大机组实现FCB的现实性及技术分析

从预防电网大面积停电出发,阐述了火电大机组实现FCB功能的现实意义。该功能可使机组在电网突发故障时,迅速转为带厂用电作孤岛运行,并可随时恢复向外送电,包括为其他火电机组提供厂用电进行再启动,从而缩短了电网恢复时间。同时还降低了机组的故障率,提高了超(超)临界机组的可靠性。通过对外高桥电厂二期900MW超临界机组实现FCB的实例介绍,证明了火电大机组实现FCB的可行性。结合外高桥电厂三期2×1000MW工程,就实现FCB的各项条件作了进一步的分析和讨论,如机组连锁保护的设计、旁路容量的配置、除氧水箱容量的选取、厂用电切换方式、汽动给水泵汽源切换、控制系统的协调配合、负荷调节方式等。

The Realism and Technical Analysis of Implementing FCB for the Large Coal-fired Power Units

In order to deal with the grid failure on a large area, this study elaborates the importance of implementing FCB for the large coal fired power units. This function makes the unit run with the station power only as the grid failure suddenly, and it can resume power supply to the grid at any time, include providing station power for the other coal-fired power unit for its restart-up. It greatly shortens the grid recovery time. At the same time this function reduces the unit failure rate and enormously improves the reliability of ultra-supercritical power units. Through the successful FCB case introduction of Waigaoqiao phase 2 supercritical 900MW unit, it proves the feasibility to realize the large unit FCB. In addition, combining with Waigaoqiao phase III 2X1000MW project, it makes the further analysis and discussion with every condition to fulfill unit FCB. For example, the design of the unit protection and interlock, the suitable Bypass capacity, the selection of the Deaerator tank volume, the switch mode of the station power, the steam switch over for the Boiler Feed Pump Turbine, the suitable control philosophy and logic, the load adjust mode, etc.