燃煤产物组分的计算方法及提高非线性方程组求解收敛速度的措施

燃煤产物中各组分的数量级(从10~(-1)到~(-16))相差很大,直接运用最速下降法和牛顿法求解化学反应非线性方程组的收敛速度很慢,如果初值选取不当,还可能无法收敛。针对这个问题,本文对目标函数和变量的选取作了改进,显著提高了收敛速度和计算精度,使迭代次数从近百次减少到十次以下,大大缩短了计算所耗机时,而且对初值选取的精确性也无需提出严格的要求。

Calculatlono of Coal Fired Product Conposition and Measures For Speeding up Convergence in Solving Nonlinear Equations

Since the order of various components of coal fired product are different from each other to a great extent, the convergent speed by using the steepest descent and Newton's method directly will be very slow. It is a computer time consuming job and divergent if the initial values of product composition is not rationally selected. For solving this problem, this paper improves the selection of variables aand objective function. It enhances the convergent speed and calculation accuracy obviously and decreases the iteration from about hundred times to less than ten times, which shortens the computer time consumption to a great extent. In addition, the initial value selection with accuracy is no more required.