1000MW超超临界汽轮机热应力监测及自动控制

Thermal stress monitoring & control in 1000 MW ultra-supercritical steam turbine

热应力监测和控制对保障汽轮机组的安全运行、延长寿命周期有着重要作用。西门子1000MW超超临界汽轮机采用温度测量来确定高压主汽门、高压调门及高压外缸的部件温差,采用简化的仿真计算确定高、中压转子的部件温差,以温差表征相应部件热应力的大小,并通过温度裕量的计算确定热应力是否超限。在机组实际运行中从4个方面自动控制汽轮机的热应力:启动阶段的多个X准则判断、冲转时的高压级压力控制、全过程转速(负荷)变化速率限制和主蒸汽/再热蒸汽最佳温度控制。

Thermal stress monitoring and control is a vital technology- in steam turbine control system, and it is crucial for safe operation and life cyele. In Siemens 1 000 MW uhra-superefitical steam turbine, the temperature measurement is applied to determine the temperature difference in HP ESV, HP CV and HP easing; meanwhile, the simplified simulation is used to obtain the temperature difference in HP rotor and IP rotor. These temperature diferences represent the magnitude of thermal stress in related components. Furthermore the temperature margins are introduced to conffirm whether the thermal stress is overrange. The thermal stress is always under automatic control through whole process by the four means： several X criterions in startup process, HP blade pressure control, limit of speed or load change rate in overall proeess, and optimal temperature control of main steam and reheat steam.