加热器抽汽压损对机组煤耗影响的通用计算模型

以小扰动理论为基础,根据火电机组热力系统汽水分布通用矩阵方程、比内功方程、循环吸热量方程及发电标准煤耗率的计算公式,导出了加热器抽汽压损对机组煤耗影响的通用计算模型。该模型全面考虑了热力系统的结构特点、辅助汽水、外热量等因素,较之以往模型更为完善、直观,通用性强,适于程序化。计算实例表明:该模型能准确而快速地评价各级加热器抽汽压损变化对煤耗的影响,对热力系统的设计、运行和检修具有十分重要的意义。

General models for calculating influence of steam extraction pressure loss on coal consumption of units

Based on the small disturbance theory,the steam-water distribution general matrix equation of the thermal system of fossil-fired units,the specific internal work equation,the cycle heat absorption equation,and the calculation formula of standard coal consumption rate for power generation were used to educe the general model for calculating the influence of steam extraction pressure loss of the heater on coal consumption of units.The model fully considers the structural characteristics of the thermodynamic system as well as the steam-water auxiliary system,and is more visual,universal,and suitable for programming than traditional ones.Calculation example proves that the model can accurately and quickly assess the influence of steam extraction pressure loss on coal consumption of units.