1000MW机组抽汽压损对损影响的定量分析

Quantitative Analysis about the Influence of Extraction Steam Pressure Loss to Exergy Loss on 1000MW Unit

抽汽压损是一种不明显的热力损失,使蒸汽的作功能力下降、热经济性降低。假定抽汽口的压力不变,加热器端差不变,分析抽汽压损变化对热力系统的影响。根据抽汽压损的理论分析和热力系统汽水分布方程建立抽汽压损对回热系统抽汽系数影响的数学模型,并结合平衡原理和小扰动理论建立抽汽压损对损分布的影响的数学模型。以某电厂N 1 000-25/600/600机组热力系统为例,在TRL工况下,定量计算热力系统损变化情况。根据定量计算结果定性分析了抽汽压损对热力系统的影响。

Extraction pressure loss is difficult, to find in heat loss, makes power function of steam down and reduces heat economy. Assuming the pressure of extraction port and temperature difference of heater have no change, it analyzes the influence of changes in extraction steam pressure loss to heat system. According to the theoretical analysis of extraction steam pressure loss and steam water distribution equation of heat system, it establishes the mathematical model about the influence of extraction steam pressure loss to abstract coefficient of reheating system. The mathematical model about the influence of extraction steam pressure loss to exergy loss distribution is established combining exergy balance principle and theory of small disturbance. The change on exergy loss of heat system is calculated in quantity on N 1 000-25/600/600 unit thermal system at TRL condition. The effect of extraction steam pressure loss to heat system is qualitative analyzed according to quantitative results.