考虑水位影响的蒸汽动力发电机组给水加热器变工况特性

Varying Condition Characteristic of Feedwater Heater Considering Liquid Level in Steam Power Generating Unit

基于量纲分析建立三段式加热器变工况数学模型,并将其结合疏水混入蒸汽后疏冷段传热系数的变化建立加热器低水位运行特性模型;以某330MW机组#1高压加热器为例,应用模型分别计算正常水位变工况运行端差、低水位运行疏冷段换热系数及端差特性;将计算结果与试验数据对比验证,定量分析了加热器端差随水位及负荷的变化规律,并重新设定安全水位和经济水位。为了解加热器低水位运行特性,实现对水位的及时调整提供参考。

A mathematical model of three-section heater for varying condition was established based on dimensional analysis. The operation characteristic of low liquid level was modelled with the calculation of heat transfer coefficient of drain cooler mixed with steam. Taking #1 high pressure feedwater heater of a 330 MW steam turbine for example, the model was used to calculate the terminal temperature difference of regular liquid level, the heat transfer condition of drain cooler and the terminal temperature difference of low liquid level. The calculation results were verified by the experimental data. The influence of liquid level and power load on terminal temperature difference was also quantitativly analyzed, and the security level and economic level were reseted. The research provides a reference for analyzing the operation characteristic of low liquid level and adjusting liquid level timely.