火电厂热力系统级的划分方法研究

Researsh on Stage Division Method of Thermal System in Coal-Fired Power Plant

火电厂热力系统状态方程与电厂热力系统结构一一对应,为越来越复杂的电厂热力系统的热经济性计算、分析与综合提供了新的基础和研究方法。热力系统状态方程的建立是以级为基础进行的,针对热力系统中级的划分方法进行了探讨,对从热力系统各管路出入热力系统的小汽水流量、热量及功划分到哪一级加热器级进行了定量分析,得出了这些小汽水流量、热量及功均可划分到与其相邻的任一级加热器级而不影响热经济性,而且不影响热力系统状态方程的填写规则,因此,为方便起见,加热器级的边界的选取应根据实际热力系统中测点的布置情况(或已知的参数)而定,而不一定以加热器的出口为界。

The thermo-eeonomy system state equation for coal- fired power plant responding to system＇s construction is a new research method to calculation, analyses and syntheses of the system thermo - economy, which is very useful for the increasing complex thermal power system. The construction of system state equation is based on the stage division. How to divide the thermal system into several single stages is discussed. It is quantitatively analysed which heater the little steam/water flows, heat and work flowing in/out the thermal system from every pipe lines should be included in and considered as a whole stage. Then the conclusion is drawn that each of these little steam/water flows, heat and work can be regarded as a stage with its any neighbor heaters, and don＇ t affect the thermal - economy and the construction regulations of the state equation. Therefore, it is convenient for thermal system calculation and analysis if the measured（ given parameters） points is chosen as the stage boundary, but not always the outlet of heater presented by normal division methods. That is the choice of stage boundary should be based on the actual arrangement of measured（ given parameters） points.