直冷式空冷机组的负荷-压力动态模型及其特性分析

在对空冷装置、汽轮机及回热加热系统进行研究的基础上,结合传统机组非线性动态模型,引入汽轮机效率修正,得到能够体现排汽压力变化特性的空冷机组通用动态模型,并给出了1台600 MW机组的实例.分析了采用机跟炉和炉跟机2种控制方式时排汽压力波动造成的影响.结果表明:排汽压力快速变化是影响机组负荷-压力稳定的一个重要原因;而排汽压力缓慢变化导致的被控对象参数改变不会对控制品质产生实质性影响.

Load-Pressure Dynamic Model and Its Features Analysis of Direct Air-cooling Unit

Based on analysis of air-cooling device,turbine and the regenerative heater system,reference to the traditional unit nonlinear dynamic model,considering turbine efficiency amending,universal dynamic model of direct air-cooling unit,which can embody exhaust steam pressure change characteristic,is obtained.A 600MW unit model was introduced.Using turbine following and boiler following two control modes,the effect of exhaust steam pressure fluctuation response to system,was analyzed respectively.The simulation results show that exhaust steam pressure quickly changing is an important factor to affect unit load-pressure system stability,but the nonlinearity caused by object parameters changed with the exhaust steam pressure slowly changing will not affect system control performance essentially.