用于欧拉数值模拟的改进T-T吸收剂固硫模型

为了实现循环流化床反应器中的中温多相流动脱硫反应过程的数值模拟,将T-T吸收剂的固硫模型引入到欧拉双流体模型中。但表征T-T吸收剂固硫特性的钙转化率是时间的函数,不能作为状态参数使用。为此,通过数据转换,将钙转化率对时间的导数,即吸收剂的反应速率与钙转化率建立了相互关系。同时发现,反应速率与钙转化率的平方之间具有分段线性的特征,由此获得了改进的T-T吸收剂固硫模型。进一步推导出钙转化率的输运方程,从而封闭了欧拉双流体反应方程组,为模拟烟气脱硫反应过程提供了理论基础。

Improved sulphur capture model of T-T sorbent for eulerian simulation

In order to realize simulations of multiphase flow and desulphurization reaction processes at medium temperature in CFB reactor, a sulphur capture model of T-T sorbent has been introduced in the Eulerian approach. The Calcium conversion rate that represented the sulphur capture behavior of the sorbent was a function of time and could not be used as a state parameter. For this reason, a new relationship between the derivative of Calcium conversion rate with respect to time, namely the reaction rate of T-T sorbent, and Calcium conversion rate has been set up according to experimental data. It has been found that the reaction rate is proportional to the square of Calcium conversion rate in different ranges. As a result, an improved sulphur capture model of T-T sorbent has been obtained and a differential equation for Calcium conversion rate derived. Thus, the conservation equation set for multiphase reaction flows in Eulerian frame was closed and served as the theoretical basis for simulating flue gas desulphurization processes.