二次再热机组的热耗变换系数和汽耗变换系数

热耗变换系数和汽耗变换系数是反映抽汽品质的重要参数，便于分析定功率下机组的特点。文中给出了二次再热机组热力系统的矩阵热平衡方程，对其填写规则进行了阐述。提出了二次再热机组热力系统的热耗变换系数、汽耗变换系数、抽汽效率和等效热降的数学表达式。对二次再热机组抽汽间相互作用的特性进行了分析。以某二次再热机组为例，对以上4个参数进行了计算，计算结果不仅证明了hM=hi/ξi和dM=ki/Hi0，而且也说明主循环效率和汽耗率只和热力系统的节点参数有关。通过对计算结果进行分析，发现热耗变换系数随抽汽级数由高压级到低压级逐渐减小。

Heat Rate Transformation Coefficient and Steam Rate Transformation Coefficient of Thermodynamic System for Power Unit With Double Reheat

Both the heat rate transformation coefficient and steam rate transformation coefficient are two of the principle parameters to reflect the character of extraction steam,making it easy to analyze the performance of a power unit under conditions of constant power output. The thermal balance matrix equation for thermodynamic system of a power unit with double reheat was derived, in which the rules to fill were represented. Based on this structural matrix, the mathematical equations for heat rate transformation coefficient and steam rate transformation coefficient were also derived by strict deduction. The interactional relations influenced by the change of extraction steam were also analyzed. The results of the calculations of the power unit with double reheat prove that hM=hi/ξi and dM=ki/Hi0, and indicate that both main cycle efficiency and steam consumption only rely on the parameters of thermodynamic system. The analysis shows that heat rate transformation coefficient decreases along with extraction steam pressure decreases.