T-T吸收剂脱硫模型的改进及与双流体模型的耦合

IMPROVED SULFUR CAPTURE MODEL OF T-T SORBENT AND ITS COUPLING WITH EULERIAN TWO-FLUID MODEL

原有T-T吸收剂固硫模型以时间作为反应状态参数,无法用于欧拉法脱硫模拟。为此,基于钙转化率的概念,对已有的T-T吸收剂脱硫模型进行了改进。改进的模型形式简单,反应速率与钙转化率的平方呈双线性分布,模型中快慢反应的转折点和反应终止点均随温度升高而增大,表征了反应活性的提高。进一步推导了吸收剂钙转化率的输运方程并对两相质量守恒方程和SO_2组分方程进行了修改,将脱硫模型与两相流模型进行了耦合,为循环流化床脱硫数值模拟打下了基础。

The existing sulfur capture model of T-T sorbent cannot be used in the simulation of desulfurization with Eulerian two-fluid model for it is a function of time. Based on the concept of Calcium conversion rate, the sulfur capture model has been improved for two-fluid model simulation. The improved model shows a linear relationship between the reaction rate and the square of conversion rate in different ranges. Both the reaction stop point and the critical point which represents the transition from fast to slow reaction increase with the increasing of temperature. As a result, the differential function of Calcium conversion rate has been conducted and the related functions in the two-fluid model have been modified for the incorporation of the sulfur capture model, which serve as the theoretical basis for simulating flue gas desulphurization processes.