加热器端差对机组热经济性影响的定量分析方法

A Method for the Quantitative Analysis of the Impact of Terminal Temperature Differences of Heaters on Thermal Effectiveness of Power Generating Units

建立了定流量下加热器端差对机组热经济性影响的数学模型。该模型针对加热器的不同类型进行了讨论,应用时不再需要单独计算端差变化对锅炉吸热量的影响,并全面考虑了热力系统的结构特点及辅助汽水系统,从整体上定量分析加热器端差对机组热经济性的影响,为火电机组节能降耗以及热力系统定量分析提供了理论依据。对某600MW机组进行了算例分析,表明端差越大,机组的热经济性越低;端差越小,机组的热经济性越高。

A mathematical model has been established to analyze the impact of terminal temperature differences of heaters under a given flow rate on the thermal effectiveness of power generating units.By using the model,different types of heaters are discussed and it is no longer necessary to independently calculate the influence of the change in terminal temperature differences on the heat absorption quantity of boilers.By taking into account in a comprehensive way the structural features of a thermal system and also an auxiliary steam-water system,an integral and quantitative analysis was performed of the impact of the terminal temperature differences of heaters on thermal effectiveness of power generating units.The foregoing can well provide a theoretical basis for achieving energy saving,reducing coal consumption of thermal power plants as well as performing a quantitative analysis of the thermal systems.The analysis of a calculation example for a 600 MW power generating unit shows that the greater the terminal differences,the lower the thermal effectiveness of the power plant and the smaller the terminal differences,the higher the thermal effectiveness of the plant.