大型锅炉长期动态特性研究中的烟气计算模型

Flue-gas Calculation Model Used in the Study of Long-term Dynamic Characteristics of a Large-sized Boiler

为了简便、准确、快速地解决大容量锅炉汽轮机组长期动态特性研究中的烟气放热计算问题 ,本文针对现有仿真用烟气放热模型的主要不足 ,由大容量锅炉热力计算的杜卜斯基 -卜劳赫公式推导出新的仿真与动态特性分析用炉膛烟气放热模型 ;并通过简要的分析、简化和推导 ,得出了动态过程中各种锅炉换热面烟气出口温度和放热量计算方法 ,这些烟气计算模型能够较为准确、简单地反映动态过程中高温烟气在大容量锅炉的炉膛和各烟道换热面的烟温及放热量的变化规律 ,应用十分方便。最后将本文的烟气计算模型应用于某 6 0 0MW超临界机组的动态特性仿真 ,仿真结果合理。

The study of long term dynamic characteristics of a large sized turbogenerator set requires a simplified, accurate and rapid calculation of flue gas heat release rate. To eliminate the main deficiency of currently used flue gas heat release simulation models the authors have deduced from Dybosky Broch formula of large sized boiler thermodynamic calculation a new flue gas heat release model for the simulation and analysis of dynamic characteristics. Moreover, through a concise analysis, simplification and deduction obtained was a method for calculating flue gas outlet temperatures and heat release rates in a dynamic process for various boiler heat exchange surfaces. The recommended easy to use flue gas calculation model offers a relatively accurate and simple expression of the variation mechanism of flue gas temperature and heat release rate of high temperature gases in the furnace and various gas pass heat exchange surfaces of a large sized boiler during a dynamic process. The flue gas calculation model has been used to simulate the dynamic characteristics of a 600MW supercritical power generation unit with rational and accurate simulation results being obtained.