Novel coordinated control method with coal-quality correction of circulating field bed boiler
To improve the load-following capability and the coal-quality applicability of a circulating field bed boiler (CFBB), a new coordinated control method with coal-quality correction is proposed in this paper. This method takes the primary air as another new control variable into the coordinated control of CFBB, which can take advantage of the unburned carbon in bed to improve its load-following capability. Simultaneously, a multivariable predictive controller based on augmented state space model is designed to deal with the CFBB's characteristics such as time-delay and strong coupling. Finally, an improved strategy to correct coal-quality online based on the disturbance observer is provided. Compared with the conventional control scheme, the simulation results for a 330MW CFBB shows that the method proposed in this paper can significantly improve the load-following capability and the coal-quality applicability.
Study of the neural network generalized predictive control for the circulating fluidized bed boiler generator
The circulating fluidized bed boiler (CFBB) generator has following characteristics: multi-variable, non-linear, strong coupling, time-varying characteristics. The combustion is still in the fluidized state, so its control is more complex, the traditional PID control effect is not ideal. This paper proposes a good nonlinear function approximation of BP neural network. Because the convergence rate of BP network is slower, a combination method with changing step and inducting momentum is used to improve the convergence rate. Meanwhile this paper achieve generalized predictive control (GPC) with online rolling optimization and real time feedback revision. Simulation results demonstrate the effectiveness of this algorithm.
Analysis on supercritical technology of large circulating fluidized bed boiler and difficult points in its control
The characteristics of CFB boiler in fitting to the supercritical parameters,the difficult points of automatic control technology and the key technologies were analyzed.The present development of supercritical CFB boiler at home and abroad was introduced.The authors consider that the good development prospect of the supercritical CFB boiler in our country is expectable,but the problem of automatic control under parameters strong coupling must be solved firstly.