复杂反应体系的化学平衡分析

Chemical Equilibrium Analysis of Complex Reaction Systems

本文提出了一种新的通用化学平衡计算方法.该方法以反应程度和组分摩尔数同为迭代变量,用松弛法估计初值,Newton-Raphson法加速收敛,具有良好的收敛稳定性.同时用新算法分析了甲烷蒸汽转化中的结焦和Ti(C.N)的化学气相沉积,并对NH_3-CO_2-SO_2-H_2S-H_2O-CH_4-C_2H_6体系进行了热力学计算.所有考证的实例从零初值都得到了正确的结果.

A new generalized algorithm for chemical equilibrium calculation is presented. This method can effectively determine whether a pure solid phase exists and accurately evaluate the compositions of trace species with the extents of reaction and moles of components as the iterative variables. The efforts required for the inverse of Jacobian matrix are equivalent to the method where only the extents of reaction are iterative variables by a linear transformation. This approach begins with estimating the initial value with relaxation method and convergence can be accelerated by Newton-Raphson method. The singularity of Jacobian matrix can be overcome with the help ot damped Newton-Raphson method. The approach has the same robustness as Marquardt method used by Xiao et al. (1989). All the examples tested converge to the correct solutions from zero iterative variables. The carbonation of methane steam shift system and the chemical vapor deposition of Ti(C, N) are analy-sized. The computed results of NH3-CO2-SO2-H2S-CH4-C2H6 system are also presented.