330MW单元机组燃烧控制系统优化设计

Optimized design of 330MW unit combustion control system

火电大机组的燃烧控制系统是一个相互关联的多变量耦合系统。在负荷变化时风、煤如何配合,使其既能快速响应负荷需求又能保证燃烧的经济性,这就需要将燃烧控制系统作为一个协调的整体加以考虑,根据锅炉及燃烧设备类型设计出最合理的控制方案。介绍一种基于精确配风的串级燃烧控制系统,采用精确配风的方案可以使风量更准确、迅速地配合煤量的变化,而采用串级燃烧控制系统则可以更好地保证燃烧的经济性。在控制系统投运后,为了解决风、煤自发性扰动对对方的影响,在控制系统中引入解耦算法;针对启、停磨煤机时煤量的扰动,在燃料量主控回路中增加一个超驰回路以平衡煤量的扰动;对于特殊原因造成给煤机控制品质恶劣的情况,采取积分分离PID算法代替传统PID算法,以上优化方案的应用在实践中取得了较好的控制效果。

The combustion control system of power plant is a coupling system of multiple variables.In cooperating coal and air to respond the load requirement fast and to ensure the economic firing during the load changing ,the combustion control system should be taken into account as one entity according to the type of boiler and the combustion system.A cascade combustion control system based on the accurate distribution of air is designed for this purpose.When it is put into operation ,the de - coupling algorithm is applied to reduce the influence between coal and air when they produce the self - disturbances ,and an override loop is used to restrain the coal disturbance during the period of mill startup or shutdown.The traditional PID algorithm is replaced by the separated integrator PID algorithm to control feeder speed loops with worse dynamic characteristic.The application of these optimizing methods gets a good result.