超超临界二次再热机组再热蒸汽温度模型辨识

Reheat steam temperature model identification of ultra supercritical unit with double reheat cycles

二次再热机组锅炉再热蒸汽温度(再热汽温)动态特性与一次再热机组差异较大。本文基于由仿真支撑软件APROS和虚拟控制器VDCS搭建的超临界1 000 MW二次再热机组仿真平台,结合差分进化算法和广义损失函数,编制再热汽温模型辨识程序,对再热汽温系统进行扰动试验,得到100%和75%额定工况下烟气调节挡板开度、烟气再循环挡板开度以及再热器喷水阀开度扰动下的再热汽温传递函数模型。仿真结果表明,该再热汽温模型辨识精度高,且传递函数模型能很好地解释再热汽温在各扰动下的动态特性。

Due to the complexity and particularity of double-reheat unit＇s boiler construction,the dynamic characteristics of reheat steam temperature changes greatly compared with the unit with single reheat cycle.On the simulation platform of ultra-supercritical（USC）1 000 MW unit with double-reheat that adopts APROS software and virtual controller VDCS,the reheat steam temperature model identification program was established,and disturbance test for the reheat steam temperature system was also carried out,combining the differential evolution algorithm with the generalized loss function definition.The transfer function models of reheat steam temperature with disturbance of flue gas damper opening degree,flue gas recirculation damper opening degree and spray dereheating valve opening degree were obtained,under conditions with 100%ECR and 75%ECR load.The results show that,the reheat steam temperature model has high identification accuracy,and the transfer function model can well explain the dynamic characteristics of the reheat steam temperature under different disturbances.It is of great significance to formulate the control strategy of reheat steam temperature of actual units.