基于简化模型的回热系统性能实时监测

Real-time Monitoring of Regenerative System Performance Based on Simplified Mode

回热系统是发电机组的主要辅助设备,实时监测回热系统的运行状况,对机组的安全性、经济性具有重要意义。由于在变工况条件下,电站回热加热器不同换热段的换热特性具有明显差异,且回热系统各参数具有鲜明的耦合关系。传统的回热系统传热计算过程复杂,致使回热系统的整体变工况特性计算不易收敛,或精度降低。针对典型的三段式回热加热器建立了变工况简化计算模型,同时,以300MW机组的回热系统为例,结合疏水冷却段效能的简化计算方法与回热系统变工况的逆序算法进行了计算分析。计算结果表明模型精度较高,同时该模型具有对现场测点数据依赖度小、计算方法简单、速度快的优点,对回热系统性能监测以及机组热经济性诊断具有一定的参考价值。

The regenerative system is the main auxiliary equipment of power unit. And it has important significance for unit g security and economy to monitor the operation status of the heat recovery system. The heat transfer characteristics of the different heat exchange section of the power station are obviously different, and the parameters of the regenerative heating system have distinct coupling relationship under variable working conditions. The integral variable condition characteristic of the regenerative system is not easy to converge, and the precision is reduced because traditional the calculation process of heat transfer is complex in regenerative system. A simplified calculation model of variable working condition is established for typical three stage regenerative heater in this paper. Combined with the hydrophobic cooling section effectiveness of simplified calculation method and regenerative system variable condition of reverse algorithm 300MW unit regenerative system are calculated and analyzed. The calculation results show that the model has a high accuracy and the advantages of small dependence on the spot measurement data, simple calculation method and fast speed. It has some reference value for the performance monitoring of the regenerative system and the economic diagnosis of the unit.