中文摘要：

加热器端差受人口温度、机组负荷等因素的影响，现场需要及时了解加热器变工况特性。基于量纲分析理论，分别对加热器疏水冷却段、凝结段及过热蒸汽冷却段进行模块化建模，将各段传热单元数简化表示为某一参数的线性函数，模型对三段式高加和两段式低加的变工况特性的计算均适用。将模型应用于某330MW机组1号高加和5号低加，将计算的上、下端差与该机组大修后试验数据进行对比验证，并对两台加热器变工况特性进行了分析，为现场获取不同类型加热器变工况特性提供了参考。

英文摘要：

The terminal temperature difference of beater is affected by many influence factors, such as the beater tube inlet temperature, the turbine load, etc. The drain cooler, condensing section and superheated cooling section of feedwater heater were modular modelled based on dimensional analysis, and the number of transfer unit of each section was expressed as a linear function of a parameter. The model was applicable to both the calculation of high pressure heater and low pressure heater. The model was applied to No. 1 high pressure heater and #5 low pressure heater of a 330MW turbine respectively, and the calculated terminal temperature difference and drain cooler approach temperature difference were compared with operation data. The analysis for result and the model provide a reference for the varying condition characteristic calculation of different heaters.