模型,分析了操作参数:入口气速、入口温度和n(H_(2))/n(CO)对CH_(4)产率的影响,从而确定了最优操作参数。结果表明:单因素对CH_(4)影响权重顺序为:n(H_(2))/n(CO)>入口温度>入口气速。响应面优化得到最优操作参数为入口气速6.94 m/s,入口温度556.8 K,n(H_(2))/n(CO)为3.3,在最优操作参数下CH_(4)产率模拟值为0.5696,与回归模型优化值0.5880接近,相对误差为3.13%。

In order to gain insight into the characteristics of circulating fluidized bed methanation reactions and optimize the operating parameters,the numerical simulation of the six-loop circulating fluidized bed methanation process was carried out by computational particle fluid dynamics(CPFD)method.Based on the single factor analysis and response surface method,a quadratic regression model was established.The effects of operating parameters:inlet gas velocity,inlet temperature,n(H_(2))/n(CO)on CH_(4)yield were analyzed and the optimal operating parameters were determined.The results show that the order of weight of single factor on CH_(4)yield is:n(H_(2))/n(CO)>inlet temperature>inlet gas velocity.The optimum operating parameters obtained by response surface optimization are inlet gas velocity of 6.94 m/s,inlet temperature of 556.8 K and n(H_(2))/n(CO)of 3.3.Under the optimal operating parameters,the simulated value of CH_(4)yield is 0.5696,which is close to the optimization value of regression model of 0.5880,and the relative error is 3.13%.