摘要
开发了一个考虑惰性物含量影响的颗粒石灰石固硫模型，其创新之处有：（１）突出了石灰石化学组成对固硫过程的影响，将惰性物含量作为模型的一个参数；（２）采用不稳态的质量方程来模拟ＳＯ２气体向氧化钙颗粒内部的扩散，消除了难稳态假设带来的误差；（３）考虑了在固硫过程中氧化钙颗粒孔隙结构变化对气体扩散的影响。通过对模型中偏微分方程组的离散化处理，开发了一个有界Ｗｅｇｓｔｅｉｎ数值求解方法，具有收敛快，计算精度高等优点。计算结果表明，惰性物质的存在有助于减缓孔堵的发生，从而提高了钙的利用率；但如果惰性物含量太高，则石灰石固硫的速度和容量太小。文中首次提出了最佳石灰石惰性物合量的概念和筛选流化床固硫用石灰石的标准，具有较强的实用价值。
A model of sulphur retention by limestone in presence of inerts has been developed,which blaze the following new trails:(1)the effect of sorbent chemical composition on the process of SOZ capture is stressed and the amount of inerts in limstone is taken as an palameter:(2)mass equations in transient nature for modelling SOZ diffusion into a lime particle is established and errors caused by traditional Pseudosteady assumption are eliminated;(3)the influence on gas difffusion in the process exerted by pore structure variations of the particle is taken into consideration. By scattering a series of partial differential equations in the model, a numerical method called limited Wegstein with the merits of quick convergence and high precision has been achieved.The calculation results have revealed that the presence of inerts benefits slowing down the pore blocking process, so the calcine utilization in calcine is improved, however,if the fraction of inerts in calcine is too large the overall rate and capacity of calium sulphation may be very low.The concept of the optimal amount of inerts in calcium for sulphation and the criteria for selecting limestone used as desulphurizer in fluidized beds have been proposed here which will find practical applications.
出处
《热力发电》
北大核心
1996年第5期3-10,共8页
Thermal Power Generation
