解决热力系统通用计算软件中的两个问题

Solving Two Problems on Universal All-Graphic Software for Calcu lation of Thermal System

文献[1]中介绍的软件能自动生成热平衡方程组fi(x1,x2,x3,x4,x5,x6,x7,x8)=0(i=1～8)。为了避免用matlab求解带符号的方程组,增强软件的独立性,本文通过求多项式的值来实现从上述方程组中提取矩阵方程A.x=τ,这样就可以通过调用矩阵求解模块解出加热器的各级抽汽系数。另外,介绍了在面式加热器热平衡方程的基础上增加一个修正项来构造疏水泵式加热器的热平衡方程。从这个修正后热平衡方程组中提取出矩阵方程,观察该矩阵形式,得出如下结论:当热力系统中的某一级加热器带有疏水泵时,矩阵A不再是标准的下三角阵,而是在主对角线旁边多出一个非零项,这个非零项正是由构造热平衡方程时的修正项造成的。

The software introduced in reference ca n automatically create the thermal balance equations fi(x1, x2, x3, x 4, x5, x6, x7, x8)=0(i=1～8) . To avoid solving symbolic equations by matlab to improve the indepen-dence of the software, this paper presents a method of extracting the matrix equation A.x=τ from the abo ve referred equations by solving the value of polynomial, thus we can get the ex haust coefficient of each reheater by the matrix solving model. In addition, thi s paper introduces a method of creating the equation of the reheater with draini ng pump by adding a compensation factor to the normal thermal balance equation. Observing the matrix extracted from the modified equations, we can draw the conc lusion as follow: when a reheater in the thermal system has the draining pump, t he Matrix A will not be in the shape of a exact down-triangle, but there is a n one zero item along the main diagonal, which is just caused by the compensation factor of the modified thermal equation.